title: The effect of a selective cyclooxygenase-2 (COX-2) inhibitor on the proliferation rate of retinoblastoma cell lines.
abstract: OBJECTIVE
  To examine the effect of nepafenac, a selective cyclooxygenase-2 (COX-2) inhibitor, on the proliferation rate of two human retinoblastoma (Rb)cell lines.
  
  
  METHODS
  Two human Rb cell lines (WERI-RB and Y79) were cultured. COX-2 expression in these cell lines was verified by immunocytochemical analysis of cytospin sections and Western blotting. An MTT-based proliferation assay was used to compare Rb cell growth with and without amfenac, the active metabolite of nepafenac. The averaged results per condition were recorded. The Student's t-test was used to compare results from the cells cultured with and without amfenac.
  
  
  RESULTS
  The Y79 cell line showed a higher proliferative rate than the WERI-RB cell line. Both cell lines were negative for COX-2 expression by immunocytochemical analysis; however, both cell lines were positive for COX-2 expression by Western blot. When amfenac was added to both of the cell lines, a statistically significant reduction in proliferation was observed in both cell lines. The two Rb cell lines were positive for COX-2 only in the Western blot, indicating that they probably express low levels of COX-2, which was undetectable by immunocytochemical analysis.
  
  
  CONCLUSIONS
  The selective, anti-COX-2 molecule amfenac inhibited proliferation of both tested Rb cell lines. Further trials should be undertaken to study the effect of selective COX-2 inhibitors on Rb.
authors.affiliation: The Henry C Witelson Ocular Pathology Laboratory, McGill University, Montreal, Canada. jpessoafilho@hotmail.com
authors.forename: J P
authors.initials: JP
authors.lastname: de Souza Filho
authors.forename: Z M S
authors.initials: ZM
authors.lastname: Correa
authors.forename: J C
authors.initials: JC
authors.lastname: Marshall
authors.forename: E
authors.initials: E
authors.lastname: Anteka
authors.forename: A B
authors.initials: AB
authors.lastname: Coutinho
authors.forename: M C
authors.initials: MC
authors.lastname: Martins
authors.forename: M N
authors.initials: MN
authors.lastname: Burnier
mesh_terms: D015153:Blotting, Western; D049109:Cell Proliferation / Q000187:drug effects; D051546:Cyclooxygenase 2 / Q000378:metabolism; D052246:Cyclooxygenase 2 Inhibitors / Q000494:pharmacology*; D006801:Humans; D010648:Phenylacetates / Q000494:pharmacology*; D019572:Retinal Neoplasms / Q000201:enzymology / Q000473:pathology*; D012175:Retinoblastoma / Q000201:enzymology / Q000473:pathology*; D014407:Tumor Cells, Cultured
chemical_list: D052246:Cyclooxygenase 2 Inhibitors; D010648:Phenylacetates; C014285:amfenac; D051546:Cyclooxygenase 2