Figure 6

Hypoxia/HIF-1α-induced T-ALL cell invasion and MMP2/9 up-regulation require Notch1 signalling. (A) Representative 400× magnification fields in invasion assay of HIF-1α or Notch1 siRNA transfected cells exposed to hypoxia for 48 h. (B) The total number of migrated cells was counted manually. Results shown are expressed as a percentage of control invasion. *, P < 0.01. Data plotted are mean ± SD of three separate experiments. (C) qRT-PCR results show that inhibition of HIF-1α or Notch1 signalling attenuated the up-regulation of MMP2 and MMP9 observed during hypoxia. The results normalized to β-Actin are presented as relative expression level. *, P < 0.01. Data plotted are mean ± SD of three separate experiments. (D) Representative Western blot showing down-regulation of MMP2 and MMP9 expression by silencing HIF-1α or Notch1 in hypoxia.