Vitamin C increases the apoptosis via up-regulation p53 during cisplatin treatment in human colon cancer cells.

Vitamin C (VC) is an important antioxidant and enzyme co-fac-tor that works by stimulating the immune system and protect-ing against infections. It is well known that melanoma cells are more susceptible to VC than any other tumor cells. However, the role of VC in the treatment of colon cancer has not been studied. Cisplatin (CDDP) is a DNA damaging agent and is widely used for treating cancer, while the role of p53 in CDDP-induced cell death has been stressed. Using cell growth assays, morphological methods, Western blotting, flow cy-tometry, and DNA fragmentation analysis, we measured the expression of p53 level involved in the effect of VC on CDDP-induced apoptosis of HCT116, a human colon cancer cell line. CDDP plus VC treatment resulted in significantly in-creased apoptosis along with upregulation of p53 compared to untreated cells and/or CDDP-treated cells. These results sug-gest that VC enhanced CDDP sensitivity and apoptosis via up-regulation of p53. [BMB reports 2011; 44(3): 211-216]