CHARACTERIZATION AND SUBCLONING OF A NEW HUMAN ONCOGENE

先前从新人的粘粒克隆中获得的亚基因组克隆 癌基因，命名为DBL，用于弥漫性B细胞淋巴瘤，已被用于 为了检测这一新分离的癌基因在新鲜组织中的表达 人类肿瘤和肿瘤细胞系。在这次筛选中，一个cdna克隆 (代表DBL消息的不完整拷贝) 由NIH/3T3细胞构建的DBL转基因RNA文库 克隆，也曾被使用过。在筛选的大约100种RNA制剂中， Northern杂交检测到阳性杂交信号 新鲜肿瘤或细胞系的10种不同制备方法。这个 阳性样本包括明显起源于中胚层的细胞系，如 纤维肉瘤、横纹肌肉瘤和肌肉瘤。细胞系与新鲜肿瘤 来自尤文肉瘤(一种起源于细胞的肿瘤)的样本 仍然存在争议)一直被发现是积极的。进一步 对癌基因的鉴定包括对cdna的筛选。 从转染的NIH/3T3细胞中获得文库，以分离5‘端 缺少DBL基因的一部分。来自这个的cDNA片断 已经获得了该基因的区域，并最终将导致 全长cDNA克隆的构建。

Subgenomic clones previously obtained from a cosmid clone of a new human oncogene, designated dbl for diffuse B cell lymphoma, have been utilized in order to detect the expression of this newly isolated oncogene in fresh human tumors and tumor cell lines. For this screening, a cDNA clone (representing an incomplete copy of the dbl message) obtained from a cDNA library constructed from NIH/3T3 cells in RNAs transfected with the dbl clone, has also been used. Among about 100 RNA preparations screened, positive hybridization signals have been detected by northern blotting with 10 different preparations of either fresh tumors or cell lines. The positive samples included cell lines of clear mesodermal origin, such as fibrosarcomas, rhabdo-and leio-myosarcomas. Cell lines and fresh tumor samples derived from Ewing's sarcoma (a type of tumor whose cell of origin is still controversial) were consistently found to be positive. Further characterization of the oncogene has included the screening of the cDNA library obtained from transfected NIH/3T3 cells in order to isolate the 5' missing portions of the dbl gene. Fragments of cDNA coming from this region of the gene have been obtained and will eventually lead to the construction of a full length cDNA clone.