Sauthoff H, Heitner S, Rom W N, Hay J G
Department of Medicine, New York University School of Medicine, NY 10016, USA.
Hum Gene Ther. 2000 Feb 10;11(3):379-88. doi: 10.1089/10430340050015851.
Replicating adenoviral vectors are a promising new modality for cancer treatment and clinical trials with such vectors are ongoing. Targeting these vectors to cancer cells has been the focus of research. However, even if perfect targeting were to be achieved, a vector still must effectively kill cancer cells and spread throughout the bulk of the tumor. The adenoviral E1b-19kD protein is a potent inhibitor of apoptosis and may therefore compromise the therapeutic efficacy of an adenoviral vector. In this study we have investigated if an E1b-19kD gene deletion could improve the ability of a replicating adenoviral vector to spread through and kill cancer cells. In several lung cancer cell lines an E1b-19kD-deleted virus (Ad337) induced substantially more apoptosis than did a wild-type virus (Ad309), and tumor cell survival was significantly reduced in three of four cell lines. In addition, the apoptotic effects of cisplatin or paclitaxel were augmented by Ad337, but inhibited by wild-type virus. The number of infectious virus particles in the supernatant of infected cells was increased with Ad337 compared with wild-type virus, indicating enhanced early viral release. Ad337, in contrast to Ad309, induced significantly larger plaques after infection of A549 cells. This well-described large plaque phenotype of an E1b-19kD mutant virus is likely the result of early viral release and enhanced cell-to-cell viral spread. Loss of E1b-19kD function caused only minor cell line-specific increase or decrease in viral yield. We conclude that deletion of the E1b-19kD gene may enhance the tumoricidal effects of a replicating adenoviral vector.
复制型腺病毒载体是一种很有前景的癌症治疗新方法，目前针对此类载体的临床试验正在进行。将这些载体靶向癌细胞一直是研究的重点。然而，即使实现了完美的靶向，载体仍必须有效地杀死癌细胞并扩散到整个肿瘤组织中。腺病毒E1b - 19kD蛋白是一种有效的凋亡抑制剂，因此可能会损害腺病毒载体的治疗效果。在本研究中，我们调查了E1b - 19kD基因缺失是否能提高复制型腺病毒载体在癌细胞中传播和杀伤的能力。在几种肺癌细胞系中，缺失E1b - 19kD的病毒（Ad337）比野生型病毒（Ad309）诱导的凋亡要多得多，并且在四个细胞系中有三个细胞系的肿瘤细胞存活率显著降低。此外，Ad337增强了顺铂或紫杉醇的凋亡作用，但野生型病毒则抑制了这种作用。与野生型病毒相比，Ad337感染细胞的上清液中感染性病毒颗粒的数量增加，这表明早期病毒释放增强。与Ad309相比，Ad337感染A549细胞后诱导出明显更大的噬斑。这种已被充分描述的E1b - 19kD突变病毒的大噬斑表型可能是早期病毒释放和细胞间病毒传播增强的结果。E1b - 19kD功能的缺失仅导致病毒产量在细胞系特异性方面有轻微的增加或减少。我们得出结论，E1b - 19kD基因的缺失可能会增强复制型腺病毒载体的杀瘤效果。
