Caffeine modulates heat shock induced apoptosis in the human promyelocytic leukemia cell line HL-60

The ability of caffeine to modulate hyperthermia induced apoptosis was investigated in the human promyelocytic cell line HL60. Mild hyperthermia has been shown to be a strong inducer of apoptosis in many cell lines of lymphoblastoid lineage. In this investigation HL60 cells were simultaneously exposed to caffeine (concentrations ranging from 0 to 20 mM), and a brief hyperthermic treatment (43 degrees C) for 1 h and then allowed a recovery time of 12 h. Approximately 50% of a cell population receiving the hyperthermia treatment died by apoptosis within 12 h, as determined by the comet assay, whereas cells that received concomitant treatments of caffeine with heat shock displayed an apparent suppression of apoptotic induction and enhanced cell survival.