DNA AMPLIFICATIONS ON CHROMOSOME-7, CHROMOSOME-9 AND CHROMOSOME-12 INGLIOBLASTOMA DETECTED BY REVERSE CHROMOSOME PAINTING

Biopsies and cell culture, respectively, of four human glioblastoma mu ltiforme (WHO 4) have been evaluated for gene amplification using reve rse chromosome painting. Three of the tumours showed amplified domains within chromosome bands 12q13-15. The exact localisation and extensio n of the amplified domains, however, varies within this region. Southe rn blot analysis revealed amplification of the GLI oncogene in two of the glioblastomas which were found to contain amplified domains within 12q13-15. Reverse chromosome painting also identified amplified domai ns within bands 7q21 and 9p23-24. Amplification within region 9p23-24 has previously not been reported in glioblastoma. The amplified domain encompassing 9p23-24 was detected in the same glioblastoma which cont ained an amplification unit within bands 12q13-14. These data, togethe r with previous reports, indicate that amplifications are predominantl y found on chromosomes 7, 9 and 12 in glioblastoma. In addition, this study provides further evidence that coamplification is not a rare eve nt in glioblastoma.