Abstract: ObjectiveTo study the epigenetic regulation of pancreatic carcinoma related microRNA (miR34a, miR34b, miR148a and miR203a) expression by gene promoter methylation, and its effect on the proliferation, migration and invasion of pancreatic carcinoma cells. MethodsThe pancreatic carcinoma cells were divided into two groups: control group and treatment group. Control group was treated with 0 μmol/L DNA methyltransferase inhibitor 5-Aza-CdR and treatment group was treated with 60 μmol/L 5-Aza-CdR. The methylation status of microRNA gene promoter regions was detected by MSP (methylation-specific PCR). The microRNAs’ expression levels were evaluated by real-time PCR. The CCK-8 assay, wound healing assay and Transwell assay were employed to study the proliferation, migration and invasion of pancreatic carcinoma cells, respectively. ResultsThe results of MSP showed that the methylated band of the treated group was weaker than that of the untreated group and the unmethylated band of the treated group was stronger than that of the untreated group. Real-time PCR results showed that the relative expression levels of microRNAs in the treatment group were higher than those in the control group ( P<0.05). The CCK-8 assay showed that inhibition rate of the treatment group showed dose-dependent effect with the increase of drug concentration. Wound healing assay showed that the wound healing rate of Treatment group was lower than that of untreated group ( P<0.01). The results of transwell assay showed that the number of migrated cells in the treated group was less than that in the untreated group ( P<0.01). ConclusionDecreased methylation levels in microRNA promoter region caused by 5-Aza-CdR treatment increased the expression of miR34a, miR34b , miR148a and miR203a, leading to inhibition of the proliferation, migration and invasion of pancreatic carcinoma cells.