MiR-193b, downregulated in Ewing Sarcoma, targets the ErbB4 oncogene to inhibit anchorage-independent growth

PLoS One. 2017 May 18;12(5):e0178028. doi: 10.1371/journal.pone.0178028. eCollection 2017.

Abstract

Ewing Sarcoma is an aggressive, oncofusion-driven, malignant neoplasm of bone and soft tissue affecting predominantly children and young adults. Seeking to identify potential novel therapeutic targets/agents for this disease, our previous studies uncovered microRNAs regulated by EWS/Fli1, the most common oncofusion, with growth modulatory properties. In the present study, we sought to identify EWS/Fli1-repressed, growth suppressive, microRNAs potentially amenable to replacement in Ewing Sarcoma cells. Eight microRNAs (143, 153, 184, 193b, 195, 203, 206 and 223) were selected for evaluation as EWS/Fli1-repressed and underexpressed in Ewing Sarcoma cells, and reported to be growth suppressive in other pediatric or/and adult cancers. The selected miRs, and appropriate non-targeting controls, were introduced into two different Ewing Sarcoma cell lines (A673 and SK-ES-1), and effects on growth were examined using a high and low-density growth assay. MiR-193b was growth inhibitory in both assays and cell lines. In subsequent analyses, we found that stable overexpression of miR-193b also inhibits anchorage-independent growth in both A673 and SK-ES-1 cells. We further show that miR-193b negatively regulates expression of the ErbB4 oncogene in A673 and SK-ES-1 cells, and that depletion of ErbB4 is itself inhibitory to anchorage-independent growth in the same cell lines. Together, our studies show that the EWS/Fli1-repressed miR-193b is growth suppressive in Ewing Sarcoma, and identify ErbB4 as a target gene and candidate mediator of this growth suppression.

MeSH terms

  • 3' Untranslated Regions
  • Antagomirs / metabolism
  • Base Sequence
  • Bone Neoplasms / metabolism
  • Bone Neoplasms / pathology
  • Cell Line, Tumor
  • Cell Proliferation
  • Down-Regulation
  • Humans
  • MicroRNAs / antagonists & inhibitors
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • Oncogene Proteins, Fusion / metabolism
  • Proto-Oncogene Protein c-fli-1 / metabolism
  • RNA Interference
  • RNA, Small Interfering / metabolism
  • RNA-Binding Protein EWS / metabolism
  • Receptor, ErbB-4 / antagonists & inhibitors
  • Receptor, ErbB-4 / genetics
  • Receptor, ErbB-4 / metabolism*
  • Sarcoma, Ewing / metabolism
  • Sarcoma, Ewing / pathology
  • Sequence Alignment

Substances

  • 3' Untranslated Regions
  • Antagomirs
  • EWS-FLI fusion protein
  • MicroRNAs
  • Oncogene Proteins, Fusion
  • Proto-Oncogene Protein c-fli-1
  • RNA, Small Interfering
  • RNA-Binding Protein EWS
  • ERBB4 protein, human
  • Receptor, ErbB-4