R. Vanderwaal et al., A COMPARISON OF THE MODES AND KINETICS OF HEAT-INDUCED CELL-KILLING IN HELA AND L5178Y CELLS, Radiation research, 148(5), 1997, pp. 455-462
The mode and kinetics of cell killing in HeLa and L5178Y cells were in
vestigated to elucidate possible relationships between the mechanisms
and modes of heat-induced cell death. L5178Y cells were heat-shocked f
or either 24 min at 43 degrees C or 30 min at 45 degrees C, while HeLa
cells were given only the latter treatment. The degree of heat-induce
d excess nuclear protein correlated with cell death in HeLa cells but
not in L5178Y cells. This difference suggests that the mechanism of ce
ll death differs between these cell lines. With L5178Y cells the main
mode of death after treatment at 43 degrees C was apoptosis with littl
e progression of cells through the cell cycle. However, after treatmen
t at 45 degrees C these cells died by necrosis without progressing thr
ough the cell cycle. HeLa cells were found to die by a mechanism other
than apoptosis after significant progression of cells through the cel
l cycle and perturbation of the normal distribution of cells in the ph
ases of the cell cycle (specifically, the fraction of cells in S and G
(2) phase increased 50% and 30%, respectively, prior to the occurrence
of measurable cell death). These results are consistent with the hypo
thesis that the response to injury which has the potential to be letha
l varies between different cell types, and results in the induction of
different pathways leading to cell death. (C) 1997 by Radiation Resea
rch Society.