title: Maintained CD40 and loss of polarised CD40 ligand expression in oral squamous cell carcinoma.
abstract: BACKGROUND
  CD40 and its ligand (CD40L) are involved in immune response and inhibition or induction of apoptosis in different tissues. Little is known about CD40 and CD40L in oral squamous cell carcinomas (OSCC).
  
  
  METHODS
  CD40 and CD40L were immunohistochemically evaluated in fresh-frozen samples of OSCC (n = 24) and normal oral epithelium (OE, n = 10).
  
  
  RESULTS
  A high proportion of OE-cells expressed CD40 (> 80%) and CD40L (> 90%) in the basal compartment compared to less than 1% CD40-positive and 1% CD40L-positive cells in the suprabasal cell layer, reflecting a zonal distribution. In well-differentiated and moderately-differentiated OSCC, there was a less pronounced zonal distribution of CD40 and a marked loss of CD40L compared to OE (p < 0.05). Poorly-differentiated OSCC maintained CD40 and markedly lost CD40L compared to OE (p < 0.05). Double immunostaining for CD40L and laminin in OE showed a basement membrane associated localisation of CD40L.
  
  
  CONCLUSIONS
  In OSCC, loss of polarised expression of CD40L and maintained expression of CD40 might be involved in tumourigenesis and immune evasion.
authors: Department of Odontology-Oral Pathology and Forensic Odontology, Haukeland University Hospital, University of Bergen, N5021 Bergen, Norway. lado.loro@gades.uib.no
authors: L L
authors: LL
authors: Loro
authors: M
authors: M
authors: Ohlsson
authors: O K
authors: OK
authors: Vintermyr
authors: P G
authors: PG
authors: Liavaag
authors: R
authors: R
authors: Jonsson
authors: A C
authors: AC
authors: Johannessen
mesh_terms: D001485:Basement Membrane / Q000378:metabolism; D019013:CD40 Antigens / Q000378:metabolism*; D023201:CD40 Ligand / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology; D002454:Cell Differentiation; D006801:Humans; D007797:Laminin / Q000378:metabolism; D009061:Mouth Mucosa / Q000378:metabolism; D009062:Mouth Neoplasms / Q000378:metabolism* / Q000473:pathology
chemical_list: D019013:CD40 Antigens; D007797:Laminin; D023201:CD40 Ligand