Effect of withdrawal of androgen on expression of anti-apoptotic protein Bcl-2 and Bcl-X_L in human prostate carcinoma cells

Objective: To study the effect of withdrawal of androgen on expression of anti apoptotic protein Bcl 2 and Bcl X L in human prostate carcinoma cells. Methods: Expression of Bcl 2 and Bcl X L in human androgen dependent prostate carcinoma cell line LNCaP was measured by using Western blot analysis after withdrawal of androgen. Human androgen independent prostate carcinoma cell line PC 3 was also examined as control. Results: Down regulation of Bcl X L was detected in LNCaP cell line 10 h after withdrawal of androgen and the lowest expression level of Bcl X L was found after 24 h. Up regulation of Bcl 2 was found in LNCaP cell line after 12 h of withdrawal of androgen, and reached the highest after 24 h. No change of expression of either Bcl 2 or Bcl X L was found in PC 3 cell line after withdrawal of androgen. Conclusion: Withdrawal of androgen can down regulate the expression of Bcl X L, which may be one of the mechanisms by which prostate carcinoma can be controlled after androgen ablation by either operative or medicine methods. Expression increase of Bcl 2 may be one of the mechanisms by which androgen independent PCa is developing.