A COMPARATIVE-STUDY OF GLIOMA CELL-LINES FOR P16, P15, P53 AND P21 GENE ALTERATIONS

A total of 10 glioma cell lines were examined for alterations of the p 16, p15, p53 and p21 genes, which are tumor suppressor genes or candid ates with direct or indirect CDK-inhibitory functions. Genetic alterat ions (deletions or mutations) were frequently seen in the p16, p15 and p53 genes in these cell lines, but not in the p21 gene. When the stat es of the p16, p15 and p53 genes were compared among cell lines, all t he cell lines showed abnormalities in at least 1 gene, often in 2 or 3 genes coincidentally, suggesting that dysfunction of these genes is c losely related to glioma cell growth. Although alteration of all 3 gen es was most frequent, there were cell lines having either p16/p15 or p 53 or p16 and p53 gene alterations, suggesting that the time order of these generic alterations was variable depending on the cell line. Amo ng cell lines examined, one with homozygous p53 gene deletion seemed o f particular practical value, since such a cell line might be useful i n various studies, including investigation of the functions of various mutant p53 genes in the absence of heteromeric protein formation. On examination of the primary tumor tissues, the same alterations of the p16/p15 and p53 genes as detected in the cell lines were demonstrated in all 6 cases examined: p16/p15 gene deletion in 1, p16 gene mutation in 1 and p53 gene mutations in 5 cases, This suggested that the p16/p 15 and the p53 gene alterations and their combinations in at least som e glioma cell lines reflected those in the primary glioma tissues.