Oncolytic viral therapy for disseminated peritoneal ovarian cancer using a novel replication-competent herpes simplex virus type 1 mutant in mice.

我们制备了两株HSV-1减毒突变株。一个是HSV-1突变体hrR3，另一个是新的具有复制能力的HSV-1突变体HR522；该病毒表达lacZ报告基因，在感染细胞中诱导合胞体形成。我们比较了HR522与紫杉醇和hrR3对携带人卵巢癌细胞的裸鼠的治疗效果。我们还研究了前药更昔洛韦（GCV）对这些单纯疱疹病毒介导的治疗的影响。用高滴度hrR3 （5 × 10^7斑块形成单位；PFU）处理的小鼠的存活时间比给紫杉醇组明显延长（p<0.0001； Log-Rank检验）。虽然高滴度HR522治疗组（5 × 10^7 PFU）小鼠的生存期与紫杉醇治疗组相比没有显著延长（p=0.212； Log-Rank检验），但GCV显著增强了HR522给药的疗效（p<0.005；与紫杉醇相比；Log-Rank检验）。用5-溴-4-铬-3-吲哚基-β- d -半乳糖苷（X-gal）组织化学方法显示，lacZ基因产物在hr522治疗的肿瘤中也表现出凋亡变化。另一项研究表明，HSV-1株HF的克隆衍生物在免疫功能动物模型中非常有效地治疗了腹膜播散性肿瘤，并且所有存活的小鼠都获得了对肿瘤细胞再攻击的抵抗力。HF克隆10在体外诱导合胞体形成。在9只接受治疗的小鼠中，有8只小鼠在肿瘤注射后连续给予hf克隆10，达到了90天以上的长期生存，没有任何疾病迹象。提示HF克隆10治疗腹膜播散性肿瘤可诱导特异性抗肿瘤免疫应答。我们发现克隆10在UL和UL/IRL连接处右端缺失39kbp，导致UL 56表达缺失。此外，在基因组的左端观察到23kbp的缺失和广泛的重排。

We prepared two attenuated mutant HSV-1 strains. One is an HSV-1 mutant, hrR3, and another is a new replication competent HSV-1 mutant, HR522 ; this virus, expressing the lacZ reporter gene, induces syncytium formation in infected cells. We compared the efficacy of HR522 with Taxol and hrR3 in the treatment of nude mice harboring human ovarian cancer cells. We also examined the effect of the prodrug ganciclovir (GCV) on the treatment mediated by these HSVs. The survival of mice treated with a high titer hrR3 (5x10^7 plaque-forming units ; PFU) was significantly prolonged as compared to the group given Taxol (p<0.0001 ; Log-Rank test). Although the survival of mice treated with high titer HR522 (5x10^7 PFU) was not significantly prolonged compared with Taxol-treated group (p=0.212 ; Log-Rank test), GCV markedly enhanced the efficacy of HR522 administration (p<0.005 ; vs Taxol ; Log-Rank test). The lacZ gene product, visualized using 5-brorno-4-chrolo-3-indoryl-β-D- galactopyranoside (X-gal) histochemistry, was detected in HR522-treated tumors in areas also exhibiting apoptotic changes. Another study demonstrated that a clonal derivative of HSV-1 strain HF done 10 very effectively treated peritoneally disseminated neoplasm in an immunocompetent animal model and that all of survived mice acquired resistance to rechallenge of tumor cells. HF clone 10 induces syncytia formation in vitro. A sequential administration ofHF clone 10 attained a long-term survival over 90 days after tumor injection in 8 of the 9 treated mice without any signs of diseases. The results suggested that treatment of peritoneally disseminated tumor with HF clone 10 induced a specific anti-tumor immune response. We found that clone 10 has a deletion of 39kbp in the right end of UL and UL/IRL junction, resulting in the loss of UL 56 expression. Moreover, a 23kbp deletion and extensive rearrangement were observed in the left end of the genome.