PTEN deficiency enhances the proliferative and survival signals of MCs. (A) Cells (5 × 105 cells) were stimulated with IgE/Ag, SCF, or IL-3 and lysed in RIPA buffer. Phosphorylated Akt was probed with anti–phosho-Akt (T308). Total Akt was used as the loading control. (B) IL-3 or SCF-mediated phosphorylation of STAT5 was determined by immunoblot. Stimulated cells (5 × 105 cells) were lysed in RIPA buffer, and phosphorylated STAT5 was detected with an antibody recognizing phosphorylated STAT5. One representative of 4 experiments is shown. (C) BMMCs (5 × 105 cells) incubated in the absence of cytokines for 3 hours and restimulated with SCF, IL-3, or SCF and IL-3 for 24 hours. Expression of antiapoptotic factors (Bcl-2 and Bcl-XL) was measured after 24 hours by immunoblotting with antibodies to Bcl-2 or Bcl-XL. β-actin was used as loading control. (A-C) One representative of a minimum of 4 experiments is shown. Fold induction reflects the mean of all experiments normalized to WT control (0 time; A-B) or to WT control with no treatment (C).