Different susceptibility of colon cancer DLD-1 and LOVO cell lines to apoptosis induced by DMU-212, a synthetic resveratrol analogue

• DMU-212 induced mitochondria-mediated apoptosis in both colon cancer cell lines DLD-1 and LOVO.
• DMU-212 triggered the greater pro-apoptotic effect in DLD-1cells in which its stronger cytotoxic activity was observed.
• DMU-212 blocked CYP1B1 mRNA and protein expression in DLD-1 cells.

The cytotoxic activity of DMU-212 has been shown to vary in cell lines derived from the same type of cancer, i.e. ovarian, breast and colorectal ones. However, the molecular mechanism of DMU-212 cytotoxicity has not been clarified in colon cancer cells. This study aims to elucidate the mechanism of antitumor effects of DMU-212 in two human colon cancer cell lines, DLD-1 and LOVO. We showed the stronger cytotoxic activity in DLD-1 cells in which DMU-212 evoked a greater pro-apoptotic effect as compared to that of LOVO cells. The analysis of the expression pattern of 84 apoptosis-related genes indicated transcripts specific to the mitochondria-mediated apoptosis pathway in both colon cancer cell lines used. We found that DMU-212 caused up-regulation of pro-apoptotic Bak1, Bok, Bik, Noxa, Bad, Bax, p53 and Apaf1 transcripts level in DLD-1 cell line, whereas anti-apoptotic Bcl-2, Bcl-xL and Bag1 mRNA expression was decreased. Changes in apoptosis-related genes expression were less pronounced in LOVO cells which did not express CYP1B1 protein and showed lower expression of CYP1A1 protein level than that in DLD-1 cells. Our results suggest that anticancer activity of DMU-212 is closely related to its biotransformation catalysed by these cytochrome P450 isoenzymes.