PI3K signaling responses to PI3K pathway inhibition.

<p>(A) Knock-in cells (H1047R A) were cultured with inhibitors at concentrations used in the 3-D culture assay and analyzed by Western blotting for indicated treatment times. (B) PIP₃ levels assessed at 48 hours post treatment with 3-D culture concentrations of inhibitors in the knock-in clone (H1047R A). (C) PI3K and Akt inhibitor effects can be distinguished in 3-D culture through variations in cellular morphology. Phase contrast images of the knock-in clone (H1047R A) show representative phenotypes of treatment with 0.5 µM GDC-0941, 5 µM AKT1/2i, or the same compound doses in combination after 2 days in culture.