Hypoxia-inducible miR-210 regulates the susceptibility of tumor cells to lysis by cytotoxic T cells

Cancer Res. 2012 Sep 15;72(18):4629-41. doi: 10.1158/0008-5472.CAN-12-1383. Epub 2012 Sep 7.

Abstract

Hypoxia in the tumor microenvironment plays a central role in the evolution of immune escape mechanisms by tumor cells. In this study, we report the definition of miR-210 as a miRNA regulated by hypoxia in lung cancer and melanoma, documenting its involvement in blunting the susceptibility of tumor cells to lysis by antigen-specific cytotoxic T lymphocytes (CTL). miR-210 was induced in hypoxic zones of human tumor tissues. Its attenuation in hypoxic cells significantly restored susceptibility to autologous CTL-mediated lysis, independent of tumor cell recognition and CTL reactivity. A comprehensive approach using transcriptome analysis, argonaute protein immunoprecipitation, and luciferase reporter assay revealed that the genes PTPN1, HOXA1, and TP53I11 were miR-210 target genes regulated in hypoxic cells. In support of their primary importance in mediating the immunosuppressive effects of miR-210, coordinate silencing of PTPN1, HOXA1, and TP53I11 dramatically decreased tumor cell susceptibility to CTL-mediated lysis. Our findings show how miR-210 induction links hypoxia to immune escape from CTL-mediated lysis, by providing a mechanistic understanding of how this miRNA mediates immunosuppression in oxygen-deprived regions of tumors where cancer stem-like cells and metastatic cellular behaviors are known to evolve.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blotting, Western
  • Cell Death
  • Cell Hypoxia / physiology
  • Cell Line, Tumor
  • Cytotoxicity, Immunologic / immunology*
  • Flow Cytometry
  • Gene Silencing
  • Humans
  • Immunohistochemistry
  • Immunoprecipitation
  • MicroRNAs / immunology*
  • MicroRNAs / metabolism
  • Neoplasms / immunology
  • Neoplasms / pathology
  • RNA Interference
  • Reverse Transcriptase Polymerase Chain Reaction
  • T-Lymphocytes, Cytotoxic / immunology*
  • Transfection
  • Tumor Escape / immunology*
  • Tumor Microenvironment / physiology

Substances

  • MIRN210 microRNA, human
  • MicroRNAs