A truncated minimal-E1a gene with potency to support adenoviral replication mediates antitumor activity by down-regulating Neu expression and preserving Rb function
A truncated minimal-E1a gene with potency to support adenoviral replication mediates antitumor activity by down-regulating Neu expression and preserving Rb function
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DOI：
10.1016/j.cbi.2009.06.002
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发表时间：
2009-09-14
影响因子：
5.1
通讯作者：
Su, Changqing
中科院分区：
文献类型：
--
作者：
Fang, Lin;Huang, Yao;Su, Changqing
溶瘤腺病毒能够感染、复制和裂解癌细胞。在腺病毒感染和复制中，野生型E1a基因(WE1a)介导多种遗传事件，促进病毒复制，发挥抗肿瘤作用。为了提高其抗肿瘤效果和优化其安全性，我们对wE1a基因进行了操作，通过氨基酸残基的缺失和突变设计了720个碱基的截短最小E1a(ME1a)。将mE1a基因整合到hTERT启动子控制的腺病毒中，构建成载体AdDC315-mE1a。感染该病毒的多种癌细胞株表达mE1a蛋白，与正常细胞株相比，Neu蛋白表达显著下调。ME1a与Rb蛋白的结合亲和力也较低，保留了Rb的肿瘤抑制功能。ME1a的表达使腺病毒在癌细胞中具有高而稳定的复制比率(感染后48小时约为125-8500倍，感染后96小时约为180-10,900倍)。此外，mE1a支持的溶瘤腺病毒在裸鼠肝癌移植瘤中诱导更高的癌细胞凋亡率、更强的细胞周期停滞和更有效的抗肿瘤效果。结论：截短的最小mE1a基因可作为肿瘤抑制基因，可用于构建溶瘤腺病毒载体，用于多种肿瘤的基因治疗。(C)2009爱思唯尔爱尔兰有限公司。保留所有权利。
Oncolytic adenovirus is capable of infecting, replicating in and lysing cancer cells. In adenovirus infection and replication, the wild type E1a gene (wE1a) mediates various genetic events to facilitate viral replication and exert antitumor effect. To enhance its antitumor efficacy and optimize its safety, we manipulated the wE1a gene and designed a 720-bp truncated minimal-E1a (mE1a) by deletions and mutations of amino acid residues. The mE1a gene was incorporated in an adenovirus under the control of hTERT promoter, giving the vectoi-AdDC315-mE1a. A variety of cancer cell lines infected with the virus expressed the mE1a protein and showed considerable down-regulation in Neu protein expression as compared to normal cell lines. mE1a also had a lower binding affinity to the Rb protein, preserving the Rb tumor suppressive function. The mE1a expression allowed efficient adenovirus replication with high and stable replication ratios in cancer cells (about 125- to 8500-fold higher at 48 h and 180- to 10,900-fold higher at 96 h post-infection). Further, the mE1a-supported oncolytic adenovirus induced higher cancer cell apoptosis, stronger cell cycle arrest and more effective antitumor efficacy in hepatocarcinoma xenografts in nude mice. In conclusion, the truncated minimal mE1a can act as a tumor inhibitor gene, and may be used to construct oncolytic adenovirus vectors for use in gene therapy of a variety of cancers. (C) 2009 Elsevier Ireland Ltd. All rights reserved.