探讨微小RNA-21（miR-21）和miR-17-5p在乳腺癌患者血浆外泌体中的表达水平及其诊断价值。

选取2017年6月至2018年3月于成都市第七人民医院就诊的86例乳腺癌患者为乳腺癌组，选取同期体检健康女性45例为对照组。采用实时定量聚合酶链反应（qRT-PCR）检测miR-21、miR-17-5p在两组血浆外泌体中的表达水平。根据qRT-PCR检测结果将乳腺癌患者分为miR-17-5p高表达组及低表达组，miR-21高表达组及低表达组，比较分析其与乳腺癌患者临床病理参数的关系。采用受试者工作特征曲线（ROC）分析血浆外泌体miR-21、miR-17-5p对乳腺癌的诊断价值。

乳腺癌组患者血浆外泌体miR-17-5p表达水平显著低于对照组（P<0.05），而miR-21表达水平显著高于对照组（P<0.05）；miR-17-5p单独检测时曲线下面积（AUC）为0.677，敏感度为58.14%，特异度为75.56%，截断值为0.72；miR-21单独检测时AUC为0.694，敏感度为59.30%，特异度为77.78%，截断值为1.68；联合检测时敏感度为96.51%，特异度为95.56%，准确性为96.18%；联合检测诊断乳腺癌的敏感度、特异度及准确性均显著高于单项检测（P<0.05）。血浆外泌体miR-17-5p、miR-21表达水平均与TNM分期、分化程度、淋巴结转移、cerbB-2及Ki-67有关（P<0.05）。

血浆外泌体低表达的miR-17-5p与高表达的miR-21均可作为诊断乳腺癌的潜在生物学标志物。

To investigate the expression of micro RNA-21 (miR-21) and micro RNA-17-5p (miR-17-5p) in the plasma of patients with breast cancer and their diagnostic values.

Eighty-six patients with breast cancer diagnosed in Chengdu Seventh People’s Hospital from June 2017 to March 2018 were selected as the breast cancer group, and 45 healthy women were selected as the control group. Real-time quantitative polymerase chain reaction (qRT-PCR) was used to detect the expression of miR-21 and miR-17-5p in plasma exosomes of two groups. According to the results of qRT-PCR, breast cancer patients were divided into miR-17-5p high-expression group and miR-17-5p low-expression group, miR-21 high-expression group and miR-21 low-expression group, and the relationship between them with clinicopathological parameters of breast cancer patients was analyzed. The diagnostic values of plasma exosomes miR-21 and miR-17-5p in breast cancer were analyzed by receiver operating characteristic curve (ROC).

The expression of plasma exosome miR-17-5p in breast cancer group was significantly lower than that in control group (P<0.05), and the expression of plasma exosomemiR-21 was significantly higher (P<0.05). The area under curve (AUC) of detection of miR-17-5p alone was 0.677, the sensitivity was 58.14%, the specificity was 75.56%, and the truncation value was 0.72; the AUC of detection of miR-21 alone was 0.694, the sensitivity was 59.30%, the specificity was 77.78%, and the truncation value was 1.68; the sensitivity, specificity and accuracy of combined detection were 96.51%, 95.56% and 96.18% respectively; the sensitivity, specificity and accuracy of combined detection of breast cancer were significantly higher than those of single detection (P<0.05). The expression levels ofmiR-17-5p and miR-21in plasma exosomes were correlated with TNM stage, differentiation degree, lymph nodemetastasis, cerbB-2 and Ki-67 (P<0.05).

Low expression of miR-17-5p and high expression of miR-21 in plasma exosome can be used as potential biomarkers for the diagnosis of breast cancer.