Hypoxia-inducible miR-182 enhances HIF1α signaling via targeting PHD2 and FIH1 in prostate cancer

Sci Rep. 2015 Jul 24:5:12495. doi: 10.1038/srep12495.

Abstract

Activation of hypoxia-inducible factor 1α (HIF1α) controls the transcription of genes governing angiogenesis under hypoxic condition during tumorigenesis. Here we show that hypoxia-responsive miR-182 is regulated by HIF1α at transcriptional level. Prolyl hydroxylase domain enzymes (PHD) and factor inhibiting HIF-1 (FIH1), negative regulators of HIF1 signaling, are direct targets of miR-182. Overexpression of miR-182 in prostate cancer cells led to a reduction of PHD2 and FIH1 expression and an increase in HIF1α level either under normoxic or hypoxic condition. Consistently, inhibition of miR-182 could increase PHD2 and FIH1 levels, thereby reducing the hypoxia-induced HIF1α expression. Matrigel plug assay showed that angiogenesis was increased by miR-182 overexpression, and vice versa. miR-182 overexpression in PC-3 prostate cancer xenografts decreased PHD2 and FIH1 expression, elevated HIF1α protein levels, and increased tumor size. Lastly, we revealed that the levels of both miR-182 and HIF1α were elevated, while the expression PHD2 and FIH1 was downregulated in a mouse model of prostate cancer. Together, our results suggest that the interplay between miR-182 and HIF1α could result in a sustained activation of HIF1α pathway, which might facilitate tumor cell adaption to hypoxic stress during prostate tumor progression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Hypoxia / genetics
  • Cell Line, Tumor
  • Heterografts
  • Hypoxia-Inducible Factor 1, alpha Subunit / genetics
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism*
  • Hypoxia-Inducible Factor-Proline Dioxygenases / genetics
  • Hypoxia-Inducible Factor-Proline Dioxygenases / metabolism*
  • Male
  • Mice
  • Mice, Knockout
  • MicroRNAs / biosynthesis*
  • MicroRNAs / metabolism
  • Mixed Function Oxygenases / genetics
  • Mixed Function Oxygenases / metabolism*
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / metabolism*
  • Neoplasm Transplantation
  • Neovascularization, Pathologic / genetics
  • Neovascularization, Pathologic / metabolism
  • Neovascularization, Pathologic / pathology
  • Prostatic Neoplasms / genetics
  • Prostatic Neoplasms / metabolism*
  • Prostatic Neoplasms / pathology
  • RNA, Neoplasm / biosynthesis*
  • RNA, Neoplasm / genetics
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism*
  • Signal Transduction*

Substances

  • HIF1A protein, human
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • MicroRNAs
  • Mirn182 microRNA, human
  • Neoplasm Proteins
  • RNA, Neoplasm
  • Repressor Proteins
  • Mixed Function Oxygenases
  • HIF1AN protein, human
  • EGLN1 protein, human
  • Hypoxia-Inducible Factor-Proline Dioxygenases