HIF2-Induced Long Noncoding RNA RAB11B-AS1 Promotes Hypoxia-Mediated Angiogenesis and Breast Cancer Metastasis

Cancer Res. 2020 Mar 1;80(5):964-975. doi: 10.1158/0008-5472.CAN-19-1532. Epub 2020 Jan 3.

Abstract

Hypoxia induces a vast array of long noncoding RNAs (lncRNA) in breast cancer cells, but their biological functions remain largely unknown. Here, we identified a hitherto uncharacterized hypoxia-induced lncRNA RAB11B-AS1 in breast cancer cells. RAB11B-AS1 is a natural lncRNA upregulated in human breast cancer and its expression is induced by hypoxia-inducible factor 2 (HIF2), but not HIF1, in response to hypoxia. RAB11B-AS1 enhanced the expression of angiogenic factors including VEGFA and ANGPTL4 in hypoxic breast cancer cells by increasing recruitment of RNA polymerase II. In line with increased angiogenic factors, conditioned media from RAB11B-AS1-overexpressing breast cancer cells promoted tube formation of human umbilical vein endothelial cells in vitro. Gain- and loss-of-function studies revealed that RAB11B-AS1 increased breast cancer cell migration and invasion in vitro and promoted tumor angiogenesis and breast cancer distant metastasis without affecting primary tumor growth in mice. Taken together, these findings uncover a fundamental mechanism of hypoxia-induced tumor angiogenesis and breast cancer metastasis. SIGNIFICANCE: This study reveals the molecular mechanism by which the lncRNA RAB11B-AS1 regulates hypoxia-induced angiogenesis and breast cancer metastasis, and provides new insights into the functional interaction between a lncRNA and tumor microenvironment. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/80/5/964/F1.large.jpg.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiopoietin-Like Protein 4 / genetics
  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / metabolism*
  • Breast Neoplasms / blood supply
  • Cell Hypoxia / genetics
  • Cell Line, Tumor
  • Endothelial Cells
  • Female
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism
  • Mice
  • Neoplasm Metastasis / genetics
  • Neovascularization, Pathologic / genetics*
  • Neovascularization, Pathologic / pathology
  • RNA Polymerase II / metabolism
  • RNA, Long Noncoding / metabolism*
  • Tumor Microenvironment / genetics
  • Up-Regulation
  • Vascular Endothelial Growth Factor A / genetics
  • Xenograft Model Antitumor Assays

Substances

  • ANGPTL4 protein, human
  • Angiopoietin-Like Protein 4
  • Basic Helix-Loop-Helix Transcription Factors
  • HIF1A protein, human
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • RNA, Long Noncoding
  • VEGFA protein, human
  • Vascular Endothelial Growth Factor A
  • endothelial PAS domain-containing protein 1
  • RNA Polymerase II