title: A study of immunoactivity of retinal S-antigen in retinoblastoma.
abstract: OBJECTIVE
  To study retinal S-antigen expression in human retinoblastoma and assess if there is a correlation between S-antigen immunoactivity and degree of retinoblastoma cell differentiations.
  
  
  METHODS
  Ten cases of Chinese retinoblastoma parafin-embedded tissues were applied for this study. A strain of monoclonal antibody,MabA9C6, which defines an epitope in S-antigen retained in fixed-tissue sections, was used to study S-antigen expression in 10 cases of retinoblastomas. S-antigen was localized by the biotinavidin indirect immunoperoxidase technique and purified MabA9C6 ascites fluid was used with 1:100 dilution. The whole procedure could be finished within a few hours.
  
  
  RESULTS
  The S-antigen immunoactivity was observed in different patterns: the "normal" photoreceptor elements incorporated in 3 cases of growing tumors; 3 of 4 Fleurettes and E-W rosettes; and scattered tumor cells in 50% of the cases.
  
  
  CONCLUSIONS
  The result suggests that the expression of S-antigen in retinoblastoma may be used to assess the degree of tumor differentiation as another tumor marker in retinoblastoma.
authors.affiliation: Department of Ophthalmology, 2nd Clinical College, Norman Bethune University of Medical Sciences, Changchun, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Song
authors.forename: G
authors.initials: G
authors.lastname: Yao
authors.forename: C
authors.initials: C
authors.lastname: Fu
mesh_terms: D000941:Antigens / Q000032:analysis*; D019393:Arrestin; D001324:Autoantigens / Q000032:analysis; D014408:Biomarkers, Tumor / Q000032:analysis*; D005134:Eye Neoplasms / Q000276:immunology* / Q000648:ultrastructure; D005136:Eye Proteins / Q000032:analysis*; D006801:Humans; D007150:Immunohistochemistry; D012175:Retinoblastoma / Q000276:immunology* / Q000648:ultrastructure
chemical_list: D000941:Antigens; D019393:Arrestin; D001324:Autoantigens; D014408:Biomarkers, Tumor; D005136:Eye Proteins