Influence of feline sarcoma-related protein on cell cycle and apoptisis of human prostate cancer cells and the mechanism

Objective To investigate the influence of small interference RNA(siRNA) silencing feline sarcoma-related protein(Fer)on cell cycle and apoptosis of prostate cancer cells. Methods PC-3 cells were transfected with three siRNAs targeting human Fer by liposome transfection reagent.Real -time reverse transcriptase-polymerase chain reaction(RT-qPCR) and Western blotting were used to detect the expression of Fer mRNA and protein respectively, and the most efficient siRNA was screened out for the following experiments.The cell cycle and apoptosis rate were analyzed by flow cytometry.Furthermore, we observed the expression levels of the cell cycle-and apoptosisrelated genes in the transfected cells with down-regulation of the Fer expression. Results RT-qPCR showed that Fer mRNA relative expression levels of three siRNAs was 0. 288,0. 369 and 0. 623, respectively, which were significantly lower than those in the negative control group(l,P< 0. 05).Western blotting also demonstrated that the expression of Fer protein in PC-3 cells transfected with three siRNAs could significantly inhibited,and siRNA-1 was selected as the most efficient siRNA(P<0. 01).Flow cytometry revealed the percentage of G0/G1 phase cells in RNAi(Si) group was(52. 340± 2. 049)%, significantly higher than that in negative control group[(40. 230±2. 065)%](P< 0. 05), and that of S phase cells was(35. 040±3. 810)%, significantly lower than that in the negative control group[(50. 650±3. 693)%](P< 0. 05). The apoptosis rate in Si group was(33. 6± 3. 3)%, significanfly higher than that in negative control group[(7. 8±1. 0)%](P< 0. 05).Meanwhile, with the inhibition of Fer, the expression levels of Cyclin D1 and B cell lymphoma/leukemia-2(bcl-2) were reduced obviously, and p21 and cleaved Caspase-3 upregulated obviously as compared with negative control group(P< 0. 05). Conclusion Fer-siRNA could significantly inhibit the expression of Fer and the progression of G1/S in human prostate cancer cells, and then induced apoptosis of PC-3 cells in vitro.The mechanism probably correlates with regulation of the cell cycle -and apoptosis-related genes expression. Key words: Prostate cancer; Feline sarcoma-related protein; Small interfering RNA; Cell cycle; Apoptosis