Meningiomas: analysis of loss of heterozygosity on chromosome 10 in tumor progression and the delineation of four regions of chromosomal deletion in common with other cancers.

PURPOSE Loss of heterozygosity (LOH) of alleles on chromosome 10 has been reported in many cancers, leading to the identification of tumor suppressor genes on this chromosome. Several reports implicate LOH of chromosome 10 alleles in meningioma progression, but the frequency and complexity of the loss have not been well characterized. Furthermore, the location and identity of the putative tumor suppressor genes on this chromosome that contribute to meningioma progression are unknown because the currently characterized tumor suppressor genes do not appear to be involved. Therefore, this study was undertaken to (a) assess the frequency and complexity of LOH in meningioma progression, (b) map the LOH patterns of individual meningiomas to define the smallest regions of shared chromosomal deletion, and (c) compare the identified regions with chromosome 10 deletions in other cancers, and thereby initiate the localization of the putative tumor suppressor genes. EXPERIMENTAL DESIGN We examined 11 microsatellite dinucleotide repeat loci in 208 meningiomas of all grades using laser capture microdissection and fluorescence-based detection of PCR products. RESULTS For all markers examined, the incidence of LOH was much higher in all grades than that previously reported, with incidence and complexity of LOH increasing with tumor grade. LOH mapping identified four regions of chromosomal deletion: 10pter-D10S89, D10S109-D10S215, D10S187-D10S209, and D10S169-10qter. These deletions on chromosome 10 are shared with other cancer types. CONCLUSIONS These results delineate chromosomal locations of putative tumor suppressor genes on chromosome 10 that likely play an early role in meningioma tumorigenesis as well as tumor progression.