miR-142-5p regulates pancreatic cancer cell proliferation and apoptosis by regulation of RAP1A.

Pancreatic cancer, one of the fatal and aggressive malignancies, leads the sixth cancer-associated death in China. microRNAs are believed to exert function in the diagnosis and treatment of pancreatic cancer. In the present study, we firstly found that miR-142-5p was downregulated in pancreatic cancer tumor tissues while Ras-related protein Rap-1 A (RAP1A) was upregulated compared with para-carcinoma non-tumor tissues. Then, we found that RAP1A could be a putative target gene of miR-142-5p by bioinformatics tool TargetScan. Furthermore, we conducted luciferase reporter assay, RT-qPCR, western blot and correlation analysis to demonstrate that miR-142-5p could negatively regulate RAP1A expression by binding to its 3'UTR. In addition, cell-counting kit 8 (CCK-8) and flow cytometry assays certified that miR-142-5p overexpression may inhibit pancreatic cancer cell proliferation but promote cell apoptosis; while the variation could be reversed by co-transfected with pcDNA3.1-RAP1A. Finally, miR-142-5p overexpression downregulated p-ERK1/2, phosphate p38 mitogen-activated protein kinases (p-p38); however, the variation induced by miR-142-5p mimic could be reversed by co-transfected with pcDNA3.1-RAP1A. In conclusion, our findings indicate that targeting miR-142-5p may provide a novel strategy for the treatment of pancreatic cancer.