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 the initiation of differentiation in many tissues. It has been reported that activation of Notch-1 contributes to tumorigenesis. However, whether Notch signaling might have a role in chemoresistance of prostate cancer is unclear. This study aimed to investigate the effects of Notch-1 silencing on the sensitivity of prostate cancer cells 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 by MTT and flow cytometry. Expression of p21(waf1/cip1) and Akt as well as activation of Akt in PC-3 cells were detected by Western blot and Real-time PCR.

RESULTS

Silencing of Notch-1 promoted docetaxel induced cell growth inhibition, apoptosis and cell cycle arrest in PC-3 cells. In addition, these effects were associated with increased p21(waf1/cip1) expression and decreased Akt expression and activation in PC-3 cells.

CONCLUSION

Notch-1 promotes chemoresistance of prostate cancer and could be a potential therapeutic target.