重组NIS基因腺相关病毒的制备及其在甲状腺癌细胞系表达

目的探讨钠碘同向转运体（NIS）基因介导的甲状腺癌基因治疗的可行性。方法构建腺相关病毒载体质粒pGA—NIS，并采用磷酸钙沉淀法制备重组NIS基因的腺相关病毒rAAV—NIS，体外感染甲状腺癌细胞系FTC-133、8505C后，通过免疫荧光检测被感染细胞的NIS蛋白表达，并通过摄碘实验及NaClO4摄碘抑制实验验证其表达的NIS蛋白功能和特性。结果成功制备了重组NIS基因的rAAV—NIS，其感染肿瘤细胞所表达的NIS蛋白位于细胞膜上，且具有介导碘摄取的功能，以及被NaClO4抑制的特性，表明与正常甲状腺细胞的NIS具有相同的功能和特性。感染细胞的碘摄取较未感染细胞明显增高。结论rAAV—NIS能介导甲状腺癌细胞的碘摄取，为甲状腺癌NIS基因介导的基因治疗提供了实验依据。

Preparation of a recombinant adeno-associated virus vector encoding the human NIS gene and its expression in thyroid cancer cell lines

Objective To demonstrate the feasibility of thyroid gene therapy by using a adeno-asso-ciated virus vector to deliver the sodium/iodide symporter (NIS) gene into the thyroid tumor cells. Methods The recombinant adeno-associated virus encoding the human NIS gene (rAAV-NIS) was produced by calciumphosphate precipitation. After FTC-133, 8505C cells were infected with rAAV-NIS, the immunoflu orescence and iodide uptake studies as well as inhibited iodide uptake tests were carried out. Results A rAAV encoding the human NIS gene was successfully prepared. Immunofluorescence analysis confirmed the expression of the NIS protein in the tumor cells, and it was localized at the cell surface and possessed a function of iodine uptake as well as suppression by perchlorates similar to the function and character with normal thyroid cell. Conclusion rAAV-NIS is very efficient in triggering iodide uptake by infected tumor cells, and it outline the potential of this novel cancer gene therapy approach (or a targted radiotherapy.