Dissertationen zum Thema „Bcl-2 Receptors“

Orientador: Lúcia Helena Simões da Costa Paiva
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas
Made available in DSpace on 2018-11-07T13:42:39Z (GMT). No. of bitstreams: 1 Pinheiro_Anderson_M.pdf: 3122120 bytes, checksum: dced5efa50ee11a7d5554366020908bb (MD5) Previous issue date: 2012
Resumo: Introdução: A prevalência de obesidade tem aumentado em todo o mundo e hoje já representa um problema de saúde pública. Na população feminina, seu aumento ocorre principalmente nos anos próximos da transição para menopausa. O aumento de peso representa um risco para diversas comorbidades, dentre elas um importante fator de risco para patologia endometrial. A etiologia e a patogênese dos pólipos não estão completamente esclarecidas. Estuda-se se o desenvolvimento dos pólipos endometriais está diretamente relacionado à presença de receptores hormonais, além de estar relacionado a mecanismos envolvidos à proliferação e à apoptose celular. Objetivos: Avaliar a imunoexpressão dos receptores de estrógeno (RE), progesterona (RP), Cox-2, Ki67 e Bcl-2 em pólipos endometriais benignos na pré e pós-menopausa e associação com a obesidade. Materiais e métodos: Dentre 1050 mulheres submetidas à histeroscopia cirúrgica no Hospital da Mulher Prof. Dr. Aristodemo Pinotti - CAISM/UNICAMP, de janeiro de 1998 a dezembro de 2008, 800 foram casos de polipectomia endometrial confirmados com exame anatomopatológico. Deste total, foram excluídas as usuárias de Tamoxifeno, as que faziam uso de terapia hormonal e os casos de pólipos malignos ou pré-malignos. Obteve-se uma amostra de 515 pólipos endometriais benignos em mulheres na pré e pós-menopausa. Foram avaliadas as expressões de RE, RP, Bcl-2, Ki67 e Cox-2, através de imuno-histoquímica, segundo a porcentagem de células coradas, intensidade da coloração e escore final. Os escores finais de RE, RP, Bcl-2, Cox-2 variam de 0 a 8 e o de Ki67 de 0 a 3. A mediana dos escores finais de RE, RP, Bcl-2, Cox-2 e Ki67 no epitélio glandular e no estroma dos pólipos foi comparada entre mulheres obesas e não obesas na pré e pós-menopausa, utilizando os testes qui-quadrado, exato de Fisher ou não paramétrico de Mann-Whitney. Resultados: A mediana do escore final de receptores hormonais mostrou maior expressão de RP no estroma e no epitélio glandular das mulheres obesas na pós-menopausa, sem diferença em relação à expressão dos RE. Em mulheres na pré-menopausa não houve diferença na expressão de RE e RP entre obesas e não obesas. Nos pólipos endometriais de mulheres pós-menopausadas houve maior expressão de Cox-2 e Bcl-2 no epitélio glandular das mulheres obesas do que em relação às mulheres não obesas. Não houve diferenças em relação ao estroma endometrial. Na pré-menopausa, houve maior expressão de Bcl-2 apenas no epitélio glandular das mulheres obesas. Não houve diferenças na expressão de Ki67 entre obesas e não obesas tanto na pós-menopausa quanto na pré-menopausa. Conclusões: Os pólipos de mulheres obesas apresentam, na pós-menopausa, maior expressão de RP glandular e estromal, Cox-2 glandular e Bcl-2 glandular, sem diferenças na expressão de Ki67. Estes dados sugerem que sua etiopatogênese dos pólipos em obesas parece estar mais relacionada aos receptores de progesterona, à inibição da apoptose e aos mecanismos relacionados à inflamação celular
Abstract: Introduction: The prevalence of obesity has increased worldwide and represents a public health problem nowadays. The female population, considerably presents its increase in the coming years of the transition to menopause. Weight gaining represents a risk for various comorbidities, but among them all, it is an important risk factor for the endometrial pathology. The polyps etiology and pathogenesis have not been completely clarified so far. It has been studied whether the endometrial polyps development is directly related to the presence of hormone receptors, besides being associated with mechanisms involved in the proliferation and cellular apoptosis.Objectives: To evaluate the immunoexpression of estrogen and progesterone receptors, Ki67, Bcl-2 and Cox-2 in benign endometrial polyps in pre and postmenopausal women and their association with obesity. Methods: It was observed that among 1050 women who underwent hysteroscopic surgery at the "Prof. Dr. José Aristodemo Pinotti" Women's Hospital-CAISM-UNICAMP from January 1998 to December 2008, 800 were confirmed with endometrial polyp anatomopathological diagnosis. Of this total amount, it was excluded tamoxifen users, those who used hormone therapy and cases of malignant or pre-malignant polyps. It was obtained a sample of 515 benign endometrial polyps in women before and after menopause. It was also assessed the expression of ER, PR, Bcl-2, COX-2 and Ki67 through immunohistochemistry according to stained cells percentage, staining intensity, and the final score. The ER, PR, Bcl-2, Cox-2 final score ranges from 0 to 8 and the Ki67 from 0 to 3). The ER, PR, Bcl-2, Cox-2 and Ki67 median final scores in the glandular epithelium and stroma of the polyps were compared among obese and nonobese women, in pre and postmenopausal condition, using the Chi-square Fisher's exact test or nonparametric Mann-Whitney test. Results: The hormonal receptors median final score has showed an increased expression of progesterone receptors in the stroma and glandular epithelium of postmenopausal obese women but there was no difference in expression of ER estrogen receptors. In premenopausal women, there was no difference in expression of ER and PR among obese and nonobese women. The endometrial polyps in postmenopausal women have showed a higher expression of Cox-2 and Bcl-2 in glandular epithelium in obese women rather than in nonobese women. There were no differences in the endometrial stroma. In premenopausal women, there was a higher expression of Bcl-2 only in the obese women glandular epithelium. There were no differences in Ki67 expression among obese and nonobese both postmenopausal and premenopausal women. Conclusions: Obese women polyps, in postmenopausal condition, have increased expression of glandular and stromal PR, Cox-2 and Bcl-2 glandular. However, there are no differences in the Ki67 expression . These data suggest that its etiopathogenesis in obese women polyps, seem to be related to progesterone receptors, apoptosis inhibition and also to mechanisms associated with cellular inflammation
Mestrado
Fisiopatologia Ginecológica
Mestre em Ciências da Saúde

L'apoptose, ou « mort cellulaire programmée », joue un rôle clé dans de nombreux processus biologiques. Les protéines de la famille Bcl-2, dont l'expression est souvent altérée dans les cellules tumorales, sont les principaux régulateurs de l'apoptose. Parmi cette famille, la fonction exacte du répresseur apoptotique Nrh, aussi appelé BCL2L10 ou Bcl-B, reste à ce jour mal comprise. Bien que son expression ne soit pas détectable dans la plupart des tissus sains, on retrouve des niveaux élevés de Nrh corrélés à un mauvais pronostique dans les cancers du sein et de la prostate. Nous avons mis au jour un nouveau mécanisme selon lequel Nrz, l'orthologue de Nrh chez le poisson zèbre, interagit avec le domaine de liaison du ligand IP3 du canal calcique IP3R1. Il s'est avéré que la régulation négative des flux calciques par Nrz est critique lors du développement embryonnaire du poisson zèbre. Grâce à ces nouvelles données, nous avons cherché à comprendre la fonction de Nrh chez l'Homme, dans un contexte pathologique. Nous avons montré que Nrh interagit via son domaine BH4 avec le domaine de liaison du ligand du récepteur IP3R1 humain pour réguler l'homéostasie calcique et la mort cellulaire. Cette interaction définit Nrh comme la seule protéine de la famille Bcl-2 à réguler négativement la mort cellulaire exclusivement au niveau du réticulum endoplasmique. Pour aller plus loin, nous avons montré que la dissociation du complexe Nrh/IP3Rs sensibilise des cellules tumorales mammaires à l'action d'agents chimiothérapeutiques. Pour finir, nos résultats apportent une explication moléculaire sur la contribution de Nrh dans la résistance aux thérapies anti-tumorales
Apoptosis, also called “Programmed Cell Death”, plays a key role in many biological processes and pathologies. The B-cell lymphoma 2 (Bcl-2) proteins, whose expression is often altered in tumor cells, are the main regulators of apoptosis.Among this family, the actual physiological function of the human apoptosis inhibitor Nrh, also referred to as BCL2L10 or Bcl-B, remains elusive. Although in most healthy tissues the Nrh protein is nearly undetectable, clinical studies have shown that Nrh expression is correlated with poor prognosis in breast and prostate carcinomas. We have shed light on a novel mechanism by which Nrz, the zebrafish ortholog of Nrh, was found to interact with the Ligand Binding Domain (LBD) of the Inositol-1,4,5-triphosphate receptor (IP3R) type-I Ca2+ channel. Indeed, the regulation of IP3Rs-mediated Ca2+ signaling by Nrz was shown to be critical during zebrafish embryogenesis. We used the knowledge gained with the zebrafish model to investigate Nrh function in cancer. We showed that Nrh interacts with the LBD of IP3Rs via its BH4 (Bcl-2 Homology 4) domain, which is critical to regulate intracellular Ca2+ trafficking and cell death. Actually, this interaction seems to be unique among the Bcl-2 family, and sets Nrh as the only Bcl-2 homolog to negatively regulate apoptosis by acting exclusively at the Endoplasmic Reticulum. Furthermore, we showed that disruption of the Nrh/IP3Rs complex primes Nrh-dependent cells to apoptotic cell death and enhances chemotherapy efficiency in breast cancer cell lines.Lastly our results bring a new insight to the role of Nrh regarding chemotherapy resistance

Les cellules invariantes « natural killer » T (iNKT) constituent une population particulière de LT non conventionnelle qui exprime un récepteur TCRαβ semi-invariant composé de la chaine Vα14-Jα18 associée aux chaines Vβ8, -7 ou -2 chez la souris et dont le développement a lieu dans le thymus. Ainsi, les cellules iNKT sont capables de reconnaitre via leur TCR des antigènes de type glycolipidique présentés par une molécule de classe I non polymorphique : le CD1d. Ces cellules sont connues pour être impliquées dans diverses réponses immunes grâce à leur capacité à produire rapidement des cytokines immunorégulatrices. De la même façon que les LTc SP CD4+, il existe trois phénotypes de cellules iNKT : Th1, -2 et -17 permettant de distinguer trois sous-populations de cellules iNKT. La sous-population iNKT1 dite iNKT conventionnelle exprime des récepteurs appartenant au lignage NK. Cette sous-population est localisée préférentiellement dans le foie, le thymus et la rate et produit majoritairement de l’IFN-. La sous-population iNKT2, qui reste jusqu’à aujourd’hui insuffisamment décrite, se localise préférentiellement dans les poumons et produit majoritairement de l’IL-4 et de l’IL-13. La sous-population iNKT17 a été caractérisée et mise en évidence au sein de notre laboratoire comme une sous-population de cellules iNKT exprimant le facteur de transcription RORt et capable de sécréter de l’IL-17 en réponse à l’IL-1 et l’IL-23 et se localisant principalement dans les ganglions périphériques et la peau. A ce jour, seul le développement des cellules iNKT conventionnelles est bien connu tandis que celui des cellules iNKT17 demeurent ignorés. Ainsi, ayant remarqué une faible proportion des cellules iNKT17 dans le thymus de la souris C57BL/6 comparées aux autres sous-populations de cellules iNKT, nous nous sommes intéressés dans un premier temps à expliquer les causes de cette faible distribution de cette sous-population, ainsi qu’à définir la séquence d’acquisition de ses marqueurs lors de son développement thymique et de sa migration en périphérie. Les résultats montrent que ces cellules n’ont aucun défaut de prolifération, ni de réponse aux cytokines de l’homéostasie permettant d’expliquer leur plus faible nombre. En revanche, nous avons constaté une absence d’accumulation thymique de ces cellules qui ont la capacité de migrer en périphérie, accompagnée d’une sensibilité plus accrue à la mort par apoptose et une diminution de l’expression des facteurs de survie comme le Bcl-2 pouvant ainsi expliquer leur nombre réduit. Les analyses de leur développement aux stades précoces ont montré un biais préétabli de leur faible nombre observable dès le stade CD44-. L’étude de leur ontogénique a permis de montrer une cinétique d’acquisition séquentielle des marqueurs CCR6 et CD138 permettant d’établir pour la première fois un modèle de maturation thymique de cette sous-population iNKT17 qui était encore inconnue. Ainsi, au stade précoce HSAhigh, les cellules iNKT RORt+ observé correspondent à des précurseurs communs des cellules iNKT et non pas à des précurseurs des cellules iNKT17 montrant que la différenciation de ces cellules ne se fait pas au stade de sélection positive et que leur faible nombre dépend des signaux que ces cellules reçoivent lors de leur engagement vers le lignage “Th17 like“
Invariant natural killer cells T (iNKT) constitute a particular population of unconventional LT which expresses a semi-invariant TCRαβ receptor composed of the Vα14-Jα18 chain associated with the Vβ8, -7 or -2 chains in mice and which develops in the thymus. Thus, iNKT cells are able to recognize glycolipid antigens via their TCR presented by a non-polymorphic class I molecule: CD1d. These cells are known to be involved in various immune responses because of their ability to rapidly produce cytokines. However, like conventional SP T CD4+ lymphocytes, iNKT cells can differentiate into three phenotypes: Th1, -2 and -17. The iNKT1 subset also named conventional iNKT cells expresses receptors belonging to the NK lineage, is mainly located in the liver, thymus and spleen and produces mainly IFN-. The iNKT2 subset which until now remains insufficiently described, is localized preferentially in the lungs and produces mainly IL-4 and IL-13. The iNKT17 subset has been characterized in our laboratory as a subset of iNKT cells expressing the RORt transcription factor and capable of secreting IL-17 in response to IL-1 and IL-23 and located mainly in the peripheral lymph nodes and the skin. To date, only the development of conventional iNKT cells is well known while that of iNKT17 cells remains unknown. Thus, having noticed the low distribution of the iNKT17 cells present in the thymus of the C57BL/6 mouse compared to other iNKT cell subset, we were initially interested in explaining the causes of this poor distribution of this subset, as well as to define the acquisition sequence of its markers during its thymic development and peripheral migration. The results show that these cells have no defect of proliferation or response to cytokines of homeostasis that can explain their lower number in the thymus. In contrast, we found a lack of thymic accumulation of these cells that have the ability to migrate peripherally, accompanied by increased sensitivity to death by apoptosis and decreased expression of survival factors such as Bcl-2 which can explain their reduced number. Analyzes of their development at early stages showed a pre-established bias of their low number from the CD44- stage. The study of their ontogeny has shown a sequential acquisition kinetics of CCR6 and CD138 markers to establish for the first time a model of thymic maturation of this iNKT subset which was still unknown

Immunotherapy for cancer is a young research field progressing at high speed. The first chimera of an antibody and a signaling chain was designed by Zelig Eshhar and was later further developed to enhance existing T cell therapy by combining a single-chain fragment of an antibody with the CD3 zeta chain of the TCR complex. T cells expressing these chimeric antigen receptors (CARs) could recognize and specifically kill tumor cells. However the T cells, lacked in persistence and tumor rejection did not occur. Thus, the CAR constructs have been improved by providing the T cell with costimulatory signals promoting activation. The focus of this thesis has been to evaluate second and third generation αCD19-CAR T cells for the treatment of B cell leukemia and lymphoma. B cell tumors commonly upregulate anti-apoptotic proteins such as Bcl-2, which generates therapy resistance. In the first paper a second generation (2G) αCD19-CD28-CAR T cell was combined with the Bcl-2 family inhibitor ABT-737. ABT-737 sensitized tumor cells to CAR T cell therapy and may be an interesting clinical combination treatment. In paper II, the phenotype and function of a third generation (3G) αCD19-CD28-4-1BB-CAR T cell were evaluated. B cell-stimulated CAR T cells showed increased proliferation and an antigen-driven accumulation of CAR+ T cells. 3G CAR T cells had equal cytotoxic capacity, similar lineage, memory and exhaustion profile phenotype compared to 2G CARs. However, 3G CAR T cells proliferated better and had increased activation of intracellular signaling pathways compared to 2G CAR T cells. In paper III, αCD19-CD28-4-1BB-CAR T cells were used to stimulate immature dendritic cells leading to an upregulation of maturation markers on co-cultured dendritic cells. Hence, CAR T cells may not only directly kill the tumor cells, but may induce bystander immunity that indirectly aids tumor control. This thesis also include supplementary information about the development and implementation of protocols for GMP production of CAR T cell batches for a phase I/IIa clinical trial currently ongoing for patients with refractory B cell leukemia and lymphoma. So far, two patients have safely been treated on the lowest dose.

Introdução: De origem controversa e repercussões imprevisíveis, o acometimento ovariano pela endometriose é considerado importante marcador de extensão da doença, pois pode se associar a endometriose profunda. Inúmeras teorias etiopatogênicas tentam explicar a gênese da endometriose ovariana e, duas delas recentemente tem sido reativadas, como a da metaplasia celômica que justificaria o conceito atual de endometriose intra-ovariana profunda e a da menstruação retrógrada, que explica a origem tubárea dos endometriomas. Estima-se em 5% a 10% de câncer ovariano em lesões de endometriose de ovário; enquanto, a frequência total de transformação maligna foi estimada entre 0,3 a 2,5%. Objetivo: Avaliar as formas de apresentação da endometriose ovariana e possíveis associações com o quadro clínico, com outros locais de doença, com os marcadores de atividade proliferativa (Ki-67), com a expressão de alterações moleculares dos mecanismos apoptóticos consideradas importantes no processo de carcinogênese das lesões de endometriose (p53 e Bcl-2) e com os receptores de estrogênio (dependência hormonal). Métodos: Estudo de coorte retrospectivo exploratório, com 63 pacientes operadas entre 2002 a 2012, com diagnóstico de endometriose ovariana preenchendo os critérios de inclusão e exclusão. Os preparados histológicos foram reavaliados e reclassificados de acordo com o tipo histológico, com a forma de apresentação e com a presença de infiltração do parênquima ovariano, sendo divididas em endometriose ovariana peritoneal, cistica e intraparenquimatosa. Foram avaliados a expressão do Ki-67, do p53, do Bcl- 2 e dos receptores de estrogênio no epitélio e no estroma tecidual. As pacientes ainda foram avaliadas de acordo com os sintomas clínicos e locais concomitantes de doença. Resultados: A forma de apresentação da endometriose ovariana mais frequente foi a cística (72,2%), seguida pela intraparenquimatosa (22,2%) e pela forma peritoneal (5,6%). Todas podem apresentar componente infiltrativo. A endometriose ovariana infiltrativa esteve presente em 30,5% dos casos. Não se evidenciou associação entre sintomas, distribuição anatômica do doença e expressão dos marcadores com as diferentes formas de apresentação ou com a infiltração do parênquima adjacente. Conclusão: A endometriose ovariana apresenta três formas distintas de apresentação, cística, intraparenquimatosa e peritoneal. Todas podem apresentar componente infiltrativo. Apesar da clara diferenciação histológica, ainda se deve identificar o significado clínico destes achados
Introduction: Of controversial origin and unpredictable repercussions, ovarian endometriosis is an important marker of disease extensiveness, as it may be related to deep infiltrating endometriosis. Numerous theories try to explain its origin, but two of them have been recently reactivated, such as celomic metaplasia, which would justify the concept of deep ovarian endometriosis, and retrograde menstruation, which can explain the tubal origin of ovarian endometriosis. It is estimated 5% to 10% of ovarian cancer in ovarian endometriosis, but malignant transformation may occur in 0.3 to 2.5% of the cases. Objective: Identify the presenting forms of ovarian endometrisosis and its possible relations to clinical symptoms, to other sites of disease, to proliferative activity markers (Ki-67), to the molecular expression of apoptotic mechanisms, considered important to the process of malignant transformation (p53 and Bcl-2) and to estrogen receptors (hormonal dependency). Methods: This is a retrospective exploratory cohort study, done between 2002 and 2012, including 63 women with laparoscopic diagnosis of ovarian endometriosis which fullfilled inclusion and exclusion criteria. The histologic specimens were reanalysed and reclassified according to the histologic pattern, to its presenting form and to the presence of parenchyma infiltration. The expression of Ki-67, p53, Bcl-2 and estrogen receptors were evaluated in the tissue epithelium and stroma. Clinical symptoms and concomitant sites of disease were also evaluated. Results: The most frequent form of ovarian endometriosis was cystic (72.2%), followed by intra-parenchymatous (22.2%) and peritoneal (5.6%). All of them can be infiltrative. The prevalence of infiltrative ovarian endometriosis was 30.5%. No association were found between symptoms, anatomical distribution of disease, markers expression and the presenting forms of ovarian endometriosis as well as adjacent parenchymal infiltration. Conclusion: Ovarian endometriosis has three distinct presenting forms, cystic, intra-parenchymatous and peritoneal. All of them can be infiltrative. Even though there is a clear histologic differentiation, its clinical significance is still to be determined

O diabetes mellitus tipo 1 (DM-1) e a esclerose múltipla (EM) são doenças auto-imunes órgão-específicas, inflamatórias, mediadas por células T e B auto-reativas e caracterizadas pela destruição seletiva de células b pancreáticas produtoras de insulina e do sistema nervoso central, respectivamente. Acredita-se que a desregulação da expressão de genes reguladores da maquinaria apoptótica possa contribuir para o desenvolvimento da auto-imunidade, visto que algumas dessas moléculas participam nos processos de tolerância central e periférica de linfócitos auto-reativos. O objetivo deste projeto foi analisar a expressão de moléculas reguladoras das vias intrínseca, extrínseca e da Família de proteínas inibidoras da apoptose (IAP) em 33 indivíduos saudáveis, 15 pacientes com DM-1 e 18 com EM submetidos à terapia de imunossupressão em altas doses seguida do transplante autólogo de células-tronco hematopoéticas (IAD/TACTH). As células mononucleares (CMN) foram isoladas do sangue periférico dos controles e de pacientes nos períodos pré-mobilização (pré-mob), pré-condicionamento (pré-cond), D+180, D+360, D+540 e D+720 pós-transplante. As CMN foram utilizadas para extração de RNA, síntese de cDNA, quantificação da expressão por PCR em tempo real dos genes a1, bcl-2, bcl-w, bcl-xL, mcl-1, bad, bak, bax, bid, bik, bim, bok, noxa, fas, fasL, c-FLIPL, cIAP-1 e cIAP-2 e protéica de Bcl-2, Bcl-xL, Bak, Bim e c-FLIPL por western-blotting. Os resultados de expressão gênica foram representados por unidades relativas de expressão em medianas nas diferentes amostras. Os pacientes com DM-1 apresentaram diminuição da expressão dos genes anti-apoptóticos bcl-2 (mediana: 0,98; p=0,04), bcl-w (0,08; p=0,04), mcl-1 (1254; p=0,03) e cIAP-1 (1,24; p=0,003) nas CMN dos pacientes no período pré-mob em relação aos indivíduos saudáveis (medianas: bcl-2: 7,58; bcl-w: 0,52; mcl-1: 1659; cIAP-1: 14,5), enquanto a expressão de cIAP-2 (60,8; p=0,0005) estava aumentada em relação aos controles (23,3). Foi observada redução significativa na expressão dos genes pró-apoptóticos bad (0,002; p<0,0001), bax (0,01; p=0,002) e fasL (1,66; p=0,001) no período pré-mob comparada aos controles sadios (bad: 0,23; bax: 2,79; fasL: 3,56). Os níveis de RNAm de bid (0,10; p=0,001) e bok (0,72; p=0,006) estavam elevados no pré-mob em relação ao grupo controle (bid: 0,004; bok: 0,31). As moléculas bcl-2, bcl-w, bcl-xL, mcl-1, bad, bax, bok, fasL e cIAP-1 atingiram níveis de RNAm similares aos controles após o TACTH. Foi verificado que a expressão de bcl-w, cIAP-1 e noxa estava maior nos pacientes com DM-1 em remissão quando comparados àqueles em recaída. A diminuição da expressão de a1, bcl-2 e bcl-w e o aumento de fas e noxa correlacionaram-se às porcentagens de hemoglobina glicosilada, concentração de auto-anticorpos GAD65, e aos níveis séricos de peptídeo-C após o transplante. Os pacientes com EM mostraram uma expressão reduzida dos genes anti-apoptóticos bcl-w (0,11; p=0,02) e cIAP-1 (1,87; p=0,04) no pré-mob comparada aos valores dos controles (bcl-w: 0,27; cIAP-1: 7,75) e maior expressão dos genes a1 (90,8; p=0,001) e cIAP-2 (58,8; p=0,009) em relação aos controles (a1: 12,7; cIAP-2: 22,3). As moléculas pró-apoptóticas bad (0,007; p=0,01) e bax (0,0007; p=0,004) mostraram menor expressão nas CMN no período pré-mob do que nos controles (bad: 0,27; bax: 1,24). Os genes bid (20,7; p=0,004), bik (0,84; p=0,02) e bok (1,77; p=0,0001) possuíam maior expressão no período pré-mob em relação aos indivíduos sadios (bid: 2,64; bik: 0,33; bok: 0,26). Não foram observadas diferenças significativas na expressão das moléculas da via extrínseca da apoptose nos pacientes com EM (p>0,05) nos períodos avaliados. Os valores de expressão de bcl-w, bak, bax, bik, bok e cIAP-1 atingiram níveis semelhantes aos controles após o transplante. A expressão dos genes bcl-2, cIAP-1, bad e bax estava maior nos pacientes em remissão da EM quando comparados àqueles em progressão neurológica. O aumento da expressão dos genes pró-apoptóticos bax, bak e bimEL correlacionou-se inversamente aos valores de EDSS dos pacientes com EM após o TACTH. Os resultados de expressão protéica foram equivalentes aos de expressão gênica nas duas doenças, com exceção dos dados das proteínas Bcl-2 e Bim. Em conjunto, os resultados demonstraram a desregulação da expressão de várias moléculas anti- e pró-apoptóticas nas CMN dos pacientes com DM-1 e EM. Esses achados sugerem a associação de alterações nos processos de apoptose celular com o surgimento e persistência de células auto-reativas no DM-1 e EM. Os dados indicam que essas alterações, principalmente a diminuição da expressão de moléculas pró-apoptóticas, como bak e bax, possam contribuir para a patogênese do DM-1 e EM. Além disso, a terapia de IAD/TACTH foi capaz de modular a expressão da maioria dos genes anormalmente expressos nas CMN dos pacientes com DM-1 e EM, já que esses atingiram níveis de expressão similares ao grupo controle após o transplante. Esta normalização da expressão de vários genes analisados correlacionou-se com a remissão clínica da doença na maioria dos pacientes
Type 1 diabetes mellitus (T1DM) and multiple sclerosis (MS) are inflammatory, organ-specific autoimmune diseases characterized by selective destruction of insulin-producing pancreatic -cells and central nervous system, respectively, by autoreactive B and T cells. Deregulation of apoptotic machinery is supposed to contribute to self-tolerance breakdown and autoimmune diseases pathogenesis, since apoptotic molecules have an important role in B and T lymphocytes central and peripheral tolerance mechanisms. The aim of this study was to evaluate the expression of pro and anti-apoptotic molecules from intrinsic and extrinsic apoptotic pathways and IAP Family members in 33 healthy individuals, 15 T1DM and 18 MS patients submitted to high-dose immunossupression therapy followed by autologous hematopoietic stem cell transplantation (HDI/AHSCT). Peripheral blood mononuclear cells (PBMC) were isolated from controls and patients at pre-mobilization (pre-mob), pre-conditioning (pre-cond), D+180, D+360, D+540 and D+720 post-transplantation. PBMC were used for RNA extraction, cDNA synthesis, gene quantification of a1, bcl-2, bcl-w, bcl-xL, bad, bak, bax, bid, bik, bimEL, bok, noxa, fas, fasL, c-FLIPL, cIAP-1 and cIAP-2 by Real Time PCR and Bcl-2, Bcl-xL, Bak, BimEL and c-FLIPL proteins detection by western-blotting. Results are expressed as median of relative expression units. Results from T1DM patients indicated that antiapoptotic molecules bcl-2 (median: 0,98; p=0,04), bcl-w (0,08; p=0,04), mcl-1 (1254; p=0,03) and cIAP-1 (1,24; p=0,003) were downregulated at pre-mob compared with healthy controls (medians bcl-2: 7,58; bcl-w: 0,52; mcl-1: 1659; cIAP-1: 14,5), while cIAP-2 (60,8; p=0,0005) gene expression was upregulated compared to healthy controls (23,3). We observed a significant decrease in proapoptotic bad (0,002; p<0,0001), bax (0,01; p=0,002) and fasL (1,66; p=0,001) genes expression in patients PBMC at pre-mob period compared to healthy subjects (bad: 0,23; bax: 2,79; fasL: 3,56). mRNA levels of bid (0.10; p=0.001) and bok (0.72; p=0.006) were elevated at pre-mob period when compared to control group (bid: 0.004; bok: 0.31). The bcl-2, bcl-w, bcl-xL, mcl-1, bad, bak, bax, bok, fasL and cIAP-1 mRNA levels reached controls levels after HDI/AHSCT. We observed that bcl-w, cIAP-1 and noxa gene expression were increased in T1DM patients in remission when compared to relapsed patients. The decreased antiapoptotic gene expression and increased in proapoptotic molecules correlated with decreased glicosilated hemoglobin percentages (Hb A1C) and anti-GAD65 antibodies and increased peptide-C levels. Results from MS patients showed decreased bcl-w (0,11; p=0,02) and cIAP-1 gene expression (1,87; p=0,04) in patients PBMC at pre-mob period compared to healthy controls (bcl-w: 0,27; cIAP-1: 7,75) and increased expression of a1 (90,8; p=0,001) and cIAP-2 (58,8; p=0,009) compared to controls (a1: 12,7; cIAP-2: 22,3). Proapoptotic molecules bad (0.007; p=0.01) and bax (0.0007; p=0.004) showed decreased gene expression at pre-mob compared to control group (bad: 0.27; bax: 1.24). bid (20.7; p=0.004), bik (0.84; p=0.01) and bok genes (1.77; p=0.0001) showed increased expression at pre-mob compared to healthy controls (bid: 2.64; bik: 0.33; bok: 0.26). Significant differences were not observed in the expression of the extrinsic pathway genes in pre-mob and healthy controls samples (p>0.05). bcl-w, bak, bax, bik, bok and cIAP-1 expression values reached healthy control values after transplantation. We observed that bcl-2, cIAP-1, bad and bax gene expression was increased in MS patients in disease remission when compared to patients with neurologic progression. Significant correlation of increased proapoptotic genes expression with decreased EDSS values in MS patients after HDI/AHSCT was observed. Results of protein quantification of apoptotic molecules in PBMC of T1DM and MS patients were similar to the gene expression results of these molecules, except for Bcl-2 and Bim proteins. Taken together, these data indicate a deregulated expression of anti- and proapoptotic genes in T1DM and MS patients PBMC. These data suggest an association of deregulated apoptosis with emergence and maintenance of autoreactive lymphocytes in analyzed patients. Based on these results, we suggest that this altered gene expression profile, mainly the decreased proapoptotic genes expression, as bak and bax, may contribute to T1DM and MS pathogenesis. Furthermore, we showed that the HDI/AHSCT therapy was able to modulate and normalize the expression of most genes abnormally expressed in T1DM and MS patients at pre-transplant period. Many analyzed genes achieved expression levels similar to healthy controls. The normalization of the expression of many evaluated genes correlated to disease remission in the majority of the patients.

The incidence of breast cancer is rising steadily in Sweden and the proportion of carcinoma in situ (CIS) has increased appreciably, most likely due to mammography screening. The aim of this study was twofold: (1) to examine risk factors for subsequent invasive breast carcinoma and breast cancer death after primary ductal carcinoma in situ (DCIS) and (2) to study the biology in the progress between in situ and invasive carcinoma.

In a cohort-study based on 3,398 women with a primary CIS reported to the Swedish Cancer Registry (SCR) 1980-1992, women diagnosed in 1989-1992 ran a relative risk of 0.1 (CI 95%, 0.0-0.9) from dying of breast cancer as compared with women diagnosed in 1980-1982. Women in counties with mammography screening ran a relative risk of 0.2 (CI 95%, 0.0-2.1) for breast cancer death in comparison with women in non-screening counties.

In a case-control study derived from all 4,661 women with primary CIS reported to the SCR 1960-1992, we investigated risk factors for subsequent invasive breast carcinoma (n=118) and breast cancer death (n=39). Large size and multifocality were found to increase the risk for breast cancer death. Postoperative radiotherapy and mastectomy lowered the risk for ipsilateral invasive cancer.

The standardised incidence rates (SIR) for invasive breast cancer were estimated in the cohort from 1980-1992. The SIR after primary DCIS and primary lobular carcinoma in situ (LCIS) was 4.5 (CI 95%, 3.7-5.5) and 4.0 (CI 95%, 2.1-7.5), respectively.

New histopathological classification systems for DCIS were evaluated in 195 women consecutively diagnosed with primary DCIS between 1986-1994. One group with highly differentiated lesions was defined with the EORTC classification system and had an excellent prognosis.

Histopathological grade and expression of p53, c-erbB-2, Ki 67, hormone receptors, Bcl-2 and angiogenesis were compared in 626 women with either a pure DCIS, a small invasive carcinoma or a lesion with both an invasive and in situ component. When grade was taken into account, no change in tumour markers could be detected that signalled the progression from an in situ stage to invasiveness. All tumour markers correlated to grade and their distribution was very similar in the two components of mixed lesions.

From January, 1988, to December, 1993, 113 patients with FIGO stage IA-IIC epithelial ovarian carcinoma were treated with postoperative radiotherapy. The median follow-up period was 74 months. Tumor recurrences were recorded in 33 cases (30%). The cancer-specific survival rate was 72%. Tumor grade was a significant (P = 0.007) and independent prognostic factor in the multivariate analysis. In a smaller series of 106 patients, a number of prognostic factors (age, FIGO stage, histopathological type, and tumor grade) were studied in relation to regulators of apoptosis (p53, bcl-2, and bax) and growth factor receptors (HER-2/neu and EGFR). Immunohistochemical techniques were used. In a separate series of 103 patients, the DNA content (flow cytometry) and p53 status of the tumors were also studied and related to the same clinicopathological factors. P53 was associated with tumor grade (P = 0.007) and survival status (P = 0.046). In a Cox multivariate analysis, tumor grade (P = 0.0006), bax status (P = 0.020), and EGFR status (P = 0.018) were significant and independent prognostic factors. DNA ploidy of the tumors was strongly associated with tumor grade.

From January, 1994, to December, 1998, a series of 109 patients with ovarian carcinomas (FIGO IA-IIC) were treated with postoperative adjuvant chemotherapy. The same prognostic factors were studied in this series. The median follow-up was 48 months and the cancer-specific survival rate was 75%. Twenty-five (25%) tumor recurrences were recorded. The most favorable survival rate was seen in patients with tumors negative for p53 and positive for bcl-2 or bax. In a multivariate analysis, tumor grade (P = 0.014) and p53 status (P = 0.020) were independent prognostic factors.

Clinical, histopathological and biological prognostic factors should be combined in prognostic models to render patient-tailored therapy possible and to define different prognostic groups for future clinical studies of adjuvant therapy in early stage ovarian carcinomas.

Orientador: Luiz Carlos Zeferino
Tese (doutorado) - Universidade Estadual de Campínas, Faculdade de Ciencias Medicas
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Doutorado

Endocrine resistance is a significant clinical problem in the treatment of estrogen (E2) receptor positive breast cancers. There are two ER subtypes, ERα and ERβ, which promote and inhibit breast cancer cell proliferation respectively. While ER positive breast cancers typically express a high ratio of ERα to ERβ, the acquisition of antiestrogen resistance in vitro and in vivo is associated with increased relative expression of the ERβ. On some gene enhancers ERβ has been shown to function in opposition to the ERα in the presence of E2. Here we demonstrate that exposure to two different ERβ agonists results in decreased cell viability, and produced a marked reduction in G2/M phase in antiestrogen resistant breast cancer cell line in conjunction with altered cyclin D1, and cyclin E expression relative to E2. ERβ agonists also strongly downregulated Bcl-2 expression and recruited both ERs to the Bcl-2 and pS2 E2-response elements resulting in a reduction in mRNA transcripts from both of these genes. Bcl-2 reduction correlated with increased lipidation of LC3-I to LC3-II, indicative of increased autophagic flux. Although ERβ agonist treatment alone did not induce apoptosis, remarkably, the coaddition of ERβ agonist and the autophagy inhibitor, chloroquine, resulted in robust cell death. Lastly, in vivo studies demonstrate that preferential-ERβ agonists are not estrogenic in the uterus or mammary gland. Together, these observations suggest that combined therapies including an ERβ agonist and an autophagy inhibitor may provide the basis for a safe, novel approach to the treatment of antiestrogen-resistant breast cancers.

Orientador: Lucia Helena Simões da Costa Paiva
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas
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Resumo: Introdução: Os pólipos endometriais são achados frequentes em mulheres na pós-menopausa e têm sido raramente associados a lesões precursoras e neoplasia endometrial. O desconhecimento de sua patogênese e potencial de malignidade tem levado a polipectomia de rotina o que pode estar expondo muitas mulheres a um risco cirúrgico desnecessário. Objetivo: Avaliar a prevalência de malignidade e a expressão de receptores de estrógeno e progesterona, marcadores tumorais e COX-2 em pólipos endometriais malignos e benignos em mulheres na pós-menopausa. Sujeitos e métodos: Realizou-se um estudo de corte transversal com mulheres submetidas à polipectomia no período de janeiro de 1998 a dezembro de 2008 no Hospital da Mulher "Prof. Dr. José Aristodemo Pinotti"-CAISM-UNICAMP. Foram incluídas 390 mulheres na pós-menopausa que não eram usuárias de terapia hormonal e tamoxifeno. Foram avaliadas as características clínicas como idade, sangramento pós-menopausa, paridade, presença de hipertensão arterial, diabetes mellitus, obesidade e diagnóstico histológico dos pólipos. Foi avaliada a expressão imuno-histoquímica de RE e RP e dos marcadores Bcl-2, Ki-67 e COX-2 em microarranjo de amostras teciduais (TMA). Foi comparada a expressão desses receptores e marcadores entre pólipos benignos e pré-malignos/malignos. Análise estatística: Para análise estatística os pólipos foram agrupados em benignos e pré-malignos/malignos. As características clínicas entre os grupos benignos/pré-malignos e malignos foram comparadas utilizando-se os testes qui-quadrado, exato de Fisher ou não paramétrico de Mann-Whitney. Para a comparação do escore final dos receptores e marcadores foram utilizados os testes exato de Fisher, qui-quadrado ou teste de Mann- Whitney. Resultados: A prevalência de malignidade nos pólipos endometriais em estudo foi de 7,1% e esteve associada ao sangramento pós-menopausa e à baixa expressão de RE no estroma. O escore final da expressão do RE no estroma dos pólipos foi maior nos benignos em relação aos pré-malignos/malignos, sendo esta diferença significativa. Não houve diferença de expressão do RP, Ki-67 e Bcl-2 entre os pólipos benignos e pré-malignos/malignos. O escore final da expressão da COX- 2 foi significativamente maior nos pólipos pré-malignos/malignos em relação aos benignos no epitélio glandular e no estroma. Conclusões: Os pólipos na pósmenopausa apresentam uma alta expressão dos RE no estroma e no epitélio glandular. Esta expressão foi menor nos pólipos pré-malignos/malignos em relação aos benignos. Observou-se alta expressão da COX- 2, sendo maior nos pólipos prémalignos/ malignos em relação aos benignos
Abstract: Introduction: Endometrial polyps are common findings in postmenopausal women that are rarely associated with precursor lesions and endometrial neoplasm. Lack of understating of the pathogenesis and oncogenic potential of polyps has led to the routine performance of polypectomy which may expose many women to unnecessary surgical risks. Objective: To evaluate the prevalence of malignancy and expression of estrogen/progesterone receptors, tumor markers and COX-2 in malignant and benign endometrial polyps in postmenopausal women. Subjects and Methods: A cross-sectional study was conducted with women undergoing polypectomy from January 1998 to December 2008 in the "Prof. Dr. José Aristodemo Pinotti" Women's Hospital-CAISM-UNICAMP. Included in the study were 390 postmenopausal women who were non-users of hormone therapy and tamoxifen. Clinical characteristics such as age, postmenopausal bleeding, parity, presence of arterial hypertension, diabetes mellitus, obesity and histologic diagnosis of polyps were assessed. Immunohistochemical expression of ER/PR, Bcl-2, Ki-67 and COX-2 markers in tissue microarray (TMA) samples was evaluated. A comparison of these receptors and markers was made between benign and premalignant/malignant polyps. Statistical analysis: For statistical analysis, polyps were grouped into benign and premalignant/malignant. Clinical characteristics between the benign/premalignant group and the malignant group were compared using the chi-square, Fisher exact or Mann-Whitney nonparametric test. To compare the final score of receptors and biomarkers, the Fisher exact tests, chi-square or Mann-Whitney test were used. Results: The prevalence of malignancy in endometrial polyps in the study was 7.1% and was associated with postmenopausal bleeding and low ER expression in the stroma. The final score of ER expression in the stromal component of the polyp was higher in benign polyps than in premalignant/malignant and this was a significant difference. There was no difference in PR, Ki-67 and Bcl-2 expression between benign and premalignant/malignant polyps. The final score of COX-2 expression was significantly higher in premalignant/malignant polyps in comparison to benign polyps in the glandular epithelium and stroma. Conclusions: Polyps in the postmenopause show a high ER expression in the stroma and glandular epithelium. Expression was lower in premalignant/malignant polyps than in benign polyps. Elevated COX-2 expression was observed that was higher in premalignant/malignant polyps than in benign polyps
Doutorado
Fisiopatologia Ginecológica
Doutor em Ciências da Saúde

Hiperplasia Prostática Benigna (HPB) é uma condição patológica que acomete os homens na senescência e está presente em 50% da população masculina, com cerca de 85 anos de idade. A glândula prostática é alvo dos hormônios androgênicos que são responsáveis pela diferenciação e crescimento do epitélio e estroma prostáticos. Os mecanismos proliferativos da próstata envolvem uma série de fatores que operam em conjunto para manter o equilíbrio entre inibição e/ou proliferação celular. Este trabalho teve como objetivo investigar os mecanismos moleculares mediados por androgênio que possam estar envolvidos na proliferação de células epiteliais prostáticas humanas derivadas de HPB. As células foram incubadas com diferentes concentrações de dihidrotestosterona (DHT). Uma baixa concentração de DHT (10-13 M) provocou um aumento significativo na proliferação destas células. Para se verificar se o efeito proliferativo ocorre via receptor de androgênio (AR), as células foram tratadas com o antiandrogênio hidroxiflutamida e a proliferação foi inibida. A expressão do gene do AR foi avaliada por RT-PCR em diferentes tempos de tratamento e concentrações de DHT. Os níveis de mRNA do AR aumentaram significativamente nos grupos tratados com DHT.10-13 M em 3, 4 e 6 horas de estímulo hormonal, sendo que um aumento marcante na expressão do AR foi observado em 4 horas de tratamento. Em relação às diferentes concentrações de DHT testadas no tempo de 4 horas (DHT.10-8, DHT.10-10 e DHT.10-13 M), a expressão do AR aumentou significativamente no grupo tratado com DHT.10-13 M em relação ao grupo controle. Buscando averiguar o possível papel de genes envolvidos na proliferação celular que podem ser modulados pela ação androgênica, em células epiteliais prostáticas, avaliou-se também por RT-PCR a expressão do p21 e do bcl-2. A expressão gênica do p21 foi verificada no intervalo de tempo de zero à 6 horas de tratamento com DHT.10-13 M, não apresentando diferença em seus níveis de mRNA nos tempos avaliados. Quando as células foram incubadas durante 4 horas com diferentes concentrações de DHT, observou-se que a concentração mais alta (10-8 M) provocou um aumento significativo nos níveis de mRNA do p21 em relação ao grupo tratado com DHT.10-13 M. O gene do bcl-2 teve sua expressão avaliada no mesmo intervalo de tempo do p21. Os níveis de mRNA do bcl-2 aumentaram significativamente em 15 minutos de tratamento com DHT.10-13 M em relação ao tempo zero e aos grupos tratados por 1 e 4 horas. Os dados obtidos neste trabalho indicam que baixas concentrações de dihidrotestosterona estimulam a proliferação das células epiteliais prostáticas derivadas de HPB, por uma via que parece envolver a expressão do AR, do p21 e do bcl-2.

Leucemia mieloide crônica (LMC) é uma neoplasia hematológica maligna associada à atividade tirosinoquinase da oncoproteína BCR-ABL1. A maioria dos casos de LMC é tratada com sucesso com inibidores tirosinoquinase de BCR-ABL1, mas uma porcentagem significativa de pacientes desenvolve resistência ao fármaco. Estudos recentes indicam que a célula-tronco leucêmica é resistente ao tratamento com imatinibe. A identificação de outras proteínas que cooperam com as vias de sinalização BCR-ABL1 podem indicar novos alvos terapêuticos. Os substratos do receptor de insulina (IRS) têm emergido como proteínas importantes na fisiopatologia de neoplasias sólidas e hematológicas. Um inibidor farmacológico de IGF1R-IRS1/2, NT157, foi desenvolvido e mostrou resultados promissores em estudos pré-clínicos com tumores sólidos. A associação constitutiva de IRS1 com BCRABL1 e o efeito antineoplásico resultante do silenciamento espefício de IRS1 em células K562 BCR-ABL1+ suportam a hipótese deste trabalho. O objetivo do presente estudo foi investigar o efeito da inibição farmacológica de IGF1R-IRS1/2 no fenótipo de células hematopoéticas leucêmicas BCR-ABL1+ utilizando células primárias, células K562 e modelos murinos. IRS1, mas não IRS2, apresentou-se menos expresso em amostras de medula óssea de pacientes com diagnóstico de LMC quando comparadas às amostras de células hematopoéticas normais (p<0,0001). NT157 reduziu a formação de colônias de células primárias de pacientes com LMC, mas não de células hematopoéticas de indivíduos saudáveis. Em células K562, o tratamento com o inibidor farmacológico de IGF1R-IRS1/2, NT157, reduziu a viabilidade e proliferação celular e induziu apoptose (p<0,05), inibiu a fosforilação de IGF1R, STAT3, STAT5, 4EBP1, P70S6K e ERK1/2, aumentou a expressão dos genes supressores de tumor CDKN1A, FOS e JUN e reduziu a expressão dos oncogenes MYC e BCL2 (p<0,05); a inibição específica de IRS1 através de lentivírus, mas não de IRS2, reduziu a viabilidade celular (p<0,05). Em células murinas Ba/F3 BCR-ABL1 e BCRABL1T315I, o inibidor farmacológico de IGF1R-IRS1/2, NT157, induziu apoptose e reduziu ativação de ERK1/2 in vitro. Na dose de 50mg/kg/dia, NT157 intraperitoneal e/ou imatinibe por gavagem falharam em reduzir o crescimento tumoral in vivo em modelo de tumor alográfico induzido por células Ba/F3 BCR-ABL1 e BCR-ABL1T315I. Em modelo animal de leucemia induzido por transplante de células hematopoéticas transduzidas com BCR-ABL1: (i) o tratamento com NT157 100mg/kg intraperitoneal, 3 vezes por semana, combinado com imatinibe 100mg/kg/dia por gavagem, reduziu significativamente o peso do baço, e preveniu a perda de peso comparado com veículo (p<0,05); apenas a monoterapia com imatinibe prolongou a sobrevida dos animais, (ii) o tratamento com NT157 70mg/kg intraperitoneal, 3 vezes por semana, e/ou imatinibe 70mg/kg/dia por gavagem não teve impacto no peso do baço e na variação do peso corporal; o tratamento com imatinibe em monoterapia ou combinado com NT157 prolongou a sobrevida dos animais (p<0,05). Em conclusão, o inibidor farmacológico de IGF1R-IRS1/2 representa uma droga potencialmente eficaz no tratamento da LMC, especialmente em casos de resistência com mutação BCR-ABL1 T315I. A avaliação da eficácia do inibidor farmacológico NT157 em modelos animais de LMC exige ajustes nos modelos murinos utilizados no presente estudo, melhor entendimento da farmacodinâmica e farmacocinética do composto e ajustes no esquema terapêutico utilizado.
Chronic myeloid leukemia (CML) is a hematological malignancy associated with the tyrosine kinase activity of the BCR-ABL1 oncoprotein. Most cases of CML are successfully treated with BCR-ABL1 tyrosine kinase inhibitors, but a significant percentage of patients develop resistance. Recent studies indicate that leukemic stem cell is resistant to imatinib treatment. The identification of other proteins that cooperate with the BCR-ABL1 signaling pathway may indicate novel therapeutic targets. Insulin receptor substrates (IRS) have emerged as important proteins in the pathophysiology of solid and hematological neoplasms. A pharmacological inhibitor of IGF1R-IRS1/2, NT157, has been developed and shown promising results in preclinical studies with solid tumors. The constitutive association of IRS1 with BCR-ABL1, and the antineoplastic effects resulting from IRS1-specific silencing in K562 BCR-ABL1+ cells, support the hypothesis of this work. The aim of the present study was to investigate the effect of pharmacological inhibition of IGF1R-IRS1/2 on the phenotype of BCR-ABL1+ leukemia cells, using primary cells, K562 cell line and murine models. IRS1, but not IRS2, was downregulated in bone marrow samples from CML patients compared to bone marrow cells from healthy donors (p<0.0001). NT157 reduced colony formation of primary cells from CML patients but not from healthy donors. In K562 cells, treatment with the pharmacological inhibitor IGF1R-IRS1/2, NT157, reduced cell viability and proliferation, induced apoptosis (p<0.05), inhibited the phosphorylation of IGF1R, STAT3, STAT5, 4EBP1, P70S6K and ERK1/2, increased expression of tumor suppressor genes CDKN1A, FOS and JUN, and reduced expression of oncogenes MYC and BCL2 (p<0.05); IRS1 silencing mediated by lentivirus, but not IRS2, reduced cell viability (p<0.05). In murine Ba/F3 BCRABL1 and Ba/F3 BCR-ABL1T315I cells, the pharmacological inhibitor of IGF1R-IRS1/2, NT157, induced apoptosis and reduced ERK1/2 activation in vitro. At 50mg/kg/day, NT157 intraperitoneally and/or imatinib orally, failed to reduce tumor burden in vivo in an allographic tumor model induced by Ba/F3 BCR-ABL1 and Ba/F3 BCR-ABL1T315I cells . In an animal leukemia model induced by transplantation of BCR-ABL1-transduced hematopoietic cells : (i) treatment with NT157 100mg/kg intraperitoneally, 3 times per week, combined with imatinib 100mg/kg/day per gavage, significantly reduced spleen weight, and prevented weight loss compared to vehicle (p<0.05); only imatinib monotherapy prolonged survival (p<0.05), (ii) treatment with NT157 70 mg/kg intraperitoneally, 3 times per week, and/or imatinib 70 mg/kg/day per gavage had no impact on spleen weight and body weight; treatment with imatinib alone or combined with NT157 prolonged survival (p<0.05). In conclusion, the pharmacological inhibitor of IGF1R-IRS1/2 represents a potential effective drug in CML therapy, especially in cases of resistant BCR-ABL1 T315I mutation. The evaluation of the NT157 pharmacological efficacy in CML animal models requires adjustments in the murine models used in the present study, better understanding of the pharmacodynamics and pharmacokinetics of the compound and adjustments in the therapeutic scheme used.

Orientadores: Ilza Maria Urbano Monteiro, Cristina Laguna Benetti Pinto
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas
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Resumo: Introdução: Após a menopausa, o ganho de peso e a distribuição dos depósitos de gordura podem estar alterados com o predomínio da gordura abdominal, favorecendo o aparecimento de doenças metabólicas e neoplásicas. O mecanismo pelo qual a obesidade promove o aparecimento destas doenças ainda não está totalmente esclarecido. No entanto, sugere-se que a produção de estrogênios, decorrentes da conversão dos andrógenos no tecido adiposo e os efeitos metabólicos relacionados à hiperinsulinemia, mediados pelo IGF-1, possam estar relacionados. Embora se espere que o endométrio após a menopausa esteja atrófico, existe uma proporção que mantém padrão proliferativo fraco, provavelmente como resposta ao baixo e constante estímulo estrogênico. O objetivo deste estudo é avaliar a associação existente entre a expressão de receptores esteróides, IGF-1, Bcl-2 e Ki-67 no endométrio, correlacionando-os com índice de massa corporal e resistência tecidual insulínica. Sujeitos e Métodos: Foi realizado estudo de corte transversal, sendo selecionadas 85 mulheres após a menopausa, do Centro de Atenção Integral à Saúde da Mulher (Caism - Unicamp) e do Hospital Dr. José de Carvalho Florence (São José dos Campos-SP). Foram avaliados os receptores endometriais para estrogênio (RE), progesterona (RP), fator de crescimento insulinóide 1 (IGF-1), Ki-67 e Bcl-2 na amostra endometrial obtida correlacionando-os com a resistência tecidual insulínica (RI) e índice de massa corporal (IMC). Os dados foram analisados através dos testes de Pearson e de Spearman, considerando-se o valor ? de 0,05. Resultados: Obtivemos 36,5% de mulheres com sobrepeso e 40% com obesidade. Não foi encontrada correlação estatística entre IMC com variável estudada. Observou-se expressão moderada e intensa para os RE (94,1%), RP (80%) e IGF-1R (78,8%) nas glândulas endometriais. A expressão do Ki-67 foi moderada e intensa em 75,3% e Bcl-2 em 65,9% das amostras. O índice HOMA-IR correlacionou-se com os RE (p=0,0402) e RP (p=0,0034). Os IGF-IR e RP se correlacionaram com CA (p=0,0189 e 0,0170) respectivamente. Observou-se correlação entre RE, RP e Ki-67 e Bcl-2. Conclusão: Mulheres após a menopausa apresentam grande expressão endometrial dos receptores estrogênicos, progestogênicos e IGF-1, independentemente do seu peso corporal ou do índice de massa corporal. Houve correlação entre os RE, RP e IGF-1R com marcadores de resitência tecidual insulínica
Abstract: Introduction: After menopause, weight gain and the distribution of fat deposits may be altered with a predominance of abdominal fat, favoring the development of metabolic diseases and cancer. The mechanism by which obesity promotes the onset of these diseases is not fully understood. However it is suggested that the production of estrogens, resulting from the conversion of androgens in adipose tissue and metabolic effects associated with hyperinsulinemia, mediated by IGF-1, may be related. While is hoped that the postmenopausal endometrium is atrophic, there is a proportion that maintains low proliferative index, probably in response to low estrogen and constant encouragement. The aim of this study is to evaluate the association between the expression of steroid receptors, IGF-1, Bcl-2 and Ki-67 in the endometrium, correlating them with body mass index and insulin resistance tissue. Subjects and Methods: Was conducted cross-sectional study, were 85 selected women after menopause, in the Center for Integral Attention to Women's Health (Caism - Unicamp) and the Hospital Dr. José de Carvalho Florence (São José dos Campos-SP). We evaluated the endometrial receptors for estrogen (ER), progesterone (PR), IGF-1, Ki-67 and Bcl-2 in endometrial sample obtained by correlating them with tissue insulin resistance (IR) and body mass index (BMI). Data were analyzed using Pearson tests and Spearman, considering ? value of 0.05. Results: We obtained 36.5% of overweight women and 40% were obese. We don't found statistical correlation between body mass index with no variable studied. We observed moderate to intense expression for ER (94.1%) PR (80%) and IGF-1R (78.8%) in the endometrial glands. The expression of Ki-67 was moderate and severe in 75.3% and Bcl-2 in 65.9% of samples. The index of HOMA-IR was correlated with the ER (p = 0.0402) and PR (p = 0.0034). The IGF-IR and PR were correlated with CA (p = 0.0189 and 0.0170) respectively. There was a correlation between ER, PR and Ki-67 and Bcl-2. Conclusion: Women after menopause have a great expression of endometrial estrogen, progestin and IGF-1 receptors, independent of their BMI. There was a correlation between the ER, PR and IGF-1R with tissue insulin resistance markers
Doutorado
Fisiopatologia Ginecológica
Doutor em Tocoginecologia

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FAPESB; CAPES
Introdução: O fato de apenas 10% das pessoas infectadas com M. tuberculosis desenvolverem a doença clínica sugere que fatores genéticos podem desempenhar um papel importante na patogênese da TB. Polimorfismos em genes de citocinas têm sido associados com susceptibilidade, gravidade e variação na resposta clínica em várias doenças, incluindo doenças infecciosas. Para combater a doença, a única vacina licenciada para uso contra a tuberculose é o Bacilo de Calmette-Guérin (BCG). A proteção induzida pela vacinação contra o M. tuberculosis é mediada pela geração de células T específicas e produção aumentada de IFN-γ. Objetivo: Avaliar a associação entre o polimorfismo de genes de citocinas e receptores em voluntários sadios revacinados com BCG ao perfil de resposta in vitro a antígenos micobacterianos. Metodologia: 25 voluntários com resultados negativos ao teste tuberculínico em dupla testagem (que fizeram parte de um estudo de revacinação com Bacilo de Calmette-Guérin, cepa Moreau), foram recrutados para o estudo. As citocinas IFN-γ, TNF, IL-10, IL-6 e IL-1β foram avaliadas no sobrenadante das culturas de sangue total estimuladas com antígenos do M. tuberculosis. Os polimorfismos de interesse IFNG +874T>A, IL10- 592C>A, IL1B-35C>T, TLR2 G753A (Arg753Gln) e TLR4 C399T (Thr399Ile) foram amplificadas por reação em cadeia da polimerase (PCR) e a análise dos polimorfismos foram identificados por tamanho dos fragmentos de restrição (PCR-RFLP) ou Amplificação pelo Sistema de Mutação Refratária (ARMS-PCR). Resultados: Não houve diferença significativa na produção das citocinas IFN-γ, IL-10, TNF, IL-6 e IL-1β antes ou após a revacinação com BCG entre os diferentes genótipos dos polimorfismos estudados. Discussão e Conclusão: No presente estudo, foi observado que o aumento da produção de IFN-γ (estudo de revacinação com Bacilo de Calmette-Guérin, cepa Moreau) após a revacinação de indivíduos saudáveis com BCG não foi influenciada por polimorfismos previamente associados com resistência e/ou susceptibilidade ao desenvolvimento da tuberculose em outras populações.
Salvador

Die Wirkung von zwei endogen neuroprotektiven Substanzen, Melatonin und 17 beta-Estradiol wurde an drei Caspase-abhängigen, apoptotischen, aber Exzitotoxin-unabhängigen Schadensmodellen an neuronalen Primärkulturen untersucht und mit der bei vorwiegend nekrotischen Schadensmodellen verglichen. Es zeigten sich eine Abhängigkeit des neuroprotektiven Potentials von der Art des Zelluntergangs sowie unterschiedliche Mechanismen der Neuroprotektion. Melatonin wirkte in allen drei apoptischen Modellen nicht neuroprotektiv, sondern verstärkte die Schädigung der Neurone noch, während partiell gegen die OGD-induzierte Nekrose (OGD, engl. Oxygen glucose deprivation, kombinierter Sauerstoff- und Glukoseentzug) kortikaler Neurone Schutz erzielt wurde. Der Einsatz des endogenen neuroprotektiven Faktors Melatonin als Therapeutikum ist möglicherweise nur bei neurodegenerativen Erkrankungen mit exzitotoxischer Schädigung durch Glutamat oder oxidativem Stress wie bei Epilepsie oder dem Schlaganfall durch Ischämie sinnvoll. Die fehlende bzw. potenzierenden Wirkung von Melatonin bei neuronaler Apoptose in vitro, stellt jedoch einen therapeutischen Erfolg bei der Behandlung der mit apoptotischer Schädigung einhergehenden Alzheimer'schen Erkrankung in Frage. Bei klinischer Anwendung ist auch der von uns erhobene Befund zu beachten, dass in vitro native neuronale Zellen durch Melatonin geschädigt werden. 17 beta-Estradiol wirkte sowohl bei nekrotischer als auch bei apoptotischer Zellschädigung. Dabei zeigten sich wesentliche Unterschiede in den Mechanismen der Neuroprotektion und in der Ansprechbarkeit verschiedener Regionen des Gehirns. Schutz vor Apoptose konnte nur durch eine Langzeitvorbehandlung (20 h) in septalen und hippokampalen Kulturen, nicht jedoch in kortikalen Kulturen beobachtet werden. Dieser Effekt liess sich durch Rezeptorantagonisten, Proteinsynthesehemmung sowie durch Hemmung der Phosphoinositol-3-Kinase blockieren. Eine Kurzzeitbehandlung war gegen Apoptose nicht wirksam, zeigte gegen OGD und Glutamattoxizität jedoch neuroprotektives Potential. Dieser Effekt liess sich nicht antagonisieren, so dass hier ein direkter antioxidativer Mechanismus wahrscheinlich erscheint. Die antiapoptotische Wirkung in septalen und hippokampalen Kulturen korrelierte mit einer höheren Dichte des Estrogenrezeptors-alpha und einer erhöhten Expression antiapoptotischer Proteine in diesen Regionen. Da bei der Alzheimer'schen Erkrankung der Kortex betroffen ist, könnte der fehlende Effekt von 17 beta-Estradiol in kortikalen Neuronen sowohl auf die neuronale Apoptose als auch auf die Proteinexpression von Bcl-2 und Bcl-xL möglicherweise auf experimenteller Basis erklären, warum eine langfristige Estrogentherapie bei Frauen mit milder bis moderater Alzeimer'scher Erkrankung den Progress der Erkrankung nicht aufhalten konnte (Mulnard et al. 2000).
The neuroprotective effect of melatonin and 17 beta-estradiol has been evaluated in several in vitro models of neuronal apoptosis and necrosis. Melatonin was not neuroprotective in three models of apoptosis but showed a pro-apoptotic effect in primary cortical neurons. Melatonin revealed to damage naïve neurons, too. Partial protection was observed against necrotic neurodegeneration after oxygen-glucose deprivation (OGD). The use of melatonin as a therapeutic agent might be of interest in neurodegenerative diseases with excitotoxic damage like epilepsia or ischemia, but is questioned in case of apoptotic neurodegeneration. 17 beta-estradiol was neuroprotectiv in both necrotic and apoptotic neurodegeneration. Differences in the mechanism of neuroprotetion and in the efficacy in different regions of the brain were observed. A neuroprotective effect was visible only in hippocampal and septal cultures if 17 beta-estradiol was applied 20 h prior (long term pre-treatment) but not in cortical neurons. This effect correlates with an increased density of estrogen receptor-alpha and an increased expression of anti-apoptotic proteins like Bcl-2 and Bcl-xL in these regions. These effect could be blocked with receptor antagonists, protein synthesis inhibitors and an inhibitor of the phosphatidylinositol 3-kinase. A short term pre-treatment revealed a receptor independent neuroprotective potential against OGD and glutamate toxicity. The failure of 17 beta-estradiol to protect cortical neurons against apoptosis could be an experimental basis to understand, why a long lasting treatment with estrogens of women with mild to moderate Alzheimer´s disease failed to inhibit the progress of the illness (Mulnard et al., 2000)

Le cancer de l'endomètre est le cancer gynécologique le plus fréquemment diagnostiqué chez les femmes en Europe, aux USA et au Japon. Les mécanismes de carcinogenèse endométriale sont encore mal appréhendés et les facteurs histopronostiques classiques ne permettent pas toujours de prédire le risque évolutif. Dans ce travail, l’étude de l’expression des métalloprotéases (MMP-2,-7 et -9) et des inhibiteurs tissulaires des métalloprotéases (TIMP-1 et -2) suggère l’implication de ce système enzymatique dans le processus de carcinogenèse endométriale avec un profil d’expression différent dans l’endomètre normal, l’hyperplasie et le cancer de l’endomètre. Nous avons par ailleurs pu montrer que l’analyse de l’expression de MMP-2 (gélatinase A) et de TIMP-2 permettait de définir un sous-groupe de cancer de l’endomètre qui était particulièrement à risque d’extension locale et à distance. Nos résultats ont également permis de confirmer le rôle prépondérant de la perte d’hétérozygotie (LOH) de TP53 dans la genèse des cancers de l’endomètre de type II et la survenue plus tardive de cet évènement dans les cancers de l’endomètre de type I (hormonodépendants). En terme de pronostic, l’analyse du gène TP53 par FISH (hybridation par fluorescence in situ) n’est pas supérieure à celle obtenue par IHC (immunohistochimie). Enfin, l’étude des corrélations histopronostiques réalisée dans ce travail suggère que l’évaluation conjointe de la ploïdie, de MMP-2 et TIMP-2, de p53, du Ki67 et des récepteurs hormonaux (E et P) sur les prélèvements tissulaires pourrait mieux définir une population à haut risque évolutif pouvant bénéficier de thérapeutique ciblée.

Clomiphene citrate (CC) is a synthetic oestrogen receptor modulator that may act to promote or inhibit oestrogenic responses depending on the type of tissue or organism. CC acts as a superovulator and has been widely prescribed in the treatment of female infertility. However, pregnancy rates after CC treatment are low, possibly due to the CC causing morphological and other unidentified changes to the uterus. This study investigated the changes caused by CC on the progesterone receptor (PR), the anti-apoptotic protein, Bcl-2, and the pro-apoptotic protein, Bax. PR with its ligand, progesterone, is important for the maintenance of a pregnancy. Bcl-2 is a cell survival molecule and acts in opposition to Bax, which promotes apoptosis, which is important in allowing an attaching blastocyst to infiltrate the maternal endometrium. A high physiological dose of CC (1.25 mg) was administered to ovariectomised rats, either as a single treatment, or prior to a hormonal treatment regime characteristic of pre-implantation animals. The single CC treated animals were compared with single 5 mg progesterone (P4) treated animals and vehicle controls. The animals treated with CC in conjunction with the ovarian hormone milieu (CCPPPE treatment) were compared to PPPE treated animals or to the vehicle controls. The effects of CC, P4, PPPE and SPPPE on the morphology of the uteri were investigated by light microscopy. Expression of the PR, Bcl-2 and Bax were investigated using immunohistochemistry and enzyme linked immunosorbent (ELISA) techniques. The present study showed that CC treatment affects the microanatomy of the uterine compartments, particularly the shape of the lumen and the luminal epithelial height. The expressions of PR, Bcl-2 and Bax in the entire uterus were not significantly affected by the various treatments applied to the ovariectomised rats, as measured using ELISA. However, expression of the proteins in the various uterine compartments was altered by CC treatment. The single CC and CCPPPE treatments had an oestrogenic effect with regards to PR expression in the uteri as seen in the immunolocalisation, whereas the single P4 treatment decreased the PR expression, as expected. CC treatment caused patchiness in both Bcl-2 and Bax expression surrounding the endometrial lumen. Moreover, treatment with CC maintained expression of Bcl-2 in the luminal epithelium, whereas the expression of Bax shifted away from the luminal epithelium. This suggests that CC treatment promotes cell survival of the luminal epithelium, which may diminish the ability of the blastocyst to infiltrate the maternal tissue. CC action is both dose sensitive and has a cumulative effect with multiple treatments. Future studies would aim to separate the various uterine compartments in order to quantitatively assess the actions of CC on expression in the PR, Bcl-2 and Bax. In addition, it would be interesting to investigate how the accumulation of subsequent CC doses affects the expression of apoptotic markers, as this would be a more realistic model for human infertility treatment.

碩士
國立臺灣大學
獸醫學研究所
91
Canine mammary gland tumors (MGTs) are the most frequent neoplasm in bitches. The etiology of mammary tumors in dog is multifactorial involvement and hormones dependent. The hormone factor is considered the most important factor in the development of mammary tumors. In addition, a balance between proliferation, differentiation, and death of the cells is critical for normal development and homeostasis of the mammary gland. Loss of balance may allow accumulation of mutations that result in MGT. Therefore, the aim of this study is to analyze and correlate the expression of estrogen receptor and Bcl-2 protein, proliferative activity and apoptosis in canine MGTs. Thirty-three female dogs with 39 surgically excised MGT specimens from Department of Surgery, National Taiwan University Veterinary Hospital (NTUVH) were collected for basic information analysis, immunohistochemistry (IHC) of ER, Bcl-2 protein, Ki67 antigen, and TUNEL assay. The mean age of MGT affected dogs was 10.4 years old. Mixed species (17/33; 51.5%) was the most common breed in this study, the next was Maltese (6/33; 18.2%). 69.7% (22/33) of canine MGTs occurred in gland 4 and 5. The ratio of benign and malignant tumors was 4: 6. The results of IHC showed 79.5% (31/39) of MGTs with positive expression of ER, including all of benign tumors and 66.7% (16/24) of malignant tumors. Benign tumors had more expression of ER than malignant tumors (p<0.01). Bcl-2 protein was detected in 61.5% (24/39) of MGTs which included 66.7% (10/15) of benign tumors and 58.3% (14/24) of malignant tumors. There was no significant difference in Bcl-2 expression between benign and malignant tumors. Malignant tumors showed more growth fraction and AI value than benign tumors (p<0.01), and the TUNEL index of all specimens examined was less than 1%. The analysis of correlation displayed that the expression of ER seemed to be positively related with Bcl-2 expression like those reported in breast cancer. However, there was no statistically significant correlation. The degree of cell proliferation and apoptosis were not significantly correlated to the expression of Bcl-2. There was positive relationship between cell proliferation and apoptosis, but negative correlation between ER and cell proliferation. In conclusion, the positive correlation between ER and Bcl-2 in canine MGTs suggested ER may be the regulator of Bcl-2 protein as seen in human breast cancer. In addition, there were more and stronger ER and Bcl-2 expression but less cell proliferation and apoptosis in benign MGTs. In contrast to benign tumors, malignant tumors had decreased ER and Bcl-2 expression or intensity but increased proliferation and apoptosis. It is hypothesized that decreased dependence of estrogen, the effect of anti-apoptosis, and increased cell proliferation and apoptosis occur in tumor progression or malignancy of canine MGTs.

Nur77 is a member of the orphan nuclear receptor family, where it is known to play an important role in apoptosis in both negative selection in T cells and in cancer cell lines. In the development of T cells, it is critical for the immune system to discriminate self from non-self by eliminating auto-reactive cells. It was originally thought that Nur77 initiated apoptosis by activating downstream gene targets. However, it is now clear that Nur77 has its own distinct role outside of the nucleus and the precise mechanisms by which Nur77 induces apoptosis in T cells still needs to be clarified. Calcium plays an important role as a second messenger in various cellular responses, one of which includes apoptosis. The IP3 receptor controls efflux of calcium from the ER and can be activated through TCR activation. This signal induces a rise in cytoplasmic calcium levels ultimately causing cell death through mechanisms that remain unclear. Here, we use a double positive DO11.10 T cell line with tetracycline responsive Nur77, to examine the effects of cytosolic Nur77. Through co-immunoprecipitation experiments we suggest, that the presence of Nur77 disrupts the IP3R/Bcl-2 interaction. In this study, we also investigated the effect of Nur77 on intracellular calcium levels. We show that Nur77 increases baseline calcium levels and causes emptying of ER calcium stores. We suggest a model where cytosolic Nur77 disrupts the IP3R/Bcl-2 interaction by binding Bcl-2 at the mitochondria or ER, causing calcium release through the IP3R and apoptosis of the cell.

碩士
高雄醫學大學
臨床醫學研究所
101
Apigenin, a naturally occurring plant flavone, may have chemopreventive and therapeutic potentials as an anti-inflammatory, antioxidant and apigenin against malignant tumors. However, the anti-tumor effect of apigenin on human head and neck squamous cell carcinoma (HNSCC) is not fully understood. In this study, apigenin inhibits cell growth and induces cell cycle arrest during the G2/M phase in well differentiated HNSCC SCC25 cells and epidermoid carcinoma A431 cells. Apigenin has cancer preventive properties, antioxidant capacity, ability to inhibit lipid peroxidation, and protective murine normal embryonic liver BNLCL2 cells against oxidative damage. Apigenin increased intracellular reactive oxygen species (ROS) levels, depleted intracellular-reduced glutathione (GSH), and induced cell apoptosis via tumor necrosis factor receptor (TNF-R), TNF-related apoptosis-inducing ligand receptor (TRAIL-R), and Bcl-2-mediated caspase-dependent cell death pathways in SCC25 cells but Fas signal is not. The combination of apigenin with 5-fluorouracil (5-Fu) or cisplatin dramatically increased death of SCC25 cells in a dose-dependent manner; this property may be exploited to reverse HNSCC insensitivity to 5-Fu and cisplatin. These analytical findings suggest that apigenin may be a good candidate for additional evaluation as a cancer therapeutic agent against HNSCC cells.

Breast cancer is the second leading cause of death due to cancer in women. A number of effective therapeutic strategies have been implemented in clinics to cope with the disease yet recurrent disease and toxicity reduce their effectiveness. Hence, there is a need to identify and develop more effective therapies with reduced toxic side effects to improve overall survival rates. This dissertation investigates the mechanisms of action of two natural forms of vitamin E and a cholesterol lowering drug, simvastatin, as a therapeutic strategy in human breast cancer cells. Vitamin E in nature consists of eight distinct forms which are fat soluble small lipids. Until recently, vitamin E was known as a potent antioxidant but emerging work suggests they may be resourceful agents in managing a number of chronic diseases including cancer. Anticancer properties of vitamin E have been identified to be limited to the γ- and δ- forms of both tocopherols and tocotrienols. Gamma-tocopherol ([gamma]T) and gamma-tocotrienol ([gamma]T3) have both already been identified to induce death receptor 5 (DR5) mediated apoptosis in breast cancer cells. Studies here show that similar to [gamma]T3, [gamma]T induced DR5 activation is mediated by c-Jun N-terminal kinase/C/EBP homologous protein (JNK/CHOP) proapoptotic axis which in part contributed to [gamma]T mediated dowregulation of c-FLIP, Bcl-2 and Survivin. Also, both agents activate de novo ceramide synthesis pathway which induces JNK/CHOP/DR5 proapoptotic axis and downregulates antiapoptotic factors FLICE inhibitory protein (c-FLIP), B-cell lymphoma 2 (Bcl-2) and Survivin leading to apoptosis. Simvastatin (SVA) has been identified to display pleiotropic effects including anticancer effects but mechanisms responsible for these actions have yet to be fully understood. In this dissertation, it was observed that simvastatin induced apoptosis in human breast cancer cells via activation of JNK/CHOP/DR5 proapoptotic axis and down regulation of antiapoptotic factors c-FLIP and Survivin which are in part dependent on JNK/CHOP/DR5 axis. The anticancer effects mediated by simvastatin can be reversed by exogenously added mevalonate and geranylgeranyl pyrophosphate (GGPP), implicating the blockage of mevalonate as a key event. Furthermore, work has been done to understand the factors responsible for drug resistance and identify therapeutic strategies to counteract the same. It was observed that development of drug resistance was associated with an increase in the percentage of tumor initiating cells (TICs) in both tamoxifen and Adriamycin resistant cells compared to their parental counterparts which was accompanied by an increase in phosphorylated form of Signal transducer and activator of transcription 3 (Stat3) proteins as well as its downstream mediators c-Myc, cyclin D1, Bcl-xL and Survivin. Inhibition of Stat3 demonstrated that Stat3 and its downstream mediators play an important role in regulation of TICs in drug resistant breast cancer. Moreover, SVA, [gamma]T3 and combination of SVA+[gamma]T3 has been observed to target TICs in drug resistant human breast cancer cells and downregulate Stat3 as well as its downstream mediators making it an attractive agent to overcome drug resistance. From the data presented here, the mechanisms responsible for the anticancer actions of [gamma]T, [gamma]T3 and SVA have been better understood, providing the necessary rationale to test these agents by themselves or in combination in pre-clinical models.
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