Hypoxia induces the expression of HIF-1α and GPER in CAFs. (a-d) The exposure to 100 μM CoCl2 (a, c) or low oxygen tension (2% O2 for 3 h) (b, d) up-regulate the mRNA (a, b) and protein (c, d) expression of HIF-1α and GPER as evaluated by real-time PCR and immunoblotting, respectively. In RNA experiments, values are normalized to the 18S expression and shown as fold changes of mRNA expression induced by CoCl2 compared to cells treated with vehicle. (e) The up-regulation of GPER observed treating CAFs for 6 h with 100 μM CoCl2 is abrogated by silencing HIF-1α. Each data point represents the mean ± SD of three independent experiments. Side panel shows densitometric analysis of the blots normalized to β-actin. (○), (●) P < 0.05 for cells receiving vehicle (-) or cells cultured under normoxia versus CoCl2 treatment or cells cultured under hypoxia.