Neutrophils act as a non-negligible regulator in the initiation and progression of malignancies, playing bifacial roles in the process. Thus, to understand the heterogeneity of tumor-associated neutrophils (TANs) comprehensively in advanced non-small cell lung cancer (NSCLC) at single-cell resolution is necessary and urgent.
We applied single-cell RNA-sequencing (scRNA-seq) to portray the subtype-specific transcriptome landscape of TANs in advanced NSCLC using nine freshly obtained specimens. The scRNA-seq data were further processed for pseudo-time analysis to depict the developmental trajectory of TANs. Meanwhile, the interplay between TANs and other cell types within tumor microenvironment (TME) was revealed by intercellular interaction analysis.
Seven distinct TAN subtypes were defined, of which, the N7 cluster was the most distinctive one exhibiting unique and independent characteristics of gene signatures and potential functions. N1 and N5 clusters were considered well differentiated and mature neutrophils based on CXCR2 expression and pseudo-time patterns, and both accounted for relatively high proportions in lung adenocarcinoma. Besides, certain genes related to neutrophil differentiation were discovered, and we also found that TAN subtypes interacted most closely with macrophages through chemokine signaling pathways within TME.
Our study refined TAN subtypes and mapped the transcriptome landscape of TANs at single-cell resolution in advanced NSCLC, collectively indicating the heterogeneity of TANs in NSCLC. Neutrophil differentiation- and maturation-related genes were also disclosed, which shed light on different functions of subclones in tumor immune escape, and may further provide novel targets for immunotherapy.
The Ethical Committee of Shanghai Pulmonary Hospital Affiliated to Tongji University.
This work was supported by grants from National Natural Science Foundation of China (No. 81902314), Natural Science Foundation of Shanghai (No. 20ZR1447100), and Clinical Research Plan of Shanghai Hospital Development Center (No. SHDC2020CR4001).
All authors have declared no conflicts of interest.