Characterization of a new human glioblastoma cell line that expresses mutant p53 and lacks activation of the PDGF pathway.
Characterization of a new human glioblastoma cell line that expresses mutant p53 and lacks activation of the PDGF pathway.
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表达突变型 p53 且缺乏 PDGF 途径激活的新型人胶质母细胞瘤细胞系的表征。
DOI：
10.1007/bf02639435
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Lin,H
中科院分区：
文献类型：
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作者：
Gjerset,RA;Fakhrai,H;Shawler,DL;Turla,S;Dorigo,O;Grover-Bardwick,A;Mercola,D;Wen,SF;Collins,H;Lin,H
我们从一名患有多形性胶质母细胞瘤的成年女性患者的活检样本中建立并鉴定了一种新的胶质母细胞瘤细胞系，称为 GT9。该品系现已传代60多次，并在冻存后培养成功。一组单克隆抗体的免疫荧光分析显示神经胶质原纤维酸性蛋白和波形蛋白呈阳性，而神经丝、半乳脑苷脂和纤连蛋白（神经胶质细胞的典型模式）呈阴性。基于四倍体，GT9 细胞的复合核型包括 10 号染色体缺失、7 号染色体增加以及双微小染色体的存在，这是胶质母细胞瘤中最常见的三种核型异常。 p53 cDNA 的序列分析显示密码子 249（在黄曲霉毒素相关肝细胞癌中常见突变）和密码子 250 处存在纯合双突变。此外，野生型 p53 完全缺失。然而，与之前描述的大多数人类胶质母细胞瘤不同，GT9细胞中血小板衍生生长因子-B (PDGF-B)（一种有效的促有丝分裂自分泌因子）的表达较低。 PDGF 途径下游介质 c-Jun 和 Jun-B 的表达和磷酸化也较低。因此，PDGF 通路的失调似乎并不参与 GT9 胶质母细胞瘤的发病机制。相反，细胞生长的负调节因子 Jun-D 的含量也较低。此外，磷酸化 Egr-1（最近报道的 PDGF-B/v-sis 转化细胞的抑制因子）也较低，表明 PDGF 途径缺乏激活并不是由这些抑制机制造成的。人胶质母细胞瘤中弱或无活性的PDGF-B自分泌机制与纯合改变的p53配对的情况表明p53抑制功能的丧失可能是这些细胞转化表型的主要贡献。
We have established and characterized a new glioblastoma cell line, termed GT9, from a biopsy sample of a female adult patient with glioblastoma multiforme. The line has now undergone over 60 passages and has been successfully cultured after cryopreservation. Immunofluorescence analyses with a panel of monoclonal antibodies were positive for glial fibrillary acidic protein and vimentin, and negative for neurofilament, galactocerebroside, and fibronectin, a pattern typical of glial cells. Based on a tetraploid, the composite karyotype of GT9 cells included the loss of chromosome 10, gain of chromosome 7, and the presence of double minute chromosomes, three of the most common karyotypic abnormalities in glioblastoma. Sequence analysis of p53 cDNA revealed a homozygous double mutation at codon 249 (commonly mutated in aflatoxin-associated hepatocellular carcinoma) and codon 250. Moreover, there was a complete absence of wild-type p53. However, unlike the majority of human glioblastomas previously described, the expression of platelet-derived growth factor-B (PDGF-B), a potent mitogenic autocrine factor, was low in GT9 cells. The expression and phosphorylation of c-Jun and Jun-B, downstream mediators of the PDGF pathway, were also low. Thus, deregulation of the PDGF pathway does not appear to be involved in the pathogenesis of the GT9 glioblastoma. Conversely, Jun-D, a negative regulator of cell growth, was also low. In addition, Phosphorylated Egr-1, a recently reported suppressor of PDGF-B/v-sis-transformed cells, was also low, suggesting that the lack of activation of the PDGF pathway was not due to these suppressive mechanisms. The circumstance of a weak or inactive PDGF-B autocrine mechanism in human glioblastoma paired with a homozygously altered p53 suggests that the loss of suppressor function of p53 may be a major contribution to the transformed phenotype of these cells.