Inhibitory Effects Of Octreotide On Prostate Cancer PC-3 Cell Line And The Expression Of VEGF

Objective:To investigate the inhibitory effects of octreotide (somatostatin analogs) on androgen-independent prostate cancer PC-3 cell line and the expression of vascular endothelial growth factor(VEGF).Methods:After PC-3 cells were induced by 0.1,0.3,1.0,3.0mg/L octreotide respectively, the cell activity was assayed by MTT at 24,48 and 72 hours, the morphology of apoptosis was observed by Hoechst 33258 staining under fluorescence microscope. The level of caspase-3 and VEGF were detected by reverse transcription-polymerase chain reaction(RT-PCR).Results:Octreotide could suppress the growth and promote the apoptosis of PC-3 cells. When cells were treated with different concentrations of octreotide (0.1,0.3, 1.0and 3.0mg/L), the cell surviving rate was (0.971±0.016)%,(0.853±0.015)%,(0.717±0.031)%,(0.743±0.029)% respectively at 24hours,(0.918±0.015)%,(0.835±0.015)%,(0.682±0.018)%,(0.727±0.014)% respectively at 48hours and (0.922±0.017)%,(0.841±0.013)%,(0.717±0.017)%,(0.739±0.003)% respectively at 72hours, the difference was obviously significant (P<0.01) among them. When cells were treated with different concentrations of octreotide as upon at 48hours, the expression of VEGF mRNA was 0.227±0.025,0.113±0.006,0.027±0.001,0.071±0.004 respectively, each group among them had a lower expression than the control group(0.546±0.0266), the difference was significant(P<0.01),especially the 1.0mg/L group. When cells were treated with 1.0mg/L octreotide at 24,48 and 72 hours, the expression of VEGF mRNA was 0.461±0.038,0.027±0.002,0.343±0.028 respectively, there was a significant difference among them (P<0.01) and the 48 hour group had the least expression. Under the same condition, when cells were treated with different concentrations at 48hours, the expression of Caspase-3 mRNA was 0.246±0.008,0.516±0.009,1.024±0.092,0.619±0.009 respectively, each group among them had a higher expression than the control group (0.055±0.005), the difference was significant (P<0.01) especially the 1.0mg/L group. When cells were treated with 1.0mg/L octreotide at 24,48 and 72 hours, the expression of Caspase-3 mRNA was 0.033±0.002,1.024±0.092,0.510±0.013 respectively, there was a significant difference among them (P<0.01) and the 48 hour group had the most expression.Conclusions:Octreotide can suppress the proliferation of PC-3 cells, and its possible mechanism is inhibiting the expression of VEGF mRNA, reducing angiogenesis and inducing apoptosis.