A leptina regula a proliferação celular e a apoptose na próstata humana

Abstract

The benign prostate hyperplasia (BPH) is the disease in which the prostate shows an abnormal growth and its prevalence rise up with aging. Leptin, the most well characterized adipokine, has an important role regulating the reproductive system. This paper aimed to evaluate the leptin role in the human prostate tissue, using an in vitro tissue culture system, on the cellular proliferation and the expression of fibroblast growth factor 2, aromatase enzyme and apoptotic genes. From 2009 to 2011, hyperplasic prostate tissue samples obtained by transvesical prostatectomy in fifteen patients with enlarged prostates were used. Each sample was divided in four symmetric parts which were maintained in RPMI medium supplemented with 10% fetal bovine serum, 1 ng/mL of gentamicin and added with 16 ng/mL leptin (L) or not (C). After 3 hours gene expression of FGF2, aromatase, Bax, Bcl-x and Bcl-2 were evaluated by Real Time RT-PCR. Cellular proliferation was evaluated by imunohistochemistry for PCNA. The leptin treatment led to an increase in the expression of Bax (C=0.4±0.1; L=0.9±0.2; p<0.05) while Bcl-2 (C=19.9±5.6; L=5.6±1.8; p< 0.05) and Bcl-x (C=0.2±0.06; L=0.07±0.02; p<0.05) expressions were significantly reduced. There was no significant alteration in the FGF2 expression, while the aromatase expression was significantly (C=1.9±0.6; L=0.4±0.1; p<0.04) reduced. Leptin also resulted in an increase in cellular proliferation (C=21.8±0.5; L=64.8±0.9; p<0.0001). The conclusion is that leptin has an important role in maintaining the physiological growth of the prostate since it stimulates both cellular proliferation and apoptosis, with the decrement in the aromatase gene expression