An integrative single-cell analysis of breast cancer lymph node metastasis has uncovered previously unknown metabolic and immune mechanisms that fuel tumor spread, offering potential new targets for precision therapy. The findings, published in The American Journal of Pathology by Elsevier, provide a detailed map of the metastatic tumor microenvironment and lay the groundwork for future treatment strategies.
Breast cancer is the second most commonly diagnosed cancer worldwide and accounts for approximately 23.8% of cancer cases among women. Lymph node metastasis remains a major determinant of poor prognosis, yet the molecular drivers behind this process have remained incompletely understood.
To address this gap, a collaborative research team constructed a comprehensive “cell–metabolism–immunity” atlas of the lymph node metastatic microenvironment. The team integrated single-cell RNA sequencing with spatial transcriptomics, an advanced technique that maps gene activity while preserving its spatial context within tissues.
The researchers analyzed 78 paired samples of primary breast tumors and matched lymph node metastases, representing more than 360,000 individual cells. Their analysis identified 10 major cell types, including epithelial, immune, and stromal cells, and revealed complex interactions shaping the metastatic niche.
“By combining advanced genetic sequencing and spatial mapping, we have gained unprecedented insights into the dynamic changes and cellular communication patterns within the metastatic microenvironment,” said lead investigator Li Guo, PhD, of the State Key Laboratory of Flexible Electronics (LoFE) and Institute of Advanced Materials (IAM) at Nanjing University of Posts and Telecommunications in China.
Early Disseminated Cancer Cells Identified as Key Drivers
High-resolution clustering analysis revealed a distinct subpopulation of epithelial cells termed early disseminated cancer cells (EDCs). These cells demonstrated enhanced invasive and metastatic potential, driven by metabolic reprogramming processes such as hypoxia response and glycolysis activation.
In addition to metabolic shifts, EDCs were found to modulate the immune environment to their advantage. By reshaping the tumor microenvironment, they promoted tumor cell survival while suppressing anti-tumor immune responses, accelerating metastatic progression.
Further analysis of cell-to-cell communication networks identified a complex three-way interaction among lymphocytes, macrophages, and epithelial cells. In particular, M2-type macrophages were shown to secrete cytokines including CCL22 and CXCL12, fostering an immunosuppressive environment and promoting the malignant transformation of EDCs.
Spatial transcriptomic data confirmed that these interactions form distinct regions within lymph node tissue, overlapping with areas of tumor invasion.
“This systemic interaction between cancer cells, metabolism, and immunity is the core mechanism of lymph node metastasis and a potential therapeutic target,” said co-lead investigator Tingming Liang, PhD, of the School of Life Science at Nanjing Normal University.
Tyrosine Kinase Inhibitors Show Therapeutic Promise
Building on their mechanistic insights, the researchers identified four tyrosine kinase inhibitors targeting M2 macrophages, including pexidartinib hydrochloride and sunitinib malate. These agents inhibit key molecular targets such as CSF1R, effectively blocking immunosuppressive macrophage activity and suppressing lymph node metastasis in preclinical analyses.
“These drugs have demonstrated safety in treating other cancers, and our findings provide a theoretical basis for their application in breast cancer metastasis,” Dr. Guo noted.
The team emphasized that future research will focus on identifying metabolic vulnerabilities in EDCs and integrating clinical data to accelerate the development of innovative therapies aimed at preventing or treating lymph node metastasis in breast cancer patients.
By illuminating the interplay between cancer cell metabolism and immune suppression at single-cell resolution, the study advances understanding of metastatic progression and highlights new avenues for targeted intervention.
