53基因及CAR受体对ONYX-015肿瘤杀伤作用的影响

目的:利用肿瘤特异性增殖型腺病毒ONYX-015分别感染具有柯萨奇病毒和腺病毒联合受体(CAR)水平正常、p53正常或突变的,以及CAR水平低下、p53突变的肿瘤细胞株,研究ONYX 015对这些肿瘤细胞的特异性增殖及杀伤能力。方法:以正常的肝细胞株L02作为对照,用细胞病变效应(CPE)实验观察ONYX-015对细胞的选择性杀伤效应;病毒增殖实验检测野生型腺病毒(Ad5)、ONYX 015在多种肿瘤细胞中的增殖能力。结果:ONYX 015对正常的肝细胞L02无杀伤性,但能够有效地杀伤p53突变的肝癌细胞Hep3B、p53正常的肝癌细胞HepG2及肺癌细胞A549,不能杀伤p53突变的人乳腺癌细胞株MDA-MB 231。在CAR受体水平正常的癌细胞株Hep3B、HepG2和A549中,Ad5和ONYX-015均可增殖。在CAR受体水平低下、p53突变的人乳腺癌细胞株MDA-MB 231中,两种病毒均不增殖。结论:CAR受体对ONYX-015的增殖力起着至关重要的作用。在CAR受体水平正常的前提下,无论肿瘤细胞的p53基因正常与否,ONYX-015均可以有效增殖并杀伤细胞;相反,如果CAR受体水平低下,即使该种肿瘤细胞p53基因突变,ONYX-015在该细胞中的增殖力也会受到限制。ONYX-015不杀伤CAR受体及p53基因均正常的正常肝细胞。

The Influence of Coxsackievirus-adenovirus Receptor and p53 Status on the Antitumor Activity of ONYX-015

Objective:To study the selective replication and cytotoxicity of a tumor-specific replicating adenovirus ONYX-015 in tumor cells that were with a wild type of coxsackievirus-adenovirus receptor(CAR) and p53, with a wild CAR and a mutant p53, and that with a mutant type of CAR and p53. Methods:The replicative capability of ONYX-015 and Ad5 was examined by virus replication assay. The cytotoxicity of ONYX-015 was examined by cytopathic effect (CPE) assay in normal and tumor cells, respectively.Results:ONYX-015 was nontoxic to normal hepatocyte cell line L02. Carcinoma cells Hep3B, HepG2 and A549 could be efficiently killed by ONYX-015. Breast carcinoma cells MDA-MB-231 couldn't be killed by ONYX-015. ONYX-015 and its wild type counterpart Ad5 could effectively replicate both in CAR-normal tumor cells, such as HepG2 and A549 cells (p53 normal), and Hep3B cells(p53 mutant). On the contrary, neither of these viruses replicated in CAR-mutant breast carcinoma cells MDA-MB-231.Conclusion:CAR plays more important roles than p53 in the replication of ONYX-015,i.e., ONYX-015 efficiently replicates in CAR-normal tumor cells, and not in tumor cells with mutant-CAR even in the status of p53 mutation. ONYX-015 does not replicate in normal cells.