Comparative genomic hybridization reveals recurrent enhancements on chromosome 20 and in one case combined amplification sites on 15q24q26 and 20p11p12 in glioblastomas

We examined homogenized tissue samples of biopsies from 19 astrocytomas of different grades for genetic imbalances using comparative genomic hybridiza tion ICGN): three astrocytomas grade II, and 16 astrocytomas grade IV (glio blastoma multiforme), one of the glioblastomas representing the recurrence of a benign oligoastrocytoma. In two of three cases of astrocytoma grade II , again of chromosome 7 was found. The alterations in the glioblastomas wer e complex, and most frequently showed the characteristic gain of chromosome 7 and loss of chromosome 10. The single analyzed case Of recurrence Of an oligoastrocytoma was characterized by a unique CGH pattern. This tumor show ed two distinct alterations: apart from an amplification on 15q24q26, we fo und a distinct amplification of a small region on 20p11.2p12, which has not been previously described in brain tumors. Partial or complete gains of ch romosome 20 arose in six other tumors; we conclude that chromosome 20 in pa rticular 20p12.2p12, may harbor relevant genes for glioma progression. (C) 2000 Elsevier Science Inc. All rights reserved.