Abstract

Tumor-specific promoters and cis-regulatory genetic elements are used for transcriptional control of therapeutic transgene expression in cancer gene therapy. HRE (hypoxia response element) and ARE (antioxidant response element) cis-regulatory elements are targets for HIF1 and Nrf2 transcriptional factors, respectively, and mediate activation of gene transcription in a response to hypoxia and oxidative stress, characteristic of most solid tumors. Due to these features HREs and AREs are used in genetic constructs for cancer gene therapy to provide tumor-specific therapeutic transgene expression or replication of oncolytic adenoviruses. In this work on the basis of the tumor-specific promoter hTERT we have constructed hybrid promoters carrying combinations of HRE and ARE. We showed that upon imitation of hypoxia in human lung cancer cell lines the activity of the hybrid promoter HRE-ARE-hTERT is substantially higher compared to promoters carrying only ARE or HRE. Using in vitro suicide cancer gene therapy with the CD: UPRT/5-FC (cytosine deaminase: uracil phosphoribosyl transferase/5-fluorocytosine) enzyme-prodrug system as a model we showed an enhancement of the cytotoxic effect on human lung cancer cells upon imitation of hypoxia when cytosine deaminase: uracil phosphoribosyl transferase was expressed under the control of the HRE-ARE-hTERT promoter compared to HRE-hTERT and ARE-hTERT promoters. The novel hybrid promoter HRE-ARE-hTERT could be used for transcriptional targeting of therapeutic transgene expression or oncolytic adenovirus replication upon development of novel anti-cancer gene therapeutics.

中文翻译：

---

ARE 和 HRE 顺式调控元件的组合提高了肿瘤特异性 hTERT 启动子的活性

摘要

肿瘤特异性启动子和顺式调节遗传元件用于癌症基因治疗中治疗性转基因表达的转录控制。HRE（缺氧反应元件）和 ARE（抗氧化反应元件）顺式调节元件分别是 HIF1 和 Nrf2 转录因子的靶标，它们介导基因转录激活以响应缺氧和氧化应激，这是大多数实体瘤的特征。由于这些特征，HRE 和 ARE 被用于癌症基因治疗的基因构建体中，以提供肿瘤特异性治疗性转基因表达或溶瘤腺病毒的复制。在这项基于肿瘤特异性启动子 hTERT 的工作中，我们构建了携带 HRE 和 ARE 组合的杂合启动子。我们表明，在模拟人肺癌细胞系缺氧时，与仅携带 ARE 或 HRE 的启动子相比，杂合启动子 HRE-ARE-hTERT 的活性显着更高。使用 CD 的体外自杀癌症基因治疗：UPRT/5-FC（胞嘧啶脱氨酶：尿嘧啶磷酸核糖转移酶/5-氟胞嘧啶）酶-前药系统作为模型，当胞嘧啶脱氨酶：尿嘧啶磷酸核糖转移酶在 HRE-ARE- hTERT 启动子与 HRE-hTERT 和 ARE-hTERT 启动子的比较。在开发新型抗癌基因疗法后，新型杂交启动子 HRE-ARE-hTERT 可用于治疗性转基因表达或溶瘤腺病毒复制的转录靶向。与 HRE-hTERT 和 ARE-hTERT 启动子相比，尿嘧啶磷酸核糖转移酶在 HRE-ARE-hTERT 启动子的控制下表达。在开发新型抗癌基因疗法后，新型杂交启动子 HRE-ARE-hTERT 可用于治疗性转基因表达或溶瘤腺病毒复制的转录靶向。与 HRE-hTERT 和 ARE-hTERT 启动子相比，尿嘧啶磷酸核糖转移酶在 HRE-ARE-hTERT 启动子的控制下表达。在开发新型抗癌基因疗法后，新型杂交启动子 HRE-ARE-hTERT 可用于治疗性转基因表达或溶瘤腺病毒复制的转录靶向。