Increased APN/CD13 and acid aminopeptidase activities in head and neck squamous cell carcinoma.
BACKGROUND
Involvement of peptidases in carcinogenic processes of several tumor types has been investigated in recent years. Head and neck squamous cell carcinoma (HNSCC) is one of the most common cancers worldwide and accounts for more than 90% of all head and neck cancers. Increased understanding of its pathophysiology has led to implication of several proteinases, specially matrix metalloproteinases, in its genesis, growth, and dissemination. However, very little is known about involvement of peptidases in this neoplasm.


METHODS
Seventeen HNSCC tissue samples were selected for the study. Tumor and normal tissue samples were frozen for enzymatic study. The catalytic activity for a pool of peptidases (PSA, APN/CD13, APB, APA, Asp-AP, CAP, DPPIV/CD26, NEP/CD10, and PGI) was measured fluorometrically.


RESULTS
The activity of 2 cell surface aminopeptidases (APN/CD13 and APA) and a cytosolic aminopeptidase (Asp-AP) was significantly increased in HNSCC tissues.


CONCLUSIONS
These data show the involvement of cell surface and cytosolic peptidases in the mechanisms underlying HNSCC.
Department of Physiology, School of Medicine and Dentistry, University of the Basque Country, Bilbao, Spain.
Itxaro
I
Pérez
Adolfo
A
Varona
Lorena
L
Blanco
Javier
J
Gil
Francisco
F
Santaolalla
Aitor
A
Zabala
Agustin Martínez
AM
Ibarguen
Jon
J
Irazusta
Gorka
G
Larrinaga
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018826:CD13 Antigens / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000201:enzymology* / Q000503:physiopathology; D005260:Female; D043384:Glutamyl Aminopeptidase / Q000378:metabolism*; D006258:Head and Neck Neoplasms / Q000201:enzymology* / Q000503:physiopathology; D006801:Humans; D007150:Immunohistochemistry; D007822:Laryngeal Neoplasms / Q000201:enzymology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged
D018826:CD13 Antigens; D043384:Glutamyl Aminopeptidase