Angiocytotoxic Therapy in Human Non-Small Cell Lung Cancer Cell Lines: Advantage of Combined Effects of TNP-470 and SN-38

The combined effects of TNP-470, a promising antiangiogenic agent, and SN-38, a camptothecin derivative, were evaluated in four human cultured cell lines derived from non-small cell lung cancer (NSCLC). Cytotoxicity experiments were determined by using a tetrazolium salt (MTT) assay. The inhibitory effects of TNP-470 on cell proliferation were dose related and the 50% inhibitory concentrations on these cell lines were 47.3-139.8 microM. Evaluation of drug interactions with isobologram and the combination index values showed that sequential exposure to SN-38 followed by TNP-470 produced synergistic effects in the four cell lines tested. Our findings suggest that such an angiocytotoxic chemotherapy might be promising for the treatment of NSCLC.