Expression of nitric oxide synthase type 3 in reflux-induced esophageal lesions.
BACKGROUND
The expression of endothelial constitutive nitric oxide synthase (NOS3) by squamous dysplasia and carcinomas of the head and neck has previously been described. We sought to compare NOS3 expression in squamous mucosa, glandular metaplasia, and adenocarcinoma of the esophagus.


METHODS
Forty paraffin-embedded specimens from 20 patients with adenocarcinoma were stained with anti-NOS3 monoclonal antibody. The percentage of cells stained and the intensity of staining were determined for squamous epithelium, metaplasia, and adenocarcinoma. Staining characteristics were statistically analyzed according to clinical variables.


RESULTS
NOS3 expression was significantly higher in adenocarcinoma and squamous epithelium compared with glandular metaplasia. Among the carcinomas, larger tumor size (T3/4), nodal positivity, and advanced TNM stage (III/IV) significantly correlated with increased NOS3 expression.


CONCLUSIONS
NOS3 is expressed in reflux-induced lesions of the esophagus. Glandular metaplasia shows basal levels of NOS3 that significantly increase with malignant transformation and tumor progression. The role of free radicals in carcinogenesis is being actively studied.
Department of Otolaryngology--Head and Neck Surgery, Northwestern University School of Medicine, Chicago, Illinois, USA.
R
R
Chandra
G K
GK
Haines
B G
BG
Bentz
P
P
Shah
A M
AM
Robinson
J A
JA
Radosevich
D000230:Adenocarcinoma / Q000201:enzymology* / Q000209:etiology* / Q000473:pathology; D000911:Antibodies, Monoclonal; D002294:Carcinoma, Squamous Cell / Q000201:enzymology* / Q000209:etiology / Q000473:pathology; D004938:Esophageal Neoplasms / Q000201:enzymology* / Q000209:etiology* / Q000473:pathology; D005764:Gastroesophageal Reflux / Q000150:complications*; D006801:Humans; D007150:Immunohistochemistry; D009367:Neoplasm Staging; D009375:Neoplasms, Glandular and Epithelial / Q000201:enzymology* / Q000209:etiology / Q000473:pathology; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III; D011230:Precancerous Conditions / Q000201:enzymology* / Q000209:etiology / Q000473:pathology
D000911:Antibodies, Monoclonal; C496314:NOS3 protein, human; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III