FOXF2 deficiency accelerates the visceral metastasis of basal-like breast cancer by unrestrictedly increasing TGF-β and miR-182-5p

Cell Death Differ. 2020 Oct;27(10):2973-2987. doi: 10.1038/s41418-020-0555-7. Epub 2020 May 18.

Abstract

The mesenchymal transcription factor forkhead box F2 (FOXF2) is a critical regulator of embryogenesis and tissue homeostasis. Our previous studies demonstrated that FOXF2 is ectopically expressed in basal-like breast cancer (BLBC) cells and that FOXF2 deficiency promotes the epithelial-mesenchymal transition and aggressiveness of BLBC cells. In this study, we found that FOXF2 controls transforming growth factor-beta (TGF-β)/SMAD signaling pathway activation through transrepression of TGF-β-coding genes in BLBC cells. FOXF2-deficient BLBC cells adopt a myofibroblast-/cancer-associated fibroblast (CAF)-like phenotype, and tend to metastasize to visceral organs by increasing autocrine TGF-β signaling and conferring aggressiveness to neighboring cells by increasing paracrine TGF-β signaling. In turn, TGF-β silences FOXF2 expression through upregulating miR-182-5p, a posttranscriptional regulator of FOXF2 and inducer of metastasis. In addition to mediating a reciprocal repression loop between FOXF2 and TGF-β through direct transrepression by SMAD3, miR-182-5p forms a reciprocal repression loop with FOXF2 that directly transrepresses MIR182 expression. Therefore, FOXF2 deficiency accelerates the visceral metastasis of BLBC through unrestricted increases in autocrine and paracrine TGF-β signaling, and miR-182-5p expression. Our findings provide novel mechanisms underlying the roles of TGF-β, miR-182-5p, and FOXF2 in accelerating BLBC dissemination and metastasis, and may facilitate the development of therapeutic strategies for aggressive BLBC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Breast Neoplasms / metabolism*
  • Cell Movement
  • Female
  • Forkhead Transcription Factors / physiology*
  • Gene Expression Regulation, Neoplastic
  • Humans
  • MCF-7 Cells
  • Mice
  • Mice, SCID
  • MicroRNAs / metabolism*
  • Transforming Growth Factor beta / metabolism*

Substances

  • FOXF2 protein, human
  • Forkhead Transcription Factors
  • MicroRNAs
  • Mirn182 microRNA, human
  • Transforming Growth Factor beta