乙型肝炎病毒x蛋白促进裸鼠人肝癌模型的VEGF表达

HBx facilitates VEGF expression in transplanted human hepatoma tissue of the nude mouse

目的探讨乙型肝炎病毒x蛋白(HBx)促进肝癌细胞增殖的作用机制。方法将编码HBx基因全长的表达质粒pHA-HBx转染肝癌HepG2细胞,用G418筛选阳性克隆;采用逆转录聚合酶链反应(RT-PCR)鉴定HBx基因在HepG2细胞基因组的整合;分别用转染HBx基因前后的细胞建立肝癌裸鼠模型,观察两组裸鼠肿瘤组织生长增殖状况;采用免疫组织化学染色方法检测两组裸鼠肿瘤组织中VEGF的表达。结果 HBx基因成功整合入肝癌HepG2细胞基因组;转染HRx基因前后的两组HepG2细胞在裸鼠体内的接种成瘤率均为100％;转染HBx基因的肿瘤生长速度较未转染组明显加快;接种8周后,转染组肿瘤体积(2．86±0．34)cm3,未转染组为(2．48±0．22)cm3,两组间差异有统计学意义(t=1．905,P<0．05);转染组肿瘤组织中VEGF的表达较对照组明显增强(x2= 7．66,P<0．01)。结论 HBx可促进裸鼠肝癌组织VEGF表达,增加肝癌细胞的增殖活性,加速肿瘤组织生长。

Objective To investigate the mechanism by which HBx facilitates the proliferation of hepatoma cells. Methods The expression of plasmid pHA-HBx encoding full length of HBx was transfected into HepG2 cell lines and the transformed cells were identified by RT-PCR. The nude mouse model of transplanted human hepatoma HBx-transfected HepG2 cells was established. The expression of VEGF both in HepG2 cell-formed tumors and HBx-transfected cell-formed tumors in nude mice was examined immunohistochemically. Results RT-PCR showed that HBx gene was integrated into the genome DNA of HepG2 cells and amplified; The rate of tumor formation in nude mice both of HepG2 cells and HBx- transfected HepG2 cells was 100% ; The growth speed of HBx-transfected tumors was much faster than that in control group; The average volume of HBx-transfected tumors and non-transfected tumors was 2. 86 ± 0. 34 cm^3 and 2.48 ±0. 22 cm^3 respectively after 8 weeks（ t = 1. 905 ,P 〈0. 05）. The expression of VEGF in HBx- transfected tumor cells was much higher than that in control group （ x^2 = 7. 66, P 〈 0. 01 ）. Conclusion HBx up-regulates the expression of VEGF in hepatoma cells, which in turn increases the proliferation activity of the hepatoma cells.