Dissertations / Theses: 'ProteÃna p53'

1

AndrÃ, Angela Rosa. "AssociaÃÃo da presenÃa de Helicobacter pylori e dos genÃtipos caga e vaca com as alteraÃÃes moleculares dos supressores tumorais P53 e P27 nos adenocarcinomas gÃstricos." Universidade Federal do CearÃ, 2008. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=1819.

Full text

Abstract:

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior
O carcinoma gÃstrico Ã a segunda causa de morte por cÃncer no mundo. No CearÃ Ã o segundo mais freqÃente entre os homens e o terceiro entre as mulheres. Dos cÃnceres gÃstricos os adenocarcinomas representam em torno de 95%. A doenÃa tem sido associada a fatores genÃticos e ambientais sendo demonstrada Ãntima relaÃÃo com a infecÃÃo por Helicobacter pylori, principalmente associada Ã presenÃa do gene cagA e genÃtipos vacAs1m1. Entretanto, apesar dos mecanismos pelos quais a bactÃria promove a carcinogÃnese gÃstrica ainda nÃo estarem esclarecidos, uma das hipÃteses seria atravÃs da inativaÃÃo de supressores tumorais. O objetivo do presente trabalho foi verificar, em adenocarcinomas gÃstricos, se a presenÃa de H. pylori, e de seus genes cagA e vacA, estÃ relacionada com a mutaÃÃo e/ou alteraÃÃo na expressÃo protÃica dos supressores tumorais p53 e p27. Neste estudo, 74 amostras de pacientes foram analisadas quanto Ã presenÃa de H. pylori, cagA+ e os genÃtipos de vacA, pela reaÃÃo em cadeia da polimerase (PCR). A anÃlise mutacional do gene p53 foi realizada por PCR-SSCP e a detecÃÃo da mutaÃÃo/superexpressÃo do p53 e expressÃo da proteÃna p27 pelo mÃtodo imunohistoquÃmico. A bactÃria foi detectada em 95% das amostras, das quais 63% eram cagA(+). Dentre os alelos de vacA, observou-se predomÃnio de s1 (74%) e m1 (82%), associados em 69% dos casos. Na anÃlise mutacional do p53 verificou-se que 72% dos casos exibiram alteraÃÃo no padrÃo de mobilidade eletroforÃtica, sendo esta associada significativamente Ã presenÃa do gene cagA. Por outro lado, apenas 29% dos casos apresentaram detecÃÃo pelo mÃtodo imunohistoquÃmico, nÃo sendo encontrada associaÃÃo com a H. pylori. A proteÃna p27 demonstrou acentuada reduÃÃo em sua expressÃo (detectada em apenas 19% dos casos), nÃo demonstrando atividade compensatÃria em relaÃÃo Ã proteÃna p53 mutada e sem associaÃÃo estatÃstica dos casos negativos com a presenÃa da H. pylori. Finalmente, os resultados sugerem que estes supressores simultaneamente inativados podem ser o ponto chave da desregulaÃÃo do ciclo celular que, associados a outros fatores, favoreÃam o desenvolvimento e progressÃo dos adenocarcinomas gÃstricos. HÃ indÃcios de que a presenÃa bacteriana, e dos seus genes cagA(+) e vacA/s1m1, possam influenciar, de forma nÃo esclarecida, as alteraÃÃes moleculares ocorridas nos supressores tumorais p53 e p27.
Gastric carcinoma is the second cause of death by cancer in the world. On State of Ceara-Brazil is the second most frequent type of cancer in men and third in women. Adenocarcinomas account for approximately 95% of all malignant gastric neoplasms. It has been associated to genetic and environmental factors and a intimate relationship between the infection by the bacteria Helicobacter pylori and the gastric carcinoma have been related. The presence of the cagA gene and specific genotypes (s1m1) of the gene vacA have been detected in more pathogenic strains. Although the precise molecular mechanisms by which H. pylori could promote the process of gastric carcinogenesis are under investigation, one hypothesized mechanism involves the tumor supressor genes inactivation. The aim of the present study was to verify if the presence of Helicobacter pylori, cagA and vacA genes is related to mutations in the tumor supressor gene p53 and altered expression of p53 and p27 proteins in gastric adenocarcinomas. Seventy-four (74) samples were analyzed to detect the presence of H. pylori, cagA and genotypes of vacA by Polymerization Chain Reaction (PCR). The mutational analysis of p53 gene was performed by PCR-SSCP (Polymerization Chain Reaction for analysis of the Single-strand Conformation Polymorphism). Analysis of mutation or overexpression of p53 protein and p27 expression was detected by the immunohistochemical method. The bacteria was detected in 95% of the samples, 63% was cagA(+). Among the vacA allele it was observed prevalence of s1 (74%) and m1 (82%), associated in 69% of the cases. Mutation analysis of p53 demonstrated 72% of the cases with altered electrophoretic mobility; The alterations were significatively more frequent in the presence of the cagA gene. Immunohistochemical analysis detected only 29% of cases with the expression of p53 protein. The protein p27 showed accentuated reduction in its expression (detected in only 19% of the cases), it has not demonstrated compensatory activity in relation to the p53 altered protein, neither association to H. pylori presence. Finally, these data suggest that simultaneous inactivation of these tumor suppressors genes may be the key point of deregulation of the cellular cycle that, associated to the other factors, favor the development and progression of the gastric cancer. There is some evidence that the bacterial presence, cagA and vacA/s1m1 genes, may influence, in a not understood way, the alterations observed in the tumor suppressors p53 and p27.

APA, Harvard, Vancouver, ISO, and other styles

2

Marini, Wanda. "Comparing mutant p53 and a wild-type p53 isoform, p47 : rationale for the selection of mutant p53 in tumours." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=116033.

Full text

Abstract:

One of the major unresolved questions in cancer biology is why the majority of tumour cells express mutant p53 proteins. p53 is considered the prototype tumour suppressor protein, whose inactivation is the most frequent single genetic event in human cancer (Bourdon et al., 2005). Genetically-engineered p53-null knockout mice acquire multiple tumours very early on in life and human Li-Fraumeni families who carry germline mutations in p53 are highly cancer-prone (reviewed in Vousden and Lane, 2007). p53 mutant proteins have been found to acquire novel functions that promote cancer cell proliferation and survival, yet exactly why mutant p53s acquire oncogenic activity is still poorly understood. Mutant p53 has also been found to complex with wildtype p53, thus acting in a dominant negative way. However, this inhibition is incomplete since many cancers with mutant p53 alleles also have a loss of the second wild-type p53 allele and thus only express the mutant p53 (Baker et al., 1989). An N-terminal truncated p53 isoform, p47, arising from alternative splicing of the p53 gene (Ghosh et al., 2004) or by alternative initiation sites for translation (Yin et al. , 2002), has been described. Alternative splicing was found to be universal in all human multi-exon genes (Wang et al., 2008) and therefore determining the role of the p47 isoform with respect to the p53 gene is essential. Evidence in this study suggests that mutant p53 (p53RI75H) has a similar structure and function as p47, including the ability to complex with and impair both p53 and p73. Therefore, in addition to expressing a tumour suppressor protein, the p53 gene can also express an onco-protein (p47). This study therefore argues that tumours select for mutant p53 because it has gained the ability to function like p47, a wild-type p53 isoform.

APA, Harvard, Vancouver, ISO, and other styles

3

Xie, Tian. "Scintillation proximity assay (SPA) measuring p53 DNA binding and total p53 level in human thyroid cancer cell line ARO." Diss., Online access via UMI:, 2007.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

4

Protopopova, Marina. "Modulation of activity of the tumour suppressor p53 by small molecules and damaged DNA /." Stockholm, 2004. http://diss.kib.ki.se/2004/91-7349-926-9/.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Osadchuk, Olha. "Optimalizace izolace mutantního proteinu p53 a jeho DNA vazebné vlastnosti." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2020. http://www.nusl.cz/ntk/nusl-413550.

Full text

Abstract:

Protein p53 je jednou z nejdůležitějších molekul v lidském těle. P53 reguluje celou řadu procesů v buňce, jako je například oprava DNA, buněčný cyklus nebo indukce apoptózy. Protein p53 je známý i jako „strážce genomu“. DNA vazebné schopnosti proteinu p53 jsou důležité pro normální vývoj a růst buňky. Mutace genu pro p53 mohou vést ke ztrátě jeho DNA vazebných vlastností a funkce nádorového supresoru, což muže způsobit rozvoj rakoviny. Teoretická část této diplomové práce je zaměřena na popis vlastností, funkce a mechanismus aktivace proteinu p53 a popis lokálních sekundárních struktur DNA. Hlavním cílem experimentální části byla produkce čtyř mutantních forem proteinů p53 a wild-type p53 proteinu a studium jejich vazebných vlastnosti s různými lokálními sekundárními strukturami DNA. Pomoci Gateway klonovacího systému byly připraveny čtyři expresní vektory, které byly použity pro produkci proteinů v bakteriálním expresním systému. Celkem byly úspěšně připraveny čtyři mutantní formy a wild-type p53 protein. Jejich vazebné vlastnosti byly studovány gelovou retardační analýzu. Výsledky naznačují různé DNA-vazebné vlastnosti wild-type p53 a studovaných mutantních forem tohoto proteinu. Všechny mutantní proteiny ztratily schopnost sekvenčně specificky vázat DNA, zatímco nespecifická interakce s DNA byla pozorována u tří ze čtyř mutantních forem. Jeden ze studovaných mutantních proteinů se vázal jenom na superhelikální formu DNA.

APA, Harvard, Vancouver, ISO, and other styles

6

Cossi, Lucas Bahdour. "Detecção das proteínas p53, p63 e puma no carcinoma de células escamosas corneal de cães / Lucas Bahdour Cossi. -." Araçatuba, 2013. http://hdl.handle.net/11449/92182.

Full text

Abstract:

Orientador: Alexandre Lima de Andrade
Banca: Silmara Sanae Sakamoto de Lima
Banca: Flávia Rezende Eugênio
Resumo: As neoplasias oculares representam uma crescente preocupação na oftalmologia veterinária. O carcinoma de células escamosas (CCE) corneal é raro em cães, pouco estudado e as investigações sobre os mecanismos da carcinogênese são escassos. O presente trabalho teve por objetivo avaliar a imunoexpressão das proteínas p53, p63 e PUMA e suas possíveis contribuições quanto ao prognóstico e terapêutica no CCE corneal espontâneo de cães. Foram identificados seis casos, cinco diagnosticados como CCE e um como ceratite actínica. Na imunoistoquímica avaliou-se o número de células marcadas por campo no microscópio adotando-se dois critérios de classificação, quanto à intensidade e quanto à frequência de marcação. Também foi avaliada a graduação histológica dos tumores quanto ao grau de malignidade nos casos de carcinoma de células escamosas de córnea, utilizando o índice mitótico como principal referência. Todas as amostras apresentaram imunomarcação para as proteínas estudadas, porém com intensidade e frequência variadas. Não foi observada relação entre maior índice mitótico e, portanto, maior malignidade, com uma maior expressão de qualquer uma das proteínas analisadas. Conclui-se que a imunoexpressão das proteínas p53, p63 e PUMA estão presentes nos CCE corneal de cães podendo contribuir para sua carcinogênese, mas não fornece indicadores de prognóstico nesta neoplasia
Abstract: Ocular tumors play an increasing concern in veterinary ophthalmology. Corneal squamous cell carcinoma (SCC) is unfrequent in dogs, and by this way it has little studies, and the investigations of carcinogenesis mechanisms are rare. The aim of this work was to identify the p53, p63 and PUMA proteins expression in the spontaneous dog corneal SCC. For this work, were used five cases of corneal SCC and one case of actinic keratitis and their possible contributions to prognosis and therapy. The immunohistochemical analysis could evaluated the number of stained cells by field in optic microscopy using two classifications methods: intensity and immunofrequency. Also, we could evaluated histological grade of tumor related to malignancy in corneal SCC cells by using the mitotic index as a pattern. All samples showed immunolabelling to those proteins studied, although with diversity in intensity and frequency. The authors couldn't observe relationship between the biggest mitotic index, and, by this way, most malignancy, with the expressions of all analysed proteins. These results could support the conclusions that p53, p63 and PUMA proteins immunoexpression are present in canine corneal SCC and could give help to their carcinogenesis, but they don't give a prognostic indicator of these tumors
Mestre

APA, Harvard, Vancouver, ISO, and other styles

7

Cossi, Lucas Bahdour [UNESP]. "Detecção das proteínas p53, p63 e puma no carcinoma de células escamosas corneal de cães: Lucas Bahdour Cossi. -." Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/92182.

Full text

Abstract:

Made available in DSpace on 2014-06-11T19:25:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-12-20Bitstream added on 2014-06-13T20:53:45Z : No. of bitstreams: 1 000739583.pdf: 1703307 bytes, checksum: 8c02eba2666e577572e313859a482bfa (MD5)
Ocular tumors play an increasing concern in veterinary ophthalmology. Corneal squamous cell carcinoma (SCC) is unfrequent in dogs, and by this way it has little studies, and the investigations of carcinogenesis mechanisms are rare. The aim of this work was to identify the p53, p63 and PUMA proteins expression in the spontaneous dog corneal SCC. For this work, were used five cases of corneal SCC and one case of actinic keratitis and their possible contributions to prognosis and therapy. The immunohistochemical analysis could evaluated the number of stained cells by field in optic microscopy using two classifications methods: intensity and immunofrequency. Also, we could evaluated histological grade of tumor related to malignancy in corneal SCC cells by using the mitotic index as a pattern. All samples showed immunolabelling to those proteins studied, although with diversity in intensity and frequency. The authors couldn´t observe relationship between the biggest mitotic index, and, by this way, most malignancy, with the expressions of all analysed proteins. These results could support the conclusions that p53, p63 and PUMA proteins immunoexpression are present in canine corneal SCC and could give help to their carcinogenesis, but they don´t give a prognostic indicator of these tumors

APA, Harvard, Vancouver, ISO, and other styles

8

Chandrachud, Uma. "Differential interaction of wild type and mutant p53 to promoter sequences and analysis of interacting proteins." Diss., Online access via UMI:, 2009.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

9

Hellborg, Fredrik. "Identification, cloning and characterization of the p53 induced gene human wig-1 /." Stockholm, 2004. http://diss.kib.ki.se/2004/91-7140-190-3/.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Lascani, Monsalve Jorge Andrés. "Producción recombinante de péptidos con potencial terapéutico en Escherichia coli." Tesis, Universidad de Chile, 2014. http://repositorio.uchile.cl/handle/2250/131760.

Full text

Abstract:

Magíster en Ciencias de la Ingeniería, Mención Química
Ingeniero Civil en Biotecnología
Durante las últimas décadas, una rama de la investigación biotecnológica se ha enfocado en desarrollar y optimizar procesos de producción de proteínas recombinantes orientadas a aplicaciones terapéuticas. En particular, los péptidos terapéuticos ofrecen actualmente un nuevo potencial comercial para la industria farmacéutica y biotecnológica al generar estrategias efectivas en el tratamiento de diversas patologías como cáncer y alteraciones metabólicas entre otras. Estudios previos han demostrado la capacidad supresora de tumores de péptidos con blanco intracelular como p53p-Ant y PNC-27. Estos corresponden a regiones derivadas de la proteína p53, factor de regulación transcripcional que inhibe la progresión del ciclo celular e induce reparación celular o apoptosis, en caso de estrés genotóxico. Ambos péptidos contienen en su secuencia, un péptido de penetración celular, el cual les entrega la capacidad de atravesar la membrana plasmática. Así, bajo distintos mecanismos, con p53p-Ant y PNC-27 se ha reportado apoptosis o bien necrosis de manera selectiva en ciertos tipos de células tumorales. El presente trabajo tuvo por objetivo expresar en E. coli los péptidos p53p-Ant y PNC-27, y purificarlos mediante el sistema IMPACT. Éste es un mecanismo de expresión y purificación mediado por inteínas que permite purificar a través de una columna de afinidad, proteínas recombinantes con su secuencia nativa sin el uso de proteasas y minimizando pasos cromatográficos. Se logró producir ambos péptidos en forma soluble. La expresión soluble del péptido PNC-27 se consiguió a partir de los dos vectores de expresión proporcionados por el sistema IMPACT (pTXB1 y pTYB11), esta expresión resultó ser fuertemente dependiente de las condiciones de cultivo ya que se requiere de una inducción a baja temperatura (12 °C). Por su parte, la expresión soluble de p53p-Ant depende tanto del sistema de expresión como de las condiciones de cultivo. El diseño de las construcciones genéticas, en particular las que incluyen el vector de expresión pTYB11, permitió una efectiva purificación de los péptidos utilizando un único paso cromatográfico. Más aún, los niveles de rendimiento (0,4 1,2 mg L-1) superan los reportados para péptidos con el mismo sistema y los niveles de pureza obtenidos permitirían desarrollar investigación avanzada con ensayos biológicos in vivo o in vitro.

APA, Harvard, Vancouver, ISO, and other styles

11

Paula, Ana Carolina Barbosa de [UNESP]. "Imunomarcação de proteínas de estresse (HSP 27, HSP 72, HSP 90) e proteína P53 em neoplasias mamárias de cadelas." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/95943.

Full text

Abstract:

Made available in DSpace on 2014-06-11T19:27:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-01-28Bitstream added on 2014-06-13T19:57:04Z : No. of bitstreams: 1 paula_acb_me_jabo.pdf: 945268 bytes, checksum: 8488b75c904e7af7b9e65ce5c9db72e1 (MD5)
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Os tumores de mama são a principal causa de morte em cães e isso vem despertando maior interesse no desenvolvimento de estudos relacionados a este distúrbio. A proximidade com os seres humanos, tanto na convivência quanto aos hábitos, podem influenciar o aparecimento das neoplasias. A semelhança dos tumores mamários caninos com os tumores de mama da mulher leva a um interesse no estudo da patologia comparada, estimulando o uso de modelos animais. Apesar dos muitos estudos, pouco se conhece sobre o prognóstico e as causas dos tumores mamários caninos, observando-se um esforço crescente na tentativa de acrescentar aos fatores prognósticos clássicos novos parâmetros, de natureza molecular, que auxiliem a decisão clínica, à semelhança do verificado em Medicina Humana, estando entre eles os marcadores moleculares, como a proteína P53 e as proteínas de estresse. A expressão de proteína P53 e das proteínas de estresse tem sido observada em muitas neoplasias, incluindo o câncer de mama. Nesse sentido, o objetivo do presente estudo foi investigar a imunomarcação de HSP 27, HSP 72, HSP 90 e proteína P53 em tecido mamário normal e neoplásico de cadelas e estabelecer uma relação entre a expressão destas proteínas e o grau histológico das neoplasias. Foi realizada análise estatística e o nível de significância (α) adotado foi de 5%. Dentre os tumores malignos, os carcinomas simples foram o tipo histológico predominante. Para a proteína P53, não houve diferença significativa em sua expressão entre os grupos de tumores malignos avaliados, ocorrendo o mesmo para as HSPs 27, 72 e 90. A sensibilidade do teste de imuno-histoquímica para a proteína P53, nesta amostra, foi de 67,5%, a especificidade foi de 100%, o valor preditivo positivo foi de 100%, o valor preditivo negativo foi de 25% e acurácia do teste foi de 92%. Ainda para a proteína P53, comparando-se o grupo...
Breast tumors are the leading cause of death in dogs and this has aroused great interest in developing studies related to this disease. The proximity with humans, much as in living habits, may influence the onset of tumors. The similarity of canine mammary tumors with breast tumors of women take an interest in the study of comparative pathology, stimulating the use of animal models. Despite many studies, little is known about the prognosis and causes of canine mammary tumors, observing a growing effort in trying to add to the classic prognostic factors new parameters of molecular nature, that help the clinical decision, like that seen in Human Medicine, and among them the molecular markers such as P53 and stress proteins. The expression of P53 protein and the stress proteins has been observed in many cancers, including breast cancer. Accordingly, the purpose of this study was to investigate the immunostaining of HSP 27, HSP 72, HSP 90 and P53 protein in normal and neoplastic breast tissue of female dogs and establish a relationship between the expression of these proteins and the histological grade of tumors. Statistical analysis was performed and significance level (α) was 5%. Among the malignant tumors, simple carcinomas were the predominant histologic type. Protein P53, presented no significant difference in expression between the evaluated groups of malignant tumors, the same occurring for HSPs 27, 72 and 90. The test sensitivity of immunohistochemistry for protein P53 in this sample was 67,5%, specificity was 100%, positive predictive value was 100%, negative predictive value was 25% and accuracy of test was 92%. Although protein P53, compared to the control group with other groups in relation to staining intensity and proportion score, there was a significant difference only between the group of simple carcinomas. With regard to staining intensity, we tested the correlation between... (Complete abstract click electronic access below)

APA, Harvard, Vancouver, ISO, and other styles

12

Pozniak, Christine D. "The related p53 and p73 proteins have opposing roles in neuronal survival and apoptosis /." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=38259.

Full text

Abstract:

The neurotrophins support survival of many different classes of neurons during development of the nervous system. Appropriate neuronal numbers are generated as developing neurons compete for adequate amounts of neurotrophin and those that are unsuccessful die by a process of apoptosis. In addition to survival, the neurotrophins have recently been shown to regulate apoptosis by activating the p75 neurotrophin receptor at the cell surface. Therefore, the decision to live or die depends on the interplay between survival and death signals, but the underlying mechanisms mediating these events are only beginning to be elucidated. The following chapters highlight the function of two related proteins, p53 and p73, and their opposing roles in neuronal apoptosis and survival.
The first chapter demonstrates that the endogenous p53 tumor suppressor protein is essential for naturally occurring death of sympathetic neurons. Blocking the function of p53 either by targeted deletion in mice or viral inhibitors can rescue sympathetic neurons from apoptosis. These results are consistent with the role of p53 following injury in postmitotic neurons, however, they also demonstrate a novel function for p53 during nervous system development.
The next experiments define a role for the p53 related protein, p73, in sympathetic neuron development. P73 exists as both pro and anti-apoptotic isoforms with the latter being predominantly expressed in the nervous system. Here I report that the anti-apoptotic p73 protein (DeltaNp73) is essential for sympathetic neuron survival during development and that one of its main targets is p53.
The final section examines the role of DeltaNp73 in the CNS. Cortical neurons die at a rapid and continuous rate in the absence of DeltaNp73. We also identify p73 at a position downstream of PI3 kinase, a major survival protein important for many types of neurons. Finally, we demonstrate that p73 overexpression can protect neurons from DNA damage induced death.
Together these studies have identified novel and opposing roles for the p53 family members in developing and mature neurons of the central and peripheral nervous systems.

APA, Harvard, Vancouver, ISO, and other styles

13

Lu, Wenjing, and 鲁文静. "The interaction of mortalin and p53 in human hepatocellular carcinoma." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B46330069.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Harms, Kelly Lynn. "Mechanisms of P53-mediated apoptosis." Thesis, Birmingham, Ala. : University of Alabama at Birmingham, 2007. https://www.mhsl.uab.edu/dt/2009r/harms.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Pei, Lim-cho Steven, and 貝念祖. "Role(s) of p53/p63 in chondrocyte re-differentiation upon activation of ER stress." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hdl.handle.net/10722/198926.

Full text

Abstract:

Endoplasmic Reticulum (ER) stress signal is a cellular response to various insults including abnormal protein folding load, activating the unfolded protein response. Under severe ER stress, apoptosis will occur in most cell types. Interestingly, this does not happen in a disease model for Metaphyseal chondrodysplasia type Schmid (MCDS), where ER stress was activated in the hypertrophic zone of the growth plate where mutant collagen X proteins that cannot be folded correctly is expressed. Instead of normal progression from proliferating chondrocytes (PCs) to hypertrophic chondrocytes (HCs) and conversion to bone, HCs in MCDS mice undergo re-differentiation to PCs as a survival strategy due to an activation of ER stress. Transcription factors are known to be important in regulating differentiation. p53 family members, as transcription factors, are known to play important roles in developmental processes including cellular reprogramming, thus, we hypothesize that the ectopic expression of key transcription factors, p53 and TAp63, which are activated by ER stress is involved in HC re-differentiation. p53 is normally expressed in late PCs, Pre-HCs, and upper HCs, while TAp63 is expressed in PCs and Pre-HCs suggesting they may have roles in chondrocyte differentiation. p53 activated under ER stress in HCs are nuclear localized in MCDS mice, but did not invoke the apoptotic programme. In this project, using quantitative analyse to study the expression level of p53 and p63 isoforms, it was confirmed that p53 and TAp63γ are in part transcriptionally activated upon ER stress. From functional study by inactivating p53 in MCDS mice, it was shown that p53 alone was not sufficient to mediate re-differentiation. Given that TAp63γ isoforms is also highly upregulated upon ER stress, and the negative regulator, ΔNp63, is downregulated, this combination of change in gene expression also need to be considered. Furthermore, known regulators of p53 and p63 activity such as ASPP1 and iASPP are also differentially expressed in HCs, and are altered upon activation of ER stress favouring cell survival. Thus, it would be important to evaluate the combination of TAp63 in the re-differentiation process from conditional inactivation of p63 or in combination with p53 to gain a clearer understanding of the contribution and relationship of these transcription factors in the survival strategy of stressed HCs.
published_or_final_version
Biochemistry
Master
Master of Philosophy

APA, Harvard, Vancouver, ISO, and other styles

16

Saidj, Djamel. "Alteration of p53 and NF-kB pathways by E7 protein from cutaneous Human Papillomavirus type 38." Thesis, Lyon 1, 2013. http://www.theses.fr/2013LYO10237/document.

Full text

Abstract:

Les infections virales sont responsables de 15 à 20 % des cancers humains. L étude des mécanismes moléculaires avec lesquels les virus oncogènes induisent la transformation cellulaire est essentielle pour la compréhension des cancers qui en résultent. Cela permettra également la découverte de nouveaux mécanismes pouvant être impliqués dans le développement de cancers, qui peuvent être ciblés par des approches thérapeutiques. Les virus du papillome humain (HPV) sont des petit virus à ADN qui futs isolés de la peau de patients souffrants de Epidermodysplasia Verruciformis (EV) qui cause un risque élevé d'infection par les HPV et le développement de cancer de la peau non mélanique (NMSC). Certains HPV cutanés, tels que HPV5, 8 et 38, sont suspectés de jouer un rôle dans de développement du cancer de la peau. Cependant, le lien direct entre les HPV cutanés et l'étiologie du cancer n'est pas encore clairement établi. Des études de notre laboratoire ont montré que les oncoprotéines HPV38 E6 et E7 sont capables d'immortaliser des kératinocytes primaires humains in vitro et in vivo. Pour immortaliser des cellules, d'importantes voies de signalisations, telles que les voies de p53 et celle de NF-KB, doivent être affectées. Dans cette étude, nous avons cherché à mettre en évidence les mécanismes moléculaires menant à la dérégulation de p53 et de NF-KB par E6 et E7 de HPV38, dans des kératinocytes humains. Nous avons montré que HPV38 E6 et E7 induisent la formation d'un complexe protéique incluant IKKβ, ΔNp73α, EZH2 et DNMT1. La formation de ce groupement protéique corrèle avec l'inhibition de la transcription de certains gènes cibles de p53, tel que PIG3. Nous avons également mis en évidence l'activation de la voie NF-KB par les oncoprotéins E6 et E7 de HPV38. Cette activation est importante par le rôle joué par NF-KB dans la protection des cellules de l apoptose induite par TNF-α et par l'exposition aux rayonnements UVB. De plus nous avons observé que E7 est la principale oncoprotéine de HPV38 responsable de la dérégulation des voies p53 et NF-KB. Nos études mettent en évidence de nouveaux mécanismes moléculaires qui peuvent être essentiels dans le processus de transformation cellulaire par HPV38
Viral infections contribute to 15–20% of all human cancers. Studying the mechanisms employed by the oncogenic viruses to induce cellular transformation is essential for a better understanding of the resulting cancers and the discovery of new mechanisms involved in cancer development which can be targeted in therapeutic approaches. Human papillomaviruses (HPVs) are small dsDNA viruses which have been clearly associated with certain cancers. They were first isolated from the skin of patients suffering from Epidermodysplasia Verruciformis (EV) having an increased susceptibility to infection by specific HPV types and to the development of non-melanoma skin cancer (NMSC). Certain cutaneous HPV types, such as 5, 8, and 38, are suspected to play a role in skin cancer development. However the direct role of cutaneous HPV in the etiology of cancer is still under debate. Previous studies from our laboratory have reported that HPV38 E6 and E7 proteins are able to immortalize human primary keratinocytes in vitro and in vivo. Cellular immortalization can be achieved through the deregulation of important signaling pathways including p53 and NF-KB. In the present work, we have investigated the molecular mechanisms of p53 and NF-KB pathways deregulation by E6 and E7 oncoproteins from HPV38 in human keratinocytes. We show here that HPV38 E6E7 induce the formation of a transcription repressor complex including IKKβ, ΔNp73α, and polycomb group members EZH2 and DNMT1. The formation of this protein complex correlates with the inhibition of several p53-target genes, such as PIG3. We also report in these studies that HPV38 E6E7 activate NF KB pathway, which plays an important role in the survival of HPV38 E6E7-immortalized human keratinocytes upon TNF-α– and UVB-mediated apoptosis. In addition our data highlight E7 being the main HPV38 protein mediating p53 and NF-KB deregulation. Our studies shed light on novel molecular mechanisms that could be important for HPV38-mediated cellular transformation

APA, Harvard, Vancouver, ISO, and other styles

17

Coelho, Guilherme Portela. "Relação entre os critérios diagnósticos histológicos e a expressão imuno-histoquímica da P53 no carcinoma prostático." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2005. http://hdl.handle.net/10183/5833.

Full text

Abstract:

Introdução e Objetivo: o gene TP53 é o alvo isoladamente mais comum de mutação em tumores humanos. Está envolvido no bloqueio do ciclo celular, reparo ao DNA, diferenciação celular e apoptose, em resposta ao dano genético. O exame de imuno-histoquímica (IHQ) pode detectar o acúmulo da proteína p53 no núcleo celular, indicando mutação. Esta mutação tem sido associada a comportamento agressivo nos carcinomas prostáticos. O conhecimento das características histológicas deste carcinoma permite o estabelecimento de critérios diagnósticos anatomopatológicos e de graduações histológicas que visam a um melhor atendimento dos pacientes com a doença. O estudo da relação entre os achados de biologia molecular e as características histológicas desta neoplasia leva a um maior conhecimento de mecanismos que produzem as alterações morfológicas teciduais, auxiliando na identificação de novas variáveis promissoras na determinação do comportamento biológico da doença. Material e Método: foram examinadas amostras de 101 exames de biópsias por agulha da próstata, de setenta pacientes com carcinoma, através de lâminas coradas pelo HE, selecionados de 500 exames consecutivos. Obtiveram-se novos cortes dos mesmos blocos de parafina, sendo estes corados pela técnica de IHQ, utilizando o anticorpo monoclonal DO7 para p53, em 69 dos pacientes. Foram anotados, para estudo de associação, os achados morfológicos de carcinoma, o padrão da coloração IHQ para p53, a presença de invasão de nervos (IN) pelas colorações HE e de IHQ para proteína S100 e algumas características clínico-laboratoriais dos pacientes com carcinoma prostático. Resultados: dentre as formas de aferir a positividade IHQ da p53, a imunorreatividade em grupamento foi o padrão que melhor se correlacionou com os achados clínico-patológicos examinados: PSA sérico, escore de Gleason, quantidade de tumor na amostra (p<0,01) e presença de invasão de nervo. Dentre os critérios diagnósticos estudados, houve associação estatisticamente significativa da imunorreatividade em grupamento para p53 com as presenças de micronódulos de colágeno e mais de um nucléolo proeminente no mesmo núcleo de célula neoplásica. Quanto à IN, apenas quando a mesma foi identificada com a técnica de IHQ (proteína S100), houve associação estatisticamente significativa. Conclusão: o padrão de imunorreatividade em grupamento mostra-se superior aos demais quando comparado aos achados anatomopatológicos com valor preditivo em biópsias e com o valor do PSA sérico. A associação estatisticamente significativa entre a imunorreatividade em grupamento para p53 e a presença de IN detectada com a utilização da proteína S100 contrasta com a ausência de significância quando a IN é identificada na histologia convencional (HE). Estes achados recomendam novos estudos para verificar a utilidade da determinação IHQ da IN no prognóstico da doença e para identificar o mecanismo molecular de invasão de nervos de pequeno tamanho que não são facilmente identificados no HE. A presença da associação da positividade IHQ para p53 com micronódulos de colágeno igualmente recomenda novos estudos clínicos e moleculares para esclarecimento da relação deste achado histológico com o comportamento biológico do carcinoma prostático.

APA, Harvard, Vancouver, ISO, and other styles

18

Gaido, Nadja Cruz. "Análise da expressão proteica da P53 em adenomas hipofisários." Universidade Federal do Maranhão, 2016. http://tedebc.ufma.br:8080/jspui/handle/tede/1426.

Full text

Abstract:

Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-05-17T21:24:47Z No. of bitstreams: 1 NadjaCruzGaido.pdf: 2766927 bytes, checksum: 6fdfd1a4a2beb11f1da8d3669b11750a (MD5)
Made available in DSpace on 2017-05-17T21:24:47Z (GMT). No. of bitstreams: 1 NadjaCruzGaido.pdf: 2766927 bytes, checksum: 6fdfd1a4a2beb11f1da8d3669b11750a (MD5) Previous issue date: 2016-09-30
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Fundação de Amparo à Pesquisa e ao Desenvolvimento Científico e Tecnológico do Maranhão (FAPEMA)
The pituitary adenomas represent about 10 to 15% of intracranial tumors and are usually benign, comprising a cell population of monoclonal origin. They are classified as macroscopic and radiological aspects, functional status, dyeing, immunohistochemistry and microscopic. About 70% of human cancers have mainly a deficiency in the function gene. The p53 gene is extensively studied in tumors, showing that patients with mutations have a worse prognosis, as well, the p53 protein is critical in preventing tumor development performing change detection function in DNA and thereby fix or apoptosis. It is possible that the increase in expression of this protein is the result of an attempt to stop the cell cycle in response to deregulation by a stimulus from another source. This way, the study seeks to determine the expression of p53 protein in pituitary adenomas. an analytical study, with crosssectional was held in which were included 62 patients older than 16 years of both sexes, who were diagnosed with pituitary adenoma, from 2008 to 2016, arising from the Endocrinology Service University hospital of the Federal University of Maranhão - HUUFMA. These patients underwent surgical resection of the tumor, obtaining the samples of tumor tissue. After conventional histopathology, they were embedded in paraffin, for carrying out the immuno-histoqumico study aimed to identify the expression of p53 protein and implications correlated with biological behavior of pituitary adenomas. The analysis for p53 protein expression in adenomas was obtained by immunoenzymatic of streptoavidin-biotin or immunohistochemistry. The p53 protein immunostaining revealed no statistically significant correlation, as the clinical and demographic characteristics such as gender, age, p53 expression in tumor subtypes and tumor volume. It is necessary to obtain greater numbers of patients, so that p53 expression is effective when the real prognostic value in pituitary adenomas.
Os adenomas hipófisários representam cerca de 10 a 15% das neoplasias intracranianas e são geralmente benignos e compostos por uma população celular de origem monoclonal. São classificados conforme aspectos macroscópicos e radiológicos, status funcional, tintoriais, imuno-histoquímica e microscópicas. Cerca de 70% dos cânceres humanos possuem principalmente uma deficiência na função do gene. O gene p53 é extensivamente estudado nas neoplasias mostrando que pacientes com mutações apresentam um pior prognóstico, assim, a proteína p53 é fundamental na prevenção do desenvolvimento de tumores exercendo a função de detecção de alterações no DNA e, consequentemente, correção ou apoptose. É possível que o aumento na expressão desta proteína seja decorrente de uma tentativa de frear o ciclo celular como resposta à desregulação por um estímulo de outra origem. Dessa forma, o estudo busca avaliar a imunoexpressão da proteína p53 em adenomas hipofisários. Foi realizado um estudo analítico com delineamento do tipo transversal, no qual foram incluídos 62 pacientes com idade superior 16 anos de ambos os sexos, que apresentaram diagnóstico de adenoma hipofisário no período de 2008 a 2016, oriundos do Serviço de Endocrinologia do Hospital Universitário da Universidade Federal do Maranhão – HUUFMA. Esses pacientes foram submetidos à ressecção cirúrgica do tumor, com obtenção das amostras do tecido tumoral. Após diagnóstico histopatológico convencional, foram emblocadas em parafina, para realização do estudo imuno-histoqumico com o objetivo de identificar a imunoexpressão para proteína p53 e implicações correlacionadas ao comportamento biológico dos adenomas hipofisários. A análise para expressão da proteína p53 em adenomas hipofisários foi obtida através da reação imunoenzimática da streptoavidina-biotina-peroxidase ou imuno-histoquimica. A imunoexpressão da proteína p53 não revelou correlação estatisticamente significante, quanto aos achados clínicos e características demográficas, tais como sexo, idade, imunoexpressão da p53 para os subtipos tumorais e volume tumoral. Torna-se necessário obter números mais expressivos de pacientes para que a imunoexpressão da p53 seja efetiva, quanto ao real valor prognóstico em adenomas hipofisários.

APA, Harvard, Vancouver, ISO, and other styles

19

Radakovič, Jozef. "Predikce vazebních míst proteinu p53." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2015. http://www.nusl.cz/ntk/nusl-234992.

Full text

Abstract:

Protein p53 which is encoded by gene TP53 plays crucial role in cell cycle as a regulator of transcription of genes in cases when cell is under stress. Therefore p53 acts like tumor suppressor. Understanding the pathway of p53 regulation as well as predicting its binding sites on p53 regulated genes is one of the major concerns of modern research in genetics and bioinformatics. In first part of this project we aim to introduce basics from molecular biology to better understand the p53 protein pathway in gene transcription and introduction to analysis of prediction of p53 binding sites. Second part is about implementation and testing of tool which would be able to predict transcription factor binding sites for protein p53.

APA, Harvard, Vancouver, ISO, and other styles

20

Teixeira, Roberto Augusto Plaza. ""Fatores clínicos e biológicos para recidivas em tumores de Wilms localizados"." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/5/5141/tde-04012006-105538/.

Full text

Abstract:

Apesar do excelente prognóstico dos tumores de Wilms (TW) localizados (estádios I e II) e de histologia favorável (HF), 10% deles recidivam. Em 122 pacientes com TW com essas características, diagnosticados de 1976 e 2001, analisamos alguns fatores clínicos, como a idade por ocasião do diagnóstico e peso do tumor, em todos os pacientes; fatores biológicos, como o TP53 e a glicoproteína-p, em 40 deles; e variáveis histológicas de microestadiamento (invasão de seio renal, cápsula tumoral, vasos intra-renais e pseudocápsula inflamatória) em 28 com TW em estádio I. Correlacionando todos esses fatores com a presença de recidiva, observamos que a chance maior de recidiva estatisticamente significativa somente foi verificada em pacientes com duas ou mais variáveis de microestadiamento e/ou peso tumoral maior que 550 g
In spite of the excellent prognosis of localized favorable histology (FH) of Wilms' tumor (WT), 10% of them will relapse. In 122 TW patients with these characteristics, diagnosed between 1976 and 2001, some clinical factors have been analyzed, such as age at diagnosis and tumor weight in all patients; biological factors, like TP53 and p-glycoprotein, in 40 of them; and microsubstaging histological variables (invasion of renal sinus, tumor capsule, intrarenal vessels, and inflammatory pseudocapsule). Correlating all of those factors with relapse, we have observed that only patients with the association of two or more microsubstaging variables and/or tumor weight over 550 g showed a statistically significant higher chance of relapse

APA, Harvard, Vancouver, ISO, and other styles

21

Ndabambi, Nonkululeko. "Recombinant expression of the pRb- and p53-interacting domains from the human RBBP6 protein for in vitro binding studies." Thesis, University of the Western Cape, 2004. http://etd.uwc.ac.za/index.php?module=etd&amp.

Full text

Abstract:

The aim of this thesis was to produce DNA expression constructs and use them to investigate the feasibility of recombinantly expression proteins for future interaction studies between human RBBP6 and p53 and pRb proteins.

APA, Harvard, Vancouver, ISO, and other styles

22

Tweddle, Deborah Anne. "The role of p53 and p53 regulated proteins in neuroblastoma." Thesis, University of Newcastle Upon Tyne, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246680.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

Méndez, Vidal Cristina. "Molecular studies of WIG-1, A P53-induced zinc finger protein /." Stockholm, 2003. http://diss.kib.ki.se/2003/91-7349-732-0.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Silva, Lara Marques Loureiro. "ASPP2 regulating p63/p73 and Notch pathways in tumourigenesis." Master's thesis, Universidade de Aveiro, 2012. http://hdl.handle.net/10773/10878.

Full text

Abstract:

Mestrado em Biotecnologia Molecular
Na pele surgem dois dos tipos mais comuns de cancro epitelial, o carcinoma basocelular (BCC) e o carcinoma escamoso da pele (SCC). Neste trabalho, investigámos como ASPP2, membro da família de proteínas que interage com a família p53, pode afectar a tumurigénese da pele. Estudou-se a regulação por ASPP2 das vias de sinalização envolvidas na homeostasia normal do tecido epitelial, tais como as vias de p63 e Notch. A activação anormal de ΔNp63 no epitélio é uma causa conhecida para o surgimento do SCC e os nossos resultados indicam que a ASPP2 é importante a limitar a expressão de ΔNp63 no epitélio diferenciado, prevenindo a proliferação das células na pele. Para além disso, observámos que ASPP2 coopera com vias de sinalização pró-diferenciação, tais como as de Notch e p73. Os nossos resultados mostram um possível mecanismo pelo qual a expressão de p63 pode ser regulada na pele e sugerem um novo modelo para a formação espontânea de SCC.
The skin is where two of the most common types of epithelial cancer, basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), arise. In this work, we have investigated how ASPP2, a member of a family of proteins that interact with the p53 family, can affect skin tumourigenesis. We analysed the regulation of ASPP2 in pathways involved in the normal homeostasis of the epithelium, such as the p63 and Notch. Aberrant or misplaced activation of ΔNp63 in the epithelium is a known initiating cause for SCC and our results indicate that ASPP2 is important in limiting ΔNp63 expression in the differentiated epithelium, preventing cell proliferation in the skin. Additionally, we found that ASPP2 can cooperate with skin pro-differentiation pathways, such as Notch and p73. Overall, our results indicate a possible mechanism by which p63 expression can be regulated in the skin, and provide a new model for the spontaneous formation of SCC.

APA, Harvard, Vancouver, ISO, and other styles

25

Goffin, Sarah Anne. "Targeting the p53/MDM2 protein-protein interaction." Thesis, University of East Anglia, 2016. https://ueaeprints.uea.ac.uk/57422/.

Full text

Abstract:

The p53/MDM2 protein-protein interaction is the most widely characterised proteinprotein interaction to date. As of 2014, there are over 20 compounds that have been shown to the p53-MDM2 protein-protein interaction, however many compounds have not progressed into clinical trials due to their high hydrophobicity. Herein we describe the synthesis, molecular modelling, physical characterisation and biological testing of novel inhibitors of the p53/MDM2 protein-protein interaction based on the natural product chlorofusin. The first focus is a combinatorial library generated in the Searcey laboratory of known p53/MDM2 protein-protein interaction inhibitors with the desire to generate novel analogues and study their interactions with the protein through NMR spectroscopy and molecular modelling. These compounds were tested by in a fluorescence polarisation assay and also in cell lines overexpressing MDM2 as well as p53-null cells as a comparator. This generated two novel compounds shown to have activity selectively for the p53/MDM2 protein-protein interaction. The second chapter focuses on simplified substitutions of the azaphilone (the chromophore portion of chlorofusin, a natural product inhibitor of the p53-MDM2 proteinprotein interaction): initially with simple fused bicyclic carboxylic acids and later using click chemistry substitutions. Interestingly, in vitro studies showed that the click analogues retained activity or activity improved when the peptide portion was removed and hence further studies of the click amino acid analogues were generated. This library generated one analogue that was active in vitro as well as selectively in MDM2-overexpressing cell lines. The third chapter focusses on the azaphilone chromophore present in the natural product chlorofusin. The Sonogashira precursor used to generate azaphilone analogues was synthesised using a methodology adopted by Porco et al and subsequent analogues were generated using a novel double-Sonogashira approach followed by functionalisation published by Boger et al. Once the azaphilone was synthesised, metholodogies were trialled in order to condense the azaphilone with the chlorofusin peptide in order to create analogues containing both the peptide and small molecule portions of chlorofusin. In addition, molecular modelling was attempted to generate novel binding analogues.

APA, Harvard, Vancouver, ISO, and other styles

26

CAVALCANTI, Mariana Brayner. "Proteína p53 como bioindicador da radiossensibilidade individual." Universidade Federal de Pernambuco, 2009. https://repositorio.ufpe.br/handle/123456789/9206.

Full text

Abstract:

Made available in DSpace on 2014-06-12T23:13:38Z (GMT). No. of bitstreams: 2 arquivo2653_1.pdf: 3219087 bytes, checksum: e49263700ce90bf224851971f1039607 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2009
Conselho Nacional de Desenvolvimento Científico e Tecnológico
A radiossensibilidade celular está diretamente relacionada às falhas no mecanismo de reparo dos danos causados ao DNA. Nesse mecanismo, a molécula considerada como chave é a proteína p53. Neste contexto, o objetivo desta pesquisa foi avaliar a correlação entre os níveis de expressão da proteína p53 com a radiossensibilidade individual. Para tanto, amostras de sangue periférico de 23 indivíduos sadios foram divididas em alíquotas e, separadamente, irradiadas com doses de 0,5; 1; 2 e 4 Gy. Em seguida, células mononucleares do sangue periférico (PBMCs) foram obtidas e cultivadas durante 72 horas, tanto na presença quanto na ausência de mitógenos (Fitohemaglutinina PHA e Pokeweed PKW). Em paralelo, a viabilidade celular foi determinada utilizando o corante azul de trypan (0,4%). Os resultados obtidos demonstraram que a expressão da proteína p53 em PBMCs aumenta com a dose absorvida sendo inversamente proporcional à viabilidade celular. O maior índice da expressão de p53 foi observado em culturas estimuladas com PHA durante 72 horas. O aumento na expressão da p53, em resposta à radiação, foi significativamente diferente entre os indivíduos estudados, o que pode ser relacionado a variabilidade na radiossensibilidade individual. Os resultados desse trabalho sugerem estudos adicionais no sentido de correlacionar os níveis de expressão de p53 com efeitos adversos graves em pacientes submetidos à radioterapia

APA, Harvard, Vancouver, ISO, and other styles

27

Johnson, Jodi L. "The p53 family interacting pathways in carcinogenesis and cellular response to DNA damage." Oregon Health & Science University, 2007. http://content.ohsu.edu/u?/etd,628.

Full text

Abstract:

Ph.D.
Molecular and Medical Genetics
The objective of this study is to examine, in light of the expression of multiple p53 family member isoforms, the specific role of p73 in malignant conversion, cellular response to DNA damage, and direct or indirect cooperation with other p53 family members in a clonal model of epidermal carcinogenesis. We first focused on the role of p73 in malignant conversion. Whether sporadic or siRNA induced, loss of p73 in initiated p53+/+ keratinocytes lead to conversion to squamous cell carcinoma (SCC) in vivo which was reversible upon reconstitution of TAp73α but not ΔNp73α. Second, we investigated the cellular response to ionizing radiation (IR) in the presence and absence of p73, showing that loss of p73 at malignant conversion was associated with resistance to IR in vitro. The loss of radiation sensitivity and malignant conversion was characterized by reduced steady state DNA binding levels of transcriptionally active p63 isoforms to the p21 promoter, failure to induce specific p53 family transcriptional targets, and failure to arrest in G1. Reconstitution of TAp73α, but not ΔNp73α, increased steady state DNA binding capabilities of TAp63β, TAp63γ, and ΔNp63γ, and steady state levels of p53 family target mRNA, but did not restore cellular sensitivity to IR. We thus uncovered a functional cooperation between TA isoforms of p73 and p63 and showed that p73-mediated DNA damage response was uncoupled from its tumor suppressive role. We observed preferential DNA binding of the inhibitory ΔNp63α isoform both in vitro and invivo in SCC suggesting that in the absence of TAp73α a balance is tipped toward DNA binding of the inhibitory isoforms. Third, we studied the role of the p53 family inkeratinocyte response to UVB. Tumorigenic cells lacking p73 that were resistant to IR remained sensitive to UVB, accompanied by DNA binding of the TAp63γ isoform, suggesting that keratinocyte response to UVB is not dependent upon p73 and suggesting a hierarchy of p53 family member responses to DNA damage. Finally, we examined TAp73α interaction with the p53 family inhibitor Mdm2. Mdm2 was in complex with DNA-bound p53 family members in malignant cells, but reconstitution of cells withTAp73α correlated with removal of Mdm2 from the complex, making them more like primary keratinocytes or initiated cells. Like the initiated cells, cells expressing TAp73α were refractory to treatment with the Mdm2-p53 inhibitor Nutlin-3 while cells lacking p73 expression or expressing ΔNp73α were sensitive. Thus, we suggest that p73 may be acting as a molecular shield to keep p53 family member inhibitors, such as ΔNp63α andMdm2, at bay. Further understanding of p53 family interplay in tumor development and DNA damage response could lead to new therapies or optimization of current therapeutic strategies in solid tumors of epithelium, particularly where deregulation or loss of p63 and p73 expression is associated with increased tumor invasiveness, treatment resistance, and poor patient prognosis.

APA, Harvard, Vancouver, ISO, and other styles

28

Wilhelm, Margareta. "The p53-induced gene wig-1 : regulation of expression and role in embryonic development /." Stockholm, 2003. http://diss.kib.ki.se/2003/91-7349-728-2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Kazlauskas, Arunas. "Regulation of dioxin receptor function by the Hsp90 chaperone complex /." Stockholm, 2002. http://diss.kib.ki.se/2002/91-7349-176-4.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Gilkes, Daniele M. "Multiple modes of MDMX regulation affect p53 activation." [Tampa, Fla.] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002312.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Wang, Qian. "p53 functional loss by mutation and p53 antagonizing proteins during tumor development /." Stockholm, 2000. http://diss.kib.ki.se/2000/20000525wang/.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Chiesa, Joelmir José. "Expressão do gene e da proteína P63 em células da granulosa luteinizadas de pacientes inférteis submetidas a fertilização in vitro." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2015. http://hdl.handle.net/10183/131971.

Full text

Abstract:

Introdução: O gene p63 é o mais ancentral membro dos integrantes da família p53 e é descrito como o responsável pela manutenção da integridade gênica e regulação do ciclo celular em células germinativas imaturas. Porém, ainda não há relatos na literatura que avaliem sua expressão em células da granulosa luteinizadas. A endometriose é uma doença crônica que está associada à infertilidade. Vários mecanismos foram propostos para explicar esta associação, mas, até o momento, nenhum deles é considerado definitivo. Objetivos: O objetivo desse estudo é avaliar a expressão do gene e da proteína p63 em células da granulosa luteinizadas de pacientes inférteis submetidas à fertilização in vitro (IVF). Além disso, verificar se pacientes com endometriose apresentam função anormal da p63. Métodos: Realizamos um estudo transversal e prospectivo. Nós coletamos células da granulosa de 28 pacientes submetidas a IVF para avaliar a expressão de p63. Depois, para estudar o efeito na endometriose dividimos em dois grupos: (1) grupo estudo (n=9): pacientes com diagnóstico videolaparoscópico de endometriose e (2) grupo controle (n=19): pacientes inférteis por outros motivos, sem endometriose. As células coletadas foram preparadas e analisadas para expressão gênica (PCR em tempo real) e expressão proteica (imunofluorescência). Os resultados foram comparados entre os grupos. Resultados: Não observamos diferença significativa de expressão do gene p63 entre os grupos estudados. A mediana do 2-ΔΔCT no grupo controle foi 0,93 (IC 95%, 0,55- 2,83) e 0,88 no grupo em estudo (IC 95%, 0,24-2,84). O resultado também mostrou que o gene p63 não é expresso nos dois grupos. Quanto à expressão da proteína p63, a imunofluorescência não demonstrou expressão em nenhum dos dois grupos. Conclusão: O gene e a proteína p63 podem ser muito importantes na manutenção da integridade gênica de folículos imaturos de reserva, não dependentes de FSH. Porém, após o recrutamento e crescimento folicular, não se observa mais sua expressão, ou seja, ele não faz parte da maturação e desenvolvimento oocitário.
Introduction: The p63 gene is the most ancient member of the components of p53 family and is described as the responsible for maintaining of genic integrity and cell cycle regulation in immature germ cells. However, there are no reports in the literature evaluating its expression in granulosa cells luteinized. Endometriosis is a chronic disease that is associated with infertility. Several mechanisms have been proposed to explain this association, but so far, none of them is considered definitive. Objectives: The purpose of this study is to evaluate the expression of the p63 gene and protein in granulosa luteinized cells of infertile patients undergoing in vitro fertilization (IVF). Also, we checked whether patients with endometriosis have abnormal function of p63. Methods: We performed a prospective cross-sectional study. We collected granulosa cells of 28 patients undergoing IVF to evaluate p63 expression. Then, to study the effect on endometriosis, they were divided into two groups: (1) study group (n = 9): patients with laparoscopic diagnosis of endometriosis and (2) control group (n = 19): infertile patients for other reasons, without endometriosis . The collected cells were prepared and analyzed for gene expression (real time PCR) and protein expression (immunofluorescence). The results were compared between the groups. Results: There was no significant difference in expression of the p63 gene between the groups. The median of 2-ΔΔCT in the the control group was 0.93 (95% CI, 0.55 to 2.83) and 0.88 in the study group (95% CI, 0.24 to 2.84). The results also showed that the p63 gene is not expressed in granulosa cells in both groups. About to the p63 protein expression, immunofluorescence showed no expression in either group. Conclusion: The p63 gene and protein can be very important in maintaining the genic integrity of immature reserve follicles, not dependent of FSH. However, after the recruitment and follicular growth is not more observed its expression, suggesting that p63 is not part of control of oocyte maturation and development.

APA, Harvard, Vancouver, ISO, and other styles

33

Pääjärvi, Gerd. "Xenobiotics-induced phosphorylations of MDM2 /." Stockholm, 2006. http://diss.kib.ki.se/2006/91-7140-951-3/.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Ressio, Rodrigo Albergaria. "Avaliação da imuno-expressão de proteínas da via da apoptose mediadas pela proteína p53 no carcinoma hepatocelular." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/5/5160/tde-03112010-165617/.

Full text

Abstract:

O presente estudo teve por objetivo estudar a participação da apoptose na carcinogênese hepatocelular, quantificando os corpos apoptóticos imunomarcados por caspase-3 clivada em amostras de carcinoma hepatocelular (CHC) em pacientes com ou sem cirrose, comparando também estes achados com amostras correspondentes de fígado não tumoral. Visou também à análise semi-quantitativa da imuno-expressão da proteína p53, Bax e Citocromo-C, relacionadas à via mitocondrial da apoptose em busca de eventuais relações com as variáveis clínicopatológicas dos carcinomas hepatocelulares. A análise comparativa da distribuição das diversas proteínas aqui estudadas foi ainda efetuada, com vistas à possível demonstração de sua interação no processo de apoptose em CHC. Amostras selecionadas de 79 casos de CHC foram distribuídas em micromatriz tecidual e submetidas a pesquisa imuno-histoquímica com amplificação por polímeros curtos de dextran ligados a peroxidase. IA foi maior nos CHC que nas amostras não-neoplásicas, mostrando ainda tendência a associação com o grau histológico do CHC .A imuno-expressão de p53 foi maior nos CHC em fígado cirrótico (CHC-C), em casos com invasão vascular, e nos graus histológicos altos. Houve maior imunoexpressão de citocromo c em CHC-C, sendo importante sua associação com p53. Bax mostrou apenas tendência a associação com o tamanho do CHC. Essas evidências contribuem para a compreensão da importância da via mitocondrial da apoptose mediada pela proteína p53 no CHC, destacando também prováveis diferenças do mecanismo carcinogenético na presença ou não de cirrose
This study aimed at the assesment of aspects of the role of apoptosis in hepatocellular carcinogenesis, quantifying apoptotic bodies immunomarked by cleaved caspase-3 in samples of hepatocellular carcinoma (HCC) in patients with or without cirrhosis, further comparing these findings to those from samples in non-tumoral areas of these livers. We also aimed herein to semiquantitate the immunoexpression of p53, Bax, Cytochrome-C, participants of the mitochondrial pathway of apoptosis, searching for possible relations with clinico-pathological variables in HCC. Samples from 79 cases of HCC were arranged in tissue microarrays were and submitted to immunohistochemical reaction with signal amplification achieved by the short-polymer-peroxidase system. Apoptotic index measured by immunoexpression of cleaved-caspase 3 was higher in HCC than in samples from non-neoplastic areas. p53 immunoexpression was higher in HCC occurring in cirrhotic livers, (HCC-C), in cases with vascular invasion and in higher histological grades. Cytochrome-c immunoexpression was also higher in HCC-C and, interestingly, was directly related to p53. Bax immunoreactivity showed only a trend for a relation with the size of HCC. The evidences from the present study further demonstrate the importance of p53-mediated pathway of apoptosis in HCC, and also point for possible differences in carcinogenesis in cirrhotic versus non-cirrhotic livers

APA, Harvard, Vancouver, ISO, and other styles

35

Silva, Daniela Stochmann [UNESP]. "Detecção de gene TP53 e expressão das proteínas p53, Bcl-2 e p63 no tumor venéreo transmissível canino." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/92195.

Full text

Abstract:

Made available in DSpace on 2014-06-11T19:25:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-10-29Bitstream added on 2014-06-13T20:33:23Z : No. of bitstreams: 1 silva_ds_me_araca.pdf: 824748 bytes, checksum: a5191c74f89f8870aa31a3483beae50a (MD5)
O tumor venéreo transmissível canino (TVTC) é uma neoplasia transmitida entre cães saudáveis pelo contato direto de pele e/ou mucosas lesionadas. Face aos escassos estudos relacionados aos eventos celulares envolvidos nas fases de crescimento do TVTC, o presente estudo teve por objetivo identificar a presença do gene TP53 e o RNAm referente a proteína codificada, além de detectar a expressão das proteínas p53, Bcl-2 e p63 em cortes histológicos de 13 amostras de TVTC. Com relação à evolução da neoplasia, 46% das amostras foram consideradas em fase de progressão e 54% no estágio de regressão. Foram utilizadas as técnicas de hibridização in situ (ISH) e RT-PCR in situ, que demonstrou a presença do DNA homólogo ao TP53 e seu respectivo RNAm em 92,30% das amostras. A expressão das proteínas p53, p63 e Bcl-2 foram detectadas em 50%, 70% e 100% das amostras, respectivamente. A p63 foi expressa de forma evidente nas amostras em regressão, porém a p53 e a Bcl-2 não apresentaram relação com o estágio evolutivo do tumor e provavelmente não podem ser analisados como fatores de prognóstico do TVTC. Observou-se, nesse estudo que, através das técnicas de ISH e RT-PCR in situ foi possível detectar o DNA do TP53 e seus transcritos, porém esse fato não significou a transcrição da p53, devido aos baixos níveis de expressão nas análises quantitativa e qualitativa nas amostras de TVTC
The canine transmissible venereal tumor (CTVT) is transmitted by direct contact of skin or mucosal presenting lesions. In fact, few reports have been found describing the cellular immune response related to the evolution of the tumor. The objective of this study was to identify the TP53 gen and its transcription in CTVT in different stages of evolution, collected from dogs (N=13) examined at veterinary school, UNESP, Aracatuba, SP, Brasil. In addition, it was also evaluated the expression of p53, p63 and Bcl-2 in histological sections by the use of immunohistochemystry assay. The p53, p63 and Bcl-2 were evident in 50, 70 and 100% of analyzed samples. Regarding to tumor evolution, 6 out of 13 were considered in a progressive stage (46%), was list 7 out of 13 were classified in a regressive stage (54%). The use of in situ hybridization and reverse transcriptase polymerase chain reaction in situ (RT-PCR), revealed that TP53 was present in all samples and P63 was more expressed than p53. Take all results together, the real role of those marker are extremely important to understand the biological behavior and to improve therapeutic procedures for CTVT

APA, Harvard, Vancouver, ISO, and other styles

36

Silva, Daniela Stochmann. "Detecção de gene TP53 e expressão das proteínas p53, Bcl-2 e p63 no tumor venéreo transmissível canino /." Araçatuba : [s.n.], 2010. http://hdl.handle.net/11449/92195.

Full text

Abstract:

Resumo: O tumor venéreo transmissível canino (TVTC) é uma neoplasia transmitida entre cães saudáveis pelo contato direto de pele e/ou mucosas lesionadas. Face aos escassos estudos relacionados aos eventos celulares envolvidos nas fases de crescimento do TVTC, o presente estudo teve por objetivo identificar a presença do gene TP53 e o RNAm referente a proteína codificada, além de detectar a expressão das proteínas p53, Bcl-2 e p63 em cortes histológicos de 13 amostras de TVTC. Com relação à evolução da neoplasia, 46% das amostras foram consideradas em fase de progressão e 54% no estágio de regressão. Foram utilizadas as técnicas de hibridização in situ (ISH) e RT-PCR in situ, que demonstrou a presença do DNA homólogo ao TP53 e seu respectivo RNAm em 92,30% das amostras. A expressão das proteínas p53, p63 e Bcl-2 foram detectadas em 50%, 70% e 100% das amostras, respectivamente. A p63 foi expressa de forma evidente nas amostras em regressão, porém a p53 e a Bcl-2 não apresentaram relação com o estágio evolutivo do tumor e provavelmente não podem ser analisados como fatores de prognóstico do TVTC. Observou-se, nesse estudo que, através das técnicas de ISH e RT-PCR in situ foi possível detectar o DNA do TP53 e seus transcritos, porém esse fato não significou a transcrição da p53, devido aos baixos níveis de expressão nas análises quantitativa e qualitativa nas amostras de TVTC
Abstract: The canine transmissible venereal tumor (CTVT) is transmitted by direct contact of skin or mucosal presenting lesions. In fact, few reports have been found describing the cellular immune response related to the evolution of the tumor. The objective of this study was to identify the TP53 gen and its transcription in CTVT in different stages of evolution, collected from dogs (N=13) examined at veterinary school, UNESP, Aracatuba, SP, Brasil. In addition, it was also evaluated the expression of p53, p63 and Bcl-2 in histological sections by the use of immunohistochemystry assay. The p53, p63 and Bcl-2 were evident in 50, 70 and 100% of analyzed samples. Regarding to tumor evolution, 6 out of 13 were considered in a progressive stage (46%), was list 7 out of 13 were classified in a regressive stage (54%). The use of in situ hybridization and reverse transcriptase polymerase chain reaction in situ (RT-PCR), revealed that TP53 was present in all samples and P63 was more expressed than p53. Take all results together, the real role of those marker are extremely important to understand the biological behavior and to improve therapeutic procedures for CTVT
Orientador: Maria Cecília Rui Luvizotto
Coorientador: Tereza Cristina Cardoso
Banca: Alexandre Lima de Andrade
Banca: Paula Rahal
Mestre

APA, Harvard, Vancouver, ISO, and other styles

37

Fraga, Lucas Rosa. "Variantes gênicas na via de sinalização das proteínas P53 e P73 e sua relação com perdas gestacionais recorrentes." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2013. http://hdl.handle.net/10183/72377.

Full text

Abstract:

As Perdas Gestacionais Recorrentes (PGR) são definidas como duas ou mais perdas gestacionais consecutivas antes das 24 semanas de gestação. Essa condição, de etiologia complexa, ocorre em cerca de 5% de todos os casais que tentam ter filhos, podendo ser considerada uma condição reprodutiva que merece ser alvo de investigação, principalmente pelo fato de que, em aproximadamente 50% dos casos, sua etiologia permanece desconhecida. A família de proteínas p53 é composta por fatores de transcrição cujos membros, p53, p63 e p73 compartilham uma estrutura geral e funções primárias no controle do ciclo celular, sendo capazes de induzir parada do ciclo celular e morte celular em respostas a danos no DNA. Na reprodução, atuam: p53, na regulação de diversos genes envolvidos na apoptose e angiogênese, mecanismos fundamentais para uma adequada gestação, além de regular o gene LIF, cujo produto prepara o útero para a implantação do blastocisto; p63, como a maior reguladora do processo que controla a qualidade e sobrevivência da linhagem germinativa feminina através da eliminação por apoptose; e p73, na manutenção da qualidade dos oócitos através do controle do fuso mitótico. Essas proteínas são reguladas, principalmente, por proteínas envolvidas no processo de ubiquitinação, sendo elas: Mdm2, principal reguladora da rota, reduzindo os níveis de p53, p63 e p73; Mdm4, homóloga a Mdm2, atuando da mesma forma sobre a família; e Usp7, que atua apenas sobre Mdm2, Mdm4 e p53, deubiquitinando-as e, assim, estabilizando essa rota. Nesse trabalho foi investigado o efeito das variantes polimórficas nos genes da família p53 e seus principais reguladores, sendo essas c.215G>C - Pro72Arg de TP53 (rs1042522), c.325-4742T>G de TP63 (rs17506395), 4c.-30G>A e 14c.-20C>T de TP73 (rs2273953, rs1801173), c.14+309T>G de MDM2 (rs2279744), c.753+572C>T de MDM4 (rs1563828), c.2719-234G>A de USP7 (rs1529916) e c.1414T>G de LIF (rs929271), como fator de risco para perdas gestacionais recorrentes. Foram avaliadas 153 mulheres com perdas gestacionais recorrentes e 143 mulheres com pelo menos dois filhos vivos e sem histórico de perdas gestacionais ou infertilidade. A distribuição das freqüências alélicas e genotípicas não se mostrou diferente entre os dois grupos, entretanto, análises de interação entre os genótipos de risco de TP53 (Arg/Arg) e MDM2 (TT) e, TP63 (TT) e MDM2 (TT) foram associadas ao aumento do risco para PGR (OR = 2,58; 95% IC: 1,31 – 5,07; p = 0,006; e OR = 2,13; IC: 1,18 – 3,82; p = 0,011, respectivamente). Com base nestas observações e em dados de literatura, sugere-se que a presença concomitante de genótipos Arg/Arg de TP53 e TT de MDM2 levam a um aumento dos níveis de p53, o que propicia indução da apoptose mais eficiente podendo estar correlacionada a uma maior suscetibilidade a PGR. Em relação à interação de MDM2 e TP63, mesmo sem a compreensão do efeito deste polimorfismo sobre a função de p63, sabe-se que o genótipo MDM2 TT resulta em menores níveis da proteína. Como consequência, maiores níveis de p63 nos oócitos, ovário e útero seriam esperados, o que também levaria a maior chance de PGR. Os achados deste trabalho reforçam a hipótese do envolvimento da família p53 no controle da reprodução materna. Através dos mecanismos pró-apoptóticos e de controle de ciclo celular semelhantes, porém independentes, as atividades dessas proteínas na fisiologia da reprodução materna influenciam no desfecho gestacional, incluindo a fisiopatologia das PGR.
Recurrent pregnancy loss (RPL) is defined as two or more consecutives pregnancy losses before 24 weeks of gestation. This condition of complex etiology, occurs in about 5% of all couples trying to conceive and may be considered a reproductive disorder that deserves to be investigated, mainly due the fact that, in approximately 50% of cases, the etiology remains unknown. The p53 family proteins is a family of transcription factors whose members p53, p63 and p73 share a general structure and primary functions in cell cycle control, being able of induce cell cycle arrest and cell death in response to DNA damage. In reproduction, act: p53, in the regulation of several genes involved in apoptosis and angiogenesis, fundamental mechanisms for an appropriate pregnancy, also regulates LIF gene expression, whose product prepares the uterus for implantation of the blastocyst; p63, as the main regulator of process that control the quality and survival of female germ line through elimination by apoptosis; and p73, in maintaining the quality of the oocytes by controlling the mitotic spindle. These proteins are regulated mainly by proteins involved in the ubiquitination process, namely: Mdm2, main regulator of the route, reducing p53, p63 and p73 levels; Mdm4, homologous to Mdm2, acting the similarly on family; and Usp7, which acts only on Mdm2, Mdm4 and p53, deubiquitinating them and thus stabilizing this route. In this study was investigated the effect of polymorphic variants in genes of the p53 family and its main regulators, these being c.215G>C - Pro72Arg of TP53 (rs1042522), c.325-4742T>G of TP63 (rs17506395), 4c.-30G>A e 14c.-20C>T of TP73 (rs2273953, rs1801173), c.14+309T>G of MDM2 (rs2279744), c.753+572C>T of MDM4 (rs1563828), c.2719-234G>A of USP7 (rs1529916) and c.1414T>G of LIF (rs929271), as risk factor to recurrent pregnancy loss. Were evaluated 153 women with recurrent pregnancy loss and 143 women with at least two live births and no history of pregnancy loss or infertility. The distribution of allelic and genotypic frequencies did not differ between the two groups, however, analysis of the interaction between the risk genotypes of TP53 (Arg/Arg) and MDM2 (TT), and TP63 (TT) and MDM2 (TT) were associated to increased risk for PGR (OR = 2.58, 95% CI: 1.31 - 5.07, p = 0.006; and OR = 2.13; OR = 2.13; IC: 1.18 - 3.82; p = 0.011, respectively). Based on these observations and on literature data, suggests that the simultaneous presence of genotypes Arg/Arg of TP53 and TT of MDM2 leads to an increase in p53 levels, which provides more effective induction of apoptosis and can be correlated with an increased susceptibility to RPL. Regarding the interaction of MDM2 and TP63, even without understanding the effect of this polymorphism on the function of p63, it is known that MDM2 TT genotype results in lower levels of the protein. As a consequence, higher levels of p63 in oocytes, ovary and uterus would be expected, which would also lead to a increased risk of RPL. The hypothesis of this study is that the mechanism which p53 and p63 is acting on women with recurrent pregnancy is through an post-implantation event. The findings of this study support the hypothesis of the involvement of p53 family on maternal reproduction control. Through the pro-apoptotic mechanisms and cell cycle control similar nevertheless independents, activities of these proteins in the maternal reproduction physiology influence on the pregnancy outcome, including the pathophysiology of RPL.

APA, Harvard, Vancouver, ISO, and other styles

38

Freitas, Leandro Luiz Lopes de. "Analise imunoistoquimica de proteinas relacionadas ao ciclo celular (p53, Ki-67, bcl-2 e c-erbB-2) na transformação maligna do adenoma plenomorfico de glandula salivar." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/313780.

Full text

Abstract:

Orientador: Albina Messias de Almeida Milani Altemani
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas
Made available in DSpace on 2018-08-06T19:08:01Z (GMT). No. of bitstreams: 1 Freitas_LeandroLuizLopesde_D.pdf: 4064664 bytes, checksum: d04222e584211904229193f280c217a9 (MD5) Previous issue date: 2006
Resumo: O adenoma pleomórfico (AP) é a neoplasia mais freqüente das glândulas salivares e o carcinoma ex-adenoma pleomórfico (CXAP) é a sua forma de transformação maligna mais comum. Os trabalhos da literatura com séries exclusivas de CXAP são poucos e englobam, em sua maioria, carcinomas já em estádios avançados. Raros são os estudos realizados exclusivamente com tumores que apresentam os dois componentes (benigno e maligno) e em fases iniciais de malignização. Alterações nos genes p53 e c-erbB-2 parecem ser as principais vias envolvidas nesta transformação. Estas proteínas, além do marcador de proliferação celular Ki-67, podem ser importantes critérios no diagnóstico do CXAP, especialmente em sua fase precoce. O objetivo deste trabalho foi avaliar retrospectivamente a expressão imunoistoquímica de marcadores celulares (p53, c-erbB-2, Ki-67 e bcl-2, uma proteína antiapoptótica) em CXAP em diferentes fases de malignização (4 intracapsulares, 4 minimamente invasivos e 7 francamente invasivos), nas áreas benignas e malignas e em AP que não sofreram malignização (17 casos - grupo controle). A parótida foi a glândula mais acometida em ambos os grupos (CXAP 53%, grupo controle 88%), envolvendo mais mulheres que homens. A idade média dos pacientes com CXAP em qualquer fase evolutiva (63,3 anos) foi maior que no grupo controle (35,6 anos). A proteína p53 foi mais expressa nas áreas malignas (em média 35,71% nos CXAP precoces e 8,11% nos CXAP francamente invasivos, versus 12,76% e 4,58% nas áreas benignas, respectivamente) e principalmente em células luminais, enquanto os menores valores foram encontrados no grupo controle (1,71%). Fato semelhante ocorreu com o índice mitótico e a expressão de Ki-67. A expressão de c-erbB-2 foi observada quase que exclusivamente em células malignas com diferenciação luminal. A proteína bcl-2 teve positividade fraca e focal. Concluímos que as proteínas p53 e c-erbB-2 parecem estar envolvidas na transformação maligna do AP, já em fases precoces, sendo critérios mais objetivos do que a simples avaliação morfológica para o diagnóstico dos CXAP intracapsulares
Abstract: Pleomorphic adenoma (PA) is the commonest salivary gland tumor, and carcinoma ex pleomorphic adenoma (CXPA) is its most frequent malignant counterpart. There are few studies centering on CXPA only and most have been performed in frankly invasive carcinomas. Series of CXPA containing both morphological components (adenoma and carcinoma) at an early stage of carcinomatous transformation are extremely rare. p53 and c-erbB-2 appear to be the most important genes involved in this malignant change. These proteins, and the proliferative index marker Ki-67, could be valuable criteria for diagnosis of CXPA, specially at an early stage. The aim of this study was to assess retrospectively the expression of cell markers (p53, c-erbB-2, Ki-67 and bcl-2, an antiapoptotic protein) in CXPA in different phases of malignant progression (4 intracapsular, 4 minimally invasive and 7 frankly invasive), in benign and malignant areas and in PA without malignant transformation (17 cases - control group). The parotid was the most frequently involved gland in both groups (CXPA: 53%, control group: 88%), and women were more affected than men. The average age in the CXPA group (63.3 years) at any stage was higher than in the control group (35.6 years). p53 expression was highest in malignant areas (mean 35.71% in early CXPA and 8.11% in frankly invasive CXPA, versus 12.76% and 4.58% in benign areas, respectively) and mainly in luminal cells, while the lowest values (1.71%) occurred in the control group. Similar findings were obtained with the mitotic index and Ki-67 expression. c-erbB-2 positivity was observed almost exclusively in malignant cells of the luminal type. bcl-2 expression was weak and focal. In conclusion, both p53 and c-erbB-2 proteins appear to be involved in malignization of PA since an early stage, thus providing criteria more objetive than simple morphological evaluation for diagnosis of intracapsular CXPA
Doutorado
Anatomia Patologica
Doutor em Ciências Médicas

APA, Harvard, Vancouver, ISO, and other styles

39

Wikarská, Monika. "Příprava a exprese izoforem proteinu p53 pomocí GATEWAY expresního systému." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2019. http://www.nusl.cz/ntk/nusl-401891.

Full text

Abstract:

The TP53 gene can express protein p53 and 11 another isoform proteins N- and/or C-terminally truncated by using two promoters and alternative splicing. The p53 isoforms are found in both healthy and tumorous tissues, and are intensively studied in relation to cancer diagnosis, prognosis and treatment. In this work, the p53 isoforms were subcloned into expression vectors by LR reaction adapted from Gateway cloning system. The expression vectors were designed for protein production by bacteria E. coli strain BL-21. The constructs containing p53 isoforms were encoded together with two fusion proteins, glutathione-S-transferase and polyhistidine tag under the control of the same promotor for the affinity chromatography protein isolation. All the clones underwent Sanger sequencing for verification after homologous recombination. Sequencing confirmed the accuracy of the subcloned isoforms p53, 133p53, 160p53, p53 and 160p53 into an expression vector pDEST15-N6xHis-GST-GW-DEST. Protein 160p53 was expressed in BL-21 and isolated using both HIS and GST tag interacion. Isolation using HIS tag yielded in a higher protein concentration then the isolation mediated by the interaction of the glutathione-S-transferase.

APA, Harvard, Vancouver, ISO, and other styles

40

Silins, Ilona. "Regulation of p53 and susceptibility to cell death in chemically-induced preneoplastic hepatocytes /." Stockholm, 2003. http://diss.kib.ki.se/2003/91-7349-705-3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Saliba, David George. "On the ubiquitination and protein-protein interactions of p53." Thesis, University of Edinburgh, 2007. http://hdl.handle.net/1842/11350.

Full text

Abstract:

In this study p53^F270A, p53^R175H, and wild-type (wt) p53 were used as a panel to dissect how oligomeric protein conformation affects p53 ubiquitination and binding of other proteins to p53. p53^F270A is hyperubiquitinated in cells as determined by p53-immunopreciptation and immunoblotting with an anti-ubiquitin antibody. Using a mass-spectrometric approach, eukaryotic elongation factor 1a (eefla) was identified as binding specifically to hyperubiquitinated p53^F270A. In this study, using a one-strep tagged approach, the interactome of p53 was extended by defining stable cellular binding proteins to wild-type and mutant p53. The system faithfully recapitulates the enhanced ubiquitination pattern of the unfolded oncogenic forms of p53. Further, mutually exclusive binding partners were identified for wt and mutant p53: the wild-type protein interacted predominantly with MDM2; whilst the mutant interacted selectively with Heat shock protein 70 (Hsp70) and the TCP-1 beta chaperonin. Upon analyzing the effects of stresses on the p53-interactomes, we identified a Nutlin and 17-(allylamino)-17-demethoxy-geldanamycin (17-AAG)-induced binding to a novel spiced form of HSP90 lacking the N-terminus (HSP90ΔN). Ionizing radiation did not induce the formation of a p53: HSP90ΔN complex. By contrast, the oncogenic and hyperubiquitinated mutant p53 was constitutively bound to HSP90ΔN. These data expand on the Interactome of p53 and identify eefla and HSP90ΔN as novel components of signalling pathways that control p53 homeostasis.

APA, Harvard, Vancouver, ISO, and other styles

42

Yuan, Zhigang. "Functional characterization of roles of histone deacetylases in the regulation of DNA damage response." [Tampa, Fla.] : University of South Florida, 2007. http://purl.fcla.edu/usf/dc/et/SFE0002175.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Rosa, Jack. "Perturbation and Modulation of Microtubule Cytoskeletal Elements in Response to the Potentially Oncogenic Molecules, Survivin and P53, and Cytokinesis: A Dissertation." eScholarship@UMMS, 2006. https://escholarship.umassmed.edu/gsbs_diss/280.

Full text

Abstract:

A complex network of protein filaments collectively known as the cytoskeleton carries out several crucial cellular processes. These functions include, but are not limited to, motility, cell shape, mitosis and organelle trafficking. The cytoskeleton is also highly responsive, allowing the cell to alter its shape in response to its immediate needs and environment. One of the major components of the cytoskeleton is the microtubule network. To refer to the array of micro tubules in the cell as a skeleton is a misnomer. Microtubules, by virtue of their structure and nature, are highly dynamic, continuously growing and shrinking. They also bind a variety of accessory molecules that aid in regulating and directing their dynamic activity. In this way they provide a structural basis for integral cell functions that require rapid assembly and disassembly. In some cases, perturbations of the microtubule network results in structural anomalies that lead to undesirable outcomes for the cell, namely chromosomal missegregation events and instability. The accumulation of these events may induce aneuploidy, which has been a fundamental component of tumorigenesis. This dissertation examines the role of the microtubule cytoskeleton within three distinct contexts. The first chapter investigates the association of the anti-apoptotic protein survivin with the microtubule network and its potential impact upon the cell from interphase to cytokinesis. The second chapter of this dissertation explores a little-studied, microtubule-dense organelle, referred to as the midbody, and the highly orchestrated events that take place within it during cytokinesis. The third and final chapter describes a unique experimental condition that may further our understanding of the interaction between the tumor suppressor p53 and the centrosome in cell cycle regulation and tumorigenesis.

APA, Harvard, Vancouver, ISO, and other styles

44

Shouse, Geoffrey P. "Characterization of the functional interaction between two tumor suppressors p53 and B56Gamma-PP2A /." Diss., UC access only, 2009. http://proquest.umi.com/pqdweb?index=31&did=1790085501&SrchMode=1&sid=2&Fmt=7&retrieveGroup=0&VType=PQD&VInst=PROD&RQT=309&VName=PQD&TS=1270138690&clientId=48051.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Heberling, Matthew Michael. "Improving stability of tumor suppressor protein, p53." Connect to resource, 2007. http://hdl.handle.net/1811/28445.

Full text

Abstract:

Thesis (Honors)--Ohio State University, 2007.
Title from first page of PDF file. Document formatted into pages: contains 25 p.; also includes graphics. Includes bibliographical references (p. 23-25). Available online via Ohio State University's Knowledge Bank.

APA, Harvard, Vancouver, ISO, and other styles

46

CORNELIS, LERAT FRANCOISE. "Analyse de l'expression de la proteine p53 dans les tumeurs gliales du systeme nerveux central." Reims, 1993. http://www.theses.fr/1993REIMM056.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Cuella-Martin, Raquel. "Molecular regulation of p53-dependent tumour suppressor responses by the p53 binding protein 1." Thesis, University of Oxford, 2018. http://ora.ox.ac.uk/objects/uuid:7b2e64f3-bda4-4c3c-aeaf-d27393b7bc07.

Full text

Abstract:

The tumour suppressor p53 binding protein 1 (53BP1), a fundamental node in DNA double strand break (DSB) repair, was identified as a p53-interacting protein over two decades ago. However, its contribution to p53-dependent responses has remained largely enigmatic. Here, using a combination of detailed structure-function approaches and in vivo analyses I aim to unravel this aspect of 53BP1 functionality. I showed 53BP1 to enhance genome-wide p53-dependent transactivation events in response to multiple stress stimuli. Oligomerised 53BP1 relies on the tandem BRCT domain, dispensable for 53BP1-driven DSB repair, to bridge dual interactions with p53 and the ubiquitin specific protease 28 (USP28). These interactions are both essential for 53BP1-dependent modulation of p53 functionality. Indeed, the cooperation between 53BP1 and USP28 is required for proficient p53-dependent G1/S checkpoint and senescence responses. Mechanistically, the action of the USP28-53BP1 complex involves differential ubiquitination events that ultimately stimulate p53's ability to bind the responsive elements (RE) in its target genes. Furthermore, I demonstrated 53BP1-driven p53 modulation to function independently of 53BP1's well-described DSB repair roles, and be separable by specific point mutations within 53BP1 architecture. Translation to in vivo mouse models revealed 53BP1-driven DSB repair to be responsible for 53BP1's role in the physiology of the immune system, while functional 53BP1-p53 connections result in effective quality control of chromosomal dosage upon defective mitotic division. Collectively, my findings define 53BP1 as an integral node in genome stability control, driving efficient DSB repair and mitotic surveillance mechanisms.

APA, Harvard, Vancouver, ISO, and other styles

48

Fitzgerald, Ross Patrick. "Small molecule inhibitors of the p53-MDM2 protein-protein interaction." Thesis, University of Nottingham, 2011. http://eprints.nottingham.ac.uk/13136/.

Full text

Abstract:

In Chapter 2, bis- and tris- arylsulfonamides, were investigated as possible inhibitors of the p53-MDM2 protein-protein interaction (PPI). The lead compound, 19, inhibited the PPI, in a fluorescence polarisation (FP) based competitive binding assay with ICso 26.4 pM and the most potent analogue, 66, with ICso 3 μM. The active compounds in this series, possess a 5-chloro-4-nitro-2-sulfonamoyl substituted thiophene ring that is very susceptible to SNAr reactions at the 5-position. Analogues of 19 and 66 were prepared to investigate the SAR of these inhibitors. No improvements in activity or structural activity relationship (SAR) consistent with MDM2 binding were observed and no active analogues without the reactive functionality were found. These compound are no longer being investigated. Chapter 3 describes a 3-D shape-based virtual screening campaign to find new lead compounds. Using queries based on the established Nutlin, benzodiazepine and spiro-oxindole inhibitors, the ZINC database was screened using the program ROCS to find compounds that have good shape similarity (measured by 3D Tanimoto) and similar functional group overlap to the query molecules. 155 compounds were purchased and tested 16 of which inhibited the MDM2-p53 PPI in the FP assay at IC50 ranging between 48.22 and 140.42 1tM. Three analogues, 156,168 and 180, induce low levels of p53 induction in cells using a Luciferese based reporter gene assay with most the potent compound, 180, showed 5.75 fold induction at 8.89 μM. A number of the hit compounds warrant further investigation. Chapter 4 describes the investigation 1.5-benzodiazepiene-2-ones and 1,3-dihydrobenzimidazolin-2-ones as novel scaffolds on which to base potential p53 inhibitors. A small series of analogues of each class were prepared and their ability to disrupt the MDM2-p53 PPI determined using an FP assay. None of the 1.5-benzodiazepiene-2-ones showed any inhibition of the PPI at concentrations up to 500 μM. Some of the 1,3 dihydrobenzimidazolin-2-one based compounds showed low levels of inhibition with the most potent analogue, 214 having IC5o 196.18 PM. These inhibitors showed some SAR based on the size of substituents and the presence of a 6-chloro substituent that has been shown to considerably enhance the activity in other classes of inhibitor. Compounds of this type warrant further investigation using a more diverse compound library.

APA, Harvard, Vancouver, ISO, and other styles

49

Serra, Kátia Piton 1979. "Subtipos clínico-patológicos de carcinoma de mama e sua relação com a expressão da COX2 e da p53 = Clinico-pathological subtypes of breast cancer related to COX2 and p53." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/313100.

Full text

Abstract:

Orientadores: Sophie Fraçoise Mauricette Derchain, Luís Otávio Zanatta Sarian
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas
Made available in DSpace on 2018-08-26T00:11:32Z (GMT). No. of bitstreams: 1 Serra_KatiaPiton_D.pdf: 3794654 bytes, checksum: ce5565714883e2e12d99e6f9ed0ca141 (MD5) Previous issue date: 2014
Resumo: Introdução: Na última década, doferentes subtipos moleculares de cancer de mama foram propostos. A classificação clinic-patológicas dos subtipos vem comprovando ser estratégica para predizer sobrevida e resposta ao tratamento. Modificação recente da classificação considera a avaliação semiquantitativa da expressão dos RP no curso clínico e resposta ao tratamento. Embora exista associação apreciável com o prognóstico e indicação de terapia citotóxica e endócrina, os subtipos parecem falhar em explicar completamente o comçortamento da doença e a resposta ao tratamento. Moléculas como as da família das cicloxigenases (COX), composta por três entidades (COX 1, 2 e 3) vem demonstrando associação com a carcinogênese mamária, e a análise da expressão da p53 nos tumores de mama pode também oferecer informações adicionais para determinação do prognóstico. Objetivos: Foi avaliada a associação entre os subtipos clinic-patológicos do cancer de mama com o prognóstico e fatores preditivos em uma relativamente grande casuística de pacientes Brasileiras com câncer de mama, que foram acompanhadas por cerca de quatro anos. Foram discutidas as vantagens e possíveis ressalvas relacionadas à nova classificação. Também foi mensurada a expressão da COX2 e da p53 em relação aos subtipos clínico-patológicos e avaliada se a expressão destas molécular poderia explicar a variabilidade no prognóstico ainda encontrada entre os subtipos clínico-patológicos do câncer de mama. Metodologia: Um total de 183 amostras de cancer de mama foram obtidas de mulheres tratadas no Hospital da Mulher da Universidade Estadual de Campinas, Campinas, Brasil, entre Junho de 2008 e Janeiro de 2011. Tissue microarrays (TMA) foram construídos dos blocos originais de parafina para realização de imunoistoquímica (IQ) e hibridização fluorescente in situ (FISH). IQ foi realizada para detecção da expressão de RE, RP, ki67, COX2 e p53; o status do HER2 foi avaliado por FISH nas 183 amostras. Os tumores foram classificados em cinco categorias de acordo com a definição correspondente clinic-patológica dos dos subtipos intrínsecos do câncer de mama, definida durante a 13th St Gallen International Breast Cancer Conference (2013). As características clínicas e patológicas das pacientes e seus tumors e a sobrevida foi avaliada em relação aos subtipos clínico-patológicos, a COX2 e a p53. O tempo médio de seguimento foi 2,94 anos (90% faixa central = 0,93 a 4,1 anos). Resultados: Aproximadamente 75% dos tumors foram classificados como luminais-like. OS HER2 positivos (não luminais) somaram 9,3% dos casos e os Triplos-negativos 13,1%. Os Luminais B-like e HER2 positivos (não luminais) foram associados a alto grau histológico quando comparados aos Luminais A-like (p<0,01). Os Luminais A-like associaram-se significativamente com melhor sobrevida global e livre de doença quando comparados aos HER2 positivos (não luminais) e Triplos-negativos. Não houve tendência à expressão de COX2 relacionada aos subtipos de Luminal A-like a Triplo-negativo. Em contraste, a p53 se expressou em cerca de 67% dos tumores Luminais A-like, 50% dos Luminais B-like HER2 positivos, 60,9% dos Luminais B-like HER2 negativos, 82% dos HER2 positivos (não luminais) e 87% dos Triplos-negativos (p para tendências = 0.06). Houve uma significativa expressão de COX2 nos tumors (66,9%) quando a p53 eram também positive, comparada àqueles tumors que não expressavam p53 (em cujo caso apenas 18,0% dos tumores foram positivos para COX2; p<0,001). Nem a COX2, nem a p53 se relacionaram à sobrevida das pacientes. Conclusões: O critério mais estrito para definer os tumors Luminais A-like aumentou a acurácia da classificação para selecionar tumors que partilhem um bom prognóstico e respondam a terapia endócrina. Parece haver uma associação positive entre a expressão da COX2 e da p53. Por outro lado, nem a expressão da COX2 nem a da p53 se associaram aos subtipos clínico-patológicos, características clínicas e do tumor e ao prognóstico. Parece ser muito cedo para eleger a detecção de COX2 usando IQ como ferramenta de prognóstico ou preditiva, mas evidências incipientes apontam para um possível papel para o marcador
Abstract: Background: In the last decade, different molecular subtypes of breast cancer have been proposed. The clinico-pathological surrogate subtypes of breast cancer classification has been proven as straightforward strategy to predict patient survival and response to treatment. Recent modifications to the classification considered the semi quantitative evaluation of the expression of PR in the clinical course and response to treatment. Although displaying appreciable association with disease prognosis and the prognostic value of cytotoxic and endocrine therapeutic modalities, the subtypes seem to fail at completely explaining disease behavior and response to treatment. Molecules such as those of the cyclocooxigenase (COX) family, currently composed of three entities (COX 1, 2 and 3) have been shown to be associated with breast carcinogenesis, and the analysis of p53 expression in breast tumors may also offer some additional prognostic clues. Objectives: We tested the association of the current clinico-pathological surrogate subtypes of breast cancer with the main prognostic and predictive factors in a relatively large dataset of breast cancer Brazilian patients, which were followed up for almost four years. We discuss the advantages and possible caveats related to this new classification. Our study also assessed COX2 and p53 expression in these clinico-pathological subtypes, and evaluated whether the expression of these molecules could help further explain the variability in prognosis still found within the surrogate molecular groups of breast cancer. Methods: A total of 183 breast cancer samples were obtained from women treated at the Women's Hospital of Campinas State University, Campinas, Brazil, between June 2008 and January 2011. Tissue microarrays (TMA) were constructed from the original paraffin blocks for immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) analyses. Immunohistochemistry was performed to detect the expression of ER, PR, ki67, COX2, and p53; the HER2 status of the 183 specimens was assessed using FISH. Tumors were subtyped into five distinct categories according to the Clinico-Pathological surrogate definitions of intrinsic subtypes of breast cancer defined during the 13th St Gallen International Breast Cancer Conference (2013). Clinical and pathological features of patients and their tumors, and patients¿ survival were assessed in relation to the surrogate subtypes, COX2 and p53. Mean follow-up time was 2.94 years (90% central range = 0.93 to 4.1 years). Results: Approximately 75% of the tumors were classified as luminal-type-like. HER2 positive (non-luminal) tumors accounted for 9.3% of the cases and Triple-negative tumors for the remainder 13.1%. Luminal B-like and HER2 positive (non-luminal) tumors were associated with higher histological grades when compared to Luminal A-like tumors (p<0.01). Luminal A-like tumors were significantly associated with better disease free and overall survival when compared to HER2 positive (non-luminal) and Triple-negative tumors. There was no trend in COX2 overexpression from Luminal A to Triple-negative subtypes. By contrast, p53 was expressed in roughly 67% of the Luminal A-like tumors, 50% of the Luminal B-like HER2 positive tumors, 60.9% of the Luminal B-like HER2 negative, approximately 82% of the HER2 positive (non-luminal) and 87% of the Triple-negative tumors (p for trends = 0.06). There was a significantly higher proportion of COX2 positive tumors (66.9%) when p53 was also positive compared to when the tumor was negative for p53 (in which case only 18.0% of the tumors were positive for COX2; p<0.001). Neither COX2 nor p53 were found to be associated with patients¿ survival. Conclusions: The more strict criteria to define Luminal A-like tumors increased the accuracy of the classification by selecting tumors that share a good prognosis and response to endocrine therapy.There seems to be a positive association between the expressions of COX2 and p53. On the other hand, neither the expression of COX nor that of p53 was associated with clinic-pathological subtypes, tumor features and prognosis. It seems to be too early to elect the detection of COX2 using IHC as prognostic or predictive tool, but incipient evidence points towards a possible role for the marker
Doutorado
Oncologia Ginecológica e Mamária
Doutora em Ciências da Saúde

APA, Harvard, Vancouver, ISO, and other styles

50

Dubois, Nicole. "Untersuchungen zur Expression p53-regulierter Gene nach Reduktion der zellulären Level des INHAT Repressors NIR mittels RNA- Interferenztechnologie." Giessen : VVB Laufersweiler, 2007. http://d-nb.info/988006707/04.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic 'ProteÃna p53'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles