Skip to main content
. Author manuscript; available in PMC: 2013 Aug 8.
Published in final edited form as: Cancer Res. 2008 Jan 15;68(2):352–357. doi: 10.1158/0008-5472.CAN-07-2069

Figure 4. Activation of autophagy by ARF in U2-OS cells is p53-dependent.

Figure 4

A, NARF cells transfected with p53 siRNA and induced with IPTG accumulate significantly fewer GFP-LC3 puncta compared with NARF cells transfected with control siRNA. Cells were transfected with siRNA, infected with adenovirus expressing GFP-LC3, induced with IPTG, and observed under a fluorescence microscope. B, quantitation of the percentage of cells with GFP-LC3 puncta after transfection with control or p53 siRNA. C, induction of p14ARF in NARF cells transfected with control siRNA causes a significant increase in p53 level and in the level of the p53 targets MDM2, p21, and PUMA, as detected by Western blot. The increase in the level of LC3-II is indicative of the activation of autophagy in these cells. In cells transfected with p53 siRNA, the level of p53 and of the p53 targets is undetectable, and there is no significant increase of LC3-II level.