Ewing's sarcoma: an analysis of miRNA expression profiles and target genes in paraffin-embedded primary tumor tissue. Ewing's sarcoma: an analysis of miRNA expression profiles and target genes in paraffin-embedded primary tumor tissue

The molecular mechanism responsible for Ewing Sarcoma (ES) remains largely unknown. This study compared global miRNA expression in biopsies from 20 ES patients, affected by primary untreated tumors, with miRNA expressed in normal human mesenchymal stromal cells (MSCs) by microarray analysis. A miRTarBase database was used to identify the predicted target genes for differentially-expressed miRNAs. The miRNAs microarray analysis revealed distinct patterns of miRNA expression between ES biopsies and normal MSCs. 58 of the 954 analyzed miRNAs were significantly differentially expressed in ES samples compared to MSCs. Moreover, the qRT-PCR analysis, carried out on three selected miRNAs, showed that miR-181b, miR-1915 and miR-1275 were significantly aberrantly-regulated, confirming the microarray results. Bio-database analysis identified BCL-2 as a bona fide target gene of the miR-21, miR-181a, miR-181b, miR-29a, miR-29b, miR-497, miR-195, miR-Let-7a, miR-34a. Using paraffin-embedded tissues from ES, this study has identified several potential target miRNAs and one gene that might be considered novel critical biomarkers for ES pathogenesis. Overall design: Biopsies from 20 ES patients using paraffin-embedded tissues and normal human mesenchymal stromal cells as controls.

尤因肉瘤（Ewing Sarcoma, ES）的分子致病机制目前仍未完全明确。本研究采用微阵列分析技术，对比了20例未接受治疗的原发性尤因肉瘤患者活检组织与正常人间充质基质细胞（mesenchymal stromal cells, MSCs）的全局微小RNA（microRNA, miRNA）表达谱，并借助miRTarBase数据库筛选差异表达miRNA的预测靶基因。微阵列分析结果显示，尤因肉瘤活检组织与正常MSCs的miRNA表达模式存在显著差异：在本次分析的954个miRNA中，有58个在尤因肉瘤样本与正常MSCs间呈现显著差异表达。此外，本研究对筛选出的3个miRNA开展实时定量逆转录聚合酶链反应（qRT-PCR）验证，结果显示miR-181b、miR-1915及miR-1275的表达存在显著异常，验证了微阵列分析的结果。生物数据库分析显示，BCL-2是miR-21、miR-181a、miR-181b、miR-29a、miR-29b、miR-497、miR-195、miR-Let-7a及miR-34a的真实靶基因。本研究利用尤因肉瘤的石蜡包埋组织，筛选出多个潜在的差异表达miRNA及一个靶基因，有望成为尤因肉瘤致病过程中的新型关键生物标志物。实验设计概况：本研究以20例尤因肉瘤患者的石蜡包埋组织活检样本及正常人间充质基质细胞作为对照。