Tumor suppressor gene promoter hypermethylation in serum of breast cancer patients
Tumor suppressor gene promoter hypermethylation in serum of breast cancer patients
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DOI：
10.1158/1078-0432.ccr-04-0597
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发表时间：
2004-09-15
影响因子：
11.5
通讯作者：
Cairns, P
中科院分区：
文献类型：
--
作者：
Dulaimi, E;Hillinck, J;Cairns, P
目的：乳腺癌是美国妇女最常见的恶性肿瘤，也是癌症死亡的第二大原因。引发和驱动癌症的遗传和表观遗传改变可用作检测体液中肿瘤的靶标。乳腺癌患者乳头抽吸物和导管灌洗物中可检测到肿瘤细胞特异性异常启动子高甲基化。在这项研究中，我们检查血清，一种更容易获得的体液，已知含有来自癌症患者的肿瘤DNA，用于基于甲基化的乳腺肿瘤检测。实验设计：我们检测了三个正常未甲基化的具有生物学意义的癌症基因的启动子甲基化状态，PAS相关结构域家族蛋白1A（RASSF 1A），腺瘤性结肠息肉病（APC），和死亡相关蛋白激酶（DAP-激酶）。34例患者包括导管原位癌（CIS）7例，小叶CIS 3例，I期浸润性导管癌5例，II至IV期浸润性导管癌15例，浸润性小叶癌4例。结果：34例乳腺癌组织中有32例（94%）存在一个或多个基因的高甲基化。APC在34例肿瘤中的15例（47%）中高甲基化，RASSF 1A在34例肿瘤中的22例（65%）中高甲基化，DAP激酶在34例肿瘤中的17例（50%）中高甲基化。26例（76%）相应血清DNA启动子甲基化阳性，包括导管CIS、小叶CIS、I期疾病和小叶癌患者。在正常健康女性和炎症性乳腺疾病患者或非肿瘤性乳腺组织标本的血清DNA中，未观察到APC、RASSF 1A或DAP激酶的超甲基化。肿瘤DNA中未甲基化的基因总是被发现在匹配的血清DNA中未甲基化（100%特异性）。结论：肿瘤细胞特异性APC，RASSF 1A和DAP-激酶启动子高甲基化存在于导管CIS，小叶CIS和所有级别和阶段的浸润性乳腺癌。超甲基化可以通过甲基化特异性PCR分析来检测来自适合治愈的浸润前和早期乳腺癌患者的血清DNA。如果在其他研究中得到证实，基于血清（一种容易获得的体液）的高甲基化筛查可能会提高乳腺癌的早期检测。
Purpose: Breast cancer is the most common malignancy in American women and the second leading cause of death from cancer. The genetic and epigenetic alterations that initiate and drive cancer can be used as targets for detection of neoplasia in bodily fluids. Tumor cell-specific aberrant promoter hypermethylation can be detected in nipple aspirate and ductal lavage from breast cancer patients. In this study, we examine serum, a more readily accessible bodily fluid known to contain neoplastic DNA from individuals with cancer, for methylation-based detection of breast neoplasia.Experimental Design: We examined the promoter methylation status of three normally unmethylated biologically significant cancer genes, PAS association domain family protein 1A (RASSF1A), adenomatous polyposis coli (APC), and death-associated protein kinase (DAP-kinase), by sensitive methylation-specific PCR in 34 breast tumor and paired preoperative serum DNA. The 34 patients comprised 7 ductal carcinoma in situ (CIS), 3 lobular CIS, 5 stage I and 15 stage II to IV invasive ductal carcinomas, and 4 invasive lobular carcinomas. Normal and benign tissue and serum control DNA were also examined to determine the specificity of hypermethylation.Results: Hypermethylation of one or more genes was found in 32 of 34 (94%) breast tumor DNA. APC was hypermethylated in 15 of 34 (47%), RASSF1A in 22 of 34 (65%), and DAP-kinase in 17 of 34 (50%) tumors. Twenty-six (76%) of the corresponding serum DNA were positive for promoter hypermethylation, including ductal CIS, lobular CIS, stage I disease, and lobular carcinoma patients. No hypermethylation of APC, RASSF1A, or DAP-kinase was observed in serum DNA from normal healthy women and patients with inflammatory breast disease or nonneoplastic breast tissue specimens. A gene unmethylated in the tumor DNA was always found to be unmethylated in the matched serum DNA (100% specificity).Conclusions: Tumor cell specific promoter hypermethylation of APC, RASSF1A, and DAP-kinase is present in ductal CIS, lobular CIS, and all grades and stages of invasive breast cancer. Hypermethylation can be detected by methylation-specific PCR analysis in serum DNA from patients with preinvasive and early-stage breast cancer amenable to cure. If confirmed in additional studies, hypermethylation-based screening of serum, a readily accessible bodily fluid, may enhance early detection of breast cancer.