A novel hTERT promoter-driven E1A therapeutic for ovarian cancer.
A novel hTERT promoter-driven E1A therapeutic for ovarian cancer.
复制标题
DOI：
10.1158/1535-7163.mct-09-0056
复制
发表时间：
2009-08
影响因子：
5.7
通讯作者：
Hung MC
中科院分区：
文献类型：
--
作者：
Xie X;Hsu JL;Choi MG;Xia W;Yamaguchi H;Chen CT;Trinh BQ;Lu Z;Ueno NT;Wolf JK;Bast RC Jr;Hung MC
目前，一种既能保留肿瘤特异性表达又能限制毒性的卵巢癌基因治疗策略尚未被开发出来。多年来越来越多的报道表明，与正常细胞相比，癌细胞中人端粒酶活性显著升高。在本研究中，我们对hTERT启动子进行了评估，结果表明，hTERT启动子可以在卵巢癌细胞中优先引导靶基因的表达。但其启动子(HTERT)活性远低于常用的非特异性启动子CMV。为了克服这个问题，我们将hTERT启动子整合到我们最近开发的VISA系统(VP16-Gal4-WPRE集成系统放大器)中，并显著增强了转基因表达。此外，为了进一步将这个肿瘤特异性启动子基因表达系统发展成为一个实用的治疗载体，我们通过这个新的VISA平台表达了E1a(一种具有抗癌特性的腺病毒5型转录因子)。我们证明hTERT-VISA系统特异性地靶向卵巢癌细胞E1a的表达水平高于或相当于常用的CMV启动子，但在正常细胞中几乎保持沉默，因此使其成为一种合适的基因治疗构建体。通过使用这种癌症特异性启动子，限制目标基因在正常细胞/组织中的表达，可以防止CMV启动子引起的潜在毒性。更重要的是，我们通过静脉注射hTERT-VISA-E1a：脂质体纳米粒在动物模型中显示出显著的抗肿瘤活性，毒性要小得多，这表明hTERT-VISA-E1a在基因治疗环境下用于卵巢癌治疗的前景看好。
Currently, an effective gene therapy strategy, which not only retains cancer-specific expression but also limits toxicity, has yet to be developed for ovarian cancer. Mounting reports over the years have shown that human telomerase activity is significantly elevated in cancer cells compared with normal cells. In this study, we evaluated the hTERT promoter and showed that it can direct target gene expression preferentially in ovarian cancer cells. However, its promoter (hTERT) activity is much lower than that of CMV, a commonly used non-specific promoter. To overcome this problem, we have integrated the hTERT promoter into our recently developed VISA system (VP16-Gal4-WPRE integrated systemic amplifier) and dramatically enhanced transgene expression. In addition, to further develop this cancer-specific promoter gene expression system into an applicable therapeutic vector, we expressed E1A (an adenoviral type 5 transcription factor which possesses anti-cancer properties) through this novel VISA platform. We demonstrated that the hTERT-VISA system specifically targeted E1A’s expression to ovarian cancer cells at a level greater than or comparable to the commonly used CMV promoter, yet remained nearly silent in normal cells, and thus making this a suitable gene therapy construct. By using this cancer-specific promoter, which limits target gene expression in normal cells/tissues, potential toxicity induced by the CMV promoter would be prevented. More importantly, we showed significant antitumor activity with much less toxicity in animal models via intravenous delivery of hTERT-VISA-E1A:liposomal nanoparticles, suggesting a promising role of hTERT-VISA-E1A for ovarian cancer treatment under a gene therapy setting.