Abstract: Objective To study the effects of PIAS3 knocking down on proliferation, cell cycle and apoptosis of human prostate cancer cell line DU145. Methods PIAS3 specific short hairpin RNA(shRNA) expressing plasmid was constructed and named pSilencer4.1/PIAS3.DU145 cell was transfected with pSilencer4.1/PIAS3. The proliferation of DU145 cells was analyzed by MTT assay.Cell cycle and apoptosis of DU145 cells were analyzed by flowcytometry. Results PIAS3 shRNA expressing plasmid was constructed succefully,confirmed by sequencing.Expression of PIAS3 in DU145 was reduced significantly after pSilencer4.1/PIAS3 transfection. MTT assay shown accelerated proliferation after PIAS3 knocking down,and shown dose-effect curve. Flowcytometry shown cells in S phase increased,cells in G0/G1 decreased and percentage of apoptotic cells decreased after PIAS3 knocking down.Conclusion The knocking down of PIAS3 expression could accelerate DU145 cell proliferation and inhibit cell apoptosis.

Key words: Prostate carcinoma, Protein Inhibitor of Activated STAT3, RNA interference, Apoptosis