ABSTRACT
AIM To establish the expermental model in vitro for the study of mechanism of antitumor drug resistance and the screening of antitumor drug. METHODS By continuously exposing cells to gradually increasing concentration of drug and agar cell colony forming technique, using dye exclusive method for determing cytotoxic effect, a murine leukemia L1210 cell subline were established,which exhibited 40 fold resistance to Cis diamminedichloro platinum(DDP). RESULTS The doubling times, plate efficiency, cell cycle, DNA index and cell morphology of DDP resistant L1210 subline were similarto those of its parant cell line. When the cell subline was stored with DDP at -196℃ for 6 months and then was recovered, its characterization of antitumor drug resistance was still maintained to a period of 5 months without DDP. DDP resistant L1210 subline was characterized with cross resistance to Carboplatin, Mitomycin, Thio Tepa, Methotrexate, Vincristin and Mustine Hydrochloride, but with no cross resistance to Harringtonine and Adriamycin. It was seemed more sensitive to Cytarabine and Fluorouracil. CONCLUSION DDP resistant L1210 subline is a good experimental model in vitro for the study of mechanism of antitumor drug resistance and the screening of antitumor drug.