Patients with Cholangiocarcinoma Present Specific RNA Profiles in Serum and Urine Extracellular Vesicles Mirroring the Tumor Expression: Novel Liquid Biopsy Biomarkers for Disease Diagnosis
Cholangiocarcinoma (CCA) comprises a group of heterogeneous biliary cancers with
dismal prognosis. The etiologies of most CCAs are unknown, but primary sclerosing cholangitis
(PSC) is a risk factor. Non-invasive diagnosis of CCA is challenging and accurate biomarkers are
lacking. We aimed to characterize the transcriptomic profile of serum and urine extracellular
vesicles (EVs) from patients with CCA, PSC, ulcerative colitis (UC), and healthy individuals. Serum
and urine EVs were isolated by serial ultracentrifugations and characterized by nanoparticle
tracking analysis, transmission electron microscopy, and immunoblotting. EVs transcriptome was
determined by Illumina gene expression array [messenger RNAs (mRNA) and non-coding RNAs
(ncRNAs)]. Differential RNA profiles were found in serum and urine EVs from patients with CCA
compared to control groups (disease and healthy), showing high diagnostic capacity. The
comparison of the mRNA profiles of serum or urine EVs from patients with CCA with the
transcriptome of tumor tissues from two cohorts of patients, CCA cells in vitro, and CCA cellsderived EVs, identified 105 and 39 commonly-altered transcripts, respectively. Gene ontology
analysis indicated that most commonly-altered mRNAs participate in carcinogenic steps. Overall,
patients with CCA present specific RNA profiles in EVs mirroring the tumor, and constituting novel
promising liquid biopsy biomarkers