The Changes of Expression of Survivin by Butyrate in HCT116 Colon Cancer Cells

Purpose: The causes of colon cancer can be divided into genetic and environmental components. A high-fiber diet is known to reduce the risk of colon cancer. Dietary fiber is converted to short chain fatty acid, butyrate, in the colon by bacteria. Butyrate is used as an energy source for the colonic epithelial cells, and is known to induce apoptosis in colon cancer cell lines. Survivin, a recently discovered member of the IAP (inhibitor of apoptosis) family, is known to suppress apoptosis. Not only does it suppress cell apoptosis, but it also has a protective effect from disabling G2/M phase of the cell cycle by attaching to the microtubule of the mitotic spindle. The purpose of this study is to evaluate the effect of butyrate on the expression of survivin, in HCT116 colon cancer cell lines. Methods: Cytotoxicity of butyrate was measured by MTS method. Cell cycle phase and apoptosis was analyzed by flowcytometry. Protein expression of survivin was evaluated by Western blot analysis, and the mRNA expression by RT-PCR. Results: Butyrate can induce apoptosis in HCT116 colon cancer cell line at a concentration of 6 mM. Butyrate suppressed the expression of survivin mRNA and also the expression of cytosolic and nuclear survivin. In flowcytometric analysis, the apoptotic portion was increased and the proportions of S and M phase were decreased when cultured with butyrate. Conclusion: We concluded that butyrate could induce cellular apoptosis partially by suppressing the expression of survivin in HCT116 colon cancer cells. (J Korean Surg Soc 2009;77:297-305)