[Retracted] Activating IL-6/STAT3 Enhances Protein Stability of Proteasome 20S α+β in Colorectal Cancer by miR-1254

Figure 6

STAT3 could inactivate the transcription of miR-1254 (a). The classic STAT3-binding motif (JASPAR Database) and two putative STAT3 responsive elements (E1 and E2) in the miR-1254 promoter region are depicted in a schematic diagram. TSS refers to miR-1254’s transcriptional start point. (b) HCT116 cells were treated with STAT3 inhibitor AG490 at a concentration of 20 μM. The expressions of pSTAT3 were analyzed by western blot. (c) HCT116 cells were treated with IL-6 or AG490. miR-1254 mRNA levels were analyzed by RT-PCR. (d) When the cells were transfected with STAT3 plasmids, the luciferase assay was employed to determine miR-1254 promoter transcriptional activity. (e) miR-1254 promoter activity when cells were treated with AG490. (f) Two putative STAT3-binding sites in the miR-1254 promoter were removed, labeled E1-Del and E2-Del. When STAT3 expression was driven in HCT116 cells, the transcriptional activity of the two miR-1254 promoter deletion mutants was assessed through luciferase assay. (g) ChIP experiments revealed that STAT3 is linked to the miR-1254 promoter’s E1 element. As a negative control, IgG was used. , , and .

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