The effects of microRNA-181b on proliferation and invasion of pancreatic cancer cells

Abstract

Objective To investigate the effects of microRNA-181b (miR-181b) on cell proliferation and invasion of pancreatic cancer cells. Methods MiR-181b expression levels in 3 pancreatic cancer cell lines PANC-1, BXPC-3, ASPC-1 and normal pancreatic HTERT-HPNE cells were observed by quantitative reverse transcription-polymerase chain reaction (RT-qPCR). PANC-1 cells were transfected with 50 nmol/L miR-181b inhibitor or negative control using Lipofectamine 2000. After transfection, the expression of miR-181b was measured by RT-qPCR. Cell proliferation was tested by methylthiazol tetrazolium (MTT) assay. Cell invasion was detected by transwell. Bioinformatics prediction and luciferase activity tests were to verify phosphate and tension homology deleted on chromsome ten (PTEN) was the targeted gene of miR-181b. The expression levels of PTEN, matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) were measured by RT-qPCR. Results Compared with the HTERT-HPNE cells (1.00±0.06), the expression level of miR-181b in PANC-1 (2.84±0.16), BXPC-3 (1.74±0.18), ASPC-1 (2.21±0.20) was significantly increased. After transfection with 50 nmol/L miR-181b inhibitor, there was no obvious change in PANC-1 cell proliferation (P>0.05), and cell invasive ability was inhibited (P<0.01). Bioinformatics predicted PTEN might be the targeted gene of miR-181b. Luciferase experiments showed that luciferase activity of wild-type PTEN group fell by 39% after transfection of miR-181b mimics, but there was no statistical difference in the mutant group. After transfection with miR-181b inhibitor, PTEN was significantly increased (1.85±0.06 vs. 1.01±0.08, P<0.05), and MMP-2 (0.59±0.02 vs. 1.01±0.04) and MMP-9 (0.66±0.02 vs. 0.99±0.07) were significantly decreased (P<0.05). Conclusion These results demonstrate that miR-181b promotes proliferation and invasion in pancreatic cancer cells, which may be partly related to effecting MMP-2 and MMP-9 expression by PTEN. Therefore, it may be a new target for the biologic therapy for pancreatic cancer. Key words: Pancreatic cancer; MicroRNA-181b; Proliferation; Invasion