microRNA-155, induced by interleukin-1ß, represses the expression of microphthalmia-associated transcription factor (MITF-M) in melanoma cells

PLoS One. 2015 Apr 8;10(4):e0122517. doi: 10.1371/journal.pone.0122517. eCollection 2015.

Abstract

Loss of expression of surface antigens represents a significant problem for cancer immunotherapy. Microphthalmia-associated transcription factor (MITF-M) regulates melanocyte fate by driving expression of many differentiation genes, whose protein products can be recognized by cytolytic T lymphocytes. We previously reported that interleukin-1ß (IL-1ß) can downregulate MITF-M levels. Here we show that downregulation of MITF-M expression by IL-1ß was paralleled by an upregulation of miR-155 expression in four melanoma lines. We confirmed that miR-155 was able to target endogenous MITF-M in melanoma cells and demonstrated a role for miR-155 in the IL-1ß-induced repression of MITF-M by using an antagomiR. Notably, we also observed a strong negative correlation between MITF-M and miR-155 levels in a mouse model of melanoma. Taken together, our results indicate that MITF-M downregulation by inflammatory stimuli might be partly due to miR-155 upregulation. This could represent a novel mechanism of melanoma immune escape in an inflammatory microenvironment.

MeSH terms

  • Animals
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Immunotherapy
  • Interleukin-1beta / genetics*
  • Interleukin-1beta / metabolism
  • Melanoma / genetics*
  • Melanoma / pathology
  • Mice
  • MicroRNAs / biosynthesis
  • MicroRNAs / genetics*
  • Microphthalmia-Associated Transcription Factor / biosynthesis*
  • Microphthalmia-Associated Transcription Factor / genetics

Substances

  • Interleukin-1beta
  • MIRN155 microRNA, human
  • MicroRNAs
  • Microphthalmia-Associated Transcription Factor

Grants and funding

N.A. was supported by a FRIA Grant from the Fonds National de la Recherche Scientifique (FNRS) (Belgium) and the Centre du Cancer (Cliniques Universitaires Saint-Luc, UCL, Belgium). S.C., M.H., and J.L. were supported by a Télévie Grant from the Fonds National de la Recherche Scientifique (FNRS) (Belgium). This work was supported in part by Grants from the Fondation Contre le Cancer (Belgium) and from the FNRS (FRSM, Grant 3.4.559.08.F). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.