Enhances the Effects of Chemotherapeutic Agents in Human Breast Cancer Cells withDownregulation of XIAP Expression by RNAi

Breast cancer is the second leading cause of death by cancer in among women. Resistance to therapy is the most cause of treatment failure in cancer therapy. Resistance of cancer cells to cytotoxic drugs may be a result of resistance to apopotosis. XIAP (X-Linked Inhibitor of Apoptotic Protein) overexpression can be overcome cytotoxic effects of many chemotherapeutic agents in breast cancer by inhibiting apoptosis.In this study, XIAP gene was inactivated by RNAi approach in breast cancer cells. Inactivated cells were treatmented with chemotherapeutic agents; like etoposide or doxorubicin or taxanes. Cells growth, viability and apoptosis studies were performed.Findings shows that Reducing XIAP protein expression increases MDA-MB-231 cells susceptibility to taxenes. Down-regulation of XIAP also sensitizes MCF-7 breast cancer cells to killing by etoposide and doxorubicin. Therefore, downregulation of XIAP increases the effectiveness of chemotherapeutic agents by inducing apoptosis in breast cancer cells.

Keywords:

Chemotherapy , XIAP , breast cancer