Inhibitory effect of siRNA targeting survivin in gastric cancer MGC-803 cells

Gastric cancer is the fourth most common cancer in the world and the leading cause of cancer death in China. It is necessary to find a safe and effective way to treat this disease. A sustained overexpression of survivin is a characteristic feature of gastric cancer as it gives cancer cells a survival and growth advantage. RNA interference (RNAi), which has been proven to be a powerful tool, for suppressing gene expression, may provide a promising way forward in gastric cancer therapy. Few studies have been conducted on the inhibitory effects of small interfering RNA (siRNA) against survivin in gastric cancer. In this study, we constructed the recombinant Psilencer 2.1-survivin siRNA plasmids and transfected them into gastric cancer MGC-803 cells in vitro, and also injected MGC-803/Silence (+) cells into nude mice to observe the inhibitory effects in vivo. The transfection of Psilencer 2.1-survivin (+) plasmid led to remarkable inhibition of survivin mRNA expression, the intensity of survivin mRNA was tower (P<0.05), the expression of survivin protein was strongly suppressed, the amount of survivin protein was also lower (P<0.05) and the percentage of apoptotic cells was much higher (P<0.05). The tumor size and growth ratio were lower in nude mice injected with MGC-803/Silence (+) cells and the inhibition ratio of survivin expression was higher (P<0.05). In summary, siRNA targeting of survivin can effectively inhibit the growth of gastric cancer cells and may be used as a potent therapy. (C) 2008 Elsevier B.V. All rights reserved.