title: The expression of the Nectin complex in human breast cancer and the role of Nectin-3 in the control of tight junctions during metastasis.
abstract: BACKGROUND
  Nectins are a family of integral protein molecules involved in the formation of functioning Adherens and Tight Junctions (TJ). Aberrant expression is associated with cancer progression but little is known how this effects changes in cell behaviour. This study aimed to ascertain the distribution of Nectins-1 to -4 in human breast cancer and the effect on junctional integrity of Nectin-3 modulation in human endothelial and breast cancer cells.
  
  
  METHODS
  A human breast tissue cohort was processed for Q-PCR and immunohistochemistry for analysis of Nectin-1/-2/-3/-4. Nectin-3 over-expression was induced in the human breast cancer cell line MDA-MB-231 and the human endothelial cell line HECV. Functional testing was carried out to ascertain changes in cell behaviour.
  
  
  RESULTS
  Q-PCR revealed a distinct reduction in node positive tumours and in patients with poor outcome. There was increased expression of Nectin-1/-2 in patients with metastatic disease, Nectin-3/-4 was reduced. IHC revealed that Nectin-3 expression showed clear changes in distribution between normal and cancerous cells. Nectin-3 over-expression in MDA-MB-231 cells showed reduced invasion and migration even when treated with HGF. Changes in barrier function resulted in MDAN3 cells showing less change in resistance after 2h treatment with HGF (p<0.001). Nectin-3 transformed endothelial cells were significantly more adhesive, irrespective of treatment with HGF (p<0.05) and had reduced growth. Barrier function revealed that transformed HECV cells had significantly tighter junctions that wildtype cells when treated with HGF (p<0.0001). HGF-induced changes in permeability were also reduced. Overexpression of Nectin-3 produced endothelial cells with significantly reduced ability to form tubules (p<0.0001). Immunoprecipitation studies discovered hitherto novel associations for Nectin-3. Moreover, HGF appeared to exert an effect on Nectin-3 via tyrosine and threonine phosphorylation.
  
  
  CONCLUSIONS
  Nectin-3 may be a key component in the formation of cell junctions and be a putative suppressor molecule to the invasion of breast cancer cells.
authors.affiliation: Cardiff University-Peking University Cancer Research Institute, Cardiff School of Medicine, Cardiff University, Heath Park, Cardiff, United Kingdom.
authors.forename: Tracey A
authors.initials: TA
authors.lastname: Martin
authors.affiliation: Cardiff University-Peking University Cancer Research Institute, Cardiff School of Medicine, Cardiff University, Heath Park, Cardiff, United Kingdom.
authors.forename: Jane
authors.initials: J
authors.lastname: Lane
authors.affiliation: Cardiff University-Peking University Cancer Research Institute, Cardiff School of Medicine, Cardiff University, Heath Park, Cardiff, United Kingdom.
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Harrison
authors.affiliation: Cardiff University-Peking University Cancer Research Institute, Cardiff School of Medicine, Cardiff University, Heath Park, Cardiff, United Kingdom.
authors.forename: Wen G
authors.initials: WG
authors.lastname: Jiang
mesh_terms: D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D045744:Cell Line, Tumor; D005260:Female; D055785:Gene Knockdown Techniques; D006801:Humans; D000075983:Nectins; D009361:Neoplasm Invasiveness / Q000235:genetics; D009362:Neoplasm Metastasis; D010766:Phosphorylation; D019108:Tight Junctions / Q000378:metabolism*
chemical_list: D015815:Cell Adhesion Molecules; C000619010:NECTIN1 protein, human; C000619014:NECTIN3 protein, human; D000075983:Nectins