AdKDR-CDglyTK融合基因系统治疗胰腺癌的实验研究

目的 观察腺病毒介导的KDR启动子驱动的CD/TK融合双自杀基因系统(以下简称为AdKDR-CDglyTK)对胰腺癌的治疗作用.方法 采用培养细胞移植法,将人胰腺癌细胞系Capan-2接种于裸鼠背部皮下,建立裸鼠人胰腺癌移植瘤模型.将20只裸鼠随机分为4组,每组5只.分组方法:Ⅰ组:注射重组腺病毒AdKDR-CDglyTK与前药5-FC与GCV;Ⅱ组:仅注射前药5-FC与GCV;Ⅲ组:仅注射重组腺病毒AdKDR-CDglyTKⅣ组:空白对照,不施加任何处理.重组腺病毒AdKDR-CDglyTK采用瘤体内多点注射,5-FC与GCV给药方法采用腹腔内注射的方法,观察各组小鼠的生存状况及肿瘤体积、瘤重、肿瘤生长抑制率、常规病理等指标;应用透射电镜观察细胞超微结构,用TUNEL法检测细胞凋亡率,比较观察各治疗组的治疗效果;并对各组的肿瘤组织行RTPCR的检测,以了解有无双自杀基因CDglyTK的表达.结果 第Ⅰ组裸鼠移植瘤的生长显著受到抑制,第Ⅱ、Ⅲ、Ⅳ组肿瘤生长情况无明显差别.第Ⅰ组肿瘤细胞凋亡指数为(34.20±4.60)%,较对照组显著增加(P=0.00).结论 AdKDR-CDglyTK联合前药5-FC及GCV对人胰腺癌Capan-2细胞具明显的抑制作用,并且诱导裸鼠体内人胰腺癌Capan-2细胞的凋亡.其可能的机制是通过下调凋亡抑制基因Bcl-2的表达.

Treatment of human pancreatic cancer with adenovirus-mediated fusion gene system driven by KDR promoter in nude mice

Objective To investigate the curative effect of the adenovirus-mediated fusion gene system driven by KDR promoter (AdKDR-CDglyTK) on a model of pancreatic cancer. Methods By using transplantation of the cultivated cells, human pancreatic cell line Capan-2 was injected subcutaneously on the back of nude mice to establish the animal model of the pancreatic cancer. Twenty nude mice were divided randomly and equally into four groups. The mice in group Ⅰ were injected with AdKDR-CDglyTK and 5-FC/GCV, those in group Ⅱ were injected with 5-FC/GCV, those in group Ⅲwere injected with AdKDR-CDglyTK and those in group Ⅳ received no any injection. AdKDR-CDglyTK was injected directly into the tumor and 5-FC/GCV was given by intraperitoneal injection. The observing parameters included common status, tumor bulk, tumor weight, inhibition rate of tumor growth, pathology, immunohistochemistry and treatment effect in each group. Electron microscopy was performed to observe the pathological changes of cells. The apoptotic cells in tumor were detected using the TUNEL assay. The expression of CDglyTK in tumors from each group was examined by RT-PCR. Results Tumor growth was dramatically inhibited in group Ⅰ. Tumor growth has no significant difference among groupⅡ , group Ⅲ and group Ⅳ. The apoptotic rate (34.20±4.60)% was significantly increased in group Ⅰ (F= 243. 22, P= 0. 00) and it had no significant difference among groupⅡ , group Ⅲ and group Ⅳ (P＞0.05). Conclusion AdKDR-CDglyTK with 5-FC/GCV can obviously inhibit the growth of human KDR-expressing pancreatic cell line Capan-2 and induce the cell apoptosis in vivo. The probable molecular mechanism lies in the facts that the system can cause a decline in the level of Bcl-2.