Methylation of the miR-29b-3p promoter contributes to angiogenesis, invasion, and migration in pancreatic cancer

The aim of the present study was to investigate the effects of microRNA (miR)-29b-3p gene promoter methylation on angiogenesis, invasion, and migration in human pancreatic cancer. Prediction of promoter methylation of miR-29b-3p was performed through the MethPrimer tool. Then the methylation levels of miR-29b-3p in human pancreatic cancer tissues and cell lines were detected by pyrosequencing, and the relative expression of miR-29b-3p was assessed in pancreatic cancer tissues by qPCR. The results were analyzed by linear regression. Western blot analysis was used to detect expression of DNA methyltransferases (DNMTs) in pancreatic cancer tissues and adjacent tissues. The Transwell assay was used to detect the ability of cell migration and invasion. Cells were co-cultured with human umbilical vein endothelial cells (HUVECs) to detect the ability of angiogenesis. The results revealed that DNMT1 expression in pancreatic cancer tissues was higher than that in adjacent tissues. Further results showed that expression of miR-29b was negatively correlated with the methylation level of the miR-29b promoter. Bxpc3 and Capan-2 cells had higher methylation levels, and the expression level of miR-29b-3p in Bxpc3 and Capan-2 cells was found to be lower than that of other cell lines. Expression of zonula occludens-1 (ZO-1) and occludin was significantly increased, and the migration of cancer cells was decreased after cells were treated with siRNA DNMT1. Further results showed that miR-29b reversed the promotive effect of DNMT1 overexpression on tumor cell malignant properties. Methylation of the miR-29b-3p promoter contributes to angiogenesis, invasion, and migration in pancreatic cancer. This study indicated that the alteration of methylation of mR-19b may be a potential approach for inhibiting the progression of pancreatic cancer.