小鼠T细胞淋巴瘤在同基因鼠内传代的遗传学分析

Genetic Analysis of Mouse T-cell Lymphomas after Longterm Passage in Syngeneic Mice

作者研究了甲基亚硝基脲(methylnitrosourea,MNU)诱发RF/J系小鼠T细胞淋巴瘤及肿瘤细胞在同基因小鼠体内连续传代后的染色体变化。胸腺肿瘤细胞及其传代培养细胞染色体异常,皆发生在15、14、X、1、5、6、3号染色体,说明这些染色体含有促进肿瘤多步发生过程的基因即癌基因及抑癌基因。MNU不仅具有组织特异性而且累及特异染色体,结果也说明相同组织病理类型的肿瘤可产生于不同的特定位点的基因变化。

Since nonrandom chromosome changes in neoplastic cells have been proven to be good indicators of the site of gene alterations related to transformation,the authors examined the chromosomes of T - cell lymphomas induced in RF/J strain mice with methylnitrosourea (MNU) after long-term passage in syngeneic mice. All treated mice developed thymic lymphomas within 10 weeks after the injection. Chromosome of the thymus cells were examined at intervals before and during lymphoma development,as well as after they were passaged in syngeneic mice for periods up to 424 days. In preparations made directly from the thymus cells nonrandom numerical and structural alterations were found that involved the X,3,15,4,8,12,14 and 17 (Chromosomes showing alterations are listed in decreasing order of the frequency of their occurrence). In tumor cells passaged in syngeneic mice most of the above chromosomes were involved but the order was 15,14,X,1,5,6,3,11 and 12. The X,15,14,3 and 12 were aberrant in both direct preparations and in those from passaged cells,suggesting that these chromosomes carry genes (oncogenes or tumor suppressor genes) which,when altered,are particularly important in the multistep process of neoplastic transformation. MNU thus appears not only to be tissue specific but also to affect fairly specific chromosomes.