Objective:The aim of our study was to investigate the effects of Pin1 reduction on SW620 cell proliferation and apoptosis in human colorectal carcinoma.Methods:We constructed a plasmid of RNA interfering(shRNA) for Pin1 gene(pGenesl-1-Pin1),then the plasmid was transfected into colorectal carcinoma SW620 cells line by liposome mediation.The protein expression of Pin1 was tested by Western blotting.The proliferation rate was analyzed by MTT and the apoptotic rate of cells was tested by flow cytometry.In order to explain further the effect of Pin1 in SW620 cells,the protein level of Bcl-2 was analyzed by Western blotting.Results:pGenesil-1-Pin1 plasmid was successfully constructed and confirmed by sequencing.The protein relative levels of Pin1 were 0.06 ± 0.04 for the P-shRNA/SW620 cells,and 0.32 ± 0.09 for the P-Con/SW620 cells.The cell growth rate of SW620 cells was slower while the apoptotic rate was increased after transfection with pGenesil-Pin1 plasmid,and the apoptotic rate was 12.38% ± 1.55% for the P-shRNA/SW620 group.At the same time,we found that the protein expression of Bcl-2 was also reduced.The results were 0.13 ± 0.04 for the P-shRNA/SW620 cells,and 0.36 ± 0.08 for the P-Con/SW620 cells.Conclusion:Inhibited Pin1 expression may suppress the cell proliferation and promote apoptosis of colorectal carcinoma cells in vitro. Objective: The aim of The study was to investigate the effects of Pin1 reduction on SW620 cell proliferation and apoptosis in human colorectal carcinoma. Methods: We constructed a plasmid of RNA interfering (shRNA) for Pin1 gene (pGenesl-1-Pin1), then the plasmid was transfected into colorectal carcinoma SW620 cells line by liposome mediation.The protein expression of Pin1 was tested by Western blotting. The proliferation rate was analyzed by MTT and the apoptotic rate of cells was tested by flow cytometry. In order to explain further the effect of Pin1 in SW620 cells, the protein level of Bcl-2 was analyzed by Western blotting. Results: pGenesil-1-Pin1 plasmid was successfully constructed and confirmed by sequencing. The protein relative levels of Pin1 were 0.06 ± 0.04 for the P- shRNA / SW620 cells, and 0.32 ± 0.09 for the P-Con / SW620 cells. The cell growth rate of SW620 cells was slower while the apoptotic rate was increased after transfection with pGenesil-Pin1 plasmid, and the apoptotic rate was 12.38% ± 1.55% for the P-shRNA / SW620 group. At the same time, we found that the protein expression of Bcl-2 was also reduced. The results were 0.13 ± 0.04 for the P-shRNA / SW620 cells, and 0.36 ± 0.08 for the P-Con / SW620 cells. Confluence: Inhibited Pin1 expression may suppress the cell proliferation and promote apoptosis of colorectal carcinoma cells in vitro.