Fig. 4.

PTEN-deficient cells require PIK3CB for growth. Dox = doxycycline. (A) Stable control or PIK3CA shRNA–containing HCT116 cells were transfected with either control or PTEN siRNA. Cells grown in the absence or presence of doxycycline were harvested for Western blot analysis after 72 h of treatment. (B) BT549, PC3, and U87MG cells stably transduced with either scramble control or PIK3CB were grown in the presence or absence of doxycycline for 72 h. PIK3CB transcript levels were assessed at the end of treatment by Taqman RT-PCR. (C) Described cells were cultured in a 6-well dish in the presence or absence of doxycycline (10 ng/ml) for 14 days. The effects of PIK3CB silencing on foci formation were visualized by crystal violet staining.