Fig 2: Different sensitivities of MM cell lines to pan PI3K and mTOR inhibitors. (A) Basal levels of PI3K isoforms a, β, γ, and δ in MM cell lines were detected by Western blotting, using isoform-specific antibodies. Tubulin was the loading control. Representative results from at least three independent experiments are shown. (B) Basal levels of AKT (S473 and T308), mTOR, PRAS40, S6, and 4E-BP1 phosphorylation, and panAKT and PTEN in MM cell lines were detected by Western blotting using specific antibodies. Tubulin was the loading control. Representative results from at least three independent experiments are shown. (C) MM cell lines were incubated for 5 days with the pan-class I PI3K inhibitor pictinisib. Viable cells were determined. Representative results from at least three independent experiments are shown. Error bars indicate standard deviations. (D) MM cell lines were incubated for 5 days with the mTOR inhibitor temsirolimus. Viable cells were determined. Representative results from at least three independent experiments are shown. Error bars indicate standard deviations.