Milo G E, Oldham J W, Zimmerman R, Hatch G G, Weisbrode S A
In Vitro. 1981 Aug;17(8):719-29. doi: 10.1007/BF02628409.
Several different classes of chemical carcinogens induced the transformation of human fibroblasts grown in vitro. Characteristics of the events that occur from time of treatment through the expression of neoplastic transformation are presented. The S-phase appeared to be the portion of the cell cycle most vulnerable to insult. Staging of the cells by blocking them in G1 before releasing them to proceed through scheduled DNA synthesis (S) was required to induce reproducible transformation. Compounds such as insulin were added to the cells upon release from the block to sensitize the cells to the carcinogen that was added during S. Growth of the transformed cells as distinct from nontransformed cells was promoted by growth in medium supplemented with 8X nonessential amino acids. Carcinogen-treated cells in the early stage of transformation exhibited abnormal colony morphology and were able to grow at 41 degrees C, in air atmosphere, and in medium supplemented with only 1% serum. In addition, the transformed cells were insensitive to KB cell lysate and exhibited density independent, as well as anchorage independent, growth (i.e., growth in 0.33% agar). Cells that grew in soft agar also produced undifferentiated mesenchymal tumors in preirradiated nude mice.
几种不同类型的化学致癌物可诱导体外培养的人成纤维细胞发生转化。本文介绍了从处理时到肿瘤转化表现过程中所发生事件的特征。S期似乎是细胞周期中最易受损伤的部分。需要通过在G1期阻断细胞，然后再使其进入预定的DNA合成（S）期来对细胞进行分期，以诱导可重复的转化。从阻断状态释放细胞时，向细胞中添加胰岛素等化合物，以使细胞对S期添加的致癌物敏感。在补充了8倍非必需氨基酸的培养基中生长可促进转化细胞与未转化细胞不同的生长。处于转化早期的致癌物处理细胞表现出异常的集落形态，并且能够在41摄氏度、空气环境以及仅添加1%血清的培养基中生长。此外，转化细胞对KB细胞裂解物不敏感，表现出密度依赖性和锚定非依赖性生长（即在0.33%琼脂中生长）。在软琼脂中生长的细胞在预先照射过的裸鼠中也会产生未分化的间充质肿瘤。
