Abstract

Background

Breast cancer, a genetically intricate disease with diverse subtypes, exhibits heightened incidence globally. In this study, we aimed to investigate blood-based microRNAs (miRNAs) as potential biomarkers for breast cancer. The primary objectives were to explore the role of miRNAs in cancer-related processes, assess their differential expression between breast cancer patients and healthy individuals, and contribute to a deeper understanding of the molecular underpinnings of breast cancer.

Methods

MiRNA extraction was performed on 40 breast cancer patients and adjacent normal tissues using a commercial RNA isolation kit. Total RNA quantification and quality assessment were conducted with advanced technologies. MiRNA profiling involved reverse transcription, labeling, and hybridization on Agilent human miRNA arrays (V2). Bioinformatics analysis utilized the DIANA system for target gene prediction and the DIANA-mirPath tool for pathway enrichment analysis. Selected miRNAs underwent validation through quantitative real-time PCR.

Results

Principal component analysis revealed overlapping miRNA expression patterns in primary and malignant breast tumors, underscoring the genetic complexity involved. Statistical analysis identified 54 downregulated miRNAs in malignant tumors and 38 in primary tumors compared to controls. Bioinformatics analysis implicated several pathways, including Wnt, TGF-b, ErbB, and MAPK signaling. Validation through qRT-PCR confirmed altered expression of hsa-miR-130a, hsa-miR-21, hsa-miR-223, and hsa-let-7c key miRNAs, highlighting their significance in breast cancer. The results from microarray were further validated by qPCR and the expression of which are downregulated in breast cancer was detected.

Conclusion

This study provides significant insights into distinct miRNA expression patterns in normal and malignant breast tissues. The overlapping miRNA profiles in primary and malignant tumors underscore the complexity of genetic regulation in breast cancer. The identification of deregulated miRNAs and affected pathways contributes to our understanding of breast cancer pathogenesis. The validated miRNAs hold potential as diagnostic and prognostic markers, offering avenues for further clinical exploration in breast cancer research.

中文翻译：

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基于血液的 microRNA 分析揭示了乳腺癌中复杂的分子动力学

摘要

背景

乳腺癌是一种具有多种亚型的复杂遗传疾病，在全球范围内发病率较高。在这项研究中，我们旨在研究血液中的 microRNA (miRNA) 作为乳腺癌的潜在生物标志物。主要目标是探索 miRNA 在癌症相关过程中的作用，评估其在乳腺癌患者和健康个体之间的差异表达，并有助于更深入地了解乳腺癌的分子基础。

方法

使用商业 RNA 分离试剂盒对 40 名乳腺癌患者和邻近正常组织进行 miRNA 提取。采用先进技术进行总RNA定量和质量评估。miRNA 分析涉及安捷伦人类 miRNA 阵列 (V2) 上的逆转录、标记和杂交。生物信息学分析利用 DIANA 系统进行靶基因预测，并利用 DIANA-mirPath 工具进行通路富集分析。选定的 miRNA 通过定量实时 PCR 进行验证。

结果

主成分分析揭示了原发性和恶性乳腺肿瘤中重叠的 miRNA 表达模式，强调了所涉及的遗传复杂性。统计分析发现，与对照相比，恶性肿瘤中有 54 个 miRNA 下调，原发性肿瘤中有 38 个 miRNA 下调。生物信息学分析涉及多种途径，包括 Wnt、TGF-b、ErbB 和 MAPK 信号传导。通过 qRT-PCR 验证证实了 hsa-miR-130a、hsa-miR-21、hsa-miR-223 和 hsa-let-7c 关键 miRNA 的表达发生改变，突出了它们在乳腺癌中的重要性。微阵列的结果通过qPCR进一步验证，并检测到其在乳腺癌中的表达下调。

结论

这项研究为正常和恶性乳腺组织中不同的 miRNA 表达模式提供了重要的见解。原发性肿瘤和恶性肿瘤中重叠的 miRNA 图谱强调了乳腺癌基因调控的复杂性。识别失调的 miRNA 和受影响的通路有助于我们了解乳腺癌发病机制。经过验证的 miRNA 具有作为诊断和预后标志物的潜力，为乳腺癌研究的进一步临床探索提供了途径。