title: Association of CD47 with natural killer cell-mediated cytotoxicity of head-and-neck squamous cell carcinoma lines.
abstract: OBJECTIVE
  Integrin-associated protein (CD47) binds specifically to the inhibitory receptor signal-regulatory protein. This study was designed to evaluate the role of CD47 in natural killer (NK) cell-mediated cytotoxicity against cancer cells.
  
  
  METHODS
  Head-and-neck squamous cell carcinoma (HNSCC) cell lines were analyzed for the expression of CD47 and susceptibility to NK cell-mediated killing. Cytolytic activity was assessed by (51)Cr-specific release assays and by measuring cytokine production.
  
  
  RESULTS
  HNSCC cell lines that had high CD47 expression showed lower levels of NK cytotoxicity than those with low CD47 expression. After pre-treating cells with neutralizing major histocompatibility complex (MHC) class I or anti-CD47 antibodies, NK cell-mediated cytotoxicity against HNSCC cell lines increased. In addition, when CD47 cDNA was transfected into Caco-2 cells, NK cell-mediated cytotoxicity decreased.
  
  
  CONCLUSIONS
  These findings suggest that CD47 may play an inhibitory role in NK cell-mediated cytotoxicity against cancer cells, implying a possible mechanism of immune escape in human cancer.
authors.affiliation: Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Min Jung
authors.initials: MJ
authors.lastname: Kim
authors.forename: June-Chul
authors.initials: JC
authors.lastname: Lee
authors.forename: Jae-Jung
authors.initials: JJ
authors.lastname: Lee
authors.forename: Soyeon
authors.initials: S
authors.lastname: Kim
authors.forename: Sang Goo
authors.initials: SG
authors.lastname: Lee
authors.forename: Seok-Woo
authors.initials: SW
authors.lastname: Park
authors.forename: Myung Whun
authors.initials: MW
authors.lastname: Sung
authors.forename: Dae Seog
authors.initials: DS
authors.lastname: Heo
mesh_terms: D051928:CD47 Antigen / Q000235:genetics / Q000276:immunology*; D002294:Carcinoma, Squamous Cell / Q000276:immunology*; D045744:Cell Line, Tumor; D003602:Cytotoxicity, Immunologic; D006258:Head and Neck Neoplasms / Q000276:immunology*; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D014162:Transfection
chemical_list: D051928:CD47 Antigen; C497894:CD47 protein, human