COMPARATIVE GENOMIC HYBRIDIZATION OF HUMAN-MALIGNANT GLIOMAS REVEALS MULTIPLE AMPLIFICATION SITES AND NONRANDOM CHROMOSOMAL GAINS AND LOSSES

Nine human malignant gliomas (2 astrocytomas grade III and 7 glioblast omas) were analyzed using comparative genomic hybridization (CGH). lit addition to the amplification of the EGFR gene at 7p12 in 4 of 9 case s, six new amplification sites were mapped to 1q32, 4q12, 7q21.1, 7q21 .2-3, 12p, and 22q12. Nonrandom chromosomal gains and losses were iden tified with overrepresentation of chromosome 7 and underrepresentation of chromosome 10 as the most frequent events (1 of 2 astrocytomas, 7 of 7 glioblastomas). Gain of a part or the whole chromosome 19 and los ses of chromosome bands 9pter-23 and 22q13 were detected each in five cases. Loss of chromosome band 17p13 and gain of chromosome 20 were re vealed each in three cases. The validity of the CGH data was confirmed using interphase cytogenetics with YAC clones, chromosome painting il l tumor metaphase spreads, and DNA finger-printing. A comparison of CG H data with the results of chromosome banding analyses indicates that metaphase spreads accessible in primary tumor cell cultures may not re present the clones predominant in the tumor tissue.