OBJECTIVETo explore the effects of cyclopamine on the proliferation and apoptosis of LNCaP cells and the expression of the PCA3 gene in human prostate cancer in vitro.

METHODSLNCaP cells were treated with cyclopamine at the concentrations of 1, 5, 10 and 15 micromol/L for 24, 48 and 72 hours. The inhibitory effects of cyclopamine on the proliferation and apoptosis of the LNCaP cells were detected by MTT and flow cytometry respectively, the morphological changes of the cells observed by Hoechst 33258 staining, and the expression of the PCA3 gene determined by real-time fluorescence quantitative reverse transcriptase polymerase chain reaction (FQ-RT-PCR).

RESULTSCompared with the blank control group, cyclopamine significantly inhibited the proliferation of the LNCaP cells at 5, 10 and 15 micromol/L (P <0.01), reaching IC50 at 10 micro mol/L at 48 hours. The apoptosis rates of the LNCaP cells at 24, 48 and 72 hours were 37.21%, 57.38% and 57.98% in the 10 micromol/L group and 21. 16% , 71.31% and 72.90% in the 15 micro.mol/L group, significantly different from those in the control (P <0. 01). The cell apoptosis showed a rising trend with the increase of cyclopamine concentration and acting-time, while the expression of the PCA3 gene was decreasing with the increased concentration of cyclopamine, significantly lower than that of the blank control group (P <0.01) , and extremely low in the 10 micromo/L group

CONCLUSIONCyclopamine intervention at 10 and 15 micromol/L for 48 and 72 hours could significantly inhibit the at all time points. Proliferation and induce the apoptosis of LNCaP cells and reduce the expression level of PCA3.