title: MALDI imaging mass spectrometry profiling of N-glycans in formalin-fixed paraffin embedded clinical tissue blocks and tissue microarrays.
abstract: A recently developed matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS) method to spatially profile the location and distribution of multiple N-linked glycan species in frozen tissues has been extended and improved for the direct analysis of glycans in clinically derived formalin-fixed paraffin-embedded (FFPE) tissues. Formalin-fixed tissues from normal mouse kidney, human pancreatic and prostate cancers, and a human hepatocellular carcinoma tissue microarray were processed by antigen retrieval followed by on-tissue digestion with peptide N-glycosidase F. The released N-glycans were detected by MALDI-IMS analysis, and the structural composition of a subset of glycans could be verified directly by on-tissue collision-induced fragmentation. Other structural assignments were confirmed by off-tissue permethylation analysis combined with multiple database comparisons. Imaging of mouse kidney tissue sections demonstrates specific tissue distributions of major cellular N-linked glycoforms in the cortex and medulla. Differential tissue distribution of N-linked glycoforms was also observed in the other tissue types. The efficacy of using MALDI-IMS glycan profiling to distinguish tumor from non-tumor tissues in a tumor microarray format is also demonstrated. This MALDI-IMS workflow has the potential to be applied to any FFPE tissue block or tissue microarray to enable higher throughput analysis of the global changes in N-glycosylation associated with cancers.
authors.affiliation: Department of Cell and Molecular Pharmacology and Experimental Therapeutics and MUSC Proteomics Center, Medical University of South Carolina, Charleston, South Carolina, United States of America.
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Powers
authors.affiliation: Department of Cell and Molecular Pharmacology and Experimental Therapeutics and MUSC Proteomics Center, Medical University of South Carolina, Charleston, South Carolina, United States of America.
authors.forename: Benjamin A
authors.initials: BA
authors.lastname: Neely
authors.affiliation: Hollings Cancer Center Biorepository and Tissue Analysis Resource, Medical University of South Carolina, Charleston, South Carolina, United States of America.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Shao
authors.affiliation: Laboratory of Cancer Immunodiagnostics, Van Andel Research Institute, Grand Rapids, Michigan, United States of America.
authors.forename: Huiyuan
authors.initials: H
authors.lastname: Tang
authors.affiliation: Departments of Pathology and Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, Virginia, United States of America.
authors.forename: Dean A
authors.initials: DA
authors.lastname: Troyer
authors.affiliation: Drexel University College of Medicine, Department of Microbiology and Immunology and Drexel Institute for Biotechnology and Virology, Doylestown, Pennsylvania, United States of America.
authors.forename: Anand S
authors.initials: AS
authors.lastname: Mehta
authors.affiliation: Laboratory of Cancer Immunodiagnostics, Van Andel Research Institute, Grand Rapids, Michigan, United States of America.
authors.forename: Brian B
authors.initials: BB
authors.lastname: Haab
authors.affiliation: Department of Cell and Molecular Pharmacology and Experimental Therapeutics and MUSC Proteomics Center, Medical University of South Carolina, Charleston, South Carolina, United States of America; Hollings Cancer Center Biorepository and Tissue Analysis Resource, Medical University of South Carolina, Charleston, South Carolina, United States of America.
authors.forename: Richard R
authors.initials: RR
authors.lastname: Drake
mesh_terms: D000328:Adult; D000818:Animals; D002240:Carbohydrate Sequence; D006528:Carcinoma, Hepatocellular / Q000737:chemistry* / Q000473:pathology; D005260:Female; D005557:Formaldehyde; D006801:Humans; D006868:Hydrolysis; D007668:Kidney / Q000033:anatomy & histology / Q000737:chemistry; D008113:Liver Neoplasms / Q000737:chemistry* / Q000473:pathology; D008297:Male; D051379:Mice; D008875:Middle Aged; D008969:Molecular Sequence Data; D010190:Pancreatic Neoplasms / Q000737:chemistry* / Q000473:pathology; D010232:Paraffin; D016612:Paraffin Embedding; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase / Q000737:chemistry; D011134:Polysaccharides / Q000032:analysis* / Q000737:chemistry; D011471:Prostatic Neoplasms / Q000737:chemistry* / Q000473:pathology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D046888:Tissue Array Analysis; D016707:Tissue Fixation
chemical_list: D011134:Polysaccharides; D005557:Formaldehyde; D010232:Paraffin; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase