Brand K G, Buoen L C, Brand I
Department of Microbiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA.
J Natl Cancer Inst. 1967 Oct;39(4):663-79.
Inbred CBA/H and CBA/H-T6 mice received implants of 15 X 22 mm plastic films. Plastic inserts and tissue capsules were cut in thirds at half monthly and monthly intervals. The first portion of the inserts and capsules was left in the original animal. The second portion was separated and individually transplanted into recipients that differed from the original animals with respect to the T6 marker chromosome. The third portion and all tumors which developed in original and recipient animals were examined by karyological, histological, and cultural methods. Film pieces caused tumors in recipient animals up to 9 months after transfer, capsule tissue only up to about 1 month after transfer. Tumors in original and corresponding recipient animals were identical in their chromosomal stemlines and pace of premalignant maturation. The karyotype of the stemline was never discovered among the film-attached cell population because there seemed to be no cell division. This points to the existence of a single, specific premalignant cell clone residing on the film surface in a dormant state of nondivision many months before tumor appearance. At the end, the (pre)malignant cells detached from the film, invaded the capsule tissue, and propagated to produce the tumor within about 4 weeks. The existence of a specific inhibition phenomenon during the premalignant phase is suggested.
近交系CBA/H和CBA/H-T6小鼠接受了15×22毫米塑料薄膜植入。塑料插入物和组织包膜分别在半月和每月间隔时切成三段。插入物和包膜的第一部分留在原动物体内。第二部分分离出来，分别移植到与原动物在T6标记染色体方面不同的受体动物体内。第三部分以及原动物和受体动物体内长出的所有肿瘤均采用核型分析、组织学和培养方法进行检查。薄膜碎片在转移后长达9个月的时间里能在受体动物体内引发肿瘤，而包膜组织仅在转移后约1个月的时间里引发肿瘤。原动物和相应受体动物体内的肿瘤在染色体主干系和癌前成熟速度方面是相同的。在附着于薄膜的细胞群体中从未发现主干系的核型，因为似乎没有细胞分裂。这表明在肿瘤出现前许多个月，在薄膜表面存在一个单一的、特定的癌前细胞克隆，处于不分裂的休眠状态。最后，（癌）前体细胞从薄膜上脱离，侵入包膜组织，并在约4周内增殖形成肿瘤。提示在癌前阶段存在一种特定的抑制现象。
