Huiying Wan,1 Ling Zhong,1 Tian Xia,2 Dingding Zhang3 

1Department of Dermatology, Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu, People’s Republic of China; 2Department of Pathology, Air Force Hospital of Western Theater Command, Chengdu, People’s Republic of China; 3Sichuan Provincial Key Laboratory for Genetic Disease, Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu, People’s Republic of China

Correspondence: Tian Xia, Department of Pathology, Air Force Hospital of Western Theater Command, No. 1 Gongnongyuan Street, Jinjiang District, Chengdu City, Sichuan Province, 610031, People’s Republic of China, Tel +86-18030761839, Email yours_summer2023@126.com Dingding Zhang, Sichuan Provincial Key Laboratory for Genetic Disease, Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, No. 32 West Second Section of First Ring Road, Qingyang District, Chengdu City, Sichuan Province, 610072, People’s Republic of China, Tel +86-18981838863, Email zhangdd25@126.com

Background: Exosomes contain abundant circular RNAs (circRNAs), playing an important role in intercellular communication. However, the function and underlying molecular mechanism of exosomal circRNAs in foot metastatic melanoma remain unclear.
Methods: Twelve differentially expressed exosomal circRNAs between patients with metastatic and primary foot melanoma were screened through high-throughput sequencing, and their expression levels were detected by the real-time reverse transcriptase-polymerase chain reaction (RT-qPCR). CircRNA102927 silencing and overexpression A2058 cell line was constructed, and the effects of circRNA102927 on cell proliferation, apoptosis, migration, invasion, and epithelial-mesenchymal transition (EMT) were assessed using cell counting kit-8 (CCK-8), flow cytometry, wound healing, Transwell, and Western blot assays, respectively.
Results: Twelve differentially expressed exosomal circRNAs were screened and ROC curve showed that six circRNAs could be used as the diagnostic biomarkers for metastatic melanoma. Melanoma-secreted exosomes induced the differentiation of CD4+ T cells into Treg cells. CircRNA102927 was highly expressed in metastatic melanomas. Functionally, circRNA102927 silencing inhibited proliferation, EMT, migration, and invasion in metastatic melanoma cells, while promoting apoptosis. Meanwhile, overexpression of circRNA102927 had the opposite effects.
Conclusion: Our investigation suggests that silencing exosomal circRNA102927 may suppress foot melanoma metastasis by inhibiting invasiveness, EMT and promoting apoptosis.

Keywords: exosomal circRNAs, CircRNA102927, foot metastatic melanoma, metastasis