Fig. 4. S6K1 is critical for the survival of 661W cone cells in vitro.

a Western blotting analysis and densitometry of S6K1 protein expressions in 661W cone cells after PTEN overexpression. Results are presented as the mean±SD (n = 4). b S6K1 knockdown by a specific shRNA against p70S6K1 resulted a higher number of TUNEL-positive 661W cone cells compared with control scramble groups. c 661W cone cells were transfected with specific shRNAs against 4EBP1, elF4E, or scramble controls. When compared with scrambled shRNA groups, knockdown of either 4EBP1 or elF4E expression did not affect the survival of 661W cone cells. d S6K1 overexpression rescued 661W cone cells in the presence of PTEN. Results are expressed as the ratio of TUNEL-positive cells to DAPI-stained nuclei. Values represent means±SDs (n = 4). ns, not significant, *p < 0.05; **p < 0.01