Fig. 5
PIK3R1 loss increases cellular PIP3 level by decreasing PTEN protein stability and enhancing p110α activity. a Lipids of transfected SKOV3 and OAW28 cells were collected and subjected to lipid detection. PIP3 level in each sample was normalized to that of PIP2. b Protein lysates were subjected to western blotting. Band intensities of blots from three independent experiments were quantified and normalized to that of mock. Mean values of relative PTEN levels with SD are shown. c siRNA-transfected SKOV3 cells were incubated with 50 μM Cycloheximide (CHX) for indicated hours before western blotting. Band intensities were normalized to 0 h time point and mean values with SD are shown. d p110α and p110β proteins were immunoprecipitated and subjected to PI3-kinase activity assay. Values were normalized to corresponding p110α and p110β protein levels. e p110α protein was immunoprecipitated in OAW28 cells transfected with PIK3R1 siRNA prior to western blotting. The numbers below the blots represent the mean values from densitometry readings of three independent experiments. Error bars represent SD. *p < 0.05; **p < 0.005; ***p < 0.001; ns, no significant difference compared with mock using t-test
