Background: Lung adenocarcinoma (LUAD) exhibits pronounced cellular and molecular heterogeneity that shapes tumor progression and therapeutic response. Although nucleotide metabolism is essential for sustaining tumor proliferation and coordinating immune interactions, its single-cell heterogeneity and clinical implications remain incompletely defined.Methods: We integrated a publicly available scRNA-seq dataset derived from independent LUAD patients to construct a comprehensive LUAD cellular atlas, identified malignant epithelial cells using inferCNV, and reconstructed differentiation trajectories via Monocle2. Cell–cell communication patterns under distinct nucleotide metabolic states were assessed using CellChat. A nucleotide metabolism-related signature (NMRS) was subsequently developed across TCGA-LUAD and multiple GEO cohorts using 101 combinations of machine learning algorithms. Its prognostic and immunological predictive value was systematically evaluated. The functional relevance of the key gene ENO1 was further verified through pan-cancer analyses and in vitro experiments.Results: We identified substantial nucleotide metabolic heterogeneity within malignant epithelial cells, closely linked to elevated proliferative activity, glycolytic activation, and increased CNV burden. Pseudotime analysis showed that epithelial cells gradually acquire enhanced immune-modulatory and complement-related functions along their differentiation continuum. High-metabolism epithelial cells exhibited stronger outgoing communication—particularly via MIF, CDH5, and MHC-II pathways—highlighting their potential role in shaping an immunosuppressive microenvironment. The NMRS built from metabolism-related genes provided robust prognostic stratification across multiple cohorts and surpassed conventional clinical parameters. Immune profiling revealed that high-NMRS tumors displayed increased T-cell dysfunction, stronger exclusion, higher TIDE scores, and lower IPS, suggesting poorer responses to immune checkpoint blockade. ENO1, markedly upregulated in high-NMRS tumors and functioning as a risk factor in several cancer types, was experimentally shown to promote invasion in LUAD cell lines.Conclusions: This study delineates the profound impact of nucleotide metabolic reprogramming on epithelial cell states, immune ecology, and malignant evolution in LUAD. The NMRS provides a robust predictor of prognosis and immunotherapy response across cohorts, while ENO1 emerges as a pivotal metabolic–immune mediator and promising therapeutic target.
背景：肺腺癌（LUAD）表现出显著的细胞与分子异质性，这些异质性影响肿瘤进展和治疗反应。尽管核苷酸代谢对维持肿瘤增殖和协调免疫相互作用至关重要，但其单细胞层面的异质性及临床意义尚未完全阐明。 方法：我们整合了来自独立LUAD患者的公开单细胞RNA测序数据集，构建了全面的LUAD细胞图谱；利用inferCNV识别恶性上皮细胞，并通过Monocle2重建分化轨迹。使用CellChat评估不同核苷酸代谢状态下的细胞间通讯模式。随后，基于101种机器学习算法组合，在TCGA-LUAD及多个GEO队列中开发了核苷酸代谢相关特征（NMRS），并系统评估其预后和免疫预测价值。通过泛癌分析和体外实验进一步验证了关键基因ENO1的功能相关性。 结果：我们在恶性上皮细胞内发现了显著的核苷酸代谢异质性，这种异质性与增殖活性升高、糖酵解激活及拷贝数变异负荷增加密切相关。拟时序分析显示，上皮细胞在分化过程中逐渐获得增强的免疫调节和补体相关功能。高代谢上皮细胞表现出更强的外向通讯能力——尤其是通过MIF、CDH5和MHC-II通路——凸显了其在塑造免疫抑制微环境中的潜在作用。基于代谢相关基因构建的NMRS在多个队列中均能提供稳健的预后分层，其预测效能优于传统临床参数。免疫特征分析显示，高NMRS肿瘤表现出更高的T细胞功能障碍、更强的免疫排斥、更高的TIDE评分及更低的免疫表型评分，提示其对免疫检查点阻断疗法的反应可能较差。实验证实，在高NMRS肿瘤中显著上调的ENO1在多种癌症中作为风险因子，能够促进LUAD细胞系的侵袭能力。 结论：本研究揭示了核苷酸代谢重编程对LUAD上皮细胞状态、免疫生态和恶性演化的深远影响。NMRS为跨队列的预后和免疫治疗反应提供了可靠的预测指标，而ENO1则成为关键的代谢-免疫调节因子和潜在的治疗靶点。
肿瘤(癌症)患者之家