Weiser Tobias, Hoch Cosima C, Petry Julie, Shoykhet Maria, Schmidl Benedikt, Yazdi Mina, Hachani Khouloud, Mergner Julia, Theodoraki Marie-Nicole, Azimzadeh Omid, Multhoff Gabriele, Bashiri Dezfouli Ali, Wollenberg Barbara
Department of Otolaryngology, Head and Neck Surgery, TUM School of Medicine and Health, Technical University of Munich (TUM), Munich, Germany.
Pharmaceutical Biotechnology, Department of Pharmacy, Ludwig-Maximilians-Universität (LMU), Munich, Germany.
Cell Commun Signal. 2025 May 1;23(1):210. doi: 10.1186/s12964-025-02215-x.
Head and neck squamous cell carcinoma (HNSCC) is an aggressive malignancy, characterized by poor clinical outcomes, primarily driven by high rate of locoregional recurrence and metastasis. Extensive heterogeneity among the tumor cells as well as modulation of a highly immunosuppressive tumor microenvironment shape cancer progression. Shedding of extracellular vesicles (EVs) derived from tumor cells is a critical mediator of the disease initiating horizontal transfer of tumor components into platelets. This triggers platelet activation and thromboinflammation fueling tumor progression through multiple mechanisms.
HNSCC-derived EVs isolated from HNSCC cell lines (SAS, UD-SCC 5) using size exclusion chromatography and characterized via flow cytometry, electron microscopy, nanoparticle tracking analysis and Western blotting, were used to induce platelet activation and aggregation, measured by aggregometry, flow cytometry, as well as the release of chemokines and Adenosine triphosphate, which were quantified using enzyme-linked immunosorbent assays (ELISA). Mechanistic investigations included inhibitor assays, thrombin activity measurements, and proteomic analyses.
We could show that EVs do not activate platelets through the FcγRIIa-IgG axis but platelet activation and aggregation is induced in a calcium-dependent manner, primarily mediated by EV-associated tissue factor. Proteomic analysis confirmed the presence of tissue factor in these vesicles, implicating its involvement in initiating the coagulation cascade, that leads to platelet activation and aggregation. This process was characterized by delayed aggregation kinetics and relied on thrombin activation, as the inhibition of thrombin and its receptors reduced platelet aggregation. HNSCC-derived EVs are pivotal in establishing a prothrombotic environment by promoting platelet activation and aggregation through tissue factor-dependent thrombin generation.
These findings indicate a therapeutic potential of targeting EV-mediated pathways as a therapeutic approach to alleviate thrombotic complications in HNSCC patients. Subsequent animal studies will be crucial to validate and extend these observations, providing deeper insight into their clinical implications.
头颈部鳞状细胞癌（HNSCC）是一种侵袭性恶性肿瘤，临床预后较差，主要原因是局部区域复发和转移率高。肿瘤细胞之间广泛的异质性以及高度免疫抑制的肿瘤微环境的调节影响癌症进展。肿瘤细胞衍生的细胞外囊泡（EVs）脱落是疾病的关键介质，可将肿瘤成分水平转移至血小板。这触发血小板活化和血栓炎症，通过多种机制促进肿瘤进展。
使用尺寸排阻色谱法从HNSCC细胞系（SAS、UD-SCC 5）中分离出HNSCC衍生的EVs，并通过流式细胞术、电子显微镜、纳米颗粒跟踪分析和蛋白质印迹进行表征，用于诱导血小板活化和聚集，通过凝集测定法、流式细胞术以及趋化因子和三磷酸腺苷的释放来测量，使用酶联免疫吸附测定（ELISA）对其进行定量。机制研究包括抑制剂测定、凝血酶活性测量和蛋白质组学分析。
我们发现EVs并非通过FcγRIIa-IgG轴激活血小板，而是以钙依赖的方式诱导血小板活化和聚集，主要由EV相关的组织因子介导。蛋白质组学分析证实这些囊泡中存在组织因子，表明其参与启动凝血级联反应，进而导致血小板活化和聚集。该过程的特征是聚集动力学延迟，并且依赖于凝血酶激活，因为抑制凝血酶及其受体可减少血小板聚集。HNSCC衍生的EVs通过组织因子依赖性凝血酶生成促进血小板活化和聚集，在建立促血栓形成环境中起关键作用。
这些发现表明，靶向EV介导的途径作为一种治疗方法，在减轻HNSCC患者血栓形成并发症方面具有治疗潜力。后续的动物研究对于验证和扩展这些观察结果至关重要，将更深入地了解其临床意义。
