Au cours de ces dernières décennies, l’augmentation de la consommation de glucides, d’acides gras et de cholestérol liée aux changements des habitudes alimentaires dans la plupart des pays industrialisés est à l’origine de nombreuses pathologies telles que l’obésité, les troubles cardiovasculaires, le développement du diabète de type II et la survenue de cancers. Plusieurs arguments bibliographiques suggèrent notamment que le cholestérol puisse être un élément à risque dans la survenue du cancer de la prostate. D’une part, l’hypercholestérolémie est associée à une augmentation des cas de cancer de la prostate et, d’autre part, les cellules cancéreuses présentent des dérèglements du métabolisme des lipides associés à l’accumulation de cholestérol dans les tumeurs solides. Les objectifs de ces travaux ont été d’analyser le rôle du cholestérol dans le développement du cancer de la prostate et d’étudier le rôle des récepteurs nucléaires LXRs (liver X receptors), régulateurs fondamentaux de l’homéostasie du cholestérol, dans les mécanismes associés à l’initiation et à la progression tumorale. Nos résultats montrent qu’une accumulation de cholestérol, induite par un régime chez les souris déficientes en LXRs, peut initier les premières étapes du développement tumoral par des mécanismes épigénétiques mettant en jeu l’action répressive de l’histone méthyltransférase EZH2 sur des gènes suppresseurs de tumeur. En parallèle, l’activation pharmacologique des LXRs dans des cellules cancéreuses humaines réduit la croissance tumorale en augmentant la mort des cellules par des mécanismes faisant intervenir les rafts lipidiques. Au total, nos travaux révèlent l’existence d’une relation entre la consommation excessive de cholestérol et la modification d’empreintes épigénétiques, mécanisme de plus en plus associé aux processus carcinogéniques. Nos données indiquent également que les LXRs, en s’opposant à l’accumulation de cholestérol intracellulaire, ralentissent l’initiation et la progression du cancer de la prostate. Ainsi, toute stratégie thérapeutique visant à diminuer le cholestérol intra-tumoral, telle que l’activation pharmacologique des LXRs, peut être considérée comme une piste thérapeutique dans le cadre du cancer de la prostate. / In the recent decades, increased consumption of carbohydrates, fatty acids and cholesterol, linked to changes in dietary habits in most industrialized countries, is the cause of various diseases such as obesity, cardio-vascular troubles, development of type II diabetes and the onset of cancer. Literature reveals several arguments suggesting that cholesterol may be a risk factor in the occurrence of prostate cancer. First, hypercholesterolemia has been associated with an increased incidence of prostate cancer and, second, cancer cells exhibit deregulations of lipid metabolism associated with cholesterol accumulation in solid tumors. The objectives of this work were to analyze the role of cholesterol in the development of prostate cancer and to study the role of nuclear receptors LXRs (liver X receptors), fundamental regulators of cholesterol homeostasis, in the mechanisms associated with tumor initiation and progression. Our results show that cholesterol overload induced by a diet in lxr knockout mice may initiate the early stages of tumor development by epigenetic mechanisms involving the repressive action of histone methyltransferase EZH2 on tumor suppressor genes. In parallel, the pharmacological activation of LXRs in human cancer cells reduced tumor growth by increasing cell death through mechanisms involving lipid rafts.Taken together, our data reveal the existence of a relationship between environmental factors such as diet consumption of cholesterol and changes of epigenetic imprinting, a mechanism increasingly associated with carcinogenic process. Our data also indicate that LXRs protect from the initiation and progression of prostate cancer by blocking the accumulation of intracellular cholesterol. Thus, all therapeutic strategies leading to intra-tumoral cholesterol lowering, such as pharmacological activation of LXRs, may be relevant treatments of prostate cancer.

Le cancer de la prostate est le deuxième plus fréquent cancer chez les hommes. La France occupe le troisième rang du taux d’incidence. La curiethérapie bas-débit dose (LDR) est une option de traitement largement utilisée. Au cours de la curiethérapie LDR, des graines radioactives sont implantées en permanence dans la prostate afin de délivrer une dose thérapeutique de façon locale dans la zone cancéreuse tout en épargnant les organes voisins à risque (OAR). Malgré son taux de réussite élevé (75% à 91%), les effets secondaires restent élevés. La dose délivrée à la tumeur dépend des positions d’implantation des graines, ce qui implique que la planification est essentielle. Les systèmes cliniques de planification fournissent automatiquement les positions d’implantation. Cependant, cette prédiction est basée sur un modèle dosimétrique simplifié où le corps humain est considéré comme un volume d’eau. Un autre facteur des erreurs est l’apparition d’un oedème de la prostate impliquant un changement volumétrique. L’oedème peut entraîner une sous-estimation du D90 par exemple il est de 13.6% pour un changement volumétrique de 20%. De plus, l’oedème varie (10% à 96%) entre les patients. Aujourd’hui le mécanisme exact de l’apparition de cet oedème reste inconnu. Nous proposons un système de traitement inverse pour la curiethérapie prostate qui tient compte d’une personnalisation précise de la dosimétrie et de l’oedème. Ces travaux peuvent également être utilisés dans d’autres contextes cliniques, tel que la curiethérapie haut-débit, mais également être adapté pour traiter d’autres organes. Dans le futur, nos travaux porteront sur la personnalisation du modèle biomécanique de la prostate proposé à chaque patient en utilisant des mesures d’élasticité via l’élastographie. En raison des limitations inhérentes à la FEM, l’incorporation du modèle biomécanique de l’oedème dans le système de planification du traitement est coûteuse en temps de calcul. Une méthode alternative, serait de proposer un modèle sans maillage afin d’améliorer la simulation de l’oedème. / Prostate cancer is the second most common cancer in men. Two-thirds of the cases are diagnosed in developed countries and France is ranked third in incidence rate. Low-dose-rate (LDR) brachytherapy is a widely used treatment option. During LDR brachytherapy, radioactive seeds are implanted permanently in the prostate to deliver a therapeutic dose locally in the cancerous region while sparing the organs at risk (OARs). Despite its high success rate (75% to 91%), the side-effects (sexual and urinary problems) remain high. The dose delivered to the tumor depends on the implantation positions of the seeds, which implies that treatment planning is essential. Clinical inverse planning systems automatically provide optimal implantation positions. However, this prediction is based on a simplified dosimetric model where the human body is considered an infinite volume of water. Another important factor that induces treatment errors is the occurrence of prostate edema during brachytherapy that involves volumetric changes of the organ. Edema can lead to a significant underestimation of the D90, for example, by 13.6% for a volumetric change of 20%. Moreover, the edema magnitude varies considerably (10% to 96%) between patients. Today the exact mechanism of edema formation remains unknown. We propose in this thesis a system of inverse treatment for prostate brachytherapy which considers a precise personalization of the dosimetry but also of the prostate edema. This work can also be used in other clinical contexts, such as high-dose-rate brachytherapy, but also be adapted to treat other organs. In the future, our work will focus on the study of the ability to adapt the proposed prostate biomechanical model to each patient using elastic measurements via prostate elastography. Due to the inherent limitations of FEM, the incorporation of the biomechanical model of edema into the treatment planning system is costly in computation time. An alternative method would be to propose a new meshless model to improve the simulation of edema during intraoperative planning.

Orientador: Sebastião RobertoTaboga / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-16T22:39:47Z (GMT). No. of bitstreams: 1 Perez_AnaPauladaSilva_M.pdf: 6001319 bytes, checksum: e128a337509c2f2d797523dafdca8524 (MD5) Previous issue date: 2010 / Resumo: Nos machos, a morfogênese prostática é um evento comandado por andrógenos, que agem diretamente via fatores parácrinos secretados pelo mesênquima. Nas fêmeas, o desenvolvimento embriológico da próstata parece ocorrer em níveis baixos de hormônios esteróides, porém a presença desses hormônios no organismo adulto induz a diferenciação e atividade secretória das células prostáticas. A exposição precoce a estrógeno no período de desenvolvimento embrionário e neonatal tem sido relacionada a distúrbios permanentes na morfofisiologia de vários órgãos do sistema reprodutor de ambos os sexos. Estudos epidemiológicos indicam que homens expostos a componentes estrogênicos durante o desenvolvimento intra-uterino apresentam maior probabilidade de serem inférteis e de desenvolverem câncer de testículo e próstata, enquanto as mulheres tornam-se mais susceptíveis a desenvolver câncer de mama, útero e vagina. Porém, como a exposição precoce a hormônios esteróides é capaz de alterar permanentemente vários órgãos reprodutivos, torna-se questionável se esses agentes também podem interferir com a estrutura e fisiologia da próstata feminina. Com base nesses relatos, o objetivo deste trabalho foi verificar o comportamento da próstata ventral masculina e da próstata feminina de gerbilos adultos que foram expostos ao estrógeno sintético, etinilestradiol durante o desenvolvimento pré-natal, além de analisar a ação pós-natal de andrógenos exógenos sobre ambas as glândulas que foram submetidas à estrogenização do desenvolvimento. Para isso, foram realizadas as análises sorológicas para a quantificação dos hormônios esteróides e as próstatas de gerbilos machos e fêmeas adultos foram submetidas às análises morfológicas, morfométrico-estereológica e imunocitoquímica. Os resultados mostraram que a exposição intra-uterina ao etinilestradiol elevou os níveis séricos de estradiol em ambos os sexos durante a vida adulta, promovendo assim alterações na próstata ventral masculina como neoplasia intra-epitelial prostática (NIP) e irregularidades no epitélio prostático feminino, além de observar o aumento das fibras reticulares e colágenas em ambas as glândulas. A análise imunocitoquímica revelou aumento da imunorreatividade de ?-actina na camada muscular que envolve regiões de lesões prostáticas, e o aumento da imunorreatividade de receptores andrógenos (AR) nas próstatas de ambos os sexos. Os animais que sofreram estrogenização durante o desenvolvimento e mediante aplicação de testosterona na vida pós-natal tiveram os níveis de estradiol normalizado, ainda assim apresentaram lesões prostáticas. Várias dessas alterações são mediadas pelo ER? que foi constatado pela alta imunorreatividade nas próstatas tratadas de ambos os sexos. Com os dados percebeu-se que o tratamento realizado durante o período pré-natal com etinilestradiol promoveu alterações na próstata ventral masculina e na próstata feminina de gerbilos adultos. Porém essas alterações foram mais efetivas na próstata ventral masculina, estando estas associadas aos níveis anormais de estradiol observados nos machos adultos. / Abstract: In males, prostatic morphogenesis is an event controlled by androgens, which act directly via paracrine factors secreted by the mesenchyme. In females, the embryological development of the prostate appears to occur in environment low levels of steroid hormones, but the presence of these hormones in the adult life induces differentiation and secretory activity of prostatic cells. The early exposure to estrogen during the embryonic and neonatal development has been related to disturbances in the permanent morphophysiology of the reproductive system of both sexes. Epidemiological studies indicate that men exposed to estrogenic components during the pre natal development have a higher probability to be infertile and develop and testicular and prostate cancer, while women become more susceptible in developing breast, uterus and vagina cancer. However, as early exposure to steroid hormones can permanently alter various reproductive organs, it is questionable whether these agents can also interfere with the structure and physiology of the female prostate. Based on these reports, the aim of this study was to verify the behavior of gerbil ventral male and female prostates which were exposed to synthetic estrogen ethinylestradiol (EE) during embryonic development, as well as analyze the postnatal action of exogenous androgens on both glands that were submitted to estrogenization. For this were carried out serologic analysis for the measure of steroid hormones and prostate of male and female gerbils adults were subjected to analysis to morphological, morphometric-stereological and immunocytochemical analysis. The results showed that EE intrauterine exposure increased the estradiol serum levels in both sexes, thus promoting alterations in the male prostate such as prostatic intraepithelial neoplasia (PIN) and irregularities in the female prostatic epithelium. Additionally, it was observed an increase of reticular fibers and collagen in both glands. Immunocytochemical analysis revealed increased imunnoreactivity of ?-actin in the muscle layer surrounding regions of prostatic lesions, and increased imunnoreactivity of androgen receptor (AR) in both male and female prostates. The animals that suffered development estrogenization and with the application of testosterone in postnatal life had estradiol levels normalized, still presented prostatic lesions. In addition, in these animals it was verified an increase in the imunnoreactivity of estrogenic receptors (ER?). Several of these alterations are mediated by ER? was verified by high immunoreactivity in prostates treated in both sexes. With the data we noticed that the treatment performed during the prenatal period with ethinyl estradiol promoted alterations in male ventral prostate and female prostate of adult gerbils. But these changes were most effective in the male ventral prostate, these being associated with abnormal levels of estradiol observed in adult males. / Mestrado / Biologia Celular / Mestre em Biologia Celular e Estrutural

Orientador: Ubirajara Ferreira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-06T11:07:31Z (GMT). No. of bitstreams: 1 Silva_ElcioDias_M.pdf: 1742572 bytes, checksum: db8e0fccf7f5b7dd66a71b32ca51cacc (MD5) Previous issue date: 2006 / Resumo: Introdução: margem cirúrgica comprometida ou positiva é definida como tumor estendendo-se na superfície de corte do cirurgião. A porcentagem deste evento, resultante de incisão capsular, varia de 1,3 a 71 % (EPSTEIN, 2001). O objetivo deste estudo é comparar o comprometimento das margens cirúrgicas nas prostatectomias radicais realizadas por via retropúbica e laparoscópica, em dois serviços de referência no Brasil. Pacientes e Métodos: foram analisados os exames anátomo-patológjcos de 179 pacientes submetidos a prostatecomia radical por adenocarcinoma de próstata, 89 por via retropúbica e 90 por via laparoscópica. Critérios de inclusão: pacientes com PSA (antígeno específico da próstata) igual ou menor que 15 ng/ml (nanogramas por mililitro) e Gleason igual ou menor que 7 na biópsia prostática, estádio clínico máximo T2. Resultados: houve comprometimento de margem cirúrgica em 41,57 % dos pacientes submetidos à PRR (prostatectomia radical retropúbica), distribuídos da seguinte maneira: 34,21 % nos estádios pT2 (7,69 % no pT2a, zero no pT2b e 40,98 % no pT2c) e 84,61% nos estádios pT3 (77,77 % no pT3a e 100 % no pT3b). Nos pacientes submetidos a PRL (prostatectomia radical laparoscópica) houve margens cirúrgicas positivas em 24,44 % dos pacientes, distribuídos da seguinte maneira: 20,98 % nos estádios pT2 (11,11 % no pT2a, 27,27 % no pT2b e 21,31 % no pT2c) e 55,55 % nos estádios pT3 (zero % no pT3a e 62,50 % no pT3b). Conclusão: nas amostras analisadas, a proporção de margem cirúrgica positiva foi maior nas prostatectomias radicais realizadas pela via retropúbica do que pela laparoscópica (p= 0,023), em dois serviços de referência nas respectivas técnicas, no Brasil. No entanto, o fato das cirurgias retropúbicas serem realizadas por médicos residentes, em instituição de ensino, e as laparoscópicas realizadas por um único cirurgião experiente, e os exames anátomo-patológicos realizados por técnicas e patologistas distintos, não permite a generalização dos resultados. Maior número de pacientes em estudo prospectivo e randomizado seria necessário para uma melhor comparação entre os grupos / Abstract: Introduction: Compromised or positive surgical margin is defined as a tumor extending at the surgeon cutting surface. A percentage from this event, resulted from capsular incision, varies from 1.3 to 71% (EPSTEIN, 2001). The goal of this study is to compare the compromising of surgical margins at the radical prostatectomies performed through both retropubic and laparoscopic way, in two reference medical services in Brazil. Patients and Methods: pathological examinations were analyzed from 179 patients who underwent to radical prostatectomy by prostate adenocarcinoma, 89 patients by retropubic and 90 patients by laparoscopic way. Inclusion criteria: patients with PSA (prostate specific antigen) equal or less than 15 ng/ml (nanograms by miiiliter) and Gleason score equal or less than 7 at the prostate biopsy, maximum clinical T2 stage. Results: There has been compromising of the surgical margin in 41,57% of the patients who underwent to RRP (radical retropubic prostatectomy), distributed in the following way: 34,21% at pT2 stage (7,69% at pT2a, 0% at pT2b and 40,98% at pT2c) and 84,61% at pT3 (77,77% at pT3a and 100% at pT3b) stage. In the patients who had undergone to LRP (Laparoscopic Radical Prostatectomy), there have been positive surgical margins in 24,44% of the patients as following: 20,98% at pT2 stage (11,11% at pT2a. 27,27% at pT2b and 21,31% at pT2c stage) and 55,55% at pT3 stage (0% at pT3a and 62,50% at pT3b) Conclusion: At the analyzed samples, the proportion of positive surgical margin was greater at the radical prostatectomy performed by retropubic route than by laparocospic one (p=0,023), in two reference medical services using the respective techniques in Brazil. However, the fact that the retropubic surgeries were performed by resident doctors, in teaching school-hospital institution, while the laparoscopic ones were performed by a single expert surgeon and that the pathological examinations were performed by both distinct techniques and pathologists, the result generalization is not allowed. A greater number of patients in a randomized and prospective study would be necessary for a better comparison between the groups / Mestrado / Cirurgia / Mestre em Cirurgia

Orientador: Athanase Billis / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-09T07:48:22Z (GMT). No. of bitstreams: 1 Guimaraes_MarbeleSantos_M.pdf: 9766799 bytes, checksum: 89baad38db3ebd410ea20926179eb1b9 (MD5) Previous issue date: 2007 / Resumo: Há evidências mostrando que a graduação de Gleason para carcinoma da próstata é um dos mais importantes fatores prognósticos de comportamento biológico e um dos mais influentes fatores para determinar o tratamento do câncer da próstata. Este trabalho tem por finalidade comparar: a graduação de Gleason nas biópsias de agulha com a graduação nas prostatectomias radicais correspondentes; correlacionar a graduação de Gleason nas biópsias de agulha com a extensão tumoral nas prostatectomias radicais correspondentes; correlacionar a graduação de Gleason na prostatetomia radical com extensão tumoral, margens cirúrgicas comprometidas e estádio patológico; e, comparar a progressão bioquímica (PSA) da moléstia (recorrência e/ou metástase) pós-prostatectomia radical entre pacientes com: Gleason grau baixo/intermediário (contagem final < 7) vs grau alto (contagem final=7); contagem final 3+4 vs 4+3; e, grau predominante 4 ou 5 vs grau predominante menor que 4. Trata-se de um estudo retrospectivo baseado em 200 espécimes de prostatectomias radicais e de biópsias correspondentes provenientes de pacientes operados no Hospital das Clínicas da FCM-Unicamp no período de 1997 a 2004. A extensão tumoral foi estimada por um método semiquantitativo de contagem de pontos. A progressão bioquímica (recorrência e/ou metástase) da moléstia pós-prostatectomia radical estabelecida pelo Serviço de Urologia do Hospital das Clínicas da Unicamp é o valor de PSA igual ou maior que 0,5 ng/mL. Os dados foram analisados estatisticamente utilizando Statistica 5.5 (StatSoft,Inc., Tulsa, OK, USA). Foi considerado significante o valor de p =0,05. Houve exata correspondência em 47,1% dos casos quando comparada contagem final de Gleason na biópsia de agulha com a contagem final na prostatectomia correspondente. A contagem de Gleason foi subestimada em 40,6% dos casos e superestimada em 12,3% nas biópsias de agulha. A correlação entre contagem final de Gleason nas biópsias de agulha com a extensão tumoral nas prostatectomias radicais correspondentes mostrou-se altamente significante (p<0.001). A correlação da graduação histológica de Gleason na prostatectomia radical foi altamente significante com extensão tumoral (p<0,001), margens cirúrgicas positivas (p<0,001) e estádio patológico (p<0,001). O tempo de recorrência bioquímica (PSA) livre de doença comparando pacientes com Gleason contagem final < 7 vs contagem final >7 (log-rank, p=0,2674); contagem final 3+4 vs 4+3 (log-rank, p=0. 3207); e, grau predominante 4 ou 5 vs grau predominante menor que 4 (log-rank, p=0,1759) não foi estatisticamente significante. Contagens finais maiores na graduação de Gleason na prostatetomia radical se correlacionam com maior extensão tumoral, margens cirúrgicas comprometidas e estádio patológico mais avançado. A maioria dos pacientes mostraram igual ou maior contagem final comparando a contagem final de Gleason na prostatectomia com a biópsia de agulha correspondente. Em nosso estudo, não houve diferença estatisticamente significante em relação à progressão bioquímica quando comparados contagem final <7 vs =7, contagem final 3+4=7 vs 4+3=7 e grau predominante <4 vs =4. predominante 4 ou 5 vs grau predominante menor que 4 (log-rank, p=0,1759) não foi estatisticamente significante / Abstract: There are evidences showing that Gleason grading of prostatic adenocarcinoma is one of the most powerful predictors of biological behavior and one of the most influential factors used to determine treatment for prostate cancer. The aim of the current report was to compare Gleason score on needle biopsy to Gleason score in the correspondent surgical specimen, correlate Gleason score on needle biopsy to tumor extent in surgical specimen, correlate Gleason score in the specimens to several clinicopathologic variables, and compare biochemical (PSA) progression following surgery between patients with Gleason low-grade vs high-grade, Gleason score 3+4 vs 4+3 and Gleason predominant grade <4 or >4. The study population consisted of 200 consecutive patients submitted to radical prostatectomy. Tumor extent was evaluated by a point-count method. Biochemical progression was defined as PSA = 0.5ng/mL. Time to PSA progression was studied using the Kaplan-Meier product-limit analysis. There was exact correspondence in 47.1% of cases, when Gleason score on the biopsy was compared to the correspondent surgical specimen. Gleason score was higher in the specimen in 40.6% of cases and lower in 12.3%. High-grade Gleason score on the biopsy significantly correlated to higher tumor extent (p<0.001). High-grade Gleason score in the surgical specimen significantly correlated to more extensive tumors (p<0.001), positive margins (p<0.001) and extraprostatic extension (pT3a/pT3b) (p<0.001). Time of biochemical (PSA) progression-free survival comparing patients with Gleason score <7 vs =7 (log-rank, p=0.2674), Gleason score 3+4=7 vs 4+3=7 (log-rank, p=0.3207) and Gleason predominant grade <4 vs >4 (log-rank, p=0.1759) was not statistically significant. High-grade Gleason score significantly correlates with more extensive tumors in the surgical specimen, positive margins, and more advanced pathologic staging. Most of the patients show either an exact Gleason score or a higher score in the surgical specimen comparing to the needle biopsy. In our study, time of biochemical (PSA) progression-free survival between patients with Gleason score <7 vs =7, Gleason score 3+4=7 vs 4+3=7 and Gleason predominant grade <4 or >4 was not statistically significant / Mestrado / Anatomia Patologica / Mestre em Ciências Médicas

Submitted by Erika Demachki (erikademachki@gmail.com) on 2017-01-02T16:23:41Z No. of bitstreams: 2 Dissertação - Janaína Ribeiro Costa - 2016.pdf: 3702249 bytes, checksum: c5c72df64f423c647fbe09f7ed58d147 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2017-01-02T16:40:21Z (GMT) No. of bitstreams: 2 Dissertação - Janaína Ribeiro Costa - 2016.pdf: 3702249 bytes, checksum: c5c72df64f423c647fbe09f7ed58d147 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-01-02T16:40:21Z (GMT). No. of bitstreams: 2 Dissertação - Janaína Ribeiro Costa - 2016.pdf: 3702249 bytes, checksum: c5c72df64f423c647fbe09f7ed58d147 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-10-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The prostate is an accessory gland of the mammalian reproductive system with important role in reproduction. The prostatic tissue is regulated by hormones with its homeostasis dependent on a balanced hormonal interaction. The exposure to environmental chemicals with hormonal activities can cause disorders in the prostate increasing the probability of this gland to develop major lesions. Hormonally active chemicals are present in the environment in substantial amounts and forms. Amongst them are the parabens, a class of preservatives with antifungal and antimicrobial activities commonly used in the cosmetic, pharmaceutical and food industry. They are known for affecting the reproductive system and act as endocrine disruptors that mimics the physiological effects of estrogens. Up their, it is unclear whether the exposure to parabens alters the prostate morphophysiology. Therefore, it is relevant to comprehend whether the methylparaben can lead to the development of lesions in the prostate in adult gerbils. Thus, the aim of this work was to evaluate the prostate of adult gerbils exposed to methylparaben. For this, males and females aging 90 days received, through gavage, 500 mg/kg of methylparaben diluted in 1% hydroxyethyl cellulose. These animals were divided into three subgroups that were euthanized after 3 (3P), 7 (7P) and 21 days of treatment (21P). The prostates were collected for structural, cytochemical and immunohistochemical analysis. The results demonstrated that the exposure to methylparaben reduced the body weight of males of 3P and 7P groups, and testis weight of 7P and 21P groups. In the females we observed an increase in the prostatic complex weight of the 21P group. In both sexes, Gömöri’s reticulin staining showed a remodeling of the stromal compartment with reticular fibers disorganization and collagen fibers increase. Besides, males and females presented important morphological alterations as hyperplasic growth foci. In females, it was observed the presence of prostatic intraepithelial neoplasia, stromal inflammatory foci and an increase of ERα-positive cells. Immunohistochemical data showed an increase of ARpositive cells and in the proliferation rates for both genders. Altogether, these data demonstrate that methylparaben was capable to interfere in androgenic and estrogenic receptors, suggesting that this chemical might have estrogenic and anti-androgenic activity in the prostate. In males there was an intense immunostaining for MGMT in all treated groups whereas in females only in the 3P group. The immunostaining for MGMT in the prostate of males and females suggests that the exposure to methylparaben made the gland more susceptible to epigenetic modifications. The results obtained with this study are alarming, as they indicate that the increasing consumption of parabens by urban population can be related with the arising of morphophysiological alterations in prostate. / A próstata é uma glândula acessória do aparelho reprodutor dos mamíferos e tem importante função na reprodução. O tecido prostático é regulado por hormônios esteroides, sendo que sua homeostase depende de uma interação hormonal equilibrada. A exposição a químicos ambientais que apresentam atividade hormonal pode ocasionar distúrbios na próstata, aumentando a probabilidade dessa glândula desenvolver lesões. Compostos químicos hormonalmente ativos estão presentes em grande quantidade e de diversas formas no meio ambiente. Dentre estas substâncias estão os parabenos, uma classe de conservantes com ação antimicrobiana e antifúngica amplamente utilizada na indústria cosmética, farmacêutica e alimentícia. Os parabenos são conhecidos por perturbar o sistema reprodutivo e agir como desreguladores endócrinos que mimetizam os efeitos fisiológicos dos estrógenos. Até o momento, não está claro se os parabenos podem alterar a morfofisiologia da próstata. Portanto, é relevante entender se o metilparabeno pode predispor a próstata a desenvolver lesões na idade adulta. Assim, o objetivo desse trabalho foi avaliar a próstata de gerbilos adultos expostos ao metilparabeno. Para isto, machos e fêmeas com 90 dias de idade receberam, por gavagem, 500 mg/kg de metilparabeno diluídos em hidroxietil-celulose a 1%. Estes animais foram divididos em três subgrupos que foram sacrificados após 3, 7 e 21 dias de tratamento. As próstatas foram coletadas para análises estruturais, citoquímicas e imunohistoquímicas. Os resultados monstraram que a exposição ao metilparabeno diminuiu o peso dos testículos dos grupos 7 e 21 dias. Nas fêmeas houve aumento do peso do complexo prostático do grupo de 21 dias. Em ambos os sexos, a Reticulina de Gömöri mostrou um remodelamento do compartimento estromal com desorganização das fibras reticulares e aumento das fibras colágenas. Além disso, machos e fêmeas apresentaram alterações morfológicas importantes como focos de crescimento hiperplásico do epitélio secretor. Nas fêmeas observou-se a presença de neoplasia intraepitelial prostática, focos inflamatórios estromais, e aumento de células ERα- positivas. Houve um aumento do número de células AR-positivas, e aumento das taxas de proliferação celular em ambos os sexos. Em conjunto, estes dados indicam que o metilparabeno foi capaz de interferir com receptores androgênicos e estrogênicos, sugerindo que este químico pode ter atividade estrogênica e antiandrogênica na próstata. Nos machos houve uma intensa imunomarcação para MGMT (O6-Metilguanina-DNAMetiltransferase) em todos os grupos tratados e nas fêmeas apenas no grupo 3P. A imunomarcação para MGMT na próstata masculina e feminina sugere que a exposição ao metilparabeno tornou a glândula mais suscetível a modificações epigenéticas. Os resultados obtidos com este estudo são relevantes, pois demonstram que o consumo crescente de parabenos pelas populações humanas pode estar relacionado com o surgimento de alterações morfofisiológicas da próstata.

INTRODUÇÃO: O diagnóstico do câncer de próstata em pacientes com níveis séricos do antígeno prostático específico persistentemente elevados após biópsia prostática negativa representa um grande desafio para urologistas e patologistas. A baixa especificidade do antígeno prostático específico e a baixa sensibilidade da biópsia prostática guiada por ultra-som são os maiores obstáculos observados na prática clínica. Apesar do uso de diversos métodos para prever a presença de câncer na glândula, nenhum deles tem precisão absoluta, obrigando os pacientes a realizar novas biópsias. Neste contexto, a descoberta de novos marcadores diagnósticos para o câncer da próstata tornase necessária. OBJETIVO: Avaliar o valor diagnóstico da expressão de seis genes no tecido prostático de pacientes com câncer de próstata clinicamente localizado. MÉTODOS: O estudo consistiu na análise de 50 pacientes com diagnóstico de câncer da próstata, submetidos à prostatectomia radical por doença localizada. A seleção dos genes foi baseada em um estudo prévio que utilizou a tecnologia de microarray (Agilent Technologies 44k whole human genome, two-color) em pacientes com câncer de próstata, divididos de acordo com as características clínico-patológicas. Entre os 4.147 genes com expressão diferenciada entre os casos de câncer de próstata, seis genes (PSMA, TMEFF2, GREB1, TH1L, IgH3 e PGC) foram selecionados. Estes genes foram então testados quanto a seu valor diagnóstico no câncer da próstata através da técnica de reação em cadeia da polimerase quantitativa com transcriptase reversa. Na primeira etapa do estudo, amostras de tecido maligno de 33 pacientes com câncer de próstata foram avaliadas. O grupo controle foi composto de nove pacientes com hiperplasia benigna da próstata. Na segunda etapa do estudo foram analisadas amostras de tecido benigno dos demais 17 pacientes com câncer da próstata. O mesmo grupo controle foi utilizado para comparação. RESULTADOS: A análise demonstrou que o PSMA estava super-expresso (em média nove vezes) e o PGC sub-expresso (em média de 1,3 x 10-4 vezes) no tecido neoplásico de todos os casos de câncer quando comparados com os casos de hiperplasia benigna. Os demais genes demonstraram um padrão de expressão variado, não permitindo a diferenciação entre os tecidos malignos e benignos. Quando estes resultados foram testados no tecido prostático benigno dos pacientes com câncer, o PGC manteve o mesmo padrão de expressão em todos os casos e o PSMA, apresentou-se super-expresso em 88% dos pacientes (média de 12 vezes), em relação aos casos de hiperplasia benigna. CONCLUSÃO: A combinação da super-expressão do PSMA e sub-expressão do PGC no tecido prostático pode representar uma evidência objetiva de presença de Cap. Análises clínicas prospectivas adicionais são necessárias para confirmar estes resultados / Introduction and objective: Prostate cancer (PCa) diagnosis in men with persistently increased PSA after a negative initial prostate biopsy has become a great challenge for urologists and pathologists. Despite the use of several methods to increase the sensitivity of prostate biopsy, the false-negative rates remain substantial, leading many patients to undergo repeated procedures. We analyzed the diagnostic value of six genes in the prostatic tissue of patients with clinically localized PCa, in order to predict the presence of cancer. Methods: The study was comprised by 50 patients with clinically localized PCa who underwent radical prostatectomy. Gene selection was based on a microarray analysis of patients with PCa. Among the 4,147 genes with different expressions between two groups, six genes (PSMA, TMEFF2, GREB1, TH1L, IgH3 and PGC) were selected. These genes were tested for its cancer diagnostic role using the quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) method. In the first part of the study, malignant tissue samples from 33 patients were analyzed, and in the second part we analyzed benign tissue samples of the other 17 patients with PCa. The control group was comprised of prostatic tissue samples of patients with benign prostatic hyperplasia (BPH). Results: The analysis of malignant prostatic tissue by qRTPCR showed that PSMA was over-expressed (mean nine times) and PGC was under-expressed (mean 1.3 x 10-4 times) in all cases when compared to BPH. The other four tested genes showed a variable expression pattern not allowing a differentiation between benign and malignant cases. When we tested these results in the benign prostate tissues from patients with PCa, PGC maintained the expression pattern, and PSMA, despite over-expression in most cases (mean 12 times), two cases (12%) presented under-expression. Conclusions: PGC under-expression and PSMA over-expression in the tissue may represent an objective evidence of prostate cancer and constitute a powerful adjunctive method in patients with negative prostate biopsy. Further prospective clinical analyses are necessary to confirm theses results

The field of systems biology has become very popular as a means to deal with cancer as well as other complex biological issues. It enables scientists to gain an insight into difficult conditions through mathematical approaches that have been developed. Prostate cancer is the second leading cause of death among men after skin cancer and its heterogeneity makes it a complex disease. In this study we focus on three pathways known to play crucial roles in the formation of prostate cancer. By using a mathematical model that combines all of them we describe the interactions taking place during signal transduction in the prostate under normal and cancer conditions.

Suite à l’émergence de protocoles d’hypofractionnement à visée curative comportant un risque accru de toxicité, il devient fondamental d’arriver à augmenter la précision dans la délivrance de la dose. Les mouvements internes entre et pendant les séances d’irradiation peuvent devenir un facteur limitant majeur pour la qualité de l’irradiation des localisations tumorales mobiles. C’est le cas pour le cancer de la prostate pour lequel l’hypofractionnement est une voie prometteuse bien qu’il existe un risque élevé de toxicité digestive. Lors de cette thèse, nous nous sommes intéressés à la quantification et correction des mouvements du volume cible irradié dans le cadre d’une radiothérapie pour un cancer de la prostate sans ou après ablation totale de la glande. Nous avons étudié un nouveau système d’imagerie basé sur la modalité ultrasons (US) permettant de visualiser la zone pelvienne grâce à deux voies d’acquisition : transabdominale (TA) et transpérinéale (TP). Contrairement aux systèmes US précédemment commercialisés, les mouvements entre les séances de simulation et de traitement (mouvements interfractions) sont quantifiés par recalage monomodal US/US. De plus, des images acquises avec la sonde TP en continu pendant l’irradiation permettent de quantifier les mouvements intrafractions du volume cible. Nous avons proposé une méthodologie d’évaluation des deux sondes US-TA et US-TP pour la correction des mouvements interfractions, en conditions cliniques. Les données US ont été comparées à celles obtenues par tomodensitométrie (CBCT), actuelle modalité de référence. De plus, nous avons quantifié pour la première fois les incertitudes liées à l’impact de la pression de la sonde sur la localisation du volume cible, et à la variabilité inter-opérateur du recalage manuel US/US. Nous avons observé pour la sonde TA une faible concordance entre les mouvements interfractions mesurés par US et CBCT, ainsi qu’une variabilité importante de la pression exercée par la sonde et du recalage manuel entre les opérateurs. Pour la sonde TP, nous avons proposé une méthode corrective de la localisation de l’image US de référence qui nous a permis de valider son utilisation en clinique. Les données recueillies avec la sonde TP ont montré une importante variation des amplitudes et fréquences des mouvements intrafractions, parfois supérieurs à 15mm, entre les patients et d’une séance à l’autre pour un même patient. Nous avons proposé une étude dosimétrique des conséquences de ces déplacements et ainsi démontré que l’impact sur la dose délivrée au volume cible est patient-dépendant, et est plus important lorsque le traitement est délivré avec une stratégie d’hypofractionnement. Nous avons démontré dans cette étude la faisabilité de l'implémentation clinique de la technique US-TP qui permet un repositionnement quotidien en début de séance sans dose additionnelle ou marqueurs invasifs, et la correction de la position du volume cible pendant l’irradiation. / The emergence of hypofractionated treatments implies an increase of precision on the dose delivery. Organs motions between and during the irradiation fraction are a limiting factor for achieving a high quality treatment of mobile tumor localizations. In particular, hypofractionation was demonstrated as a promising strategy for prostate cancer treatment, whereas a high digestive toxicity cannot be excluded.During this thesis, motions of the target volume were quantified during radiotherapy delivered for treating a prostate cancer, on the prostatic gland or after a prostatectomy. An innovative imaging modality was used, based on two different ultrasound (US) probes: a transabdominal (TA) probe and a transperineal (TP) probe. Contrary to US systems previously commercialized, motions between simulation and treatment sessions were quantified with a monomodal registration US/US. Moreover, intrafraction motions of the target volume were recorded with the TP probe, since images can be continuously acquired with this probe. A methodology for evaluating the performances of the TA and TP probes were developed for the correction of interfractions motions, in clinical conditions. US data were compared with the current reference modality, the Cone Beam Computed Tomography (CBCT). Moreover, the uncertainties on the target localization due to the variability of the probe pressure and to inter-operator variability of the manual US/US registration were quantified for the first time. Poor agreements of the interfraction motions measurements were found between US and CBCT modalities, using the TA probe. Furthermore, a high variability of the TA probe pressure and of the inter-operator registration was observed. Using the TP probe, a corrective method of the US reference image localization was developed and validated, leading to a high agreement with the CBCT modality.Intrafraction motions were observed with the TP probe, and were highly patient and session dependent. A dosimetric study was proposed to evaluate the impact of the intrafraction motion on the dose delivery. The effects were patient dependent and more important when the treatment was simulated using a hypofractionated strategy.

Le cancer de la prostate est le cancer le plus fréquemment diagnostiqué chez l’homme de plus de 50 ans dans les pays industrialisés. L’importance accordée à la qualité de vie des patients conduit la recherche médicale à développer des méthodes de thérapie focale afin de traiter ce type de cancer de manière conservatrice et non plus de manière radicale. Dans cette optique, la photothérapie dynamique (PDT) repose sur l’utilisation de photosensibilisateurs (PS) capables de cibler spécifiquement les cellules cancéreuses et qui, une fois activés par la lumière, vont induire la mort de ces cellules. Sur la base de la chimie verte, le Laboratoire de Chimie des Substances Naturelles (LCSN) de Limoges a développé une stratégie de couplage de la protoporphyrine IX (PpIX), un PS largement étudié, avec des polyamines (PA). Les effets de ces nouveaux PS [la protoporphyrine IX dispermidinée (PpIX-dSd) et la protoporphyrine IX disperminée (PpIX-dSm)] ont été étudiés sur les cellules cancéreuses prostatiques humaines PC-3, DU 145 et LNCaP. Ce travail a permis de démontrer que ces deux PS répondent aux critères attendus d’un PS : une composition pure, une absence de toxicité en absence de lumière et une sélectivité vis-à-vis des cellules tumorales. De plus, ces PS induisent l’apoptose de ces cellules via la voie intrinsèque. Aussi les voies de résistance à l’apoptose ont été étudiées : les PS induisent une inhibition d’Akt, de Bcl-2, de NF-κB et de la voie autophagique et activent la voie p38/COX-2/PGE2 qui ne semble pas être impliquée dans un mécanisme de résistance à l’apoptose dans ce modèle d’étude. Enfin, l’efficacité de ces PS, et notamment de la PpIX-dSd, a été mise en évidence in vivo, à l’aide de xénogreffes sous-cutanées de cellules PC-3 effectuées sur des souris nudes. Ainsi, ces dérivés de PpIX-PA apparaissent comme de bons candidats dans le cadre du traitement du cancer de la prostate par PDT. / Prostate cancer is the most frequently diagnosed cancer among men aged 50 years and older in industrialized countries. Medical research developed methods of focal therapy to treat this type of cancer conservatively and not radically in order to improve the patients quality of life. With this in mind, photodynamic therapy (PDT) is based on the use of photosensitizers (PS) able to specifically target cancer cells and, once activated by light, induce cell death. Based on Green Chemistry, the Laboratoire de Chimie des Substances Naturelles (LCSN) from Limoges developed new PS: protoporphyrin IX, a PS widely studied, vectorized with polyamines (PA). The effects of spermidine-linked protoporphyrin IX (PpIX-dSd) and spermine-linked protoporphyrin IX (PpIX-dSm) were studied on human prostate cancer cells PC-3, DU145 and LNCaP. This study demonstrated that both PS have the expected ideal properties: a pure composition, no toxicity in dark and ability to specifically target tumor cells. Moreover, PpIX-PA induced apoptotic intrinsic pathway. In addition, pathways involved in apoptosis resistance were studied: PS inhibited Bcl-2, Akt, NF-¦ÊB and autophagy but activated p38/COX-2/PGE2 pathway which was not involved in apoptosis resistance in our model. Finally, in vivo experiments showed PpIX-PA efficiency using subcutaneous xenograft of PC-3 cells performed on nude mice. Thus, these derivatives of PpIX-PA appear to be good candidates in prostate cancer treatment by PDT.