大鼠肝癌变过程中细胞癌基因的表达

Expression of Cellular Oncogenes during Hepatocarcinogenesis in Rats

利用RNA-DNA杂交技术观察到:(1)在二乙基亚硝胺(DENA)诱发大鼠肝癌过程中,含有增生结节肝和肝细胞癌肝中c-Ha-ras、c-Ki-ras、N-ras和c-fos癌基因的表达都较正常肝高,而c-myc的表达无明显改变。(2)在两种不同诱发肝癌起始/促癌模型的起始阶段,c-myc的表达显著增高。在2-乙酰氨基芴作用下,N-ras表达的增高非常显著。c-myc和N-ras的表达似有协同作用。在促癌阶段,c-myc和N-ras的表达接近正常。(3)在起始和促癌过程中,c-fos的表达都显著降低,c-Ha-ras和c-Ki-ras表达变化不显著。对这些结果的意义作了初步讨论。

With RNA-DNA hybridization techniques, the mRNA expression of c-Ha-ras, c-Ki-ras, ,N7ras, and c-fos oncogenes in rat liver with neoplastic nodules or hepatocellular carcinoma induced by DENA was found to be higher than that in normal liver. No significant difference of c-myc expression was observed between normal liver and liver with neoplastic nodules or hepatocellular carcinoma. In the initiation stage of hepatocarcinogenesis in DENA+AAF+PH+PB and AAF+PH+PB model systems, the expression of c-myc increased markedly, and that of N-ras was remarkably stimulated under the action of AAF. It appears that a cooperative action between the c-myc and N-ras oncogenes was involved in the initiation of hepatocarcinogenesis. In the promotion stage, the expression of c-myc and N-ras returned to a normal level. The expression of c-fos decreased progressively in both the initiation and promotion stages, while that of c-Ha-ras and c-Ki-ras was not much changed. The significance of these results is briefly discussed.