title: Microtubule-associated protein 2 (MAP-2) is expressed in low and high grade diffuse astrocytomas.
abstract: The expression of neuronal antigens in diffuse astrocytomas has not been thoroughly evaluated. We have investigated the expression of microtubule associated protein 2 (MAP-2), synaptophysin and non-phosphorylated epitopes of neurofilament protein (NFP) by immunohistochemistry in 15 low grade diffuse astrocytomas and 15 glioblastomas. MAP-2 was strongly expressed in 97% of cases, using an antibody to both low and high molecular weight isoforms. An antibody specific to high molecular weight isoforms of MAP-2 (hmw-MAP-2) revealed weaker, focal staining in 60% of cases with greater expression in the glioblastomas (P=0.027). NFP was expressed in 50% of cases, but was generally weak and focal. There was little evidence of synaptophysin expression. We conclude that MAP-2 expression in astrocytomas is due predominantly to low molecular weight isoforms, which may be expressed in astrocytes as well as neurons. Focal expression of hmw-MAP-2 and NFP, however, suggest that neuronal antigens may be expressed, particularly in high grade astrocytomas. Immunopositivity for these antigens should not preclude the diagnosis of diffuse astrocytoma.
authors.affiliation: Department of Pathology, University of Edinburgh, Cambridge, UK.
authors.forename: S B
authors.initials: SB
authors.lastname: Wharton
authors.forename: K K
authors.initials: KK
authors.lastname: Chan
authors.forename: I R
authors.initials: IR
authors.lastname: Whittle
mesh_terms: D000328:Adult; D000368:Aged; D001254:Astrocytoma / Q000737:chemistry / Q000378:metabolism*; D005260:Female; D005909:Glioblastoma / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D008297:Male; D008869:Microtubule-Associated Proteins / Q000032:analysis / Q000096:biosynthesis*; D008875:Middle Aged
chemical_list: D008869:Microtubule-Associated Proteins