Fig. 3

ER-α is post-transcriptionally regulated by hypoxia. a ESR1 mRNA levels were compared between normoxic conditions (black columns) and hypoxia treatment (1% O₂, 24 h) (gray columns) in a panel of ten ER-positive cell lines (Change in ESR1 mRNA levels: p = 0.56 LY2, p = 0.24 MCF7, p = 0.48 BT474, p = 0.31 T47D, p = 0.82 ZR75B, p = 0.07 CAMA-1, *p = 0.04 MPE600, p = 0.55 MDA-MB-175, *p = 0.03 MDA-MB-361, p = 0.18 HCC1428). Levels were normalized to TBP. Data are represented as mean ± SEM (from duplicate experiments). b Representative western blot of MDA-MB-231 wild-type cells at normoxia or MDA-MB-231 overexpressing ER-α at normoxia and hypoxia (1% O₂, 24 h) for HIF-1α, ER-α and β-actin. c Representative western blot of phospho-p70-S6K, phospho-4EBP1 and β-actin protein from MCF7, BT474, T47D, ZR75B at normoxia or hypoxia (1% O₂, 24 h). d Representative western blot of MCF7, BT474, T47D and ZR75B at normoxic or hypoxic conditions (1% O₂, 16 h) untreated or treated with MG132 (10 mM, 16 h) for HIF-1α, ER-α and β-actin