MicroRNAs (miRNAs) are key regulators that play important biological roles in carcinogenesis and are promising biomarkers for cancer diagnosis and therapy. hsa-miR-375-3p (miR-375) has been suggested to serve as a tumor suppressor or oncogene in various tumor types; however, its specific expression and potential regulatory role in malignant breast cancer remain unclear. In this study, the results from noncoding RNA microarray analysis indicated that the miR-375 expression level is significantly decreased in malignant basal-like breast cancer compared with luminal-like breast cancer. A total of 1895 co-downregulated and 1645 co-upregulated genes were identified in miR-375 mimic-transfected basal-like breast cancer cell lines. Predicted miR-375 targets were obtained from the online databases TargetScan and DIANA-microT-CDS. Combined KEGG enrichment analysis for coregulated genes and predicted miR-375 targets provided information and revealed differences in potential dynamic signaling pathways regulated by miR-375 and also indicated specific regulatory pathways, such as RNA transport and processing, in basal-like breast cancer. Additionally, gene expression microarray analysis accompanied by UALCAN analysis was performed to screen upregulated genes in the basal-like subtype. Four potential key genes, including LDHB, CPNE8, QKI, and EIF5A2, were identified as candidate target genes of miR-375. Therefore, the present study demonstrated that miR-375 may be a potential key regulator and provide a promising direction for diagnostic and therapeutic developments for malignant breast cancer.

中文翻译：

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综合的生物信息学分析确定miR-375是恶性乳腺癌的候选关键调控因子。

微小RNA（miRNA）是关键调节剂，在致癌作用中起着重要的生物学作用，并且是癌症诊断和治疗的有前途的生物标记。已建议将hsa-miR-375-3p（miR-375）用作各种肿瘤类型的抑癌剂或癌基因。然而，其在恶性乳腺癌中的特异性表达和潜在调控作用仍不清楚。在这项研究中，非编码RNA微阵列分析的结果表明，与管腔样乳腺癌相比，miR-375表达水平在恶性基底样乳腺癌中显着降低。在miR-375模拟转染的基底样乳腺癌细胞系中共鉴定到1895个共同下调的基因和1645个共同上调的基因。预测的miR-375靶标是从在线数据库TargetScan和DIANA-microT-CDS获得的。结合KEGG富集分析的基因和预测的miR-375靶标提供了信息，并揭示了miR-375调控的潜在动态信号传导途径的差异，还表明了基底样乳腺癌中特定的调控途径，例如RNA转运和加工。此外，进行了基因表达微阵列分析和UALCAN分析，以筛选基底样亚型中上调的基因。四个潜在的关键基因，包括 进行基因表达微阵列分析和UALCAN分析，以筛选基底样亚型中上调的基因。四个潜在的关键基因，包括 进行基因表达微阵列分析和UALCAN分析，以筛选基底样亚型中上调的基因。四个潜在的关键基因，包括LDHB，CPNE8，QKI和EIF5A2被确定为miR-375的候选靶基因。因此，本研究证明miR-375可能是潜在的关键调节剂，并为恶性乳腺癌的诊断和治疗发展提供了有希望的方向。