目的 泛素特异性蛋白酶48(Ubiquitin-Specific Protease 48,USP48)是泛素特异性蛋白酶(USP)家族的成员，在特定癌症类型中下调。然而，USP48在乳腺癌患者中的表达模式和临床病理意义尚不清楚。本研究目的是初步探讨USP48在乳腺癌中的表达情况。方法 挖掘 oncomine 数据库，提取 USP48 在乳腺癌与正常组织转录水平表达情况；采用实时定量 PCR、Western blot 检测10 例分子分型为 Luminal A型的乳腺癌及正常乳腺癌旁组织中USP48 mRNA及蛋白水平加以验证。结果 Oncomine 数据库预测USP48 mRNA在侵袭性乳腺癌中表达水平降低；新鲜乳腺癌标本中，USP48 mRNA和蛋白水平明显低于相对应的癌旁正常乳腺组织。结论 初步研究显示，USP48 mRNA和蛋白水平在乳腺癌中下调，USP48可能在乳腺癌中发挥抑癌基因发挥作用，为探索USP48在乳腺中的致病机制研究和生物学作用奠定初步研究基础。

Objective Ubiquitin specific protease 48 (USP48) , a member of the USP family, is downregulated in specific cancer types. However, the expression pattern and clinicopathological significance of USP48 in patients with breast cancer is still unclear. To investigate the express and position of USP48 in breast cancer. Methods: We analysed the mRNA expression of USP48 in breast cancer using Oncomine. And then，10 cases of breast cancer patients tissue samples (Luminal A) and matched normal tissues were collected and USP48 protein and mRNA expressions were detected by western blot and RT-PCR, respectively. Results: The ONCOMINE database showed decreased USP48 expression in breast cancer tissue compared to normal tissue. In 10 fresh breast cancer tissues examined, 10 of them exhibited lower levels of USP48 protein and mRNA in comparison with their corresponding normal tissue. Conclusion:The preliminary studies have shown that USP48 mRNA and protein levels are downregulated in breast cancer.，suggestinng that USP48 may play a role in tumor suppressor genes in breast cancer, and lay a preliminary research foundation for exploring the pathogenic mechanism and biological role of USP48 in breast cancer.