The study aimed to compare the Steroid 5 alpha-reductase 3 (SRD5A3) expression levels in breast cancer (BC) and normal tissues, to investigate the prognostic value of SRD5A3 mRNA expression in BC patients and to identify the SRD5A3-related signaling pathways using bioinformatics approaches. We evaluated the expression levels of SRD5A3 and survival data in BC patients using different bioinformatic databases. Further, Cox regression analysis was conducted to predict the independent prognostic factors for BC. Moreover, the association of SRD5A3 with clinicopathological factors was measured through LinkedOmics database. And the potential role of SRD5A3 was determined by Gene Ontology and KEGG pathway enrichment analysis. Finally, protein network of SRD5A3 was constructed and genetic alterations were analyzed. Bioinformatic data indicated that both mRNA and protein expression levels of SRD5A3 were higher in BC group than those in the normal group (P < 0.05). Besides, BC patients with higher SRD5A3 mRNA expression levels had a lower overall survival (all P < 0.05). Cox regression analysis further demonstrated the independent prognostic value of SRD5A3 in BC (P = 0.015). SRD5A3 mRNA expression was significantly associated with N stage (P < 0.001), age (P < 0.05), and histologic subtype (P < 0.001) but had no significant relationship with other clinical characteristics (all P > 0.05). Moreover, the functional enrichment analysis revealed that the SRD5A3 was involved in metabolism-related pathways (all P < 0.05). SRD5A3 was highly expressed in BC tissues and high SRD5A3 expression was related to poorer prognosis. SRD5A3 serves as an oncogene and might function as a potential biomarker for prognosis and a therapeutic target for BC.

中文翻译：

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SRD5A3的过表达及其在乳腺癌中的预后意义

本研究旨在比较乳腺癌 (BC) 和正常组织中类固醇 5 α-还原酶 3 (SRD5A3) 的表达水平，探讨 SRD5A3 mRNA 表达在 BC 患者中的预后价值，并利用生物信息学确定 SRD5A3 相关的信号通路方法。我们使用不同的生物信息学数据库评估了 BC 患者中 SRD5A3 的表达水平和生存数据。此外，进行 Cox 回归分析以预测 BC 的独立预后因素。此外，通过 LinkedOmics 数据库测量了 SRD5A3 与临床病理因素的关联。并且通过基因本体和KEGG通路富集分析确定了SRD5A3的潜在作用。最后，构建了SRD5A3的蛋白质网络并分析了遗传改变。生物信息学数据显示，BC组SRD5A3 mRNA和蛋白表达水平均高于正常组（P < 0.05）。此外，SRD5A3 mRNA表达水平较高的BC患者总生存期较低（均P < 0.05）。Cox 回归分析进一步证明了 SRD5A3 在 BC 中的独立预后价值（P = 0.015）。SRD5A3 mRNA表达与N分期（P < 0.001）、年龄（P < 0.05）和组织学亚型（P < 0.001）显着相关，但与其他临床特征无显着关系（均P > 0.05）。此外，功能富集分析显示SRD5A3参与代谢相关途径（均P <0.05）。SRD5A3 在 BC 组织中高表达，高 SRD5A3 表达与较差的预后有关。