Effect of microRNA-19b on proliferation, migration and invasion of pancreatic ductal adenocarcinoma

Abstract

Objective To examine the expression of microRNA (miRNA, miR)-19b in pancreatic ductal adenocarcinoma (PDAC) cell lines, and the functional role of miR-19b in proliferation, migration and invasion of PDAC cells. Methods Real-time quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR) was used to detect the expression level of miR-19b in human pancreatic ductal epithelial cell line (HPDE), human PDAC cell lines (PANC1, MiaPaCa2 and BxPC3) and huamn PDAC metastasis cell line (COLO357) and its fast-growing variant FG. The expression of miR-19b was inhibited or overexpressed in PDAC cell lines. Transwell assay and Matrigel assay were carried out to examine the migration and invasion capabities of PDAC cells with miR-19b silencing or overexpressing. Methyl thiazol tetrazolium (MTT) and colony formation assays were performed on PDAC cell lines with miR-19b silencing or overexpression. Western blotting was used to detect the expression of proliferation markers (p21 and p27) in PDAC cell lines after miR-19b was silenced or overexpressed. Results The results of RT-qPCR showed the expression level of miR-19b in human PDAC cell lines PANC1, MiaPaCa2, BxPC3 and metastatic cell line COLO357 and FG (198.45±21.22, 221.37±18.59, 182.51±13.48, 317.64±15.20, 331.34±17.18) was significantly higher than that in normal human pancreatic ductal HPDE (98.21±14.54, P<0.05). Transwell cell migration assay and Matrigel cell invasion assay showed that the migration and invasion ability of FG cells after miR-19b silencing [(22.54±2.87)%, (28.87±5.62)%] was significantly decreased as compared with the control group [(99.65±3.07)%, (98.73±4.38)%, P<0.01]. In contrast, the migration and invasion ability of BxPC3 cells overexpressing miR-19b [(317.53±10.21)%, (286.77±12.83)%] was significantly higher than that of the control group [(97.89±5.31)%, (98.25±7.57)%, P<0.01]. The colony formation and MTT assays showed that the proliferation ability of PDAC cells after miR-19b was silenced was significantly decreased as compared with the control group (P<0.01). The result of Western blotting showed that the expression of proliferation markers (p21 and p27) in PDAC was increased by (3.25±0.27) and (5.38±0.33) times respectively as compared with the control group after miR-19b silencing (P<0.01). When miR-19b was overexpressed, the expression of p21 and p27 decreased by (2.68±0.15) and (3.27±0.27) times respectively as compared with the control group (P<0.01). Conclusion MiR-19b could promote the migration and invasion of PDAC cells and increase the proliferation capability. Key words: Pancreatic carcinoma; MicroRNA-19b; Metastsis; Proliferation