P-Y-Stat5 interacts with PI3-kinase in HMC-1 cells. (A) Stat5 (left panel) or p85 (right panel) was immunoprecipitated from HMC-1 cell extracts with specific or isotype control antibodies. The presence of p85 (left panel) or Stat5 (right panel) in the immunoprecipitates was detected by Western blot. (B) HMC-1 cells were also transduced with 100 nM TAT-wtAkt or TAT-dnAkt for 9 days and the number of living cells was determined every 3 days using the trypan blue dye assay. Results are the mean of 3 independent experiments. (C) Lysates from transduced HMC-1 cells were analyzed by Western blotting using anti–HA and anti–Akt antibodies. (D) HMC-1 cells were transduced or not (NaCl) with the TAT-wtStat5, TAT-dnStat5, TAT-wtAkt, and TAT-dnAkt fusion proteins or a mixture of TAT-wtStat5/TAT-wtAkt or TAT-dnStat5/TAT-dnAkt proteins (ratio 1:1) for 3 days. Cell growth was determined using the trypan blue dye assay. (E) Extracts from HMC-1 cells, either untreated (NaCl) or transduced with TAT-cS5^F and TAT-dnStat5 recombinant proteins for 6 days, were analyzed by Western blot with anti–P-S-Akt and anti–Akt antibodies. Representatives of 3 independent experiments are shown.