肝细胞癌(Hepatocellular Carcinoma,HCC)是我国最常见的恶性肿瘤之一,多种致病因素与HCC发生相关,其中HBV(Hepatitis B Virus)的长期感染和AWB_1(Aflatoxin B_1)摄入量的增加是导致HCC的两大重要病因。HCC发病过程中涉及包括癌基因激活和抑制基因失活等多重遗传学改变,其中c—myc、TGFα做为癌基因在肝细胞中持续表达,以及抑癌基因p53因突变而失活在HCC中具有重要意义。有关AFB_1与HCC的相关性已经动物实验证实,但尚不清楚AFB_1在人类HCC中的致病机制。分子流行病学资料提示,AFB_1在HBV长期感染的背景上,可诱发人肝细胞中抑癌基因p53热点突变,这为AFB_1致HCC癌变机制研究提供了一个新的线索。目前人们对p53基因热点突变性质尚不明确,但推测它与细胞获得生长优势(growth advantage)有关。本课题首先通过分子流行病学研究进一步证实AFB_1与p53热点突变的相关性,进而以新生大鼠肝上皮细胞做为体外转化模型,探索AFB_1在特定的遗传学背景上使正常肝细胞永生化的可能性。在第一部分研究中,我们随机选择了AFB_1暴露量...
【英文摘要】
Hepatocellular carcinoma (HCC) is one of the most common cancers in the world, especially in China. Persistent HBV infection and increased exposure to dietary aflatoxin B1 (AFB_1) are two major causative factors that are related to HCC occurrence in area of prevalence. Many genetic abnormalities including activated oncogenes, such as the persistently expressed c—myc and TGFα, as well as inactivated tumor suppresser genes, such as p53, are implicated in the occurrence of HCC. Although AFB_1 involvement in HC...