论文部分内容阅读
目的：研究组织特异性表达的胞嘧啶脱氨酶（ＣＤ）基因在裸鼠体内对人类大肠癌和肝细胞癌的治疗作用。方法：将ＣＤ基因修饰的大肠癌ＬｏＶｏ细胞移植到裸鼠体内，观察对全身给予５－氟胞嘧啶（５－ＦＣ）的反应，用含ＣＤ基因的重组病毒产生细胞和５－ＦＣ治疗人肝癌裸鼠模型，并用ＰＣＲ法确定体内基因转移效果，骨髓涂片检查体内基因治疗对造血细胞的影响。结果：转ＣＤ基因对ＬｏＶｏ细胞的致瘤性无影响，全身给予５－ＦＣ治疗６０ｄ，转ＣＤ基因的大肠癌肿瘤明显缩小；ＣＥＡ启动子调控的ＣＤ（ＣＥＡ／ＣＤ）基因修饰的ＬｏＶｏ细胞形成的肿瘤在５－ＦＣ作用下消退。重组病毒在体内可以感染肿瘤、骨髓细胞，给予５－ＦＣ后取得了一定的抗肝细胞癌效果。ＣＥＡ／ＣＤ治疗组未发现明显的骨髓抑制，而ＬＴＲ调控ＣＤ的治疗组出现了明显的骨髓抑制。结论：组织特异性转录调控序列调控的ＣＤ基因体内基因治疗，较普通启动子调控的ＣＤ基因具有明显的安全性和有效性。
Objective: To study the therapeutic effect of tissue-specific cytosine deaminase (CD) gene on human colorectal cancer and hepatocellular carcinoma in nude mice. METHODS: The CD gene-modified colorectal cancer LoVo cells were transplanted into nude mice to observe the systemic administration of 5-fluorocytosine (5-FC). The recombinant virus-producing cells containing the CD gene and 5-FC were used to treat human liver cancer. The nude mice model was used to determine the effect of gene transfer in vivo by PCR and bone marrow smears were used to examine the effects of gene therapy in vivo on hematopoietic cells. RESULTS: The transgene had no effect on the tumorigenicity of LoVo cells. Systemic administration of 5-FC for 60 days resulted in a significant reduction of colorectal cancers with CD gene transfection. The activation of CDA (CEA/CD) gene-modified LoVo cells regulated by CEA promoter was performed. The tumor regressed under 5-FC. Recombinant viruses can infect tumors and bone marrow cells in vivo and achieve a certain anti-hepatoma effect after 5-FC administration. No significant myelosuppression was observed in the CEA/CD treatment group, whereas significant myelosuppression occurred in the LTR-controlled CD treatment group. Conclusion: The in vivo gene therapy of CD genes regulated by tissue-specific transcriptional regulatory sequences is significantly safer and more effective than the CD genes regulated by common promoters.