Expression of miRNAs among studied groups.

Background
The early detection of breast cancer (BC) is receiving global attention, creating an urgent need for more sensitive and comprehensive strategies for preventive intervention, therapy assessment, and prognosis prediction. Aberrant expression of miRNAs has been observed in various malignancies and may be potential targets for therapy. Our study aims to examine the expression profiles of miR-375, miR-574-3p, and miR-122 in the sera of Egyptian women with BC, benign breast lesions, and a control group. We hope to determine if these miRNAs can serve as minimally invasive biomarkers for BC.
Methods
This is a case-control study in which 77 patients with newly diagnosed BC, 20 patients with benign breast tumors, and 30 normal healthy subjects as controls were recruited from the outpatient clinic of the National Cancer Institute. The assessment of miRNAs was conducted using RT-PCR (Applied Biosystems).
Results
The expression level of miRNA-122 was significantly upregulated in the BC group, while the expression levels of miRNA-574 and miRNA-375 showed significant downregulation in BC patients. Serum miR-122 and miRNA-375 were able to distinguish breast cancer from the benign and control groups in ROC curve analysis, with AUCs of 0.786 and 0.796, respectively. Our results also showed that serum miR-122 and miR-574 are significant predictor variables in the multivariate analysis, after adjusting for age.
Conclusions
Our findings suggest that miR-122 may act as an onco-microRNA, while miR-574 and miR-375 may have a main tumour suppressor role. The studied miRNAs may serve as minimally invasive biomarkers for cases of breast cancer and as promising potential therapeutic targets for breast cancer.

研究背景
乳腺癌（breast cancer, BC）的早期检测正受到全球广泛关注，由此亟需开发更为灵敏且全面的策略，用于预防性干预、疗效评估与预后预测。微小核糖核酸（microRNA, miRNA）的异常表达已在多种恶性肿瘤中被检出，其或可成为肿瘤治疗的潜在靶点。本研究旨在检测埃及乳腺癌患者、乳腺良性病变患者及健康对照组女性血清中miR-375、miR-574-3p与miR-122的表达谱，以期明确上述miRNA能否作为乳腺癌的微创生物标志物。
研究方法
本研究为病例对照研究，从国家癌症研究所门诊招募了77例新诊断乳腺癌患者、20例乳腺良性肿瘤患者及30名健康受试者作为对照。采用逆转录聚合酶链式反应（Reverse Transcription-Polymerase Chain Reaction, RT-PCR，应用生物系统公司（Applied Biosystems））开展miRNA表达水平检测。
研究结果
乳腺癌组中miR-122的表达水平显著上调，而乳腺癌患者体内miR-574与miR-375的表达水平则显著下调。经受试者工作特征（Receiver Operating Characteristic, ROC）曲线分析显示，血清miR-122与miR-375可有效区分乳腺癌患者与良性病变患者及健康对照组，二者的曲线下面积（Area Under Curve, AUC）分别为0.786与0.796。在校正年龄因素后，多变量分析结果表明，血清miR-122与miR-574为显著的预测变量。
研究结论
本研究结果提示，miR-122或可作为致癌性微小核糖核酸（onco-microRNA）发挥作用，而miR-574与miR-375则主要具备肿瘤抑制功能。本次研究涉及的miRNA或可作为乳腺癌的微创生物标志物，同时也有望成为乳腺癌治疗的潜在靶点。