Single-cell transcriptomics analysis of primary lung adenocarcinoma and lymph node metastatic tumors

Although the microenvironment of lymph node metastatic tumors (LNMTs) plays a critical role in the pathogenesis of cancer, systematic studies on the microenvironment of LNMTs in lung adenocarcinoma (LUAD) are lacking. The present study analyzed the single-cell profiles of primary tumors (PTs) and LNMTs in patients with LUAD. The abnormalities in LUAD cells, B cells, T cells, and macrophages in LUAD were additionally analyzed at the single-cell level. The findings revealed that compared to that of the PTs group, the proportion of B cells and macrophages was elevated in the LNMTs group, while the proportion of T and LUAD cells was reduced. These results demonstrated the occurrence of immunosuppression in the microenvironment of LNMTs, and the cell subpopulations were subsequently analyzed to elucidate the underlying changes and associated pathways. The results showed that the abundance of the CREM ⁺ CD8 ⁺ T cell subset was significantly reduced in LNMTs, whereas the proportion of HP ⁺ LUAD cells was significantly increased. In conclusion, the present study characterized the microenvironment of PTs and LNMTs, which may aid in the development of personalized therapeutic strategies for patients with LUAD presenting with lymph node metastases.