siRNA-mediated knock-down of HIF-1α expression leads to the suppression of three key glycolysis genes. Expression of three key genes in the glycosis pathway, GLUT1, HK1, and PGK1 was monitored by real-time RT-PCR. Cells were transfected with HIF-1α siRNA EGFP-pSUPER vector, scrambled HIF-1α control siRNA, or an expression plasmid encoding HIF-1α. After 20 h, transfected cells were exposed to hypoxia for 24 h (n = 5 in each group). $, P < 0.05 compared to normoxic control; #, P < 0.05 compared to normoxic and hypoxic HIF-1α siRNA; *, P < 0.05 compared to hypoxic mock-transfected and scrambled HIF-1α control siRNA transfection. siRNA: HIF-1α siRNA vector transfected, Mock: mock transfected, HIF: HIF-1α expression plasmid transfected.