Figure 3
From: Inhibition of the hypoxia-inducible factor pathway by a G-quadruplex binding small molecule
CL67 inhibits colony formation and HIF-1α in a manner independent of VHL and the PI3K/AKT/mTOR and MAPK pathways.
(a) RCC4 cells (lacking VHL; RCC4) and RCC4 cells stably transfected with VHL (RCC4/VHL) were incubated for 4 h with the doses indicated of CL67 in normoxia (20% oxygen) or hypoxia (1% oxygen). Colony formation assays were then performed. Data represents the mean ±S.D. of 3 experiments with at least 2 replicates. *, Significant difference compared to untreated control (p < 0.01); **, Significant difference compared to both normoxic sample and untreated sample (p < 0.01). (b and c) RCC4 cells (pVHL −/−) and RCC4 cells stably transfected with pVHL were incubated with 5× IC50 doses of CL67 for the indicated times in normoxia or hypoxia. RCC4/VHL cells were exposed to hypoxia for 16 h to increase levels of HIF-1α before treating with CL67. Cells were lysed and Western blotting was performed probing for HIF-1α (b), HSP-90, Raf-1 and AKT (c). Actin or lamin A were used as loading controls. Data are representative of at least 2 independent experiments. Note that cropped blots are shown here.
