Long non-coding RNA taurine upregulated 1 enhances tumor-induced angiogenesis through inhibiting microRNA-299 in human glioblastoma

Oncogene. 2017 Jan 19;36(3):318-331. doi: 10.1038/onc.2016.212. Epub 2016 Jun 27.

Abstract

Angiogenesis is one of the critical biological elements affecting the development and progression of cancer. Long non-coding RNAs (lncRNAs) are important regulators and aberrantly expressed in various types of human cancer. Our previous studies indicated that lncRNA taurine upregulated 1 (TUG1) implicated in the regulation of blood-tumor barrier permeability; however, its role in glioblastoma angiogenesis still unclear. Here we demonstrated that TUG1 was up-expressed in human glioblastoma tissues and glioblastoma cell lines. Knockdown of TUG1 remarkably suppressed tumor-induced endothelial cell proliferation, migration and tube formation as well as reducing spheroid-based angiogenesis ability in vitro, which are the critical steps for tumor angiogenesis. Besides, knockdown of TUG1 significantly increased the expression of mircroRNA-299 (miR-299), which was down-expressed in glioblastoma tissues and glioblastoma cell lines. Bioinformatics analysis and luciferase reporter assay revealed that TUG1 influenced tumor angiogenesis via directly binding to the miR-299 and there was a reciprocal repression between TUG1 and miR-299 in the same RNA-induced silencing complex. Moreover, knockdown of TUG1 reduced the expression of vascular endothelial growth factor A (VEGFA), which was defined as a functional downstream target of miR-299. In addition, knockdown of TUG1, shown in the in vivo studies, has effects on suppressing tumor growth, reducing tumor microvessel density and decreasing the VEGFA expression by upregulating miR-299 in xenograft glioblastoma model. Overall, the results demonstrated that TUG1 enhances tumor-induced angiogenesis and VEGF expression through inhibiting miR-299. Also, the inhibition of TUG1 could provide a novel therapeutic target for glioblastoma treatment.

MeSH terms

  • 3' Untranslated Regions
  • Animals
  • Brain Neoplasms / genetics
  • Brain Neoplasms / metabolism
  • Brain Neoplasms / pathology*
  • Cell Line, Tumor
  • Cell Proliferation
  • Gene Expression Regulation, Neoplastic
  • Gene Knockdown Techniques
  • Glioblastoma / genetics
  • Glioblastoma / metabolism
  • Glioblastoma / pathology*
  • Humans
  • Mice
  • MicroRNAs / genetics*
  • Neoplasm Transplantation
  • RNA, Long Noncoding / genetics*
  • Up-Regulation
  • Vascular Endothelial Growth Factor A / genetics*
  • Vascular Endothelial Growth Factor A / metabolism

Substances

  • 3' Untranslated Regions
  • MIRN299 microRNA, human
  • MicroRNAs
  • RNA, Long Noncoding
  • TUG1 long noncoding RNA, human
  • VEGFA protein, human
  • Vascular Endothelial Growth Factor A