title: Analysis of the  role of hMLH1 hypermethylation and microsatellite instability in meningioma  progression.
abstract: We  investigated a possible role of hMLH1 hypermethylation and microsatellite  instability in meningioma progression. Fifty meningomas were examined for  methylation of hMLH1 using a methylation-specific PCR; 43 of them were  analyzed for microsatellite instability using nine microsatellite markers.  Loss of heterozygosity on chromosome 22q was detected using two markers. Two  atypical meningiomas showed microsatellite instability at four loci; one was  methylated on hMLH1 and the other was unmethylated. Nine meningiomas were  found to have methylated hMLH1; the frequencies in the different grades of  meningioma were one of 20, two of 16, and six of 14, respectively. We  concluded that the methylation status of hMLH1 is associated with the  meningioma grade but not with microsatellite instability. Loss of  heterozygosity was detected in 22 cases in at least one marker. The frequency  of loss of heterozygosity increased with meningioma grade, but the tendency was  not significant. The correlation between loss of heterozygosity and methylation  of the hMLH1 gene was also not significant. We conclude that hypermethylation  of the promoter of hMLH1 is an epigenetic change in meningiomas and is  associated with the tumor grade, while microsatellite instability is an  uncommon event in meningiomas.
authors.affiliation: The State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China.
authors.forename: M N
authors.initials: MN
authors.lastname: Chen
authors.forename: P
authors.initials: P
authors.lastname: Wang
authors.forename: J
authors.initials: J
authors.lastname: Zhang
authors.forename: B Y
authors.initials: BY
authors.lastname: Zhou
authors.forename: Q
authors.initials: Q
authors.lastname: Mao
authors.forename: Y H
authors.initials: YH
authors.lastname: Liu
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics* / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics; D019175:DNA Methylation / Q000235:genetics*; D018450:Disease Progression; D005260:Female; D056426:Genetic Loci / Q000235:genetics; D006801:Humans; D019656:Loss of Heterozygosity / Q000235:genetics; D008297:Male; D008577:Meningeal Neoplasms / Q000235:genetics* / Q000473:pathology*; D008579:Meningioma / Q000235:genetics* / Q000473:pathology*; D053842:Microsatellite Instability; D008875:Middle Aged; D000070957:MutL Protein Homolog 1; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D016133:Polymerase Chain Reaction; D055815:Young Adult
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C501486:MLH1 protein, human; D009687:Nuclear Proteins; D000070957:MutL Protein Homolog 1