title: A truncated phosphorylated p130Cas substrate domain is sufficient to drive breast cancer growth and metastasis formation in vivo.
abstract: Elevated p130Cas (Crk-associated substrate) levels are found in aggressive breast tumors and are associated with poor prognosis and resistance to standard therapeutics in patients. p130Cas signals majorly through its phosphorylated substrate domain (SD) that contains 15 tyrosine motifs (YxxP) which recruit effector molecules. Tyrosine phosphorylation of p130Cas is important for mediating migration, invasion, tumor promotion, and metastasis. We previously developed a Src*/SD fusion molecule approach, where the SD is constitutively phosphorylated. In a polyoma middle T-antigen (PyMT)/Src*/SD double-transgenic mouse model, Src*/SD accelerates PyMT-induced tumor growth and promotes a more aggressive phenotype. To test whether Src*/SD also drives metastasis and which of the YxxP motifs are involved in this process, full-length and truncated SD molecules fused to Src* were expressed in breast cancer cells. The functionality of the Src*/SD fragments was analyzed in vitro, and the active proteins were tested in vivo in an orthotopic mouse model. Breast cancer cells expressing the full-length SD and the functional smaller SD fragment (spanning SD motifs 6-10) were injected into the mammary fat pads of mice. The tumor progression was monitored by bioluminescence imaging and caliper measurements. Compared with control animals, the complete SD promoted primary tumor growth and an earlier onset of metastases. Importantly, both the complete and truncated SD significantly increased the occurrence of metastases to multiple organs. These studies provide strong evidence that the phosphorylated p130Cas SD motifs 6-10 (Y236, Y249, Y267, Y287, and Y306) are important for driving mammary carcinoma progression.
authors: Department of Biochemistry, Boston University School of Medicine, 72 E. Concord Street, Boston, MA, 02118, USA.|Department of Medicine III, University Hospital Grosshadern, University of Munich, Munich, Germany.|Institute of Pathology, University of Munich, Munich, Germany.
authors: Joerg
authors: J
authors: Kumbrink
authors: Department of Biochemistry, Boston University School of Medicine, 72 E. Concord Street, Boston, MA, 02118, USA.
authors: Ana
authors: A
authors: de la Cueva
authors: Department of Biochemistry, Boston University School of Medicine, 72 E. Concord Street, Boston, MA, 02118, USA.|The Leona M. and Harry B. Helmsley Charitable Trust, New York, NY, 10169, USA.
authors: Shefali
authors: S
authors: Soni
authors: Department of Biochemistry, Boston University School of Medicine, 72 E. Concord Street, Boston, MA, 02118, USA.|Department of Biochemistry, University of Munich, Munich, Germany.
authors: Nadja
authors: N
authors: Sailer
authors: Department of Biochemistry, Boston University School of Medicine, 72 E. Concord Street, Boston, MA, 02118, USA. kirschk@bu.edu.
authors: Kathrin H
authors: KH
authors: Kirsch
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D001943:Breast Neoplasms / Q000235:genetics / Q000473:pathology*; D000081247:CSK Tyrosine-Protein Kinase; D045744:Cell Line, Tumor; D050719:Crk-Associated Substrate Protein / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D018450:Disease Progression; D005260:Female; D017930:Genes, Reporter; D064593:Heterografts; D006801:Humans; D061986:MCF-7 Cells; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D008822:Mice, Transgenic; D009362:Neoplasm Metastasis; D009363:Neoplasm Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D010446:Peptide Fragments / Q000235:genetics; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000378:metabolism; D000072417:Protein Domains; D011499:Protein Processing, Post-Translational; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D019061:src-Family Kinases / Q000235:genetics / Q000378:metabolism
chemical_list: C493841:BCAR1 protein, human; D050719:Crk-Associated Substrate Protein; D009363:Neoplasm Proteins; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; D019000:Phosphotyrosine; D000081247:CSK Tyrosine-Protein Kinase; D019061:src-Family Kinases; C000631346:CSK protein, human
keywords: Bioluminescence imaging; Breast cancer; Metastasis; Mouse tumor model; Src*/SD; Substrate domain; p130Cas