NVP-BEZ235. Cell viability after treatment with different concentrations of NVP-BEZ235 was assessed by the MTS cell viability assay. MTS assay results are shown as ODU (mean±S.E.M.), which are linearly correlated with the cell number (R2=0·97) (A), and as the percentage of viable cells (mean±S.E.M.) compared with the control (B). (A) There was a dose- and time-dependent decrease in MPC cell viability after treatment with NVP-BEZ235. Treatment for 24, 48 and 72 h with 50 nM or higher concentrations of NVP-BEZ235 significantly decreased MPC cell viability compared with the control (MPC (24 h): ODU: control (n=8) vs 50 nM NVP-BEZ235 (n=8), *P≤0·05; control (n=8) vs ≥100 nM NVP-BEZ235 (n=8 for each condition), **P≤0·01; control (n=8) vs 1 μM NVP-BEZ235 (n=8), ***P≤0·001; MPC (48 and 72 h): ODU: control (n=8) vs ≥50 nM NVP-BEZ235 (n=8 for each condition), ***P≤0·001). (B) MPC cell viability curves for 48 and 72 h treatment with NVP-BEZ235 (n=8 for each condition). The x-axis shows the drug concentrations as log[M] : 48 h treatment with 1 and 10 μM NVP-BEZ235 decreased MPC cell viability by 96 and 100%, respectively, compared with the control (P≤0·001); 72 h treatment with 1 and 10 μM NVP-BEZ235 reduced MPC cell viability by 100% compared with the control (P≤0·001). (C) Phospho (p-) and total (t) protein expression of AKT, ERK and p70S6K after treatment with NVP-BEZ235 assessed by western blotting. The relative expression of each p-protein was calculated as the ratio of p-/t protein: 24 h treatment of MPC cells with 100 nM NVP-BEZ235 significantly diminished pAKT and pp70S6K levels but significantly increased pERK levels compared with the vehicle (ratio pAKT/tAKT: vehicle (n=6) vs 100 nM NVP-BEZ235 (n=6), **P≤0·01; ratio pERK/tERK: vehicle (n=6) vs 100 nM NVP-BEZ235 (n=6), *P≤0·05; ratio pp70S6K/tp70S6K: vehicle (n=3) vs 100 nM NVP-BEZ235 (n=3), *P≤0·05). (D) CgA expression assessed by western blotting. The relative expression of CgA was calculated as the ratio of CgA/β-actin: 24 h treatment of MPC cells with 100 nM NVP-BEZ235 significantly decreased the 50 kDa fragment of CgA compared with the vehicle (left panel, ratio CgA/β-actin: vehicle (n=3) vs 100 nM NVP-BEZ235 (n=3), *P≤0·05) while the 71 kDa fragment of CgA (right panel, ratio CgA/β-actin: vehicle (n=3) vs 100 nM NVP-BEZ235 (n=3), P=0·2) remained constant.