title: Altered peptidase activities in thyroid neoplasia and hyperplasia.
abstract: BACKGROUND
  Papillary thyroid carcinoma (PTC), follicular thyroid adenoma (FTA), and thyroid nodular hyperplasia (TNH) are the most frequent diseases of the thyroid gland. Previous studies described the involvement of dipeptidyl-peptidase IV (DPPIV/CD26) in the development of thyroid neoplasia and proposed it as an additional tool in the diagnosis/prognosis of these diseases. However, very little is known about the involvement of other peptidases in neoplastic and hyperplastic processes of this gland.
  
  
  METHODS
  The catalytic activity of 10 peptidases in a series of 30 PTC, 10 FTA, and 14 TNH was measured fluorimetrically in tumour and nontumour adjacent tissues.
  
  
  RESULTS
  The activity of DPPIV/CD26 was markedly higher in PTC than in FTA, TNH, and nontumour tissues. Aspartyl aminopeptidase (AspAP), alanyl aminopeptidase (AlaAP), prolyl endopeptidase, pyroglutamyl peptidase I, and aminopeptidase B activities were significantly increased in thyroid neoplasms when compared to nontumour tissues. AspAP and AlaAP activities were also significantly higher in PTC than in FTA and TNH.
  
  
  CONCLUSIONS
  These data suggest the involvement of DPPIV/CD26 and some cytosolic peptidases in the neoplastic development of PTC and FTA. Further studies will help to define the possible clinical usefulness of AlaAP and AspAP in the diagnosis/prognosis of thyroid neoplasms.
authors.affiliation: Department of Nursing I, University School of Nursing, University of the Basque Country, P.O. Box 699, 48080 Bilbao, Bizkaia, Spain ; Department of Physiology, Faculty of Medicine and Dentistry, University of the Basque Country, Bilbao, Spain ; BioCruces Research Institute, Spain.
authors.forename: Gorka
authors.initials: G
authors.lastname: Larrinaga
authors.affiliation: Department of Physiology, Faculty of Medicine and Dentistry, University of the Basque Country, Bilbao, Spain ; BioCruces Research Institute, Spain.
authors.forename: Lorena
authors.initials: L
authors.lastname: Blanco
authors.affiliation: Department of Physiology, Faculty of Medicine and Dentistry, University of the Basque Country, Bilbao, Spain ; BioCruces Research Institute, Spain.
authors.forename: Peio
authors.initials: P
authors.lastname: Errarte
authors.affiliation: Department of Physiology, Faculty of Medicine and Dentistry, University of the Basque Country, Bilbao, Spain ; BioCruces Research Institute, Spain.
authors.forename: Maider
authors.initials: M
authors.lastname: Beitia
authors.affiliation: Department of Physiology, Faculty of Medicine and Dentistry, University of the Basque Country, Bilbao, Spain ; BioCruces Research Institute, Spain.
authors.forename: Begoña
authors.initials: B
authors.lastname: Sanz
authors.affiliation: Department of Nursing I, University School of Nursing, University of the Basque Country, P.O. Box 699, 48080 Bilbao, Bizkaia, Spain ; Department of Physiology, Faculty of Medicine and Dentistry, University of the Basque Country, Bilbao, Spain ; BioCruces Research Institute, Spain.
authors.forename: Itxaro
authors.initials: I
authors.lastname: Perez
authors.affiliation: Department of Nursing I, University School of Nursing, University of the Basque Country, P.O. Box 699, 48080 Bilbao, Bizkaia, Spain ; BioCruces Research Institute, Spain.
authors.forename: Amaia
authors.initials: A
authors.lastname: Irazusta
authors.affiliation: Department of Nursing I, University School of Nursing, University of the Basque Country, P.O. Box 699, 48080 Bilbao, Bizkaia, Spain.
authors.forename: Clara E
authors.initials: CE
authors.lastname: Sánchez
authors.affiliation: Department of Otolaryngology, Basurto University Hospital, Bilbao, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Santaolalla
authors.affiliation: BioCruces Research Institute, Spain ; Department of Anatomic Pathology, Cruces University Hospital, Barakaldo, Bizkaia, Spain.
authors.forename: Leire
authors.initials: L
authors.lastname: Andrés
authors.affiliation: BioCruces Research Institute, Spain ; Department of Anatomic Pathology, Cruces University Hospital, Barakaldo, Bizkaia, Spain.
authors.forename: José I
authors.initials: JI
authors.lastname: López
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000201:enzymology*; D000328:Adult; D018826:CD13 Antigens / Q000378:metabolism; D002291:Carcinoma, Papillary / Q000201:enzymology*; D018819:Dipeptidyl Peptidase 4 / Q000378:metabolism*; D005260:Female; D043384:Glutamyl Aminopeptidase / Q000378:metabolism; D006801:Humans; D006965:Hyperplasia / Q000201:enzymology; D008297:Male; D008875:Middle Aged; D000085822:Prolyl Oligopeptidases; D011751:Pyroglutamyl-Peptidase I / Q000378:metabolism; D012697:Serine Endopeptidases / Q000378:metabolism; D013961:Thyroid Gland / Q000201:enzymology* / Q000473:pathology; D013964:Thyroid Neoplasms / Q000201:enzymology*
chemical_list: D018826:CD13 Antigens; D043384:Glutamyl Aminopeptidase; C042807:DPP4 protein, human; D018819:Dipeptidyl Peptidase 4; D011751:Pyroglutamyl-Peptidase I; D012697:Serine Endopeptidases; C000705287:PREPL protein, human; D000085822:Prolyl Oligopeptidases