Abstract
A regrowth assay method for many in vitro anticancer agent sensitivity tests was examined using established human lung cancer cell lines. It was demonstrated experimentally that it precisely reflected the division delay of the cells exposed to anticanceragents. As most sensitivity tests do not sufficiently allow for the fact that cancer cells have different sensitivities in each phase of the cell cycle, we have devised a new method of measuring the total cell-kill concentration which makes it possible to disregard these differences. The sensitivities of two established human lung cancer cell lines (QG56 and QG90) to Mitomycin-C and Adriamycin were measured by our method. Mitomycin-C had cell cycle phase specificity, and could not yield total-cell-kill even at the high concentration of 15mcg/ml. On the other hand, Adriamycin showed cell cycle phase nonspecificity, and yielded total-cell-kill at a concentration of 10mcg/ml. However the concentration of 10mcg/ml is much higher than the clinically attainable concentration in human serum.
