Department of Plastic Surgery, Affiliated People's Hospital of Jiangsu University, 8 Dianli Road, Zhenjiang, 212000, Jiangsu, China.
Department of Rehabilitation, Changshu No. 2 People's Hospital (The 5th Clinical Medical College of Yangzhou University), Changshu, Jiangsu, China.
J Exp Clin Cancer Res. 2021 Mar 19;40(1):107. doi: 10.1186/s13046-021-01906-w.
Cancer-secreted exosomal miRNAs regulates the biological processes of many tumours. The serum level of exosomal miR-106b-5p is significantly increased in melanoma patients. However, the role and molecular mechanisms of exosomal miR-106b-5p in melanoma remains unclear.
Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of miR-106b-5p and EphA4 in melanoma tissues. Transmission electron microscopy (TEM) and western blotting were used to identify exosome. QRT-qPCR and Cy3-labelled miR-106b-5p were used to demonstrated the transmission of melanoma cell-secreted exosomal miR-106b-5p. Western blotting, Immunofluorescence, adhesion, transwell and scratch wound assay were used to explore the role of exosomal miR-106b-5p in melanocytes. Luciferase reporter assays and RNA-Chromatin Immunoprecipitation (ChIP) assay were used to confirm whether erythropoietin-producing hepatocellular carcinoma receptor A4 (EphA4) was a direct target of miR-106b-5p.
We found that miR-106b-5p levels were increased in melanoma tissue, and high miR-106b-5p expression is an independent risk factor for the overall survival of patients with melanoma. miR-106b-5p is enriched in melanoma cell-secreted exosomes and transferred to melanocytes. Exosomal miR-106b-5p promotes the epithelial-to-mesenchymal transition (EMT), migration, invasion and adhesion of melanocytes. Exosomal miR-106b-5p exerted its role by targeting EphA4 to activate the ERK pathway. We demonstrated that exosomal miR-106b-5p promoted melanoma metastasis in vivo through pulmonary metastasis assay.
Thus, melanoma cell-secreted exosomal miR-106b-5p may serve as a diagnostic indicator and potential therapeutic target in melanoma patients.
癌症分泌的外泌体 miRNA 调节着许多肿瘤的生物学过程。黑色素瘤患者血清中外泌体 miR-106b-5p 的水平显著升高。然而，外泌体 miR-106b-5p 在黑色素瘤中的作用和分子机制尚不清楚。
采用实时定量聚合酶链反应（qRT-PCR）检测黑色素瘤组织中 miR-106b-5p 和 EphA4 的表达。采用透射电子显微镜（TEM）和 Western blot 鉴定外泌体。采用 qRT-qPCR 和 Cy3 标记的 miR-106b-5p 证实黑色素瘤细胞分泌的外泌体 miR-106b-5p 的传递。采用 Western blot、免疫荧光、黏附、Transwell 和划痕实验探讨外泌体 miR-106b-5p 在黑素细胞中的作用。采用荧光素酶报告基因实验和 RNA-染色质免疫沉淀（ChIP）实验证实红细胞生成素产生肝细胞受体 A4（EphA4）是否为 miR-106b-5p 的直接靶标。
我们发现 miR-106b-5p 在黑色素瘤组织中表达上调，高 miR-106b-5p 表达是黑色素瘤患者总生存的独立危险因素。miR-106b-5p 富集在黑色素瘤细胞分泌的外泌体中，并转移到黑素细胞。外泌体 miR-106b-5p 促进黑素细胞上皮-间充质转化（EMT）、迁移、侵袭和黏附。外泌体 miR-106b-5p 通过靶向 EphA4 激活 ERK 通路发挥作用。我们通过肺转移实验证明外泌体 miR-106b-5p 在体内促进黑色素瘤转移。
因此，黑色素瘤细胞分泌的外泌体 miR-106b-5p 可能作为黑色素瘤患者的诊断指标和潜在治疗靶点。
