Figure 2

Real-time RT-PCR and Western blot for Sp1, ADAM17 and HIF-1α in U87. N: normoxic incubation, H: hypoxic incubation, the 8 thru 20 hours indicate time points of hypoxic incubation. Sp1-DR: stable U87 cells expressing Sp1 siRNA. A. RT-PCR of U87 cells subjected to normoxic and hypoxic incubation for 8, 12, 16 and 20 hours. ADAM17, Sp1 and HIF-1α mRNA levels significantly increase under hypoxic conditions, peaking at 12 hr incubation.*P < 0.05 compared to normoxic control. B. U87 cells harvested for Western blot were incubated under normoxic and hypoxic conditions. ADAM17, Sp1 and HIF-1α proteins increased under hypoxic conditions, peaking after 12 hr hypoxic incubation. C. RT-PCR after 12 hour hypoxic incubation of U87 control and Sp1-deficient U87 cells. Sp1 down-regulation significantly decreased mRNA levels of Sp1, ADAM17 and HIF-1 α. *P < 0.05 compared to normoxic control. #P < 0.05 compared to hypoxic control. D. Western blots after 12 hour hypoxic incubation of U87 control and Sp1-deficient U87 cells. Lanes 1 and 2: U87 control. Lanes 3 and 4: Sp1-deficient U87 cells. ADAM17, Sp1 and HIF-1α decreased compared to the control under hypoxic conditions.