MicroRNA-127 is Aberrantly Downregulated and Acted As a Functional Tumor Suppressor in Human Pancreatic Cancer

Pancreatic carcinoma is one of the most malignant human cancers. In this study, we intended to explore the molecular functional of microRNA-127 (miR-127) in regulating pancreatic cancer development both in vitro and in vivo. Quantitative real-time PCR (qRT-PCR) was performed to evaluate endogenous miR-127 expression in in vitro pancreatic cancer cell lines and in vivo clinical samples of pancreatic carcinoma. Lentiviral technology was applied to overexpress miR-127 in capan-1 and PANC-1 cells. Pancreatic cancer proliferation, cell-cycle progression, and invasion were assessed in vitro, and capan-1-derived tumorigenicity was evaluated in vivo. Dual-luciferase reporter assay and qRT-PCR were performed to assess the downstream target gene of miR-127 in pancreatic cancer, human Bcl-2-associated athanogene 5 (BAG5). BAG5 was subsequently upregulated in miR-127-overexpressed capan-1 and PANC-1 cells to evaluate its effect on pancreatic cancer progression. MiR-127 was preferentially downregulated in both pancreatic carcinoma cell lines and human pancreatic tumors. In lentivirus-infected capan-1 and PANC-1 cells, miR-127 overexpression significantly inhibited cancer progression, cell-cycle transition and invasion in vitro, as well as tumorigenicity in vivo. Human BAG5 was confirmed to be the downstream target of miR-127 in pancreatic cancer. Forced overexpression of BAG5 in capan-1 and PANC-1 cells reversed the tumor-suppressing effect of miR-127 on cancer development. MiR-127 is downregulated and acting as a tumor suppressor in pancreatic carcinoma. The functional regulation of miR-127 in pancreatic carcinoma is very likely through the inverse correlation of its downstream target gene of BAG5.