In vitro antitumor effect of topoisomerase-I inhibitor, CPT-11, on freshlyisolated human gastric and colorectal cancer

CPT-II is a camptothecin analogue which has shown a broad spectrum of stron g antitumor effect against various cancers, including gastroenterological m alignancies. In the present study, the antitumor effect of CPT-II was deter mined by MTT assay for freshly isolated human gastric and colorectal cancer cells, especially highly purified tumor cells. Twenty-thr ee patients with gastric cancel; and 32 patients with colorectal cancer were e,nrolled jn t his study. Three gastric and 3 colonic cancer cell lines were used to study the antitumor effect of CPT-11, and freshly isolated cancer cells from 3 p atients with gastric cancer were investigated. The in vitro antitumor effec t was tested by MTT assay and showed % inhibition rate. CPT-11 and SN-38 sh owed the antitumor effect as a dose dependent matter for human gastric and colorectal tumor cells in vitro. From the results of chemosensitivity for f reshly isolated gastric and colorectal tumor cells, antitumor effect of SN- 38 was as strong as other conventional anticancer agents. It was demonstrat ed that the MTT assay was appropriate for the analysis of the antitumor eff ects of CPT-II and SN-38, and that CPT-II may be a worthwhile choice as an anticancer agent against gastric and colorectal cancer.