Figure 1.

Extracellular ATP regulates hypoxia‐inducible factor (HIF) signaling in breast cancer cells. A, Transwell invasion assays demonstrated that ATP enhanced invasion ability of breast cancer cells. B, MCF‐7 cells treated with/without 100 μmol/L ATP for 24 h were analyzed by cDNA microarray. KEGG pathway analysis showed that ATP significantly affected HIF signaling. C, Heatmaps showed alterations of HIF signaling‐related genes. D, Quantitative PCR demonstrated that most HIF signaling‐associated genes were upregulated via 24 h ATP treatment. E‐G, Western blotting illustrated alterations of HIF‐1/2α in different hours of ATP treatment (E), different concentrations of ATP treatment (F) and in different cells (G). H, Immunofluorescence showed that ATP increased HIF‐1/2α level. Error bars represent means ± SD from triplicates. *P < 0.05; **P < 0.01; ns, not significant