microRNA-153 Targets mTORC2 Component Rictor to Inhibit Glioma Cells

PLoS One. 2016 Jun 13;11(6):e0156915. doi: 10.1371/journal.pone.0156915. eCollection 2016.

Abstract

Rictor upregulation and mTORC complex 2 (mTORC2) over-activation participate in glioma cell progression, yet the underling mechanisms are not known. We here identified microRNA-153 (miR-153) as a potential anti-Rictor miRNA, which was downregulated in multiple human glioma tissues and glioma cell lines (U87MG, T98G, U373MG and U251MG). miR-153 downregulation was correlated with Rictor (mRNA and protein) upregulation and p-Akt Ser473 (the mTORC2 indicator) over-activation in the glioma tissues and cells. Our in vitro evidences suggested that Rictor could be one primary target of miR-153 in glioma cells. Exogenous overexpression of miR-153 downregulated Rictor (mRNA and protein) and decreased p-Akt Ser473 in U87MG cells, leading to significant growth inhibition and apoptosis activation. Notably, U87MG cells with Rictor shRNA knockdown showed similar phenotypes of cells with miR-153 overexpression. More importantly, in Rictor-silenced U87MG cells, miR-153 expression failed to further affect cell growth nor apoptosis. In vivo, we showed that miR-153 overexpression dramatically inhibited U87MG tumor growth in nude mice. Together, these results suggest that miR-153 downregulation could be one important reason of Rictor upregulation and mTORC2 over-activation in glioma cells. Further, miR-153-induced anti-glioma cell activity is possibly via downregulating Rictor.

MeSH terms

  • Animals
  • Carrier Proteins / genetics*
  • Carrier Proteins / metabolism
  • Cell Line, Tumor
  • Cell Proliferation / genetics*
  • Down-Regulation / genetics
  • Female
  • Gene Expression Regulation, Neoplastic
  • Glioma / genetics*
  • Glioma / pathology
  • Humans
  • Mechanistic Target of Rapamycin Complex 2
  • Mice
  • Mice, Nude
  • MicroRNAs / physiology*
  • Multiprotein Complexes / genetics
  • Multiprotein Complexes / metabolism
  • Rapamycin-Insensitive Companion of mTOR Protein
  • TOR Serine-Threonine Kinases / genetics
  • TOR Serine-Threonine Kinases / metabolism
  • Xenograft Model Antitumor Assays

Substances

  • Carrier Proteins
  • MIRN153 microRNA, human
  • MicroRNAs
  • Multiprotein Complexes
  • RICTOR protein, human
  • Rapamycin-Insensitive Companion of mTOR Protein
  • Mechanistic Target of Rapamycin Complex 2
  • TOR Serine-Threonine Kinases

Grants and funding

This study was supported by the research fund of the Second Xiangya Hospital of Central South University (2013-029, to YJ). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.