Mechanisms of mild hyperthermia-induced cytotoxicity in human prostatic carcinoma cells: Perturbation of cell cycle progression and DNA fragmentation

1. 1.|We investigated the relationship between heat-induced perturbation of cell cycle progression and cytotoxicity at low temperature hyperthermia in three human cell lines human breast carcinoma cells (MCF-7) and human prostatic adenocarcinoma cells (DUT-145 and PC-3). 2. 2.|MCF-7 cells which were resistant to mild hyperthermia exhibited a G₁ block during heating at 41°C. In contrast, DUT-145 and PC-3 cells which were sensitive to mild hyperthermia failed to accumulate in G₁-phase. Both DUT-145 and PC-3 cells progressed through S-phase and accumulated in the G₂/M-phase. These results rule out any species-based generalization for heat sensitivity. 3. 3.|Electron micrographs and gel electrophoresis data show the accumulation of mitotic-like cells and DNA fragmentation during mild hyperthermia in prostatic carcinoma cells. 4. 4.|These results suggest that cell death is associated, at least partly with DNA fragmentation, perhaps apoptosis in prostatic carcinoma cells.