title: Targeted Proteomics for Multiplexed Verification of Markers of Colorectal Tumorigenesis.
abstract: Targeted proteomic methods can accelerate the verification of multiple tumor marker candidates in large series of patient samples. We utilized the targeted approach known as selected/multiple reaction monitoring (S/MRM) to verify potential protein markers of colorectal adenoma identified by our group in previous transcriptomic and quantitative shotgun proteomic studies of a large cohort of precancerous colorectal lesions. We developed SRM assays to reproducibly detect and quantify 25 (62.5%) of the 40 selected proteins in an independent series of precancerous and cancerous tissue samples (19 adenoma/normal mucosa pairs; 17 adenocarcinoma/normal mucosa pairs). Twenty-three proteins were significantly up-regulated (n= 17) or downregulated (n= 6) in adenomas and/or adenocarcinomas, as compared with normal mucosa (linear fold changes ≥ ±1.3, adjustedpvalue <0.05). Most changes were observed in both tumor types (up-regulation of ANP32A, ANXA3, SORD, LDHA, LCN2, NCL, S100A11, SERPINB5, CDV3, OLFM4, and REG4; downregulation of ARF6 and PGM5), and a five-protein biomarker signature distinguished neoplastic tissue from normal mucosa with a maximum area under the receiver operating curve greater than 0.83. Other changes were specific for adenomas (PPA1 and PPA2 up-regulation; KCTD12 downregulation) or adenocarcinoma (ANP32B, G6PD, RCN1, and SET up-regulation; downregulated AKR1B1, APEX1, and PPA1). Some changes significantly correlated with a few patient- or tumor-related phenotypes. Twenty-two (96%) of the 23 proteins have a potential to be released from the tumors into the bloodstream, and their detectability in plasma has been previously reported. The proteins identified in this study expand the pool of biomarker candidates that can be used to develop a standardized precolonoscopy blood test for the early detection of colorectal tumors.
authors.affiliation: From the ‡Institute of Molecular Cancer Research, University of Zurich, Switzerland.
authors.forename: Anuli Christiana
authors.initials: AC
authors.lastname: Uzozie
authors.affiliation: §Functional Genomics Center Zurich, University/ETH Zurich, Zurich, Switzerland.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Selevsek
authors.affiliation: §Functional Genomics Center Zurich, University/ETH Zurich, Zurich, Switzerland.
authors.forename: Asa
authors.initials: A
authors.lastname: Wahlander
authors.affiliation: §Functional Genomics Center Zurich, University/ETH Zurich, Zurich, Switzerland.
authors.forename: Paolo
authors.initials: P
authors.lastname: Nanni
authors.affiliation: §Functional Genomics Center Zurich, University/ETH Zurich, Zurich, Switzerland.
authors.forename: Jonas
authors.initials: J
authors.lastname: Grossmann
authors.affiliation: ¶Institute of Surgical Pathology, University of Zurich, Switzerland.
authors.forename: Achim
authors.initials: A
authors.lastname: Weber
authors.affiliation: ‖ Gastroenterology and Endoscopy Unit, Hospital of Cremona, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Buffoli
authors.affiliation: From the ‡Institute of Molecular Cancer Research, University of Zurich, Switzerland; marra@imcr.uzh.ch.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Marra
mesh_terms: D000236:Adenoma / Q000378:metabolism*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood / Q000378:metabolism*; D002853:Chromatography, Liquid; D015179:Colorectal Neoplasms / Q000378:metabolism*; D030541:Databases, Genetic; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D008875:Middle Aged; D040901:Proteomics / Q000379:methods*; D012372:ROC Curve; D053719:Tandem Mass Spectrometry
chemical_list: D014408:Biomarkers, Tumor