Identification of a microsatellite instability phenotype in meningiomas

To better understand the molecular mechanisms responsible for meningioma tumorigenesis we previously utilized subtractive hybridization protocols to identify genes the expression or structure of which is altered in these common brain tumors. Here we show that a CA dinucleotide repeat element present in one complementary DNA isolated by this approach has undergone a contraction in size in a meningioma cell line. Extension of this initial observation has revealed widespread genetic alterations affecting simple repeat sequences in this and other meningiomas. These data indicate that genetic instability may play a previously unrecognized role in the etiology of meningiomas.