使用热休克蛋白基因启动子调控靶基因在肿瘤局部表达

Using Hsp70 promoter to regulate target gene expression in tumor

目的 利用人热休克蛋白基因启动子结合加热选择性诱导目的基因在肿瘤局部表达 ,建立肿瘤基因治疗新方法。方法 分离不同大小的人热休克蛋白 70基因 5’端调控顺序作为启动子 ,以绿色荧光蛋白 (GFP)作报告基因 ,构建热诱导型GFP表达质粒。转染体外培养的肿瘤细胞 ,或将稳定转导GFP表达质粒的肿瘤细胞移植到大鼠皮窗内 ,或将热诱导型GFP腺病毒注射到肿瘤内 ,加热后直接利用荧光显微镜观察GFP表达水平。结果 40 0bp人热休克蛋白 70基因 5’端调控顺序背景表达水平低 ,加热后可被显著激活 ,能作为启动子有效驱动下游目的基因的表达。GFP作报告基因使体内外肿瘤细胞内目的基因的表达水平仅通过荧光显微镜便能直接观察到。结论 利用热诱导型启动子结合加热能选择性诱导目的基因在肿瘤局部表达 ,为肿瘤基因治疗提供了一种新方法。

Objective To regulate gene expression in the desired tumor cells both in vitro and in vivo. Methods Heat inducible green fluorescent protein (GFP) expression plasmid and adenovirus were built by using different sizes of 5′ end regulating sequence from human heat shock protein (Hsp) gene as promoter and GFP cDNA as report gene. GFP expression turned on by heating was observed in the cultured cells and the tumor grown in the dorsal skin window chamber. Results A 400bp of Hsp gene 5′ end regulating sequence can be activated by heating and it can drive report gene expression effectively both in vitro and in vivo. Conclusions Heating can selectively induce gene expression in the targeted tumor. It provides an useful tool for cancer gene therapy because it possibly maximizes tumor cell killing and minimizes normal tissue damage.