Laboratory of Cancer Genetics, Cancer Research Institute of Slovak Academy of Sciences, Bratislava, Slovakia.
Transl Oncol. 2013 Jun 1;6(3):297-304. doi: 10.1593/tlo.13244. Print 2013 Jun.
The aim of this study was to investigate the relationship between the promoter methylation in five cancer-associated genes and clinicopathologic features for identification of molecular markers of tumor metastatic potential and hormone therapy response efficiency in breast cancer. The methylation levels in paraffin-embedded tumor tissues, plasma, and blood cells from 151 sporadic breast cancer patients and blood samples of 50 controls were evaluated by quantitative multiplex methylation-specific polymerase chain reaction. DNA methylation of RAS-association domain family member 1 (RASSF1A), estrogen receptor 1 (ESR1), cadherin 1, type 1, E-cadherin (CDH1), TIMP metallopeptidase inhibitor 3 (TIMP3) and spleen tyrosine kinase (SYK) genes was detected in the tumors of 124, 19, 15, 15, and 6 patients with mean levels of 48.45%, 3.81%, 2.36%, 27.55%, and 10.81%, respectively. Plasma samples exhibited methylation in the same genes in 25, 10, 15, 17, and 3 patients with levels of 22.54%, 17.20%, 22.87%, 31.93%, and 27.42%, respectively. Cumulative methylation results confirmed different spectra in tumor and plasma samples. Simultaneous methylation in tumors and plasma were shown in less than 17% of patients. RASSF1A methylation levels in tumor samples statistically differ according to tumor size (P = .029), estrogen receptor (ER) and progesterone receptor (PR) status (P = .000 and P = .004), and immunohistochemical subtype (P = .000). Moreover, the positive correlation was found between RASSF1A methylation levels and percentage of cancer cells expressing ER and PR. The direct relationship between RASSF1A promoter methylation and expression of ER could aid the prognosis of hormonal therapy response.
本研究旨在探讨五个癌症相关基因启动子甲基化与临床病理特征之间的关系，以期鉴定乳腺癌肿瘤转移潜能和激素治疗反应效率的分子标志物。采用定量多重甲基化特异性聚合酶链反应（PCR）检测 151 例散发性乳腺癌患者石蜡包埋肿瘤组织、血浆和血细胞及 50 例对照者血液中的甲基化水平。在 124 例、19 例、15 例、15 例和 6 例患者的肿瘤中检测到 RAS 关联结构域家族成员 1（RASSF1A）、雌激素受体 1（ESR1）、钙黏蛋白 1 型、E-钙黏蛋白（CDH1）、金属蛋白酶抑制剂 3（TIMP3）和脾酪氨酸激酶（SYK）基因的 DNA 甲基化，其平均水平分别为 48.45%、3.81%、2.36%、27.55%和 10.81%。在 25 例、10 例、15 例、17 例和 3 例患者的血浆样本中检测到相同基因的甲基化，其水平分别为 22.54%、17.20%、22.87%、31.93%和 27.42%。累积甲基化结果证实肿瘤和血浆样本中存在不同的谱。肿瘤和血浆中同时发生甲基化的患者不足 17%。肿瘤样本中 RASSF1A 甲基化水平与肿瘤大小（P =.029）、雌激素受体（ER）和孕激素受体（PR）状态（P =.000 和 P =.004）以及免疫组织化学亚型（P =.000）显著相关。此外，还发现 RASSF1A 甲基化水平与表达 ER 和 PR 的癌细胞百分比之间存在正相关。RASSF1A 启动子甲基化与 ER 表达之间的直接关系有助于预测激素治疗反应的预后。
