Expression and localization of aminopeptidase A, aminopeptidase N, and dipeptidyl peptidase IV in benign and malignant human prostate tissue

• Published in: The Prostate 1997-12, Vol.33 (4), p.225-232
• Main Authors: Bogenrieder, Thomas, Finstad, Connie L., Freeman, Ronald H., Papandreou, Christos N., Scher, Howard I., Albino, Anthony P., Reuter, Victor E., Nanus, David M.
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; aminopeptidase; Aminopeptidases - analysis; Aminopeptidases - immunology; Antibodies, Monoclonal - immunology; Biological and medical sciences; Biopsy; Bone Neoplasms - enzymology; Bone Neoplasms - pathology; Bone Neoplasms - secondary; CD13 Antigens - analysis; CD13 Antigens - immunology; Dipeptidyl Peptidase 4 - analysis; Dipeptidyl Peptidase 4 - immunology; Epithelium - enzymology; Epithelium - pathology; Glutamyl Aminopeptidase; Humans; Immunohistochemistry; Liver Neoplasms - enzymology; Liver Neoplasms - pathology; Liver Neoplasms - secondary; Lung Neoplasms - enzymology; Lung Neoplasms - pathology; Lung Neoplasms - secondary; Lymph Nodes - enzymology; Lymph Nodes - pathology; Male; Medical sciences; Middle Aged; Nephrology. Urinary tract diseases; peptide hydrolases; prostate; Prostate - cytology; Prostate - enzymology; prostate cancer; Prostatic Neoplasms - enzymology; Prostatic Neoplasms - pathology; Soft Tissue Neoplasms - enzymology; Soft Tissue Neoplasms - pathology; Soft Tissue Neoplasms - secondary; Tumors of the urinary system; Urinary tract. Prostate gland
• ISSN: 0270-4137; 1097-0045
• DOI: 10.1002/(SICI)1097-0045(19971201)33:4<225::AID-PROS1>3.0.CO;2-G

BACKGROUND Cell‐surface peptidases are ectoenzymes which regulate the access of bioactive peptides to their receptors on cell membranes. Abnormalities in their expression and function result in altered peptide activity which contribute to neoplastic transformation and/or progression. METHODS Expression of aminopeptidase A (APA), aminopeptidase N (APN, CD13), and dipeptidyl peptidase IV (DPP IV, CD26) was immunohistochemically examined in 20 benign and 33 malignant prostate tissues (19 primaries and 14 metastases). RESULTS Benign prostatic stroma exhibited no APA, APN, or DPP IV immunoreactivity. Stromal cells surrounding prostatic carcinoma cells demonstrated increased APA expression in 24/33 (73%) of tumors. Benign prostatic epithelial cells strongly expressed APN and DPP IV but not APA. In contrast, APN was expressed in >80% of tumor cells in 5/33 (15%) of specimens, heterogeneously expressed (20–80% of cells positive) in 4/33 (12%) of specimens, and minimally expressed or absent in 24/33 (73%) of tumor specimens, with a similar pattern of expression in primary and metastatic tumors. DPP IV was expressed by >80% of tumor cells in 18/19 (95%) of primary prostate cancer specimens, but in only 7/14 (50%) of metastases. CONCLUSIONS These data show that cell‐surface peptidases are differentially expressed by normal prostatic stromal and epithelial cells, with increased expression of APA in the stroma surrounding prostate cancer cells, absent APN expression in most tumor cells, and a decreased frequency of DPP IV expression in metastatic tumors. Further studies will elucidate the biological effects of the presence or loss of cell‐surface peptidases in the benign and malignant prostate. Prostate 33:225–232, 1997. © 1997 Wiley‐Liss, Inc.