Data_Sheet_3_Single-Cell Analysis Reveals Spatial Heterogeneity of Immune Cells in Lung Adenocarcinoma.PDF

The impacts of the tumor microenvironment (TME) on tumor evolvability remain unclear. A challenge for nearly all cancer types is spatial heterogeneity, providing substrates for the emergence and evolvability of drug resistance and leading to unfavorable prognosis. Understanding TME heterogeneity among different tumor sites would provide deeper insights into personalized therapy. We found 9,992 cell profiles of the TME in human lung adenocarcinoma (LUAD) samples at a single-cell resolution. By comparing different tumor sites, we discovered high TME heterogeneity. Single-sample gene set enrichment analysis (ssGSEA) was utilized to explore functional differences between cell subpopulations and between the core, middle and edge of tumors. We identified 8 main cell types and 27 cell subtypes of T cells, B cells, fibroblasts and myeloid cells. We revealed CD4+ naive T cells in the tumor core that express high levels of immune checkpoint molecules and have a higher activity of immune-exhaustion signaling. CD8+ T cell subpopulations in the tumor core correlate with the upregulated activity of transforming growth factor-β (TGF-β) and fibroblast growth factor receptor (FGFR) signaling and downregulated T cell activity. B cell subtypes in the tumor core downregulate cytokine production. In this study, we revealed that there was immunological heterogeneity in the TME of patients with LUAD that have different ratios of immune cells and stromal cells, different functions, and various degrees of activation of immune-related pathways in different tumor parts. Therefore, clarifying the spatial heterogeneity of the tumor in the immune microenvironment can help clinicians design personalized treatments.

肿瘤微环境（tumor microenvironment, TME）对肿瘤演化能力的影响迄今仍未明确。几乎所有癌症类型均面临空间异质性这一核心挑战，该特征为耐药性的产生与演化提供了增殖基础，并最终导致不良预后。解析不同肿瘤部位的TME异质性，将为肿瘤个性化治疗提供更为深入的理论依据。本研究获取了9992个单细胞分辨率下的人肺腺癌（lung adenocarcinoma, LUAD）样本的TME细胞谱。通过对比不同肿瘤部位，我们发现TME存在高度异质性。采用单样本基因集富集分析（single-sample gene set enrichment analysis, ssGSEA），我们探究了细胞亚群间以及肿瘤核心区、中间区与边缘区之间的功能差异。本研究共鉴定出T细胞、B细胞、成纤维细胞及髓系细胞共8种主要细胞类型与27种细胞亚型。研究发现，肿瘤核心区的CD4+初始T细胞高表达免疫检查点分子，且免疫耗竭信号通路活性更高；肿瘤核心区的CD8+ T细胞亚群与转化生长因子-β（transforming growth factor-β, TGF-β）及成纤维细胞生长因子受体（fibroblast growth factor receptor, FGFR）信号通路活性上调、T细胞整体活性下调相关；肿瘤核心区的B细胞亚型的细胞因子产生能力显著下调。本研究揭示，肺腺癌患者的TME存在显著免疫异质性：不同肿瘤部位的免疫细胞与基质细胞比例、功能特征以及免疫相关通路激活程度均存在明显差异。因此，明确肿瘤免疫微环境的空间异质性，可辅助临床医生制定更为精准的个性化治疗方案。