myelin-basic-protein and Ear-Neoplasms

ABCA2, which belongs to the A subclass of the ATP-binding cassette (ABC) transporter superfamily, is predominantly expressed in the cytoplasm of oligodendrocytes and Schwann cells, the myelin-forming cells in brain and peripheral nerve, respectively. Here, we demonstrate by immunoblot and immunohistochemistry that ABCA2 is expressed in benign vestibular schwannomas, which contain neither axons nor compact myelin. The expression patterns of ABCA2 in combination with other markers showed phenotypic heterogeneity in schwannomas. The majority of cells in fascicular Antoni type A areas coexpressed ABCA2, Ca2+-binding protein S100beta, and p75 nerve growth factor receptor. In contrast, considerably varied expression levels of ABCA2 and p75 were more prominent in hypocellular type B areas than in type A areas. These data suggest that ABCA2 may be useful as a marker for cellular characterization of schwannomas.

Topics: Adult; ATP-Binding Cassette Transporters; Biomarkers; Ear Neoplasms; Female; Humans; Immunoblotting; Immunohistochemistry; Male; Microscopy, Confocal; Middle Aged; Myelin Basic Protein; Neurofilament Proteins; Neuroma, Acoustic; Peripheral Nerves; Receptor, Nerve Growth Factor; S100 Proteins; Vestibule, Labyrinth

Primary cultures were established from vestibular schwannomas of NF2 patients. The cultured tumor cells were selectively amplified by growth factor supplemented medium and characterized by immunocytochemistry. NF2 cDNA was amplified by RT-PCR and mutations were detected by both the non-isotopic RNase cleavage assay and direct DNA sequencing, no detectable wild-type NF2 transcript was found in cDNA from the cultured cells. Distinguishable morphology and growth rate differences have been observed in different passages of the primary cells. The data suggest that a pure schwannoma primary culture can be established and could be very useful in vitro model for further understanding the NF2 gene function in Schwann cells.

Topics: 2',3'-Cyclic-Nucleotide Phosphodiesterases; Cell Culture Techniques; Cell Division; Ear Neoplasms; Genes, Neurofibromatosis 2; Humans; Myelin Basic Protein; Neurilemmoma; Neurofibromatosis 2; Receptors, Nerve Growth Factor; Sequence Analysis, DNA; Tumor Cells, Cultured; Vestibular Diseases