Department of Biochemistry, University of Wuerzburg, Wuerzburg D-97074, Germany.
J Transl Med. 2011 Mar 31;9:36. doi: 10.1186/1479-5876-9-36.
Oncolytic viruses show promise for treating cancer. However, to assess therapeutic efficacy and potential toxicity, a noninvasive imaging modality is needed. This study aimed to determine if insertion of the human sodium iodide symporter (hNIS) cDNA as a marker for non-invasive imaging of virotherapy alters the replication and oncolytic capability of a novel vaccinia virus, GLV-1h153.
GLV-1h153 was modified from parental vaccinia virus GLV-1h68 to carry hNIS via homologous recombination. GLV-1h153 was tested against human pancreatic cancer cell line PANC-1 for replication via viral plaque assays and flow cytometry. Expression and transportation of hNIS in infected cells was evaluated using Westernblot and immunofluorescence. Intracellular uptake of radioiodide was assessed using radiouptake assays. Viral cytotoxicity and tumor regression of treated PANC-1tumor xenografts in nude mice was also determined. Finally, tumor radiouptake in xenografts was assessed via positron emission tomography (PET) utilizing carrier-free 124I radiotracer.
GLV-1h153 infected, replicated within, and killed PANC-1 cells as efficiently as GLV-1h68. GLV-1h153 provided dose-dependent levels of hNIS expression in infected cells. Immunofluorescence detected transport of the protein to the cell membrane prior to cell lysis, enhancing hNIS-specific radiouptake (P < 0.001). In vivo, GLV-1h153 was as safe and effective as GLV-1h68 in regressing pancreatic cancer xenografts (P < 0.001). Finally, intratumoral injection of GLV-1h153 facilitated imaging of virus replication in tumors via 124I-PET.
Insertion of the hNIS gene does not hinder replication or oncolytic capability of GLV-1h153, rendering this novel virus a promising new candidate for the noninvasive imaging and tracking of oncolytic viral therapy.
溶瘤病毒在癌症治疗方面显示出巨大的应用潜力。然而，为了评估治疗效果和潜在毒性，需要一种非侵入性的成像方式。本研究旨在探讨是否将人钠碘转运体（hNIS） cDNA 作为标记物插入新型痘苗病毒 GLV-1h153 中，用于病毒治疗的无创成像，会改变病毒的复制和溶瘤能力。
通过同源重组，将 GLV-1h153 从亲本痘苗病毒 GLV-1h68 中修饰，以携带 hNIS。通过病毒噬斑试验和流式细胞术检测 GLV-1h153 对人胰腺癌细胞系 PANC-1 的复制情况。通过 Western blot 和免疫荧光评估感染细胞中 hNIS 的表达和转运。通过放射性摄取试验评估细胞内放射性碘的摄取。还在裸鼠中评估了治疗性 PANC-1 肿瘤异种移植物的病毒细胞毒性和肿瘤消退情况。最后，通过正电子发射断层扫描（PET）利用无载体 124I 放射性示踪剂评估肿瘤的放射性摄取。
GLV-1h153 能够有效地感染、复制和杀伤 PANC-1 细胞，其效率与 GLV-1h68 相同。GLV-1h153 在感染细胞中提供了剂量依赖性的 hNIS 表达水平。免疫荧光检测到该蛋白在细胞裂解前转运到细胞膜，从而增强了 hNIS 特异性放射性碘摄取（P < 0.001）。在体内，GLV-1h153 在消退胰腺癌细胞异种移植物方面与 GLV-1h68 一样安全有效（P < 0.001）。最后，通过肿瘤内注射 GLV-1h153 ，通过 124I-PET 方便地对病毒在肿瘤中的复制进行成像。
hNIS 基因的插入不会阻碍 GLV-1h153 的复制或溶瘤能力，这使得该新型病毒成为一种很有前途的新型候选物，可用于溶瘤病毒治疗的无创成像和追踪。
