Comparison of in vitro activity of cytotoxic drugs towards human carcinoma and leukaemia cell lines.

Eight human haematopoietic cell lines and four human carcinoma lines were used to compare the activity of a number of cytotoxic drugs including amsacrine, the amsacrine analogue CI-921, methotrexate, nitracrine, doxorubicin, daunorubicin and 5-fluorouracil. Activity was assessed by means of semiautomated microculture growth inhibition assays. Cell density of the non-adherent cell lines was measured using the technique of Mosmann (J Immunol Methods 1983, 65, 55-63), in which the dye thiazolyl blue (MTT) is metabolised to a dark blue formazan product. This technique gives similar results to those obtained by direct cell counting in an electronic cell counter, and when applied to some adherent cell lines gives similar results to those obtained by the methylene blue staining technique previously developed (Anal Biochem 1984, 139, 272-277). Both methylene blue and MTT methods were used to investigate cytotoxicity in conjunction with semi-automated 96-well microculture plate techniques. The results show that the three T-cell leukaemia lines (CCRF-CEM, Jurkat and MOLT-4) are more sensitive to DNA-binding drugs (excluding nitracrine) than are the colon carcinoma lines (HCT-8, HT-29, SW480 and SW620). The more resistant haematopoietic lines are intermediate in drug sensitivity between the T cell leukaemia and carcinoma lines. The DNA binding drugs show remarkably similar patterns of differential activity against the different cell lines.