Katsuta H, Takaoka T
Jpn J Exp Med. 1979 Jun;49(3):187-98.
Liver tissue of a suckling rat was cultured. After 3 weeks of cultivation, the cultures consisting of epithelial cells were treated with 50 micrograms/ml or 100 micrograms/ml DEN for 7 days. 5 months after the treatment, the mode of chromosome number was found decreased from 42 to 40 in the 100 micrograms/ml DEN-treated group and shifted to triploid range after 21 months. The mode in the 50 micrograms/ml DEN-treated group maintained the diploid number until the 5th month but was found reduced to 40 in 21 months. On subcutaneous backtransplantation into young rats at the 22nd month, the treated cells produced tumors at the site inoculated in all the rats. Metastatic foci were also detected in lungs. These tumors were histologically diagnosed as hepatomas. Untreated control cells did not produce tumors. The differential effects of cytochalasine B on the cells with and without tumorigenicity were examined by the use of these cells and other cells, and it revealed that the capacity of multinucleated cell-formation by cytochalasin B fairly corresponds with the backtransplantability of the cells. Binucleated cell formation, not more than 2 nuclei, in the culture of normal cells was found by time-lapse cinemicrography to be not due to the non-capacity of multinucleation but to the destruction of multinucleated cells.
对一只乳鼠的肝脏组织进行培养。培养3周后，用50微克/毫升或100微克/毫升的二乙基亚硝胺（DEN）处理由上皮细胞组成的培养物7天。处理后5个月，在100微克/毫升DEN处理组中，染色体数目的众数从42降至40，21个月后转变为三倍体范围。50微克/毫升DEN处理组的众数在第5个月前保持二倍体数目，但在21个月时降至40。在第22个月将处理后的细胞皮下回植到幼鼠体内，处理后的细胞在所有接种部位的大鼠中均产生肿瘤。在肺中也检测到转移灶。这些肿瘤经组织学诊断为肝癌。未处理的对照细胞未产生肿瘤。利用这些细胞和其他细胞研究了细胞松弛素B对具有和不具有致瘤性的细胞的不同作用，结果表明细胞松弛素B形成多核细胞的能力与细胞的回植能力相当。通过延时电影显微镜观察发现，正常细胞培养中双核细胞形成（核数不超过2个）不是由于多核化能力不足，而是由于多核细胞的破坏。
