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癌是基因病,这种看法已经被人们所广泛接受。但在癌症时,究竟是哪些基因发生了怎样变化至今尚未完全弄清。70年代后期,以 DNA 重组技术为中心的分子生物学有了长足的进展,使分析癌的基因变化成为可能。结果发现癌的基因变化至少有三类:①癌基因的改变;②癌抑制基因的改变;③病毒感染等外源性基因重组等。这些基因变化可因脏器不同而各异,而且既或是同一脏器也因组织型或癌的进展期不同而异。弄清癌的各种基因的变化无疑对于癌的基因诊断、预后判定和开发新疗法都是极其重要的。一、癌的基因改变1.癌基因癌基因变异可有点突变、扩增和重组等几种形式。通常基因存在于分别来自父亲和母亲的染色体上,每个细胞有二个拷贝。某个特定基因有时可从数个拷贝扩增达100个拷贝。多种癌均可看到癌基因的扩增,例如 N-myc、ras 基因组、C-erbB-2、K-Samhst-1等。扩增率亦不同,约为10～50%。
Cancer is a genetic disease. This view has been widely accepted by people. However, in the case of cancer, it has not yet been fully understood what genes have changed. In the late 1970s, the molecular biology centered on DNA recombination technology has made great progress, making it possible to analyze genetic changes in cancer. As a result, it has been found that there are at least three types of cancer gene changes: 1 alteration of oncogenes; 2 alteration of cancer suppressor genes; 3 reorganization of exogenous genes such as viral infections. These genetic changes can vary from organ to organ, and are either the same organ or different tissue type or cancer progression. Understanding the changes in various genes of cancer is undoubtedly extremely important for the diagnosis of cancer, the determination of prognosis, and the development of new therapies. First, cancer gene changes 1. Oncogene mutations can be a little mutation, amplification and reorganization in several forms. Genes are usually present on chromosomes from father and mother, respectively, with two copies of each cell. A particular gene can sometimes be amplified up to 100 copies from several copies. The oncogene amplification can be seen in many cancers, such as N-myc, ras genome, C-erbB-2, K-Samhst-1 and so on. The amplification rate is also different, about 10 to 50%.