This study systematically reveals key cellular interaction mechanisms of lymph node metastasis in non-small cell lung cancer by integrating single-cell and spatial transcriptomic data, providing a novel experimental framework for investigating PD-L1 regulation and immune microenvironment-mediated immune escape.
Literature Overview
This article, 'Dissecting origin factors of lymph node metastasis in non-small cell lung cancer via multimodal omics,' published in the journal Nature Communications, systematically investigates the tumor microenvironment (TME) characteristics associated with lymph node (LN) metastasis in non-small cell lung cancer (NSCLC). By employing a multimodal omics strategy combining single-cell RNA sequencing (scRNA-seq), spatial transcriptomics (ST), and bulk RNA-seq, the study provides high-resolution analysis of paired metastatic lymph nodes (mLN) and primary tumor (mLN+ PT) tissues. It reveals the synergistic roles of tumor stemness, immunoglobulin expression, ferroptosis signaling, and immunosuppressive microenvironments in LN metastasis. Further analyses identify spatial organization patterns of key stromal and immune cell subsets, deepening our understanding of LN metastatic mechanisms.Background Knowledge
Lung cancer is the leading cause of cancer-related deaths worldwide, with non-small cell lung cancer (NSCLC) accounting for 80–90% of cases. Approximately 80–90% of lung cancer deaths are due to metastasis, and lymph node metastasis is a critical factor in NSCLC staging and prognosis, indicating disease progression and influencing treatment decisions. Although lymph nodes play a central role in tumor immune regulation and distant dissemination, the mechanisms underlying LN metastasis remain incompletely understood. Current research has largely focused on processes such as lymphangiogenesis, cancer cell migration, pre-metastatic niche formation, immune escape, and metabolic reprogramming, yet systematic, high-resolution dynamic analyses of the TME are still lacking.
Notably, the regulatory mechanisms of CD274 (i.e., PD-L1) expression in the metastatic microenvironment remain controversial. The traditional view holds that PD-L1 is primarily induced by immune cells or interferon signaling; however, recent studies have shown that tumor cells themselves can express immunoglobulins (Ig) and may participate in immune regulation. Nevertheless, the origin, functional role, and relationship between Ig expression and PD-L1 in NSCLC LN metastasis remain unclear. Furthermore, the mechanistic roles of tumor stemness and ferroptosis pathways in metastasis have not been systematically elucidated. Therefore, multimodal omics approaches are urgently needed to dissect the interaction network between malignant cells and the TME in LN metastasis, identifying key molecular programs driving LN colonization and immune escape, thus offering novel insights for targeted interventions.
Research Methods and Experiments
The research team collected tissue samples from 19 NSCLC patients, including mLN (n=22), matched mLN+ PT (n=20), and mLN+ N (n=4), performing scRNA-seq analysis and integrating public datasets (including mLN- PT, mLN- N, and normal LN samples) to enhance statistical power. Additionally, four paired mLN and mLN+ PT samples underwent spatial transcriptomics (ST) sequencing, with spatial clustering analysis performed using BayesSpace to reveal spatial organization features of the TME. Copy Number Variation (CNV) inference was used to distinguish malignant from non-malignant epithelial cells, and the CytoTRACE algorithm was applied to assess cellular stemness. GSEA was conducted to enrich stemness- and immune-related pathways, while NicheNet analysis predicted ligand-target interactions between cells. Experimental validation included immunohistochemistry and qPCR to confirm key gene expression patterns.Key Conclusions and Perspectives
Research Significance and Prospects
This study provides an unprecedented multimodal omics resource for understanding NSCLC lymph node metastasis. The identified FTH1-stemness axis and IGHG4-PD-L1 regulatory module offer a theoretical foundation for developing novel biomarkers and combination therapies. Notably, tumor-derived Ig may act as a new immune checkpoint regulator, challenging the traditional view of B cell-dominated humoral immunity and warranting validation in additional cancer types.
From a drug development perspective, FTH1, as a node intersecting ferroptosis and stemness, may be a promising target for overcoming drug resistance and metastasis. Meanwhile, the specific expression of CST1+ CAFs suggests their promoter could be leveraged to drive targeted therapies or CAR-T cell designs. Additionally, the spatially defined 'immune-excluded boundary' could serve as a predictive biomarker for treatment response, guiding patient stratification in immunotherapy.
Conclusion
This study systematically maps the cellular and molecular landscape of lymph node metastasis in non-small cell lung cancer by integrating single-cell and spatial transcriptomics, revealing complex interactions among tumor stemness, immunoglobulin-high malignant cells, PD-L1 regulation, and immunosuppressive microenvironments. The work not only delivers a high-value data resource but also proposes several translatable mechanistic models, including the heterogeneity of malignant cells with stemness versus immunoglobulin expression, SPP1+IFI30+ macrophage-mediated immune exhaustion, and the immune-exclusion barrier formed by CST1+ fibroblasts. These findings offer new therapeutic targets and biomarkers for precision treatment of NSCLC, particularly suggesting that targeting specific cell subsets or signaling pathways within the TME may overcome current therapeutic bottlenecks in the context of immunotherapy resistance. From bench to bedside, this study lays a solid foundation for developing personalized treatment strategies based on multimodal omics profiling, advancing lung cancer care toward greater precision and efficacy.
