Figure 4. HBXIP increases the protein level of HIF1α through blocking the degradation of HIF1α to activate miR-183/96/182.

A. The interaction of HIF1α with HBXIP was examined by co-IP assays in 293T cells, followed by Western blot analysis. B. The interaction of HIF1α with the promoter region of miR-183/96/182 cluster was examined by ChIP assays in MCF-7 cells. C. In ChIP assays, the expression of HBXIP and HIF1α was validated by Western blot analysis. D. The expression of HIF1α and HBXIP in MCF-7 cells treated with 25 mM MG-132 was examined by Western blot analysis. E. The expression of HIF1α and HBXIP in MCF-7 cells treated with 100 mg/mL cycloheximide (CHX) was examined by Western blot analysis. F. The ubiquitination levels of HIF1α were measured by Western blot analysis in MCF-7 cells. G. The interaction of HIF1α with pVHL was examined by co-IP assays in MCF-7 cells, followed by Western blot analysis. Each experiment was repeated at least three times.