The plasma exosomal miR-1180-3p serves as a novel potential diagnostic marker for cutaneous melanoma

Background Exosomes are a promising tool in disease detection because they are noninvasive, cost-effective, sensitive and stable in body fluids. MicroRNAs (miRNAs) are the main exosomal component and participate in tumor development. However, the exosomal miRNA profile among Asian melanoma patients remains unclear. Methods Exosomal miRNAs from the plasma of melanoma patients (n = 20) and healthy individuals (n = 20) were isolated and subjected to small RNA sequencing. Real-time PCR was performed to identify the differential miRNAs and to determine the diagnostic efficiency. Proliferation, scratch and Transwell assays were performed to detect the biological behavior of melanoma cells. Results Exosomal miRNA profiling revealed decreased miR-1180-3p expression as a potential diagnostic marker of melanoma. The validation group of melanoma patients (n = 28) and controls (n = 28) confirmed the diagnostic efficiency of miR-1180-3p. The level of miR-1180-3p in melanoma cells was lower than that in melanocytes. Accordingly, the level of miR-1180-3p was negatively associated with the proliferation, migration and invasion of melanoma cells. Functional analysis and target gene prediction found that ST3GAL4 was a potential target and highly expressed in melanoma tissues and was negatively regulated by miR-1180-3p. Knockdown of ST3GAL4 hindered the malignant phenotype of melanoma cells. Conclusions This study indicates that reduced exosomal miR-1180-3p in melanoma patient plasma is a promising diagnostic marker and provides novel insight into melanoma development. Keywords: Melanoma, Plasma, Exosome, miR-1180-3p, Diagnostic marker, ST3GAL4