Differential expression of cell adhesion molecules (CAM), neural CAM and epithelial cadherin in ependymomas and choroid plexus tumors.
A series of frozen specimens of 18 ependymomas and 7 choroid plexus tumors were examined for their expression of cell adhesion molecules, such as neural cell adhesion molecule (NCAM), its polysialylated isoforms (PSA NCAM), and epithelial (E-) cadherin, and of intermediate filament proteins, such as glial fibrillary acidic protein (GFAP) and cytokeratin, using various monoclonal and polyclonal antibodies. Normal choroid plexus and ependyma were taken as controls. Anti-E-cadherin immunoreactivity was observed on the basolateral part of most adult choroid plexus and benign choroid plexus papilloma cells. However, a small number of atypical papillomas and carcinoma cells showed anti- E-cadherin immunoreactivity throughout their cell surface membrane. NCAM were not expressed by adult choroid plexus and benign papilloma cells. Only a few cells expressed NCAM and PSA NCAM in developing choroid plexus, atypical papillomas and carcinomas. Cytokeratin expression was always observed in choroid plexus and their tumors; GFAP expression was variable from case to case. In contrast, ependymal cells and their tumors never expressed E-cadherin but strongly expressed NCAM. PSA NCAM was found in ependymomas exhibiting anaplastic features. All ependymomas strongly expressed GFAP and a few demonstrated slight expression of cytokeratin. These data suggest that, besides GFAP and cytokeratin, NCAM and E-cadherin are of potential diagnostic value in distinguishing choroid plexus tumors from ependymomas. E-cadherin and NCAM may play a role in the functional organization of normal choroid plexus and ependyma, respectively. In particular, incomplete or irregular anti-E-cadherin expression in choroid plexus tumors and PSA NCAM immunoreativity in ependymomas and choroid plexus tumors correlates with the emergence of anaplastic histological features.
Figarella-Branger
D
D
Laboratoire de Biopathologie Nerveuse et Musculaire, Faculté de Médecine, Marseille, France.
Lepidi
H
H
Poncet
C
C
Gambarelli
D
D
Bianco
N
N
Rougon
G
G
Pellissier
J F
JF
D000293:Adolescent; D000328:Adult; D000368:Aged; D015153:Blotting, Western; D015820:Cadherins / Q000378:metabolism*; D002420:Cauda Equina; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D015816:Cell Adhesion Molecules, Neuronal / Q000378:metabolism; D002551:Cerebral Ventricle Neoplasms / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D016545:Choroid Plexus Neoplasms / Q000378:metabolism*; D004806:Ependymoma / Q000378:metabolism*; D004848:Epithelium / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D010524:Peripheral Nervous System Neoplasms / Q000378:metabolism*
D015820:Cadherins; D015815:Cell Adhesion Molecules; D015816:Cell Adhesion Molecules, Neuronal