title: Bay11-7082 inhibits the disintegration of the lymphendothelial barrier triggered by MCF-7 breast cancer spheroids; the role of ICAM-1 and adhesion.
abstract: BACKGROUND
  Many cancers spread through lymphatic routes, and mechanistic insights of tumour intravasation into the lymphatic vasculature and targets for intervention are limited. The major emphasis of research focuses currently on the molecular biology of tumour cells, while still little is known regarding the contribution of lymphatics.
  
  
  METHODS
  Breast cancer cell spheroids attached to lymphendothelial cell (LEC) monolayers were used to investigate the process of intravasation by measuring the areas of 'circular chemorepellent-induced defects' (CCID), which can be considered as entry gates for bulky tumour intravasation. Aspects of tumour cell intravasation were furthermore studied by adhesion assay, and siRNA-mediated knockdown of intracellular adhesion molecule-1 (ICAM-1). Replacing cancer spheroids with the CCID-triggering compound 12(S)-hydroxyeicosatetraenoic acid (HETE) facilitated western blot analyses of Bay11-7082- and baicalein-treated LECs.
  
  
  RESULTS
  Binding of LECs to MCF-7 spheroids, which is a prerequisite for CCID formation, was mediated by ICAM-1 expression, and this depended on NF-κB and correlated with the expression of the prometastatic factor S100A4. Simultaneous inhibition of NF-κB with Bay11-7082 and of arachidonate lipoxygenase (ALOX)-15 with baicalein prevented CCID formation additively.
  
  
  CONCLUSIONS
  Two mechanisms contribute to CCID formation: ALOX15 via the generation of 12(S)-HETE by MCF-7 cells, which induces directional migration of LECs, and ICAM-1 in LECs under control of NF-κB, which facilitates adhesion of MCF-7 cells to LECs.
authors.affiliation: Institute of Clinical Pathology, Medical University of Vienna, Vienna, Austria.
authors.forename: K
authors.initials: K
authors.lastname: Viola
authors.forename: S
authors.initials: S
authors.lastname: Kopf
authors.forename: N
authors.initials: N
authors.lastname: Huttary
authors.forename: C
authors.initials: C
authors.lastname: Vonach
authors.forename: N
authors.initials: N
authors.lastname: Kretschy
authors.forename: M
authors.initials: M
authors.lastname: Teichmann
authors.forename: B
authors.initials: B
authors.lastname: Giessrigl
authors.forename: I
authors.initials: I
authors.lastname: Raab
authors.forename: S
authors.initials: S
authors.lastname: Stary
authors.forename: S
authors.initials: S
authors.lastname: Krieger
authors.forename: T
authors.initials: T
authors.lastname: Keller
authors.forename: S
authors.initials: S
authors.lastname: Bauer
authors.forename: B
authors.initials: B
authors.lastname: Hantusch
authors.forename: T
authors.initials: T
authors.lastname: Szekeres
authors.forename: R
authors.initials: R
authors.lastname: de Martin
authors.forename: W
authors.initials: W
authors.lastname: Jäger
authors.forename: W
authors.initials: W
authors.lastname: Mikulits
authors.forename: H
authors.initials: H
authors.lastname: Dolznig
authors.forename: G
authors.initials: G
authors.lastname: Krupitza
authors.forename: M
authors.initials: M
authors.lastname: Grusch
mesh_terms: D015153:Blotting, Western; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D002448:Cell Adhesion / Q000187:drug effects*; D002465:Cell Movement; D002633:Chemotaxis / Q000187:drug effects; D004729:Endothelium, Lymphatic / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D016328:NF-kappa B / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D009570:Nitriles / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018874:Spheroids, Cellular / Q000187:drug effects*; D013450:Sulfones / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: C434003:3-(4-methylphenylsulfonyl)-2-propenenitrile; D016328:NF-kappa B; D009570:Nitriles; D012333:RNA, Messenger; D013450:Sulfones; D018799:Intercellular Adhesion Molecule-1