MicroRNA-527 inhibits TGF-β/SMAD induced epithelial-mesenchymal transition via downregulating SULF2 expression in non-small-cell lung cancer.

Abstract

To explore the potential mechanism which miR-527 targeting the heparan sulfate 6-O-endosulfatase (SULF2) regulates TGF-β/SMAD signaling pathway induced epithelial-mesenchymal transition (EMT) in non-small-cell lung cancer (NSCLC). 38 pairs of lung tumor biopsies and corresponding paracancerous biopsies were obtained from NSCLC patients with surgical resection, normal human bronchial epithelial BEAS-2B cells and five NSCLS cell lines were applied for our study. miR-527 and SULF2 expression were determined by qRT-PCR and immunohistochemistry. MiR-527 and SULF2 biological link were predicted by Targetscan.org and tested by dual luciferase. Cells proliferation and apoptosis were respectively detected by EDU staining and flow cytometry. Cells migration was examined by transwell and scratch-wound assay. Expression of proteins related to EMT and TGF-β/SMAD signaling pathway, such as E-cadherin, N-cadherin, p-Samd3 and p-Smad2, was detected by western blot. miR-527 expression was decreased in lung tumor tissues and NSCLS cell lines, conversely, SULF2 expression was significantly increased. In addition, we found that miR-527 targeted 3'-untranslated regions (3'-UTR) of SULF2 and mediated its expression. Overexpression of miR-527 evidently suppressed NSCLC proliferation, invasion and EMT via TGF-β/SMAD signaling pathway. Moreover, the silence of SULF2 exhibited a similar effect. miR-527 targeting SULF2 down-regulated SULF2 expression, concurrently, suppressed NSCLC epithelial-mesenchymal transition and invasion via inhibiting TGF-β/SMAD signaling pathway.