前言化学毒物是重要的致癌因子之一。不论它们是直接与DNA结合或是通过其他途径,其最终的过程都会使组织细胞过度分裂增殖,这是细胞恶变的重要环节。而促进细胞向恶性方向过度分裂增殖的内部因素是控制细胞转化的基因发生突变。无论是细胞内部的或是外界因素均可造成细胞遗传缺陷,从而改变细胞固有的遗传性状,也就是增加细胞突变率。对肿瘤细胞进行分子遗传学分析发现不仅细胞染色体脆性增加,而且基因组存在多种遗传缺陷,包括易位,点突变、基因扩增等。如果控制正常细胞分裂生长的抑制基因发生改变、丢失或失活,即可极大促进细胞恶变速率,提高细胞分 Introduction Chemical poisons are one of the important carcinogenic factors. Whether they are directly combined with DNA or through other pathways, the final process will make the tissue cells excessively proliferate, which is an important part of cell malignant transformation. The internal factor that promotes cell proliferation in the malignant direction is the gene mutation that controls the cell transformation. Both intracellular and external factors can cause genetic defects in cells, thereby altering the cell’s inherent genetic traits, which is to increase the cell mutation rate. The molecular genetic analysis of tumor cells revealed that not only the chromosome friability increased, but also there were multiple genetic defects in the genome, including translocations, point mutations, and gene amplification. If the inhibitory gene that controls normal cell division growth changes, loses or is inactivated, it can greatly promote the malignant transformation rate of cells and increase cell division.