Neuron-associated class III beta-tubulin isotype, microtubule-associated protein 2, and synaptophysin in human retinoblastomas in situ. Further immunohistochemical observations on the Flexner-Wintersteiner rosettes.
We studied by immunohistochemistry 26 retinoblastomas in situ using monoclonal antibodies specific for the neuron-associated class III beta-tubulin isotype (h beta 4), microtubule-associated protein 2 (MAP2), and synaptophysin. Anti-h beta 4 and anti-MAP2 immunostaining was consistently obtained in the Flexner-Wintersteiner rosettes, in fleurettes, in Homer Wright (neuroblastic) rosettes, and also variably among poorly differentiated tumor cells. A similar pattern of antisynaptophysin immunopositivity was seen, but was especially pronounced in the adluminal borders of cells forming the Flexner-Wintersteiner rosettes. The demonstration of h beta 4, MAP2, and synaptophysin epitopes in poorly differentiated and maturing neoplastic phenotypes in retinoblastomas attests to the neuronal character of this embryonal tumor. Immunoreactivity toward h beta 4 and MAP2 epitopes by poorly differentiated neoplastic cells may indicate early neuronal commitment in retinoblastoma. The consistent immunostaining of Flexner-Wintersteiner rosettes with monoclonal antibodies to h beta 4 and MAP2 is in keeping with the previous ultrastructural documentation of microtubules with a neuronal-like spatial organization present in the cells of these structures.
Katsetos
C D
CD
Department of Pathology (Neuropathology), University of Virginia, Charlottesville.
Herman
M M
MM
Frankfurter
A
A
Uffer
S
S
Perentes
E
E
Rubinstein
L J
LJ
D000328:Adult; D002454:Cell Differentiation; D000939:Epitopes; D005134:Eye Neoplasms / Q000378:metabolism* / Q000473:pathology; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D007231:Infant, Newborn; D008297:Male; D008565:Membrane Proteins / Q000276:immunology / Q000378:metabolism*; D008869:Microtubule-Associated Proteins / Q000276:immunology / Q000378:metabolism*; D008875:Middle Aged; D009474:Neurons / Q000378:metabolism*; D012160:Retina / Q000166:cytology / Q000378:metabolism; D012175:Retinoblastoma / Q000378:metabolism* / Q000473:pathology; D013194:Staining and Labeling; D016708:Synaptophysin; D014404:Tubulin / Q000276:immunology / Q000378:metabolism*
D000939:Epitopes; D005904:Glial Fibrillary Acidic Protein; D008565:Membrane Proteins; D008869:Microtubule-Associated Proteins; D016708:Synaptophysin; D014404:Tubulin