siRNA-Mediated Silencing of CIP2A Enhances Docetaxel Activity Against PC-3 Prostate Cancer Cells.

Purpose: Cancerous inhibitor of protein phosphatase 2A (CIP2A) is an identified human oncoprotein which modulates malignant cell growth. It is overexpressed in human prostate cancer and in most of the human malignancies. The aim of this study was to investigate the effects of CIP2A silencing on the sensitivity of PC-3 prostate cancer cells to docetaxel chemotherapy. Methods: PC-3 cells were transfected using CIP2A siRNA. CIP2A mRNA and protein expression were assessed after CIP2A gene silencing using q-RT PCR and Western blotting. Proliferation and apoptosis were analyzed after treatment with docetaxol using MTT assay, DAPI staining, and flow cytometry, respectively. Results: Silencing of CIP2A enhanced the sensitivity of PC-3 cells to docetaxel by strengthening docetaxel induced cell growth inhibition and apoptosis against PC-3 cells. Conclusion: Silencing of CIP2A may potentiate the cytotoxic effects of docetaxel and this might be a promising therapeutic approach in prostate cancer treatment.