Patek P Q, Lin Y, Collins J L, Cohn M
J Immunol. 1986 Jan;136(2):741-5.
Experiments were designed to test the hypothesis that transformed cells that are NC sensitive must escape NC activity if they are to grow as tumors in normal individuals. NC-resistant variants were selected either in vivo or in vitro from NC-sensitive cell lines that grow as tumors in immunodeficient mice but not in syngeneic normal mice. The tumorigenicity of cloned NC-resistant variants was compared with the parental cell lines and to cell lines that went through the selection procedure, but after cloning remained NC sensitive. Cloned NC-resistant cell lines derived from tumors that developed in x-irradiated nude mice after the injection of an NC-sensitive cell line are tumorigenic in normal mice, whereas cloned NC-sensitive cell lines derived from the same tumors are unable to grow as tumors in normal mice. Similarly, six of seven NC-resistant cloned cell lines independently isolated after in vitro selection for NC-resistance are tumorigenic in normal mice, whereas cloned NC-sensitive cell lines isolated from the same in vitro selected populations are not tumorigenic in normal mice. Thus, either the in vivo or in vitro selection of NC-resistant cells selects for cells tumorigenic in normal mice; these findings, along with our previous observations that selection for cells tumorigenic in normal mice selects for NC resistance, provide compelling evidence that escape from NC activity is required before some transformed cells can grow as tumors in normal mice.
对自然杀伤（NK）敏感的转化细胞若要在正常个体中形成肿瘤，必须逃避NK活性。NK抗性变体是从在免疫缺陷小鼠而非同基因正常小鼠中形成肿瘤的NK敏感细胞系中，在体内或体外筛选出来的。将克隆的NK抗性变体的致瘤性与亲代细胞系以及经过筛选程序但克隆后仍对NK敏感的细胞系进行比较。注射NK敏感细胞系后在经X射线照射的裸鼠中形成肿瘤的克隆NK抗性细胞系在正常小鼠中具有致瘤性，而源自同一肿瘤的克隆NK敏感细胞系在正常小鼠中无法形成肿瘤。同样，在体外筛选出NK抗性后独立分离的七个克隆NK抗性细胞系中有六个在正常小鼠中具有致瘤性，而从相同体外筛选群体中分离的克隆NK敏感细胞系在正常小鼠中不具有致瘤性。因此，无论是在体内还是体外筛选NK抗性细胞，筛选出的都是在正常小鼠中具有致瘤性的细胞；这些发现，连同我们之前的观察结果，即在正常小鼠中筛选具有致瘤性的细胞会筛选出NK抗性，提供了令人信服的证据，表明在一些转化细胞能够在正常小鼠中形成肿瘤之前，必须逃避NK活性。
