MicroRNA-217 inhibits cell proliferation, invasion and migration by targeting Tpd52l2 in human pancreatic adenocarcinoma

MicroRNAs (miRNAs) play important roles in the regulation of various tumor biological processes including proliferation and apoptosis. miR-217 has been implicated in many types of cancer, whereas its expression and potential biological function in human pancreatic adenocarcinoma (HPAC) remain unclear. We aimed to investigate the clinical significance of miR-217 in patients with pancreatic carcinoma and its role and underlying molecular mechanism in HPAC. We collected 15 pairs of pancreatic cancer and normal pancreas tissues to evaluate the expression of miR-217 and tumor protein D52-like 2 (Tpd52l2). Then, we transfected AsPC-1 cells with miR-217 mimics or Tpd52l2 siRNA to detect the effect on cell proliferation, apoptosis, invasion, migration and the cell cycle. In addition, miR-217 mimics and Tpd52l2 expression plasmids were co-transfected into AsPC-1 cells to further investigate the mechanism of miR-217 and Tpd52l2 in HPAC tumorigenesis. Finally, exploration of related signaling pathways was carried out. Herein, we found that the expression of miR-217 was significantly downregulated in HPAC tissues as compared with that observed in adjacent normal tissues. Further functional assays showed that restoration of the expression of miR-217 inhibited cell proliferation, invasion and migration, induced apoptosis, and caused cell cycle arrest of HPAC cells. Notably, Tpd52l2 was identified as a functional target of miR-217 in HPAC. Furthermore, an inverse correlation between miR-217 and Tpd52l2 expression was observed in the HPAC tissues. Downregulation of Tpd52l2 had an effect similar to that following overexpression of miR-217, and upregulation of Tpd52l2 reversed the effects of the overexpression of miR-217. Finally, we found that overexpression of miR-217 or knockdown of Tpd52l2 suppressed the PIK3CA/AKT signaling pathways. In addition, this may explain the effect of miR-217/Tpd52l2 on HPAC development. Taken together, these results suggest a critical role of miR-217 in suppressing proliferation, migration and invasion of HPAC cells by targeting Tpd52l2. Targeting the miR-217/Tpd52l2 axis may be a new therapeutic application with which to treat patients with HPAC in the future.