到现在为止,人们对癌变的基本分子机理还了解得很少。化学致癌物或其代谢物可同DNA起反应,并可引起突变。它们还可同RNA、蛋白质及其他细胞组分起反应。DNA病毒的核酸可整合到细胞的基因组中,并使细胞转化,但发生了逆转(Reversion)的细胞虽然带着整合进去的病毒DNA,却往往很少表现出转化细胞的任何特性。多数癌细胞在继续生长时,其核型变成非整倍体,但也有少数癌细胞分化或逆转为正常的、非恶性的表型(Phenotype)。由于存在着这些互相矛盾的事实,所以对癌瘤究竟是由于基因型(Geno Until now, little is known about the basic molecular mechanisms of carcinogenesis. Chemical carcinogens or their metabolites can react with DNA and cause mutations. They also react with RNA, proteins and other cellular components. The nucleic acid of the DNA virus can be integrated into the genome of the cell and cause the cell to transform, but the cells that have undergone a reversion, although carrying the integrated viral DNA, rarely show any characteristics of the transformed cell. While most cancer cells continue to grow, their karyotype becomes aneuploid, but a few cancer cells differentiate or revert to a normal, non-malignant phenotype (Phenotype). Because of these contradictory facts, it is due to the genotype (Geno)