EXPRESSION OF GONADOTROPIN-RELEASING-HORMONE (GNRH) AND GNRH RECEPTORMESSENGER-RNA IN PROSTATE-CANCER CELLS AND EFFECT OF GNRH ON THE PROLIFERATION OF PROSTATE-CANCER CELLS

The purpose of this study was to determine the production of gonadotro pin-releasing hormone (GnRH), the co-occurrence of GnRH receptors in p rostate cancer cells, and the effect of GnRH on prostate cancer cell p roliferation. Four human prostate cancer cell lines were studied. LNCa P is an androgen sensitive prostate cancer cell line, DU-145 and PC-3 are androgen resistant, and TSU-Prl is uncharacterized. The expression of GnRH and GnRH receptor mRNAs were assessed by in situ hybridizatio n and the effect of exogenous GnRH on proliferation of prostate cancer cells was measured by thymidine incorporation assay. GnRH mRNA expres sion, determined by in situ hybridization, was found in 83.48% of the LNCaP, 89.7% of the TSU-Pr1, 86.2% of the PC-3 and 95.3% of the DU-145 . Signals of GnRH receptor mRNA were detected in more than 95% of the cells of all four cell lines. The proliferation of the prostate cancer cells grown in media supplemented with peptide hormone lacking charco al-stripped serum was significantly (P < 0.05) suppressed. No signific ant effect of GnRH on the proliferation of all four prostate cancer ce lls was observed. In summary, prostate cancer cells produced GnRH and its receptors, and exogenous GnRH treatment did not affect the prostat e cancer cell proliferation. The existence of GnRH and GnRH receptor m RNA in the same cell suggests that the role of GnRH produced by prosta te cancer cells would be autocrine.