目的 泛素特异性蛋白酶53（ubiquitin-specific protease 53，USP53）在结直肠癌（colon adenocarcinoma，COAD）中的临床意义和潜在机制尚不清楚。本研究采用生物信息学结合体外细胞学实验，观察USP53对结直肠癌细胞的抗癌作用。 方法 分析来自TCGA-COAD和GEO数据库（GSE39582数据集）的USP53表达数据。通过KEGG、GO和GSEA富集分析，探讨USP53可能参与的生物过程和信号通路。通过免疫浸润分析、药物敏感性分析结合CLUE平台和分子对接技术，预测潜在可用于治疗的小分子化合物。通过10种机器学习算法和101种集成组合构建预后预测模型，通过体外实验验证USP53的生物功能。 结果 USP53在COAD中具有抗肿瘤作用，低表达与较差的预后相关（P<0.05）。免疫浸润分析显示USP53低表达组有更高的免疫浸润水平，以及更高的TIDE和功能障碍评分（P<0.01）。体外实验表明，USP53过表达抑制了肿瘤细胞的增殖和迁移（P<0.05），并抑制了上皮-间质转化（epithelial-mesenchymal transition，EMT）。 结论 USP53通过影响EMT、凋亡、细胞周期调控和肿瘤免疫逃逸等机制发挥抗肿瘤作用，可能成为COAD的新型预后标志物。

Objective To investigate the antitumor effect of ubiquitin-specific protease 53（USP53） in colon adenocarcinoma（COAD） cells using bioinformatics methods combined with in vitro cellular experiments，since the clinical significance and potential mechanisms of USP53 in COAD remains unclear. Methods The expression data of USP53 from TCGA-COAD and GEO database （GSE39582 cohort） were analyzed，and KEGG，GO，and GSEA enrichment analyses were used to explore the biological processes and signaling pathways in which USP53 might be involved. The immune infiltration analysis and drug sensitivity analysis，along with the CLUE platform and molecular docking techniques，were used to predict the potential small-molecule compounds for treatment. A prognostic prediction model was established using 10 machine learning algorithms and 101 ensemble combinations，and in vitro experiments were performed to validate the function of USP53. Results USP53 exhibited an antitumor effect in COAD，and the low expression of USP53 was associated with poor prognosis（P<0.05）. The immune infiltration analysis showed that the low USP53 expression group had a higher level of immune infiltration，as well as higher TIDE and dysfunction scores（P<0.01）. In vitro experiments showed that USP53 overexpression inhibited the proliferation and migration of tumor cells and inhibited epithelial-mesenchymal transition （EMT）（P<0.05）. Conclusion USP53 exerts an antitumor effect by influencing the mechanisms such as EMT，apoptosis，cell cycle regulation，and tumor immune escape，and it may become a novel prognostic marker for COAD.