Sakai Y, Wajjwalku W, Takahashi M, Masuda A, Utsumi K R, Matsuyama M
Department of Pathology, Nagoya University School of Medicine, Japan.
Nagoya J Med Sci. 1993 Mar;55(1-4):125-30.
To analyze the processes of the development of thymoma and malignant thymoma from normal thymic epithelial cells, we have examined the expression of 15 proto-oncogenes and tumor suppressor genes in seven in vitro epithelial cell lines established from a normal thymus (TuD1-1, TuD1-3, and TuD1-5), thymoma (TaD1-3 and TaD1-8), and malignant thymoma (MTHC-1 and MTHC-3) of rats. Northern blot analysis indicated that most of these genes examined were transcribed at similar levels. However, higher levels of transcription of epidermal growth factor receptor (EGFR) were observed in TuD1-1, TuD1-3, TuD1-5, TaD1-3, and TaD1-8 cells than in MTHC-1 and MTHC-3 cells. Conversely, four of the former five cell lines showed no TGF-beta transcription while the latter two cell lines had high levels of its expression. In addition, c-fos proto-oncogene was highly expressed in TuD1-5 cells, which showed the fastest growth rate among the seven cell lines. These results denote that some molecular changes in the regulation of gene expression occurred in the processes of malignant transformation of thymic epithelial cells.
为了分析正常胸腺上皮细胞发展为胸腺瘤和恶性胸腺瘤的过程，我们检测了从大鼠的正常胸腺（TuD1-1、TuD1-3和TuD1-5）、胸腺瘤（TaD1-3和TaD1-8）以及恶性胸腺瘤（MTHC-1和MTHC-3）建立的7种体外上皮细胞系中15种原癌基因和抑癌基因的表达。Northern印迹分析表明，所检测的这些基因大多数转录水平相似。然而，在TuD1-1、TuD1-3、TuD1-5、TaD1-3和TaD1-8细胞中观察到表皮生长因子受体（EGFR）的转录水平高于MTHC-1和MTHC-3细胞。相反，前5种细胞系中有4种未检测到TGF-β转录，而后2种细胞系则有高水平的表达。此外，c-fos原癌基因在TuD1-5细胞中高表达，该细胞系在7种细胞系中生长速度最快。这些结果表明，胸腺上皮细胞恶性转化过程中发生了基因表达调控的一些分子变化。
