Experimental carcinogenesis in the ventral Mongolian s gerbil prostate / Carcinogenese experimental no lobulo ventral da prostata do geribo da Mongolia

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

The prostate cancer is the most common tumor that attacks men from the 50 s decade. Among the risk factors that contribute to this disease s increase stand out the aging process, when hormonal unbalances happen frequendy. Developmental studies of prostatic tumors have been complicated because of difficult in obtaining human material, once this question lies on medical ethics. Researchers group have had tried to develop, characterize and validate some rodent models to analyze the prostate cancer. Autoctone models used to study spontaneous prostatic lesions have performed important role to these kind of neoplasia. ln addition, lots of innstigations have been done about experimental induction of prostatic tumors in rats, mice and guinea pig. ln a first phase of the present work, it was realized in the ventral lobe of old gerbil s prostate veriones unguiculatllm) structural and ultra-structural morphological, quantitative and functional analyzes of the cellular compounds of epithelial and stromal compartments. The prostatic features of theses animaIs revealed that in a same gland could be noted functional regions containing normal secretof) epithelium and regions completely altered, showing histopathological lesions. A testosterone concentration decrease associated to these prolifera tive sites confmns the importam role of this androgen to the prostatic homeostasis. Because of these data, in the second phase of this. work, it was done a prostatic tumors experimental induction in the adult gerbil, after conjugate treatment of N-metil-N-nitrosourea with testosterone propionate. Once the tumors were established, prostate fragments were processed for histological, immunocytocl)emical and ultra-structural studies. The results showed that in gerbils, the emergence of prostatic lesions happened in experimental periods of until 9 months and both the carcinogen and testosterone, associated or not, was able to induce these adenocarcinomas. The invase potencial of anomalus cells could be proved by ultra-structural analyz~s and by the immunocytochemical test for laminima, noted in the basal membrane disruption. On the other hand, it was observed that gerbil is one of the pioneers in expression of the citoplasmatic protein Alfa-lvletilacilCoARacemase (P504S), which is found in the neoplastic cells, likely in prostatic human cancer. Concluding, this study is pioneer in the demonstration of the P504S expression in rodents. Based on these presented data, it was verified that gerbil is a good experimental model to chemical carcinogenesis research of the prostate, which taken together with previous literature will give a better and profounder understanding of prostatic lesions.

ASSUNTO(S)

gerbil alfa-metilacil-coa-racemase prostata n-metil-n-nitrusoureia n-methyl-n-nitrusourea alpha-methylacil-coa-racemase prostate lesões proliferativas gerbillinae profilative lesions

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