Fig. 6

STAT3 is regulated via circ_MAPK9/miR-642b-3p axis in HCC. A, Schematic representation of the binding sites between miR-642b-3p and STAT3 3’UTR. Comparison of the luciferase activity of WT or MUT STAT3 3’UTR after treatment with miR-642b-3p mimics in HEK293T cells. B and C, The expression of STAT3 mRNA and protein in SMMC-7721 and SK-Hep1 cells transfected with miR-642b-3p mimics analyzed by qRT-PCR and Western blot. D, The expression of STAT3 and p-STAT3 protein in HCC cells transfected with circ_MAPK9 siRNA analyzed by Western blot. E, The STAT3 and p-STAT3 protein expression after transfection with circ_MAPK9 siRNA and/or miR-642b-3p inhibitor in HCC cells, analyzed by Western blot. F, The STAT3 and p-STAT3 protein expression after transfection with circ_MAPK9 siRNA and/or STAT3 plasmid in HCC cells, analyzed by Western blot. G, The proliferative capacity of SMMC-7721 and SK-Hep1 cells after transfection with circ_MAPK9 siRNA and/or STAT3 plasmid detected by colony formation assay. H, The STAT3 and p-STAT3 protein expression in circ_MAPK9 knockdown SMMC-7721 cells treated with IL-6, analyzed by Western blot. I, The proliferative capacity of circ_MAPK9 knockdown SMMC-7721 cells treated with IL-6 detected by EdU assay