The effect of a selective cyclooxygenase-2 (COX-2) inhibitor on the proliferation rate of retinoblastoma cell lines.
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.
de Souza Filho
J P
JP
The Henry C Witelson Ocular Pathology Laboratory, McGill University, Montreal, Canada. jpessoafilho@hotmail.com
Correa
Z M S
ZM
Marshall
J C
JC
Anteka
E
E
Coutinho
A B
AB
Martins
M C
MC
Burnier
M N
MN
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
D052246:Cyclooxygenase 2 Inhibitors; D010648:Phenylacetates; C014285:amfenac; D051546:Cyclooxygenase 2