Fig. 3
From: Acidic tumor microenvironment abrogates the efficacy of mTORC1 inhibitors
Reversible inhibition of mTORC1 by acidic pH. a HT29 cells were cultured for 3 h in medium buffered at the indicated pH values. Cells were subsequently lysed and Western blot analysis was performed with the indicated antibodies. b HT29 cells were exposed to medium buffered at pH 6.4 for the indicated time periods. Cell lysates were prepared and analyzed by Western blot for phospho S6 ribosomal protein and actin expression. c HT29 cells were cultured at pH 6.4 for 3 h followed by restoration of pH to 7.4 for the indicated time periods. Subsequently, cell lysates were prepared and analyzed by Western blot. d Western blot analysis of lysates prepared from HT29 cells treated for 3 h with rapamycin (100 nM) or DMSO as a control (left panel), HT29 cells exposed for 3 h to medium buffered to pH 7.4 or 6.4 (middle panel), or HT29 cells expressing a control or a raptor shRNA (right panel)