Suggestive evidence for functionally distinct, tumor-suppressor genes on chromosomes 1 and 11 for a human fibrosarcoma cell line, HT1080.
Suggestive evidence for functionally distinct, tumor-suppressor genes on chromosomes 1 and 11 for a human fibrosarcoma cell line, HT1080.
复制标题
人类纤维肉瘤细胞系 HT1080 的 1 号和 11 号染色体上存在功能独特的肿瘤抑制基因的提示性证据。
作者：
H. Kugoh;H. Hashiba;M. Shimizu;M. Oshimura
鉴定携带推定肿瘤抑制基因的染色体的一种方法是将特定染色体引入感兴趣的肿瘤细胞。我们检测了来自正常成纤维细胞的人类染色体在裸鼠体内抑制或调节致瘤性的能力，以及HT1080（一种人类纤维肉瘤细胞系）的体外特性。我们首先分离出含有与pSV2neo质粒DNA整合的单个人类染色体（1、2、7、11或12）的小鼠A9细胞。将这些A9细胞的微细胞与HT1080细胞融合后，分离出抗G418的克隆并进行核型分析。引入1号染色体的4个微细胞杂种中有3个是非致瘤性的（#1-7、-8和-13），而亲本HT1080细胞具有高度致瘤性。另一种微细胞杂交克隆（#1-1）形成肿瘤，其细胞失去了1号染色体的一个拷贝。从#1-1细胞中分离出两个克隆；其中一个含有1号染色体的额外拷贝，另一个没有。前者无致瘤性，后者致瘤性。11号染色体的引入也抑制了HT1080细胞的致瘤性，而引入其他染色体，即2、7、12，对这些细胞的致瘤性影响很小或没有影响。通过引入2、7、12号染色体的微细胞杂交形成的肿瘤细胞仍然含有引入的染色体。有趣的是，只有引入1号染色体的微细胞杂交种在细胞形态和体外转化特性方面发生了改变，即在含有10%小牛血清的培养基中细胞生长和饱和密度以及在软琼脂中细胞生长。因此，这些结果表明HT1080细胞在1号和11号染色体上存在假定的肿瘤抑制基因，并进一步表明这些染色体上的基因控制着不同的肿瘤表型。
One approach for identifying chromosomes which carry putative tumor-suppressor genes is the introduction of specific chromosomes into the tumor cells of interest. We examined the ability of human chromosomes derived from normal fibroblasts to suppress or modulate tumorigenicity in nude mice and the in vitro properties of HT1080, a human fibrosarcoma cell line. We first isolated mouse A9 cells containing a single human chromosome (1, 2, 7, 11, or 12) integrated with pSV2neo plasmid DNA. Following fusion of microcells from these A9 cells with the HT1080 cells, clones that were resistant to G418 were isolated and karyotypically analysed. Three of 4 microcell-hybrids with an introduced chromosome 1 were non-tumorigenic (#1-7, -8 and -13), whereas the parental HT1080 cells were highly tumorigenic. The other microcell-hybrid clone (#1-1) formed tumors, the cells of which had lost one copy of chromosome 1. Two clones from the #1-1 cells were isolated; one contained an extra copy of chromosome 1, and the other one did not. The former was non-tumorigenic and the latter was tumorigenic. The introduction of chromosome 11 also suppressed the tumorigenicity of HT1080 cells, while the introduction of other chromosomes, i.e., 2, 7, or 12, had minimal or no effect on the tumorigenicity of these cells. Cells from tumors formed by microcell-hybrids with the introduction of chromosome 2, 7, or 12 still contained the introduced chromosome. Interestingly, only the microcell-hybrids with an introduced chromosome 1 had an alteration in cellular morphology and modulation of in vitro transformed properties, i.e., cell-growth and saturation density in a medium containing 10% calf serum and cell-growth in soft-agar. Thus, the results indicate the presence of putative tumor-suppressor genes for HT1080 cells on chromosomes 1 and 11, and further suggest that the genes on these chromosomes control different neoplastic phenotypes.