目的  构建人白细胞介素24（human interleukin-24，hIL-24）真核表达载体，并在HepG2细胞中稳定表达，为进一步研究其抗肿瘤作用奠定基础。方法    采用逆转录聚合酶链反应(RT-PCR)，从植物血凝素活化的人外周血单个核细胞中克隆得到hIL-24基因目的片段。应用DNA重组技术将IL-24 PCR产物双酶切后定向克隆至真核表达载体pcDNA3.1(+)，转化大肠杆菌DH5α获得重组载体，进行PCR、酶切及测序鉴定。应用脂质体将鉴定正确的重组质粒转染至HepG2细胞，用G418筛选稳定转染细胞株。采用RT-PCR检测稳定转染细胞HepG2中IL-24 mRNA的表达。结果   通过RT-PCR获得与预期大小一致约600 bp的IL-24基因片段；重组载体pcDNA3.1（+）- IL-24经PCR、双酶切及测序证实，IL-24 cDNA片段已正确插入真核表达载体中；在稳定转染的HepG2细胞株中可见到IL-24 mRNA表达。结论  成功构建了hIL-24真核表达载体pcDNA3.1(+)-IL-24，并获得了稳定转染该重组质粒的HepG2细胞株。 

Objective   To construct a eukaryotic expression vector of human interleukin-24 (hIL-24）and to observe its expression in HepG2 cells.  Methods   The hIL-24 gene was cloned from phytohemagglutinin-treated human peripheral blood mononuclear cells with RT-PCR. The eukaryotic expression vector pcDNA3.1(+)-IL-24 was constructed by subcloning IL-24 cDNA into the eukaryotic expressing vector pcDNA3.1(+) with DNA recombination technique and was identified by PCR, restriction enzyme digestion and DNA sequencing. The pcDNA3.1(+)-IL-24 was stably transfected into HepG2 cells by liposome transfection with using G418 to screen positive transformants. RT-PCR was performed to determine hIL-24 mRNA expression in HepG2 cells.  Results  The target gene with expected molecular mass was obtained with RT-PCR. The results of PCR, restriction enzyme digestion and DNA sequencing showed that the IL-24 gene had cloned into the eukaryotic vector pcDNA3.1(+) correctly. The mRNA of IL-24 was detected in the stably transfected HepG2 cells.  Conclusions  The recombinant eukaryotic expression vector pcDNA3.1(+)-IL-24 is constructed successfully and the HepG2
cell strains stably transfected with the recombinant plasmid are obtained.