Lee Suyeon, Kim Kyunghwa, Kim Hyun Ah, Kim Sung Wan, Lee Minhyung
Department of Bioengineering, College of Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul, South Korea.
J Drug Target. 2008 Jan;16(1):43-50. doi: 10.1080/10611860701699693.
Therapeutic angiogenesis with gene encoding vascular endothelial growth factor (VEGF) is a potential treatment for ischemic diseases. However, VEGF expression should be tightly regulated to avoid side effects such as tumor growth. Previously, our group developed the erythropoietin (Epo) enhancer-SV40 promoter system for hypoxia-specific gene expression. In the present study, the activity of the Epo enhancer-SV40 promoter system was further enhanced without significant decrease in its specificity by co-transfection of the hypoxia-inducible factor 1alpha (HIF1alpha) gene. pSV-HIF1alpha was constructed by the insertion of the HIF1alpha cDNA into pSI. At a 1:1 ratio, co-transfection of pSV-HIF1alpha and pEpo-SV-Luc increased the promoter activity of the Epo enhancer-SV40 promoter system, showing at least three times higher gene expression under hypoxia as compared with the pEpo-SV-Luc single-plasmid transfection. Furthermore, co-transfection showed significant hypoxia specificity. Also, co-transfection of pEpo-SV-VEGF with pSV-HIF1alpha showed the enhanced VEGF expression without loss of hypoxia specificity, as compared with pEpo-SV-VEGF single-plasmid transfection. Furthermore, pSV-HIF1alpha induced the endogenous hypoxia-responsive genes such as angiopoietin-1, which would be beneficial for therapeutic angiogenesis. Therefore, with hypoxia specificity and higher gene expression, co-transfection of pSV-HIF1alpha and pEpo-SV-VEGF may be useful for ischemia targeting gene therapy.
用编码血管内皮生长因子（VEGF）的基因进行治疗性血管生成是缺血性疾病的一种潜在治疗方法。然而，VEGF的表达应受到严格调控，以避免诸如肿瘤生长等副作用。此前，我们团队开发了用于缺氧特异性基因表达的促红细胞生成素（Epo）增强子 - SV40启动子系统。在本研究中，通过共转染缺氧诱导因子1α（HIF1α）基因，Epo增强子 - SV40启动子系统的活性进一步增强，且其特异性没有显著降低。通过将HIF1α cDNA插入pSI构建了pSV - HIF1α。以1:1的比例，pSV - HIF1α和pEpo - SV - Luc共转染可提高Epo增强子 - SV40启动子系统的启动子活性，与pEpo - SV - Luc单质粒转染相比，在缺氧条件下基因表达至少高出三倍。此外，共转染显示出显著的缺氧特异性。同样，与pEpo - SV - VEGF单质粒转染相比，pEpo - SV - VEGF与pSV - HIF1α共转染显示VEGF表达增强且不失缺氧特异性。此外，pSV - HIF1α诱导内源性缺氧反应基因如血管生成素 - 1，这对治疗性血管生成有益。因此，由于具有缺氧特异性和更高的基因表达，pSV - HIF1α和pEpo - SV - VEGF共转染可能对缺血靶向基因治疗有用。
