Identification of known cell death–related genes in autophagy regulation in l(2)mbn cells using RNAi. (A) The percentage of LTG^high cells was reduced by hid-RNAi (P = 0.006) but not by rpr, grim, and skl-RNAi. (B) Knockdown of Ras, phl, and rl expression by RNAi resulted in an increase in the percentage of LTG^high cells. (Ras, P = 0.003; phl, P = 0.001; and rl, P = 0.028). (C) th-RNAi treatment (24 h) had no significant effect on LTG levels; in contrast, RNAi of Bruce resulted in an increase in LTG fluorescence levels (P = 0.01). (D) Reduction of debcl, Buffy, or p53 expression by RNAi resulted in a decrease in LTG fluorescence levels. (debcl, P = 0.018; Buffy, P = 0.006; and p53, P = 0.004). (E) RNAi of effector caspase Dcp-1 resulted in a significant decrease in the LTG^high population (P = 0.001). (F) Representative images of GFP-LC3 puncta in cells treated with the indicated RNAi after a 2-h starvation treatment. Bar, 10 μm. (G) Quantification of cells with GFP-LC3 puncta after RNAi treatment. Cells with more than three GFP-LC3 punctate dots were considered to be GFP-LC3–positive cells. Cells treated with the RNAi indicated here all showed a significant difference (P < 0.05) in the percentage of GFP-LC3–positive cells compared with the human (Hs) RNAi control. (Pten, P = 0.006; Tor, P = 0.034; Buffy, P = 0.005; debcl, P = 0.003; Bruce, P = 0.003; Dcp-1, P = 0.007; hid, P = 0.002; Ras, P = 0.006; and phl, P = 0.050). Results represent the mean value ± SD from three independent experiments.