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目前已知,与肝癌发病有关的癌基因有 ras基因的突变、c-myc mRNA 的过量表达或 DNA重排和基因放大等。其中 ras 基因有两个活化突变点:一是第12号密码子的第2个核苷酸,由原癌基因的 GGT 变成 CGT,由此获得转化活性;另一为第61号密码子。人类及其它哺乳动物有3种 ras 基因,即 Ha-ras、Ki-ras 和 N-ras,其编码的蛋白质 p21蛋白能通过和 GTP 或 GDP的结合来调节细胞的生长与分化,一旦 ras 基因突变导致 p21结构改变和功能异常,即有可能变、c-myc mRNA 的过量表达或 DNA 重排和基因放大等。其中 ras 基因有两个活化突变点:一
At present, it is known that oncogenes associated with the onset of hepatocarcinogenesis include ras gene mutation, c-myc mRNA overexpression, DNA rearrangement, and gene amplification. Among them, the ras gene has two activation mutation points: one is the second nucleotide of the 12th codon, which is changed from the GGT of the proto-oncogene to CGT, thereby obtaining the transforming activity; the other is the 61st codon. Humans and other mammals have three ras genes, namely Ha-ras, Ki-ras, and N-ras, whose encoded protein, p21, regulates cell growth and differentiation by binding to GTP or GDP once the ras gene has been mutated. Lead to p21 structural changes and abnormal function, that is, may change, c-myc mRNA overexpression or DNA rearrangement and gene amplification. The ras gene has two activation mutation points: