Tagliaferri P, Yanagihara K, Ciardiello F, Talbot N, Flatow U, Benade L, Bassin R H
Laboratory of Tumor Immunology and Biology, National Cancer Institute, Bethesda, MD 20892.
Int J Cancer. 1987 Nov 15;40(5):653-8. doi: 10.1002/ijc.2910400514.
Both murine and human cell lines transformed by the v-Ki-ras gene have been shown to be much more sensitive to the toxic effects of the cardiac glycoside ouabain than their respective controls. This differential toxicity has previously been used in the isolation of flat revertant clones from populations of Kirsten murine sarcoma virus transformed NIH/3T3 cells. Here, we have undertaken a further characterization of this phenomenon in murine and human tumor cells. Two different techniques, a 51Cr-release assay and a quantitative Crystal violet elution assay, have been employed to compare the sensitivities to ouabain of normal and v-Ki-ras-transformed NIH/3T3 cells. In each assay, ras-transformed NIH/3T3 cell lines displayed an increased sensitivity to ouabain as compared to the parental NIH/3T3 cell line, both in dose-response and in time-course experiments. In a separate study, ouabain was also able to inhibit the growth in semi-solid medium of 2 v-Ki-ras-transformed NIH/3T3 cell lines (DT and K-NIH) in a dose-dependent fashion. The same concentrations of ouabain were effective in both the 51Cr-release and Crystal violet assays. To address the question of whether increased sensitivity to ouabain is a specific result of transformation with the ras oncogene or is a common event which accompanies transformation by other oncogenes, we have screened a variety of transformed NIH/3T3 derivatives. All of these lines displayed an increased sensitivity to ouabain when compared to the parental NIH/3T3 cell line.
已证实，被v-Ki-ras基因转化的小鼠和人类细胞系对强心苷哇巴因的毒性作用比各自的对照细胞系敏感得多。这种差异毒性先前已被用于从 Kirsten 小鼠肉瘤病毒转化的 NIH/3T3 细胞群体中分离扁平回复克隆。在此，我们对小鼠和人类肿瘤细胞中的这一现象进行了进一步的表征。采用了两种不同的技术，即51Cr释放试验和定量结晶紫洗脱试验，以比较正常和v-Ki-ras转化的 NIH/3T3 细胞对哇巴因的敏感性。在每个试验中，无论是剂量反应试验还是时间进程试验，与亲本 NIH/3T3 细胞系相比，ras 转化的 NIH/3T3 细胞系对哇巴因的敏感性都有所增加。在另一项研究中，哇巴因还能够以剂量依赖的方式抑制 2 种 v-Ki-ras 转化的 NIH/3T3 细胞系（DT 和 K-NIH）在半固体培养基中的生长。相同浓度的哇巴因在 51Cr 释放试验和结晶紫试验中均有效。为了解对哇巴因敏感性增加是 ras 癌基因转化的特定结果还是其他癌基因转化所伴随的常见事件这一问题，我们筛选了多种转化的 NIH/3T3 衍生物。与亲本 NIH/3T3 细胞系相比，所有这些细胞系对哇巴因的敏感性都有所增加。
