Dissertations / Theses: 'MDA-MB-231'

1

Esmaeili, Pourfarhangi Kamyar. "Movie8: FUCCI-MDA-MB-231 cells migration on 2D gelatin." Diss., Cancer Invasion; Cell Migration; Chemotaxis; Contact Guidance; Invadopodia; Mechanobiology, 2019. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/584750.

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Abstract:

Bioengineering;
Ph.D.;
Metastasis is the leading cause of death among cancer patients. The metastatic cascade, during which cancer cells from the primary tumor reach a distant organ and form multiple secondary tumors, consists of a series of events starting with cancer cells invasion through the surrounding tissue of the primary tumor. Invading cells may perform proteolytic degradation of the surrounding extracellular matrix (ECM) and directed migration in order to disseminate through the tissue. Both of the mentioned processes are profoundly affected by several parameters originating from the tumor microenvironment (extrinsic) and tumor cells themselves (intrinsic). However, due to the complexity of the invasion process and heterogeneity of the tumor tissue, the exact effect of many of these parameters are yet to be elucidated. ECM proteolysis is widely performed by cancer cells to facilitate the invasion process through the dense and highly cross-linked tumor tissue. It has been shown in vivo that the proteolytic activity of the cancer cells correlates with the cross-linking level of their surrounding ECM. Therefore, the first part of this thesis seeks to understand how ECM cross-linking regulates cancer cells proteolytic activity. This chapter first quantitatively characterizes the correlation between ECM cross-linking and the dynamics of cancer cells proteolytic activity and then identifies ß1-integrin subunit as a master regulator of this process. Once cancer cells degrade their immediate ECM, they directionally migrate through it. Bundles of aligned collagen fibers and gradients of soluble growth factors are two well-known cues of directed migration that are abundantly present in tumor tissues stimulating contact guidance and chemotaxis, respectively. While such cues direct the cells towards a specific direction, they are also known to stimulate cell cycle progression. Moreover, due to the complexity of the tumor tissue, cells may be exposed to both cues simultaneously, and this co-stimulation may happen in the same or different directions. Hence, in the next two chapters of this thesis, the effect of cell cycle progression and contact guidance-chemotaxis dual-cue environments on directional migration of invading cells are assessed. First, we show that cell cycle progression affects contact guidance and not random motility of the cells. Next, we show how exposure of cancer cells to contact guidance-chemotaxis dual-cue environments can improve distinctive aspects of cancer invasion depending on the spatial conformation of the two cues. In this dissertation, we strive to achieve the defined milestones by developing novel mathematical and experimental models of cancer invasion as well as utilizing fluorescent time-lapse microscopy and automated image and signal processing techniques. The results of this study improve our knowledge about the role of the studied extrinsic and intrinsic cues in cancer invasion.
Temple University--Theses

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2

Esmaeili, Pourfarhangi Kamyar. "Movie9: FUCCI-MDA-MB-231 cells migration inside the microchannels." Diss., Cancer Invasion; Cell Migration; Chemotaxis; Contact Guidance; Invadopodia; Mechanobiology, 2019. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/584759.

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Abstract:

Bioengineering;
Ph.D.;
Metastasis is the leading cause of death among cancer patients. The metastatic cascade, during which cancer cells from the primary tumor reach a distant organ and form multiple secondary tumors, consists of a series of events starting with cancer cells invasion through the surrounding tissue of the primary tumor. Invading cells may perform proteolytic degradation of the surrounding extracellular matrix (ECM) and directed migration in order to disseminate through the tissue. Both of the mentioned processes are profoundly affected by several parameters originating from the tumor microenvironment (extrinsic) and tumor cells themselves (intrinsic). However, due to the complexity of the invasion process and heterogeneity of the tumor tissue, the exact effect of many of these parameters are yet to be elucidated. ECM proteolysis is widely performed by cancer cells to facilitate the invasion process through the dense and highly cross-linked tumor tissue. It has been shown in vivo that the proteolytic activity of the cancer cells correlates with the cross-linking level of their surrounding ECM. Therefore, the first part of this thesis seeks to understand how ECM cross-linking regulates cancer cells proteolytic activity. This chapter first quantitatively characterizes the correlation between ECM cross-linking and the dynamics of cancer cells proteolytic activity and then identifies ß1-integrin subunit as a master regulator of this process. Once cancer cells degrade their immediate ECM, they directionally migrate through it. Bundles of aligned collagen fibers and gradients of soluble growth factors are two well-known cues of directed migration that are abundantly present in tumor tissues stimulating contact guidance and chemotaxis, respectively. While such cues direct the cells towards a specific direction, they are also known to stimulate cell cycle progression. Moreover, due to the complexity of the tumor tissue, cells may be exposed to both cues simultaneously, and this co-stimulation may happen in the same or different directions. Hence, in the next two chapters of this thesis, the effect of cell cycle progression and contact guidance-chemotaxis dual-cue environments on directional migration of invading cells are assessed. First, we show that cell cycle progression affects contact guidance and not random motility of the cells. Next, we show how exposure of cancer cells to contact guidance-chemotaxis dual-cue environments can improve distinctive aspects of cancer invasion depending on the spatial conformation of the two cues. In this dissertation, we strive to achieve the defined milestones by developing novel mathematical and experimental models of cancer invasion as well as utilizing fluorescent time-lapse microscopy and automated image and signal processing techniques. The results of this study improve our knowledge about the role of the studied extrinsic and intrinsic cues in cancer invasion.
Temple University--Theses

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3

Esmaeili, Pourfarhangi Kamyar. "Movie2: MDA-MB-231 cell switching between Migration and Invadopodia states." Diss., Temple University Libraries, 2019. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/584754.

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Abstract:

Bioengineering;
Ph.D.;
Metastasis is the leading cause of death among cancer patients. The metastatic cascade, during which cancer cells from the primary tumor reach a distant organ and form multiple secondary tumors, consists of a series of events starting with cancer cells invasion through the surrounding tissue of the primary tumor. Invading cells may perform proteolytic degradation of the surrounding extracellular matrix (ECM) and directed migration in order to disseminate through the tissue. Both of the mentioned processes are profoundly affected by several parameters originating from the tumor microenvironment (extrinsic) and tumor cells themselves (intrinsic). However, due to the complexity of the invasion process and heterogeneity of the tumor tissue, the exact effect of many of these parameters are yet to be elucidated. ECM proteolysis is widely performed by cancer cells to facilitate the invasion process through the dense and highly cross-linked tumor tissue. It has been shown in vivo that the proteolytic activity of the cancer cells correlates with the cross-linking level of their surrounding ECM. Therefore, the first part of this thesis seeks to understand how ECM cross-linking regulates cancer cells proteolytic activity. This chapter first quantitatively characterizes the correlation between ECM cross-linking and the dynamics of cancer cells proteolytic activity and then identifies ß1-integrin subunit as a master regulator of this process. Once cancer cells degrade their immediate ECM, they directionally migrate through it. Bundles of aligned collagen fibers and gradients of soluble growth factors are two well-known cues of directed migration that are abundantly present in tumor tissues stimulating contact guidance and chemotaxis, respectively. While such cues direct the cells towards a specific direction, they are also known to stimulate cell cycle progression. Moreover, due to the complexity of the tumor tissue, cells may be exposed to both cues simultaneously, and this co-stimulation may happen in the same or different directions. Hence, in the next two chapters of this thesis, the effect of cell cycle progression and contact guidance-chemotaxis dual-cue environments on directional migration of invading cells are assessed. First, we show that cell cycle progression affects contact guidance and not random motility of the cells. Next, we show how exposure of cancer cells to contact guidance-chemotaxis dual-cue environments can improve distinctive aspects of cancer invasion depending on the spatial conformation of the two cues. In this dissertation, we strive to achieve the defined milestones by developing novel mathematical and experimental models of cancer invasion as well as utilizing fluorescent time-lapse microscopy and automated image and signal processing techniques. The results of this study improve our knowledge about the role of the studied extrinsic and intrinsic cues in cancer invasion.
Temple University--Theses

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4

Yaourtis, Andria. "Innate and anti-cancer drug-induced morphological changes in the human breast cancer cell line MDA-MB-231." Thesis, The University of Sydney, 2021. https://hdl.handle.net/2123/26409.

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Phenotypic changes in tumour cells is a well-established phenomenon and can happen either naturally or in response to a drug. Such changes in phenotype are often accompanied with changes in the behaviour of tumour cells, including growth, proliferation, as well as their migratory and invasive capacity. Phenotypic changes can, therefore, impact the aggressiveness of the tumour cell and dictate their metastatic potential. Thus, it is of utmost importance to fully understand and characterise phenotypic changes in tumour cells in order to better understand tumour progression and identify therapeutic targets. The research described in this thesis focused on morphological changes in the human breast cancer cell line, MDA-MB-231, arising from two conditions: a spontaneous, natural transformation that cells undergo, and a transformation induced by the gallium complex, tris(8-hydroxyquinolinato)gallium(III) [GaQ3]. Techniques utilised in this study included digital holographic microscopy, scanning electron microscopy, confocal microscopy, short tandem repeat profiling, migration and invasion wound healing assays, as well as Fourier transform infrared spectroscopy. It was found that whether the cell undergoes natural or drug-induced morphological changes, the changes in cell phenotypes are accompanied with functional changes, with the most significant functional change being a reduction in the cell’s invasive potential. Further, phenotypic changes that MDA-MB-231 cells may naturally undergo were likely to be induced by the release and uptake of extracellular vesicles. The findings of this thesis, therefore, have significant implications in understanding cancer metastasis, and opens new avenues for the intervention of possible anti-metastatic therapies.

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5

Lymburner, Sylvia. "Zinc inhibits magnesium-mediated human breast cancer MDA-MB-231 cell migration on fibronectin." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/37064.

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Breast cancer is the most prevalent type of cancer in Canadian women and ranks second in mortality. The cause of breast cancer deaths is the tumor growth in secondary locations. Zinc has been suggested to alter the affinity by which cells attach to the extracellular matrix. The strength of cell adhesion is paramount to the ability of cancerous cells to migrate. The hypothesis for my thesis research was that zinc promotes the metastasic potential of human breast cancer cells. The overall objective of my thesis research was to characterize the effects of zinc on the growth and metastatic potential of human breast cancer cells. Breast carcinoma MDA-MB-231 cells were cultured in DMEM plus 10% Chelex-100 treated FBS supplemented with 0 (zinc-deficient medium), 5 (zinc-adequate medium), or 25 (zinc-supplemented medium) µmol/L of Zn²⁺ as ZnSO₄. After culture for 96 h, the cells were harvested for determining total cellular zinc concentration, abundance of the labile intracellular pool of zinc, and cell growth. The metastatic potential of the cells was assessed by a combination of migration rate assessed using the wound-healing assay and migration distance using the single cell migration assay. The cells were also assessed for their adhesion on fibronectin, for the involvement of specific integrin subunits using blocking antibody, and integrin activation using FACS. Zinc treatments had no effect on total cellular zinc concentration, cell growth, and viability and essentially had no effect on abundance of the labile intracellular pool of zinc. Zinc as low as 5 µmol/L inhibited MDA-MB-231 cell migration on fibronectin, reduced magnesium-mediated promotion of adhesion and thus was likely involved in inhibiting magnesium-mediated integrin activation. With the use of blocking antibodies, it was determined that α5/β1 integrin was responsible for the adhesion of the cells to fibronectin and it was likely that zinc inhibited adhesion by blocking the activation of this specific form of integrin. Together these results suggested that zinc was an inhibitor of MDA-MB-231 migration on fibronectin, and thus likely an inhibitor of metastases, contrary to the hypothesis.

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6

Esmaeili, Pourfarhangi Kamyar. "Movie11: FUCCI-MDA-MB-231 cells migration in 3D collagen with random fiber architecture." Diss., Temple University Libraries, 2019. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/584757.

Full text

Abstract:

Bioengineering;
Ph.D.;
Metastasis is the leading cause of death among cancer patients. The metastatic cascade, during which cancer cells from the primary tumor reach a distant organ and form multiple secondary tumors, consists of a series of events starting with cancer cells invasion through the surrounding tissue of the primary tumor. Invading cells may perform proteolytic degradation of the surrounding extracellular matrix (ECM) and directed migration in order to disseminate through the tissue. Both of the mentioned processes are profoundly affected by several parameters originating from the tumor microenvironment (extrinsic) and tumor cells themselves (intrinsic). However, due to the complexity of the invasion process and heterogeneity of the tumor tissue, the exact effect of many of these parameters are yet to be elucidated. ECM proteolysis is widely performed by cancer cells to facilitate the invasion process through the dense and highly cross-linked tumor tissue. It has been shown in vivo that the proteolytic activity of the cancer cells correlates with the cross-linking level of their surrounding ECM. Therefore, the first part of this thesis seeks to understand how ECM cross-linking regulates cancer cells proteolytic activity. This chapter first quantitatively characterizes the correlation between ECM cross-linking and the dynamics of cancer cells proteolytic activity and then identifies ß1-integrin subunit as a master regulator of this process. Once cancer cells degrade their immediate ECM, they directionally migrate through it. Bundles of aligned collagen fibers and gradients of soluble growth factors are two well-known cues of directed migration that are abundantly present in tumor tissues stimulating contact guidance and chemotaxis, respectively. While such cues direct the cells towards a specific direction, they are also known to stimulate cell cycle progression. Moreover, due to the complexity of the tumor tissue, cells may be exposed to both cues simultaneously, and this co-stimulation may happen in the same or different directions. Hence, in the next two chapters of this thesis, the effect of cell cycle progression and contact guidance-chemotaxis dual-cue environments on directional migration of invading cells are assessed. First, we show that cell cycle progression affects contact guidance and not random motility of the cells. Next, we show how exposure of cancer cells to contact guidance-chemotaxis dual-cue environments can improve distinctive aspects of cancer invasion depending on the spatial conformation of the two cues. In this dissertation, we strive to achieve the defined milestones by developing novel mathematical and experimental models of cancer invasion as well as utilizing fluorescent time-lapse microscopy and automated image and signal processing techniques. The results of this study improve our knowledge about the role of the studied extrinsic and intrinsic cues in cancer invasion.
Temple University--Theses

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Lima, Benedicto Augusto Vieira. "Avaliação das atividades citotóxicas de alguns complexos fosfínicos de rutênio (Células tumorais MDA-MB 231)." Universidade Federal de São Carlos, 2010. https://repositorio.ufscar.br/handle/ufscar/6465.

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In this thesis complexes of general formula: [Ru(NS)(bipy)(PP)]PF6 (NS = 2-mercaptopyridine, 2-mercaptopyrimidine, 4,6-dimethyl-2- mercaptopyrimidine and PP = dppf, dppp, dppe); [Ru(pic)(bipy)(PP)]PF6 (pic = picolinate; PP = dppf, dppp, dppe and dppm), [RuCl(bCN)(bipy)(PP)]PF6 (bCN = benzonitrile; PP = dppf and dppe), and [RuCl(bCN)(NN)(dppb)]PF6 (NN = bipy, Mebipy and phen), were synthesised from the precursor complexes cis- [RuCl2(NN)(PP)] and characterized by the usual techniques: 1H and 31P{1H} NMR, IR, UV-Vis, molar conductimetry, elemental analysis, cyclic and differential pulse voltammetry and single-crystal X-ray diffraction (except for the compounds [Ru(pic)(bipy)(dppp)]PF6, [Ru(pic)(bipy)(dppm)]PF6 and [RuCl(bCN)(Mebipy)(dppb)]PF6, which suitable single crystal were not obtained). The 31P{1H} NMR spectras of the new compounds showed that the phosphorus atoms were more deshielded than in the correspondent precursor. The E1/2 values of the complexes containing the ligands NS, pic and bCN were higher than those observed in the precursor complexes. The complexes containing the ligand dppf presented two redox process, which were assigned to the redox pairs FeII/FeIII and RuII/RuIII respectively, according to the results of the kinetics experiments monitored by differential pulse voltammetry and 31P{1H} NMR techniques. The molar conductimetry and elemental analysis assays corroborated the proposed formula and the single-crystal X-ray diffraction study of these complexes confirmed their structures. The νCN in the complexes [RuCl(bCN)(NN)(PP)]PF6 were higher (~+8 cm-1) than that observed in the free ligand (2229 cm-1). Also, it was avaluated in vitro antitumor activity of some of the compounds synthesised herein against mammary cancer cell line (MDA-MB-231), murine sarcoma, as well as against M. tuberculosis (H37Rv); some of them presented high activity.
Neste trabalho foram sintetizados os complexos de fórmula: [Ru(NS)(bipy)(PP)]PF6 (NS = 2-mercaptopiridina, 2-mercaptopirimidina, 4,6- dimetil-2-mercaptopirimidina e PP = dppf, dppp, dppe); [Ru(pic)(bipy)(PP)]PF6 (PP = dppf, dppp, dppe e dppm), [RuCl(bCN)(bipy)(PP)]PF6 (bCN = benzonitrila; PP = dppf e dppe), e [RuCl(bCN)(NN)(dppb)]PF6 (NN = bipy, Mebipy e phen) a partir dos complexos precursores de fórmula cis- [RuCl2(NN)(PP)], e foram caracterizados pelas técnicas de RMN de 1H e 31P{1H}, IV, UV-Vis, condutância molar, análise elementar, voltametrias cíclica e de pulso diferencial e por difração de raios-X de monocristal (à exceção dos compostos [Ru(pic)(bipy)(dppp)]PF6, [Ru(pic)(bipy)(dppm)]PF6, [RuCl(bCN)(Mebipy)(dppb)]PF6, dos quais não se obteve cristais adequados para estudado por difração de raios-X). Os espectros de RMN de 31P{1H} mostraram que ocorre a desblindagem dos átomos de fósforo causada pela coordenação dos ligantes NS, pic e bCN. Os complexos sintetizados apresentaram valores de E1/2 maiores que seus correspondentes precursores, e aqueles contendo a bifosfina dppf apresentaram dois processos redox, que através de experimentos de cinética realizados por voltametria de pulso diferencial e RMN de 31P{1H} puderam ser atribuídos aos pares FeII/FeIII e RuII/RuIII, respectivamente. As medidas de condutância molar e as de análise elementar corroboraram as fórmulas propostas e o estudo dos cristais resolvidos por difração de raios-X confirmaram as estruturas esperadas. Os valores de νCN nos complexos [RuCl(bCN)(NN)(PP)]PF6 foram maiores (~+8 cm-1) que o observado no ligante bCN livre (2229 cm-1). Alguns dos complexos sintetizados neste trabalho também foram avaliados in vitro como agentes antitumorais contra a linhagem de células de câncer de mama MDA-MB-231, sarcoma murino e também como anti-M. tuberculosis (H37Rv); alguns deles mostraram bons resultados.

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Esmaeili, Pourfarhangi Kamyar. "Movie12: FUCCI-MDA-MB-231 cells migration in 3D collagen with vertically aligned fiber architecture." Diss., Temple University Libraries, 2019. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/584747.

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Abstract:

Bioengineering;
Ph.D.;
Metastasis is the leading cause of death among cancer patients. The metastatic cascade, during which cancer cells from the primary tumor reach a distant organ and form multiple secondary tumors, consists of a series of events starting with cancer cells invasion through the surrounding tissue of the primary tumor. Invading cells may perform proteolytic degradation of the surrounding extracellular matrix (ECM) and directed migration in order to disseminate through the tissue. Both of the mentioned processes are profoundly affected by several parameters originating from the tumor microenvironment (extrinsic) and tumor cells themselves (intrinsic). However, due to the complexity of the invasion process and heterogeneity of the tumor tissue, the exact effect of many of these parameters are yet to be elucidated. ECM proteolysis is widely performed by cancer cells to facilitate the invasion process through the dense and highly cross-linked tumor tissue. It has been shown in vivo that the proteolytic activity of the cancer cells correlates with the cross-linking level of their surrounding ECM. Therefore, the first part of this thesis seeks to understand how ECM cross-linking regulates cancer cells proteolytic activity. This chapter first quantitatively characterizes the correlation between ECM cross-linking and the dynamics of cancer cells proteolytic activity and then identifies ß1-integrin subunit as a master regulator of this process. Once cancer cells degrade their immediate ECM, they directionally migrate through it. Bundles of aligned collagen fibers and gradients of soluble growth factors are two well-known cues of directed migration that are abundantly present in tumor tissues stimulating contact guidance and chemotaxis, respectively. While such cues direct the cells towards a specific direction, they are also known to stimulate cell cycle progression. Moreover, due to the complexity of the tumor tissue, cells may be exposed to both cues simultaneously, and this co-stimulation may happen in the same or different directions. Hence, in the next two chapters of this thesis, the effect of cell cycle progression and contact guidance-chemotaxis dual-cue environments on directional migration of invading cells are assessed. First, we show that cell cycle progression affects contact guidance and not random motility of the cells. Next, we show how exposure of cancer cells to contact guidance-chemotaxis dual-cue environments can improve distinctive aspects of cancer invasion depending on the spatial conformation of the two cues. In this dissertation, we strive to achieve the defined milestones by developing novel mathematical and experimental models of cancer invasion as well as utilizing fluorescent time-lapse microscopy and automated image and signal processing techniques. The results of this study improve our knowledge about the role of the studied extrinsic and intrinsic cues in cancer invasion.
Temple University--Theses

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Whitehurst, Brandt D. "VEGF-A modulates lymphangiogenic mechanisms in an orthotopic model of human breast carcinoma MDA-MB-231 /." Available to subscribers only, 2006. http://proquest.umi.com/pqdweb?did=1136079881&sid=25&Fmt=2&clientId=1509&RQT=309&VName=PQD.

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Thesis (M.S.)--Southern Illinois University Carbondale, 2006.
"Department of Molecular Biology, Microbiology and Biochemisty." Includes bibliographical references (leaves 52-71). Also available online.

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Luvizon, Aline Carbonera [UNESP]. "Mecanismo de ação do estrógeno no gene Amphiregulin em células MCF7 e MDA-MB-231 via P13K." Universidade Estadual Paulista (UNESP), 2014. http://hdl.handle.net/11449/123271.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
A importância do estrógeno (E2) no desenvolvimento do câncer de mama é bem estabelecido na literatura. O uso de antagonistas de E2 para o tratamento de tumores positivos para o receptor de estrógeno mostra-se importante para a sobrevida de pacientes acometidas pela doença. Amphiregulin (Areg), um fator de crescimento regulador multifuncional que pode ser induzido por estrógeno, possui papel central no desenvolvimento da glândula mamária e na morfogênese de órgãos e é expresso tanto em tecidos normais como cancerosos. Estudos clínicos sugerem que amphiregulin também desempenha papel importante na progressão do câncer da mama humano e a sua expressão aumentada tem sido associada com doença agressiva. Para investigar o mecanismo pelo qual o E2 induz a expressão de AREG, células MCF-7 e MDA-MB-231 foram tratadas durante 10 minutos, 30 minutos, 1 hora e 4 horas com veículo (controle) ou E2 isoladamente ou em associação com Fulvestrant (ICI, inibidor do receptor de estrógeno), Actinomicina D (ACTD, inibidor da transcrição gênica), Ciclohexamida (CHX, inibidor da síntese proteica) ou LY (inibidor da via PI3K). Os inibidores também foram utilizados isoladamente. O RNAm foi extraído das células pelo método de trizol e a expressão de AREG foi analisada por qRT-PCR. O tratamento de ambas as células com E2 induziu aumento do RNAm de AREG em todos os tempos analisados. Esse aumento foi parcialmente dependente de ER nas células MCF-7 nos tempos de 10 minutos, 1 e 4 horas. Em 30 minutos não foi observado a ligação do E2 com o ER para que houvesse o aumento da expressão do gene alvo. Nas células MDA-MB-231 o estrógeno aumentou o RNAm de AREG por pelo menos duas vias distintas em todos tempos analisados. Uma das vias ativa a via PI3K para que este efeito ocorra. Nossos resultados demonstram que o E2 é capaz de induzir a expressão de AREG em linhagens de células de câncer de ...
The relevance of estrogen in breast cancer development is well established in the literature. The use of E2 antagonists for ER-positive breast cancer treatment is shown to be important to patients´ survival. Amphiregulin, a multifunctional growth regulator factor that may be induced by estrogen plays a central role in development of mammary glands and organ morphogenesis, is expressed in both normal and cancerous tissues. Clinical studies suggest that amphiregulin also is important in human breast cancer progression and its expression has been associated with aggressive disease. To investigate the mechanism whereby E2 induces AREG expression, MCF-7 and MDA-MB-231 cells were treated for 10 minutes, 30 minutes, 1 hour or 4 hours with vehicle (control) or estrogen (E2) isolated or in association with Fulvestrant (ICI, estrogen receptor inhibitor), Actinomycin D (ACTD, gene transcription inhibitor), Cycloheximide (CHX, protein synthesis inhibitor ) or LY (PI3K inhibitor). The inhibitors were also used alone. mRNA was extracted from the cells by the Trizol method and AREG expression analyzed by qRT-PCR. Treatment of both cell types with E2 increased AREG mRNA expression at all moments. This increase was partially ER-dependent in MCF- 7 cells at 10 minutes, 1 and 4 hours. At 30 min, no binding of E2 to ER was obseved. In MDA-MB-231 cells, the estrogen-induced AREG mRNA was enhanced by two distinct pathways at the moments analyzed and PI3K pathways participated in one of them. Our results showed that E2 was able to induce the AREG expression in breast cancer cell lines in an ER-dependent and -independent manner

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Luvizon, Aline Carbonera. "Mecanismo de ação do estrógeno no gene Amphiregulin em células MCF7 e MDA-MB-231 via P13K /." Botucatu, 2014. http://hdl.handle.net/11449/123271.

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Orientador: Denise Fecchio
Coorientador: Célia Regina Nogueira
Banca: Selma Giorgio
Banca: Dulce Helena Jardim Costantino
Banca: Paula de Oliveira Montandon Hokama
Banca: Rozany Mucha Dofloth
Resumo: A importância do estrógeno (E2) no desenvolvimento do câncer de mama é bem estabelecido na literatura. O uso de antagonistas de E2 para o tratamento de tumores positivos para o receptor de estrógeno mostra-se importante para a sobrevida de pacientes acometidas pela doença. Amphiregulin (Areg), um fator de crescimento regulador multifuncional que pode ser induzido por estrógeno, possui papel central no desenvolvimento da glândula mamária e na morfogênese de órgãos e é expresso tanto em tecidos normais como cancerosos. Estudos clínicos sugerem que amphiregulin também desempenha papel importante na progressão do câncer da mama humano e a sua expressão aumentada tem sido associada com doença agressiva. Para investigar o mecanismo pelo qual o E2 induz a expressão de AREG, células MCF-7 e MDA-MB-231 foram tratadas durante 10 minutos, 30 minutos, 1 hora e 4 horas com veículo (controle) ou E2 isoladamente ou em associação com Fulvestrant (ICI, inibidor do receptor de estrógeno), Actinomicina D (ACTD, inibidor da transcrição gênica), Ciclohexamida (CHX, inibidor da síntese proteica) ou LY (inibidor da via PI3K). Os inibidores também foram utilizados isoladamente. O RNAm foi extraído das células pelo método de trizol e a expressão de AREG foi analisada por qRT-PCR. O tratamento de ambas as células com E2 induziu aumento do RNAm de AREG em todos os tempos analisados. Esse aumento foi parcialmente dependente de ER nas células MCF-7 nos tempos de 10 minutos, 1 e 4 horas. Em 30 minutos não foi observado a ligação do E2 com o ER para que houvesse o aumento da expressão do gene alvo. Nas células MDA-MB-231 o estrógeno aumentou o RNAm de AREG por pelo menos duas vias distintas em todos tempos analisados. Uma das vias ativa a via PI3K para que este efeito ocorra. Nossos resultados demonstram que o E2 é capaz de induzir a expressão de AREG em linhagens de células de câncer de ...
Abstract: The relevance of estrogen in breast cancer development is well established in the literature. The use of E2 antagonists for ER-positive breast cancer treatment is shown to be important to patients' survival. Amphiregulin, a multifunctional growth regulator factor that may be induced by estrogen plays a central role in development of mammary glands and organ morphogenesis, is expressed in both normal and cancerous tissues. Clinical studies suggest that amphiregulin also is important in human breast cancer progression and its expression has been associated with aggressive disease. To investigate the mechanism whereby E2 induces AREG expression, MCF-7 and MDA-MB-231 cells were treated for 10 minutes, 30 minutes, 1 hour or 4 hours with vehicle (control) or estrogen (E2) isolated or in association with Fulvestrant (ICI, estrogen receptor inhibitor), Actinomycin D (ACTD, gene transcription inhibitor), Cycloheximide (CHX, protein synthesis inhibitor ) or LY (PI3K inhibitor). The inhibitors were also used alone. mRNA was extracted from the cells by the Trizol method and AREG expression analyzed by qRT-PCR. Treatment of both cell types with E2 increased AREG mRNA expression at all moments. This increase was partially ER-dependent in MCF- 7 cells at 10 minutes, 1 and 4 hours. At 30 min, no binding of E2 to ER was obseved. In MDA-MB-231 cells, the estrogen-induced AREG mRNA was enhanced by two distinct pathways at the moments analyzed and PI3K pathways participated in one of them. Our results showed that E2 was able to induce the AREG expression in breast cancer cell lines in an ER-dependent and -independent manner
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Hammadi, Mehdi. "Implication du canal potassique hEag1 dans la migration des cellules épithéliales cancéreuses mammaires humaines MDA-MB-231." Amiens, 2012. http://www.theses.fr/2012AMIED005.

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Le cancer du sein, 1ère cause de mortalité par cancer chez la femme, est une maladie multifactorielle caractérisée par des phénomènes de prolifération, de migration et d’invasion. Ainsi, 75 % des cancers du sein sont canalaires infiltrants. Nos travaux portent plus particulièrement sur le canal potassique hEag1 (human Ether à go-go K+ channel 1). Ce canal est peu exprimé dans le tissu sain, à l’exception du cerveau, mais est surexprimé dans de nombreux cancers dont le cancer du sein. Dans cette étude, nous démontrons l’implication du canal hEag1 dans la migration des cellules cancéreuses épithéliales invasives mammaires humaines MDA-MB-231. En effet, nos travaux mettent en évidence deux modes de régulation de la migration de ces cellules par hEag1: une régulation indirecte, impliquant l’influx de Ca2+ par le canal calcique Orai1 et une régulation directe par interaction avec le complexe intégrines β1/FAK. Concernant l’implication des voies calciques dans la migration dépendante de hEag1, nos résultats démontrent que la dépolarisation du potentiel de membrane induite par l’inhibition du canal hEag1 s’accompagne d’une réduction de l’entrée basale de Ca2+ via le canal calcique Orai1. Ce couplage fonctionnel entre hEag1 et Orai1 est soutenu par une corrélation d’intensité des marquages immuno-histochimiques réalisés sur des tissus mammaires invasifs et des ganglions lymphatiques envahis associés. Concernant le lien entre la migration hEag1-dépendante et les complexes d’adhésion, nos résultats démontrent que le canal hEag1 interagit physiquement avec les intégrines β1 et les protéines FAK au niveau de radeaux lipidiques. Cette co-localisation de hEag1, des intégrines β1 et de Phospho-FAK se produit principalement au niveau du front de migration de la cellule. L’étude des voies de signalisation dépendantes de FAK démontre que l’inhibition du canal hEag1 diminue l’expression protéique des intégrines β1, la cinétique d’activation des FAK et l’expression de la GTPase RhoA. En conclusion, nos travaux démontrent que hEag1 est un acteur clé de la migration des cellules cancéreuses de sein, constituant à ce titre un marqueur diagnostic et/ou une cible thérapeutique potentiels de lutte contre les métastases
Breast cancer, the first cause of cancer death among women, is a multi-factorial disease characterized by proliferation, migration and invasion processes. 75 % of breast cancers are ductal invasive adenocarcinoma. Our study was focused on hEag1 K+ channel (human Ether à go-go K+ channel 1). HEag1 is overexpressed in several cancers including breast cancer, while its expression in normal tissues is more limited to the brain. In this study, we investigated the involvement of hEag1 in epithelial breast cancer cells MDA-MB-231 migration. We demonstrated that hEag1 regulated migration by two distinct pathways: (i) an indirect modulation by Orai1-dependant Ca2+ influx and (ii) a direct modulation by its interaction with integrins β1/FAK complex. Concerning the first pathway, our results demonstrated that hEag1 silencing induces membrane depolarization leading to a reduction of basal Ca2+ entry via Orai1 and therefore cell migration. Furthermore, hEag1 and Orai1 are co-localized in both breast invasive adenocarcinoma tissues and invaded lymph nodes. Concerning the second pathway, we showed that hEag1 physically interacts with integrins β1 and FAK proteins in lipids rafts. This co-localization occurs principally at the leading edge of the migrating cell. In addition, hEag1 silencing reduces integrins β1 expression, FAK activation and GTP-ase RhoA expression. To conclude, our works demonstrated, for the first time, that hEag1 is a key factor of breast cancer cell migration and lead us to take hEag1 into consideration as a potential novel marker and/or pharmaceutical target for the most aggressive human breast cancer

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Niese, Brandon A. "Fabrication of microfluidic devices to probe cell mechanical properties of MDA-MB-231 human breast cancer cells." Ohio University Honors Tutorial College / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ouhonors1556626033175996.

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Lin, Yi-Hsuan. "Zinc depletion induced apoptosis through Ca²⁺-dependent mitochondrial apoptotic pathway in human breast cancer MDA-MB-231 cells." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/43500.

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Breast cancer is the most frequently diagnosed cancer among Canadian women. Despite the use of advanced therapeutics, breast cancer remains the second leading cause of cancer death among Canadian women. Therefore, the development of novel and effective therapeutics to treat breast cancer remains an important goal. Defective or inhibited apoptosis is a major causative factor in the development and progression of cancer. Zinc is considered an apoptotic regulator. Further, previous work has also shown that there is an association between zinc depletion-induced apoptosis and an elevated intracellular Ca²⁺ level in human breast cancer MDA-MB-231 cells. Ca²⁺ is a known mediator of the mitochondrial apoptotic pathway. The overall objective of my thesis research was to investigate the role of intracellular Ca²⁺ and its involvement of the mitochondria in zinc depletion-induced apoptosis in human breast cancer MDA-MB-231 cells. MDA-MB-231 cells were cultured in DMEM containing FBS (10%) followed by depletion of intracellular zinc using N,N,N’,N’-tetrakis (2-pyridylmethyl) ethylenediamine (TPEN; 20 µM) with or without the presence of intracellular Ca²⁺ chelator, 1,2-bis (2-aminophenoxy) ethane-N,N,N’,N’-tetraacetic acid acetoxymethyl ester (BAPTA-AM; 10 or 20 µM). Apoptosis was assessed by caspase-9 and -3 activities using corresponding fluorogenic substrates and the proportion of cells with fragmented DNA using PI-staining flow cytometry assay. Intracellular Ca²⁺ was assessed using Fura-2 assay. Mitochondrial membrane potential was assessed by DiOC₆-staining flow cytometry assay. Cytochrome c release was detected by Western blot. Addition of TPEN resulted in an increase of caspase-9 and -3 activities, an increase in the proportion of cells with fragmented DNA, and a prolonged increase in intracellular Ca²⁺ level. TPEN treatment also reduced mitochondrial membrane potential and induced cytochrome c release. Zinc replenishment (10 – 40 µM) prevented TPEN-induced apoptosis. Intracellular Ca²⁺ chelation with BAPTA-AM suppressed TPEN-induced apoptosis, mitochondrial membrane potential loss, and cytochrome c release. Collectively these results showed that zinc depletion-induced apoptosis was mediated through the Ca²⁺-dependent mitochondrial apoptotic pathway in human breast cancer MDA-MB-231 cells.

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Bakker, Melinda. "Zinc depletion-induced apoptosis is associated with altered microRNA expression in human breast cancer MDA-MB-231 cells." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/45371.

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Bieber, Daniela [Verfasser], and Karl-Norbert [Akademischer Betreuer] Klotz. "Der A2B-Adenosinrezeptor und MAP-Kinase Aktivität in MDA-MB-231-Brustkrebszellen / Daniela Bieber. Betreuer: Karl-Norbert Klotz." Würzburg : Universitätsbibliothek der Universität Würzburg, 2011. http://d-nb.info/1016615140/34.

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Miller, Julia Anna [Verfasser], Ute [Akademischer Betreuer] Reuning, Ute [Gutachter] Reuning, and Percy A. [Gutachter] Knolle. "Tumorbiologische Effekte des Metastasierungssuppressors KAI1 und seiner Splice-Variante in humanen kultivierten MDA-MB-231- und MDA-MB-435-Zellen / Julia Anna Miller ; Gutachter: Ute Reuning, Percy A. Knolle ; Betreuer: Ute Reuning." München : Universitätsbibliothek der TU München, 2020. http://d-nb.info/1224046927/34.

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Hagood, Kendra, Keagan Davis Hackworth, Chukwunyere Ifeanyichukwu Umeh, Garret Mudd, Kristen Michaud, Morgan Cunningham, Ruben Torrenegra, and Victoria Palau. "The Cytotoxic Effects of Novel Flavonoids CT1 and CT3 on Breast Cancer Cells are Independent of the Presence of ER, PR, and HER2 Receptors." Digital Commons @ East Tennessee State University, 2021. https://dc.etsu.edu/asrf/2021/presentations/34.

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Introduction: Breast cancer is the most frequently diagnosed cancer found in women across the world, with an estimated 2.3 million new cases occurring in 2020. Additionally, over 684,000 deaths annually are attributed to breast cancer across the globe, making it the most common cause of cancer-related death in women. Further, treatment of breast cancer relies heavily on whether or not the cancer cells express estrogen, progesterone, and HER 2 receptors and this expression profile is often related to how quickly the cells grow and spread. In the United States, breast cancer cells that are hormone receptor positive and HER-2 negative make up about 73% of breast cancer cases, and cells that do not express any receptor and are known as triple negative, make up around 12% of cases (American Cancer Society, 2019). With that being said, CT1 and CT3 are novel compounds that have a cytotoxic effect on cell lines representing up to 85% of all breast cancer subtypes in the United States. Methods: The leaves of Chromolaena tacotana that contains the flavonoids CT1 and CT3 were dried and placed in a soxhlet extractor using dichloromethane (CH2Cl2) to extract the chlorophyll. The flavonoids were extracted using a column chromatography eluted with trichloromethane (CHCl3), a 1:1 dilution of CHCl3:methanol and methanol, followed by isolation and purification of the compounds. Human breast cancer cell lines MCF7, MDA-MB-231, and SKBr3 were treated with CT1 and CT3 at concentrations of 5, 10, 20, 40 and 80 µM, followed by incubation for 24 hours. To assess cell viability an MTT assay was conducted by adding a 5-diphenyl-tetrazolium bromide reagent. The purple-colored formazan crystals were solubilized with acidified isopropanol, then analyzed by spectrophotometry. Results: CT1 appeared to have the most cytotoxic effects compared to CT3 on MCF7. The opposite effect was observed for SKBr3 with CT3 showing the most effects as compared to CT1. No differential effect was observed on MDA-MB-231 since both CT1 and CT3 showed similar inhibition of cell viability. Conclusions: The results from the different breast cancer cell lines SKBr3, MCF7, and MDA-MB-231 vary based on how they responded to CT1 and CT3. CT3 was more effective on SKBr3 than CT1. CT1 was more effective on MCF7 than CT3. For MDA-MB-231, both CT1 and CT3 showed similar significant cytotoxic effects. The antiproliferative effects of CT1 and CT3 appear to be concentration dependent on all cells studied. In view of the results from MDA-MB-231 triple negative breast cancer cell line, the cytotoxic effect of the flavonoids is not dependent on the presence of estrogen, progesterone, or HER2 receptors on breast cancer cells. Further studies on the mechanism of action are necessary to elucidate the molecular targets of CT1 and CT3.

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Yang, Ming. "Functional involvement of voltage-gated Na+ channels in regulation of membrane potential in MDA-MB-231 human breast cancer cells." Thesis, University of York, 2015. http://etheses.whiterose.ac.uk/13094/.

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Voltage-gated Na+ channels (VGSCs) initiate and propagate action potentials in neurones. Functional VGSCs have been found in an increasing number of cancer cells and patient biopsies from different tissues. Blocking VGSCs using pharmacological agents or suppressing VGSC expression using RNA interference reduces cell metastatic behaviour, such as migration and invasion in vitro and metastasis in vivo in rodent models. In breast cancer, a high mRNA level of Nav1.5, a VGSC isoform, correlates with metastasis and poor prognosis. However, the detailed mechanism(s) underlying VGSC-dependent metastatic cell behaviours is not fully understood. Depolarised membrane potential (Vm) induces mitotic activity in neurones and causes tumourigenesis in Xenopus laevis. Given that VGSCs depolarise the Vm upon action potential firing in neurones, using MDA-MB-231 human breast cancer cells where VGSCs are endogenously expressed, the present study hypothesised that VGSCs increase cell metastatic behaviours by depolarising the Vm. This study found that VGSCs depolarise the Vm of MDA-MB-231 cells by ~4 mV. Hyperpolarising the Vm by blocking VGSCs with tetrodotoxin (TTX) or activating large conductance Ca2+-activated K+ channels using NS-1619 slowed cell migration to a similar extent. Rac1 is a small GTPase that potentiates cell migration via facilitating actin filament assembly. Both TTX and NS-1619 reduced the active Rac1 level at the leading edge of cells, suggesting that Vm controls Rac1 activity/distribution and henceforth cell motility in MDA-MB-231 cells. However, MDA-MB-231 cell invasion was inhibited by TTX but not NS-1619, suggesting that Na+, rather than Vm, may be the factor that underlies VGSC-dependent cell invasion. Finally, this study recorded Na+ current carried by VGSCs in tumour cells in tissue slices from mice, suggesting that VGSCs are functional in vivo. In summary, the present study provides novel evidence elucidating mechanisms underlying VGSC-dependent metastatic cell behaviours. Future experiments should explore VGSC/Vm as potential therapeutic targets in cancer treatment.

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Bellance, Catherine. "Impact des isoformes du récepteur de la progestérone sur la progression métastatique du cancer du sein : étude in vitro de la motilité de la lignée MDA-MB-231." Thesis, Paris 11, 2011. http://www.theses.fr/2011PA11T090.

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Le récepteur de la progestérone (PR) est un acteur majeur du développement de la glande mammaire. Dans les cellules épithéliales normales, PR est exprimé sous deux isoformes PRA (94 kDa) et PRB (116 kDa) de façon équimolaire. Il est établi que celles-ci ont un impact important sur le développement des cancers du sein, mais leurs rôles dans l’évolution métastatique reste très mal connus. Le ratio d’expression PRA/PRB étant souvent déséquilibré dans les tumeurs mammaires, nous avons analysé le turnover des deux isoformes. Nous avons démontré que PRA et PRB sont les cibles de modifications post-traductionnelles dirigées par les MAPK qui tendent à stabiliser l’une ou l’autre isoforme de manière sélective. Ainsi, Erk1/2 (p42/44) inhibe la dégradation de PRB tandis que la p38 stabilise PRA. Il en résulte que le ratio PRA/PRB varie de façon importante en fonction des signalisations extracellulaires impliquant les facteurs de croissance et les cytokines inflammatoires souvent exacerbés dans les cancers. Pour mieux étudier les effets différentiels de PRA et PRB, nous avons établi un modèle cellulaire original exprimant de manière bi-inductible l’une ou l’autre isoforme de PR, à partir de la lignée cellulaire MDA-MB 231 provenant d’une métastase de cancer du sein. En étudiant les variations induites par PRA ou PRB sur le transcriptome de ces cellules, nous avons identifié les gènes cibles spécifiques de ces isoformes. Parmi-eux se trouvent de nombreux gènes impliqués dans les cancers, notamment agissant sur la prolifération, la survie et la motilité cellulaires comme uPA et PAI-1. De plus, en analysant la migration cellulaire, nous avons mis en évidence un effet pro-migratoire de PRB particulièrement important en absence d’hormone. En recherchant la cause de ces effets, nous avons découvert que PRB était colocalisé et interagissait avec la kinase d’adhésion focale (FAK) qu’il active au niveau des points d’adhésion focaux. Ces travaux soulignent l’incidence du ratio PRA/PRB et du statut du ligand sur les métastases du cancer du sein, aussi bien au niveau de la sélectivité transcriptionnelle que celui des régulations non génomiques impactant la migration cellulaire. Nous suggérons la possibilité de cibler les tumeurs mammaires par des antagonistes sélectifs de PR et des inhibiteurs des voies de signalisation des MAPK ou de FAK
Progesterone receptor (PR) is a major actor of mammary gland development. PR is equally expressed as two main isoforms PRA (94 kDa) and PRB (116kDa) in the mammary gland epithelium. However, breast cancer progression has been associated with abnormalities of their expression ratio through undefined mechanisms. In this study, using a stably transfected cell line, we showed that PRA and PRB stabilizations are differentially regulated by Erk1/2 (p42/44) and p38 MAPKs respectively, leading to strongly influence PRA/PRB ratio. These results highlight the impact of growth factors and inflammatory cytokines on PRA/PRB imbalance in cancer cells. To study the differential effect of PR isoforms, we established an original bi-inducible cell line expressing either PRA and/or PRB. By analyzing variations induced by PRA and PRB on such cell transcriptomes, we identified the isoform-specific targets genes by DNA microarrays. Most of them are implicated in cancers, notably acting on cell proliferation, survival and motility. Furthermore, focusing our studies on cell migration, we showed that PRB acts as a pro-migratory factor particularly powerful in the absence of ligand. We discovered that PRB colocalized and interacted with the focal adhesion kinase (FAK) that was activated in focal adhesion points. Our results highlight the impacts of both PRA/PRB ratio and ligand status on metastatic evolution, in the contexts of transcriptional regulation as well as non-genomic events. We suggest the possibility to target mammary tumors by PR-selective antagonists and/or inhibitors of MAPK and FAK signalings

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Tshabalala, Malvin Thabani. "Investigation of non-prostatic in vitro prostate-specific membrane antigen expression in MCF-7 and MDA-MB-231 breast tumour cells." Diss., University of Pretoria, 2020. http://hdl.handle.net/2263/79132.

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Introduction Breast and prostate cancer mutually represent the most commonly occurring malignancies worldwide in women and men, respectively. The mutative state, recurrence capacity, resistance to conventional chemotherapy, low success rate of surgery and risks associated with radiotherapy confound the management of both these malignancies. There are several similarities between breast and prostate cancer, like growth hormone dependence and similar chemotherapeutic interventions. Therapy based on radiopharmaceuticals targeting the prostate-specific membrane antigen (PSMA) is proving to be a cutting-edge theranostics intervention for prostate cancer. Clinical positron emission tomography (PET) scans have located anti-PMSA binding sites in breast cancer in vivo. This indicates possible non-prostatic expression of PSMA, therefore research focused on understanding the cellular kinetics, PSMA expression profiles using two breast cancer adenocarcinoma cell lines as breast cancer models. This approach was to assess PSMA as a biomarker molecule that can aid in development of more selective, effective and safe diagnostic and therapeutic alternatives for breast cancer. This study was aimed at evaluating PSMA expression of MCF-7 or MDA-MB-231 mammary adenocarcinoma cell lines in comparison to a known high PSMA expressing LNCaP prostate carcinoma and EA.hy926 hybrid vascular endothelial cell line. Methods In vitro cultures of LNCaP’s , a prostatic adenocarcinoma cell line, MCF-7 and MDA-MB-231 breast adenocarcinoma cell lines and endothelial EA.hy926 cells were tested for expression of PSMA by flow cytometry. The LNCaP cells were used a positive control. Cellular localisation of PSMA was achieved utilising confocal microscopy and fluorescently-tagged antibodies in all the cell lines tested. PSMA was quantified in all the cell lines utilising ELISA. Prior to experimentation, a pilot study was undertaken to optimise cell detachment methods. Trypsinisation was compared to mechanical scraping to evaluate a cell detachment method that allowed optimal downline experimentation. Results Findings from three supporting and complementary techniques demonstrate positive PSMA identification, localisation and quantification in all the probed cell lines despite three cell types not having a prostrate origin. Quantitatively, LNCaP cells reported the highest concentration of PSMA followed by the malignant MDA-MB-231 cells, then the MCF-7 cell line and least in EA.hy926 cells. The difference in fluorescence between LNCaP cells and all three investigational cell lines was statistically significant however the difference in fluorescence between the three investigational cell lines was not statistically significant. The PSMA antigen was localised on the cell membrane and diffused within the cytosol in LNCaP cells. The MDA-MB-231, MCF-7 and EA.hy926 cells all exhibited a differential expression pattern of PSMA. These cells showed diffuse cytosolic accumulation and intense circular region accumulation apparently bordering the cell membrane and the cell nucleus. The quantification of PSMA reported the highest concentration as being in LNCaP cells. The MDA-MB-231 cells were second, then the MCF-7 cells and the lowest concentration. Significant differences were seen between the positive control and the investigation cell lines. The difference in concentration between the investigational cell lines was not significant. Finally, cryotome sections of biopsies of tumours from two breast cancer patients were found to show detectable PSMA presence. Discussion Fluorescence is directly proportional to concentration. The high fluorescence of PSMA exhibited by LNCaP cells in the flow cytometry results can be equated to concentration. A fundamental point of departure from which PSMA expression in the breast carcinoma cell lines could be investigated was established. Expression of PSMA is associated with cancer aggression, metastatic progression and increased malignancy. These clinicopathological characteristics support the expression of PSMA seen in MDA-MB-231. Contrastingly, the same characteristics aren’t seen in MCF-7 cells but expression of PSMA was observed. The expression is not entirely dismissible as other luminal A cell lines have also been shown to express PSMA. The EA.hy926 cells are somatic hybrids that are made up of lung A549 cells and HUVEC’s. Lung cancer has been shown to also express PSMA when probed utilising histology. The expression of PSMA in EA.hy926 is the first of its kind but may be attributable to its lung carcinoma makeup. The pattern of expression in the LNCaP confocal microscopy images can be expected. The PSMA antigen is a transmembrane receptor and as such intense fluorescence was seen on the membrane. Expression of PSMA in the cytoplasm has been reported and was equally observed in the LNCaP cells. The investigation cell line showed accumulation of green fluorescence in vesicular bodies bordering the cell membrane and in juxtanuclear positions. The expression of PSMA has been reported in the mitochondria and the green fluorescence at the nucleus could be mitochondrial. The Golgi apparatus and endoplasmic reticulum have also been recognised as potential location of PSMA expression. The localisation of both these organelles at the nucleus along with the expression of PSMA seen close to the nucleus could be associated. Worth noting is the internalisation properties of PSMA. The antigen has an internalisation signal that can be induced by ligand binding or in the absence of a ligand. Upon internalisation the receptors are vesicled and transported either for degradation of for recycling. The vesicular expression seen close to the membrane in the investigational cell lines could be PSMA that is being trafficked for recycling or degradation upon internalisation. The ELISA quantification revealed the levels of PSMA in the positive control are 100-fold greater than those in the investigation cell lines. The ability to translate PSMA targeting in clinical settings is questionable when considering the difference in concentration values. The probing of PSMA in histological slices was positive and showed patterns that are similar to those seen in the monolayer cultures. This shows continuity between two-dimensional cultures and heterogeneous tissue samples. The premise for investigation of PSMA as a potential theranostic target was established through positive identification, localisation and quantification across three independents methods. Conclusion This study is the first of its kind to report reproducible expression of PSMA in the two-dimensional cultures of breast adenocarcinoma MDA-MB-231 and MCF-7 cell lines as well as in the hybrid endothelial EA.hy926 cell line. The results were confirmed by three different techniques where different antibodies were used for the ELISA showing reproducibility in the findings. Moreover, the generated results support the apparent localisation of PSMA in breast cancer patients utilising PSMA targeting radionuclides in PET imaging in a clinical setting. The potential application of this study’s result is stimulating. The success being realised in prostate cancer theranostics through PSMA targeting, may conceivably be realised in other carcinomas, particularly breast carcinoma theranostics.
Dissertation (MSc)--University of Pretoria, 2020.
https://doi.org/10.25403/UPresearchdata.14885454
Pharmacology
MSc
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Klipfel, Laurence. "Implication des septines recrutées sur les microtubules tyrosinés et polyglutamylés dans la résistance au taxol de cellules cancéreuses mammaires MDA-MB 231." Phd thesis, Université Paris Sud - Paris XI, 2011. http://tel.archives-ouvertes.fr/tel-00656975.

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Le cancer du sein est une cause importante de mortalité féminine en France et l'émergence de chimiorésistance, en particulier avec les taxanes, dont le paclitaxel (Taxol®), est une limite importante à l'emploi de ces molécules. Comme de nombreux anticancéreux, les taxanes ciblent les microtubules (MTs), des polymères de tubuline intervenant dans de nombreuses fonctions cellulaires. Ces derniers alternent entre des phases de croissance et de désassemblage, leur conférant ainsi un caractère dynamique. En se liant à la beta-tubuline, le Taxol stabilise les MTs et bloque la mitose, conduisant la cellule vers l'apoptose. La résistance au Taxol est un processus multifactoriel impliquant des mécanismes tels que la surexpression de pompes d'efflux (P-glycoprotéine), des mutations des gènes d'alpha- et de beta-tubuline ou une expression altérée de protéines associées aux MTs (MAPs) telles que MAP4 (stabilisatrice des MTs) ou la stathmine (dépolymérisante), contribuant ainsi à la restauration de la dynamique microtubulaire.Le projet repose sur l'emploi de la lignée tumorale mammaire MDA-MB 231 rendue résistante par paliers à 25nM de Taxol dans des conditions de blocage des pompes d'efflux. L'objectif étant d'explorer les variations protéiques de l'environnement des MTs associées au phénotype chimiorésistant, nous avons comparé le protéome d'extraits microtubulaires de cellules sensibles (Tv) et résistantes au Taxol (T8). Parmi les 112 protéines statistiquement enrichies dans une des deux populations de MTs, on retrouve notamment une augmentation des tubulines beta III et IV, une augmentation et une diminution respectives des moteurs moléculaires kinésine-1 et dynéine ainsi que l'enrichissement de plusieurs septines (SEPT2, 8, 9 et 11) dans les fractions de MTs T8. Les septines sont des GTPases associées en complexes hétéro-oligomériques impliquées dans la cytocinèse et l'organisation du cytosquelette de MTs et d'actine. Le recrutement de ces protéines candidates sur les MTs des cellules T8 a été validé par Western blot (Froidevaux-Klipfel et al., 2011) et immunofluorescence. Dans la littérature, les septines sont décrites comme étant localisées soit au niveau de l'actine soit au niveau des MTs dans les cellules de mammifères. De façon intéressante, dans nos cellules MDA-MB 231, nous observons un recrutement partiel de SEPT2 sur les fibres d'actine dans les cellules Tv alors qu'elle colocalise avec les MTs des cellules T8. Bien que la dépolymérisation de l'actine dans les cellules Tv n'entraine aucun déplacement des septines vers les MTs, cette localisation différentielle des septines sur les MTs des cellules résistantes pourrait néanmoins participer au phénotype chimiorésistant.Par ailleurs, il a été décrit dans la littérature que SEPT2 se lie aux MTs polyglutamylés afin de faciliter le transport vésiculaire à la membrane de protéines impliquées dans la polarisation cellulaire. La polyglutamylation est une modification post-traductionnelle permettant la formation de chaines latérales d'un à plusieurs résidus glutamate sur les tubulines alpha ou beta, régulant ainsi les interactions entre MTs et MAPs. Nos résultats montrent que l'accumulation des septines sur le réseau de MTs des cellules T8 s'accompagne d'une augmentation de la polyglutamylation mais aussi de la tyrosination de la tubuline. De plus, des tests de viabilité cellulaire ont mis en évidence que l'inhibition partielle par RNAi des septines ainsi que des polyglutamylases et de la tubuline tyrosine ligase, comme la surexpression d'enzymes responsables de la déglutamylation de la tubuline, permettent de restaurer une certaine sensibilité au Taxol des cellules T8. Inversement, la surexpression de certaines enzymes responsables de la polyglutamylation et de la tyrosination de la tubuline dans les cellules Tv permet d'instaurer une résistance au Taxol des cellules sensibles.La compilation de nos résultats permet de proposer un nouveau mécanisme de résistance au Taxol des cellules cancéreuses mammaires MDA-MB 231 : une augmentation du niveau de tyrosination de l'alpha-tubuline serait à l'origine de l'allongement des chaînes polyglutamylées sur le MT entraînant une diminution de la liaison de la protéine stabilisatrice MAP4 ainsi que le recrutement des septines sur les MTs. Ces modifications favoriseraient alors le recrutement du facteur de sauvetage CLIP-170 et de kinésines dépolymérisantes telles que MCAK à l'extrémité en croissance du MT des cellules résistantes T8, permettant une certaine restauration de la dynamique microtubulaire et contribuant ainsi à l'apparition du phénotype chimiorésistant.Ces études sont indispensables pour établir les bases d'un nouveau mécanisme de résistance au Taxol impliquant les septines, ainsi qu'un lien de causalité avec la tyrosination et la polyglutamylation. Au-delà, la recherche de ces modulations clés pourra être réalisée sur des cancers mammaires sensibles et résistants au Taxol, issus de biopsies de patients. Ainsi, il sera possible à terme, de déterminer si les septines, la tyrosination et la polyglutamylation de la tubuline ont une véritable importance fonctionnelle dans la résistance de cancers du sein au Taxol.

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23

Hisarli, Nazli Deniz. "The Effect Of Salvia Absconditiflora Extract On The Gene Expressions Of Gsto1 And Gstz1 In Mcf-7 And Mda-mb-231 Cells." Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615520/index.pdf.

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S.absconditiflora is one of the endemic Salvia species grown in Turkey, which is consumed as a herbal tea. Because of the presence of high amounts of vesicles on their leaves, S.absconditiflora is very rich in active compounds. S.absconditiflora water extract was investigated for its antioxidant capacity by 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay. Total phenolic and total flavonoid contents were quantified by spectrophotometric methods. LC-MS/MS analyses revealed the presence and quantities of caffeic acid, luteolin rutin and coumaric acid. Cytotoxic effects of water extract of S.absconditiflora on breast cancer cell lines (MCF-7 and MDA-MB-231) were examined via XTT colorimetric assay and Trypan Dye Exclusion cell viability assay. IC50 values for each cell line at 24 and 48 hours were determined. The results indicated that water extract of leaves of S.absconditiflora could inhibit cell proliferation in MCF-7 and MDA-231 cells in dose dependent but not in time dependent manner. Effects of S.absconditiflora water extract on the expression of glutathione-S-transferases (GSTs) in MCF-7 and MDA-MB-231 cells were investigated with qRT-PCR technique. IC50 values calculated in XTT experiment for 24h incubation was used as cytotoxic extract concentration. It was found that treatment of MCF-7 cells with 1,558 mg/ml of extract enhanced an increase in expression as 2 and 2,8 fold in GSTO1 and GSTZ1 genes, respectively. Treatment of MDA-MB-231 cells with 1,131 mg/ml of extract resulted in 1,57 fold increase for GSTO1 and 1,56 fold increase for GSTZ1.

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Kozina, Vladimir Joseph. "Induction and characterization of de novo methylation by benzo[A]pyrene in the cancer cell lines MCF-7 and MDA-MB-231." Scholarly Commons, 2005. https://scholarlycommons.pacific.edu/uop_etds/609.

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The experiments presented were designed to test the hypothesis that the well-known carcinogen, benzo[a]pyrene has epigenetic effects, specifically the ability to alter cytosine methylation patterns. MCF-7 and MDA-MB-231 human breast cancer cells were treated for a period of sixty days with 100 nM benzo[a]pyrene. The methylation status of two genes, Ecadherin and GSTP 1 were examined using methyl-specific PCR and Southern blot analysis. After sixty days, no detectable change in methylation was observed. Evidence exists that de novo methylation is a consequence of transcriptional inactivity. Benzo[a]pyrene can contribute to transcriptional repression by sequestering the transcription factor, Spl. To test this hypothesis in our system, MCF-7 cells were transiently transfected with a reporter construct containing Sp 1 sites. These experiments demonstrated an 8.4 fold increase in reporter gene activity over a promoterless control plasmid; however, a difference could not be established between benzo[a]pyrene-treated and untreated cells.

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Froidevaux-Klipfel, Laurence. "Implication des septines recrutées sur les microtubules tyrosinés et polyglutamylés dans la résistance au taxol de cellules cancéreuses mammaires MDA-MB 231." Thesis, Paris 11, 2011. http://www.theses.fr/2011PA114850/document.

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Le cancer du sein est une cause importante de mortalité féminine en France et l’émergence de chimiorésistance, en particulier avec les taxanes, dont le paclitaxel (Taxol®), est une limite importante à l’emploi de ces molécules. Comme de nombreux anticancéreux, les taxanes ciblent les microtubules (MTs), des polymères de tubuline intervenant dans de nombreuses fonctions cellulaires. Ces derniers alternent entre des phases de croissance et de désassemblage, leur conférant ainsi un caractère dynamique. En se liant à la beta-tubuline, le Taxol stabilise les MTs et bloque la mitose, conduisant la cellule vers l’apoptose. La résistance au Taxol est un processus multifactoriel impliquant des mécanismes tels que la surexpression de pompes d’efflux (P-glycoprotéine), des mutations des gènes d’alpha- et de beta-tubuline ou une expression altérée de protéines associées aux MTs (MAPs) telles que MAP4 (stabilisatrice des MTs) ou la stathmine (dépolymérisante), contribuant ainsi à la restauration de la dynamique microtubulaire.Le projet repose sur l’emploi de la lignée tumorale mammaire MDA-MB 231 rendue résistante par paliers à 25nM de Taxol dans des conditions de blocage des pompes d’efflux. L’objectif étant d’explorer les variations protéiques de l’environnement des MTs associées au phénotype chimiorésistant, nous avons comparé le protéome d’extraits microtubulaires de cellules sensibles (Tv) et résistantes au Taxol (T8). Parmi les 112 protéines statistiquement enrichies dans une des deux populations de MTs, on retrouve notamment une augmentation des tubulines beta III et IV, une augmentation et une diminution respectives des moteurs moléculaires kinésine-1 et dynéine ainsi que l’enrichissement de plusieurs septines (SEPT2, 8, 9 et 11) dans les fractions de MTs T8. Les septines sont des GTPases associées en complexes hétéro-oligomériques impliquées dans la cytocinèse et l’organisation du cytosquelette de MTs et d’actine. Le recrutement de ces protéines candidates sur les MTs des cellules T8 a été validé par Western blot (Froidevaux-Klipfel et al., 2011) et immunofluorescence. Dans la littérature, les septines sont décrites comme étant localisées soit au niveau de l’actine soit au niveau des MTs dans les cellules de mammifères. De façon intéressante, dans nos cellules MDA-MB 231, nous observons un recrutement partiel de SEPT2 sur les fibres d’actine dans les cellules Tv alors qu’elle colocalise avec les MTs des cellules T8. Bien que la dépolymérisation de l’actine dans les cellules Tv n’entraine aucun déplacement des septines vers les MTs, cette localisation différentielle des septines sur les MTs des cellules résistantes pourrait néanmoins participer au phénotype chimiorésistant.Par ailleurs, il a été décrit dans la littérature que SEPT2 se lie aux MTs polyglutamylés afin de faciliter le transport vésiculaire à la membrane de protéines impliquées dans la polarisation cellulaire. La polyglutamylation est une modification post-traductionnelle permettant la formation de chaines latérales d’un à plusieurs résidus glutamate sur les tubulines alpha ou beta, régulant ainsi les interactions entre MTs et MAPs. Nos résultats montrent que l’accumulation des septines sur le réseau de MTs des cellules T8 s’accompagne d’une augmentation de la polyglutamylation mais aussi de la tyrosination de la tubuline. De plus, des tests de viabilité cellulaire ont mis en évidence que l’inhibition partielle par RNAi des septines ainsi que des polyglutamylases et de la tubuline tyrosine ligase, comme la surexpression d’enzymes responsables de la déglutamylation de la tubuline, permettent de restaurer une certaine sensibilité au Taxol des cellules T8. Inversement, la surexpression de certaines enzymes responsables de la polyglutamylation et de la tyrosination de la tubuline dans les cellules Tv permet d’instaurer une résistance au Taxol des cellules sensibles.La compilation de nos résultats permet de proposer un nouveau mécanisme de résistance au Taxol des cellules cancéreuses mammaires MDA-MB 231 : une augmentation du niveau de tyrosination de l’alpha-tubuline serait à l’origine de l’allongement des chaînes polyglutamylées sur le MT entraînant une diminution de la liaison de la protéine stabilisatrice MAP4 ainsi que le recrutement des septines sur les MTs. Ces modifications favoriseraient alors le recrutement du facteur de sauvetage CLIP-170 et de kinésines dépolymérisantes telles que MCAK à l’extrémité en croissance du MT des cellules résistantes T8, permettant une certaine restauration de la dynamique microtubulaire et contribuant ainsi à l’apparition du phénotype chimiorésistant.Ces études sont indispensables pour établir les bases d’un nouveau mécanisme de résistance au Taxol impliquant les septines, ainsi qu’un lien de causalité avec la tyrosination et la polyglutamylation. Au-delà, la recherche de ces modulations clés pourra être réalisée sur des cancers mammaires sensibles et résistants au Taxol, issus de biopsies de patients. Ainsi, il sera possible à terme, de déterminer si les septines, la tyrosination et la polyglutamylation de la tubuline ont une véritable importance fonctionnelle dans la résistance de cancers du sein au Taxol
Breast cancer remains the leading cause of women mortality in France, and chemoresistance emergence, in particular to taxanes, including paclitaxel (Taxol®), is an important limitation to the use of these molecules. As do many anticancer drugs, taxanes target microtubules (MTs), tubulin polymers involved in many cellular functions. These alternate between growing and shrinking stages, thus providing dynamic instability. By binding to beta-tubulin, Taxol stabilizes MTs and prevents successful mitosis, leading to apoptosis. Taxol resistance is a multifactorial process including mechanisms such as overexpression of drug efflux pumps (P-glycoprotein), mutations in the genes for alpha- and beta-tubulin or altered expression of MT-associated proteins (MAPs) like the MT-stabilizing MAP4 or the depolymerizing stathmin, therefore contributing to MT dynamics restoration.The current project relies on the use of the breast carcinoma cell line MDA-MB 231 made gradually resistant to 25nM of Taxol under blocking conditions of efflux pumps. To get a broader insight into the protein modifications from the MT environment associated with the chemoresistant phenotype, we compared the proteomic profiles of total MT fractions from Taxol-sensitive (Tv) and Taxol-resistant (T8) cells. Among the 112 differentially enriched proteins found in one of the two populations, we evidenced increased levels of betaIII and betaIV-tubulins, a slight increase and a decrease of molecular motors kinesin-1 and dynein, respectively, and the enrichment of several septins (SEPT2, 8, 9 and 11) in MT fractions of T8 cells. Septins are GTPases that associate into hetero-oligomeric complexes involved in cytokinesis and in MT and actin cytoskeleton organization. Recruitment of these candidate proteins on MTs of T8 cells has been validated by Western blot analysis (Froidevaux-Klipfel et al., 2011) and immunofluorescence experiments.In the literature, septins localize either on actin or MTs in mammalian cells. Interestingly, in our MDA-MB 231 cells, SEPT2 is recruited partially on actin stress fibers in sensitive Tv cells, whereas it colocalizes with MTs in T8 ones. Although actin depolymerization in Tv cells does not induce any shift towards MTs, this differential localization of septins on MTs of resistant cells could nevertheless participate in the chemoresistant phenotype.Furthermore, it has been described in the literature that SEPT2 binds to polyglutamylated MTs to facilitate vesicular transport to the plasma membrane of proteins implicated in cell polarization. Polyglutamylation is a post-translational modification allowing the formation of side-chains of several glutamate residues on alpha- or beta-tubulins, thus regulating interactions between MTs and MAPs. Our results show that septin accumulation on the MT network of T8 cells is associated with an increase in polyglutamylation but also tyrosination of tubulin. In addition, cell viability assays showed that partial inhibition by RNAi of septins as well as polyglutamylases and tubulin tyrosine-ligase, but also overexpression of enzymes responsible for tubulin deglutamylation, could restore Taxol sensitivity of T8 cells. By contrast, overexpression of enzymes responsible for tubulin polyglutamylation and tyrosination in Tv cells could induce Taxol resistance of sensitive Tv cells.The compilation of our results enables us to provide a new mechanism of Taxol resistance of the breast cancer cells MDA-MB 231: an increased level of alpha-tubulin tyrosination would induce the lengthening of polyglutamylated chains on the MT, resulting in a reduced binding of the stabilizing protein MAP4 as well as the recruitment of septins on MTs. These modifications would promote the recruitment of the rescue factor CLIP-170 and that of depolymerizing kinesins such as MCAK to the growing end of the MT of resistant T8 cells, leading to a restoration of MT dynamics, thus contributing to the emergence of the chemoresistant phenotype.These studies are essential to lay the basis for a new mechanism of Taxol resistance involving septins, and a causal relationship to tyrosination and polyglutamylation. Beyond, the search for these key modulations will be performed on Taxol sensitive and resistant breast cancers, from patients’ biopsies. Thus, it will be eventually possible to determine whether septins, tubulin tyrosination and polyglutamylation have a real functional importance in breast cancer resistance to Taxol

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Pham, Hoang Son. "Membrane Heparan Sulfate Proteoglycans in the breast cancer microenvironment." Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/212715/1/Hoang%20Son_Pham_Thesis.pdf.

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This project investigated the role of the cellular microenvironment in regulating human breast cancer (BC) models by examining members of the Heparan Sulfate Proteoglycan (HSPG) family of glycoproteins. Small interfering RNAs were used to in vitro to inhibit HSPG gene expression and examine effects on target gene expression, cell proliferation and cell migration in BC cell lines. Findings suggested HSPGs (i.e., Sydencan 1/4, SDC1/4) promote BC proliferation via Akt/Wnt signalling and also influence BC cell migration. As such the SDC1/4 HSPGs can be considered as potential biomarkers for the early diagnosis and treatment of BC.

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López, Linares Rodolfo. "Análisis de la expresión génica de receptores de leptina, en líneas celulares de cáncer de mama, MCF7, MDA-MB 231 y HCC1937 empleando estándares de leptina y tamoxifeno." Tesis de maestría, Universidad Autónoma del Estado de México, 2019. http://hdl.handle.net/20.500.11799/104782.

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Trabajo de investigación en líneas celulares de cáncer de mama en módelo de obesidad y su expresión de Receptor de leptina con diferentes concentraciones de tamoxifeno
Introducción El cáncer de mama es el principal tipo de cáncer que afecta a las mujeres a nivel mundial; es una patología que se puede desencadenar debido a múltiples factores que conllevan a una proliferación anormal y descontrolada de células que componen la glándula mamaria. Uno de los factores que ha incrementado la incidencia y presenta peor pronóstico de este tipo de cáncer es la obesidad. En esta condición son secretadas altas cantidades leptina, una proteína que presenta actividad proliferativa, mitogénica, antiapoptótica y proinflamatoria que puede resultar antagónica al tratamiento quimioterapéutico. Objetivo: El objetivo del proyecto fue identificar la modulación de la expresión génica de receptores de leptina y la proliferación celular en líneas celulares de cáncer de mama (MDA-MB 231, MCF-7 y HCC1937) como resultado de su estimulación con leptina y tamoxifeno y establecer un modelo de abordaje inicial para el estudio de los subtipos de cáncer de mama y su comportamiento a la respuesta de la acción de las adipocinas y su posible relación con el mecanismo de resistencia a quimioterapéuticos como el tamoxifeno en líneas celulares ER positivo y triple marcador negativo Material y métodos: Se realizó la evaluación de la modulación de la expresión del receptor de leptina en presencia de estímulos de leptina y tamoxifeno en las líneas celulares de cáncer de mama MCF 7, MDA MB 231 y HCC 1937 mediante ensayos de proliferación con tinción de cristal violeta, y análisis de la expresión de mRNA del receptor de leptina mediante su transcripción a cDNA, PCR en punto final y RT-PCR, así mismo se evaluó la expresión de la proteína del receptor de leptina mediante ELISA. Resultados: Se determinó que la leptina es capaz de modular positivamente la proliferación de las tres líneas celulares de cáncer de mamá y el tamoxifeno es capaz de ejercer un efecto antiproliferativo en las mismas, se identificó que la capacidad del tamoxifeno para disminuir la proliferación de células cancerígenas se ve disminuida en presencia de leptina, aunada a cambios en la modulación de la expresión de su receptor. Del mismo modo se determinó la concentración de la proteína de ObR mediante la técnica de ELISA obteniéndose una mayor concentración en todos los casos en comparación con el control, no obstante la variación no es estadísticamente significativa. Conclusiones: El tamoxifeno es un agente quimioterapéutico capaz de inducir una mayor modulación de la expresión del ObRb en las líneas celulares de cáncer de mama, lo cual puede estar relacionado con la disminución de su actividad antiproliferativa, mientras que la leptina genera un efecto proliferativo en las tres líneas celulares, lo cual corresponde con los reportes de su actividad proliferativa, antiapoptótica y mitogénica.
SEIA- UAEMéx 4563-2018 CIV

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Alreemi, Roaa. "Chemical and Biological Studies of Hibbertia Scandens (Snake Vine)." Thesis, University of Sydney, 2020. https://hdl.handle.net/2123/23515.

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The First Australian Community is one of the ancient civilizations which depended upon the available surrounding natural resources for their clothing, nutrition and healing of disease. Unfortunately, some of their traditional medicines and / or their practical applications are lost because of poor written documentation. Plants form parts of ancient remedies used by Aboriginal and Torres Strait Islander peoples to heal ailments due to their antibacterial and antiviral activities. One of these medicinal plants is Hibbertia Scandens (Snake Vine), which was used in Aboriginal Communities’ traditional medicines to treat sores and rashes. In the current study, the leaves and roots of H. scandens were extracted using solvents ranging from less polar to more polar, and these extracts were chemically profiled by HPLC and LCMS. The bioactivity of these extracts was tested against the MCF-7 breast cancer cell line using the MTT assay; four extracts of the eight showed cytotoxic activity against MCF-7, with GI50 less than 100 μg/mL after 48 hours incubation. The DCM extract from the plant roots exhibited the greatest growth inhibition potential, with the lowest GI50 (45.7 μg/mL) after treatment for 48 hours. This extract was chosen for further studies and was further separated into twelve fractions using semi-preparative HPLC; the bioactive fractions were identified by an MTT cytotoxic analysis, with four fractions (8, 9, 10 and 12) showing an anti-proliferative effect. Fraction 8 was identified as β-sitosterol (14) and fraction 12 as β-sitosterol glucoside (18) using spectroscopic techniques. β-Sitosterol was chosen for further semi-synthetic studies as it is has known anticancer activity. Seven derivatives were produced, six of which are novel analogues and their characterization was performed using several spectroscopic techniques, including 2D NMR, FT-IR, LRMS and HRMS. The growth inhibition potential of all of these derivatives was tested against two breast cancer cell lines (MCF-7 and MDA-MB-231). β-Sitosterol and four of its derivatives showed cytotoxic effects against MCF-7, while the growth of the other cell line (MDA-MB-231) was only affected by one derivative. The tetrazole (25) analogue was the most active derivative, with increased growth inhibitory activity against both breast cancer cell lines over the corresponding carboxylic acid analogue (GI50 10.67 μM against MCF-7 and 16.27 μM against MDA-MB-231). This analogue arrests both breast cancer cell lines in the G2/M phase after 72h of treatment with GI50 and GI50 × 2 concentrations, suggesting that it acts upon mitotic division.

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Da, Silva Liberio Michelle. "Chemical and Biological Investigations of Anticancer Compounds from Australian Ascidians." Thesis, Griffith University, 2014. http://hdl.handle.net/10072/365813.

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Nature is the main source of anticancer agents with about 60% of the current anticancer drugs originating in some way from natural products. Many cytotoxic natural products have been isolated from marine invertebrates. One group of marine animals that have made significant contributions is the tunicates or ascidians. Ascidians belonging to the family Didemnidae are known to be a prolific and rich source of new chemical entities with biological activity. This study was divided into two main components. In the first part, Didemnid ascidians collected from the Great Barrier Reef (GBR) were investigated for their chemical diversity using spectroscopic and spectrometric techniques. In part two, an ascidian drug discovery screening library was generated and subsequently used to identify cytotoxic or cytostatic compounds in prostate (LNCaP) and breast (MDA-MB-231) cancer cells. The ascidian natural products isolated in part 1 were all tested in these cancer cell lines. Moreover, one of the cytotoxic compounds identified from the screening studies was subjected to mechanism of action studies.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Biomolecular and Physical Sciences
Science, Environment, Engineering and Technology
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Machado, Kaliana Larissa. "Estresse oxidativo na ação da cafeína sobre a proliferação e morte de células de câncer de mama MCF-7 e MDA-MB-231." Universidade Estadual de Londrina. Centro de Ciências Biológicas. Programa de Pós-Graduação em Patologia Experimental, 2015. http://www.bibliotecadigital.uel.br/document/?code=vtls000215273.

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O câncer de mama é a neoplasia com maior taxa de mortalidade entre as mulheres no mundo todo. A cafeína é uma substância consumida mundialmente e vem sendo muito estudada devido à sua capacidade de induzir apoptose em células tumorais, porém os mecanismos pelos quais age sobre células de câncer de mama ainda não foram totalmente esclarecidos. Portanto, os objetivos desse trabalho foram verificar a participação do estresse oxidativo na ação da cafeína sobre a proliferação e morte de células de câncer de mama MCF-7 e MDA-MB-231, analisando se a cafeína altera a viabilidade e proliferação celular e se ocorre alteração do estado oxidativo, correlacionando essa alteração com a presença ou não de lesão de DNA e alteração da taxa de apoptose celular. Para isso as duas linhagens foram tratadas com quatro concentrações de cafeína (1,0; 2,5; 5,0 e 10mM) e em seguida foram avaliadas a viabilidade, proliferação e os padrões de morte celular. Também foram analisados os parâmetros de estresse oxidativo através dos níveis de lipoperóxidos de membrana, malondialdeído e tióis totais e o efeito da cafeína no material genético das células através dos níveis de 8-hidroxi-2-deoxiguanosina e teste do cometa. Para avaliar a participação do estresse oxidativo na citotoxicidade da cafeína o teste do brometo de 3-[4,5-dimetil-tiazol-2-il]-2,5-difeniltetrazólio (MTT) foi realizado após o tratamento com 10mM de cafeína na ausência e presença de sequestradores de espécies reativas de oxigênio (ERO) específicos histidina, superóxido dismutase e trolox para sequestro de oxigênio singlete, ânion radical superóxido e radical peroxil, respectivamente. Os resultados demonstraram que a cafeína apresenta efeito citotóxico em células de mama tumorais, sendo observado, nas concentrações mais elevadas (5 e 10mM), indução de apoptose e necrose. Esse efeito parece estar relacionado com seu potencial de indução de estresse oxidativo e dano ao DNA. Reações distintas entre as linhagens celulares frente ao tratamento com cafeína foram observadas, verificando uma maior resistência das células MCF-7. Esses resultados ajudam a entender os mecanismos de ação da cafeína sobre células de câncer de mama e sugerem que seu uso possa ser eficaz como adjuvante no tratamento do câncer de mama.
Breast cancer is the neoplasia with the highest mortality rate among women worldwide. Caffeine is a substance consumed worldwide and has been extensively studied because of its ability to induce apoptosis in tumor cells, but the mechanisms by which acts on breast cancer cells have not yet been fully clarified. Therefore, the objectives of this study were to verify the involvement of oxidative stress in the action of caffeine on the proliferation and death of breast cancer cells MCF-7 and MDA-MB-231, analyzing if caffeine alters the viability and cell proliferation, the occurrence of oxidative stress and whether this could be associated with alterations in DNA and apoptosis rate injury. For this the two lines cells were treated with four concentrations of caffeine (1.0, 2.5, 5.0 and 10mM) and analyzed for several parameters indicative of the oxidative state, including membrane lipoperoxide levels, malondialdehyde and total thiol contents as well as effect of caffeine in the genetic material of cells, by measuring levels of 8-hydroxy-2-deoxyguanosine and comet assay. The viability, proliferation and cell death patterns were also evaluated. To evaluate the role of oxidative stress in caffeine cytotoxicity the MTT test was performed after treatment with caffeine (10mM) in the absence and presence of scavengers of reactive oxygen species (ROS) specific: histidine, superoxide dismutase and trolox. The results demonstrated that caffeine has a cytotoxic effect on breast tumor cells and, at highest concentrations (5 and 10mM), apoptosis and necrosis induction. This effect seems to be related to its potential for oxidative stress and DNA damage induction. Different behaviors among cell lines before the caffeine treatment were observed checking a greater resistance of MCF-7 cells. These results help to understand the caffeine mechanisms of action on breast cancer cells and suggest that its use can be effective as an adjuvant therapy for breast cancer.

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Karimian, Negin [Verfasser]. "A novel role of CDK5 in tumor growth, migration and proliferation of breast cancer cell lines MDA-MB-231 and BT-474 / Negin Karimian." Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2019. http://d-nb.info/1202044360/34.

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Luzete, Beatriz Christina. "Efeitos do ácido docosahexaenoico (DHA) e do ácido araquidônico (AA) sobre a morte celular da linhagem celular de câncer de mama MDA-MB-231." reponame:Repositório Institucional da UnB, 2015. http://dx.doi.org/10.26512/2015.10.D.18908.

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Dissertação (mestrado)—Universidade de Brasília, Faculdade de Ciências da Saúde, Programa de Pós-Graduação em Nutrição Humana, 2015.
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O ácido docosahexaenóico (DHA) possui efeito antitumoral em células de câncer de mama pela diminuição da proliferação celular e pelo aumento da morte por apoptose. Já o ácido araquidônico (AA) está relacionado ao crescimento e à progressão tumoral. Nenhuma pesquisa até o momento indicou a indução de morte por piroptose pelo DHA. O presente estudo buscou avaliar o efeito do DHA e do AA na indução de morte por apoptose e piroptose em células de câncer de mama triplo-negativo MDA-MB-231. Metodologia: MDA-MB-231 foi tratada com diferentes concentrações de DHA ou AA. A quantificação da morte por apoptose foi feita por marcação com Anexina-V/PI. Foram analisadas a integridade da membrana, a expressão de caspase 1 ativa e clivada, a secreção de IL-1β e a translocação de NFkB e de HMGB1 para avaliar a morte por piroptose. Resultados: O DHA levou ao aumento da morte por apotose em 50, 100 e 200μM e o AA, apenas em 200μM. O DHA aumentou a perda da integridade da membrana, a ativação e a clivagem de caspase 1, a secreção de IL-1β e a translocação de HMGB1 na concentração de 100μM, indicando ativação da morte por piroptose. Conclusão: O DHA induz morte por apoptose e piroptose em células de câncer de mama triplo-negativo e leva a um maior aumento da apoptose quando comparado ao AA.
Docosahexaenoic acid (DHA) decreases breast cancer cell proliferation and increases cell death by apoptosis. Arachidonic acid (AA) is known to promote tumor growth and progression. No study to date has indicated the induction of pyroptosis by DHA. This study evaluated the effect of DHA and AA on apoptosis and pyroptosis in triple negative breast cancer cells MDA-MB-231. Method: MDA-MB-231 were supplemented with different concentrations of DHA and AA. The quantification of cell death by apoptosis was made by Annexin-V / PI. Membrane integrity, active and cleaved caspase 1, secreted IL-1β and translocated NFkB and HMGB1 were analysed to check pyroptosis. Results: DHA increased apoptosis at 50, 100 and 200μM. AA also increased apoptosis in a higher concentration (200μM). DHA increased loss of membrane integrity, caspase 1 activation and cleavage, IL-1β secretion and HMGB1 translocation at 100μM, indicating pyroptosis activation. Conclusion: DHA induce apoptosis and pyroptosis in triple negative breast cancer cells and promotes a higher increase in apoptosis than do AA.

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Brumana, Giselle Xavier Reis. "Efeitos do inibidor de proteases Black-Eyed Pea Trypsin Chymotrypsin Inhibitor (BTCI) na viabilidade e proliferação de células MDA-MB-231 de adenocarcinoma mamário." reponame:Repositório Institucional da UnB, 2015. http://dx.doi.org/10.26512/2015.03.D.19715.

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Dissertação (mestrado)—Universidade de Brasília, Faculdade de Medicina, Programa de Pós-Graduação em Patologia Molecular, 2015.
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O adenocarcinoma mamário, assim como outras manifestações do câncer, é o fenótipo patológico desencadeado por processos multifatoriais e desenvolvimento multiprocessual, decorrente de alterações do controle de proliferação e crescimento celular. Nesse estudo os efeitos do inibidor de proteases black-eyed pea trypsin chymotrypsin inhibitor (BTCI) foram avaliados na viabilidade e proliferação de células de adenocarcinoma mamário (MDA-MB-231), in vitro, visando caracterizar o BTCI como potencial agente anticarcionogênico nesse tipo de câncer, ensaios de viabilidade celular, avaliações de morte celular e ciclo celular por citometria de fluxo, bem como o estudo da geração de espécies moleculares reativas de oxigênio (EROS). A partir da determinação da Concentração Inibitória (IC50) de BTCI (267,4 µM em 24 horas) a interferência deste inibidor sobre o ciclo celular da linhagem em questão foi avaliada e um aumento do número de células na fase G2 foi observado, assim como a presença de DNA fragmentado. A via de morte das células de adenocarcinoma mamário tratadas com BTCI foi estudada e constatou-se que a média das células que sofreu morte por apoptose foi de 89,4%, valor significativo, sendo p<0,001. Ademais, o processo de oxidação celular via Espécies Reativas de Oxigênio (EROS) foi intensificado em 24h de incubação. Os resultados obtidos indicam que o BTCI causa efeitos citostático e citotóxico nas células analisadas, sendo a principal via de morte celular a apoptose, processo que pode estar associado à oxidação celular através de radicais livres de oxigênio.
The mammary adenocarcinoma as well as other manifestations of cancer, is the pathological phenotype triggered by multifactorial processes and multiprocessual development, due to proliferation and cell growth control changes. In this study the effects of the black-eyed pea trypsin chymotrypsin protease inhibitor (BTCI) were evaluated in breast adenocarcinoma cell (MDA-MB-231) proliferation and feasibility in vitro, in order to characterize the BTCI as a potential anticarcinogenic agent for this type of cancer cell. Thus viability assays, assessments of cell cycle and cell death by flow cytometry, as well as study of the generation of reactive oxygen molecular species (ROS) were performed. Upon determining the inhibitory concentration (IC50) of BTCI (267.4 uM in 24 hours) the interference of the inhibitor on cell cycle was evaluated and an increased number of cells in the G2 phase was observed, as well as presence of fragmented DNA. The death pathway of mammary adenocarcinoma cells treated with BTCI was studied and it was found that the average of the cells that entered death process by apoptosis was 89.4%, significant value p<0.001. Furthermore, cell oxidation process via Oxigen Reactive Species (ROS) was intensified after 24 hours of incubation. The results indicate that BTCI has cytostatic and cytotoxic effects on the analyzed cells. The main pathway of cell death was apoptosis, a process that may be associated with cellular oxidation by oxygen free radicals.

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Guimarães, Denise de Oliveira. "Avaliação “in vitro” do efeito antitumoral e antiangiogênico de uma metaloprotease isolada da peçonha de Bothrops pauloensis." Universidade Federal de Uberlândia, 2016. https://repositorio.ufu.br/handle/123456789/19203.

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O câncer de mama é uma neoplasia altamente maligna e continua a ser a segunda principal causa de mortalidade entre as mulheres. Os efeitos antitumorais de metaloproteinases e desintegrinas de veneno de serpentes têm sido investigados em vários tipos de células tumorais. Neste estudo, foram avaliados os efeitos antitumorais e anti-angiogênicos induzidos pela Bothropoidina, uma metaloproteinase desintegrina-like isolada da peçonha de Bothrops pauloensis em células de câncer de mama humano MDA-MB-231 e células endoteliais. Após 24 horas de tratamento com 100pg/mL de Bothropoidina foi constatado um efeito citotóxico moderado de 30% em MDA-MB-231 contra 10% de citotoxicidade em MCF10A (uma linha de células da mama não tumorigênica), uma diferença significativa que sugere uma possível preferência desta proteína por alvos em células tumorais. Observou-se apoptose e apoptose tardia após tratamento com Bothropoidina (10pg/mL e 40pg/mL) em células MDA-MB-231. Além disso, esta toxina não só inibiu a adesão de células MDA-MB-231 de uma forma dose dependente, como a migração celular em aproximadamente 45%. Bothropoidina reduziu a viabilidade e adesão de células endoteliais em Matrigel e inibiu a angiogênese in vitro estimulada por bFGF em Matrigel, mostrando um número de vasos formados significativamente menor em relação ao controle. Os resultados demonstraram que Bothropoidina tem um potente efeito antitumoral e antiangiogênico in vitro, representando uma ferramenta biotecnológica para elucidar o efeito antitumoral de metaloproteinases desintegrinas-like em células cancerígenas.
Breast cancer is a highly malignant carcinoma and remains the second leading cause of mortality among women. The antitumor effects of metalloproteinases and disintegrins from snake venom on various types of cancer cells have been investigated. In this study, we evaluated the antitumor and antiangiogenic effects on MDA-MB-231 human breast cancer cells and endothelial cells induced by Bothropoidin, a disintegrin-like metalloproteinase isolated from Bothrops pauloensis snake venom. At 24h after treatment at 100pg/mL, Bothropoidin exerted a moderate cytotoxic effect of 30% on MDA-MB-231 versus 10% cytotoxicity against MCF10A (a non-tumorigenic breast cell line), a significant difference that suggests a possible preference by this protein for targets in cancer cells. Early and late apoptosis of MDA-MB-231 was observed after Bothropoidin treatment (10gg/mL and 40gg/mL). Furthermore, this toxin inhibited not only the adhesion of MDA-MB-231 cells in a dose-dependent manner but also cell migration by approximately 45%. In addition, Bothropoidin decreased endothelial cells viability and adhesion in Matrigel and inhibited in vitro angiogenesis in Matrigel stimulated by bFGF, showing significantly fewer formed vessels. The results demonstrated that Bothropoidin has potent in vitro antitumor and antiangiogenic effect and represents a biotechnological tool for elucidating the antitumor effect of disintegrins-like metalloproteinases in cancer cells.
Dissertação (Mestrado)

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Hantak, Alison Marie. "Ginsenosides enhance the cytotoxicity of tumor necrosis factor-[alpha] in human MDA-MB 231 and MCF-7 breast cancer cells in a caspase-dependent manner /." Available to subscribers only, 2009. http://proquest.umi.com/pqdweb?did=1967998531&sid=1&Fmt=2&clientId=1509&RQT=309&VName=PQD.

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Fortier, Audrey. "Étude sur les effets anti-prolifératifs et cytocides des antagonistes des kinines sur la lignée cancéreuse MB-MDA-231 implication potentielle des récepteurs B2 nucléaires." Mémoire, Université de Sherbrooke, 2007. http://savoirs.usherbrooke.ca/handle/11143/3895.

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Les récepteurs couplés à des protéines G (RCPG) constituent une superfamille de protéines dont la fonction principale est de transmettre les informations de médiateurs extracellulaires à travers la membrane plasmique vers l'intérieur de la cellule. Toutefois, un nouveau concept supporte la présence des RCPGs au niveau de la membrane nucléaire de plusieurs types cellulaires incluant les cellules cancéreuses. Dans ce dernier cas, les fonctions véhiculées par les RCPG nucléaires (s'il y a lieu) demeurent encore obscures. Par ailleurs, nos travaux initiaux ont montré la présence des récepteurs B2 (rB2), un RCPG prototypique, chez des lignées cancéreuses d'origine variée (ex. MB-MDA-231, A549, U87, HL60, H69) par les techniques de RT-PCR et d'immunobuvardage Western. De plus, une expression constitutive des rB2 de la bradykinine (BK) au niveau (péri)nucléaire a été révélée par immunofluorescence indirecte chez la lignée MB-MDA-231. Nous avons émis l'hypothèse que les rB2 nucléaires participent en partie, aux mécanismes de signalisation liés à la prolifération et/ou survie des cellules MB-MDA-231. Pour tester cette hypothèse, des nouveaux composés agonistes et antagonistes peptidiques perméables aux cellules (TAT-BK, TAT-HOE 140) et spécifiques aux rB2 ont été conçus par un procédé de vectorisation utilisant un analogue du peptide Tat du virus VIH.Les effets de ces composés fusogènes et de leur homologue non vectorisé (BK, HOE 140) ainsi que de l'antagoniste rB2 non peptidique FR173657 (présumément perméable) sur la prolifération et la viabilité cellulaire ont été mesurés par des tests de clonogénicité et de croissance en agar mou et, MTT, respectivement. Les résultats obtenus ont montré que la stimulation avec le TAT-BK augmente la prolifération des cellules MB-MDA-231; cet effet a été inhibé par un traitement concomitant avec le TAT-HOE 140 ou encore le FR173657. De plus, on a observé une inhibition marquée concentration-dépendante de la prolifération et de la viabilité pour les antagonistes TAT-HOE 140 et FR173657 suggérant que le rB2 nucléaire possède une activité de base en lien avec ces processus physiologiques. Aucune activité n'a été observée pour le peptide contrôle Tat, la BK et le HOE 140, employé individuellement, dans tous les tests de mesure utilisés.Les résultats de cette étude décrivent, pour la première fois, un rôle potentiel des rB2 nucléaires dans la biologie du cancer notamment dans les voies de signalisation associées à la survie/prolifération des cellules MB-MDA-231.

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Santos, Emerson de Souza. "Análise por microarray de genes diferencialmente expressos em linhagem celular de câncer de mama (MDA-MB-231) tratada com o peptídeo bioativo da laminina C16." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/42/42134/tde-10022012-135951/.

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O câncer de mama representa importante problema de saúde pública. O microambiente tumoral tem participação no câncer. Peptídeos derivados da laminina estão envolvidos com progressão tumoral. O peptídeo C16 (KAFDITYVRLKF), da cadeia gama-1 da laminina, estimula adesão, migração e invasão celular, metástase e angiogênese. Para avaliar o efeito deste peptídeo na expressão gênica de células de câncer de mama (MDA-MB-231), células foram tratadas com C16 ou peptídeo controle (FKLRVYTIDFAK) por 24 horas. Após tratamento, a expressão gênica foi avaliada por microarray. C16 regulou a expressão de 80 genes em células MDA-MB-231, incluindo genes associados ao câncer. Os genes FGFR3, GPNMB e SPOCK1 tiveram suas expressões aumentadas após tratamento com C16, como confirmado por PCR quantitativo. Ensaios de invasão em câmaras de Boyden também indicam que C16 estimula invasão de células MDA-MB-231, porém C16 não mostrou efeito sobre proliferação e apoptose. Nossos dados sugerem que o peptídeo C16 regula expressão gênica e estimula invasão de células de câncer de mama MDA-MB-231.
Human breast cancer constitutes a worldwide health care problem. During cancer progression, tumor cells are engaged in an interplay with their microenvironment. Studies have shown that peptides derived from laminin are involved in tumor progression. Among them, C16 (KAFDITYVRLKF), derived from laminin gamma-1 chain, is a cell-adhesive peptide that increases cell migration, invasion, metastasis and angiogenesis. This prompted us to analyze whether C16 would regulate gene expression in human breast cancer cells (MDA-MB-231). Cells were treated with C16 or scrambled peptide control (FKLRVYTIDFAK) for 24 hours and gene expression was analyzed by microarray. Eighty genes were regulated by C16, including genes associated with cancer. Among them, FGFR3, GPNMB and SPOCK1 expression was increased by C16, as confirmed by qPCR. C16 also increased MDA-MB-231 cell invasion. However, no effect on cell proliferation and apoptosis was observed. Concluding, our data suggest that C16 regulates gene expression and enhances invasion of metastatic MDA-MB-231 breast cancer cells.

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Abdelkarim, Mohamed. "Effets anti-métastatiques de nouveaux m-bromobenzyl bisphosphonates non azotés et caractérisation de nouvelles lignées invasives issues d’un adénocarcinome métastatique de sein (MDA-MB-231)." Paris 13, 2009. http://www.theses.fr/2009PA132020.

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La progression métastatique est la cause majeure de mortalité liée au cancer. L’approfondissement des connaissances sur la formation des métastases permet d’améliorer les traitements existants et d’identifier de nouvelles cibles thérapeutiques. La première partie de ce travail nous a permis de démontrer l’efficacité d’une nouvelle génération de bisphosphonates (BPs) non azotés avec un groupement bromo-benzyl au niveau de leur chaine latérale et avec ou sans alkylation des groupements phosphonates (BP7033Br et BP7033Br ALK). Ces deux BPs sont capables, in vitro, d’inhiber la prolifération, la motilité et l’invasion des cellules de cancer du sein MDA-MB-231. De plus, ils sont capables d’inhiber, in vivo, la croissance et l’angiogenèse tumorale chez la souris athymique. Seul le BP7033Br ALK est capable d’inhiber la formation des métastases osseuses et extra-osseuses dans un modèle de progression métastatique utilisant un système d’imagerie par bioluminescence IVIS (xenogen). Ce résultat montre que l’estérification des groupements phosphonates améliore les propriétés des BPs notamment au niveau des tissues extra-osseux et permet d’envisager de nouvelles applications thérapeutiques. La deuxième partie a permis d’établir et de caractériser, in vitro et in vivo, deux nouvelles lignées cellulaires INV (invasive) et REF (référence) ayant des capacités invasives différentes. Les cellules INV sont 4 fois plus invasives que les cellules REF. Dans cette étude nous avons montré, in vitro, que les cellules INV prolifèrent moins rapidement, qu’elles sont plus résistantes à l’apoptose et qu’elles expriment plus du facteur angiogéniques et ses récepteurs (VEGF, VEGFR2 et NRP1). In vivo, les cellules INV sont capables de développer des tumeurs sous-cutanées, plus volumineuses et plus angiogéniques par rapport aux cellules REF. En injectant ces deux lignées en intracardiaque, nous avons montré que les cellules INV forment plus de sites métastatiques par rapport aux cellules REF et diminue la survie des souris. L’ensemble de ce travail montre d’une part l’intérêt de l’estérification des groupements phosphonates pour cibler des métastases autres qu’osseuses, et d’autre part le rôle important du phénotype invasif d’une lignée de cancer de sein métastatique, dans la progression tumorale
The metastatic progression is the main cause of death in cancer. Increasing our knowledge of the molecular and cellular mechanism of the formation of metastasis possibly allow to identify new treatments. In the first part of this work, we developed two new bisphosphonates (m-Bromobenzyl non-aminobisphosphonates; “BP7033Br” and symmetrically esterified with hydrophobic 4-methoxphenyl; “BP7033Br ALK”) in order to develp new strategy to overcome BPs hydrophilicity by masking the phosphonic acid through organic protecting groups and introducing hydrophobic functions in the side chain. We have demonstrated that BP7033Br and BP7033Br ALK inhibited, in vitro, the proliferation, motility and invasion of MDA-MB-231 breast cancer cells. Although both compounds inhibited tumor growth without side effects, only the BP7033Br ALK abrogated D3H2LN cell-induced metastases formation. In the second part of this work, we have isolated two invasive subpopulations from MDA-MB-231 cells using Matrigel coated Boyden chambers. We showed that very invasive cells designed INV cells, were 4-fold and 3-fold more invasive and motile than non invasive ones (REF cells), respectively. INV cells were less adhesive than REF cells to endothelial cells or to the major ECM component, fibronectin. Although INV subpopulation cells grew 2-fold slower than REF cells in vitro, tumors from INV cells xenografted in nude mice presented higher volume and more angiogenesis. This angiogenesis phenotypic difference was associated with a more important expression in VEGF, NRP-1 and VEGFR2 receptors. In addition, we showed that INV cells were more resistant to doxorubicin treatment as well as to growth factors starvation. INV cells when injected into blood circulation of nude mice induced more metastasis sites as compared to REF ones and dramatically diminished of about 80% the mice survival. Transcriptomic analysis of INV and REF cells showed modulation of genes expression involved in adhesion and resistance to apoptosis. In conclusion, invasive phenotype was sufficient to induce metastasis formation correlated with poor endothelial and ECM adhesion, survival and angiogenesis abilities

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Sprouse, Alyssa A. "Resveratrol augments paclitaxel treatment in MDA-MB-231 and paclitaxel-resistant MDA-MB-231 breast cancer cells." Thesis, 2014. http://hdl.handle.net/1805/6165.

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Indiana University-Purdue University Indianapolis (IUPUI)
Resveratrol has been shown to inhibit cell growth and induce apoptosis, as well as augment chemotherapeutics and irradiation in multiple cancer types. However, it is unknown if resveratrol is beneficial for treating drug-resistant cancer cells. To study the effects of resveratrol in triple negative breast cancer cells that are resistant to the common cancer drug, paclitaxel, a novel paclitaxel-resistant cell line was generated from the MDA-MB-231 breast cancer cell line. The resulting cell line, MDA-MB-231/PacR, exhibited a 12-fold increased resistance to paclitaxel but remained sensitive to resveratrol treatment. Resveratrol treatment reduced cell proliferation and colony formation and increased senescence and apoptosis in both the parental MDA-MB-231 and MDA-MB-231/PacR cell lines. Importantly, resveratrol treatment augments the effects of paclitaxel in both cell lines. The expression of the drug efflux transporter gene, MDR1, and the main metabolizing enzyme of paclitaxel gene, CYP2C8, was increased in the resistant cells. Moreover, pharmacological inhibition of the protein products of these genes, P-glycoprotein and CYP2C8, decreased paclitaxel resistance in the resistant but not in the parental cells, which suggests that the increase of these proteins are important contributors to the resistance of these cells. In conclusion, these studies imply that resveratrol, both alone and in combination with paclitaxel, may be useful in the treatment of paclitaxel-sensitive and paclitaxel-resistant triple negative breast cancers.

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Mottlová, Petra. "Vliv valencenu na adhezi prsní nádorové linie MDA-MB-231." Master's thesis, 2015. http://www.nusl.cz/ntk/nusl-331691.

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Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Bc. Petra Mottlová Supervisor: Ing. Petra Matoušková, Ph.D. Title of diploma thesis: Effect of valencene on adhesion of breast cancer cell line MDA-MB-231 Valencene belongs to sesquiterpenes and is constituent of essential oils of many plants. It is the main citrus flavoring component. Valencene is mainly used in the food and cosmetic industries, but recent studies have confirmed its biological activity. Its antitumor, antiinflammatory, antioxidant and antiallergic effects have been already proven. The objective of this study was to determine the cytotoxic effect and influence on the adhesion of sesquiterpene valencene on breast cancer cell line MDA-MB-231. Another objective was to study the mechanism of its effect from the perspective of the selected adhesion molecules, which have an important role in tumorigenesis and metastasis. Valencene's cytotoxic effect was tested with use of neutral red (NRU test). Valencene influence on cell adhesion was continuously monitored by means of the X-Celligence device and expression of selected adhesion molecules was studied by Western blot and qPCR methods. The results showed a slight cytotoxic effect of valencene. Cell viability was over 70% at a...

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Marešová, Markéta. "Vliv alfa-humulenu na adhezi prsní nádorové linie MDA-MB-231." Master's thesis, 2015. http://www.nusl.cz/ntk/nusl-331745.

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Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Bc. Markéta Marešová Supervisor: Ing. Petra Matoušková, Ph.D. Title of diploma thesis: Effect of alpha-humulene on adhesion of breast cancer cell line MDA-MB-231 α-humulene is a sesquiterpene contained in the essential oil of Chinese Bayberry (Myrica rubra), which has various biological effects. The aim of this thesis was to study the cell adhesion of tumor cell line MDA-MB-231, and the effects of α-humulene on expression of cell adhesion molecules. Furthermore, the cytotoxic effect of α-humulene on this cell line was verified. Effect of α-humulene on cell proliferation was evaluated by neutral red uptake test (NRU test) and by xCelligence system. Cell adhesion was also continuously monitored by xCelligence. Expression ganges of cell adhesion molecules upon α-humulene treatment were determined by Western blotting and by quantitative polymerase chain reaction on the protein and mRNA levels, respectively. The proliferation of the cells was significantly affected by α-humulene after 24 hour treatment (IC50 13.6 µg/ml). α-humulene alone caused slightly increased cell adhesion. Adhesion molecules EpCAM and β-cathenin were almost unaffected. Level of ICAM1 mRNA was increased after 12 hours and...

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Tůmová, Veronika. "Vliv vybraných seskviterpenů na účinek cytostatik u buněčné linie MDA-MB-231." Master's thesis, 2016. http://www.nusl.cz/ntk/nusl-346928.

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Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Title, Name, Surname of candidate: Veronika Tůmová Title, Name, Surname of tutor: PharmDr. Hana Bártíková, Ph.D Title of a diploma work: The influence of selected sesquiterpenes on the effect of cytostatics for the cell line MDA-MB-231 Breast cancer is one of the most common forms of cancer. It makes up approximately one quarter of cancer cases amongst women. The rise in the incidence of this disease in western countries has, over recent years, been linked to a lifestyle that characteristically involves a sedentary way of life and a diet rich in animal fats. There are currently many therapeutic regimes available for the treatment of breast cancer which are increasingly adapted to the individual needs of the patient and their specific tumor subtype. In spite of the wide range of treatments with a variety of mechanisms of effects on cancer tissues, current treatments are limited by inadequate effectiveness, serious undesirable side effects or the occurrence of resistance. Scientists have therefore been attempting to uncover ways to prevent these undesired effects. Sesquiterpenes α humulene and trans-nerolidol are naturally-occuring substances that, through their biochemical effects, act cytotoxically...

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Bieber, Daniela. "Der A2B-Adenosinrezeptor und MAP-Kinase Aktivität in MDA-MB-231 Brustkrebszellen." Doctoral thesis, 2010. https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-65707.

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Sowohl MAPK als auch Adenosin werden mit Tumorproliferation und Angiogenese in Verbindung gebracht. MDA-MB-231 Östrogenrezeptor-negative Brustkrebszellen zeigen eine sehr starke Expression des A2BAR, der außerdem der einzige von dieser Zelllinie exprimierte Adenosinrezeptor ist. Es konnte gezeigt werden, dass MDA-MB-231-Brustkrebszellen eine hohe basale MAPK-Aktivität aufweisen, welche durch Stimulation mit FCS nicht weiter gesteigert werden kann. Diese hohe basale MAPK-Aktivität wird durch die src-Kinase und Her2 verursacht, da eine Inhibition dieser beiden Tyrosinkinasen eine Hemmung der basalen ERK-Phosphorylierung induziert. Interessanterweise führt die Stimulation des A2BAR der MDA-MB-231-Brustkrebszellen mit dem unselektiven Agonisten NECA zu einer zeitanhängigen Inhibition der ERK-1/2-Phosphorylierung. Eine Behandlung der Brustkrebszelllinie mit 10 µM CGS 21680 zeigten keinen Einfluss auf die ERK-Aktivität, weshalb davon ausgegangen werden kann, dass die zeitabhängige Inhibition der ERK-1/2-Phosphorylierung durch den A2BAR vermittelt wird. Eine Beteiligung von cAMP an der MAPK-Signaltransduktion des A2BAR scheint insofern wahrscheinlich, als sowohl eine Behandlung der Zellen mit Forskolin als auch der Kombination aus cAMP-AM und dem PDE4-Inhibitor Rolipram eine zeitabhängige Hemmung der ERK-1/2-Phosphorylierung induzieren. Jedoch scheint weder die PKA noch die PI3K an dieser Signaltransduktion des A2BAR beteiligt zu sein, da die A2BAR-vermittelte Inhibition der MAPK auch in Anwesenheit von PKA- und PI3K-Inhibitoren bestehen bleibt. Auch scheinen cAMP-GEFs wie beispielsweise Epac in diesem Zusammenhang keine Rolle zu spielen. In Gegenwart des PLC-Inhibitors U-73122 und des Ca2+-Chelators BAPTA verschwand die NECA-induzierte Hemmung der ERK-1/2-Phosphorylierung, was für eine Beteiligung der PLC und des Ca2+ an der A2BAR-vermittelten Hemmung der MAPK-Aktivität spricht. Letzten Endes konnte jedoch kein Mechanismus eruiert werden, welcher diese A2BAR-vermittelte, Ca2+-abhängige MAPK-Hemmung mediiert, da weder eine Inhibition der PKC, der CamKII oder des Calcineurins Einfluss auf die NECA-induzierte MAPK-Hemmung hatten. Was Wachstum und Proliferation der Östrogenrezeptor-negativen Brustkrebszelllinie MDA-MB-231 anbelangt, so konnte gezeigt werden, dass der unselektive Agonist NECA zu einer signifikanten Wachstumshemmung dieser Brustkrebszelllinie führt. Allerdings kommt es aufgrund einer Desensitisierung der A2BAR in MDA-MB-231-Brustkrebszellen lediglich zu einem transienten proliferationshemmenden Effekt nach Stimulation mit NECA
MAP kinases as well as adenosine are involved in angiogenesis and proliferation of malignant tumors. The estrogen receptor-negative breast cancer cell line MDA-MB-231 expresses A2B adenosine receptors (A2BAR) as the sole adenosine receptor subtype at remarkably high levels. These MDA-MB-231 cells show a very high basal MAPK activity which seems to be maximal as it can not be stimulated further with FCS or EGF. This high basal MAPK activity is caused by src-kinase and her2, as inhibition of these two tyrosinkinases induces an inhibition of basal ERK1/2 phosphorylation. Interestingly, stimulation of A2BAR in MDA-MB-231 breast cancer cells with the unselective agonist NECA leads to a time-dependent inhibition of ERK1/2 phosphorylation whereas treatment of the cells with 10 µM CGS 21680 had no influence on ERK-activity. Thus it can be assumed that the time-dependent inhibition of ERK1/2 phosphorylation is mediated via the A2BAR subtype. A role of cAMP for the MAPK signal transduction of the A2BAR seems to be likely because stimulation of the cells with Forskolin as well as treatment with a combination of cAMP-AM and the PDE4-inhibitor Rolipram results in a time-dependent inhibition of ERK1/2 phosphorlyation. However, neither PKA nor PI3K seem to be involved in the signal transduction of the A2B adenosine receptor, as the A2BAR-mediated inhibition of MAPK persists in the presence of PKA- and PI3K-inhibitors. CAMP-GEFs like EPAC do not seem to play a role in this signal transduction mechanism either. The presence of the PLC-inhibitor U-73122 and the Ca2+-chelator BAPTA abolishes the NECA effect, suggesting a role for PLC and Ca2+ for the A2BAR-mediated inhibition of ERK1/2 phosphorylation. Finally, a mechanism leading to this A2BAR-mediated and Ca2+-dependent MAPK inhibition could not be found out because neither an inhibition of PKC, nor inhibition of CamKII or Calcineurin had an influence on the NECA effect. Concerning growth and proliferation of MDA-MB-231 breast cancer cells it could be shown that the unselective agonist NECA leads to a slight but significant growth inhibition in these cells. However, this proliferation-inhibiting effect of NECA is only transient because of a desensitization of A2B adenosine receptors in these breast cancer cells

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Yang, Ming-Xian, and 楊明憲. "Identification of cellular targets for inhibiting MDA-MB-231 migration and invasion." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/y4mdn9.

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碩士
國立臺灣大學
生化科學研究所
107
Metastasis is a formidable process during tumor progression, often leading existing therapies to failure. As a result, there has been an unmet need for targeted therapies to effectively inhibit cancer metastasis. An iodoacetamide-based covalent inhibitor, I-Trp, was previously demonstrated to be capable of alkylating Cys354 of β-tubulin to disrupt the protein-protein interaction between β-tubulin and CCT-β, thus inducing apoptosis of CCT-β overexpressed cancer cells, including MDA-MB-231, a TNBC, which was used to test I-Trp on inhibiting its metastasis. In this study, a sub-IC50 concentration of I-Trp was found to decrease the migration and invasion of MDA-MB-231 by 70-80%. To identify the potential target for I-Trp inhibiting cell migration and invasion, total cellular proteins were treated with an I-Trp-derived fluorescent probe. The proteins labeled by I-Trp were further expressed in MDA-MB-231 to study their alkylating sites of I-Trp. One of the proteins, Rab5c, which has been reported to involve in metastasis, was mutated at the alkylating sites and transfected into MDA-MB-231 to test its role in I-Trp inhibiting cell migration and invasion. Cys20 and Cys64 of Rab5c were found to be alkylated by I-Trp and the alkylation resulted in suppression of MDA-MB-231 migration and invasion. In conclusion, this study combined with our previous findings show that I-Trp targets β-tubulin and Rab5c, thereby inducing cancer cell apoptosis and inhibiting cancer cell migration and invasion.

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45

Rossin, Michele. "Chronic hypoxia induces dormancy in breast cancer cell line MDA-MB-231." Doctoral thesis, 2018. http://hdl.handle.net/11562/979184.

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The tumor microenvironment (TME) is recognized as a key factor in multiple stages of disease progression, local resistance, immune-escaping and metastasis. TME is the product of developing crosstalk between different cells types and components, which provide an essential communication network through the secretion of growth factors and chemokines, and induce oncogenic signals enhancing cancer-cell proliferation and invasion. The rapid proliferation of tumor cells and the aberrant structure of the blood vessels within tumors result in a marked heterogeneity in the perfusion of the tumor tissue with regions of low oxygen or hypoxia. Although most of the tumor cells die in these hypoxic conditions, a part of them can adapt and survive for many days or months in a dormant state. Dormant tumor cells are characterized by cell cycle arrest in G0/G1 phase as well as low metabolism and, are refractive to common chemotherapy giving rise to metastasis. Despite these features, the cells retain their ability to proliferate when conditions improve. Exposing human breast cancer cell line exposure MDA-MB-231 to at least three cycles of 1% O2 hypoxia and reoxygenation, we select a subpopulation of hypoxia resistant cells. These cells, designed as chMDA-MB-231, stably survive under 1% O2 hypoxia condition by entering in dormant state. The reprogramming of cells into tumor dormancy results from the low p-ERK/p-p38 ratio that is described as the molecular switch of tumor dormancy in restrictive environment. This dormant state is reversible since once replaced in normoxia the cells recover the proliferation rate in 2 weeks. Moreover, the data in this thesis demonstrate that cycling hypoxic/reoxygenation stress selects dormant MDA-MB-231 cells that present the cancer stem-like phenotype characterized by CD24-/CD44+/ESA+ expression and spheroid forming capacity. Different reports recognize autophagy as a mechanism activated by microenvironment stresses that may contribute to survival of cells in tumor dormancy. Interestingly, we found that chMDA-MB-231 cells have a high level of autophagy, as measured by the detection of autophagolysome and LC3-II expression, suggesting that autophagy may be the survival mechanism of dormant chMDA-MB-231 cells. We believe that the proposed experimental approach to select dormant breast cancer cells could provide a rationale for the development of novel agents to target dormant tumor cells population.

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46

Tsai, Yi-Hsiu, and 蔡易修. "Different Mechanisms of Berberine-induced Anti-proliferation Effects in Triple Negative Breast Cancer MDA-MB-231 and MDA-MB-468 Cell Lines." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/74561788716606686662.

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碩士
國立陽明大學
傳統醫藥研究所
105
Breast cancer is the leading cause of cancer death among females worldwide and ranks 4th in Taiwan. Among the different subtypes, triple negative breast cancer (TNBC), lack of estrogen-receptor (ER), progesterone-receptor (PR) and human epidermal growth factor receptor 2 (HER2) expressions, is characterized by its higher aggressiveness, higher recurrence rate, and poorer prognosis. Although there are emerging targeted therapies developed, the treatment of TNBC remains difficult clinically. Berberine, one of the main active components of traditional Chinese medicine (TCM), Huanglian (Coptidis rhizome), it is a kind of isoquinoline alkaloids. Berberine was shown to be effective in inhibiting cell proliferation and promoting apoptosis in various cancer cells. However, the effects of berberine on TNBC cell lines remain unclear. The aim of this study was to investigate the cell inhibition effects of berberine in triple negative breast cancer (TNBC) cells. By using human TNBC cell lines MDA-MB-231 and MDA-MB-468 as in vitro model, anti-proliferative effects of berberine on TNBC cells were elucidated by MTT assay, trypan blue exclusion assay, and clonogenic assay. Cell necrosis, apoptosis, and autophagy were analyzed by cell morphology, flow cytometry, immunofluorescence staining and Western blot for LC3Ⅰ/Ⅱ, respectively. Cell growth-related signaling pathway AKT/ERK/p38 and cell cycle kinase complexes proteins expression were analyzed by Western blot. In vivo MDA-MB-231 bearing xenografted nude mice was used to study the combination effects of berberine and doxorubicin (DOX), compared to DOX alone group. Based on MTT assay and clonogenic assay, berberine concentration-dependently suppressed cell proliferation in MDA-MB-468 (0, 3, 6, 12 μM) and MDA-MB-231(0, 6.25, 12.5, 25 μM), but this inhibitory effect was not through cell necrosis, apoptosis, and autophagy. Cell cycle analysis showed that an increased S/G2/M fraction and a decreased G0G1 phase in berberine-treated MDA-MB-231 cells, while a decreased S/G2/M phase fraction was noticed in berberine-treated MDA-MB-468 line. By Western blot, berberine not only decreased the activation of AKT/ERK but also decreased the expression of Cyclin A and CDK1 in MDA-MB-231, while berberine increased the activation of p38 and decreased the expression of Cyclin D and CDK4 in MDA-MB-468. Moreover, a combination of berberine + DOX had a more tumor-suppressive effect than DOX alone group. Our results demonstrate that the anti-proliferation effects of berberine were through the different mechanism in TNBC MDA-MB-231 and MDA-MB-468 cell lines, which provides the potential of berberine in personalized TNBC therapy.

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47

Tsai, Ching-Yi, and 蔡瀞儀. "Protoapigenone induces apoptosis in the human breast cancer cell line MDA-MB-231." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/44589837510332120901.

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碩士
高雄醫學大學
天然藥物研究所碩士班
94
Protoapigenone, a flavonoid from Thelypteris torresiana, has been shown to cause cytotoxicity in several cancer cell lines. In the present study, protoapigenone inhibited the growth of MDA-MB-231, a human breast cancer cell line, with an IC50 value of 1.09 ?嵱. Protoapigenone-induced growth inhibition was associated with a strong G2-M arrests depending upon doses and treatment times. Apoptosis was evident in cells by increased sub-G1 cell population , and activation of caspase-9, caspase -3 and the cleavage of poly(ADP-ribose) polymerase; however, pretreatment of cells with a pan-caspase inhibitor z-VAD-fmk only partially decreased protoapigenone-induced apoptosis, suggesting the involvement of both caspase-dependent and -independent pathways. Interestingly, protoapigenone did not significantly affect the levels of pro-apoptotic protein, Bax, and anti-apoptotic proteins, Bcl-2 and Bcl-xL. Therefore, protoapigenone seems to induce apoptosis through a novel mechanism which is independent of Bcl-2 family proteins. MDA-MB-231 cells treated with protoapigenone induced a small increase in intracellular ROS levels; however, although both NAC and catalase prevented protospigenone-increased ROS, only NAC could prevent protoapigenone-induced apoptosis. Protoapigenone induced phosphorylation of Erk, JNK, and p38 in a time-dependent manner; moreover, proapigenone induced-apoptosis was partially prevented by inhibitors of these kinases. These results suggest that protpapigenone-induced apoptosis is, at least, partially dependent on MAPK. Further studies on the precise target of action of protoapigenone are needed.

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48

Chan, Mei-Ling, and 詹美玲. "Pristimerin induces apoptosis in the human breast cancer cell line MDA-MB-231." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/71744968772645938417.

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碩士
高雄醫學大學
天然藥物研究所碩士班
92
Abstract Pristimerin, a triterpenoid from plants, has been shown to cause cytotoxicity in several cancer cell lines. However, the mechanism for the cytotoxic effect of pristimerin was never explored. In the present study, pristimerin inhibited the growth of MDA-MB-231, a human breast cancer cell line, with an IC50 value of 0.61 mM. Pristimerin treatment increased the subG1 cell population of MDA-MB-231 cells, and caused the activation of caspase-3 and the cleavage of poly(ADP) ribose polymerase (PARP) in a concentration- and time-dependent manner. Furthermore, cells pretreated with a pan-caspase inhibitor Z-VAD-FMK markedly prevented pristimerin-induce apoptosis. These results suggest that pristimerin could induce caspase-dependent apoptosis in MDA-MB-231 cells. Interestingly, pristimerin did not significantly affect the levels of pro-apoptotic proteins, Bax and Bad, and anti-apoptotic proteins, Bcl-2 and Bcl-xL. Therefore, pristimerin seems to induce apoptosis in MDA-MB-231 cells through a novel mechanism which is independent of Bcl-2 family proteins. Cyclosporin A, a mitochondrial mitochondrial permeability transition pore (PTP) inhibitor, inhibited the pristimerin-induced cytochrome c release in a cell-free system and PARP cleavage in the intact cells. These suggested that pristimerin caused the opening of mitochondrial permeability transition pores, which resulted in cytochrome c release and following caspase-dependent apoptosis.

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49

Chen, Yung-Hsien, and 陳勇先. "Withanolides induce apoptosis in the human breast cancer cell line MDA-MB-231." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/69739642925459475180.

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碩士
高雄醫學大學
天然藥物研究所碩士班
95
4??-Hydroxywithanolide E (4HE), withaferin A (WA), and peruvianolide H (PAH) are withanolides from Solanaceae plants. In the present study, both 4HE and WA potently inhibited the growth of MDA-MB-231, a human breast cancer cell line, with IC50 values of 0.70 and 0.75 ?嵱, respectively. In contrast, PAH showed only weak antitumor activity. 4HE- and WA-induced growth inhibition was associated with G2/M cell cycle arrest. MDA-MB-231 cells treated with 4HE or WA showed induction of apoptosis, as indicated by morphological changes, increased subG1 cell population, caspase-3, -8, -9 activation, and the cleavage of poly(ADP-ribose)polymerase. Pretreatment of a pan-caspase inhibitor z-VAD-fmk significantly prevented either 4HE or WA-induced apoptosis. The levels of anti-apoptotic proteins, Bcl-2 and Bcl-XL, were decreased after 4HE or WA treatment. 4HE and WA also caused an increase in ROS generation and induced the expression of heat shock protein (Hsp)70. In addition, several Hsp90 client proteins (Raf, Cdk4, Cyclin D, and AKT) were degraded in 4HE- or WA-treated cells. All of these effects caused by 4HE and WA were prevented by N-acetylcysteine, an antioxidant and thiol-reducing agent . Taken together, our results suggest that the withanolides 4HE and WA induced cell cycle arrest and caspase-dependent apoptosis in human breast cancer MDA-MB-231 cells. Protein thiol oxidation and Hsp90 inhibition might be involved in the mechanism of 4HE- and WA-induced antitumor effect.

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50

Lokvencová, Kateřina. "Vliv vybraných isoflavonoidů na účinnost protinádorové léčby u buněčné linie MDA-MB-231." Master's thesis, 2015. http://www.nusl.cz/ntk/nusl-335913.

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Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Title, Name, Surname of candidate: Kateřina Lokvencová Title, Name, Surname of tutor: PharmDr. Hana Bártíková, Ph.D. Title of a diploma work: The impact of selected isoflavonoids on the effectiveness of anticancer therapy in MDA-MB-231 cell line. Breast cancer is the most common cancer disease in women. There is an extensive amount of therapeutic regimens for the treatment of this disease, but it is often limited by lack of efficiency or serious side effects. Isoflavonoids genistein (GEN), daidzein (DAID) and formononetin (FORM) belong among the natural substances with bioprotective effects on the human body. Some epidemiological studies have confirmed the protective effect of isoflavonoids against certain types of cancer, including breast cancer. The aim of this work was to study the effect of isoflavonoids on cancer cells and assess their ability to support the effect of cytostatics, namely anthracycline antineoplastic agents doxorubicin (Dox). For the experiments was chosen the breast cancer cell line MDA-MB-231. To study the effect of isoflavonoids on tumor cells we chose concentrations of 1 and 10 µM which is according to the bioavailability of isoflavonoids. We have shown that isoflavonoids...

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