Department of Urology, College of Medicine, Chungbuk National University, Cheongju, South Korea.
Clin Cancer Res. 2011 Jul 1;17(13):4523-30. doi: 10.1158/1078-0432.CCR-10-2817. Epub 2011 May 13.
Abnormal DNA methylation is associated with many human cancers. The aim of the present study was to identify novel methylation markers in prostate cancer (PCa) by microarray analysis and to test whether these markers could discriminate normal and PCa cells.
Microarray-based DNA methylation and gene expression profiling was carried out using a panel of PCa cell lines and a control normal prostate cell line. The methylation status of candidate genes in prostate cell lines was confirmed by real-time reverse transcriptase-PCR, bisulfite sequencing analysis, and treatment with a demethylation agent. DNA methylation and gene expression analysis in 203 human prostate specimens, including 106 PCa and 97 benign prostate hyperplasia (BPH), were carried out. Further validation using microarray gene expression data from the Gene Expression Omnibus (GEO) was carried out.
Epidermal growth factor-containing fibulin-like extracellular matrix protein 1 (EFEMP1) was identified as a lead candidate methylation marker for PCa. The gene expression level of EFEMP1 was significantly higher in tissue samples from patients with BPH than in those with PCa (P < 0.001). The sensitivity and specificity of EFEMP1 methylation status in discriminating between PCa and BPH reached 95.3% (101 of 106) and 86.6% (84 of 97), respectively. From the GEO data set, we confirmed that the expression level of EFEMP1 was significantly different between PCa and BPH.
Genome-wide characterization of DNA methylation profiles enabled the identification of EFEMP1 aberrant methylation patterns in PCa. EFEMP1 might be a useful indicator for the detection of PCa.
异常的 DNA 甲基化与许多人类癌症有关。本研究的目的是通过微阵列分析鉴定前列腺癌（PCa）中的新型甲基化标志物，并测试这些标志物是否能够区分正常和 PCa 细胞。
使用一组 PCa 细胞系和对照正常前列腺细胞系进行基于微阵列的 DNA 甲基化和基因表达谱分析。使用实时逆转录-PCR、亚硫酸氢盐测序分析和去甲基化剂处理来确认候选基因在前列腺细胞系中的甲基化状态。对 203 例人前列腺标本（包括 106 例 PCa 和 97 例良性前列腺增生（BPH））进行 DNA 甲基化和基因表达分析。使用来自基因表达综合数据库（GEO）的微阵列基因表达数据进行进一步验证。
表皮生长因子富含纤维连接蛋白样细胞外基质蛋白 1（EFEMP1）被鉴定为 PCa 的主要候选甲基化标志物。EFEMP1 的基因表达水平在 BPH 患者的组织样本中明显高于 PCa 患者（P < 0.001）。EFEMP1 甲基化状态在区分 PCa 和 BPH 中的灵敏度和特异性分别达到 95.3%（106 例中的 101 例）和 86.6%（97 例中的 84 例）。从 GEO 数据集，我们证实 EFEMP1 的表达水平在 PCa 和 BPH 之间存在显著差异。
全基因组 DNA 甲基化谱特征分析使我们能够鉴定出 PCa 中 EFEMP1 异常甲基化模式。EFEMP1 可能是检测 PCa 的有用指标。
