[HTML][HTML] β4 integrin amplifies ErbB2 signaling to promote mammary tumorigenesis

W Guo, Y Pylayeva, A Pepe, T Yoshioka, WJ Muller… - Cell, 2006 - cell.com
W Guo, Y Pylayeva, A Pepe, T Yoshioka, WJ Muller, G Inghirami, FG Giancotti
Cell, 2006cell.com
Amplification of the ErbB2 locus, which encodes a receptor tyrosine kinase, is common in
aggressive breast tumors and correlates with poor prognosis. The mechanisms underlying
ErbB2-mediated breast carcinoma progression remain incompletely defined. To examine
the role of the signaling and cell-adhesion receptor β4 integrin during ErbB2-mediated
tumorigenesis, we introduced a targeted deletion of the β4 signaling domain into a mouse
model of ErbB2-induced mammary carcinoma. Loss of β4 signaling suppresses mammary …
Summary
Amplification of the ErbB2 locus, which encodes a receptor tyrosine kinase, is common in aggressive breast tumors and correlates with poor prognosis. The mechanisms underlying ErbB2-mediated breast carcinoma progression remain incompletely defined. To examine the role of the signaling and cell-adhesion receptor β4 integrin during ErbB2-mediated tumorigenesis, we introduced a targeted deletion of the β4 signaling domain into a mouse model of ErbB2-induced mammary carcinoma. Loss of β4 signaling suppresses mammary tumor onset and invasive growth. Ex vivo studies indicate that β4 forms a complex with ErbB2 and enhances activation of the transcription factors STAT3 and c-Jun. STAT3 contributes to disruption of epithelial adhesion and polarity, while c-Jun is required for hyperproliferation. Finally, deletion of the β4 signaling domain enhances the efficacy of ErbB2-targeted therapy. These results indicate that β4 integrin promotes tumor progression by amplifying ErbB2 signaling and identify β4 as a potential target for molecular therapy of breast cancer.
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