A Sox2-Sox9 signalling axis maintains human breast luminal progenitor and breast cancer stem cells

Research output: Contribution to journalArticle

  • External authors:
  • Giacomo Domenici
  • Iskander Aurrekoetxea-Rodríguez
  • Miriam Rábano
  • So Young Lee
  • Julia San Millán
  • Valentine Comaills
  • Erik Oliemuller
  • José A López-Ruiz
  • Ignacio Zabalza
  • Beatrice A Howard
  • Robert M Kypta
  • Maria dM Vivanco


Increased cancer stem cell content during development of resistance to tamoxifen in breast cancer is driven by multiple signals, including Sox2-dependent activation of Wnt signalling. Here, we show that Sox2 increases and estrogen reduces the expression of the transcription factor Sox9. Gain and loss of function assays indicate that Sox9 is implicated in the maintenance of human breast luminal progenitor cells. CRISPR/Cas knockout of Sox9 reduces growth of tamoxifen-resistant breast tumours in vivo. Mechanistically, Sox9 acts downstream of Sox2 to control luminal progenitor cell content and is required for expression of the cancer stem cell marker ALDH1A3 and Wnt signalling activity. Sox9 is elevated in breast cancer patients after endocrine therapy failure. This new regulatory axis highlights the relevance of SOX family transcription factors as potential therapeutic targets in breast cancer.

Bibliographical metadata

Original languageEnglish
Early online date8 Jan 2019
Publication statusPublished - 2019