No abstract

There is an urgent need for the identification of reliable prognostic biomarkers for patients with intrahepatic cholangiocarcinoma (iCCA) and alterations in N-glycosylation have demonstrated an immense potential to be used as diagnostic strategies for many cancers, including hepatocellular carcinoma (HCC). N-glycosylation is one of the most common post-translational modifications known to be altered based on the status of the cell. N-glycan structures on glycoproteins can be modified based on the addition or removal of specific N-glycan residues, some which have been linked to liver diseases. However, little is known concerning the N-glycan alterations that are associated with iCCA. We characterized the N-glycan modifications quantitatively and qualitatively in three cohorts, consisting of two tissue cohorts: a discovery cohort (n=104 cases) and a validation cohort (n=75), and one independent serum cohort consisting of patients with iCCA, HCC, or benign chronic liver disease (n=67). N-glycan analysis in-situ was correlated to tumor regions annotated on histopathology and revealed that bisected fucosylated N-glycan structures were specific to iCCA tumor regions. These same N-glycan modifications were significantly upregulated in iCCA tissue and serum relative to HCC and bile duct disease, including primary sclerosing cholangitis (PSC) (p<0.0001). N-glycan modifications identified in iCCA tissue and serum were used to generate an algorithm that could be used as a biomarker of iCCA. We demonstrate that this biomarker algorithm quadrupled the sensitivity (at 90% specificity) of iCCA detection as compared to CA19-9, the current “gold standard” biomarker of CCA.

<p>Relative intensity quantification of all N-glycans identified in serum (left row) and tissue (right row) analysis. Red font labeling for N-glycans follows the same trend between serum and tissue.</p>

<p>Patient demographics for A. TMA 1 and B. TMA 2. C. Patient demographics for serum cohort. ALT (Alanine transaminase), AST (aspartate aminotransferase), AFP (Alpha-fetoprotein), and ALP (Alkaline phosphatase). Other liver diseases include nonalcoholic steatohepatitis, hepatitis C with cirrhosis, hepatic adenoma, benign fibrotic gallbladder disease, and diabetes. PSC (Primary Sclerosing cholangitis), HCC (Hepatocellular carcinoma), and OLD (Other liver diseases). Gray shading for missing clinical information. D. Representative N-glycan images of TMA 1 (top) and TMA 2 (bottom) of 2012.717m/z (left) and 1809.646m/z (right). Red boxes select for CCA samples. E. Table details other pathology diagnoses included in TMA 1 with the proposed structure for the N-glycans highly expressed in each. These modifications are characterized based on 1-2 patients.</p>

<p>Peak list of N-glycans detected in tissue (TMA) and serum samples.</p>