摘要
目的 探讨Notch1基因甲基化与乳腺浸润性导管癌（IDC）及乳腺导管内增生性病变的相关性.方法 用基质辅助激光解析电离时间飞行质谱仪（MALDI-TOF MS）对89例乳腺IDC、20例导管原位癌（DCLS）、11例不典型导管增生（ADH）及20例普通型导管增生（UDH）组织进行Notch1基因甲基化的定量检测.采用免疫组织化学SP法检测上述4种乳腺组织Notch1蛋白的表达.结果 Notch1蛋白在乳腺IDC和DCIS中的阳性率分别为91.0%（81/89）和75.0%（15/20）,两者的表达均高于ADH组（4/11）和UDH组（30.0%,6/20）,差异有统计学意义（P＜0.05）.IDC组Notch1蛋白的高表达与肿瘤的淋巴结转移、病理学分级和TNM分期均呈显著正相关.Notch1基因启动子区CpG_3、CpG_4.5、cpG_8位点的平均甲基化率IDC组低于DCIS、ADH和UDH组,差异有统计学意义（P＜0.0083）.乳腺癌样本Notch1基因CpG_4.5、CpG-10.11、CpG_14.15.16位点的平均甲基化率在无腋窝淋巴结转移组高于有腋窝淋巴结转移组（P＜0.05）;CpG_14.15.16、CpG_18位点的平均甲基化率在乳腺癌不同TNM分期之间,Ⅰ期＜Ⅱ期＜Ⅲ期（P＜0.05）;CpG_1.2和CpG_12.13位点的平均甲基化率高分化组（Ⅰ级）＞中分化组（Ⅱ级）＞低分化组（Ⅲ级）（P＜0.05）;CpG_3、CpG_8、CpG_14.15.16位点的平均甲基化率在ER＋PR＋HER2-组小于ER-PR-HER2＋组（P＜0.05）.结论 在乳腺IDC中存在Notch1基因的广泛低甲基化改变,而其蛋白表达水平则升高.这种负相关关系表明原癌基因Notch1的低甲基化可能是导致其蛋白表达改变的原因,这在乳腺癌的发生和发展中可能具有重要意义.Notch1基因CpG_3、CpG_4.5和CpG_8位点的低甲基化改变与乳腺癌的形成具有相关性,提示该基因特异性CpG位点的低甲基化可能参与了乳腺从良性病变向乳腺癌的发展演进过程.
Objective To explore the relevance between the promoter methylation status of Notch1gene and the invasive ductal carcinoma and ductal hyperplastic lesions of the breast.Methods Methylation status of Notch1 gene in human breast invasive ductal carcinoma（IDC,n=89）,ductal carcinoma in situ （DOS,n=20）,atypical ductal hyperplasia（ADH,,n=11）and usual ductal hyperplasia（UDH,n=20）were quantitatively evaluated by MALDI-TOF MS.The expression of Notch1 protein was detected by immunohistochemical stain（SP method）.Results Positive expression rates of Notch1 protein in IDC and DCIS were 91.0%（81/89）and 75.0%（15/20）,respectively,which were significandy higller than those 0f ADH（4/11）and UDH（30.0%.6/20;P〈0.05）.Notch1 protein expression was correlated significantly with lymph node metastasis,pathological grades and TNM stages of IDC.The mean methylation levels of Notch1 gene at CpG_3,CpC 4.5 and CpG_8 significantly decreased in IDC group compared with those of DCIS.ADH and UDH groups（P〈0.0083）.In breast carcinomas, the mean methylation rates of Notch1 gene at CpG-4.5,CpG-10.11,and CpG_14.15.16 loci in cases with axillary node metastasis were significantly lower than those without axillary node metastasis（P〈0.05）：and the methylation rates at CpG_14.15.16 and CpG_18 lociin stage Ⅰ were lower than that in stage Ⅱ,further lower than that in stage Ⅲ（P〈0.05）;and that in CpG_1.2,CpG_12.13 loci in grade Ⅰ（highly-differentiated group）were higher than that in grade Ⅱ（moderate-differentiated group）and grade Ⅲ（peody-differentiated group） （P〈0.05）;and the methylation rates at CpG_3,CpG_8 and CpG_14.15.16 loci in ER＋ PR＋ HER2-group were lower than that in ER-PR-HER2＋ group（P〈0.05）.Conclusions There is an overall hypomethylation of Notch1 gene in breast invasive ductal carcinomas with corresponding over-expression of Notehl protein.This inverse correlation show that the alteration of protein expression result from hypomethylation oncogene Notch1,and this change may have important significance in breast tumorigenesis and the development.Specific hypomethylation at CpG_3,CpG_4.5 and CpG_8 loci of Notehl gene may play a role in the pathogenesis of breast carcinoma,suggesting the progression and/or malignant transformation from benign glandular lesions of the breast.
出处
《中华病理学杂志》
CAS
CSCD
北大核心
2011年第5期324-329,共6页
Chinese Journal of Pathology
基金
国家自然科学基金（30760072）
广东省医学科研基金（卫生厅）课题（A2008442）
作者简介
通信作者：付欣鸽，510120；E-mail：fuxinge．sh@163．com
