Centre de Microscopie Electronique Stéphanois, CMES, Faculty of Medicine, Jean Monnet University, Saint-Etienne 42023, France.
INSERM, U1059, Sainbiose, Saint-Étienne 42023, France.
Microscopy (Oxf). 2023 Oct 9;72(5):450-454. doi: 10.1093/jmicro/dfad007.
Small extracellular vesicles (EVs) are characterized by the membrane expression of CD63, CD81 and CD9 tetraspanins. Their size is inferior to 200 nm. They share the same characteristics as the native cells and are found in human fluids. Specific membrane protein biomarkers expressed on small EV are useful for the diagnosis of tumoural pathologies. Clear cell renal cell carcinoma (CCRCC) is diagnosed by imaging examinations and/or tissue biopsy. Carbonic anhydrase IX (CAIX) is a powerful biomarker of CCRCC. The detection of CAIX on small EV from the urine of patients could constitute a liquid biopsy for CCRCC. We have set up a specific protocol for the preparation, the immunostaining characterization and the transmission electron microscopy observation of small EVs isolated from the urine of CCRCC patients. The background labelling was significantly reduced. We successfully detected biomarkers on urinary small EVs from CCRCC patients. This technique could be extended with antibodies directed against other EV biomarkers for the detection and the monitoring of cancer diseases.
小细胞外囊泡（EVs）的特征是膜表达 CD63、CD81 和 CD9 四跨膜蛋白。它们的大小小于 200nm。它们与原代细胞具有相同的特征，并存在于人体液中。小 EV 上表达的特定膜蛋白生物标志物可用于肿瘤病理的诊断。透明细胞肾细胞癌（CCRCC）通过影像学检查和/或组织活检进行诊断。碳酸酐酶 IX（CAIX）是 CCRCC 的有力生物标志物。从小细胞 EV 中检测到的患者尿液中的 CAIX 可能构成 CCRCC 的液体活检。我们已经建立了一个专门的方案，用于准备、免疫染色特征和从 CCRCC 患者尿液中分离的小 EV 的透射电子显微镜观察。背景标记明显减少。我们成功地从小细胞 EV 中检测到了 CCRCC 患者的生物标志物。该技术可以通过针对其他 EV 生物标志物的抗体进行扩展，以用于癌症疾病的检测和监测。
