title: Variability of protein and phosphoprotein levels in clinical tissue specimens during the preanalytical phase.
abstract: The quality of human tissue specimens can have a significant impact on analytical data sets for biomarker research. The aim of this study was to characterize fluctuations of protein and phosphoprotein levels in human tissue samples during the preanalytical phase. Eleven intestine and 17 liver specimens were surgically resected, aliquoted, and either snap-frozen or fixed in formalin immediately or exposed to different ischemic conditions before preservation. Protein levels in the resultant samples were investigated by reverse phase protein array, Western blot analysis, and liquid chromatography-tandem mass spectrometry. Our data revealed that the degree of sensitivity of proteins and phosphoproteins to delayed preservation varied between different patients and tissue types. For example, up-regulation of phospho-p42/44 MAPK in intestine samples was seen in some patients but not in others. General trends toward up- or down-regulation of most proteins were not evident due to pronounced interpatient variability but signal intensities of only a few proteins, such as cytokeratin 18, were altered from baseline in postresection samples. In contrast, glyceraldehyde 3-phosphate dehydrogenase was found to be stable during periods of cold ischemia. Our study represents a proper approach for studying potential protein fluctuations in tissue specimens for future biomarker development programs.
authors.affiliation: Institute of Pathology, Technische Universität München, Trogerstrasse 18, D-81675 Munich, Germany.
authors.forename: Sibylle
authors.initials: S
authors.lastname: Gündisch
authors.forename: Stefanie
authors.initials: S
authors.lastname: Hauck
authors.forename: Hakan
authors.initials: H
authors.lastname: Sarioglu
authors.forename: Christina
authors.initials: C
authors.lastname: Schott
authors.forename: Christian
authors.initials: C
authors.lastname: Viertler
authors.forename: Marcel
authors.initials: M
authors.lastname: Kap
authors.forename: Tibor
authors.initials: T
authors.lastname: Schuster
authors.forename: Bilge
authors.initials: B
authors.lastname: Reischauer
authors.forename: Robert
authors.initials: R
authors.lastname: Rosenberg
authors.forename: Cornelis
authors.initials: C
authors.lastname: Verhoef
authors.forename: Hans-Joerg
authors.initials: HJ
authors.lastname: Mischinger
authors.forename: Peter
authors.initials: P
authors.lastname: Riegman
authors.forename: Kurt
authors.initials: K
authors.lastname: Zatloukal
authors.forename: Karl-Friedrich
authors.initials: KF
authors.lastname: Becker
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis* / Q000378:metabolism; D001706:Biopsy / Q000379:methods; D015153:Blotting, Western; D002853:Chromatography, Liquid; D050377:Cold Ischemia; D003106:Colon / Q000378:metabolism / Q000473:pathology*; D003110:Colonic Neoplasms / Q000737:chemistry / Q000175:diagnosis / Q000473:pathology; D015925:Cryopreservation / Q000379:methods; D005557:Formaldehyde / Q000737:chemistry; D006801:Humans; D007421:Intestine, Small / Q000378:metabolism; D053538:Keratin-18 / Q000032:analysis / Q000378:metabolism; D008099:Liver / Q000378:metabolism / Q000473:pathology*; D008113:Liver Neoplasms / Q000556:secondary; D019950:Mitogen-Activated Protein Kinase 1 / Q000032:analysis / Q000378:metabolism; D009362:Neoplasm Metastasis / Q000473:pathology; D009363:Neoplasm Proteins / Q000032:analysis* / Q000378:metabolism; D010750:Phosphoproteins / Q000032:analysis* / Q000378:metabolism; D040081:Protein Array Analysis; D020543:Proteome / Q000032:analysis / Q000378:metabolism; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry; D013997:Time Factors; D016707:Tissue Fixation / Q000379:methods*; D052096:Warm Ischemia / Q000379:methods
chemical_list: D014408:Biomarkers, Tumor; D053538:Keratin-18; D009363:Neoplasm Proteins; D010750:Phosphoproteins; D020543:Proteome; D005557:Formaldehyde; C535150:MAPK1 protein, human; D019950:Mitogen-Activated Protein Kinase 1