E3 ubiquitin ligase BCA2 promotes breast cancer stemness by up-regulation of SOX9 by LPS

Int J Biol Sci. 2024 Apr 29;20(7):2686-2697. doi: 10.7150/ijbs.92338. eCollection 2024.

Abstract

Triple-negative breast cancer (TNBC) is the most malignant subtype of breast cancer. Breast cancer stem cells (BCSCs) are believed to play a crucial role in the carcinogenesis, therapy resistance, and metastasis of TNBC. It is well known that inflammation promotes stemness. Several studies have identified breast cancer-associated gene 2 (BCA2) as a potential risk factor for breast cancer incidence and prognosis. However, whether and how BCA2 promotes BCSCs has not been elucidated. Here, we demonstrated that BCA2 specifically promotes lipopolysaccharide (LPS)-induced BCSCs through LPS induced SOX9 expression. BCA2 enhances the interaction between myeloid differentiation primary response protein 88 (MyD88) and Toll-like receptor 4 (TLR4) and inhibits the interaction of MyD88 with deubiquitinase OTUD4 in the LPS-mediated NF-κB signaling pathway. And SOX9, an NF-κB target gene, mediates BCA2's pro-stemness function in TNBC. Our findings provide new insights into the molecular mechanisms by which BCA2 promotes breast cancer and potential therapeutic targets for the treatment of breast cancer.

Keywords: BCA2; Breast cancer stem cells; LPS; MyD88; SOX9.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Breast Neoplasms* / genetics
  • Breast Neoplasms* / metabolism
  • Breast Neoplasms* / pathology
  • Cell Line, Tumor
  • Female
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Lipopolysaccharides / pharmacology
  • Myeloid Differentiation Factor 88 / genetics
  • Myeloid Differentiation Factor 88 / metabolism
  • NF-kappa B / metabolism
  • Neoplastic Stem Cells* / metabolism
  • SOX9 Transcription Factor* / genetics
  • SOX9 Transcription Factor* / metabolism
  • Signal Transduction
  • Toll-Like Receptor 4 / genetics
  • Toll-Like Receptor 4 / metabolism
  • Triple Negative Breast Neoplasms / genetics
  • Triple Negative Breast Neoplasms / metabolism
  • Triple Negative Breast Neoplasms / pathology
  • Ubiquitin-Protein Ligases* / genetics
  • Ubiquitin-Protein Ligases* / metabolism
  • Up-Regulation

Substances

  • Lipopolysaccharides
  • Myeloid Differentiation Factor 88
  • NF-kappa B
  • SOX9 protein, human
  • SOX9 Transcription Factor
  • Toll-Like Receptor 4
  • Ubiquitin-Protein Ligases