Diagnostic and Prognostic Implications of a Serum miRNA Panel in Oesophageal Squamous Cell Carcinoma

Background and Aim
Circulating microRNAs (miRNAs) are potential biomarkers for cancer detection; however, little is known about their prognostic impact on oesophageal squamous cell carcinoma (ESCC). The current study aims to uncover novel miRNAs for prognostic biomarkers in ESCC patients.
Patients and Methods
We initially screened the expression of 754 serum miRNAs using TaqMan Low Density Array in two pooled samples respectively from 28 ESCC and 28 normal controls. Markedly upregulated miRNAs in ESCC and some miRNAs reported to be differently expressed in ESCC tissue were then validated individually by RT-qPCR in another 83 patients and 83 controls arranged in two phases. The changes of the selected miRNAs during the esophagectomy and their prognostic value were examined.
Results
Seven serum miRNAs were found to be significantly higher in ESCC than in controls; namely, miR-25, miR-100, miR-193-3p, miR-194, miR-223, miR-337-5p and miR-483-5p (P<0.0001), and the area under the receiver-operating-characteristic (ROC) curve (AUC) for the seven-miRNA panel was 0.83 (95% CI 0.75–0.90). Most of these miRNAs declined markedly in postoperative samples versus preoperative samples (P<0.05). Moreover, high level of miR-25 was significantly correlated with shorter overall survival in patients (P = 0.027). Cox regression analysis identified lymph node metastasis, miR-25 and miR-100 as the independent risk factors for overall survival (hazard ratio (HR) 2.98 [1.36–6.55], P = 0.006; HR 3.84 [1.02–14.41], P = 0.029; HR 4.18 [1.21–14.50], P = 0.024, respectively).
Conclusion
The seven serum miRNAs could potentially serve as novel biomarkers for ESCC; moreover, specific miRNAs such as miR-25 and miR-100 can predict poor survival in ESCC.

研究背景与研究目的
循环微小RNA（miRNAs）是颇具潜力的癌症检测生物标志物，但目前关于其对食管鳞状细胞癌（ESCC）的预后影响仍知之甚少。本研究旨在探索可用于ESCC患者预后评估的新型miRNAs生物标志物。

患者与研究方法
本研究首先采用TaqMan低密度阵列，分别对来自28例ESCC患者与28例健康对照者的混合血清样本中754种血清miRNAs的表达水平进行筛选。随后，针对在ESCC中显著上调的miRNAs以及已有报道在ESCC组织中存在差异表达的部分miRNAs，本研究分两阶段，采用实时定量聚合酶链反应（RT-qPCR）在另外83例ESCC患者与83例健康对照者样本中进行逐一验证。同时检测了所选miRNAs在食管切除术围手术期的表达变化，并评估其预后价值。

研究结果
研究发现，相较于健康对照者，ESCC患者血清中7种miRNAs的表达水平显著升高，分别为miR-25、miR-100、miR-193-3p、miR-194、miR-223、miR-337-5p及miR-483-5p（P<0.0001）；该7-miRNA联合检测模型的受试者工作特征（ROC）曲线下面积（AUC）达0.83（95%置信区间CI：0.75–0.90）。多数上述miRNAs在术后血清样本中的表达水平较术前显著降低（P<0.05）。此外，miR-25高表达与ESCC患者更短的总生存期显著相关（P=0.027）。Cox回归分析显示，淋巴结转移、miR-25及miR-100是ESCC患者总生存期的独立危险因素（风险比HR分别为2.98[95%CI：1.36–6.55]，P=0.006；3.84[95%CI：1.02–14.41]，P=0.029；4.18[95%CI：1.21–14.50]，P=0.024）。

研究结论
上述7种血清miRNAs有望成为ESCC诊断的新型生物标志物；此外，miR-25与miR-100等特定miRNAs可有效预测ESCC患者的不良预后。