Rod cell-specific antigens in retinoblastoma
T. Vrabec, V. Arbizo, G. Adamus, J. H. McDowell, P. A. Hargrave and L. A. Donoso
Retina Service, Wills Eye Hospital, Philadelphia, PA 19107.
We investigated rhodopsin immunoreactivity in five well-differentiated
retinoblastomas using a panel of monoclonal antibodies directed against
specific antigenic sites in the amino- and carboxyl-terminal portions of
rhodopsin. All five monoclonal antibodies bound to the rod cell outer
segment of nontumorous retina in all 10% formaldehyde solution-fixed,
paraffin-embedded tissue sections. A characteristic "halo" cell surface
staining pattern was observed in four (80%) of five tumors treated with two
monoclonal antibodies, B6-30 (rhodopsin amino-terminal specific) and
K16-107 (rhodopsin carboxyl-terminal specific). In each case, the staining
pattern was limited to well-differentiated areas of the tumor containing
Flexner-Wintersteiner rosettes or fleurettes. One tumor was not stained by
any monoclonal antibody, whereas all monoclonal antibodies stained the rod
cell outer segments of nontumorous retina. Our studies indicate that
selected retinoblastomas may be differentiated along a rod
photoreceptorlike cell lineage.
