Single-Cell Profiling Reveals Heterogeneity of Primary and Lymph Node Metastatic Tumors and Immune Cell Populations and Discovers Important Prognostic Significance of CCDC43 in Oral Squamous Cell Carcinoma

Abstract

Although substantial progress has been made in biological research and clinical treatment in recent years, the clinical prognosis of oral squamous cell carcinoma (OSCC) is still not satisfactory. Tumor immune microenvironment (TIME) is a potential target, which plays an essential role in the response of anti-tumor immunity and immunotherapy. In this study, we used scRNA-seq data, revealing the heterogeneity of TIME between metastatic and primary site. We found that in the metastatic site, the content of cytotoxic T cells and classical activated macrophages (M1 macrophages) increases significantly, while alternately activated macrophages (M2 macrophages) and inflammatory cancer-associated fibroblasts (iCAFs) decrease, which may be due to the increased immunogenicity of OSCC cells in the metastatic site and the changes in some signal pathways. We also found that iCAFs may recruit alternately activated macrophages (M2 macrophages) by secreting CXCL12. Then, we described a regulatory network for communication between various TIME cells centered on OSCC cells, which can help to clarify the possible mechanism of lymph node metastasis in OSCC cells. By performing pseudotime trajectory analysis, we found that the expression CCDC43 is upregulated in more advanced OSCC cells and is an independent prognostic factor for poor living conditions. Other than this, the high expression of CCDC43 may impair the antitumor immunity of the human body and promote the metastasis of OSCC cells. Our research provides a profound insight into the immunological study of OSCC and an essential resource for future drug discovery.

Heterogeneity of cancer-associated fibroblasts in head and neck squamous cell carcinoma: opportunities and challenges

“…Related study found that CAFs in HNSCC mainly comprise myCAFs that play key roles in HNSCC progression, including matrix remodeling, the production of growth factors and cytokines, and metabolic effects [60]. CXCL12 is a vital chemokine, which can promote cancer cells proliferation, angiogenesis, and metastasis [61], and Wang et al found that CXCL12 is mainly secreted by iCAFs in OSCC [59]. That means iCAFs may facilitate HNSCC progression via some mechanisms.…”

“…The roles of CAFs are as varied as their identification markers, and they have dynamically heterogeneous impacts on cancer at various stages [54][55][56].According recent research, CAFs were divided into "myofibroblastic CAFs" (myCAFs), "inflammatory CAFs" (iCAFs)and "antigen-presenting CAFs" (apCAFs) according to their characteristic marker genes, and these CAFs subclusters showed distinct phenotypes enriched in myofibroblast function, ECM remodeling and antigen-presenting function respectively [57][58][59]. Among them, myCAFs are characterized by myofibroblasts with high α-SMA expression and enrichment in smooth muscle contraction [57], and ECM-receptor interaction, vascular smooth muscle contraction, and focal adhesion are enriched in myCAFs [59]. Related study found that CAFs in HNSCC mainly comprise myCAFs that play key roles in HNSCC progression, including matrix remodeling, the production of growth factors and cytokines, and metabolic effects [60].…”

Single-cell transcriptome and TCR profiling revealed the immunosuppression caused by Macrophages and T cells in the chemoresistant oral tongue squamous cell carcinoma

“…Clustering identi ed differentially expressed genes for clusters utilizing the Wilcoxon Rank Sum test, with absolute log2 fold change (FC) ≥ 0.5 and a minimum cell population fraction of 0.3 in either of the two populations. The R package SingleR (version 2.2.0) was then used to further annotate single cells by leveraging reference transcriptomic datasets of pure cell types to infer the cell of origin of each single cell independently, while manually con rming the cell types using known canonical cell markers from previous studies [23]. Table 2 provides information about the biomarkers.…”

“…Single-cell RNA sequencing is an innovative technique for sequencing the transcriptome of a single cell as a speci c research object and performing bioinformatics statistical analysis of the resulting data [22]. Using conventional technologies such as micro uidics and barcode labeling, numerous cells can be promptly and e ciently labeled, sequenced, and analyzed, and the analysis software can easily capture gene expression pro les and differences at the single-cell resolution [23]. We collected three samples of fresh tongue tissue from patients diagnosed with primary and recurrent OSCC for this study.…”

Lymph node metastasis in oral squamous cell carcinoma: Where we are and where we are going

“…However, there is still a long way to go for the clinical translation of these laboratory findings. Single‐cell RNA sequencing (scRNA‐seq) and tissue microarray have proven beneficial for better understanding the heterogeneity and connections between metastatic lymph nodes and primary OSCC 108,109 . However, current research has not yet comprehensively and systematically elucidated the patterns of LNM occurrence and development in OSCC.…”