Inhibition of breast tumor stem cells expansion by the endogenous cell fate determination factor dachshund

Abstract

The Dachshund homolog 1 (Dach1) gene encodes a conserved co-repressor protein that, through its interaction with other nuclear proteins in the context of the local chromatin, participates in the regulation of genes essential for precursor cell proliferation and survival. DACH1 has been implicated in breast, prostate, ovarian and endometrial tumorigenesis. In breast cancer, reduced expression of DACH1 correlates with poor prognosis. Analysis of the mechanisms involved discovered that DACH1 binds and represses a subset of genes with important functions in tumorigenesis and tumor progression. By inhibiting chemokine expression, DACH1 reduces cellular migration, invasion, and metastatic capability of breast cancer cells. DACH1 also represses several AP-1-responsive genes, including the cell cycle regulator Cyclin D1. Recent studies demonstrated that endogenous DACH1 targets key regulators of stem cell identity in breast cancer cells. The present chapter summarizes the evidence that DACH1 regulates breast tumor progression and cancer stem cell expansion. We discuss the mechanisms involved.