目的：探究染色体结构维持蛋白 4（SMC4）在乳腺癌中的表达及其评估患者预后的价值。方法： 利用 TIMER、 GEPIA等数据库数据分析SMC4在乳腺癌组织中的表达及其与患者临床病理特征间的相关性；用免疫组化法检测SMC4蛋白在 乳腺癌组织中的表达，并探讨其与乳腺癌临床病理特征之间的关系；通过Cox回归模型、Kaplan-Meier生存曲线、GEPIA数据库数 据评估SMC4表达与乳腺癌患者生存期之间的关系。结果：生物信息学分析结果显示，SMC4 mRNA在乳腺癌组织中的表达水 平明显高于癌旁组织（P < 0.01），并与临床分期、淋巴结转移及化疗耐药密切相关（均P < 0.05）。免疫组化法检测结果显示， 在乳腺癌组织中SMC4的阳性及强阳性表达率均显著高于癌旁组织（均P < 0.05）；SMC4蛋白的高表达与乳腺癌患者年龄、临床 分期和淋巴结转移密切相关（均 P < 0.05）。SMC4 蛋白低表达组的患者累积生存率显著高于 SMC4 蛋白高表达组，尤其是在 HER2阳性乳腺癌患者中（均P < 0.05），且SMC4是乳腺癌患者预后的独立危险因素。结论：SMC4在乳腺癌组织中呈高表达， SMC4高表达与乳腺癌患者的淋巴结转移、临床分期及预后密切相关，可作为乳腺癌诊断与预后评判的潜在标志物。

Objective: To investigate the expression of structural maintenance of chromosome 4 (SMC4) in breast cancer and its prognostic value. Methods: The expression of SMC4 gene in breast cancer tissues and its correlation with the clinicopathological characteristics of patients were analyzed using the TIMER, GEPIA, UALCAN and GEO databases. The expression of SMC4 protein in breast cancer and adjacent normal tissues was detected using immunohistochemical (IHC) staining. Correlations between SMC4 expression and clinicopathological features of breast cancer were evaluated. The relationship between SMC4 expression and survival of patients with breast cancer was evaluated by Kaplan-Meier, GEPIA database, Cox proportional hazards regression model. Results: Bioinformatics analysis showed that the mRNA level of SMC4 in breast cancer tissues was significantly higher than that in normal adjacent tissues (P < 0.01), and was closely related to clinical stage, lymph node metastasis and chemotherapy resistance (all P < 0.05). IHC staining showed that the positive and strong positive rates of SMC4 in breast cancer tissues were significantly higher than those in normal adjacent tissues (all P < 0.05). The high protein expression of SMC4 was closely related to the age, clinical stage and lymph node metastasis of breast cancer patients (all P < 0.05). The cumulative survival rate of patients in SMC4 low expression group was significantly higher than that in the SMC4 high expression group, especially in patients with HER2+ breast cancer (P < 0.05). Additionally, SMC4 is an independent risk factor for prognosis in patients with breast cancer. Conclusion: SMC4 is highly expressed in breast cancer tissues. High SMC4 expression is closely related to lymph node metastasis, clinical stage, and prognosis of patients with breast cancer, making it a potential marker for the diagnosis and prognosis of breast cancer.

国家自然科学基金（No. 82160552）