ALLELIC LOSS AT IP IS ASSOCIATED WITH TUMOR PROGRESSION OF MENINGIOMAS

Next to chromosome 22 anomalies, deletions of the short arm of chromos ome I have previously been described as the most frequent alteration d etected by cytogenetic analysis of meningiomas. To determine the incid ence of these deletions, we have analyzed a series of 50 meningiomas f or the loss of alleles at four chromosome I loci. Thirteen samples dis played LOH for the markers studied; in one instance, the results were compatible with loss of the entire chromosome I, whereas in the other 12 samples deletions of the short arm were observed. Eleven of the men ingiomas had previously been shown to have loss of alleles on chromoso me 22, and 12 of them were characterized by increased tumor aggressive ness. These findings suggest that deletion of Ip (or the alteration of a locus located there) might represent a secondary, but nonrandom alt eration in meningiomas, perhaps contributing to meningioma tumor progr ession. (C) 1994 Wiley-Liss, Inc.