Figure 1.

Modulation of cell growth and activation of HIF signaling in response to hypoxia in a series of luminal and basal A cell lines. (A) Cell growth analyzed by SRB for three luminal (MCF7, T47D and BT474) and three basal A (SUM149PT, HCC1806 and HCC1143) breast cancer cell lines grown under normoxia (21% O₂; NX) or hypoxia (1% O₂; HX) for 1, 3 or 5 days. Mean and SD of OD values from three biological replicates performed in triplicate are shown. ns, non-significant; *, p < 0.05; **, p < 0.01; ***, p < 0.001; ****, p < 0.0001, ns, not significant. (B) Luminal and basal A cell lines incubated under normoxia or hypoxia for 3 days analyzed for HIF1α expression and localization by confocal immunofluorescence microscopy. Blue, Hoechst; Green, HIF1α Ab. One representative experiment of three biological replicates is shown. (C) CA9 expression analyzed by Western blot after 3 and 5−day incubation under normoxia or hypoxia for the indicated luminal and basal A cell lines. (D) Identification of known HIF1 responsive genes [31] in TempO-Seq data comparing 5−day incubation under normoxia or hypoxia in MCF7 and HCC1143 cells. Mean Log₂foldchange for hypoxia relative to normoxia and SD of triplicate measurements is shown. **, padj < 0.01; ***, padj < 0.001; ****, padj < 0.0001.