Figure 1
Effect of CoCl2 and DFO treatment on HIF-1α expression. (A), normal breast epithelial cells MCF10A (B), estrogen receptor (ER) positive YS1.2 and (C,D), ER-negative pII breast cancer cells either untreated (control, open bars) or treated with CoCl2 or DFO (100 µM, hatched bars). HIF-1α was measured in the cell lysate by ELISA at times indicated as described in Methods. Histobars represent the mean ± SEM of 3 independent determinations. Asterisks denote significant difference from the control, with (*)p > 0.05, (**)p = 0.01, and (***)p = 0.001. Panel (E) Western blot analysis of HIF-1α in breast cancer cells, which were either untreated (control) or treated with CoCl2 or DFO (100 µM) and HIF-1α determined at the times indicated. Protein lysates were electrophoresed in 10% SDS-polyacrylamide gel and blotted onto nitrocellulose membrane which was then cut into narrow strips (in the region of expected bands) and individually probed with antisera to HIF1α (bands were detected at a molecular weight of 120 kDa which corresponds to the expected HIF1α size), or to β-actin, used as loading control.
