构建PEG-3启动子介导的肿瘤靶向基因治疗/报告基因显像监测体系的实验研究

Cancer is one of the major malignant diseases detrimental to human health, gene therapy has emerged as an innovative cancer therapy strategy. However, there still remain some problems such as lower tumor targeting of therapy gene，inefficient and unstable expression of therapy gene, lacking of efficient monitoring. Consequently, it is extremely necessary to develop a gene therapy/monitoring system which has the tumor targeting therapy characteristic, but also can monitor the expression of therapy gene in tumor tissues non-invasively, quantitative and dynamically. In this study, recombinant plasmids will be constructed containing progression-elevated gene-3(PEG-3) promoter as tumor-specific promoter, tumor necrosis factor-related apoptosis-inducing ligand (sTRAIL) gene as therapeutic gene, and herpes simplex virus mutant adenosine kinase gene (HSV1-sr39tk) as reporter gene. Nude mice bearing breast cancer will be transfected with recombinant plasmids by in vivo jetPEI, and the whole-body PET/CT imaging in vivo will be performed with 18F-FHBG as the reporter probe, in order to establish a tumor targeting gene therapy /reporter gene imaging monitoring system which can monitor the expression of tumor-targeting gene therapy non-invasively, quantitative and dynamically.

恶性肿瘤是严重危害人类健康的疾病之一，肿瘤基因治疗已经成为一种极具潜力的治疗方法。目前在肿瘤基因治疗研究中，仍存在着治疗基因肿瘤靶向性不足，治疗基因在肿瘤部位不能高效、稳定、持续表达，缺乏有效监测手段等问题。因此，亟待构建一种既有肿瘤靶向治疗作用，又可无创、实时、定量监测治疗基因表达的治疗/监测体系。本项目拟采用PEG-3肿瘤特异性启动子，可溶性肿瘤坏死因子相关凋亡配体（sTRAIL）编码基因为治疗基因，突变型I型单纯疱疹病毒胸苷激酶基因（ HSV1-sr39tk）为报告基因，构建包含治疗基因和报告基因的重组真核质粒表达载体，采用in vivo jetPEI作为体内转染载体，将重组质粒经尾静脉注射入荷乳腺癌裸鼠模型，以18F-FHBG为报告探针进行PET/CT报告基因显像，以期建立一种可以无创、实时、定量监测治疗基因表达的肿瘤靶向基因治疗/报告基因显像监测体系。