CRITICAL PARAMETERS INFLUENCING HYPERTHERMIA-INDUCED CELL DEATH IN MYELOGENOUS LEUKEMIA CELL LINE (M-NFS-60)

Hyperthermia is sufficient to induce cell death in many cancer cells. Here we investigated the effect of some parameters that modulate hyperthermia-induced cell death in myelogenous leukemia cell line (M-NFS-60). Trypan blue exclusion method was used to measure M-NSF-60 cell viability after heat exposure to different temperatures (39, 41 and 43 oC) for different periods of time (15, 30 and 60 min). Induced apoptotic cell death after heat exposure was investigated by western blot analysis for the expression level of active caspase-3 protein. The results of this work revealed that M-NFS-60 cells respond to hyperthermia in a graded fashion depend on heat load, time exposure and cell density. Heat exposure at 39 oC and 41 oC for 15, 30 and 60 min and at 43 oC for 15 min caused cell growth arrest, however, at 43 oC for 30 and 60 min it gradually inhibited the growth of M-NFS-60 cells. These data suggest that heat stress at 43 oC at least for 30 min and more has therapeutic efficiency in leukemic cells. Finally, we determined heat load, time exposure and cell density as critical parameters influenced cytotoxic effect of hyperthermia on leukemic cells.