Figure 8

Notch1 signalling is required for hypoxia/HIF-1α-mediated T-ALL chemoresistance. (A) HIF-1α- or Notch1 siRNA-transfected cells were subjected to Annexin V/PI staining and flow cytometry after treatment with 1 μM dexamethasone under hypoxic conditions for 48 h. (B) Percent of total apoptotic cells by quantitative analysis. *, P < 0.01. Down-regulation of HIF-1α or Notch1 effectively impaired cell viability in hypoxia, with an increased proportion of apoptosis induced by dexamethasone. (C) Western blot analyses of apoptosis-related proteins with cell lysates under the same conditions. Results shown are representative of at least three independent experiments.