Figure 3. miR-29b reduces CDKN2B promoter methylation and increases CDKN2B expression by directly targeting DNMT3B. Effect of miR-29b overexpression on CDKN2B mRNA (A) and protein (B) levels in QBC939 cells. (C) MSP analysis of CDKN2B gene promoter methylation changes in QBC939 cells transfected with LV-miR-29b or LV-miR-NC. (D) Schematic representation of the putative miR-29b binding site in the DNMT3B 3’UTR. (E, F) Effect of miR-29b overexpression on DNMT3B mRNA (E) and protein (F) levels. (G) Dual-luciferase reporter assay results showing reduced WT-DNMT3B promoter-driven luciferase activity in QBC939 cells transfected with miR-29b mimics. (H) Relative expression of DNMT3B protein in QBC939 cells. (I) Relative expression of DNMT3B mRNA in clinical cholangiocarcinoma specimens. (J) Pearson correlation analysis between miR-29b and DNMT3B expression in cholangiocarcinoma specimens. The values presented are means ± SD. *P<0.05 compared to the negative control group, as determined by analysis of one-way variance (ANOVA), followed by the repeated measures.