5-氟胞嘧啶对胞嘧啶脱氨酶基因修饰的胰腺癌细胞凋亡的诱导作用

目的:探讨5-氟胞嘧啶(5-FC)对基因修饰的胰腺癌细胞凋亡的影响及特征。方法: 以腺病毒介导的胞嘧啶脱氨酶(CD)基因转染胰腺癌SW1990细胞,以Western blot检测目标基因蛋白水平表达,通过细胞形态学、脱氧核糖核酸(DNA)凝胶电泳和流式细胞术观察5-FC对表达CD基因的SW1990细胞凋亡的影响作用。结果: 以含CD基因的重组腺病毒转染的SW1990细胞,给予5-FC100 μmol·L^-1, 培养48 h,细胞出现典型的凋亡形态、DNA梯形改变及凋亡峰, 细胞在G₁,S 和G₂/M各期分别为64%、11%和7%,凋亡率达34.6%。结论:5-FC的上述诱导凋亡作用可能是胰腺癌CD基因疗法的重要机制。

Apoptosis induced by 5-fluorocytosine in human pancreatic cancer cells genetically modified to express cytosine deaminase

AIM： To elucidate the pattern of 5-fluorocytosine(5-FC) inducedapoptosis and its role in gene therapy for human pancreatic cancer. METHODS： The human pancreatic cancer SW1990 cells(CEA-producing) were infected with recombinant adenoviruses(Adex1CEA-prCD or Adex1CEA-prZ).Cytosine deaminase(CD) expression was examind by western blot. Apoptosis induced by 5-FC in human pancreatic cancer SW1990 cells genetically modified to express cytosine deaminase was investigated by applying electron microscopy, DNA electrophoresis and flow cytometry analysis techniques. RESULTS： The SW1990 cells infected with Adex1 CEA-prCD were treated with 5-FC at 100 μ.molL-1 for 48 h, cell apoptosis occurred. Typical apoptosis morphological feature appeared and DNA ladder could be demonstrated on DNA electrophoresis. Apoptosis peak was also showed by flow cytometry. Apoptotic cells accounted for 34.6% of the cell population. Cells in G1, S and G2/M phase of cell cycle were 64%, 11% and 7%, respectively. CONCLUSION： The apoptosis induced by 5-FC may be a primary mechanism in CD gene therapy for pancreatic cancer.