Prostatic microenvironment in senescence: fibroblastic growth factors × hormonal imbalance

The aim was to characterize and correlate steroid hormone receptors with the FGF2, FGF7 and FGF8 reactivities in the prostatic epithelium and stroma in senile rats. Fifty male senile rats and 10 young male rats were divided into the young (YNG), the senile groups (SE), the castrated group (CAS), the estrogen-deficient group (ED), the castrated + estrogen group (CASE), and the estrogen-deficient + androgen group (EDTEST). The ventral prostate was submitted to immunohistochemical and Western blotting analyses. The results showed decreased AR and ERβ levels and increased ERα in the senile animals in relation to YNG group. Increased ERα and ERβ reactivities presenting differential localization were characterized in the CASE group compared to the CAS group. Increased FGF2 level was observed in the stroma of the CAS and ED groups in relation to the SE group and in the epithelium of the ED group in relation to the other groups. Increased and differential immunolocalization of FGF7 levels were observed in the CAS, ED and CASE groups. The FGF8 levels showed differential localization in the CAS and ED groups compared to the senile group. The intense hormone ablation was favorable to the autocrine signaling of FGF2 and FGF8. FGF7 could be activated in the androgen-independent via considering the increased FGF7 in the castrated rats. We concluded that hormone ablation in senescence was favorable to activation or/and to fibroblast signaling in the prostatic microenvironment.