Background The homeobox gene family, encoding a specific nuclear protein, is essential for embryonic development, differentiation, and homeostasis. The role of the HOXB3 protein varies in different tumors. This study aims to explore the role of the HOXB3 gene in breast cancer. Method Differentially expressed genes were screened by analyzing metastatic breast cancer gene chip data from TCGA and GEO databases. The function of the selected HOXB3 gene was also analyzed in different databases and through molecular biology methods, such as qRT-PCR, western blot and IF to verify bioinformatics findings. Results Both bioinformatics analyses and western blot showed that HOXB3 was lost in breast cancer compared to normal breast tissue. Survival analysis also showed that lower expression of HOXB3 was associated with poor prognosis. Bioinformatics analyses further showed that HOXB3 was positively correlated with hormone receptors. Metascape for GO analysis of GEO data provided possible mechanisms that HOXB3 could positively regulate cell adhesion, inhibit cell proliferation and activate immune response in breast cancer; moreover, GSEA included several cancer-associated pathways. Conclusion In summary, HOXB3 expression was decreased in breast cancer, and it was associated with poor prognosis. It might become a new biomarker to predict prognosis of breast cancer.

中文翻译：

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HOXB3 的缺失与激素受体阴性乳腺癌的发展相关

背景编码特定核蛋白的同源框基因家族对胚胎发育、分化和体内平衡至关重要。HOXB3蛋白的作用在不同的肿瘤中有所不同。本研究旨在探讨HOXB3基因在乳腺癌中的作用。方法通过分析TCGA和GEO数据库的转移性乳腺癌基因芯片数据，筛选差异表达基因。选择的 HOXB3 基因的功能也在不同的数据库中进行了分析，并通过分子生物学方法，如 qRT-PCR、蛋白质印迹和 IF 来验证生物信息学的发现。结果 生物信息学分析和蛋白质印迹均显示，与正常乳腺组织相比，HOXB3 在乳腺癌中丢失。生存分析还表明，HOXB3 的低表达与预后不良有关。生物信息学分析进一步表明 HOXB3 与激素受体呈正相关。用于对 GEO 数据进行 GO 分析的 Metascape 提供了 HOXB3 在乳腺癌中可以正向调节细胞粘附、抑制细胞增殖和激活免疫反应的可能机制；此外，GSEA 包括几个癌症相关的途径。结论综上所述，HOXB3在乳腺癌中的表达降低，与预后不良有关。它可能成为预测乳腺癌预后的新生物标志物。GSEA 包括几个与癌症相关的途径。结论综上所述，HOXB3在乳腺癌中的表达降低，与预后不良有关。它可能成为预测乳腺癌预后的新生物标志物。GSEA 包括几个与癌症相关的途径。结论综上所述，HOXB3在乳腺癌中的表达降低，与预后不良有关。它可能成为预测乳腺癌预后的新生物标志物。