Effects of downregulation of osteopontin on biological behavior of prostate cancer PC3 cells

Objective To study the effects of downregulation of osteopontin (OPN) on biological behavior of prostate cancer PC3 cells. Methods OPN expression in PC3 cells was knocked down atter using vector-based small interference RNA(siRNA) targeting to OPN. The expression of OPN was analyzed by RT-PCR and western blot. The growth activities of the transfected PC3 cells were detected by MTT assay. Alterations of cell cycle and apoptosis in the transfected PC3 cells were examined by flow cytometry. Anchorage-independent growth was measured by colony formation in soft agarose. Results The obvious inhibition of OPN expression in the transfected cells was confirmed by RT-PCR and western blot. The depression of cell growth was examined by MTT assay. S-phase arrest and apoptosis in the transfected cells were observed by flow cytometry. The number and size of the colonies of the transfected cells in soft agarose were obviously decreased,as compared with that of parent cells. Conclusion Selective downregulation of OPN expression in PC3 cells by RNAi could lead to S-phase arrest and apoptosis, and decline malignant phenotype for the malignant cells.