Constitutively activated STAT3 promotes survival and proliferation of MO7e cells.
(A) Left panel: MO7e cells were transduced with either empty pLNCX vector or vector containing the wild-type STAT3-FLAG or STAT3-C–FLAG. After stable lines of cells were obtained by selection in G418 (0.8 mg/mL), total cellular lysates were prepared and subjected to Western blot analysis with an anti-FLAG antibody (arrow). Right panel: Cytosolic extracts from MO7e cells, in the presence or absence of SCF, were incubated with 32P-labeled SIEm67 probe, followed by EMSA. Some samples were preincubated with an antibody against FLAG before incubation with labeled probe. (B) MO7e cells transduced with the empty vector, wild-type STAT3, or STAT3-C were cultured in the presence or absence of different concentrations of rhSCF for 24 hours. Apoptosis (left panel) and DNA synthesis (right panel) were determined by acridine orange staining and 3H-thymidine incorporation, respectively. The results are presented as a mean ± SE from 3 independent experiments.
