涎腺腺样囊性癌组织中E-钙黏蛋白的表达及临床意义

目的 研究E-钙黏蛋白在涎腺腺样囊性癌(SACC)中表达水平、CDH1甲基化状态及临床意义.方法 用免疫组化的方法检测E-钙黏蛋白在SACC及正常涎腺组织中的表达,并用实时荧光甲基化特异性PCR分析CDH1甲基化状态.结果 与正常涎腺组织相比,E-钙黏蛋白在SACC表达低,差异有统计学意义(100.0％比55.6％,P＜0.05),E-钙黏蛋白表达与组织病理学类型、T-分期、神经侵犯、淋巴结转移及远处转移相关(P＜0.05);而与性别、年龄及肿瘤位置无关.30例E-钙黏蛋白表达阳性的SACC标本中,有3例标本检测到CDH1部分甲基化,24例E-钙黏蛋白表达阴性的SACC标本中,23例标本中检测到CDH1完全甲基化,经Spearman等级相关分析提示,随着CDH1基因甲基化增高,E-钙黏蛋白表达减弱,两者在SACC中呈负相关(r=-0.483,P＜0.001).结论 CDH1基因通过甲基化下调E-钙黏蛋白表达,其表达水平与SACC淋巴结转移、神经侵犯及远处转移等相关,这对评估SACC恶性程度及预后具有一定临床价值.

Expression and significance of E-cadherin in adenoid cystic carcinoma of salivary glands

Objective To examine the expression of E-cadherin and the methylation status of CDH1 and explore their clinical significance in salivary adenoid cystic carcinoma (SACC).Methods The expression of E-cadherin was detected by the immunohistochemical method.And the methylation of CDH1 gene promoter 5'-CpG island was analyzed by real-time methylation-specific polymerase chain reaction ( realtime MSP) in salivary adenoid cystic carcinoma and normal salivary gland tissue respectively.Results The expression rate of E-cadherin was lower in SACC than that in normal salivary gland tissue ( 100.0％ vs 55.6％,P ＜ 0.05).And the expression of E-cadherin was associated with different histopathological types,T-stage,nerve invasion,lymphatic and distant metastasis (P ＜ 0.05).However,there was no correlation between the expression of E-cadherin and gender,age and tumor location.Partial methylation of CDH1 was detected in 3 of 30 cases with a positive expression of E-cadherin and full methylation of CDH1 in 23 of 24 cases with a negative expression of E-cadherin.There was a negative correlation between the expression of Ecadherin and the methylation of CDH1 in salivary adenoid cystic carcinoma ( r =- 0.483,P ＜ 0.001 ).Conclusion The down-regulation of E-cadherin,as modulated by the methylation of CDH1,may contribute to nerve invasion,lymphatic and distant metastasis in SACC.Thus it may be used as a biological indicator of malignancy and prognosis.