Knockdown of NEAT1 restrained the malignant progression of glioma stem cells by activating microRNA let-7e

Oncotarget. 2016 Sep 20;7(38):62208-62223. doi: 10.18632/oncotarget.11403.

Abstract

Nuclear paraspeckle assembly transcript 1 (NEAT1), a long non-coding RNA, promotes oncogenesis in various tumors, including human gliomas. Herein, we studied the expression and function of NEAT1 in glioma stem cells (GSCs). Quantitative real-time PCR demonstrated that NEAT1 was upregulated in GSCs. NEAT1 knockdown inhibited GSC cell proliferation, migration and invasion and promoted GSC apoptosis. A potential binding region between NEAT1 and microRNA let-7e was confirmed by dual-luciferase assays. Upregulation of NEAT1 reduced the expression of let-7e, and there was reciprocal repression between NEAT1 and let-7e in an Argonaute 2-dependent manner. Let-7e expression was lower expression in glioblastoma tissues and GSCs than in normal brain tissues and cells. Restoration of let-7e suppressed tumor function by inhibiting proliferation, migration and invasion while promoting apoptosis in GSCs. NEAT1 knockdown and let-7e overexpression both reduced NRAS protein expression. NRAS was identified as a direct target of let-7e and promoted oncogenesis in GSCs. As NEAT1 promoted oncogenesis by downregulating let-7e expression, both of these genes could be considered for application in glioma therapy.

Keywords: NEAT1; NRAS; glioma stem cells; let-7e; lncRNAs.

MeSH terms

  • Animals
  • Apoptosis
  • Argonaute Proteins / metabolism
  • Brain / pathology
  • Brain Neoplasms / genetics*
  • Brain Neoplasms / pathology
  • Carcinogenesis / genetics*
  • Cell Line, Tumor
  • Cell Movement
  • Cell Proliferation
  • Disease Progression
  • GTP Phosphohydrolases / metabolism*
  • Gene Expression Regulation, Neoplastic*
  • Gene Knockdown Techniques
  • Glioblastoma / genetics*
  • Glioblastoma / pathology
  • HEK293 Cells
  • Humans
  • Immunohistochemistry
  • Male
  • Membrane Proteins / metabolism*
  • Mice
  • Mice, Nude
  • MicroRNAs / metabolism*
  • Neoplastic Stem Cells / pathology*
  • RNA Interference
  • RNA, Long Noncoding / genetics
  • RNA, Long Noncoding / metabolism*
  • RNA, Small Interfering / metabolism
  • Real-Time Polymerase Chain Reaction
  • Signal Transduction
  • Up-Regulation
  • Xenograft Model Antitumor Assays

Substances

  • AGO2 protein, human
  • Argonaute Proteins
  • Membrane Proteins
  • MicroRNAs
  • NEAT1 long non-coding RNA, human
  • RNA, Long Noncoding
  • RNA, Small Interfering
  • mirnlet7 microRNA, human
  • GTP Phosphohydrolases
  • NRAS protein, human