Oral Presentation 23rd Annual Lorne Proteomics Symposium 2018

Uncovering N-linked protein glycosylation changes during prostate cancer progression (#28)

Rebeca Sakuma 1 2 , Daniel Quina 1 , Christopher Ashwood 2 , Hannes Hinneburg 2 , Saulo Recuero 3 , Miguel Srougi 3 , Katia Ramos 3 , Nicolle Packer 2 , Morten Thaysen-Andersen 2 , Giuseppe Palmisano 1
  1. Department of Parasitology, University of Sau Paulo, Sao Paulo, SP, Brazil
  2. Department of Molecular Sciences, Macquarie University, Sydney, NSW, Australia
  3. Laboratório de Investigação Médica da Disciplina de Urologia , Faculdade de Medicina da USP, Sao Paulo, SP, Brazil

Prostate cancer (PCa) is the second most common cancer in men worldwide. Gleason score classification is the most important predictor of PCa outcomes and is influential in determining patient treatment options. However, tumour heterogeneity, biopsy-sampling error, and variations in biopsy interpretation are still key challenges for accurate prognostication, leading to significant overtreatment with associated costs and morbidity. Changes in the glycosylation profile and the corresponding glycosylation enzymes were previously described to be associated with PCa development and progression, but until this point have been only studied in isolated PCa cell cultures and not in cancer tissues. In this study we aimed to accurately map the N-linked protein glycosylation in PCa tissues during disease progression. Membrane proteins were extracted from a cohort of fresh PCa tissue samples, which were accurately grouped into five PCa disease stages (n = 10 per group) as well as tissues from benign hyperplasia patients (n=5). Porous graphitised carbon–liquid chromatography (PGC–LC) and negative polarity ion trap tandem mass spectrometry was used to quantitatively map native N-glycans after PNGase F-based release and reduction. A total of 85 unique N-glycan compositions and 188 biosynthetically-related structural isomers were detected across the prostate tissues. Complex fucosylated and sialylated N-glycans were the most abundant structures. Preliminary data points towards an increase of highly branched (tri- and tetra-antennary) fucosylated and sialylated glycans and a concomitant decrease in high mannose structures during PCa progression. Paucimannosidic glycans were shown with increased abundance across stages of PCa but surprisingly with decreased abundance in end-stage PCa.  By integrating the results from the glycome data and lectin blotting analysis with the N-glycan biosynthetic pathway, we provide an in-depth and system-wide characterisation of changes in the N-glycosylation during PCa progression. These changes can be further explored as potential diagnostic and prognostic marker for PCa detection and development.