KARYOTYPE ANALYSES OF 20 HUMAN GLIOMA CELL-LINES

Human malignant gliomas are frequently associated with loss of gonosom es and chromosomes 13, 17, and 22. Their progression from anaplastic g lioma to glioblastoma is marked by additional loss of chromosome 10. I n addition, structural and numerical aberrations of chromosome 7 are f requently found. We report on the karyotypes of a series of 20 human g liomas of which 11 were analysed as established cell lines; 9 cases we re investigated in early culture, 5 of which later also became establi shed lines. In addition to the frequently reported overrepresentation of chromosome 7, four cell lines with polysomy for chromosome 22 were seen. A high incidence of structural chromosomal aberrations was prese nt in early cultures as well as in cell lines after various in vitro p assages. We found that the general characteristics of karyotypic aberr ations found in early cultures or direct preparations of dispersed tum our material were reflected in the pattern of aberrations present in c ell lines at much later time points. Thus it appears as if no systemat ic changes can be attributed to long-term cultures. Suspicious losses of chromosomes 14, 18, and 19 or gain of chromosome 22 indicate that i ndividual cases may have originated due to other mechanisms than the o nes already hypothesized, i.e., different suppressor genes or amplific ation of genes other than the EGF-R-gene. None of the established cell lines had a genomic rearrangement of c-erbB1, c-erbB2 or of the p 53 gene.