Xu L, Zhao Y, Zhang Q, Li Y, Xu Y
School of Pharmacy, Shanghai JiaoTong University, Shanghai, People's Republic of China.
Gene Ther. 2004 Jun;11(11):894-900. doi: 10.1038/sj.gt.3302254.
Heat-sensitive transgene expression systems have been proposed recently for use in gene therapy to enable both spatial and temporal control of the gene activity. The transgene was put under the control of HSP-related promoters and could be turned on by external heat treatment. While the 'heat activation' phenomenon of the HSP-related promoters in vitro had been well documented, the detailed time response and temporal regulation profile in vivo were not fully understood. We reported here the regulation of transgene luciferase expression in vivo in muscles using a custom-built ultrasound-mediated hyperthermia instrument. The effects of different heating parameters and treatment regimens were evaluated. Optimal activation of gene expression was found at 39 degrees C. Significant tissue damage was observed at 41 degrees C and above, which directly correlated with the greatly reduced gene expression. The gene constructs remained stable and silent in muscle cells, and could be turned on at a later time without losing much activity. Repeated activation was also possible, but required heat treatment at a higher temperature to overcome thermotolerance.
热敏感转基因表达系统最近已被提出用于基因治疗，以实现对基因活性的空间和时间控制。转基因置于热休克蛋白（HSP）相关启动子的控制之下，可通过外部热处理开启。虽然HSP相关启动子在体外的“热激活”现象已有充分记录，但体内详细的时间响应和时间调控概况尚未完全了解。我们在此报告了使用定制的超声介导热疗仪器在体内对肌肉中转基因荧光素酶表达的调控。评估了不同加热参数和治疗方案的效果。发现在39摄氏度时基因表达实现最佳激活。在41摄氏度及以上观察到明显的组织损伤，这与基因表达大幅降低直接相关。基因构建体在肌肉细胞中保持稳定且沉默，并且可以在稍后时间开启而不会损失太多活性。重复激活也是可能的，但需要在更高温度下进行热处理以克服热耐受性。
