Autophagy inhibition by chloroquine sensitizes HT-29 colorectal cancer cells to concurrent chemoradiation

Figure 1 Radiation-induced autophagy. A: HT-29 cells were irradiated (8 Gy) and autophagy induction was assessed by the formation of double membrane autophagosomes on transmission electron microscopy 24 h post-treatment; B: Western blot analysis of LC3 expression demonstrates increased LC3-II:I ratio and autophagy induction at 4 and 6 h post-irradiation for HT-29 and HCT116 cells, respectively; C: Increased LC3II:I ratios are seen 24 h post-irradiation at 2-8 Gy for HT-29 cells; D: GFP-labeled LC3 puncta develop within 6 h of treatment with Rapamycin (200 nmol/L) or radiation (2-8 Gy) in both HCT116 and HT-29 cell lines. Bar graphs represent quantification of percentage of cells with perinuclear punctate pattern 6 h following radiation.