title: Specific syndecan-1 domains regulate mesenchymal tumor cell adhesion, motility and migration.
abstract: BACKGROUND
  Syndecans are proteoglycans whose core proteins have a short cytoplasmic domain, a transmembrane domain and a large N-terminal extracellular domain possessing glycosaminoglycan chains. Syndecans are involved in many important cellular processes. Our recent publications have demonstrated that syndecan-1 translocates into the nucleus and hampers tumor cell proliferation. In the present study, we aimed to investigate the role of syndecan-1 in tumor cell adhesion and migration, with special focus on the importance of its distinct protein domains, to better understand the structure-function relationship of syndecan-1 in tumor progression.
  
  
  RESULTS
  We utilized two mesenchymal tumor cell lines which were transfected to stably overexpress full-length syndecan-1 or truncated variants: the 78 which lacks the extracellular domain except the DRKE sequence proposed to be essential for oligomerization, the 77 which lacks the whole extracellular domain, and the RMKKK which serves as a nuclear localization signal. The deletion of the RMKKK motif from full-length syndecan-1 abolished the nuclear translocation of this proteoglycan. Various bioassays for cell adhesion, chemotaxis, random movement and wound healing were studied. Furthermore, we performed gene microarray to analyze the global gene expression pattern influenced by syndecan-1. Both full-length and truncated syndecan-1 constructs decrease tumor cell migration and motility, and affect cell adhesion. Distinct protein domains have differential effects, the extracellular domain is more important for promoting cell adhesion, while the transmembrane and cytoplasmic domains are sufficient for inhibition of cell migration. Cell behavior seems to depend also on the nuclear translocation of syndecan-1. Many genes are differentially regulated by syndecan-1 and a number of genes are actually involved in cell adhesion and migration.
  
  
  CONCLUSIONS
  Our results demonstrate that syndecan-1 regulates mesenchymal tumor cell adhesion and migration, and different domains have differential effects. Our study provides new insights into better understanding of the role of syndecans in tumor progression.
authors: Division of Pathology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden. Fang.Zong@ki.se
authors: Fang
authors: F
authors: Zong
authors: Eleni
authors: E
authors: Fthenou
authors: Filip
authors: F
authors: Mundt
authors: Tünde
authors: T
authors: Szatmári
authors: Ilona
authors: I
authors: Kovalszky
authors: László
authors: L
authors: Szilák
authors: David
authors: D
authors: Brodin
authors: George
authors: G
authors: Tzanakakis
authors: Anders
authors: A
authors: Hjerpe
authors: Katalin
authors: K
authors: Dobra
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D002448:Cell Adhesion / Q000235:genetics; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics; D002467:Cell Nucleus / Q000378:metabolism; D002633:Chemotaxis / Q000235:genetics; D005434:Flow Cytometry; D006801:Humans; D008648:Mesoderm / Q000378:metabolism* / Q000473:pathology*; D008969:Molecular Sequence Data; D019913:Nuclear Localization Signals / Q000737:chemistry / Q000378:metabolism; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D017384:Sequence Deletion / Q000235:genetics; D013329:Structure-Activity Relationship; D053668:Syndecan-1 / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D019913:Nuclear Localization Signals; D053668:Syndecan-1