FREQUENT DELETIONS OF MATERIAL FROM CHROMOSOME ARM IP IN OLIGODENDROGLIAL TUMORS REVEALED BY DOUBLE-TARGET FLUORESCENCE IN-SITU HYBRIDIZATION AND MICROSATELLITE ANALYSIS

We undertook a cytogenetic analysis of 29 human brain tumors using dou ble-target fluorescence in situ hybridization (FISH) and focusing on c hromosome arm 1p. One or more tumor suppressor genes in this arm have been suggested to be important in a variety of neuroectodermal tumors, The series included 9 oligodendrogliomas, 4 mixed gliomas, 10 astrocy tomas, 4 glioblastomas, and 2 central neurocytomas. We hybridized peri centromeric (1q12) and subtelomeric (1p36) DNA probes to cell nuclei p repared from paraffin-embedded tissues and observed a strikingly high incidence of deletion of at least part of 1p in oligodendrogliomas (10 0%) and mixed gliomas (75%). The results of the FISH analyses were con firmed by demonstration of loss of heterozygosity for a microsatellite polymorphism in 10 of the 29 tumors. As well as supporting the feasib ility of FISH for detecting allelic deletions in chromosomes from para ffin-embedded tumor samples, the alteration of 1p reported here will c ontribute to an understanding of the molecular genetic events in oligo dendroglial tumor development. (C) 1995 Wiley-Liss, Inc.