Role of miR-92a-3p/PTEN axis in regulation of pancreatic cancer cell proliferation and metastasis.

Abstract

To explore the effect of miR-92a-3p on the proliferation and metastasis of pancreatic cancer cells via targeting phosphatase and tension homolog deleted on chromosome ten (PTEN). MiR-92a-3p expression and PTEN protein levels were quantified in a normal pancreatic cells (HPDE6-C7) and 5 pancreatic cancer cell lines (Panc-1, BxPC-3, AsPC-1,MIA Paca-2, and Capan-2) by real-time PCR and Western blotting, respectively. BxPC-3 and Panc-1 cells were selected for further experiment. After transfection of normal control (NC) mimics (NC mimics group), miR-92a-3p mimics (miR-92a-3p mimics group), NC inhibitor or miR-92a-3p inhibitor (NC inhibitor group or miR-92a-3p inhibitor group), the proliferation of BxPC-3 and Panc-1 cells was measured by cell counting kit-8 (CCK-8), and the migration of them was measured by Transwell assay, and the levels of PTEN protein were measured by Western blotting. In addition, wild-type PTEN 3'-UTR (wt-PTEN 3'UTR) and mutant-type PTEN 3'-UTR (mut-PTEN 3'UTR) luciferase reporter vectors were constructed and co-transfected with NC mimics, miR-92a-3p mimic, NC inhibitor or miR-92a-3p inhibitor into 293T tool cells, and then the dual luciferase reporter assay was performed to examine the regulative correlation between miR-92a-3p and PTEN. The BxPC-3 cells were divided into 4 groups: a NC inhibitor+si-NC group, a miR-92a-3p inhibitor+si-NC group, a NC inhibitor+si-PTEN group, and a miR-92a-3p inhibitor+si-PTEN group. The Panc-1 cells were also assigned into 4 groups: a NC mimics+NC group, a miR-92a-3p mimics+si-NC group, a NC mimics+ PTEN group, and a miR-92a-3p mimics+PTEN group. The proliferation of Panc-1 cells was measured by CCK-8; the cell migration was measured by Transwell assay, and the levels of PTEN protein were measured by Western blotting. The miR-92a-3p was highly expressed in pancreatic cancer cell lines (allP<0.01), while the PTEN protein levels were lower in pancreatic cancer cell lines (allP<0.05)compared with that in the HPDE6-C7 cells. Compared with the NC mimics group, the cell viability of BxPC-3 and Panc-1 cells were both increased in the miR-92a-3p mimics group (bothP<0.01); compared with the inhibitor group, the cell viability of BxPC-3 and Panc-1 cells were both decreased in the miR-92a-3p inhibitor group (bothP<0.01). Compared with the NC mimics group, the cell number of BxPC-3 and Panc-1 cells through micropores were increased in the miR-92a-3p mimics group (bothP<0.01); compared with the inhibitor group, the cell number of BxPC-3 and Panc-1 cells through micropores were decreased in the miR-92a-3p inhibitor group (bothP<0.01). Compared with NC mimics group, the activity of dual luciferaseof wt-PTEN3'-UTR was inhibited in the miR-92a-3p mimics group (P<0.01); compared with the NC inhibitor group, the activity of dual luciferase of wt-PTEN3'-UTR was promoted in the miR-92a-3p inhibitor group (P<0.01). Compared with the miR-92a-3p inhibitor+si-NC group, the suppressive effects of miR-92a-3p on the proliferation and metastasis of BxPC-3 cells was restored in the miR-92a-3p inhibitor+si-PTEN group; while compared with the miR-92a-3p mimics+NC group, the positive effects of miR-92a-3p overexpression on the proliferation and metastasis of Panc-1 cells was restored in the miR-92a-3p mimics+PTEN group. The highly expressed miR-92a-3p in pancreatic cancer cells can decrease the protein levels of PTEN, thereby enhancing the proliferation and metastasis activity of pancreatic cancer cells.