Autophagy in irradiated Caspase 3/7 DKO MEFs and effects on radiosensitivity.

<p>(A) GFP-LC3-transfected WT or Caspase 3/7 DKO MEF cells were treated with and without 5 Gy and then examined by fluorescence microscopy after 24 h. The percentage of cells with punctate GFP-LC3 fluorescence was calculated relative to all GFP-positive cells. Error bars are shown as mean S.D. (B) LC-I and –II expression was determined by Western blot using lysates from WT and Caspase 3/7 DKO MEF cells treated with 0 or 5 Gy after 24, 48 h. Actin was probed to demonstrate equal loading. (C) Also shown are immunoblots of phospho-Akt and p-S6 using the lysates from WT and Caspase 3/7 DKO MEF cells treated with 0 or 5 Gy after 30 min. (D) WT and Caspase 3/7 DKO MEF cells were transfected with either control siRNA or 25 nM siRNAs directed against ATG5 and Beclin-1 or (E) transfected with vector or ATG5 and Beclin-1 cDNA containing plasmids. They were then irradiated with 0 to 6 Gy. After 8 days, colonies were stained and scored. Values shown are the mean±S.D. of three separate repeated experiments.