Tse T P, Morris H P, Taylor J M
Biochemistry. 1978 Jul 25;17(15):3121-8. doi: 10.1021/bi00608a028.
The level of albumin mRNA in the normal Buffalo rat liver and Morris hepatoma 7777 was compared by molecular hybridization with albumin complementary DNA (cDNA) and translational assays. Albumin mRNA was found to be 10% of the total rat liver poly(A)-containing RNA population but reduced approximately fourfold in the case of Morris hepatoma 7777. An equivalent decrease of albumin mRNA activity in the hepatoma was detected by translation in a mRNA-dependent cell-free protein-synthesizing system. A proportional increase in total hepatoma poly(A)-containing RNA was not observed, indicating that there was a true fourfold reduction of albumin synthesis in the hepatoma. DNA excess hybridization with albumin cDNA did not reveal any apparent change in albumin gene frequency in the hepatoma compared to normal liver. Complementary DNA copies of total liver and hepatoma poly(A)-containing RNA were synthesized and employed in homologous and heterologous hybridization reactions. Analyses of these reactions showed a high degree of homology between the poly(A)-containing RNA of the liver and hepatoma, with some difference in the relative sequence abundancy. However, qualitative differences were detected in hepatoma 7777 consistent with the concept of alterations in the control of gene expression upon neoplastic transformation.
通过与白蛋白互补DNA（cDNA）进行分子杂交及翻译分析，比较了正常水牛大鼠肝脏和莫里斯肝癌7777中白蛋白mRNA的水平。发现白蛋白mRNA占大鼠肝脏总含poly(A)RNA群体的10%，但在莫里斯肝癌7777中约减少了四倍。在依赖mRNA的无细胞蛋白质合成系统中进行翻译时，检测到肝癌中白蛋白mRNA活性有同等程度的下降。未观察到肝癌总含poly(A)RNA成比例增加，表明肝癌中白蛋白合成确实减少了四倍。与白蛋白cDNA进行DNA过量杂交未显示肝癌中白蛋白基因频率与正常肝脏相比有任何明显变化。合成了肝脏和肝癌总含poly(A)RNA的互补DNA拷贝，并用于同源和异源杂交反应。对这些反应的分析表明，肝脏和肝癌的含poly(A)RNA之间具有高度同源性，只是相对序列丰度存在一些差异。然而，在肝癌7777中检测到了定性差异，这与肿瘤转化后基因表达调控改变的概念相符。
