血清外泌体miR-221和miR-378水平检测在胃癌诊断中的应用研究

Application Study of Serum Exosome miR-221 and miR-378 Detection in the Diagnosis of Gastric Cancer

目的研究血清外泌体中miR-221和miR-378水平及其联合检测对诊断胃癌的价值。方法选取延安市人民医院收治的胃癌患者92例为试验组,选取同期诊断为胃息肉的患者68例和同期健康体检者50例为对照组,空腹采集静脉血提取血清外泌体用Western Blot和Nanosight法鉴定,用实时荧光定量PCR检测血清外泌体miR-221和miR-378水平,用ROC曲线分析miR-221和miR-378联合检测对胃癌的诊断效能。结果血清外泌体标本经Western Blot蛋白标志物检测鉴定和Nanosight颗粒浓度检测鉴定,结果显示所提取的标本中确实含有外泌体。用实时荧光定量PCR对标本进行定量检测结果显示,血清外泌体中miR-221和miR-378水平胃癌组高于胃息肉组,胃息肉组又高于健康对照组,差异均有统计学意义(F=7.112~10.986,均P<0.01)。ROC曲线分析显示,miR-221和miR-378联合检测对胃癌诊断的特异度、灵敏度、诊断符合率以及阴性预测值都明显高于单独检测,差异均有统计学意义(P<0.05),说明这两种miRNA联合检测对胃癌的诊断效能高于单独检测。结论血清外泌体miR-221和miR-378水平联合检测对诊断胃癌有潜在的应用价值。

Objective To study the levels of miR-221 and miR-378 in serum exosomes and their combined detection value in the diagnosis of gastric cancer.Methods Selected 92 gastric cancer cases from Yan’an People’s Hospital as experimental group,selected 68 gastric polyps cases in the same period,and selected 50 healthy persons doing physical examinations as control group.Fasting venous blood was collected to extract and identify exosomes using Western Blot and Nanosight method.Real-time quantitative PCR was used to detect levels of miR-221 and miR-378 in the serum exosomes.ROC curve analysis was used to analyze diagnostic efficiency of joint detection of miR-221 and miR-378 for gastric cancer.Results Western Blot protein marker identification and Nanosight particle concentration detection results of serum exosome samples showed that the extracted samples did contain exosomes.Real-time quantitative PCR detection showed that the expression levels of miR-221 and miR-378 in serum exosomes were higher in gastric cancer group than those in gastric polyp control group,which were higher than those in healthy control group,and the differences were statistically significant(F=7.112~10.986,all P<0.01).ROC curve analysis showed that the specificity,sensitivity,diagnostic coincidence rate and negative predictive value of the combined detection of miR-221 and miR-378 were significantly higher than those of the single detection,and the differences were statistically significant(P<0.05).The results indicated that the combined detection was more effective than single detection.Conclusion The combined detection of serum exosome miR-221 and miR-378 levels has potential application value in the diagnosis of gastric cancer.