Karyotype analyses of 20 human glioma cell lines.

Human malignant gliomas are frequently associated with loss of gonosomes and chromosomes 13, 17, and 22. Their progression from anaplastic glioma to glioblastoma is marked by additional loss of chromosome 10. In addition, structural and numerical aberrations of chromosome 7 are frequently found. We report on the karyotypes of a series of 20 human gliomas of which 11 were analysed as established cell lines; 9 cases were investigated in early culture, 5 of which later also became established 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 present in early cultures as well as in cell lines after various in vitro passages. We found that the general characteristics of karyotypic aberrations found in early cultures or direct preparations of dispersed tumour material were reflected in the pattern of aberrations present in cell lines at much later time points. Thus it appears as if no systematic changes can be attributed to long-term cultures. Suspicious losses of chromosomes 14, 18, and 19 or gain of chromosome 22 indicate that individual cases may have originated due to other mechanisms than the ones already hypothesized, i.e., different suppressor genes or amplification of genes other than the EGF-R-gene. None of the established cell lines had a genomic rearrangement of c-erbB 1, c-erbB 2 or of the p 53 gene.