血清外泌体来源的microRNA-221-3p在肝细胞癌中的表达及意义

目的探讨肝细胞癌(HCC)患者血清外泌体来源microRNA(miRNA)-221-3p的表达水平及分析其临床意义。方法选取2010年2月-2014年12月南京大学医学院附属南京鼓楼医院经手术治疗后诊断为HCC的66例患者作为HCC组,选取25例同期在本院接受健康检查的体检者作为对照组。通过外泌体提取试剂盒分离HCC组和对照组血清中的外泌体,采用蛋白免疫印迹检测外泌体标记蛋白分子,透射电镜鉴定血清外泌体形态;实时荧光定量PCR方法检测两组血清外泌体来源的miRNA-221-3p表达水平。计量资料两组间比较采用Mann-Whitney U检验,计数资料两组间比较采用χ^2检验。采用Kaplan-Meier方法及log-rank检验分析血清外泌体来源的miRNA-221-3p表达与预后关系,采用Cox比例风险回归模型分析预后影响因素。结果血清来源的外泌体是直径为40~100 nm囊泡体,表达HSP70、Alix及CD63。HCC组血清来源外泌体中miRNA-221-3p较对照组表达水平升高,差异具有统计学意义(U=354.00,P<0.001)。HCC患者血清外泌体miRNA-221-3p高表达与肿瘤大小(χ^2=6.016,P=0.014)、包膜侵犯(χ^2=7.580,P=0.006)和TNM分期(χ^2=6.340,P=0.012)有关。此外,血清外泌体来源的miRNA-221-3p表达水平较高的HCC患者总体生存率较低,差异具有统计学意义(χ^2=17.105,P<0.001)。多因素分析结果表明血清外泌体来源的miRNA-221-3p表达水平(风险比=2.434,95%可信区间:1.178~5.027,P=0.016)及肿瘤分期(风险比=2.653,95%可信区间:1.222~5.760,P=0.014)是影响HCC患者预后的独立危险因素。结论HCC患者血清外泌体来源的miRNA-221-3p表达水平明显升高,对HCC诊断及预后判断具有参考价值。

Expression and clinical significance of serum exosomal microRNA-221-3p in hepatocellular carcinoma

Objective To investigate the expression and clinical significance of serum exosomal microRNA(miRNA)-221-3p in hepatocellular carcinoma(HCC).Methods A total of 66 patients who underwent surgery in Nanjing Drum Tower Hospital,Nanjing University Medical School,from February 2010 to December 2014 and were diagnosed with HCC were enrolled as HCC group,and 25 individuals who underwent physical examination in our hospital during the same period of time were enrolled as control group.The exosome extraction kit was used to isolate the exosomes in serum;Western blotting was used to measure the expression of exosome markers;a transmission electron microscope was used to observe the morphology of serum exosomes;quantitative real-time PCR was used to measure the expression of serum exosomal miRNA-221-3p.The Mann-Whitney U test was used for comparison of continuous data between two groups,and the chi-square test was used for comparison of categorical data between two groups.The Kaplan-Meier method and the log-rank test were used to analyze the association of the expression of serum exosomal miRNA-221-3p with prognosis,and the Cox proportional hazards regression model was used to analyze the influencing factors for prognosis.Results Serum exosomes were small membranous vesicles with a diameter of about 40-100 nm,and HSP70,Alix,and CD63 were expressed in the exosomes.The HCC group had significantly higher expression of serum exosomal miRNA-221-3p than the control group(U=354.00,P<0.001).In the patients with HCC,the high expression of serum exosomal miRNA-221-3p was associated with tumor size(χ^2=6.016,P=0.014),capsular invasion(χ^2=7.580,P=0.006),and TNM stage(χ^2=6.340,P=0.012).In addition,the HCC patients with high expression of serum exosomal miRNA-221-3p had a significantly lower overall survival rate than those with low expression(χ^2=17.105,P<0.001).The multivariate analysis showed that the expression of serum exosomal miRNA-221-3p(hazard ratioHR]=2.434,95%confidence intervalCI]:1.178-5.027,P=0.016)and tumor stage(HR=2.653,95%CI:1.222-5.760,P=0.014)were independent risk factors for the prognosis of patients with HCC.Conclusion There is a significant increase in the expression of serum exosomal miRNA-221-3p in HCC patients,which provides a reference for the diagnosis and prognostic evaluation of HCC.