title: The inhibition of the integrin VLA-4 in MV3 melanoma cell binding by non-anticoagulant heparin derivatives.
abstract: BACKGROUND
  The integrin VLA-4-mediated binding is important for the metastatic dissemination of melanoma cells. Recently we found that heparin possesses a binding capacity to VLA-4. This could contribute to the heparin function to attenuate metastasis in a selectin-dependent manner. Aiming to a purposive, anti-adhesive heparin application, structural requirements of heparin for VLA-4 recognition have to be elucidated.
  
  
  METHODS
  A series of non-anticoagulant heparin derivatives were investigated concerning their inhibitory capacities for VLA-4 mediated binding of human melanoma MV3 cells to VCAM-1 under physiological flow conditions in vitro. A surface acoustic wave biosensor was applied to detect kinetic constants of selected derivatives binding to both, VLA-4 or P- and L-selectin.
  
  
  RESULTS
  Experimental metastasis of MV3 cells in mice confirmed the relevance of VLA-4 for metastatic dissemination. LMWHs (enoxaparin, tinzaparin) efficiently blocked VLA-4 cell binding, dominantly via the integrin`s α-chain. Desulfation at 2-O-position, N-acetylation or a size smaller than tetradecasaccharide disfavoured VLA-4 inhibition. Glycol-splitting of heparin and thus higher chain flexibility is a tolerable parameter. A derivative with 50% 6-O-desulfation appeared promising and exceeded tinzaparin in VLA-4 inhibition, both compounds displayed binding affinities to VLA-4 in the low micromolar range.
  
  
  CONCLUSIONS
  These findings provide structure-activity relationships for heparin VLA-4 binding, which partly differ from P- and L-selectin requirements. The data confirm that anti-coagulative and anti-adhesive function of heparin can be distinguished favouring applications of non-anticoagulant heparins in antimetastatic approaches without the risk of bleeding complications. The 50% 6-O-desulfated heparin-derivative appears promising to further evaluate the interference with selectin and VLA-4 binding functions in vivo.
authors.affiliation: Department of Pharmacy, Rheinische Friedrich Wilhelms University Bonn, 53121 Bonn, Germany. mschlesi@gmx.de
authors.forename: Martin
authors.initials: M
authors.lastname: Schlesinger
authors.forename: Patrick
authors.initials: P
authors.lastname: Schmitz
authors.forename: Reiner
authors.initials: R
authors.lastname: Zeisig
authors.forename: Annamaria
authors.initials: A
authors.lastname: Naggi
authors.forename: Giangiacomo
authors.initials: G
authors.lastname: Torri
authors.forename: Benito
authors.initials: B
authors.lastname: Casu
authors.forename: Gerd
authors.initials: G
authors.lastname: Bendas
mesh_terms: D000107:Acetylation; D000818:Animals; D061067:Antibodies, Monoclonal, Humanized / Q000494:pharmacology; D000925:Anticoagulants / Q000378:metabolism* / Q000494:pharmacology; D002448:Cell Adhesion / Q000502:physiology; D045744:Cell Line, Tumor; D004195:Disease Models, Animal; D017984:Enoxaparin / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D005260:Female; D055785:Gene Knockdown Techniques; D006493:Heparin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D006495:Heparin, Low-Molecular-Weight / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D006801:Humans; D039041:Integrin alpha4beta1 / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D008545:Melanoma / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D000069442:Natalizumab; D009362:Neoplasm Metastasis; D034741:RNA, Small Interfering / Q000008:administration & dosage / Q000235:genetics; D013329:Structure-Activity Relationship; D000078222:Tinzaparin; D019010:Vascular Cell Adhesion Molecule-1 / Q000737:chemistry / Q000378:metabolism
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D000925:Anticoagulants; D017984:Enoxaparin; D006495:Heparin, Low-Molecular-Weight; D039041:Integrin alpha4beta1; D000069442:Natalizumab; D034741:RNA, Small Interfering; D019010:Vascular Cell Adhesion Molecule-1; D000078222:Tinzaparin; D006493:Heparin