Hypoxia-induced miR-210 promoter demethylation enhances proliferation, autophagy and angiogenesis of schwannoma cells

Oncol Rep. 2017 May;37(5):3010-3018. doi: 10.3892/or.2017.5511. Epub 2017 Mar 16.

Abstract

Hypoxia, a dominant feature in cancer occurrence and evolution, exists throughout the progression of most malignant tumors. This study focused on the mechanism of hypoxia-induced miR-210 upregulation, and the miR-210 functions in schwannoma. We detected microvascular density, vascular endothelial growth factor (VEGF) and miR-210 expression levels using schwannoma tissue mciroarray. The results showed that miR-210 expression was significantly associated with VEGF. Moreover, the cytological tests showed that hypoxia induced miR-210 expression, while reduce ephrin-A3 expression. The bisulfate genomic sequencing PCR results showed that miR-210 promoter region was hypermethylated in RT4-D6P2T in normoxia, while demethylated in hypoxia, and the region included the hypoxia-inducible factor-1α (HIF-1α) response element site. Cellular function research showed that hypoxia resulted in RT4-D6P2T apoptosis, higher autophage and invasion. Besides, hypoxia can affect HIF-1α/VEGF-mediated angiogenesis. To learn about the specific functions of miR-210, we found that with miR-210 inhibition, tumor cell apoptosis increased, autophagy and angiogenesis reduced, and the cell cycle was arrested. Hypoxia promoted miR-210 expression through promoter demethylation, then consequently enhanced tumor cell proliferation and autophagy, increasing tumor cell angiogenesis. Thus, miR-210 could be a potential marker for judging tumor malignancy and be taken as an effective target for clinical auxiliary treatment of neurilemmoma.

MeSH terms

  • Autophagy
  • Cell Hypoxia
  • Cell Line, Tumor
  • Cell Proliferation
  • DNA Methylation*
  • Ephrin-A3 / genetics
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Hypoxia-Inducible Factor 1, alpha Subunit / genetics
  • MicroRNAs / genetics*
  • Neurilemmoma / blood supply
  • Neurilemmoma / genetics*
  • Promoter Regions, Genetic
  • Up-Regulation*
  • Vascular Endothelial Growth Factor A / genetics

Substances

  • Ephrin-A3
  • HIF1A protein, human
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • MIRN210 microRNA, human
  • MicroRNAs
  • VEGFA protein, human
  • Vascular Endothelial Growth Factor A