Project description:Background: Lung cancer is the one of the malignant tumors with the highest morbidity and mortality in China and even the world. The overall five-year survival rate is about 20%, and most patients die of tumor metastasis. Non-small cell lung cancer (NSCLC) is the main pathologic type of lung cancer. The development and metastasis of tumor cells is influenced by the interaction with other cells in the environment. To explore the molecular expression spectrum of tumor and tumor microenvironment can provide clues for the mechanism of tumor progression, drug resistance and metastasis. The emergence of single cell ribonucleic acid sequencing (scRNA-seq) technology can explore the genomic and transcriptional characteristics of different tumor cells at the single cell resolution, which can reveal the molecular characteristics of individual cells and the relationship between individuals and the environment, thus making it possible to further understand the genesis and progression of NSCLC. Methods: ScRNA-seq (10X genomics) was used to detect single-cell transcriptomes in 2 patients with NSCLC, aiming to more accurately explore the effects of the transcriptome in a single cell on its function and the progression of NSCLC, and to find new cell subtypes or molecular targets for drug therapy. Results: The tumor tissue, distant normal tissue, and lymph node tissue of 2 patients with NSCLC were analyzed. A total of 43779 cells were analyzed, which were classified into epithelial cells, T lymphocytes, natural killer cells (NK cells), B lymphocytes, myeloid cells, endothelial cells, fibroblasts, and MAST cells. Tumor cells showed signature markers of epithelial (EPCAM, KRT7, KRT8, KRT18, CDH1, etc.) and tumor (KRT19, ENO2, SLC25A2, UBE2C, etc.) markers. Additionally, the acquired immunity is activated in the tumor microenvironment, while the innate immunity is exhausted. The proportion of B lymphocytes increases, and immunosuppressive tumor-infiltrating B cells (CD19+, MS4A1+, CD69+, CD27-, CR2-) are observed, which are capable of participating in the induction of exhausted regulatory T cells. The proportion of cytotoxic CD8+ T cells in T lymphocyte population decreases, and the number of exhausted regulatory T cells and exhausted follicular helper T cells increases. They all express LAG3+, TIGIT+, PDCD1+, CTLA4+, and other suppressive markers, showing a state of immunosuppression. High expression of WFDC2 in T cells has a significant effect on prognosis. NK cells show a state of depletion, not only in number, but also gradually transform into a less cytotoxic subtype (CD56+, CD16-). In addition, myeloid cells also play an important role in disrupting the anti-tumor immune response. Tumor associated macrophages (TAMs) and plasmacytoid dendritic cells (pDCs) are enriched in tumor tissue. TAMs highly express anti-inflammatory markers (APOE+, C1QA+, C1QB+) and proliferative markers (MKI67+, STMN1+, NUSAP1+), which are closely related to tumor progression and metastasis. TAMs show M2 type polarization of macrophages, which has a tumor promoting effect. At the same time, TAMs express monocyte markers, which may be transformed from monocyte derived macrophages. Macrophages highly express CXCL8, CCL2, and other genes, which participate in Toll-like receptor, NOD-like receptor signaling pathway, and have a significant impact on the prognosis. pDCs are immunosuppressive cells. The high expression of LILR family genes and GZMB in pDCs may lead to poor tumor antigen presentation of lung squamous cell carcinoma. Dendritic cells highly express NLRP3, IRF7, and other genes, which participate in C-type lectin receptor, Toll-like receptor, NOD-like receptor signaling pathway, and have a significant impact on the prognosis. In addition to the immune system, fibroblasts in the stroma also show characteristics of immunosuppressive cells. Enrichment of Cancer-associated fibroblasts (CAFs) in tumor can promote immunosuppression and tumor progression. Among them, a special subtype termed inflammatory CAFs is found, which participate in the process of extracellular matrix remodeling, angiogenesis, and cell migration, resulting in promoting tumor progression. Fibroblasts highly express FN1, TIMP1, and hub gene SPP1, which interact with macrophages, participate in PI3K-AKT pathway, and have a significant impact on the prognosis. Conclusions: NSCLC shows heterogeneous tumor microenvironment. A variety of immune cells and stromal cells together lead to immunosuppressive environment and promote the progression of tumor. This study enhances our understanding of molecular and cellular dynamics of NSCLC, and reveals potential diagnostic and therapeutic targets in tumor microenvironment.
2023-12-31 | GSE198099 | GEO
