Department of Dermatology, University Hospital, Besançon, France.
INSERM, UMR 1231, Laboratoire d'Excellence LipSTIC, Dijon, France.
Exp Dermatol. 2022 Jun;31(6):869-877. doi: 10.1111/exd.14520. Epub 2022 Jan 27.
Exosomes, as potential circulated biomarkers, have recently become a topic of interest in the field of oncology. Immune checkpoint molecule PD-L1 has recently been detected in circulating exosomes from cancer patients. The purpose of this work was to evaluate PD-L1 levels in circulating exosomes (Exo-PD-L1) isolated from patients' plasma suffering from Merkel cell carcinoma (MCC). We conducted a prospective bicentric cohort study. PD-L1 was analysed in circulating exosomes from plasma samples of patients suffering from MCC stage I to IV (according to the AJCC 8). Exosomes from 34 patients corresponding to 66 samples were analysed. PD-L1 was identified in circulating exosomes of MCC patients. Exo-PD-L1 levels of MCC patients were similar to healthy donors and lower than other cancers such as melanoma. Exo-PD-L1 levels tended to be higher in MCC patients with distant metastases. Furthermore, Exo-PD-L1 levels did not significantly vary over the course of the disease whatever the disease course or the response to treatment. This study assessed the presence of PD-L1 in circulating exosomes of MCC patients. The low levels of Exo-PD-L1 and small changes over the course of the disease may be due to the metastatic dissemination of MCC, which is mainly through the skin and lymph nodes rather than blood. PD-L1 was identified in circulating exosomes of MCC patients and tends to be higher in advanced disease. This preliminary study is a proof of concept of PD-L1 detection in circulating exosomes of MCC patients.
外泌体作为潜在的循环生物标志物，最近成为肿瘤学领域的研究热点。免疫检查点分子 PD-L1 最近在癌症患者的循环外泌体中被检测到。本研究旨在评估来自患有 Merkel 细胞癌（MCC）患者血浆的循环外泌体（Exo-PD-L1）中的 PD-L1 水平。我们进行了一项前瞻性的双中心队列研究。分析了 MCC Ⅰ至Ⅳ期（根据 AJCC 8 分期）患者血浆样本中循环外泌体中的 PD-L1。分析了 34 例患者共 66 个样本的外泌体。在 MCC 患者的循环外泌体中鉴定出了 PD-L1。MCC 患者的 Exo-PD-L1 水平与健康供体相似，低于黑色素瘤等其他癌症。远处转移的 MCC 患者的 Exo-PD-L1 水平较高。此外，无论疾病过程或治疗反应如何，Exo-PD-L1 水平在疾病过程中没有显著变化。本研究评估了 MCC 患者循环外泌体中 PD-L1 的存在。Exo-PD-L1 水平较低且疾病过程中变化较小可能是由于 MCC 的转移性播散，主要通过皮肤和淋巴结而不是血液。在 MCC 患者的循环外泌体中鉴定出 PD-L1，并且在晚期疾病中趋于更高。这项初步研究是在 MCC 患者循环外泌体中检测 PD-L1 的概念验证。
