title: N-glycan MALDI Imaging Mass Spectrometry on Formalin-Fixed Paraffin-Embedded Tissue Enables the Delineation of Ovarian Cancer Tissues.
abstract: Ovarian cancer is a fatal gynaecological malignancy in adult women with a five-year overall survival rate of only 30%. Glycomic and glycoproteomic profiling studies have reported extensive protein glycosylation pattern alterations in ovarian cancer. Therefore, spatio-temporal investigation of these glycosylation changes may unearth tissue-specific changes that occur in the development and progression of ovarian cancer. A novel method for investigating tissue-specific N-linked glycans is using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) on formalin-fixed paraffin-embedded (FFPE) tissue sections that can spatially profile N-glycan compositions released from proteins in tissue-specific regions. In this study, tissue regions of interest (e.g. tumor, stroma, adipose tissue and necrotic areas) were isolated from FFPE tissue sections of advanced serous ovarian cancers (n = 3). PGC-LC-ESI-MS/MS and MALDI-MSI were used as complementary techniques to firstly generate structural information on the tissue-specific glycans in order to then obtain high resolution images of the glycan structure distribution in ovarian cancer tissue. The N-linked glycan repertoires carried by the proteins in these tissue regions were structurally characterized for the first time in FFPE ovarian cancer tissue regions, using enzymatic peptide-N-glycosidase F (PNGase F) release of N-glycans. The released glycans were analyzed by porous graphitized carbon liquid chromatography (PGC-LC) and collision induced electrospray negative mode MS fragmentation analysis. The N-glycan profiles identified by this analysis were then used to determine the location and distribution of each N-glycan on FFPE ovarian cancer sections that were treated with PNGase F using high resolution MALDI-MSI. A tissue-specific distribution of N-glycan structures identified particular regions of the ovarian cancer sections. For example, high mannose glycans were predominantly expressed in the tumor tissue region whereas complex/hybrid N-glycans were significantly abundant in the intervening stroma. Therefore, tumor and non-tumor tissue regions were clearly demarcated solely on their N-glycan structure distributions.
authors.affiliation: ‡‡Department of Gynaecological Oncology, Royal Adelaide Hospital, Adelaide, South Australia, 5005, Australia;
authors.forename: Arun V
authors.initials: AV
authors.lastname: Everest-Dass
authors.affiliation: From the ‡Faculty of Science, Biomolecular Frontiers Research Centre, Macquarie University, Sydney, NSW, 2109, Australia; ¶Adelaide Proteomics Centre, School of Biological Sciences, University of Adelaide, Adelaide, South Australia, 5005, Australia; ‖Institute for Photonics & Advanced Sensing (IPAS), University of Adelaide, Adelaide, South Australia, 5005, Australia;
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Briggs
authors.affiliation: **Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Pulau Pinang, Malaysia;
authors.forename: Gurjeet
authors.initials: G
authors.lastname: Kaur
authors.affiliation: ‡‡Department of Gynaecological Oncology, Royal Adelaide Hospital, Adelaide, South Australia, 5005, Australia; §§Discipline of Obstetrics and Gynaecology, Robinson Institute, University of Adelaide, Adelaide, South Australia;
authors.forename: Martin K
authors.initials: MK
authors.lastname: Oehler
authors.affiliation: ¶Adelaide Proteomics Centre, School of Biological Sciences, University of Adelaide, Adelaide, South Australia, 5005, Australia; ‖Institute for Photonics & Advanced Sensing (IPAS), University of Adelaide, Adelaide, South Australia, 5005, Australia; ¶¶Centre for Molecular Pathology, University of Adelaide, Adelaide, South Australia, 5005, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Hoffmann
authors.affiliation: From the ‡Faculty of Science, Biomolecular Frontiers Research Centre, Macquarie University, Sydney, NSW, 2109, Australia; §ARC Centre for Nanoscale BioPhotonics, Macquarie University, Sydney, NSW, 2109, Australia; nicki.packer@mq.edu.au.
authors.forename: Nicolle H
authors.initials: NH
authors.lastname: Packer
mesh_terms: D005260:Female; D054794:Glycomics / Q000379:methods; D006801:Humans; D009928:Organ Specificity; D010051:Ovarian Neoplasms / Q000378:metabolism*; D016612:Paraffin Embedding; D011134:Polysaccharides / Q000032:analysis* / Q000737:chemistry; D040901:Proteomics / Q000379:methods; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D016707:Tissue Fixation
chemical_list: D011134:Polysaccharides