A Comparative Study of Glioma Cell Lines for p16, p15, p53 and p21 Gene Alterations

Abstract

A total of 10 glioma cell lines were examined for alterations of the p16, p15, p53 and p21 genes, which are tumor suppressor genes or candidates with direct or indirect CDK‐inhibitory functions. Genetic alterations (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 states of the p16, p15 and p53 genes were compared among cell lines, all the cell lines showed abnormalities in at least 1 gene, often in 2 or 3 genes coincidentally, suggesting that dysfunction of these genes is closely related to glioma cell growth. Although alteration of all 3 genes was most frequent, there were cell lines having either p16/p15 or p53 or p16 and p53 gene alterations, suggesting that the time order of these genetic alterations was variable depending on the cell line. Among cell lines examined, one with homozygous p53 gene deletion seemed of particular practical value, since such a cell line might be useful in 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/p15 and the p53 gene alterations and their combinations in at least some glioma cell lines reflected those in the primary glioma tissues.

Transforming Growth Factor-β-mediated p15INK4BInduction and Growth Inhibition in Astrocytes Is SMAD3-dependent and a Pathway Prominently Altered in Human Glioma Cell Lines

“…Through Southern blot analysis, we demonstrated that the p15 INK4B gene has been deleted in the majority of those glioma lines, a result consistent with previous findings (41)(42)(43)(44). Only two glioma cell lines (T98G and D423MG) retained p15 INK4B expression, and TGF-␤ mildly induced further expression.…”

Identification of genomic DNA sequences bound by mutant p53 protein (Gly245→Ser) in vivo

“…After linker ligation and ampli®cation by linker-speci®c PCR, the DNA fragments were cloned into plasmid pCRII, and then screened for mut p53 speci®c binding by PCR-EMSA (for details see legend to Figure 1). As cell line for in vivo cross-linking of mut p53 we chose the human tumor-derived glioma cell line Onda 11 Zhang et al, 1996), which expresses a nuclear mut p53 with the amino acid exchange Gly 245 ?Ser. Gly 245 is located within the L3 loop of the p53 DNA binding domain, which provides major and minor groove contacts with the p53 consensus-DNA element (Cho et al, 1994).…”

“…To con®rm the speci®c binding of mut p53 to those DNA fragments by a di erent experimental approach and to mimic the in vivo interaction between the mut Zhang et al, 1996)) were cultured in DMEM plus 10% FCS to 80% con¯uence. Then the medium was replaced with fresh medium containing 1 mM cisplatin and cultured for further 2 h. Cisplatin-treated cells were washed with KM bu er (pH 6.8; 10 mM NaCl, 1.5 mM MgCl2, 1 mM EGTA, 5 mM dithiothreitol, 10% glycerol, 10 mM morpholinepropanesulfonic acid [MOPS]) and lysed for 30 min on ice in KM bu er containing 1% NonidetP-40 (NP-40) and proteinase inhibitors (5 mg/ml leupeptin, 1 mg/ml pepstatin, 2 mM PMSF, 1% Trasylol).…”

Rare‐type Mutations of MMAC1 Tumor Suppressor Gene in Human Glioma Cell Lines and Their Tumors of Origin

“…Nine (cases 1-6 and 8-10) had been established in our institute [25][26][27][28] and the other was U-251MG (case 7).…”

“…Nine (cases 1-6 and 8-10) had been established in our institute [25][26][27][28] and the other was U-251MG (case 7). 29) The pathological diagnosis of the primary tumors from which the cell lines were established was anaplastic glioma (WHO grade III) in 8 cases and glioblastoma (WHO grade IV) in 2 cases.…”