胞嘧啶脱氨酶基因治疗人胰腺癌的实验研究

Experimental study on human pancreatic carcinoma treated by cytosine deaminase gene therapy

目的 探讨腺病毒介导的大肠杆菌胞嘧啶脱氨酶基因用于人胰腺癌基因疗法的可行性。方法 将含癌胚抗原 (CEA)启动子的重组腺病毒感染人胰腺癌SW1990细胞和Capan 2细胞以及人宫颈癌Hela细胞 ,用逆转录聚合酶链反应 (RT PCR)和Westernblot检测CD基因在细胞中的表达 ,以MTT法比较细胞对 5 氟胞嘧啶 (5 FC)的敏感性差异。建立胰腺癌裸鼠皮下移植瘤模型 ,观察CD基因的原位治疗效应及安全性。结果 腺病毒介导CD基因仅在分泌CEA的SW1990细胞中呈专一性表达 ,转导CD基因的SW1990细胞体外对 5 FC的敏感性明显提高 ,IC50 低于 10 0 μmol/L ,余者均IC50>10 0 0 μmol/L。体内实验显示CD基因原位转移对裸鼠胰腺癌疗效明显。 结论 CD基因靶向性转导结合前体药 5 FC疗法 ,可能成为人胰腺癌基因治疗的新途径。

Objective To explore the possibility of Escherichia coli cytosine deaminase (CD) gene on human pancreatic carcinoma gene therapy. Methods Recombinant adenoviruses containing a carcinoembryonic antigen (CEA) promoter were transiently introduced into SW1990, Capan 2 and Hela cells, separately. The expression of CD gene mRNA was examined by RT PCR. CD protein level in the transduced cells was analyzed by Western blotting. The sensitivity of the cells to 5 fluorocytosine (5 FC) was determined by MTT assay. Results A specific expression of cytosine deaminase gene by adenovirus mediated transfer exhibited only in SW1990 cells (CEA producing). Transduction of CD gene resulted in significant sensitivity of SW1990 cells to 5 FC. The anticancer effect was seen in vivo in SW1990 xenografts nude mice with in situ CD gene transduction. Conclusion The targeted expression of CD gene combined prodrug 5 FC may be a potential approach for gene therapy for human pancreatic carcinoma.