癌相关成纤维细胞（CAFs）通过分泌涉及肿瘤浸润免疫细胞以及肿瘤微环境中其他免疫成分调节的多种效应因子来发挥其免疫抑制作用，从而促进肿瘤发生、进展、转移和耐药。虽然大量研究表明CAFs在头颈鳞状细胞癌（HNSCC）发展中扮演着关键调节作用，但对CAFs与HNSCC预后相关性的研究有限。本研究通过单变量Cox分析、LASSO回归、逐步回归和多变量Cox分析，发现一个含有8个CAFs相关基因的HNSCC预后标志物。进一步验证人类HNSCC原代CAF和四种人类HNSCC细胞系的验证结果表明，这8个基因确实是CAF的特异性标志物。依据这8个CAFs相关基因标志物，高风险和低风险组间的免疫细胞浸润差异分析提示CAF在时空域的调节作用，进一步揭示了其潜在的预后作用。这8个CAFs相关基因标志物在不同独立验证队列中的验证显示其是预后的有效标志物。通过Kaplan-Meier(K-M)分析确认低风险组较高的总生存率（OS），表明这一标志物可作为一种无创性的HNSCC预后预测工具。低风险组CD8+ T细胞、滤泡辅助性T细胞、树突状细胞（DC）等肿瘤杀伤免疫细胞浸润水平较高，而M0巨噬细胞和激活肥大细胞（MCs）等促肿瘤细胞浸润水平较低。深入探究CAFs与免疫细胞之间的复杂机制，寻找潜在的调节靶点，可能为接下来的靶向免疫治疗提供新证据。这些结果表明，这8个CAFs相关基因标志物是评估HNSCC时间的有力指标，可能为临床医生提供新的、可靠的预后预测指标，指导HNSCC患者的治疗和临床决策。同时，CAFs相关基因有望成为HNSCC肿瘤标志物和有效靶向。© 2023 The Authors.

Cancer-associated fibroblasts (CAFs) can exert their immunosuppressive effects by secreting various effectors that are involved in the regulation of tumor-infiltrating immune cells as well as other immune components in the tumor immune microenvironment (TIME), thereby promoting tumorigenesis, progression, metastasis, and drug resistance. Although a large number of studies suggest that CAFs play a key regulatory role in the development of head and neck squamous cell carcinoma (HNSCC), there are limited studies on the relevance of CAFs to the prognosis of HNSCC. In this study, we identified a prognostic signature containing eight CAF-related genes for HNSCC by univariate Cox analysis, lasso regression, stepwise regression, and multivariate Cox analysis. Our validation in primary cultures of CAFs from human HNSCC and four human HNSCC cell lines confirmed that these eight genes are indeed characteristic markers of CAFs. Immune cell infiltration differences analysis between high-risk and low-risk groups according to the eight CAF-related genes signature hinted at CAFs regulatory roles in the TIME, further revealing its potential role on prognosis. The signature of the eight CAF-related genes was validated in different independent validation cohorts and all showed that it was a valid marker for prognosis. The significantly higher overall survival (OS) in the low-risk group compared to the high-risk group was confirmed by Kaplan-Meier (K-M) analysis, suggesting that the signature of CAF-related genes can be used as a non-invasive predictive tool for HNSCC prognosis. The low-risk group had significantly higher levels of tumor-killing immune cell infiltration, as confirmed by CIBERSORT analysis, such as CD8+ T cells, follicular helper T cells, and Dendritic cells (DCs) in the low-risk group. In contrast, the level of infiltration of pro-tumor cells such as M0 macrophages and activated Mast cells (MCs) was lower. It is crucial to delve into the complex mechanisms between CAFs and immune cells to find potential regulatory targets and may provide new evidence for subsequently targeted immunotherapy. These results suggest that the signature of the eight CAF-related genes is a powerful indicator for the assessment of the TIME of HNSCC. It may provide a new and reliable potential indicator for clinicians to predict the prognosis of HNSCC, which may be used to guide treatment and clinical decision-making in HNSCC patients. Meanwhile, CAF-related genes are expected to become tumor biomarkers and effective targets for HNSCC.© 2023 The Authors.