Knockdown of surviving expression by RNAi induces apoptosis in HeLa cells

Evasion of apoptosis is a hallmark of cancer, but the molecular mechanisms of this process are not fully understood. Survivin, a member of the inhibitor of apoptosis gene family, is overexpressed in most human tumors, particularly in those resistant to therapy. This quality makes it attractive as a potential target in cancer therapy. In this study, RNA interference (RNAi), a novel technique, was employed to knockdown target gene levels and protein expression to reduce survivin expression in HeLa cells. The pSUPER RNAi system, which provides a mammalian expression vector that directs intracellular synthesis of siRNA-like transcripts, was used. Three targeting sequences—SUR1, SUR2, and SUR3—were selected. These sequences successfully knocked down survivin mRNA levels in HeLa cells, which in turn experienced increased apoptosis. To determine the effect of knocking down survivin on apoptosis, the p53 gene, which is the correlative gene of apoptosis, was studied. RT-PCR assays show that as survivin expression diminished, the level of p53 increased. This result demonstrates that survivin RNAi influences the apoptosis of HeLa cells. Given that survivin plays such a significant role in cancer, knocking down its expression efficiently can have an important therapeutic benefit.