Master of Science / Department of Human Nutrition / Brian Lindshield / 5α-reductase 1 (5αR1) and 5α-reductase 2 (5αR2) convert testosterone into the more potent androgen, dihydrotestosterone (DHT), that is responsible for regulating prostate growth and proliferation. 5αR2 is the main isoenzyme in normal prostate tissue, however prostate tumors have increased 5αR1 and decreased or unchanged 5αR2 expression. Previously, finasteride (5αR2 inhibitor) treatment begun 3 weeks after tumor implantation had no effect on Dunning R3327-H rat prostate tumor growth. We believe the tumor compensated for finasteride treatment by increasing tumor 5αR1 activity to produce dihydrotestosterone to stimulate its growth. We hypothesize that finasteride treatment would not significantly alter tumor growth even if begun before tumor implantation, while dutasteride (dual 5αR1 & 5αR2 inhibitor) treatment would decrease tumor growth regardless if treatment is begun before or after tumor implantation. Sixty, 8-week old male nude mice were randomized to Control, Pre-Finasteride, Post-Finasteride, Pre-Dutasteride and Post-Dutasteride diet groups (all diets contained 83.3 mg drug/kg diet). Pre groups began their treatment diets 1-2 weeks prior to tumor implantation, while post groups began their treatment diets 3 weeks after tumor implantation. Tumors were implanted by subcutaneous injection of 1 x 10⁵ WPE1-NA22 human prostate cancer cells in Matrigel™ and allowed to grow for 22 weeks. Tumor areas, body weights, and feed intakes were measured weekly. At study conclusion, prostate and seminal vesicle weights were significantly decreased in all treatment groups versus the control. Dutasteride intake also significantly reduced seminal vesicle weights compared to finasteride intake. There were no significant differences in final tumor areas or tumor weights between groups, likely due to poor tumor growth. In follow-up studies, proliferation of WPE1-NA22 prostate cancer cells, and its parent line RWPE-1 prostate epithelial cells, were unaltered by treatment with testosterone, DHT, or the synthetic androgen mibolerone, suggesting that these cell lines are not androgen-sensitive. Thus, the lack of response to androgen treatment by WPE1-NA22 prostate cancer cells may explain the inadequate tumor growth observed.

Orientadores: Wagner Eduardo Matheus, Ubirajara Ferreira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-24T09:15:24Z (GMT). No. of bitstreams: 1 Alonso_JoaoCarlosCardoso_M.pdf: 3539592 bytes, checksum: 0be37d55627566f90e50845617162ed4 (MD5) Previous issue date: 2013 / Resumo: Introdução: Os andrógenos, além de desempenhar um papel importante no desenvolvimento e no crescimento da próstata, também são responsáveis pelo surgimento e progressão de lesões prostáticas. Portanto, as ações desses hormônios podem ser antagonizadas impedindo a conversão irreversível de testosterona em dihidrotestosterona, por meio da inibição da 5?-redutase. Neste contexto, os objetivos deste estudo foram caracterizar os efeitos clínicos e morfofuncionais da dutasterida, um inibidor de 5?-redutase, em receptores de hormônios esteroides no tecido da próstata humana normal, bem como para verificar a viabilidade desses receptores como potenciais marcadores para o manejo clínico dos pacientes em uso de dutasterida. Métodos: estudo prospectivo, duplo-cego e randomizado que avaliou 49 homens com idades entre 45 e 70 anos, sem alterações no exame de toque retal e com dosagens de PSA entre 2,5 e 4,0 ng/ml. Estes pacientes foram submetidos a biópsia de próstata guiada pelo ultrassom transretal, e após ter sido descartada neoplasia de próstata, foram divididos em dois grupos recebendo dutasterida (n=25) ou placebo (n=24). Os pacientes foram avaliados clinicamente a cada trimestre e, ao final de 12 meses, submetidos a novos testes laboratoriais e análise histopatológica por nova biópsia da próstata. Resultados: Os resultados não mostraram variações significativas nos níveis de estrógeno, testosterona séricos e índice de massa corporal em ambos os grupos, bem como de ER? (receptor estrogênico ?). No entanto, a imunorreatividade para AR (receptor androgênico) e ER? (receptor estrogênico ?) foram significativamente maiores no grupo dutasterida em relação ao grupo placebo, acompanhado por uma redução significativa do volume da próstata e dos níveis de PSA séricos no grupo dutasterida. Além disso, ambos os índices de proliferação e apoptose também foram significativamente maiores no grupo dutasterida, porém a razão proliferação/apoptose foi significativamente menor neste grupo, indicando assim predominância de apoptose. Conclusão: O tratamento com dutasterida mostrou distintas reatividades no tecido prostático normal, apontando a importância da ativação de ER? no mecanismo apoptótico, propiciando efeito protetor no tecido prostático normal, indicando ser este receptor um importante mediador para o seguimento clínico de pacientes em uso de dutasterida / Abstract: Introduction: The androgens, besides playing an important role in prostate development and growth, are also responsible for the development and progression of prostatic lesions. Therefore, preventing the irreversible conversion of testosterone into dihydrotestosterone by inhibiting 5?-redutase can antagonize the actions of these hormones. In this context, the aims of this study were to characterize the clinical and morphofunctional effects of 5?-redutase inhibitor, dutasteride, on steroid hormone receptors in the human normal prostate tissue, as well as to verify the viability of these receptors as potential markers to clinical management of patients on dutasteride use. Methods: Prospective, randomized and double-blind study, evaluating 49 men with ages between 45 and 70 years, no alterations in digital rectal examination and PSA levels between 2.5 and 4.0 ng/ml. These patients underwent prostate biopsy guided by transretal ultrasound (TRUS) with prostate neoplasia ruled out and it has divided into two groups receiving dutasteride (n=25) or placebo (n=24). Patients were clinically assessed every three months and at the end of 12 months undergoing new laboratory tests, prostate rebiopsy, histopathological and clinical analysis. Results: The results did not show significanty variations in serum estrogen and testosterone levels and body mass index in both dutasteride and placebo groups, as well as their ER? (? estrogen receptor). However, AR (androgen receptor) and ER? (? estrogen receptor) immunoreactivity were significantly higher in the dutasteride group in relation to placebo group, followed by a significant reduction in prostate volume performed by TRUS and total serum PSA levels in the dutasteride group when compared to placebo group. Furthermore, both proliferative and apoptotic indices were significantly higher in the dutasteride group in relation to placebo group. However, the proliferation/apoptotic ratio was significantly lower in the dutasteride group, indicating predominance of apoptotic process. Conclusion: The dutasteride treatment led to distinct reactivities in the normal prostate tissue, indicating different signals to the dynamics of the prostate and pointed out the importance of ER? pathways in the activation of apoptosis. Taken together, these data demonstrated that dutasteride treatment exerted protective effect in the normal prostate via ER?, indicating this receptor as important mediator to clinical management of patients on dutasteride use / Mestrado / Fisiopatologia Cirúrgica / Mestre em Ciências

Doctor of Philosophy / Department of Human Nutrition / Brian L. Lindshield / The growth-inhibitory effect of saw palmetto supplements (SPS) with high long-chain fatty acids (FA)-low phytosterols (HLLP), high long-chain FA-high phytosterols (HLHP), and high medium-chain FA-low phytosterols (HMLP) was determined using androgen-sensitive LNCaP prostate cancer (PCa) cells and Syrian hamster flank organs. In vitro, all three SPS at high concentrations significantly decreased dihydrotestosterone-stimulated LNCaP cell number. HMLP and HLLP at high concentrations significantly decreased, but HLHP which significantly increased testosterone-stimulated LNCaP cell number. In Syrian hamsters, all three SPS treatments caused notable, but nonsignificant reduction in the difference between the left and right flank organ growth in the testosterone-, but not dihydrotestosterone-treated SPS groups. Results suggest SPS might be a mild 5-alpha-reductase (5-alpha-R) inhibitor. The pharmaceuticals finasteride inhibits 5-alpha-R2, and dutasteride inhibits 5-alpha-R1 and 5-alpha-R2 isoenzymes. Because finasteride inhibits only 5-alpha-R2, we hypothesized that it would not be as efficacious in preventing PCa development and/or progression in TRAMP mice as dutasteride. Six-week-old C57BL/6 TRAMP x FVB male mice were randomized to control, pre- and post- finasteride and dutasteride diet groups that began at 6 and 12 weeks of age, respectively, and terminated at 20 weeks of age. Pre and post groups received drugs before and after mice were expected to develop PCa, respectively. Post-Dutasteride treatment was significantly more effective than Pre-Dutasteride; and dutasteride treatments significantly more effective than finasteride treatments in decreasing prostatic intraepithelial neoplasia progression and PCa development. The finasteride groups and the Pre-Dutasteride group had significantly increased incidence of poorly differentiated PCa versus control. Androgen receptor and Ki-67 protein, DNA fragmentation from apoptosis, 5-alpha-R1 and 5-alpha-R2 mRNA levels were determined in mice with genitourinary weight less than 1 gram and greater than 1 gram to elucidate the discordant response in Pre-Dutasteride and finasteride groups, and Post-Dutasteride’s efficacy. Results suggest the difference in genitourinary weights is influenced more by proliferation, rather than androgen receptor and apoptosis in tumor. Mice age may not be significantly important in regulating proliferation, androgen receptor and apoptosis to promote tumor growth. In conclusion, the results with 5-alpha-reductase inhibitors may support the therapeutic use of dutasteride, but not finasteride, or saw palmetto supplements.