Antitumor activity of an oncolytic adenovirus-delivered oncogene small interfering RNA
Antitumor activity of an oncolytic adenovirus-delivered oncogene small interfering RNA
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DOI：
10.1158/0008-5472.can-06-1617
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发表时间：
2006-10-01
期刊：
影响因子：
11.2
通讯作者：
Tong, Alex W.
中科院分区：
文献类型：
--
作者：
Zhang, Yu-An;Nemunaitis, John;Tong, Alex W.
尽管在动物模型中取得了成功，但由于缺乏最佳的递送平台，使用小干扰RNA（siRNA）的癌症基因治疗受到阻碍。我们研究了可复制的溶瘤腺病毒ONYX-411向人类癌细胞递送突变型K-ras siRNA转基因的适用性。原理验证研究显示，通过siRNA介导的K-ras敲低和ONYX-411介导的癌细胞裂解，可产生叠加的肿瘤生长抑制反应。通过将人HI启动子控制下的K-ras（v12）特异性siRNA（ras-4）发夹结构克隆到ONYX-411缺失的E3 b区中，产生了一种新的构建体，称为Internavec（用于干扰RNA载体）。Internavec在表达相关K-ras 12突变（H79、H441和SW 480）的人癌细胞中获得了类似于10倍的效力增加，如通过达到50%生长抑制（ED 50）所需的有效剂量减少所定义的。Internavec在非恶性上皮细胞中保持减弱。每天瘤内注射Internavec（每天注射5次，每次1 × 10（8）个空斑形成单位）显著降低了s.c. nu/nu小鼠中的H79胰腺癌异种移植物的生长抑制率为85.5%，包括五只小鼠中的三只中的完全生长抑制。亲本ONYX-411或ONYX-411-siRNA（GFP）的效果明显较差（分别为47.8%生长减少，P = 0.03;和44.1%生长减少，P = 0.03）。siRNA（ras）转基因活性有助于细胞周期阻滞，增加细胞凋亡，并显着下调Ras信号相关基因的表达（AKT 2，GSK 3 β，E2 F2和MAP 4K 5）。这些发现表明，Internavec可以通过癌基因敲除和病毒溶瘤对肿瘤细胞产生双管齐下的攻击，从而显着增强抗肿瘤效果。
Despite successes in animal models, cancer gene therapy with small interfering RNAs (siRNA) is hindered by the lack of an optimal delivery platform. We examined the applicability of the replication-competent, oncolytic adenovirus, ONYX-411, to deliver a mutant K-ras siRNA transgene to human cancer cells. Proof-of-principle studies showed an additive tumor growth-inhibitory response through siRNA-mediated K-ras knockdown and ONYX-411-mediated cancer cell lysis. A novel construct, termed Internavec (for interfering RNA vector), was generated by cloning a K-ras(v12)-specific siRNA(ras-4), hairpin construct under the control of the human HI promoter into the deleted E3b region of ONYX-411. Internavec acquired an increase in potency of similar to 10-fold in human cancer cells expressing the relevant K-ras 12 mutation (H79, H441, and SW480), as defined by a reduction in the effective dose needed to achieve 50% growth inhibition (ED50). Internavec remained attenuated in nonmalignant epithelial cells. Daily intratumoral injections of Internavec (five daily injections of 1 x 10(8) plaque-forming units) significantly reduced the growth of s.c. H79 pancreatic cancer xenografts in nu/nu mice by 85.5%, including complete growth suppression in three of five mice. Parental ONYX-411 or ONYX-411-siRNA(GFP) was markedly less effective (47.8% growth reduction, P = 0.03; and 44.1% growth reduction, P = 0.03, respectively). SiRNA(ras) transgene activity contributed to cell cycle blockage, increased apoptosis, and marked down-regulation of Ras signaling-related gene expression (AKT2, GSK3 beta, E2F2, and MAP4K5). These findings indicate that Internavec can generate a two-pronged attack on tumor cells through oncogene knockdown and viral oncolysis, resulting in a significantly enhanced antitumor outcome.