Nitrotyrosine, inducible nitric oxide synthase (iNOS), and endothelial nitric oxide synthase (eNOS) are increased in

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An Orthotopic Mouse Model of Anaplastic Thyroid Carcinoma
07:01

An Orthotopic Mouse Model of Anaplastic Thyroid Carcinoma

Published on: April 17, 2013

A Patel1, C Fenton, R Terrell

  • 1Department of Pediatrics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.

Journal of Endocrinological Investigation
|September 21, 2002
PubMed

Insights

Nitric oxide (NO) is elevated in thyroid tumors and autoimmune thyroid diseases. This suggests NO plays a role in thyroid tumor vascularization and disease progression.

Area of Science:

  • Endocrinology
  • Oncology
  • Immunology

Background:

  • Nitric oxide (NO) is a critical cell signaling molecule involved in vascular tone regulation.
  • NO is synthesized by three main isoforms of nitric oxide synthase (NOS): inducible (iNOS), endothelial (eNOS), and neuronal (nNOS).

Purpose of the Study:

  • To investigate the role of NO in the growth of thyroid tumors.
  • To determine the expression levels of iNOS, eNOS, and nitrotyrosine (N-TYR) in various thyroid lesions.

Main Methods:

  • Immunohistochemical staining for iNOS, eNOS, and N-TYR was performed on 41 papillary thyroid carcinomas (PTC), 9 follicular thyroid carcinomas (FTC), and 15 benign thyroid lesions.
  • Staining intensity was quantified by two independent examiners on a scale of 1 (absent) to 4 (intense).
  • Correlations between N-TYR staining and vascular endothelial growth factor (VEGF) and lymphocyte count were analyzed.

Main Results:

  • Elevated N-TYR, iNOS, and eNOS staining were observed in benign adenomas, PTC, FTC, and autoimmune thyroid lesions compared to normal thyroid tissue.
  • N-TYR staining showed a positive correlation with VEGF expression and lymphocyte infiltration.
  • Preliminary data suggested a potential link between moderate-to-intense N-TYR staining and recurrent disease in carcinomas.

Conclusions:

  • NO is produced in benign and malignant thyroid tumors, as well as in autoimmune thyroid diseases.
  • These findings suggest that NO may be important for the vascularization of thyroid tumors and in the pathogenesis of autoimmune thyroid conditions.

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