血管紧张素转化酶Ⅱ与血管紧张素转化酶在胰腺癌组织中的表达水平变化及相互关系

Expression of angiotensin-converting enzyme 2 and angiotensin-converting enzyme in pancreatic cancer and their relationship

目的检测血管紧张素转化酶Ⅱ(ACE2)和血管紧张素转化酶(ACE)在人胰腺癌组织中的表达情况及相互间关系。方法采用逆转录-聚合酶链反应(RT-PCR)方法检测ACE2与ACE mRNA在14例胰腺癌患者的癌组织、癌旁组织(距癌边缘>5 cm)中的表达及两者的关联性;采用免疫组化法检测ACE2与ACE蛋白在92例胰腺癌患者的癌组织中的表达水平,统计分析两者表达的关联性及ACE2与胰腺癌临床病理特征的关系。结果 ACE2 mRNA在胰腺癌组织中的相对表达量显著低于癌旁组织,ACE mRNA在癌组织中的相对表达量则显著高于癌旁组织(P值均<0.05);ACE2蛋白在胰腺癌组织中的阳性表达率为22.8%(21/92),显著低于癌旁胰腺组织[57.6%(53/92),P<0.05];ACE在胰腺癌中的阳性表达率[85.9%(79/92)]则显著高于癌旁胰腺组织[44.6%(41/92),P<0.05]。胰腺癌组织中ACE2表达在基因及蛋白水平均与ACE表达呈负相关性(r值分别为-0.416和-0.475,P值均<0.05)。胰腺癌组织中ACE2蛋白的表达与胰腺癌的TNM分期密切相关(P<0.05)。结论 ACE2在胰腺癌中表达下调及ACE2与ACE表达比例失衡可能在胰腺癌的发生发展中起重要作用。

Objective To investigate the expression of angiotensin-converting enzyme 2（ACE2） and angiotensin-converting enzyme（ACE） in pancreatic cancer and their relationship.Methods RT-PCR and immunohistochemistry were used to detect the expression of ACE2 and ACE in pancreatic cancer tissues（for mRNA detection,n=14;for protein,n=92） and paired adjacent tumor-free tissues（5 cm apart from cancer）.The association of ACE2 with ACE was analyzed by Spearman correlation.Immunohistochemical data associated with clinical pathological characteristics was also analyzed.Results Both mRNA and protein expression of ACE2 in cancerous tissues were significantly lower than those in paired tumor-free tissues（P0.05）.Whereas both mRNA and protein levels of ACE were significantly higher in cancerous tissues than those in paired tumor-free tissues（P0.05）.There was a negative correlation between ACE2 and ACE in mRNA and protein expression（mRNA r =-0.416,P0.05;protein r =-0.475,P0.01） in cancerous tissues.In addition,down-regulation of ACE2 protein in cancerous tissues was closely related to TNM staging（P0.05）.Conclusion The decreased expression of ACE2 and the imbalance of ACE2/ACE ratio may be involved in the pathogenesis of pancreatic cancer.