Extracellular vesicles (EVs) are mediators of the immune system response. Encapsulated in EVs, microRNAs can be transferred between cancer and immune cells. To define the potential effects of EVs originated from squamous cell carcinoma cells on immune system response, we performed microRNA profiling of EVs released from two distinct cell lines and treated dendritic cells derived from circulating monocytes (mono-DCs) with these EVs. We confirmed the internalization of EVs by mono-DCs and the down-regulation of microRNA mRNA targets in treated mono-DCs. Differences in surface markers of dendritic cells cultivated in the presence of EVs indicated that their content disrupts the maturation process. Additionally, microRNAs known to interfere with dendritic cell function, and detected in EVs, matched microRNAs from squamous cell carcinoma patients’ plasma: miR-17-5p in oropharyngeal squamous cell carcinoma, miR-21 in oral squamous cell carcinoma, miR-16, miR-24, and miR-181a circulating in both oral and oropharyngeal squamous cell carcinoma, and miR-23b, which has not been previously described in plasma of head and neck squamous cell carcinoma, was found in plasma from patients with these cancer subtypes. This study contributes with insights on EVs in signaling between cancer and immune cells in squamous cell carcinoma of the head and neck.

细胞外囊泡（EV）是免疫系统反应的介质。封装在 EV 中的 microRNA 可以在癌症和免疫细胞之间转移。为了确定源自鳞状细胞癌细胞的 EV 对免疫系统反应的潜在影响，我们对两种不同细胞系释放的 EV 进行了 microRNA 分析，并用这些 EV 处理了循环单核细胞 (mono-DC) 衍生的树突状细胞。我们证实了单 DC 细胞内化 EV 以及经处理的单 DC 细胞中 microRNA mRNA 靶标的下调。在 EV 存在下培养的树突状细胞表面标记物的差异表明它们的内容破坏了成熟过程。此外，已知干扰树突状细胞功能并在 EV 中检测到的 microRNA，与鳞状细胞癌患者血浆中的匹配 microRNA：口咽鳞状细胞癌中的 miR-17-5p、口腔鳞状细胞癌中的 miR-21、miR-16、 miR-24 和 miR-181a 在口腔和口咽鳞状细胞癌中循环，而 miR-23b 在头颈鳞状细胞癌血浆中尚未被描述，但在这些癌症亚型患者的血浆中被发现。这项研究有助于深入了解头颈部鳞状细胞癌中癌症和免疫细胞之间的 EV 信号传导。