结直肠癌患者血浆外泌体中miRNA-23b的表达及其临床意义

Expression and clinical significance of plasma exosomal miRNA-23b in colorectal cancer

目的探究结直肠癌患者血浆外泌体中miRNA-23b(miR-23b)表达水平与临床病理学特征及预后的关系。方法利用外泌体试剂盒提取65例结直肠癌患者和25例健康人血浆中的外泌体,分别使用透射电镜、Western Blot和纳米颗粒示踪法进行鉴定。采用RT-qPCR法检测外泌体中miR-23b的表达水平,并分析其与患者临床病理学特征及预后的关系。结果结直肠癌患者血浆外泌体中miR-23b的表达水平较正常健康人明显降低(P <0.001),其低表达与肿瘤分化程度、浸润深度、淋巴结转移、TNM分期、脉管浸润、神经侵犯显著相关(均P <0.05)。Kaplan-Meier生存分析显示,外泌体miR-23b低表达组患者的总生存期较高表达组明显缩短(P=0.003)。单因素和多因素分析表明,血浆外泌体中miR-23b低表达是影响结直肠癌患者总生存期的独立危险因素(HR=2.243,95%CI:1.093~5.024,P=0.029)。结论结直肠癌患者血浆外泌体中miR-23b的表达下调与多个不良临床病理学因素及较短的总生存期密切相关,具有成为评估结直肠癌预后生物标志物的潜力。

Objective To investigate the relationship between the expression level of miRNA-23 b(miR-23 b)in plasma exosomes and clinicopathological features and prognosis of patients with colorectal cancer(CRC).Methods Exosomes from plasma samples of 65 CRC patients and 25 healthy controls were extracted by using the ExoQuick Exosome Precipitation Solution,and were further validated by Transmission electron microscope,western blotting and Nanoparticle tracing assay,respectively. RT-qPCR was used to detect the expression level of miR-23 b in exosomes,and the relationship between miR-23 b and clinicopathological characteristics and prognosis of patients was further analyzed. Results The level of miR-23 b expression in plasma exosomes of CRC patients was significantly lower than that of healthy controls(P < 0.001),and its low expression was significantly associated with tumor differentiation,depth of invasion,lymph node metastasis,TNM stage,vascular infiltration,and nerve invasion(P < 0.05,respectively). Kaplan-Meier survival analysis showed that patients with low exosomal miR-23 b level had significantly shorter overall survival than those with higher level(P = 0.003). Further univariate and multivariate analyses indicated that low expression of miR-23 b in plasma exosomes was an independent factor for affecting overall survival of CRC patients(HR=2.243,95%CI:1.093 ~ 5.024,P = 0.029). Conclusions The down-regulation of miR-23 b expression in plasma exosomes of CRC patients was closely related to multiple unfavorable clinicopathological factors and shorter overall survival,which has the potential to be a biomarker for evaluating the prognosis of CRC.