EFFECT OF TRANS-RETINOIC ACID AND FOLIC-ACID ON APOPTOSIS IN HUMAN GASTRIC-CANCER CELL-LINES MKN-45 AND MKN-28

Induction of apoptosis has been implicated as an anticarcinogentic mec hanism of both folic acid and retinoic acid. The ability of retinoic a cid or folic acid to induce gastric cancer cell apoptosis was investig ated in the human gastric cancer cell lines MKN-45 and MKN-28, and DNA fragmentation was studied in situ by terminal deoxynucleotidyl transf erase-mediated dUTP-biotin nick end labeling and DNA agarose gel elect rophoresis. The rates of apoptosis in both the poorly differentiated M KN-45 and the well differentiated MKN-28 cell line were less than 5% a fter treatment with either retinoic or folic acid. Apoptosis may be in duced by the administration of retinoic acid or folic acid, and the ap optosis indices of MKN-45 and MKN-28 cells were related to the doses o f these drugs. The induction of gastric cancer cell apoptosis may play a role in the anticarcinogenetic effect of retinoic acid and folic ac id, both of which are potential agents for the treatment of human gast ric cancer.