Objective To investigate the effect of dsP21-555 on cell cycle and proliferation of prostate cancer cell line PC-3 and LNCaP. Methods dsP21-555 (experimental group) and dsControl (negative control group) were transfected into PC-3 and LNCaP, respectively. Real-time PCR and Western Blotting were used to detect the expression of p21 mRNA and p21 protein in prostate cancer cells after transfection. The cell cycle distribution was detected by flow cytometry. Cell viability and proliferation were measured by MTT assay and colony forming assay. Results The level of p21 mRNA in PC-3 and LNCaP cells was increased to 2.90-fold (P<0.01) and 2.05 - fold (P<0.01) respectively after transfection with dsP21-555. Western Blotting results were consistent with this trend. Flow cytometry showed that the percentage of cells in S phase and G2 / M phase decreased after transfection with dsP21-555, and the proportion of cells in G0 / G1 phase increased. MTT assay showed that the viability of PC-3 and LNCaP cells significantly decreased after dsP21-555 transfection compared with dsControl group. The colony formation assay showed that the number of colonies in the dsP21-555 group was fewer and the cell proliferation ability decreased. Conclusions Synthesized dsP21-555 can significantly activate the expression of p21 gene in prostate cancer cells and significantly inhibit the progression of cell cycle and proliferation ability of prostate cancer cells.
