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

探讨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效果将通过使用一种利用car独立进入机制的新型嵌合Ad载体得到增强。用Ad35纤维构建了表达单纯疱疹病毒I型胸苷激酶（HSV-tk）的嵌合Ad载体（Ad5/F35）。体外实验表明，Ad5/F35对car -阴性细胞的杀伤效果是Ad5HSV-tk的30倍，对car -阳性细胞的杀伤效果是Ad5HSV-tk的30倍。实验组在体内分为对照组、仅感染GFP组、仅给药GCV组、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) 11组。我们观察到Ad5/F35HSV-tk对car阴性膀胱癌动物模型的生长抑制作用是Ad5HSV-tk的10倍，对car阳性癌症模型的抗肿瘤效果相当。对主要脏器无毒副作用。这一发现表明，Ad5/F35载体可以独立于CAR状态转染膀胱癌细胞，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性膀胱切除术标本中S100A2、S100A4和p53的免疫组化染色。这些蛋白与膀胱癌的分期、分级和预后相关。这些发现提示S100A2、S100A4和p53可以作为基因治疗的靶蛋白。根据结果，我们展示了嵌合腺病毒载体作为膀胱癌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.