Function of microRNA-15b in proliferation, migration and apoptosis of pancreatic cancer cells

Objective To observe the expression of microRNA (miRNA, miR)-15b in pancreatic cancer (PC) cells and its effect on proliferation, migration and apoptosis of pancreatic cancer cell lines. Methods Real-time quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR) was used to detect miR-15b expression in four pancreatic cancer cell lines (SW1990, CFPAC-1, PANC-1, BxPC-3) and human normal pancreatic ductal epithelial cell line (HPDE6c7). CFPAC-1 and PANC-1 cells stably transfected with miR-15b short hairpin RNA (shRNA) were used as experimental group, and CFPAC-1 and PANC-1 cells which normally expressed miR-15b were transfected with negative control (NC) as control group. The proliferation of CFPAC-1 and PANC-1 cells was measured by cell counting kit-8 (CCK-8) proliferation assay after transfection. The migration ability of CFPAC-1 and PANC-1 cells was measured by Transwell migration assay. The apoptosis of CFPAC-1 and PANC-1 cells was examined by flow cytometry. Results The expression levels of miR-15b in 4 pancreatic cancer cell lines (SW1990, CFPAC-1, PANC-1, BxPC-3) were 3.63±1.02, 5.28±0.76, 6.72±1.39 and 4.68±1.56 respectively, which were significantly higher than that (1.08±0.23) in HPDE6c7 cells (t=9.944, 10.326, 12.013, 15.877, P<0.01). The cell proliferation ability of CFPAC-1 cells in miR-15b low expression group at 2, 3 and 4 d (0.51±0.04, 0.94±0.06, 1.25±0.15) was significantly reduced correspondingly as compared with that of CFPAC-1 cells in control group (0.68±0.06, 1.21±0.09, 1.95±0.12) (t=8.256, 6.350, 7.002, P<0.05). The cell proliferation ability of PANC-1 cells in miR-15b low expression group at 2, 3 and 4 d(0.48±0.05, 0.76±0.13, 1.44±0.25) was significantly decreased correspondingly as compared with that in the control group (0.58±0.07, 0.98±0.13, 1.86±0.14) (t=9.988, 10.022, 13.050, P<0.01). The number of CFPAC-1 and PANC-1 cells migrating through the Transwell chamber in the miR-15b low-expression group (38.47±4.69 and 47.83±12.47) was significantly lower than that in the control group (62.39±7.39 and 68.97±8.44) (t=5.798, 8.465, P<0.05). The apoptosis rate of CFPAC-1 and PANC-1 cells in the miR-15b low-expression group [(14.68±3.21)% and (11.57±2.52)%] was significantly higher corresponding than that in the control group [(4.29±1.42)% and (4.73±0.38)%] (t=6.350, 8.666, P<0.05). Conclusion MiR-15b is highly expressed in PC cells. Low expression of miR-15b can decrease the proliferation and migration of PC cells and promote apoptosis of PC cells. Key words: MicroRNA-15b; Proliferation; Migration; Apoptosis