Fra-2/AP-1 regulates melanoma cell metastasis by downregulating Fam212b

Cell Death Differ. 2021 Apr;28(4):1364-1378. doi: 10.1038/s41418-020-00660-4. Epub 2020 Nov 13.

Abstract

Metastatic melanoma remains a challenging disease. Understanding the molecular mechanisms how melanoma becomes metastatic is therefore of interest. Herein we show that downregulation of the AP-1 transcription factor member Fra-2 in melanoma cells is associated with an aggressive melanoma phenotype in vitro and in vivo. In vitro, Fra-2 knockdown in melanoma cells promoted cell migration and invasion associated with increased Snail-1, Twist-1/2, and matrix metalloproteinase-2 (MMP-2) expression. In vivo, Fra-2 knockdown in a melanoma cell line led to increased metastasis into the lungs and liver. The increased metastatic potential of Fra-2 knockdown melanoma cells was likely due to an accelerated cell cycle transition and increased tissue angiogenesis. Using Fra-2 knockdown cell lines microarray analysis, we identified the protein Fam212b (family with sequence similarity 212 member B) as a downstream target of Fra-2. By additional knockdown of Fam212b in Fra-2 mutant cells, we mitigated the cell migration, invasion, and cell cycle transition phenotype induced by Fra-2 knockdown. Furthermore, Fam212b overexpression enhanced β-catenin pathway. Finally, Fam212b expression is correlated with increased melanoma metastasis and poor clinical outcomes in human patients. In summary, these findings reveal the Fra-2-Fam212b axis as a new pathway of melanoma metastasis, which can be in the future used as potential marker of the metastatic properties of melanoma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line, Tumor
  • Cell Movement / genetics
  • Down-Regulation
  • Fos-Related Antigen-2 / genetics
  • Fos-Related Antigen-2 / metabolism*
  • Humans
  • Intracellular Signaling Peptides and Proteins / genetics
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Male
  • Matrix Metalloproteinase 2 / genetics
  • Matrix Metalloproteinase 2 / metabolism
  • Melanoma / metabolism*
  • Melanoma / pathology
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Mice, Nude
  • Neoplasm Invasiveness
  • Neoplasm Metastasis
  • Proto-Oncogene Proteins c-fos / genetics
  • Proto-Oncogene Proteins c-fos / metabolism*
  • Transcription Factor AP-1 / metabolism*
  • beta Catenin / metabolism

Substances

  • FOS protein, human
  • FOSL2 protein, human
  • Fos-Related Antigen-2
  • Inka1 protein, human
  • Intracellular Signaling Peptides and Proteins
  • Proto-Oncogene Proteins c-fos
  • Transcription Factor AP-1
  • beta Catenin
  • Matrix Metalloproteinase 2