Enhanced Safety Profiles of the Telomerase-Specific Replication-Competent Adenovirus by Incorporation of Normal Cell-Specific microRNA-Targeted Sequences
Enhanced Safety Profiles of the Telomerase-Specific Replication-Competent Adenovirus by Incorporation of Normal Cell-Specific microRNA-Targeted Sequences
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DOI：
10.1158/1078-0432.ccr-10-2008
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发表时间：
2011-05-01
影响因子：
11.5
通讯作者：
Mizuguchi, Hiroyuki
中科院分区：
文献类型：
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作者：
Sugio, Kumiko;Sakurai, Fuminori;Mizuguchi, Hiroyuki
目的：溶瘤腺病毒（Ad）已被积极探索作为癌症治疗的潜在药物。在各类溶瘤Ads中，端粒酶特异性复制能力Ad（TRAD）拥有由人端粒酶逆转录酶启动子驱动的E1基因表达盒，在人体临床试验中显示出良好的结果；然而，E1 基因在正常细胞中也有轻微表达，导致正常细胞中 TRAD 的复制和细胞毒性。 实验设计：为了克服这个问题，我们利用了 microRNA (miRNA) 调节的基因表达系统。据报道，miR-143、-145、-199a 或 let-7a 的四个拷贝的互补序列被整合到 E1 基因表达盒的 3'-非翻译区。结果：在构建的 TRAD 变体（本文称为 TRAD）中，含有与 miR-143、-145 或 -199a 互补的序列的 TRAD 表现出与肿瘤细胞中的亲本 TRAD。另一方面，含有miRNA互补序列的TRAD的复制在正常细胞（包括原代正常细胞）中最多被抑制1,000倍。此外，为了抑制肝细胞以及其他正常细胞中 TRAD 的复制，我们构建了包含 miR-199a 和肝脏特异性 miR-122a (TRAD-122a/199aT) 2 个不同互补序列的 TRAD。 TRAD-122a/199aT 在所有检查的正常细胞（包括原代肝细胞）中均表现出病毒复制减少 10 倍以上。结论：这项研究表明，含有与正常细胞特异性 miRNA 互补的序列的溶瘤广告显示出显着改善的安全性，而不会改变肿瘤细胞裂解活性。临床癌症研究； 17(9)； 2807-18。 (C)2011 AACR。
Purpose: Oncolytic adenoviruses (Ad) have been actively pursued as potential agents for cancer treatment. Among the various types of oncolytic Ads, the telomerase-specific replication-competent Ad (TRAD), which possesses an E1 gene expression cassette driven by the human telomerase reverse transcriptase promoter, has shown promising results in human clinical trials; however, the E1 gene is also slightly expressed in normal cells, leading to replication of TRAD and cellular toxicity in normal cells.Experimental Design: To overcome this problem, we utilized a microRNA (miRNA)-regulated gene expression system. Four copies of complementary sequences for miR-143, -145, -199a, or let-7a, which have been reported to be exclusively downregulated in tumor cells, were incorporated into the 3'-untranslated region of the E1 gene expression cassette.Results: Among the TRAD variants (herein called TRADs) constructed, TRADs containing the sequences complementary to miR-143, -145, or -199a showed efficient oncolytic activity comparable to the parental TRAD in the tumor cells. On the other hand, replication of the TRADs containing the miRNA complementary sequences was at most 1,000-fold suppressed in the normal cells, including primary normal cells. In addition, to suppress the replication of the TRADs in hepatocytes as well as other normal cells, we constructed a TRAD containing 2 distinct complementary sequences for miR-199a and liver-specific miR-122a (TRAD-122a/199aT). TRAD-122a/199aT exhibited more than 10-fold reduction in viral replication in all the normal cells examined, including primary hepatocytes.Conclusions: This study showed that oncolytic Ads containing the sequences complementary to normal cell-specific miRNAs showed significantly improved safety profiles without altering tumor cell lysis activity. Clin Cancer Res; 17(9); 2807-18. (C)2011 AACR.