人肝癌细胞p53基因的表达及其对细小病毒H-1的敏感性

p53 GENE EXPRESSION OF HUMAN HEPATOMA CELL LINES AND THEIR SENSITIVITIES TO PARVOVIRUS H-1

本文利用单链构象多态性分析,17号染色体短臂等位基因杂合性分析,Northern印迹,免疫沉淀,p53基因第7外显子酶切等技术检测了两个中国人肝癌细胞系SMMC-7721,YY-8103和一个自发转化的人肝细胞系L-02的p53基因结构与表达。实验表明,这三个细胞系中没有出现17号染色体短臂等位基因杂合性缺失,第4—9外显子也没发生突变,但其mRNA和蛋白表达水平很低。利用MTT比色分析法研究了这三个细胞系和其他已知p53基因背景的八个人肝癌细胞系(QGY-7703、PLC/PRF/5、Huh-7、Hep3B、FOCUS、Tong/ HCC、SK-Hep-1、HepG2)对自主性细小病毒H-1的敏感性。除HepG2细胞外,其他十个细胞系p53基因的结构和/或表达都不正常。经H-1感染(moi=20)后,其敏感性均高于HepG2细胞。本研究初步表明了p53基因结构或表达的不正常可能导致人肝癌或转化细胞对H-1的敏感性的提高。

DNA structure and expression of p53 gene in human hepatoma cell lines SMMC-7721, YY-8103 and a spontaneously transformed liver cell line L-02 were analysed using the following methods: analysis of allelic losses on chromosome 17p, PCR/SSCP, Northern blot and im-munoprecipitation. There was no point mutation found in the exons 4-9 of the p53 gene, and a low level of expression of p53 gene was detected in the three cell lines. These observations were in agreement to the reported results of the relevant experiment using the human hepatoma cell line QGY-7703. Sensitivities of these cell lines and other eight human hepatoma cell lines (QGY-7703, PLC/PRF/5, Tong/HCC, Huh-7, FOCUS, HepSB, SK-Hep-1, HepG2) with known p53 backgrounds to parvovirus H-l was assayed using MTT method. Abnormality in the structure and/ or function was observed in all of the cell lines examined except HepG2. The cell line HepG2 with normal structure and function of the p53 gene was found to be the least sensitive to H-l in comparison to all the cell lines which have defeated structure and/or function of the p53 gene. The present study serves as a preliminary evidence that enhancement of the sensitivity of human hepatoma cell lines to H-l is correlated to the abnormality of the structure and/or function of the p53 gene.