Expression of NIS Protein and mRNA in Thyroid Tumors

Tumors Clinical Trial

Official title:

Significant Intracellular NIS Protein Associated With Low Levels of NIS Messenger RNA in Malignant Thyroid Tumors

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00459498
• Other study ID #: PRN736/02
• Status: Completed
• Phase: N/A
• First received: April 10, 2007
• Last updated: April 10, 2007
• Start date: April 2002
• Est. completion date: October 2006

Study information

• Verified date: April 2007
• Source: University of Sao Paulo
• Contact: n/a
• Is FDA regulated: No
• Health authority: Brazil: Ministry of Health
• Study type: Observational

Clinical Trial Summary

The uptake of iodide by thyroid cells requires the expression of sodium iodide symporter (NIS). Thyroid benign and malignant tumors have low iodide uptake activity. Previous studies of NIS expression with RT-PCR and immunohistochemistry showed divergent data. NIS protein was overexpressed in thyroid cancer. The aim of this study was to investigate the NIS transcript levels and its presence and localization in 30 samples of thyroid tumors (14 benign and 16 malignant) and in their surrounding non-tumoral tissues (NT), by real time RT-PCR and immunohistochemistry, respectively. Our results revealed lower gene expression in 78.6% of the benign tumors and 100% of the carcinomas when compared with the NT samples, using GHPDH as a housekeeping gene. Immunohistochemical staining revealed presence of NIS protein in 100% of the non-tumoral samples, 100% of the benign tumors and 93.75% of the malignant tumors. NIS protein was identified at basolateral membrane in 23.3% of non-tumoral samples, 14.3% of benign and 12.5% of malignant tumors. Stronger cytoplasmatic immunostaining of NIS protein was detected in 64.3% of benign tumors and in 87.5% of malignant tumors when compared to NT. Association between low gene expression and strong cytoplasmatic immunostaining was found in 50% of benign tumors and 87.5% of malignant tumors. We concluded that the reduced NIS gene expression in thyroid tumors associated with strong intracytoplasmatic staining may be due to its incapacity to migrate to cellular membrane.

Description:

The aim of this study was to quantify NIS transcript levels by real time PCR and to determine the presence and cellular localization of NIS protein by immunohistochemistry, in benign and malignant thyroid tumor cells and to compare with their paired surrounding non-tumoral cell. NIS expression was also compared to that of the TSHR

Recruitment information / eligibility

• Status: Completed
• Enrollment: 30
• Est. completion date: October 2006
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years to 80 Years

Eligibility

Inclusion Criteria:

• PAtients with thyroid tumors undergoing surgery for total or partial thyroidectomy

Exclusion Criteria:

• Pregnancy

Study Design

Primary Purpose: Screening, Time Perspective: Cross-Sectional

Related Conditions & MeSH terms

• Thyroid Neoplasms
• Tumors

Locations

Country	Name	City	State
n/a

Sponsors (2)

Lead Sponsor	Collaborator
University of Sao Paulo	Fundação de Amparo à Pesquisa do Estado de São Paulo

References & Publications (1)

Saito T, Endo T, Kawaguchi A, Ikeda M, Katoh R, Kawaoi A, Muramatsu A, Onaya T. Increased expression of the sodium/iodide symporter in papillary thyroid carcinomas. J Clin Invest. 1998 Apr 1;101(7):1296-300. — View Citation