Fig. 7. SOX12 is identified as a direct target gene of HIF-1α.

a, b CRC cells were cultured under hypoxic (0.5% O₂) conditions for the indicated time intervals and SOX12 expression was examined using qRT-PCR (a) and western blotting (b, c). A luciferase reporter construct carrying the (−1526/ + 150) SOX12 promoter was transfected into the indicated CRC cells, and luciferase activity was measured after 24 h. (d) SW480 cells and SW620 cells were separately infected with HIF-1α lentivirus (LV-HIF-1α) and shHIF-1α lentivirus (LV-shHIF-1α). SOX12 transcription and expression levels were measured after 24 h using luciferase assays (left panel), qRT-PCR (middle panel) and western blotting (right panel). (e) Truncated and mutated SOX12 promoter constructs were cotransfected with pCMV-HIF-1α, and the relative luciferase activity was confirmed. (f) A ChIP assay confirmed the direct binding of HIF-1α to the SOX12 promoter in CRC cells and human CRC tissues. *P < 0.05, **P < 0.01 compared with the control. The data are presented as the mean ± s.d