Introduction of gadd153 gene into gastric cancer cells can modulate sensitivity to anticancer agents in association with apoptosis.

Gadd 153 gene is known as one of the growth arrest and DNA damage inducible genes that may play an important role in signal transduction pathway(s) in response to DNA damage. We have investigated whether the introduction of gadd153 gene into gastric cancer cells could modulate the sensitivity to anticancer agents in association with apoptosis. The transfection of gadd153 gene into MKN45 gastric cancer cells (MKN45gadd153) increased the sensitivity to a variety of anticancer agents, compared to that of neo gene-transfected cells (MKN45neo). The sensitivity to CDDP and VP-16 was increased to a greater extent, whereas the sensitivity to 5-FU and taxotere was increased to a lesser extent. The increase of sensitivity to these drugs was associated with the increase of the formation of internucleosomal DNA ladders in apoptosis. The basal level of gadd153 mRNA was overexpressed in MKN45gadd153 cells, and its induction following the treatment of VP-16 and taxotere was found to a greater extent than that of MKN45neo cells. The analysis of mRNA expression in drug resistance-related genes including mdr1, mrp, topoisomerase II alpha showed that the increase of drug-sensitivity in MKN45gadd153 cells was not due to the changes in expression of drug resistance genes. These results suggest that the introduction of gadd153 gene into gastric cancer cells may modulate the sensitivity to certain anticancer agents by activating AP-1-associated signal transduction pathway(s) leading to apoptosis.