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转化生长因子β(TGF-β)/SMADS信号转导通路在肿瘤发生机制中发挥重要作用。近年来,许多研究表明了TGF-β超家族的配体、受体、SMAD蛋白、上游和下游调节因子与多种信号通路间的相互对话在不同肿瘤中的作用机制。Smad4基因是TGF-β信号转导系统的重要中间环节,其失活在人类肿瘤中占很高比例,可导致多种肿瘤的发生、发展。目前认为,Smad4基因的蛋白失活主要与该基因的缺失、突变和甲基化有关。突变包括无义突变、错义突变和移码突变等;缺失包括单等位基因杂合性缺失和双等位基因纯合性缺失。
Transforming growth factor β (TGF-β) / SMADS signal transduction pathway plays an important role in tumorigenesis. In recent years, many studies have shown that the mechanism of interaction between ligand, receptor, SMAD protein, upstream and downstream regulatory factors of TGF-β superfamily and various signaling pathways in different tumors. Smad4 is an important intermediate part of TGF-β signal transduction system. The inactivation of Smad4 in human tumors accounts for a high proportion, which can lead to the occurrence and development of many tumors. At present, the protein inactivation of Smad4 is mainly related to the deletion, mutation and methylation of the gene. Mutations include nonsense mutations, missense mutations and frameshift mutations; deletions include loss of heterozygosity for single alleles and loss of homozygosity for the two alleles.