Proteomic Characterization of Urinary Exosomes with Pancreatic Cancer by Phosphatidylserine Imprinted Polymer Enrichment and Mass Spectrometry Analysis

Exosomes,
as carriers of cell-to-cell communication, can serve
as promising biomarkers for probing the early diagnosis of cancer.
Pancreatic cancer is a common malignant tumor of the pancreas with
an insidious onset and difficult early diagnosis. The aim of this
study was to capture exosomes in urine samples by phosphatidylserine-molecularly
imprinted polymers (PS-MIPs). Transmission electron microscopy and
nanoparticle tracking analysis as well as Western blot showed that
our molecularly imprinted material can effectively capture urinary
exosomes. Three parallel tests verified the reproducibility of the
mass spectrometry assay and the stability of the material capture
efficiency. Mass Spectrometry with nontargeted proteomics was combined
to show differentially expressed proteins in exosomes between 5 pancreatic
cancer patients and 5 healthy controls. The most significant changes
in the proteomic profile in pancreatic cancer patients compared to
healthy controls were the overexpression of SLC9A3R1, SPAG9, and ferritin
light chain (FTL) These proteins may have an important role in diagnosis
and prognostic assessment, supporting further scientific and clinical
studies on pancreatic cancer.