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.

研究背景：铜死亡（Cuproptosis）是一种受蛋白质脂酰化调控的新型细胞死亡形式，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（GCSH）对子宫内膜癌（EC）的预后、肿瘤免疫微环境及治疗响应的影响仍有待进一步探究。
研究方法：本研究通过多个公共数据库分析了子宫内膜癌与正常组织中GCSH的差异表达水平。此外，前瞻性收集了17例子宫内膜癌患者的癌组织及癌旁组织，采用免疫组化分析进一步验证GCSH的表达差异。评估了GCSH与子宫内膜癌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。随后，利用基因集变异分析（GSVA）探索了GCSH在子宫内膜癌中潜在的生物学功能。通过相关分析评估了GCSH对肿瘤微环境（TME）的影响。最后，探究了GCSH对子宫内膜癌患者免疫治疗与化疗药物响应的作用。
研究结果：子宫内膜癌组织中GCSH的表达水平显著上调。GCSH高表达与子宫内膜癌患者的不良预后显著相关。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高表达与非炎性肿瘤微环境相关，可导致免疫细胞浸润水平降低。最后观察到，GCSH高表达的子宫内膜癌患者对免疫治疗及化疗药物均不敏感。
研究结论：本研究阐明了GCSH在子宫内膜癌肿瘤微环境、治疗响应及临床预后中的作用，为子宫内膜癌的临床治疗应用提供了全新的理论参考。