大鼠肝卵圆细胞体外培养过程中癌基因的表达变化及其意义

目的研究大鼠肝卵圆细胞体外培养过程中癌基因的表达变化与细胞转化的关系。方法用化学致癌剂３′ＭｅＤＡＢ诱发ＳＤ大鼠肝卵圆细胞增生,采用Ｐｅｒｃｏｌ密度梯度离心法将肝卵圆细胞进行分离和体外长期培养。在培养过程中,通过ＲＮＡＤＮＡｓｌｏｔｂｌｏｔ杂交方法,动态观察Ｈａｒａｓ、Ｋｉｒａｓ和ｃｍｙｃ癌基因的表达变化。结果卵圆细胞在培养过程中倍增时间逐渐缩短,非整倍体染色体数目增加,在软琼脂中生长的克隆增多。ｃｍｙｃ、Ｋｉｒａｓ和Ｈａｒａｓ的表达在细胞培养和转化的不同阶段均表现同步关系,即同时升高或降低。结论癌基因的表达反复升高与细胞转化过程相关联,而且,卵圆细胞的转化有赖于多个癌基因激活

The characteristics and significance of oncogenes expression in oval cells cultivated in vitro

OBJECTIVE: To study the relationship between expression characteristics of oncogenes and transformation of the oval cells cultivated in vitro. METHODS: Liver oval cells of SD rats induced by feeding with chemical carcinogen 3'-Me-DAB for four weeks were isolated using Percoll density gradient centrifugation. The cells were continuously cultivated in vitro and the dynamic characteristics of Ha-ras, Ki-ras and c-myc genes expression in the oval cells were detected using RNA-DNA slot blot hybridization. RESULTS: During long term cultivation, the population doubling time of the cells became shorter and the percentage of aneuploidy chromosomes and colonies grown in soft agar increased. Ha-ras Ki-ras and c-myc were synchronically expressed in the oval cells from different passages. CONCLUSION: The activation and synergistic over-expression of Ha-ras Ki-ras and c-myc had an important role in the proliferation and transformation of oval cells in vitro.