Authors' Affiliations: Departments of Molecular Medicine and Urology and Institute of Pathology, Aarhus University Hospital, Aarhus, Denmark; Institute of Surgical Pathology, University Hospital Zurich, Zurich, Switzerland; Department of Urology, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany; Institute of Biomedical Technology and BioMediTech, University of Tampere and Tampere University Hospital, Tampere, Finland; Departments of Oncology and Pathology and Medical Epidemiology and Biostatistics, Karolinska Institute, Stockholm, Sweden.
Clin Cancer Res. 2014 Apr 15;20(8):2169-81. doi: 10.1158/1078-0432.CCR-13-2642.
Available tools for prostate cancer diagnosis and prognosis are suboptimal and novel biomarkers are urgently needed. Here, we investigated the regulation and biomarker potential of the GABRE∼miR-452∼miR-224 genomic locus.
GABRE/miR-452/miR-224 transcriptional expression was quantified in 80 nonmalignant and 281 prostate cancer tissue samples. GABRE∼miR-452∼miR-224 promoter methylation was determined by methylation-specific qPCR (MethyLight) in 35 nonmalignant, 293 prostate cancer [radical prostatectomy (RP) cohort 1] and 198 prostate cancer tissue samples (RP cohort 2). Diagnostic/prognostic biomarker potential of GABRE∼miR-452∼miR-224 methylation was evaluated by ROC, Kaplan-Meier, uni- and multivariate Cox regression analyses. Functional roles of miR-224 and miR-452 were investigated in PC3 and DU145 cells by viability, migration, and invasion assays and gene-set enrichment analysis (GSEA) of posttransfection transcriptional profiling data.
GABRE∼miR-452∼miR-224 was significantly downregulated in prostate cancer compared with nonmalignant prostate tissue and had highly cancer-specific aberrant promoter hypermethylation (AUC = 0.98). Functional studies and GSEA suggested that miR-224 and miR-452 inhibit proliferation, migration, and invasion of PC3 and DU145 cells by direct/indirect regulation of pathways related to the cell cycle and cellular adhesion and motility. Finally, in uni- and multivariate analyses, high GABRE∼miR-452∼miR-224 promoter methylation was significantly associated with biochemical recurrence in RP cohort 1, which was successfully validated in RP cohort 2.
The GABRE∼miR-452∼miR-224 locus is downregulated and hypermethylated in prostate cancer and is a new promising epigenetic candidate biomarker for prostate cancer diagnosis and prognosis. Tumor-suppressive functions of the intronic miR-224 and miR-452 were demonstrated in two prostate cancer cell lines, suggesting that epigenetic silencing of GABRE∼miR-452∼miR-224 may be selected for in prostate cancer.
用于前列腺癌诊断和预后的现有工具并不理想，迫切需要新的生物标志物。在此，我们研究了 GABREmiR-452miR-224 基因组位点的调控和生物标志物潜力。
在 80 份非恶性和 281 份前列腺癌组织样本中定量测定 GABRE/miR-452/miR-224 的转录表达。通过甲基化特异性 qPCR（MethyLight）在 35 份非恶性、293 份前列腺癌[根治性前列腺切除术（RP）队列 1]和 198 份前列腺癌组织样本中确定 GABREmiR-452miR-224 启动子甲基化。通过 ROC、Kaplan-Meier、单变量和多变量 Cox 回归分析评估 GABREmiR-452miR-224 甲基化的诊断/预后生物标志物潜力。通过细胞活力、迁移和侵袭测定以及转染后转录谱数据的基因集富集分析（GSEA）研究 miR-224 和 miR-452 在 PC3 和 DU145 细胞中的功能作用。
与非恶性前列腺组织相比，GABREmiR-452miR-224 在前列腺癌中显著下调，并且具有高度癌症特异性的异常启动子高甲基化（AUC = 0.98）。功能研究和 GSEA 表明，miR-224 和 miR-452 通过直接/间接调节与细胞周期和细胞黏附及运动相关的途径，抑制 PC3 和 DU145 细胞的增殖、迁移和侵袭。最后，在单变量和多变量分析中，RP 队列 1 中高 GABREmiR-452miR-224 启动子甲基化与生化复发显著相关，该结果在 RP 队列 2 中得到了成功验证。
GABREmiR-452miR-224 位点在前列腺癌中下调且发生高甲基化，是一种用于前列腺癌诊断和预后的新的有希望的表观遗传候选生物标志物。在两种前列腺癌细胞系中证明了内含子 miR-224 和 miR-452 的肿瘤抑制功能，表明 GABREmiR-452miR-224 的表观遗传沉默可能在前列腺癌中被选择。
