Effect of indomethacin on cell cycle proteins in colon cancer cell lines

AIM: To study the effect of indomethacin (IN) on human colon cancer cell line SW480 with p53 mutant and SW480 transfected wild-type p53 (wtp53/SW480) in vitro and investigate molecular mechanism of anti-tumor effect of IN on colon cancer. METHODS: SW480 cells and wtp53/SW480 cells were treated with different concentrations of IN respectively, the expressions of CDK2, CDK4 and p21WAF1/CIP1 protein were detected by Western blotting. RESULTS: IN gradually down-regulated the expression of CDK2, CDK4 protein of wtp53/SW480 cells in a dose-dependent manner, and inhibitory effect reached the maximum level at 600 micromol/L; IN up-regulated the expression of p21 WAF1/CIP1 protein in a dose-dependent manner at a certain concentration range, and the expression reached the maximum level at 400 micromol/L, and returned to the base level at 600 micromol/L. The expression of CDK2, CDK4 and p21WAF1/CIP1 protein of SW480 cells did not change. CONCLUSION: IN exerts antitumor effect partly through down regulation of the expression of CDK2, CDK4 protein and up regulation of the expression of p21WAF1/PIC1.