Research Paper Volume 5, Issue 12 pp 884—901
eIF2α phosphorylation bypasses premature senescence caused by oxidative stress and pro-oxidant antitumor therapies
Figure 7. Deficiency of eIF2αP sensitizes human tumor cells to pro-oxidant effects of doxorubicin.
(A) HT1080 WT and KI cells were treated with 30 nM doxorubicin (Dox) for 36 hours. Untreated as well as doxorubicin treated cells were subjected to staining for SA-β-Gal. Average values of the percentages of SA-β-Gal positive cells from three independent experiments are shown in the histograms. (B) Protein extracts (50 μg) from untreated or doxorubicin (30 nM) treated WT and KI cells were immunoblotted for indicated proteins. HA-eIF2αS51A in KI cells (lanes 3,4) migrates slower compared to endogenous eIF2α in WT cells (lanes 1,2). (C) Endogenous ROS levels in HT1080 cells WT and KI treated with 30 nM doxorubicin were measured by CellRox fluorescence. Histograms represent the average ROS levels from three independent experiments.