Extracellular vesicles modulate the glioblastoma microenvironment via a tumor suppression signaling network directed by miR-1

Cancer Res. 2014 Feb 1;74(3):738-750. doi: 10.1158/0008-5472.CAN-13-2650. Epub 2013 Dec 5.

Abstract

Extracellular vesicles have emerged as important mediators of intercellular communication in cancer, including by conveying tumor-promoting microRNAs between cells, but their regulation is poorly understood. In this study, we report the findings of a comparative microRNA profiling and functional analysis in human glioblastoma that identifies miR-1 as an orchestrator of extracellular vesicle function and glioblastoma growth and invasion. Ectopic expression of miR-1 in glioblastoma cells blocked in vivo growth, neovascularization, and invasiveness. These effects were associated with a role for miR-1 in intercellular communication in the microenvironment mediated by extracellular vesicles released by cancer stem-like glioblastoma cells. An extracellular vesicle-dependent phenotype defined by glioblastoma invasion, neurosphere growth, and endothelial tube formation was mitigated by loading miR-1 into glioblastoma-derived extracellular vesicles. Protein cargo in extracellular vesicles was characterized to learn how miR-1 directed extracellular vesicle function. The mRNA encoding Annexin A2 (ANXA2), one of the most abundant proteins in glioblastoma-derived extracellular vesicles, was found to be a direct target of miR-1 control. In addition, extracellular vesicle-derived miR-1 along with other ANXA2 extracellular vesicle networking partners targeted multiple pro-oncogenic signals in cells within the glioblastoma microenvironment. Together, our results showed how extracellular vesicle signaling promotes the malignant character of glioblastoma and how ectopic expression of miR-1 can mitigate this character, with possible implications for how to develop a unique miRNA-based therapy for glioblastoma management.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biological Transport
  • Brain Neoplasms / genetics*
  • Brain Neoplasms / metabolism*
  • Brain Neoplasms / pathology
  • Cell Line, Tumor
  • Cell Movement / genetics
  • Disease Models, Animal
  • Exosomes / metabolism*
  • Female
  • Gene Expression
  • Gene Expression Regulation, Neoplastic
  • Glioblastoma / genetics*
  • Glioblastoma / metabolism*
  • Glioblastoma / pathology
  • Humans
  • Mice
  • MicroRNAs / genetics*
  • MicroRNAs / metabolism
  • Neoplasm Invasiveness
  • Neovascularization, Pathologic / genetics
  • Neovascularization, Pathologic / metabolism
  • Signal Transduction
  • Spheroids, Cellular
  • Tumor Cells, Cultured
  • Tumor Microenvironment / genetics*

Substances

  • MIRN1 microRNA, human
  • MicroRNAs