Interrelated overexpression of endothelial and inducible nitric oxide synthases, endothelin-1 and angiogenic factors in human papillary thyroid carcinoma.
OBJECTIVE
Nitric oxide (NO) and endothelin-1 (ET-1) are involved in carcinogenesis. Overexpression of the ET-1 axis has been demonstrated in papillary thyroid carcinoma (PTC). This study investigated the expression of NO synthases (NOS) and their relationship with expression of ET-1 and angiogenic markers in PTC.


METHODS
Expression of NOS, angiogenic markers [vascular endothelial growth factor (VEGF), angiopoietin-1 and angiopoietin-2] and their receptors was studied in surgical thyroid samples obtained from 22 patients aged 15-68 years. Three groups were constituted: normal thyroid (n = 5), Hashimoto's thyroiditis (n = 9) and PTC (n = 8).


RESULTS
Immunohistochemistry disclosed NOS2 and NOS3 immunoreactivity in PTC cells, the percentage of positive cells being greater than normal (P < 0.02). Real-time quantitative polymerase chain reaction (RTQ-PCR) showed that NOS2 and NOS3 mRNA levels were, respectively, increased (P < 0.02) by 2.6 +/- 0.6 and 4.2 +/- 1.1 times in PTC. RTQ-PCR demonstrated that VEGF, its receptors VEGFR-1 and VEGFR-2, and angiopoietin-2 and its receptor (Tie2) were also overexpressed (P < 0.05) in PTC. Correlations were found between ET-1 expression and that of NOS2, angiopoietin-1 and -2 (P < 0.05). NOS2 mRNA levels also correlated with those of NOS3 and angiopoietin-2 (P < 0.05). In thyroiditis, NOS2 immunoreactivity was observed in inflammatory cells whereas NOS2 mRNA levels were 12.1 +/- 1.6 times higher than normal (P < 0.005).


CONCLUSIONS
This study revealed an activation of the NO pathway in thyroid carcinoma, which is interrelated to the ET-1 axis, both systems being overexpressed in concert with angiogenic factors. This global system might play a role in carcinogenesis and constitutes a potential target for anticancer therapy.
Donckier
Julian E
JE
Department of Internal Medicine, Surgery and Pathology, University Hospital of Mont-Godinne, Université Catholique de Louvain, Yvoir, Belgium. julian.donckier@mint.ucl.ac.be
Michel
Luc
L
Delos
Monique
M
Havaux
Xavier
X
Van Beneden
Ronald
R
D000293:Adolescent; D000328:Adult; D000368:Aged; D042683:Angiopoietin-1 / Q000032:analysis / Q000235:genetics; D042702:Angiopoietin-2 / Q000032:analysis / Q000235:genetics; D002291:Carcinoma, Papillary / Q000737:chemistry*; D016022:Case-Control Studies; D019332:Endothelin-1 / Q000032:analysis*; D005260:Female; D050031:Hashimoto Disease / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D008875:Middle Aged; D019001:Nitric Oxide Synthase / Q000032:analysis* / Q000235:genetics; D052247:Nitric Oxide Synthase Type II / Q000032:analysis / Q000235:genetics; D052250:Nitric Oxide Synthase Type III / Q000032:analysis / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D042787:Receptor, TIE-2 / Q000032:analysis / Q000235:genetics; D013964:Thyroid Neoplasms / Q000737:chemistry*; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis* / Q000235:genetics; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000032:analysis / Q000235:genetics; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000032:analysis / Q000235:genetics
D042683:Angiopoietin-1; D042702:Angiopoietin-2; D019332:Endothelin-1; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D042787:Receptor, TIE-2; D040281:Vascular Endothelial Growth Factor Receptor-1; D040301:Vascular Endothelial Growth Factor Receptor-2