在前期工作已证实HCV基因组5’UTR DNA序列具有启动子活性的基础上，分别构建5’UTR 不同结构域的DNA序列驱动虫荧光素酶基因表达的质粒pGL3-5’UTR，转染HepG2细胞以及用全长的5’UTR cDNA构建质粒分别转染HepG2、Hela、HEK293、L02细胞，用双荧光素酶检测系统检测虫荧光素酶的表达水平，逆转录聚合酶链反应检测虫荧光素酶基因mRNA水平，并与相应对照作比较。结果显示当四个结构域都具备时，荧光素酶相对活性为5.91±0.65，为SV40启动子的18.7%；失去结构域I以后，荧光素酶相对活性为9.52±0.32；失去结构域I和II以后，荧光素酶相对活性为2.64±0.25；失去结构域III和IV以后，荧光素酶相对活性为0.32±0.09；失去结构域IV以后，荧光素酶相对活性为2.72±0.45，逆转录聚合酶链反应结果与之相符；全长5’UTR cDNA在L02、hepG2、HEK293、Hela细胞中荧光素酶相对活性分别为0.75，0.49，0.23，0.14。 结果提示结构域III是HCV5’UTR DNA序列具备启动子活性的核心结构，结构域I对其5’UTR DNA序列的启动子活性具有抑制效应，而结构域II和IV可增强5’UTR DNA序列的启动子活性；HCV5’UTR cDNA的启动子功能无组织特异性，但在正常的肝细胞（L02）中表达最高。

Based on a previous study, a pGL3-5’UTR plasmid was constructed by substitution of the SV40 promoter with HCV 5’UTR cDNA. A set of deletion mutant plamids: pGL3-5’UTR1 comprising the full sequence of 5’UTR; pGL3-5’UTR2 containing domains II, III and IV; pGL3-5’UTR3 containing domains I, II and III; pGl3-5’UTR4 with domains III and IV; pGl3-5’UTR5 with domains I and II were constructed. HepG2 cells were transfected with the above plasmids. The plasmid carrying the full-length of 5’UTR was transfected into hepG2, Hela, HEK293 and Hela cells. The luciferase mRNA and the enzymatic activity were then detected. The relative luciferase activity associated with the pGL3-5’UTR1, pGL3-5’UTR2, pGL3-5’UTR3, pGL3-5’UTR4 and pGL3-5’UTR5 were 5.91±0.65, 9.52±0.32, 2.72±0.45, 2.64±0.25 and.32±0.09, respectively. The luciferase activity was evident in all four cell lines. The data suggested that the DNA sequence of stem-loop III was the core structure and the domain I, II and IV had a regulating effect. It also showed that cells originated from various tissues could provide efficient accessory factors for HCV 5’UTR sequence than strictly act as a promoter and that the original cells may be the most suitable.