Hubberstey Andrew V, Pavliv Marta, Parks Robin J
Department of Biological Sciences, University of Windsor, Windsor, Ontario, Canada.
Cancer Gene Ther. 2002 Apr;9(4):321-9. doi: 10.1038/sj.cgt.7700436.
The human adenovirus type 5 (Ad5) early region 1A (E1A) proteins have been shown to have potent antitumor effects, due to their ability to reprogram oncogenic signalling pathways in tumor cells. The success of E1A antitumor therapy in animal models has led to its use in phase I and phase II clinical trials, where liposome-based delivery vehicles are being used to deliver a plasmid encoding E1A. To increase the efficiency of E1A delivery to tumors, we have developed an Ad vector deleted of all viral protein coding sequences (termed helper-dependent Ad vectors, hdAds) with the exception of E1A, designated hdAd-E1A. In culture, this vector mediated high-level expression of E1A gene products. A549 cells, a human lung adenocarcinoma cell line, infected with hdAd-E1A showed a reduced proliferative capacity in adherent culture, and the ability to form colonies in soft agarose was completely abolished. In contrast, A549 infected with an hdAd expressing beta-gal were able to form colonies of a similar size and frequency as uninfected cells. Under serum-depleted conditions, expression of E1A within A549 led to the induction of apoptosis. Finally, A549 cells treated with hdAd-E1A showed approximately 10-fold greater sensitivity to the chemotherapeutic drug cisplatin. Taken together, these data indicate that the use of hdAd provides a simple and effective method to deliver E1A to cancer cells, and results in reduction in the tumorigenic potential of the cells, as well as increasing the cells sensitivity to anticancer drugs.
人5型腺病毒（Ad5）早期区域1A（E1A）蛋白已被证明具有强大的抗肿瘤作用，这是由于它们能够重编程肿瘤细胞中的致癌信号通路。E1A抗肿瘤疗法在动物模型中的成功促使其用于I期和II期临床试验，在这些试验中，基于脂质体的递送载体被用于递送编码E1A的质粒。为了提高E1A递送至肿瘤的效率，我们开发了一种除E1A外删除了所有病毒蛋白编码序列的腺病毒载体（称为辅助依赖型腺病毒载体，hdAds），命名为hdAd-E1A。在培养中，该载体介导了E1A基因产物的高水平表达。感染hdAd-E1A的人肺腺癌细胞系A549在贴壁培养中的增殖能力降低，并且在软琼脂糖中形成集落的能力完全丧失。相比之下，感染表达β-半乳糖苷酶的hdAd的A549能够形成与未感染细胞大小和频率相似的集落。在血清缺乏的条件下，A549细胞中E1A的表达导致细胞凋亡的诱导。最后，用hdAd-E1A处理的A549细胞对化疗药物顺铂的敏感性提高了约10倍。综上所述，这些数据表明使用hdAd提供了一种简单有效的方法将E1A递送至癌细胞，并导致细胞致瘤潜力降低，以及增加细胞对抗癌药物的敏感性。
