CEA启动子启动双自杀基因与单自杀基因对Lovo细胞杀伤作用的比较  

Comparison of Killing Role of Double Suicide Gene Suicide Cytosine Deaminase and Thymidine Kinase and Single Suicide Gene with Control of CEA Promoter on Lovo Cells

作　　者：王天宝[1] 汪建平[1] 董文广[1] 钟女奇[1] 周军[1] 

机构地区：[1]中山大学附属第一医院胃肠外科,广东广州510080

出　　处：《中山大学学报（医学科学版）》2005年第3期308-311,共4页Journal of Sun Yat-Sen University:Medical Sciences

基　　金：国家自然科学基金资助项目(39970335)

摘　　要：【目的】探讨CEA启动子(CEApromoter,Cp)启动的双自杀基因胞嘧啶脱氨酶(cytosinedeaminase,CD)与胸苷激酶(thymidinekinase,TK)组织特异性对Lovo结肠癌细胞杀伤作用是否优于单一自杀基因。【方法】以带有Cp、CD与TK的重组腺病毒转染的Lovo细胞作为实验组,未转染者为对照组,5鄄氟胞嘧啶(5鄄fluorocytosine,5鄄Fc)组系列质量浓度:10、8、6、4、2、0滋g/mL;更昔洛韦(ganciclovir,GCV)组系列质量浓度:5、4、3、2、1、0滋g/mL;两药联合应用的系列质量浓度:(10+5)、(8+4)、(6+3)、(4+2)、(2+1)、0滋g/mL。光镜观察细胞形态,噻唑蓝法测定细胞生长抑制率(growthinhibitionrate,GIR)及半数抑制浓度(IC50)。病毒转染的Lovo细胞与未转染的Lovo细胞按不同比例混合培养,给予5鄄Fc5滋g/mL或/和GCV10滋g/mL,噻唑蓝法测定细胞GIR。【结果】对照组5鄄Fc与GCV对细胞的生长抑制作用极低,5鄄Fc组IC50为2400滋g/mL,GCV组为3500滋g/mL。实验组随5鄄Fc与GCV剂量增加,对细胞的杀伤作用明显增加,5鄄Fc组IC50为5.75滋g/mL,GCV组为3.50滋g/mL,两者同时应用相当于5鄄Fc1.90滋g/mL+GCV0.95滋g/mL,细胞对5鄄Fc的敏感性提高417.4倍,对GCV的敏感性提高1000倍。病毒杀伤Lovo细胞具有明显的“旁观者”效应,联合应药组的“旁观者”效应明显高于单独应用组。【结论】双自杀基因细胞毒效应以及“旁观者”效应均高于单一自杀基因。Objective] To investigate if the killing role of double suicide cytosine deaminase (CD) and thymidine kinase (TK) promoted by CEA promoter(Cp) is superior to single suicide gene on Lovo cell. [Methods] Experimental group was the Lovo cell transfected with recombinant adenovirus with CEA promoter(Cp), CD and TK(RA-Cp.C.T), control group was that without RA-Cp.C.T transfection. The series concentration was as fellows:5-Fc group: 10, 8, 6, 4, 2, 0 μg/mL; GCV group: 5, 4, 3, 2, 1, 0 μg/mL; 5-Fc+GCV group:(10+5), (8+4), (6+3), (4+2), (2+1), 0 μg/mL. Cell morphology was observed with light microscope; the growth inhibition rate (GIR) and the inhibition concentration 50 (IC50) were measured with MTT. Lovo cells transfected with RA-Cp.C.T and natural Lovo cells were mixed in different proportion, the dose was 5-Fc 10 μg/mL or/and GCV 5 μg/mL, the GIR was calculated with MTT method. [Results] The killing role of 5-Fc and GCV on Lovo cell without being transfected with RA-Cp.C.T was very low, the IC50 of 5-Fc group was 2 400 μg/mL, and GCV group′s IC50 was 3 500 μg/mL. The GIR of 5-Fc and GCV on Lovo cell, transfected with RA-Cp.C.T, rose up based on their dose. The IC50 of 5-Fc was 5.75 μg /mL, and that of GCV was 3.50 μg/mL. Combining usage of 5-Fc and GCV presented a IC50 of 5-Fc 1.90 μg/mL+GCV 0.95 μg/mL. The killing sensitivity of 5-Fc and GCV on Lovo cell with RA-Cp.C.T were 417.4 and 1 000 folds higher than that on natural Lovo cell. The obvious bystander effect of CD and TK were observed in different mixing proportion levels of Lovo cells with and without RA-Cp.C.T. The bystander effect of 5-Fc+GCV group was higher than that of 5-Fc group or GCV group. [Conclusion] The cytotoxicity and bystander effect of double suicide gene are higher than that of CD or TK.

关 键 词：结肠癌 癌胚抗原基因启动子 胞嘧啶脱氨酶 胸苷激酶 

分 类 号：R735.35[医药卫生—肿瘤]