摘要
目的自杀基因具有能将无细胞毒性的前体药物转化为有细胞毒性作用的药物而使细胞死亡,通过观察大肠杆菌胞嘧啶脱氨酶/氟胞嘧啶(CD/5-FC)自杀基因系统对食管癌EC109细胞杀伤效应及与放射联合应用对食管癌肿瘤细胞协同杀伤效应。方法采用PCR方法从大肠杆菌基因组DNA中扩增出CD基因;构建重组真核载体pcDNA3.1-CD;用脂质体转染法转染EC109细胞;观察CD/5-FC体系对EC109细胞的杀伤效应和旁观者效应及对放射的增敏效应。结果RT-PCR分析结果表明CD基因已转入EC109细胞并表达。离体实验证实5-FC对转CD基因后的食管癌细胞株有明显的细胞毒作用,含5%的转基因食管癌细胞加入5-FC后的细胞存活比率为41.8%±14.2%,低于对照组的94.6%±4.3%结果(t=3.14,P<0.05);加入10%的转基因细胞的存活比率为37.8%±4.4%,低于对照组的95.6%±5.4%结果(t=9.75,P<0.01)。CD/5-FC体系对肿瘤细胞放射增敏效果明显,加前药5-FC及放射组细胞存活曲线低于单纯加前药5-FC对照组或单纯放射对照组,重复测量数据方差分析结果显示F=11.50,P<0.01;治疗组分别与5-FC对照组及单纯放射对照组相比F值分别为4.11、10.53,P值分别<0.05、0.01。结论CD/5-FC体系的旁观者效应和放射增敏效果明显。
Objective As generally known that non-cytotoxic pro-drug can be transformed into cytotoxic drug by suicide gene, this work is to investigate the effect of Coli cytosine deaminase/5-fluorocytosine suicide gene （CD/5-FC） used alone or combined with irradiation in esophageal carcinoma cell line（EC）. Methods CD gene was amplified from Coli DNA genome library with PCR technique, with the eukaryotic vector pcDNA3.1-CD then constructed. EC109 cells were transfected with peDN/u3. 1-CD by liposome method. The eytotoxic effect, bystander effect and radiosensitization effect of CD/5-FC in EC109 was analyzed. Results The transfection of CD gene into EC109 and its transcription was confirmed by RT-PCR method. In vitro, 5-FC showed significantly cytotoxic effect on the EPC cell transfected with CD gene. After adding 5-FC , the survival rate of cultured cell conmining 5 % transfect CD gene cell was 41.8 % ± 14.2% while that in the control group was 94.6 ± 4.3 %, （ t = 3.14, P 〈 0.05）. The survival rate of cultured cell containing 10% transfected CD gene cell was 37.8 ± 4.4% compared to 95.6% ± 5.4% in the control group, （ t = 9.75, P 〈 0.01 ）. CD/5-FC showed significant radiosensitization effect, the survival fraction of CD transfected cell was much lower in 5-FC combined with irradiation, when compared with 5-FC alone and radiotherapy alone group together, （ F=11.50, P 〈 0.01 ）. When it was compared with 5-FC alone group and irradiation alone group separately, the difference was also significant（ F = 4.11, P 〈 0.05 and F10.53, P〈0.01, respectively）. Conclusions Suicide gene CD/5-FC shows conspicuous by-stander effect and mdiosensitization effect.
出处
《中华放射肿瘤学杂志》
CSCD
北大核心
2005年第5期443-446,共4页
Chinese Journal of Radiation Oncology
基金
福建省科技厅自然基金资助项目(C0410042)
