Figure 1From: NVP-BEZ235 and NVP-BGT226, dual phosphatidylinositol 3-kinase/mammalian target of rapamycin inhibitors, enhance tumor and endothelial cell radiosensitivityBGT226 and BEZ235 attenuate oncogenic signaling and reduce clonogenic survival after radiation. SQ20B cells were exposed to the indicated drugs for 1 h and evaluated by Western blotting for phosphorylation of mTOR (Ser2448), Akt (Ser-473) and S6 protein (ser-235/236). β-actin was used as a loading control. A, Dose response of the PI3K/mTOR pathway in SQ20B cells after 1 h exposure to the indicated drug. B, Time-course of PI3K/mTOR inhibition to indicated drugs at maximal effective doses. C-D, Response of PI3K/mTOR pathway 1 h after 4 Gy. Cells were treated with 5 nmol/L BGT226 (C) or 50 nmol/L BEZ235 (D) for 1 h before and 1 h after irradiation. E, Plating efficiency of SQ20B,T24 and FaDu cells after exposure to indicated drugs for 1 h before up to 17 h post-irradiation (n = 3). F, Clonogenic survival of indicated cell lines after 18 h treatment with BEZ235 (50 nmol/L) and BGT226 (5 nmol/L), as described in "Methods" (n = 3). P < 0.05; **, P < 0.01 over DMSO-treated control.Back to article page