非转移性细胞-5在结肠癌组织中的表达及其意义

The expression and function of non-metastatic cells 5 in colon cancer

目的 探讨非转移性细胞-5（NME5）基因在结肠癌发生发展中的意义.方法 应用实时荧光定量聚合酶链反应（Real-time PCR）检测35例结肠癌患者肿瘤组织及癌旁组织NME5基因mRNA的表达水平,通过Western blot以及免疫组织化学法分别检测4例及64例结肠癌患者肿瘤组织及癌旁组织NME5的蛋白表达水平.结果 Real-time PCR结果显示,35例样本中19例（54.3％）样本的癌旁组织中NME5 mRNA的表达水平是结肠癌组织的2倍以上,癌旁组织中NME5mRNA的表达水平（14.61 ±2.63）显著高于结肠癌组织（17.86±1.72,P＜0.05）.Western blot结果 显示,4例样本中3例样本的癌旁组织NME5蛋白表达明显高于肿瘤组织.免疫组织化学结果显示,NME5蛋白在正常组织中高表达[70.31％ （45/64）],在肿瘤组织中无表达或弱表达[82.81％（53/64）].NME5的表达水平与肿瘤分期（P＜0.01）和分化（P＜0.01）呈高度负相关.结论 NME5基因在正常组织及早期分化良好的结肠癌组织中较高表达,可能参与抑制结肠癌的发生发展.

Objective To investigate the expression of non-metastatic cells 5 （NME5） gene in colon cancer and to explore its potential role in carcinogenesis and progression of colon cancer.Methods Real-time fluorogenic quantitative polymerase chain reaction （Real-time PCR） was conducted to quantify the expression level of NME5 mRNA in the normal and cancerous tissues from 35 patients with colon cancer.Western blotting analysis and immunohistochemistry was conducted to examine the expression level of NME5 protein in paired normal and cancerous tissues from 4 or 64 patients with colon cancer.Results The results shows that among the 35 paired specimens,19 （54.3%） showed at least a 2-fold increase in NME5 mRNA levels in non-cancerous tissues as compared with those in the colon cancerous tissues.The global expression （△Ct） of NME5 was （14.61 ±2.63） in normal tissue and （17.86 ± 1.72） in cancerous tissue respectively.NME5 mRNA expression in normal tissues was significantly higher than that in the cancerous tissues （P 〈0.05）.Western blotting analysis showed that among 4 paired specimens,3 showed significant increase in NME5 protein levels in non-cancerous tissues compared with those in colon cancerous tissues.Immunohistochemical detection of NME5 among 64 paired specimens showed that 70.31% （45/64） of patients highly expressed NME5 in normal tissues,while 82.81% （53/64） of the patients seldom expressed NME5 in cancerous tissues.Low expression of NME5 was significantly associated with advanced clinical stage index （P〈0.01） and low differentiation grade （P〈0.01）.Conclusion The expression of NME5 was highly expressed in normal tissues and well-differentiated cancerous tissues,and it probably participates in inhibiting carcinogenesis and development of colon cancer.