Supplementary Material for: Comprehensive analysis of the relationship between cuproptosis-related gene GCSH and prognosis, tumor microenvironment infiltration, and therapy response in endometrial cancer

Background: Cuproptosis, a novel form of cell death regulated by protein lipoylation and implicated in mitochondrial metabolism. However, the impact of the cuproptosis-related gene γ-glutamylcysteine synthetase (GCSH) on endometrial cancer (EC) prognosis, tumor immune microenvironment, and therapeutic response remains to be further researched. Methods: The differential expression of GCSH between endometrial cancer and normal tissues was analyzed using multiple public databases. Additionally, cancer and adjacent tissues were prospectively collected from 17 EC patients, and immunohistochemical analysis was performed to further investigate GCSH expression differences. The relationship between GCSH and the prognosis and clinicopathological characteristics of EC patients was evaluated, and a nomogram was constructed to predict patient survival based on GCSH expression. Then, Gene set variation analysis (GSVA) was utilized to explore the potential biological functions of GCSH in EC. The impact of GCSH on the tumor microenvironment (TME) was estimated. Finally, the effect of GCSH on the response to immunotherapy and chemotherapeutic drugs in EC was investigated. Results: The expression of GCSH was significantly upregulated in EC. High GCSH expression was associated with poor prognosis in EC patients. Enrichment analysis showed that high GCSH was associated with immune suppression. Furthermore, high GCSH was found to be associated with a non-inflamed TME, leading to decreased infiltration levels of immune cells. Finally, it was observed that patients with high GCSH were insensitive to both immunotherapy and chemotherapeutic drugs. Conclusion: This study revealed the role of GCSH in TME, response to therapy, and clinical prognosis in EC, which provided novel insights for the therapeutic application in EC.

背景：铜死亡（Cuproptosis）是一种由蛋白质脂酰化修饰调控的新型细胞死亡形式，且与线粒体代谢密切相关。然而，铜死亡相关基因γ-谷氨酰半胱氨酸合成酶（γ-glutamylcysteine synthetase, GCSH）对子宫内膜癌（endometrial cancer, EC）的预后、肿瘤免疫微环境及治疗应答的影响仍有待深入研究。方法：本研究依托多组公共数据库，分析子宫内膜癌组织与正常组织中GCSH的表达差异；此外前瞻性收集17例EC患者的癌组织及癌旁组织，通过免疫组化分析进一步验证GCSH的表达差异。本研究评估了GCSH表达与EC患者预后及临床病理特征的关联，并基于GCSH表达构建了预测患者生存的列线图模型；随后采用基因集变异分析（Gene set variation analysis, GSVA）探究GCSH在EC中潜在的生物学功能，并评估其对肿瘤微环境（tumor microenvironment, TME）的影响；最后探究GCSH对EC患者免疫治疗与化疗药物应答的调控作用。结果：子宫内膜癌组织中GCSH的表达水平显著上调；GCSH高表达与EC患者不良预后显著相关。富集分析结果显示，GCSH高表达与免疫抑制状态密切相关；进一步研究发现，GCSH高表达与非炎性TME相关，可导致免疫细胞浸润水平降低；最后观察到，GCSH高表达的EC患者对免疫治疗及化疗药物均不敏感。结论：本研究阐明了GCSH在EC的肿瘤微环境、治疗应答及临床预后中的调控作用，为EC的临床治疗应用提供了全新的研究视角。