Exosomal miRNA signature of pancreatic cyst: Liquid biopsies as indicators of pancreatic cancer.

225Background: Pancreatic cysts are a group of lesions with malignant potential. Currently, there are no consistently reliable biomarkers or imaging modalities to accurately predict biologic behavior of these cysts. We tested the hypothesis that tumor-derived exosomes (better conserved than free miRNA) can be acquired endoscopically from pancreatic cyst fluid and may allow for improved distinction between benign, premalignant and malignant cysts. Methods: Exosomes were isolated and characterised by differential and buoyant centrifugation from pancreatic cyst fluid obtained from 30 patients with pseudocysts (PS), serous cystic (SC), mucinous cysts (MC), intraductal papillary mucinous neoplasms (IPMN), pancreatitis (PA), and pancreatic cancer (PC) , confirmed with imaging and histology. An Illumina TruSeq Small RNA kit was used to construct a small RNA library, and the libraries were sequenced using the Illumina NextSeq 500 platform. The resulting sequencing FASTQ files were analyzed using miRDeep2 to ident...