miR-4668-5p is up-regulated in serum of patients with pancreatic cancer

Background: Pancreatic cancer is the most common of gastrointestinal tumor, with a high malignancy and poor prognosis,and early and effective diagnosis is the key for prolonging patient’s overall survival, especially for fluid biopsy.Methods In this study, expression profile array was downloaded from GEO database, and differentially expressed miRNAs in serum were screened from patients with pancreatic cancer and healthy individuals, then co-expressed serum miRNAs in pancreatic cacner patients was analyzed by R software with weighted correlation network analysis(WGCNA) package. Finally, key differentially expressed miRNA was verified in serum of 16 patients with pancreatic cancer and 10 healthy individuals by quantitative real-time PCR (qRT-PCR).Results Results found that there were eleven differentially expressed miRNAs(miR-155-5p, miR-4668-5p, miR-3613-3p, -miR-3201, miR-548ac, miR-486-5p, miR-548a-3p, miR-8084, miR-455-3p, miR-6068, and miR-1246) between pancreatic cancer and healthy individuals. WGCNA results further found that miR-4668-5p has a higher associated modules compared to other differentially expressed miRNAs. Then, the expression level of miR-4668-5p was further verified, and results found that serum miR-4668-5p expression level was significantly higher in patients with pancreatic cancer than that of healthy individuals.Conclusion Our results firstly substantiated that miR-4668-5p was significantly up-regulated in serum of patients with pancreatic cancer, which may be a potential biomarker for pancreatic cancer diagnosis.