The effect of lonidamine alone and in combination with cisplatin on in vitro growth and viability of lung squamous cell carcinoma cell lines.

Two non small cell lung cancer (NSCLC) cell lines were tested in vitro to evaluate the effect of lonidamine, cisplatin and combinations of these two agents using different doses and schedules. Lonidamine alone at concentrations greater than 50 micrograms/ml caused inhibition of cell growth in both monolayer and spheroid cell cultures. Cisplatin at concentrations of 10-20 microM caused a concentration dependent toxicity and inhibited growth in monolayer and spheroid cell cultures. Combination treatment of lonidamine and cisplatin caused concentration dependent effects. For 25 micrograms/ml lonidamine, there was no additive and in some cases an antagonistic effect when used with cisplatin. For higher lonidamine concentrations (75 and 100 micrograms ml), an additive effect with cisplatin (10-15 microM) was observed. This effect saturated for cisplatin concentrations of 20 microM. These data show some potential for lonidamine and cisplatin combination therapy but treatment doses and schedules will have to be identified so that the additive effect can be achieved at concentrations clinically attainable.