Figure 1.

HIF-1α knockdown results in G₁ accumulation and p21 induction in U2OS cells. (A) Confirmation of HIF-1α knockdown using U2OS whole cell lysates (WCL) for western blot analysis. Samples were harvested following siRNA protocol and 2 h of DFX treatment. (B) U2OS cells were transfected with nontargeted or HIF-1α siRNA oligonucleotides prior to harvesting for cell cycle analysis using the propidium iodide staining protocol. Student's t-tests (two tailed) were performed and p-values calculated. *p ≤ 0.05 and **p ≤ 0.01. (C and D) U2OS cells were transfected using nontargeted or HIF-1α siRNA prior to harvest of WCL. Samples were analyzed by western blot using the specific antibodies indicated. (E) U2OS cells were transfected as in (B) and mRNA extracted. HIF-1α, p21, p27 and GLUT3 mRNA were analyzed using quantitative PCR. Graphs depict HIF-1α, p21, p27 and GLUT3 mRNA normalized to actin mRNA and compared to untreated samples. Student t-tests (two tailed) were performed and p-values calculated. *p ≤ 0.05 and **p ≤ 0.01. Data refers to a minimum of three independent experiments.