Zheng Sophy, Ulasov Ilya V, Han Yu, Tyler Matthew A, Zhu Zeng B, Lesniak Maciej S
Division of Neurosurgery, University of Chicago, Chicago, Illinois 60637, USA.
J Gene Med. 2007 Mar;9(3):151-60. doi: 10.1002/jgm.1008.
Malignant gliomas remain refractory to Ad5-mediated gene therapy due to deficiency of the coxsackie adenovirus receptor on tumor cells. The purpose of this study was to evaluate whether changes in adenoviral tropism can enhance gene transfer in the context of malignant glioma.
We have identified several receptors that are over-expressed on tumor cells and created a series of pseudotyped Ad5 vectors that recognize these receptors: Ad5-RGD which binds alpha(v)beta3/alpha(v)beta5 integrins; Ad5/3 which contains adenovirus serotype 3 knob and binds to CD46; Ad5-Sigma which incorporates the reovirus sigma knob and binds to junctional adhesion molecule-1; and Ad5-pk7 which contains the polylysine motif and binds heparan sulfate proteoglycans. We also investigated the Ad5-CAV1 vector, which contains the knob of canine adenovirus type 1, a virus previously shown to infect glioma via an unknown mechanism. In this study, we compared these modified vectors for their ability to promote the expression of luciferase transgene both in vitro and in vivo.
Our results indicate that all five modified vectors attained higher mean luciferase activity vs. control. Among them, Ad5-CAV1 and Ad5-pk7 attained the highest transduction efficiency independent of different tumor lines or infection time. Ad5-Sigma and Ad5-pk7 also demonstrated the least nonspecific infection in normal human astrocytes. Most importantly, Ad5-pk7 achieved 1000-fold increased transgene expression in human glioma xenografts in vivo.
These results indicate that modifications of adenoviral tropism can enhance gene transfer in tumors that are poorly susceptible to adenoviral vectors and warrant further development of Ad5-pk7 for glioma gene therapy.
由于肿瘤细胞上柯萨奇腺病毒受体的缺乏，恶性胶质瘤对腺病毒5型介导的基因治疗仍具有抗性。本研究的目的是评估腺病毒嗜性的改变是否能在恶性胶质瘤的背景下增强基因传递。
我们已经鉴定出几种在肿瘤细胞上过表达的受体，并构建了一系列识别这些受体的假型腺病毒5型载体：结合α(v)β3/α(v)β5整合素的腺病毒5型-RGD；包含腺病毒3型纤突并结合CD46的腺病毒5型/3；整合呼肠孤病毒σ纤突并结合连接黏附分子-1的腺病毒5型-σ；以及包含多聚赖氨酸基序并结合硫酸乙酰肝素蛋白聚糖的腺病毒5型-pk7。我们还研究了腺病毒5型-CAV1载体，其包含犬腺病毒1型的纤突，该病毒先前已被证明可通过未知机制感染胶质瘤。在本研究中，我们比较了这些修饰载体在体外和体内促进荧光素酶转基因表达的能力。
我们的结果表明，与对照相比，所有五种修饰载体均获得了更高的平均荧光素酶活性。其中，腺病毒5型-CAV1和腺病毒5型-pk7在不同肿瘤细胞系或感染时间下均获得了最高的转导效率。腺病毒5型-σ和腺病毒5型-pk7在正常人星形胶质细胞中也表现出最少的非特异性感染。最重要的是，腺病毒5型-pk7在体内人胶质瘤异种移植瘤中实现了转基因表达增加1000倍。
这些结果表明，腺病毒嗜性的修饰可以增强对腺病毒载体敏感性较差的肿瘤中的基因传递，并保证进一步开发腺病毒5型-pk7用于胶质瘤基因治疗。
