Abstract
Lonidamine (LND), an indazole-carboxylic acid derivative, was delivered alone and together with adriamycin (ADM) or hyperthermia to the human melanoma cell line M14, and cell survival was assessed. Cell cycle-specific effects were investigated by analyzing sequences of DNA content histograms by means of a suitable mathematical procedure. LND delivered for 1 h at a dose of 50 micrograms/ml did not affect proliferation and survival of the cells. Exposure of the cells for 1 h to ADM (1.0 microgram/ml) followed by LND for 1 h (50 micrograms/ml) produced the highest effect on the survival. Kinetic parameters were affected by the combined treatment slightly more than by ADM exposure alone. Simultaneous delivery of LND (50 micrograms/ml) with hyperthermia (42 degrees C, 1 h) reduced the survival and enhanced the block of cells in the G2M phase, as compared with the heat treatment alone. The effect of the treatments on cell survival appeared to be related to the perturbation of the G2M phase of the cycle.