Fig. 8.

Hypothesis of miR-567 modulation in healthy and BC cells. When miR-567 is expressed, TGF-β, bound to its receptor (two subunits), activates the pathway that leads to the phosphorylation of downstream effectors (i.e., SMAD2 and 3) and to the downregulation of KPN family member. The last effect could be mediated by miR-567 activity. miR-567 could possibly also modulate SMAD4 effector, needed for the transcriptional activation of TGF-β target genes. In aggressive BC cell, TGF-β is upregulated, and the higher activation of its pathway leads to transcription of genes involved in the proliferation control and invasion. The reduction of miR-567 observed in aggressive BC could lead to increase of KPN family members, facilitating the growth of the tumor. TGFβr = TGFβ receptor