Selective expression of inducible nitric oxide synthase in human prostate carcinoma.
BACKGROUND
Nitric oxide (NO) is synthesized by inducible nitric oxide synthase (iNOS) and plays an important role in tumor growth and angiogenesis. NO generation by iNOS also influences the cytotoxicity of macrophages and tumor-induced immunosuppression. Before now, the expression of iNOS in prostate carcinoma tissue had not been determined.


METHODS
In this study, tissue sections from 16 patients with prostate carcinoma were studied immunohistochemically and compared with tissue specimens from 10 patients with benign hyperplasia.


RESULTS
Positive iNOS immunostaining was detected in all sections from patients with prostate carcinoma. The malignant epithelial cells were highly positive. The antibody against iNOS also marked round cells, which had the same cell shape as that observed for macrophages. These cells were located in stroma and epithelium adjacent to tumor islets. However, round cells in benign tissue stained negative for iNOS. None of the benign hyperplasia specimens stained positive for iNOS immunohistochemically.


CONCLUSIONS
Prostate carcinoma tissue had a high iNOS content, whereas benign tissue did not. The authors suggest that epithelial iNOS expression can be used as a specific immunohistochemical marker for prostate carcinoma. NO generation by iNOS may play multiple roles in the development of this disease.
Klotz
T
T
Department of Urology, University of Cologne, Germany.
Bloch
W
W
Volberg
C
C
Engelmann
U
U
Addicks
K
K
D000230:Adenocarcinoma / Q000378:metabolism* / Q000601:surgery; D000368:Aged; D000595:Amino Acid Sequence; D004790:Enzyme Induction; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008969:Molecular Sequence Data; D019001:Nitric Oxide Synthase / Q000096:biosynthesis*; D052247:Nitric Oxide Synthase Type II; D011470:Prostatic Hyperplasia / Q000378:metabolism* / Q000601:surgery; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000601:surgery
C496319:NOS2 protein, human; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II