Figure 4

Aloperine activates caspase-9 via downregulation of p-PTEN. (A) U266 and MM.1S cells were treated with aloperine (80 μM), IL-6 (10 ng/ml), or both for the indicated times. The expression levels of p-PTEN and p-AKT were determined using Western blotting. (B) U266 cells were transiently transfected with siRNA against PTEN or non-targeting control siRNA and then treated with 80 μM aloperine for 48 h prior to evaluating the expression of caspase-9, p-PTEN, p-AKT, and β-actin by Western blotting. (C) Transfected cells were treated with 80 or 160 μM aloperine for 48 h, and apoptosis was determined via FACS analysis of DNA fragmentation of propidium iodide-stained nuclei. Background apoptosis: si-control, 2.3%; PTEN siRNA, 2.6%. Data represent the mean ± SD of three independent experiments carried out in triplicate; ^a P < 0.001. GAPDH was assessed by Western blotting. All protein levels were quantified densitometrically and normalized to GAPDH.