Abstract
Effects of gastrointestinal hormones on the growth of cultured human stomach cancer cells were studied with the microplate labeling assay (M. L. A.) and the human tumor clonogenic cell assay (H. T. C. A.) which are widely used asin vitrosensitivity tests of anticancer drugs. MKN-28 (well differentiated adenocarcinoma), MKN-45 (poorly differentiated adenocarcinoma), and KATO III (signet-ring cell carcinoma) were chosen as three different kinds of cultured cell lines. Effects of gastrin, secretin and G. I. P. on the growth of those cultured cells were evaluated with a3H-TdR up take rate in M. L. A. and a colony formation rate in H. T. C. A., respectively. Gastrin induced a marked increase in a3H-TdR up take rate but no significant change in a colony formation rate for MKN-45 and KATO III. On the other hand, gastrin did not induce any significance in an either measurement for MKN-28. Secretin induced no change in a3H-TdR up take rate or a colony formation rate for MKN-45 and MKN-28. As for KATO III, however, administration of 10.0 U/ml and 1.0 U/ml of secretin induced a 15% decrease in a3H-TdR up take rate and 20% decrease in a colony formation rate, respectively. G. I. P. lowered a3H-TdR up take rate for all of the three cell lines, but did not make significant changes in a colony formation rate for any cell line. This study clearly showed the inhibitory effect of secretin on the growth of KATO III. It may strongly suggest the effectiveness of G. I. hormones for the treatment of gastrointestinal carcinomas.
