title: Genetic and epigenetic alteration of the NF2 gene in sporadic meningiomas.
abstract: The role of the NF2 gene in the development of meningiomas has recently been documented; inactivating mutations plus allelic loss at 22q, the site of this gene (at 22q12), have been identified in both sporadic and neurofibromatosis type 2-associated tumors. Although epigenetic inactivation through aberrant CpG island methylation of the NF2 5' flanking region has been documented in schwannoma (another NF2-associated neoplasm), data on participation of this epigenetic modification in meningiomas are not yet widely available. Using methylation-specific PCR (MSP) plus sequencing, we assessed the presence of aberrant promoter NF2 methylation in a series of 88 meningiomas (61 grade I, 24 grade II, and 3 grade III), in which the allelic constitution at 22q and the NF2 mutational status also were determined by RFLP/microsatellite and PCR-SSCP analyses. Chromosome 22 allelic loss, NF2 gene mutation, and aberrant NF2 promoter methylation were detected in 49%, 24%, and 26% of cases, respectively. Aberrant NF2 methylation with loss of heterozygosity (LOH) at 22q was found in five cases, and aberrant methylation with NF2 mutation in another; LOH 22q and the mutation were found in 16 samples. The aberrant methylation of the NF2 gene also was the sole alteration in 15 samples, most of which were from grade I tumors. These results indicate that aberrant NF2 hypermethylation may participate in the development of a significant proportion of sporadic meningiomas, primarily those of grade I.
authors.affiliation: Laboratorio de Oncogenética Molecular y Epigenética del Cáncer, Departamento de C. Experimental, Unidad de Investigación, Hospital Universitario La Paz, Madrid, Spain.
authors.forename: Jesus
authors.initials: J
authors.lastname: Lomas
authors.forename: M Josefa
authors.initials: MJ
authors.lastname: Bello
authors.forename: Dolores
authors.initials: D
authors.lastname: Arjona
authors.forename: M Eva
authors.initials: ME
authors.lastname: Alonso
authors.forename: Victor
authors.initials: V
authors.lastname: Martinez-Glez
authors.forename: Isabel
authors.initials: I
authors.lastname: Lopez-Marin
authors.forename: Cinthia
authors.initials: C
authors.lastname: Amiñoso
authors.forename: Jose M
authors.initials: JM
authors.lastname: de Campos
authors.forename: Alberto
authors.initials: A
authors.lastname: Isla
authors.forename: Jesus
authors.initials: J
authors.lastname: Vaquero
authors.forename: Juan A
authors.initials: JA
authors.lastname: Rey
mesh_terms: D002869:Chromosome Aberrations; D002892:Chromosomes, Human, Pair 22; D018899:CpG Islands; D019175:DNA Methylation; D016515:Genes, Neurofibromatosis 2 / Q000502:physiology*; D006801:Humans; D019656:Loss of Heterozygosity; D008577:Meningeal Neoplasms / Q000235:genetics*; D008579:Meningioma / Q000235:genetics*; D018895:Microsatellite Repeats; D009154:Mutation; D018807:Polymorphism, Single-Stranded Conformational; D011401:Promoter Regions, Genetic / Q000235:genetics