Cisplatin-resistant Human Small Cell Lung Cancer Cell Line Shows Collateral Sensitivity to Vinca Alkaloids

A cisplatin-resistant cell line, SBC-3/CDDP, was established from a human small-cell lung cancer cell line, SBC-3. The SBC-3/CDDP cells were 13.1-fold more resistant to cisplatin than the parent SBC-3 cells. We investigated the cellular changes of this cell line with regard to the development of resistance to cisplatin. The SBC-3/CDDP cells showed various characteristics as follows: a) increased intracellular glutathione and glutathione S-transferase content b) decreased intracellular accumulation of cisplatin, c) increased topoisomerase I activity and the same topoisomerase II activity as the parent SBC-3 cells, and 4) strong cross-resistance to the platinum analogues and mitomycin C, moderate cross-resistance to 7-ethyl-10-hydroxy-camptothecin (SN-38), 4-hydroperoxy cyclophosphamide, etoposide, Adriamycin and methotrexate, and collateral sensitivity to vinca alkaloids and 5-fluorouracil. From these observations, the SBC-3/CDDP cells could be useful as a well characterized cisplatin-resistant cell line, and the resistance pattem in this cell line will give us much information for eradication of cisplatin-resistant tumor cells.