VNP20009“双靶向性”系统在肿瘤治疗中的应用研究

Application of"Double Targeted"System of VNP20009 for Cancer

目的探讨减毒鼠伤寒沙门氏菌VNP20009/单链抗体"双靶向性"系统在肿瘤治疗中的应用价值。方法本研究拟将前期筛选得到的、可特异性靶向卵巢癌标识分子TEM1的单链抗体scFv-78与人源化毒素DNAseⅠ共同构建入鼠伤寒沙门氏菌穿梭质粒pET302中,在VNP20009中表达该蛋白并通过细胞实验评价该治疗系统对肿瘤的靶向效果。结果构建了pET302-Gala-DNAseⅠ-78、pET302-GalaSV40-DNAseⅠ-78、pET302-Gala-M9-DNAseⅠ-78和pET302-Gala-BIF-DNAseⅠ-78一系列表达质粒,通过West blot验证为目的蛋白,该蛋白能彻底降解溶液中的DNA,且特异性与MS1-TEM1细胞相结合。结论将融合蛋白与减毒鼠伤寒沙门氏菌VNP20009相结合,可达到"双靶向"的目的。为肿瘤的靶向治疗提供了新的思路和研究模式。

Objective To investigate the application value of"double targeting"treatment system for Salmonella typhimurium VNP20009/single-chain antibody in tumor therapy.Methods This study intends to construct a single-chain antibody scFv-78 that can be specifically targeted to ovarian cancer marker TEM1 and humanized toxin DNAseⅠinto the shuttle plasmid pET302 of Salmonella typhimurium and express the protein in VNP20009 And evaluate the therapeutic effect of the treatment system on tumors through cell experiments.Results A series of expression plasmids pET302-Gala-DNAseⅠ-78,pET302-Gala-SV40-DNAseⅠ-78,pET302-Gala-M9-DNAseⅠ-78 and pET302-Gala-BIF-DNAseⅠ-78 were constructed,which were verified by Western blot as the target protein,and can be specifically combined with MS1-TEM1 cells,which can completely degrade the DNA in the solution.Conclusion Combining the fusion protein with the attenuated Salmonella typhimurium VNP20009 can achieve the goal of"dual targeting".Provides new ideas and research models for targeted therapy of tumors.