靶向肿瘤微环境越来越被认为是治疗晚期肺腺癌（LUAD）的有效方法。然而，很少有研究探讨免疫疗法对LUAD的有效性。在这里，提出了一种新的预测免疫疗法有效性的方法，该方法结合了单细胞和批量测序，以表征LUAD的免疫微环境和代谢特征。使用TCGA批量数据集将免疫亚型分成了两种：C1具有“冷”肿瘤特征，而C2具有“热”肿瘤特征，并且具有不同的预后。基于这两种免疫亚型的Scissor算法将GSE131907单个细胞数据集分成了两组上皮细胞，标记为Scissor_C1和Scissor_C2。富集表明，Scissor_C1的特征是缺氧，缺氧微环境是诱导肿瘤侵袭、转移和免疫治疗不应答的潜在因素。此外，进行单细胞分析以研究缺氧微环境在LUAD中诱导侵袭、转移和免疫治疗不应答的分子机制。值得注意的是，Scissor_C1细胞与T细胞和癌相关成纤维细胞（CAF）显著相互作用，并表现出上皮间质转化和免疫抑制特征。CellChat分析显示，Scissor_C1中的缺氧微环境上调了TGFβ信号通路，并诱导出ANGPTL4和SEMA3C分泌。与ANGPTL4的内皮细胞相互作用可增加血管通透性，在血管内皮细胞间实现远处转移。此外，肿瘤相关巨噬细胞（TAM）与Scissor_C1通过EREG/EFGR通路相互作用，在LUAD患者中诱导酪氨酸激酶抑制剂耐药性。此后，确定了一组CAF细胞，其特征与Scissor_C1相同，在肿瘤微环境中发挥免疫抑制功能。此外，探讨了Scissor_C1基因网络中的关键基因（EPHB2和COL1A1），并使用免疫组织化学验证了它们的表达。最后，确定了细胞之间代谢失调的交互作用，其中TAM通过SLC38A2转运葡萄糖胺，而Scissor_C1则通过摄取来诱导LUAD细胞对葡萄糖胺的依赖。总体来说，单细胞测序阐明了肿瘤微环境如何通过分子机制和生物过程影响免疫疗法的有效性，而批量测序则基于临床信息解释了免疫疗法的有效性。版权所有©2023 Li，Zhou和Zheng。

Targeting the tumor microenvironment is increasingly recognized as an effective treatment of advanced lung adenocarcinoma (LUAD). However, few studies have addressed the efficacy of immunotherapy for LUAD. Here, a novel method for predicting immunotherapy efficacy has been proposed, which combines single-cell and bulk sequencing to characterize the immune microenvironment and metabolic profile of LUAD. TCGA bulk dataset was used to cluster two immune subtypes: C1 with "cold" tumor characteristics and C2 with "hot" tumor characteristics, with different prognosis. The Scissor algorithm, which is based on these two immune subtypes, identified GSE131907 single cell dataset into two groups of epithelial cells, labeled as Scissor_C1 and Scissor_C2. The enrichment revealed that Scissor_C1 was characterized by hypoxia, and a hypoxic microenvironment is a potential inducing factor for tumor invasion, metastasis, and immune therapy non-response. Furthermore, single cell analysis was performed to investigate the molecular mechanism of hypoxic microenvironment-induced invasion, metastasis, and immune therapy non-response in LUAD. Notably, Scissor_C1 cells significantly interacted with T cells and cancer-associated fibroblasts (CAF), and exhibited epithelial-mesenchymal transition and immunosuppressive features. CellChat analysis revealed that a hypoxic microenvironment in Scissor_C1elevated TGFβ signaling and induced ANGPTL4 and SEMA3C secretion. Interaction with endothelial cells with ANGPTL4, which increases vascular permeability and achieves distant metastasis across the vascular endothelium. Additionally, interaction of tumor-associated macrophages (TAM) and Scissor_C1 via the EREG/EFGR pathway induces tyrosine kinase inhibitor drug-resistance in patients with LAUD. Thereafter, a subgroup of CAF cells that exhibited same features as those of Scissor_C1 that exert immunosuppressive functions in the tumor microenvironment were identified. Moreover, the key genes (EPHB2 and COL1A1) in the Scissor_C1 gene network were explored and their expressions were verified using immunohistochemistry. Finally, the metabolism dysfunction in cells crosstalk was determined, which is characterized by glutamine secretion by TAM and uptake by Scissor_C1 via SLC38A2 transporter, which may induce glutamine addiction in LUAD cells. Overall, single-cell sequencing clarifies how the tumor microenvironment affects immunotherapy efficacy via molecular mechanisms and biological processes, whereas bulk sequencing explains immunotherapy efficacy based on clinical information.Copyright © 2023 Li, Zhou and Zheng.