背景 胰腺导管腺癌是一种侵袭性极强的消化系统肿瘤，患者的5年生存率约为13.3%。由于其靶向治疗手段有限，诊疗面临着巨大挑战。近年来，肿瘤微环境在PDAC进展中的作用备受关注，尤其是肿瘤相关巨噬细胞在促进肿瘤生长、侵袭、转移及治疗抵抗中的关键作用。单细胞RNA测序技术的发展为深入解析TME的细胞异质性及功能提供了新工具。本研究旨在探讨SPP1⁺ TAMs在PDAC中的功能及临床意义，以期为改善患者预后提供新策略。
目的 本研究旨在利用scRNA-seq技术分析PDAC患者的肿瘤组织，鉴定SPP1⁺ TAMs的分布特征及其与患者预后的关联，并探究其在肿瘤进展中的作用机制。此外，我们评估了SPP1⁺ TAMs作为预后生物标志物的潜力，以期为PDAC的精准治疗提供新靶点。
方法 我们分析PDAC患者的单细胞测序数据，重点关注其免疫细胞组成与TAMs亚群。利用加权基因共表达网络分析（WGCNA）筛选与预后相关的枢纽基因，并通过基因富集分析（GSEA）探究SPP1的生物学功能。此外，结合体外实验验证SPP1⁺ TAMs对肿瘤细胞的影响，并分析临床样本中SPP1⁺ TAMs的表达与患者预后的相关性。
结果 scRNA-seq分析显示，SPP1⁺ TAMs在PDAC组织中明显增多，且其表达水平升高与患者不良预后有关。WGCNA和GSEA分析表明，SPP1参与细胞因子的正向调控、ECM重构等生物学过程。功能实验证实，TAMs通过SPP1影响肿瘤细胞中CASP1的表达。临床数据分析进一步表明，SPP1-CASP1的高表达与PDAC患者的生存时间减少显著相关。
结论 本研究揭示了SPP1⁺ TAMs在PDAC进展中的关键作用，其通过影响肿瘤微环境促进恶性表型，并与患者不良预后密切相关。SPP1⁺ TAMs可作为PDAC预后评估的潜在生物标志物，靶向干预该亚群可能成为改善PDAC治疗的新策略。未来研究需进一步探索SPP1⁺ TAMs的分子机制，并开发针对性的免疫治疗方法，以提高PDAC患者的临床疗效。

Background Pancreatic ductal adenocarcinoma is a highly aggressive malignancy of the digestive system, with a 5-year survival rate of approximately 13.3%. Due to the limited availability of targeted therapies, its clinical management remains a significant challenge. Due to its insidious early symptoms and lack of effective therapeutic targets, clinical management of PDAC remains a significant challenge. In recent years, the tumor microenvironment has garnered increasing attention for its role in PDAC progression, particularly the critical involvement of tumor-associated macrophages in promoting tumor growth, invasion, metastasis, and therapy resistance. The advent of single-cell RNA sequencing technology has provided a powerful tool for dissecting the cellular heterogeneity and functional dynamics of the TME. This study aims to investigate the functional role and clinical significance of SPP1⁺ TAMs in PDAC, with the goal of identifying novel strategies to improve patient outcomes.
Objective This study seeks to utilize scRNA-seq to analyze PDAC tumor tissues, characterize the distribution of SPP1⁺ TAMs, and elucidate their association with patient prognosis. Additionally, we explore the mechanistic contributions of SPP1⁺ TAMs to tumor progression and evaluate their potential as prognostic biomarkers, thereby facilitating the development of precision therapeutics for PDAC.
Methods We analyzed single-cell RNA sequencing data from PDAC patients, with a focus on immune cell composition and TAM subpopulations. Weighted gene co-expression network analysis (WGCNA) was employed to identify prognosis-associated key genes, while gene set enrichment analysis (GSEA) was conducted to investigate the biological functions of SPP1. Additionally, in vitro experiments were performed to validate the impact of SPP1⁺ TAMs on tumor cells, and clinical samples were analyzed to assess the correlation between SPP1⁺ TAMs expression and patient prognosis.
Results Single-cell RNA sequencing (scRNA-seq) revealed a significant enrichment of SPP1⁺ tumor-associated macrophages (TAMs) in PDAC tissues, with elevated expression levels correlating with poor patient prognosis. Weighted gene co-expression network analysis (WGCNA) and gene set enrichment analysis (GSEA) demonstrated that SPP1 is involved in biological processes including cytokine positive regulation and extracellular matrix (ECM) remodeling. Functional validation experiments confirmed that TAMs regulate CASP1 expression in tumor cells via SPP1. Furthermore, clinical data analysis established a significant association between high SPP1-CASP1 co-expression and reduced survival time in PDAC patients.
Conclusion This study highlights the pivotal role of SPP1⁺ TAMs in PDAC progression, demonstrating their contribution to malignant phenotypes through TME modulation and their strong association with adverse clinical outcomes. SPP1⁺ TAMs may serve as a potential prognostic biomarker, and targeted intervention against this subset could represent a novel therapeutic strategy for PDAC. Future research should further elucidate the molecular mechanisms of SPP1⁺ TAMs and develop tailored immunotherapeutic approaches to enhance clinical efficacy in PDAC patients.