Constitutively active Akt1 partially rescues MCF-7 cells from apoptosis induced by MP1 gene silencing. (A) Immunoblot of p-Akt and Flag in stable pools of MCF-7 cells infected with control (pBabe-puro) or Myr-Flag-Akt1 expression vector as described in Materials and Methods. (B) The stable pools of cells described in (A) were transfected with 30 nM control siRNA or MP1 siRNA for 48 h, and cell viability was determined by trypan blue exclusion assay. Bars represent the percentage of trypan blue-positive cells. Error bars represent the mean ± SD for three independent experiments, *p < 0.05. (C) Immunoblot of PARP, ER and MP1 in a representative experiment described in (B).