【摘要】 目的探讨尿嘧啶磷酸核糖转移酶(UPRT)基因对胞嘧啶脱氨酶/5-氟胞嘧啶(CD/5-FC)自杀基因系统抗瘤作用的增强效应。方法PCR扩增大肠杆菌UPRT基因,构建原核表达质粒pGEX-UPRT;以电穿孔法将该质粒转入婴儿双歧杆菌,筛选阳性重组菌并鉴定;采用MTT法检测表达的UPRT可否与CD产生抗瘤协同作用。结果重组婴儿双歧杆菌可以正确表达UPRT。体外MTT检测显示CD+UPRT组细胞存活率明显低于对照组(P<0.01),且可使B16-F10鼠黑色素瘤细胞对5-FC杀伤敏感性(IC50=0.015μmol.ml-1)显著提高,是CD组(IC50=0.127μmol.ml-1)的8.5倍。结论婴儿双歧杆菌联合转导UP-RT基因可显著增强CD/5-FC自杀基因系统对鼠黑色素瘤细胞B16-F10的杀伤作用。更多还原

【Abstract】 OBJECTIVE To investigate the enhanced antitumor effect of CD/5-FC by uracil phosphoribosyltransferase（UPRT）,Bifidobacterium infantis were taken as a delivery systerm to transport double suicide gene CD and UPRT to tumors.METHODS The UPRT gene was amplified from Escherichia Coli by PCR and constructed in a expression plasmid pGEX-UPRT.The recombinant plasmid was transferred into Bifidobacterium infantis by electroporation and then identified.The synergistic antitumor effect of coexpression CD and UPRT was determined by MTT method.RESULTS Recombinant Bifidobacterium infantis could express UPRT correctly.The suvival rate of cells administrated CD+UPRT and 5-FC were significantly lower than control（P<0.01） and the 5-FC sensitivity(IC₅₀=0.015 μmol·ml^-1) increased 8.5-folds compared with cells administrated CD alone(IC₅₀=0.127 μmol·ml^-1).CONCLUSION Recombinant Bifidobacterium infantis with UPRT gene can significantly enhance the killing effect of CD/5-FC suicide gene system on melanoma B16-F10 cell of mice.更多还原