Fig. 4: KLF5 suppresses HMOX1 transcription via ZEB1.

A The binding sites (−2000 to +100) of KLF5 in the HMOX1 promoter region predicted by the JASPAR matrix model. B ChIP assay showed that KLF5 could not occupy the binding sites of the HMOX1 promoter region. C Genecards predicted all potential transcription factors upstream of HMOX1 and Venn diagram showing that the transcription factors downstream of KLF5 intersected from genecards and KLF5-mediated TCGA-PAAD cohort and transcriptome sequencing. D mRNA level in human PDAC cells treated by control plasmid or shKLF5. E, F HMOX1 changes were measured in ZEB1-silenced CFPAC-1 and Capan-1 cells. G The binding sites (−2000 to +100) of ZEB1 in the HMOX1 promoter region predicted by the JASPAR matrix model. H ZEB1 upregulated HMOX1 promoter activity in HEK-293T cells in a dose-dependent manner. I To evaluate the activation of the HMOX1 promoter regulated by ZEB1, the ZEB1 plasmid and promoter constructs were co-transfected into HEK-293T cells for 24 h. The bar chart shows the promoter activities of site mutagenesis on predicted binding sites. The luciferase activity is shown as the fold activated by ZEB1 compared with the controls. J ZEB1 occupied the binding sites of the HMOX1 promoter region in CFPAC-1 and Capan-1 cells, as measured by ChIP assay. K, L Dual-luciferase reporter system was used to confirm the effect of ZEB1 on HMOX1 promoter activity in PDAC cells treated by shZEB1 or control plasmid.