Figure 5.

A schematic model showing the potential role of HOXA5 in the tumorigenesis of breast cancer. In MCF7 breast cancer cells, the PRC2 complex leads to repressive histone modifications such as H3K27me3 at the putative promoter of HOXA5, resulting in gene expression inhibition. This leads to apoptosis (p53 and p21 expression), epithelial phenotype (E-cadherin expression), and reduced breast cancer stem cell formation (decreased stemness marker expression). On the contrary, in TAMR cells, histone demethylases remove H3K27me3 marks at the HOXA5 putative promoter region. This leads to diminished apoptosis (inhibition of p53 and p21 expression), mesenchymal phenotype (N-cadherin and ZEB1 expression), and enhanced breast cancer stem cell formation (increased stemness marker expression).