Abstract

SK-30ZB with quinomycin-related structure is considered to be potent antitumor antibiotic. There were several reports that quinomycins and their derivatives showed wide spectrum of anti-tumor activity. But there were no reports on anti-gastric tumor activity. We fould SK- 302B with anti-gastric tumor activity in vitro using our established anti-tumorsubstance screening system. Recent attention has been focused on the possibility of predicting the effectiveness of anti-cancer drugs on individual tumor through chemosensitivity tests. However, optimal conditions for in vitro chemosensitivity test on human gastric carcinoma cell lines were not well established. We attempted to establish optimal conditions and to evaluate compara- tively in vitro tumor cell cytotoxicity between SK-302B and adriamycin, using 7 human gastric carcinoma celi lines. The optimal cell number and culture duration for in vitro tumor cell cytotoxicity(TCC) and colony formation inhibition assay(CFIA) is 5x10(3) - 1x10(4) cells/well (TCC) and 2.510(3) - 10(3) cells/well(CFIA), 4 days(TCC) and 10 - l4 days(CFIA), respectively, for all gestric cancer cell lines. Under these conditions, we performed chemosensitivity test. Measurement of cytotoxicity(IC50) and colony forming efficiency revealed higher tumoricidal activity of SK-302 B against all tested gastric cancer cell lines than compared to that of adriamycin. In conclusion, we preseneted optimal conditions for in vitro chemosensitivity test on human gastric carcinoma cell lines. Using optimal conditions of this sytem, it could be demonstrated that SK-302B exerted a potent gastric cancer cell growth inhibition in vitro. Therefor, These data suggest that SK-302B may have a possibility of development as promising candidate of anti-gastric cancer chemotherapeutic agent.

• Keywords: SK-302B, Gastric carcinoma cell line, Chemosensitivity