TRANSFORMING POTENTIAL OF CELLULAR ONCOGENES

这些实验的目的是评估细胞的能力， 癌基因（c-onc）在体内转化细胞。 转化潜力 将检测两种小鼠c-onc基因c-fos和c-mos。 一些 含有这些c-onc基因的DNA构建体， 选择性标记基因、诱导型启动子和/或LTR增强子区 将被制造。 这些构建体将被转移到小鼠胚胎来源的 畸胎瘤细胞（EK细胞）的DNA转染。 克隆 来自单个转染细胞的细胞系将被表征为 确定插入的c-onc基因的数目，整合的数目， 位点和c-onc转录活性。 转染的EK细胞将被 引入到两个体内测试系统中以评估转化 c-fos和c-mos的电位。 在第一个系统中，转染的EK细胞 将被注射到小鼠胚泡中以产生嵌合小鼠。 的 这些小鼠中肿瘤的形成和c-onc转录活性将 进行评估。 在第二个系统中，转染的EK细胞或嵌合的EK细胞被转染。 胚胎（注射转染的EK细胞的胚泡）将被 移植到成年小鼠宿主的异位部位， 畸胎瘤将被表征。 这些具体目标 实验是为了确定是否：（1）增加的c-onc转录是 足以在小鼠中诱导肿瘤形成和/或改变肿瘤细胞的生长。 畸胎癌和畸胎瘤的发病率， 将胚胎或畸胎瘤细胞移植到成人的异位部位 宿主，或（2）\是否在c-onc基因的改变是必要的激活 其在体内的转化潜力。 此外，这些结果 实验将阐明一些因素的影响，包括 遗传背景、组织特异性和整合位点， c-onc基因的转化潜力。 的理解 这些细胞基因的转化潜力将直接影响 采用治疗中使用的策略，并最终， 预防人类癌症。 （十）

The purpose of these experiments is to assess the ability of cellular oncogenes (c-onc) to transform cells in vivo. The transforming potential of two mouse c-onc genes, c-fos and c-mos, will be examined. A number of DNA constructs containing these c-onc genes in combination with dominant selectable marker genes, inducible promoters, and/or LTR enhancer regions will be made. These constructs will be transferred to mouse embryo-derived teratocarcinoma cells (EK cells) using DNA transfection procedures. Clonal lines derived from single transfected cells will be characterized to determine the number of inserted c-onc genes, the number of integration sites, and c-onc transcriptional activity. Transfected EK cells will be introduced into two in vivo test systems to assess the transforming potential of c-fos and c-mos. In the first system, transfected EK cells will be injected into mouse blastocysts to produce chimeric mice. The formation of tumors and c-onc transcriptional activity in these mice will be assessed. In the second system, transfected EK cells or chimeric embryos (blastocysts injected with transfected EK cells) will be transplanted to ectopic sites in adult mouse hosts and the resulting teratoid tumors will be characterized. The specific aims of these experiments are to determine whether: (1)\increased c-onc transcription is sufficient to induce tumor formation in a mouse and/or to alter the incidence of teratocarcinomas and teratomas formed as a result of transplanting embryos or teratocarcinoma cells to ectopic sites in adult hosts, or (2)\whether alterations in a c-onc gene are necessary to activate its transforming potential in vivo. Additionally, the results of these experiments will elucidate the effects of a number of factors, including genetic background, tissue specificity, and integration site(s), on the transforming potential of c-onc genes. An understanding of the transforming potential of these cellular genes will directly influence the adoption of strategies used in the treatment and, ultimately, in the prevention of human cancer. (X)