An EGFR-Src-Arg-cortactin pathway mediates functional maturation of invadopodia and breast cancer cell invasion.

Abstract

Invasive carcinoma cells use specialized actin polymerization-driven protrusions called invadopodia to degrade and possibly invade through the extracellular matrix (ECM) during metastasis. Phosphorylation of the invadopodium protein cortactin is a master switch that activates invadopodium maturation and function. Cortactin was originally identified as a hyperphosphorylated protein in v-Src-transformed cells, but the kinase or kinases that are directly responsible for cortactin phosphorylation in invadopodia remain unknown. In this study, we provide evidence that the Abl-related nonreceptor tyrosine kinase Arg mediates epidermal growth factor (EGF)-induced cortactin phosphorylation, triggering actin polymerization in invadopodia, ECM degradation, and matrix proteolysis-dependent tumor cell invasion. Both Src and Arg localize to invadopodia and are required for EGF-induced actin polymerization. Notably, Arg overexpression in Src knockdown cells can partially rescue actin polymerization in invadopodia while Src overexpression cannot compensate for loss of Arg, arguing that Src indirectly regulates invadopodium maturation through Arg activation. Our findings suggest a novel mechanism by which an EGFR-Src-Arg-cortactin pathway mediates functional maturation of invadopodia and breast cancer cell invasion. Furthermore, they identify Arg as a novel mediator of invadopodia function and a candidate therapeutic target to inhibit tumor invasion in vivo.

• Authors: Christopher C Mader, Matthew Oser, Marco A O Magalhaes, Jose Javier Bravo-Cordero, John Condeelis, Anthony J Koleske, Hava Gil-Henn
• Journal: Cancer research (Cancer Res) Vol. 71 Issue 5 Pg. 1730-41 (Mar 01 2011) ISSN: 1538-7445 [Electronic] United States
• PMID: 21257711 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)
• Copyright: ©2011 AACR.

Chemical References

• Cortactin
• ARG tyrosine kinase
• ErbB Receptors
• Protein-Tyrosine Kinases
• src-Family Kinases

Topics

• Animals
• Blotting, Western
• Breast Neoplasms (metabolism, pathology)
• Cortactin (metabolism)
• ErbB Receptors (metabolism)
• Extracellular Matrix (metabolism)
• Female
• Fluorescent Antibody Technique
• Humans
• Immunoprecipitation
• Mice
• Neoplasm Invasiveness
• Phosphorylation
• Protein-Tyrosine Kinases (metabolism)
• Pseudopodia (metabolism)
• Rats
• Signal Transduction
• src-Family Kinases (metabolism)