title: Evaluation of formalin-fixed paraffin-embedded tissues in the proteomic analysis of parathyroid glands.
abstract: BACKGROUND
  Proteomic research in the field of parathyroid tissues is limited by the very small dimension of the glands and by the low incidence of cancer lesions (1%). Formalin-fixed paraffin-embedded (FFPE) tissue specimens are a potentially valuable resource for discovering protein cancer biomarkers. In this study we have verified the applicability of a heat induced protein extraction from FFPE parathyroid adenoma tissues followed by a gel-based or gel-free proteomic approach in order to achieve protein separation and identification.
  
  
  RESULTS
  The best results for high quality MS spectra and parameters, were obtained by using a gel-free approach, and up to 163 unique proteins were identified. Similar results were obtained by applying both SDS-out and SDS-out + TCA/Acetone techniques during the gel-free method. Western blot analysis carried out with specific antibodies suggested that the antigenicity was not always preserved, while specific immunoreactions were detected for calmodulin, B box and SPRY domain-containing protein (BSPRY), peroxiredoxin 6 (PRDX 6) and parvalbumin.
  
  
  CONCLUSIONS
  In spite of some limitations mainly due to the extensive formalin-induced covalent cross-linking, our results essentially suggest the applicability of a proteomic approach to FFPE parathyroid specimens. From our point of view, FFPE extracts might be an alternative source, especially in the validation phase of protein biomarkers when a large cohort of samples is required and the low availability of frozen tissues might be constraining.
authors.affiliation: Department of Psychiatry, Neurobiology, Pharmacology and Biotechnology, University of Pisa, Via Bonnanno 6, Pisa, 56126, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Donadio
authors.affiliation: Department of Psychiatry, Neurobiology, Pharmacology and Biotechnology, University of Pisa, Via Bonnanno 6, Pisa, 56126, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Giusti
authors.affiliation: Department of Endocrinology and Metabolism, Orthopedics and Traumatology, Occupational Medicine University of Pisa, Via Paradisa 2, Pisa, 56124, Italy.
authors.forename: Filomena
authors.initials: F
authors.lastname: Cetani
authors.affiliation: Department of Psychiatry, Neurobiology, Pharmacology and Biotechnology, University of Pisa, Via Bonnanno 6, Pisa, 56126, Italy.
authors.forename: Ylenia
authors.initials: Y
authors.lastname: Da Valle
authors.affiliation: Department of Psychiatry, Neurobiology, Pharmacology and Biotechnology, University of Pisa, Via Bonnanno 6, Pisa, 56126, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Ciregia
authors.affiliation: Department of Psychiatry, Neurobiology, Pharmacology and Biotechnology, University of Pisa, Via Bonnanno 6, Pisa, 56126, Italy.
authors.forename: Gino
authors.initials: G
authors.lastname: Giannaccini
authors.affiliation: Department of Endocrinology and Metabolism, Orthopedics and Traumatology, Occupational Medicine University of Pisa, Via Paradisa 2, Pisa, 56124, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Pardi
authors.affiliation: Department of Endocrinology and Metabolism, Orthopedics and Traumatology, Occupational Medicine University of Pisa, Via Paradisa 2, Pisa, 56124, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Saponaro
authors.affiliation: Department of Surgery, University of Pisa, Via Paradisa 2, Pisa, 56124, Italy.
authors.forename: Liborio
authors.initials: L
authors.lastname: Torregrossa
authors.affiliation: Department of Surgery, University of Pisa, Via Paradisa 2, Pisa, 56124, Italy.
authors.forename: Fulvio
authors.initials: F
authors.lastname: Basolo
authors.affiliation: Department of Endocrinology and Metabolism, Orthopedics and Traumatology, Occupational Medicine University of Pisa, Via Paradisa 2, Pisa, 56124, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Marcocci
authors.affiliation: Department of Psychiatry, Neurobiology, Pharmacology and Biotechnology, University of Pisa, Via Bonnanno 6, Pisa, 56126, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Lucacchini