血管紧张素转化酶Ⅱ对吉西他滨治疗胰腺癌细胞株敏感性的影响

Effect of angiotensin-converting enzyme 2 on the chemosensitivity of gemcitabine in treatment of human pancreatic cancer cell line

目的探讨血管紧张素转化酶Ⅱ(ACE2)在胰腺癌细胞化学治疗中的作用。方法构建质粒,通过脂质体转染技术将质粒DNA转入胰腺癌细胞株SW1990并建立稳定高表达ACE2的胰腺癌细胞克隆。设实验组(转染ACE2表达质粒)、阴性对照组(转染GFP对照质粒)及未转染组,Western印迹法检测转染后各组细胞ACE2蛋白的表达。采用化学治疗药物吉西他滨作用不同处理组细胞,应用MTT法检测细胞增殖变化,流式细胞仪和TUNEL法检测细胞的凋亡变化。结果 50μmol/L吉西他滨干预细胞24 h后,实验组、阴性对照组和未转染组的细胞增殖抑制率分别为(51.2±4.8)%、(24.2±3.3)%和(21.3±2.6)%,3组间差异有统计学意义(P<0.05);流式细胞计数检测实验组细胞凋亡较阴性对照组及未转染组明显增加[(31.2±3.8)%、(17.6±2.3)%、(15.9±1.7)%,P<0.05],TUNEL标记分析发现典型凋亡特征。结论稳定高表达ACE2基因可明显增强SW1990对吉西他滨的治疗敏感性,两者联合应用在胰腺癌治疗中具有潜在的价值。

Objective To investigate the effect of angiotensin-converting enzyme 2 on the chemosensitivity of gemcitabine in treatment of human pancreatic cancer cell line SW1990. Methods ACE2 expression vector was constructed and transfected into pancreatic cancer cell line SW1990. Cells were divided into ACE2 group （SW1990/ACE2, treated with ACE2 expression vector） , negative control group （SW1990/GFP, treated with GFP expression vector） and untreat- ed group （SW1990）. Western blot was used to detect the expression of ACE2 protein in three groups. The cell growth was detected by MTT method. The apoptosis of pancreatic cancer cells was measured by flow cytometry and TUNEL. Results Twenty-four hours after treated with gemcitabine, inhibitory rate of SW1990/ACE2 cells was remarkably higher than that in SW1990 and SW1990/GFP cells （P 〈 0.05）. The cell apoptic rate in SW1990/ACE2 cells was higher than that in SW1990 and SW1990/GFP cells （P 〈 0.05 ）. A similar finding was obtained from the TUNEL analysis. Conclusion Stable overexpression of ACE2 increased the sensitivity of SW1990 cell to chemotherapeutic drugs such as gemcitabine. ACE2 may be a promising candidate for pancreatic cancer gene therapy.