siRNA-mediated silencing of Notch-1 enhances docetaxel induced mitotic arrest and apoptosis in prostate cancer cells

Purpose: Notch is an important signaling pathway that regulates cell fate, stem cell maintenance and theinitiation of differentiation in many tissues. It has been reported that activation of Notch-1 contributes totumorigenesis. However, whether Notch signaling might have a role in chemoresistance of prostate cancer isunclear. This study aimed to investigate the effects of Notch-1 silencing on the sensitivity of prostate cancercells to docetaxel treatment. Methods: siRNA against Notch-1 was transfected into PC-3 prostate cancer cells.Proliferation, apoptosis and cell cycle distribution were examined in the presence or absence of docetaxel byMTT and flow cytometry. Expression of p21waf1/cip1 and Akt as well as activation of Akt in PC-3 cells were detectedby Western blot and Real-time PCR. Results: Silencing of Notch-1 promoted docetaxel induced cell growthinhibition, apoptosis and cell cycle arrest in PC-3 cells. In addition, these effects were associated with increasedp21waf1/cip1 expression and decreased Akt expression and activation in PC-3 cells. Conclusion: Notch-1 promoteschemoresistance of prostate cancer and could be a potential therapeutic target.