Protein Glycosylation: An Important Tool for Diagnosis or Early Detection of Diseases

Abstract Currently surveillance strategies have inadequate performance for the early detection of hepatocellular carcinoma (HCC). Protein glycosylation is a potential source of biomarkers to differentiate between cirrhosis and HCC. We performed a comprehensive LC-PRM-MS approach where a targeted parallel reaction monitoring (PRM) strategy was coupled to a powerful LC system to study the microheterogeneity of haptoglobin (Hp) extracted from 15 patients with cirrhosis and 15 with HCC. We found that our strategy was able to identify a large number of isomeric N-glycopeptides mainly located in the glycosylation site Asn207. Nine out of twelve N-glycopeptides, located in the Asn207 site, had significant differences in abundance between patients with cirrhosis and HCC (p < 0.05). The area under the curve (AUC) of alpha-fetoprotein (AFP) was alone 0.85, which improved to 0.95 (95% CI: 0.88, 1) when NLF_5613 Isomer 1 was combined with AFP. When comparing the early HCC vs. cirrhosis, four sialylated-fucosylated glycopeptides better estimated AUCs with respect to AFP (AUCAFP = 0.66, and AUCN−glycopeptides = 0.86, 0.84, 0.88, and 0.80, respectively). Further large scale validation of glycopeptides for the early detection of HCC is warranted.

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Serum glycoproteomic-based liquid biopsy for the detection of pancreatic ductal adenocarcinoma.

Journal of Clinical Oncology ◽

10.1200/jco.2020.38.4_suppl.763 ◽

2020 ◽

Vol 38 (4_suppl) ◽

pp. 763-763

Author(s):

Pashtoon Murtaza Kasi ◽

Ling Shen ◽

Prasanna Ramachandran ◽

Kaitlynn Moser ◽

Gege Xu ◽

...

Keyword(s):

Early Detection ◽

Pancreatic Ductal Adenocarcinoma ◽

Pelvic Mass ◽

Protein Glycosylation ◽

Classification Model ◽

Ductal Adenocarcinoma ◽

Linear Regression Models ◽

Serum Samples ◽

Liquid Biopsies ◽

Differential Abundance

763 Background: Non-invasive biomarkers with high sensitivity and specificity would be of great value for patients with Pancreatic Ductal Adenocarcinoma (PDAC). This would aid in early detection and serve other purposes that 'liquid biopsies' are being explored in. Besides circulating tumor DNA (ctDNA) and methylation markers, glycosylation markers hold great potential promise. We developed a novel workflow using high-resolution quantification of site-specific protein glycosylation by liquid chromatography and tandem mass spectrometry to evaluate the clinical utility of glycoprotemics signature for patients with PDAC. Methods: Serum samples from newly diagnosed PDAC patients and controls were obtained from a commercial biobank (Indivumed, Hamburg, Germany), and a panel of 504 glycan motifs, representing 73 previously reported proteomic markers, was determined. Age-adjusted generalized linear regression models were used to evaluate the differential abundance of each marker, and stepwise variable selection was used for model construction. Results: We analyzed 45 PDAC and 136 control samples. PDAC patients (60% male) had a mean age of 67 (±11) years. with 4.4%, 71.1%, 4.4%, and 20% at stage 1, 2, 3,4, respectively. Controls were women with benign histology after pelvic mass surgery; with a mean age of 61 (±11) years. Twenty-six glycoproteomic markers showed statistically highly significant differential abundance among cases and controls (p<1e-4 each) and were highly reproducible(Pearson’s r > 0.85), which were glycoforms in proteins that have previously been found to be associated with PDAC. Fourteen of these markers displayed >0.8 area under the curve of the receiver operating characteristic (AUC). Multivariate logistic regression modeling with backward selection yielded a classification model with an AUC of 0.94 (95% CI: 0.89-0.99), sensitivity of 91% (95% CI: 75-97%) and specificity of 86% (95% CI: 81-92%). Conclusions: Circulating glycoproteomic biomarkers may be useful in the early detection and clinical management of PDAC patients; offering a new platform to explore and validate.

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