Gene-viral vectors: a promising way to target tumor cells and express anticancer genes simultaneously

肿瘤靶向且高效表达抗癌基因的基因 病毒载体系统(英文)

OBJECTIVE: To develop a new kind of vector system called gene-viral vector, which combines the advantages of gene and virus therapies. METHODS: Using recombinant technology, an anti-tumor gene was inserted into the genome of replicative virus specific for tumor cells. The cell killing effect, reporter gene expression of the green fluorescence protein, anti-tumor gene expression of mouse interleukin-12 (mIL-12) and replication of virus were observed by the methods of cell pathology, fluorescence microscopy, ELISA and electron microscopy, respectively. RESULTS: A new kind of gene-viral vector system of adenovirus, in which the E1b-55 kD gene was deleted but the E1a gene was preserved, was constructed. The vector system, like the replicative virus ONYX-015, replicated and proliferated in tumor cells but not in normal ones. Our vector had an advantage over ONYX-015 in that it carried different kinds of anti-tumor genes to enhance its therapeutic effect. The reporter gene expression of the green fluorescence protein in tumor cells was much better than the adenovirus vector employed in conventional gene the rapy, and the expression in our vector system was as low as or even less than that in the conventional adenovirus gene therapy system. Similar results were observed in experiments with this vector system carrying the anti-tumor gene mIL-12. Replication and proliferation of the virus carrying the mIL-12 gene in tumor cells were confirmed by electron microscopy. CONCLUSIONS: Gene-viral vectors are new vectors with an anti-tumor gene inserted into the genome of replicative virus specific for tumor cells. Because of the specific replication and proliferation of the virus in tumor cells, expression of the anti-tumor gene is increased hundreds to thousands of times. This approach takes full advantages of gene therapy and virus therapy to enhance the effect on the tumor. It overcomes the disadvantages of conventional gene therapy, such as low transfer rate, low gene expression, lack of target tropism, and low anti-tumor activity. We believe that this is a promising means for future tumor treatment.

目的 研究一种结合肿瘤基因治疗与病毒治疗优势的新型肿瘤治疗载体系统 ,即基因 病毒载体系统。方法 利用病毒重组技术将抗癌基因插入肿瘤细胞特异性的增殖病毒基因组中 ,通过细胞病理作用、荧光显微镜、免疫酶链技术及电镜等技术分别观察病毒的杀伤效应、报告基因绿色荧光蛋白、抗癌基因小鼠白细胞介素 12表达量及病毒复制情况。结果 构建了一种新型基因 病毒载体系统 ,该载体系统腺病毒E1b 5 5kDa蛋白缺失 ,保留了腺病毒E1a蛋白。该载体系统具有肿瘤增殖病毒ONYX 0 15相似功能 ,即它可在肿瘤细胞内复制及增殖 ,而在正常细胞内不能复制及增殖 ,从而特异性杀灭肿瘤细胞。它还具有更大的优势 ,即该载体系统可携带各种抗癌基因以进一步提高抗肿瘤的疗效。应用该载体系统携带该报告基因绿色荧光蛋白可使绿色荧光蛋白在肿瘤细胞内高效表达 ,其表达量明显高于传统基因治疗的腺病毒载体系 ,而在正常细胞内低表达 ,与传统腺病毒载体系统相似或更低。应用该载体系统携带抗癌基因小鼠白细胞介素 12 ,也产生类似结果 ,并在电镜中证实该载体系统携带抗癌基因小鼠白细胞介素 12可在肿瘤细胞株中复制及增殖。结论 基因 病毒载体是将抗癌基因插入肿瘤增殖病毒基因组 ,通过肿瘤增殖病毒在肿瘤细胞内特异性复制?