Chimeric adenovirus vector enhances HSV-tk gene therapy for bladder cancer.

我们研究了膀胱癌的新治疗方式。我们测试了腺病毒（Ad）介导的膀胱癌基因治疗的转导功效将通过使用利用CAR非依赖性进入机制的新型嵌合Ad载体来增强。将腺病毒35（Ad35）的纤维连接到腺病毒5（Ad5）的骨架上，构建了表达单纯疱疹病毒Ⅰ型胸苷激酶（HSV-tk）的嵌合腺病毒载体（Ad5/F35）。在体外实验中，在CAR阴性细胞中的细胞死亡方面，具有HSV-tk的Ad5/F35比Ad5HSV-tk有效多达30倍，并且在CAR阳性细胞中同样有效。体内实验组分为对照组、GFP感染组、GCV组、Ad5HSV-tk（5 × 10^8PFU）、Ad5F35HSV-tk（1 × 10^8，5 × 10^8，1 × 10^9PFU）、Ad5HSV-tk/GCV（5 × 10^8PFU）、Ad5F35HSV-tk/GCV（1 × 10^8，5 × 10^8，1 × 10^9PFU）共11组。我们观察到在CAR阴性膀胱癌动物模型的生长抑制中，Ad5/F35HSV-tk的治疗效果是Ad5HSV-tk的10倍，在CAR阳性癌症模型中具有相当的抗肿瘤功效。无主要脏器毒性及毒副作用。这一发现表明Ad5/F35载体转导的膀胱癌细胞不依赖于CAR状态，并增强了CAR阴性膀胱癌的HSV-tk自杀基因治疗。此外，我们还研究了膀胱癌根治术标本中S100A2，S100A4和p53的免疫组化染色。这些蛋白与膀胱癌的分期、分级及预后有关。这些结果提示S100A2、S100A4和p53可能作为基因治疗的靶蛋白。根据这些结果，我们展示了使用嵌合腺病毒载体作为膀胱癌的靶向特异性治疗的潜在替代方案。

We investigated the new treatment modality for bladder cancer. We tested that the transduction efficacy of adenovirus (Ad)-mediated bladder cancer gene therapy would be enhanced with the use of a novel chimeric Ad vector that utilizes a CAR-independent entry mechanism. A chimeric Ad vector expressing herpes simplex virus I thymidine kinase (HSV-tk) was constructed by Ad35 fiber into an Ad5 backbone (Ad5/F35). In vitro experiment Ad5/F35 with HSV-tk was up to 30 times more effective than Ad5HSV-tk in terms of cell death in CAR-negative cells and equally efficient in CAR-positive cells. Experimental group in vivo was categorized as 11 groups consisted of control, GFP infection only, GCV administration only, Ad5HSV-tk (5×10^8PFU), Ad5F35HSV-tk (1×10^8, 5×10^8, 1×10^9 PFU), Ad5HSV-tk/GCV (5×10^8PFU), Ad5F35HSV-tk/GCV (1×10^8, 5×10^8, 1×10^9 PFU). We observed a 10-fold treatment effect with Ad5/F35HSV-tk over Ad5HSV-tk in growth suppression of CAR-negative bladder cancer animal models with comparable anti-tumor efficacy in CAR-positive cancer models. There were no side effect and toxicity in major organs. This finding demonstrates that the Ad5/F35 vector transduced bladder cancer cells independently of CAR status and augments HSV-tk suicide gene therapy in CAR-negative bladder cancer.In addition, we also investigated immunohistochemical staining using S100A2, S100A4 and p53 in bladder cancer specimens taken form radical cystectomy. These proteins were associated with bladder cancer stage, grade and prognosis. These findings suggested that S100A2, S100A4 and p53 would play a role as target protein for gene therapy. According to the results, we demonstrated potential alternative as target specific treatment for bladder cancer using chimeric adenovirus vector.