title: Calpain 2 and PTP1B function in a novel pathway with Src to regulate invadopodia dynamics and breast cancer cell invasion.
abstract: Invasive cancer cells form dynamic adhesive structures associated with matrix degradation called invadopodia. Calpain 2 is a calcium-dependent intracellular protease that regulates adhesion turnover and disassembly through the targeting of specific substrates such as talin. Here, we describe a novel function for calpain 2 in the formation of invadopodia and in the invasive abilities of breast cancer cells through the modulation of endogenous c-Src activity. Calpain-deficient breast cancer cells show impaired invadopodia formation that is rescued by expression of a truncated fragment of protein tyrosine phosphatase 1B (PTP1B) corresponding to the calpain proteolytic fragment, which indicates that calpain modulates invadopodia through PTP1B. Moreover, PTP1B activity is required for efficient invadopodia formation and breast cancer invasion, which suggests that PTP1B may modulate breast cancer progression through its effects on invadopodia. Collectively, our experiments implicate a novel signaling pathway involving calpain 2, PTP1B, and Src in the regulation of invadopodia and breast cancer invasion.
authors.affiliation: Department of Biomolecular Chemistry, University of Wisconsin, Madison, WI 53706, USA.
authors.forename: Christa L
authors.initials: CL
authors.lastname: Cortesio
authors.forename: Keefe T
authors.initials: KT
authors.lastname: Chan
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Perrin
authors.forename: Nicholas O
authors.initials: NO
authors.lastname: Burton
authors.forename: Sheng
authors.initials: S
authors.lastname: Zhang
authors.forename: Zhong-Yin
authors.initials: ZY
authors.lastname: Zhang
authors.forename: Anna
authors.initials: A
authors.lastname: Huttenlocher
mesh_terms: D001943:Breast Neoplasms / Q000378:metabolism* / Q000503:physiopathology; D000081247:CSK Tyrosine-Protein Kinase; D002154:Calpain / Q000235:genetics / Q000378:metabolism*; D002277:Carcinoma / Q000378:metabolism* / Q000503:physiopathology; D002448:Cell Adhesion / Q000502:physiology; D002460:Cell Line; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000502:physiology; D015536:Down-Regulation / Q000235:genetics; D005109:Extracellular Matrix / Q000378:metabolism / Q000648:ultrastructure; D005260:Female; D006801:Humans; D009154:Mutation / Q000235:genetics; D009361:Neoplasm Invasiveness / Q000503:physiopathology*; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1 / Q000235:genetics / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D011554:Pseudopodia / Q000378:metabolism / Q000648:ultrastructure; D015398:Signal Transduction / Q000502:physiology; D019061:src-Family Kinases
chemical_list: D011518:Proto-Oncogene Proteins; D011505:Protein-Tyrosine Kinases; D000081247:CSK Tyrosine-Protein Kinase; D019061:src-Family Kinases; C000631346:CSK protein, human; C516607:PTPN1 protein, human; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; D002154:Calpain; C569870:CAPN2 protein, human