These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Increased expression of AP2 and Sp1 transcription factors in human thyroid tumors: a role in NIS expression regulation?
    Author: Chiefari E, Brunetti A, Arturi F, Bidart JM, Russo D, Schlumberger M, Filetti S.
    Journal: BMC Cancer; 2002 Dec 10; 2():35. PubMed ID: 12475396.
    Abstract:
    BACKGROUND: Sodium/iodide symporter (NIS) is a key protein in iodide transport by thyroid cells and this activity is a prerequisite for effective radioiodide treatment of thyroid cancer. In the majority of thyroid cancers, however, iodide uptake is reduced, probably as a result of decreased NIS protein expression. METHODS: To identify the mechanisms that negatively affect NIS expression in thyroid tumors, we performed electrophoresis mobility shift assays and immunoblot analysis of nuclear protein extracts from normal and tumoral thyroid tissues from 14 unrelated patients. RESULTS: Two proteins closely related to the transcription factors AP2 and Sp1 were identified in the nuclear extracts. Expression of both AP2 and Sp1 in nuclear extracts from thyroid tumors was significantly higher than that observed in corresponding normal tissues. CONCLUSION: These observations raise the possibility that NIS expression, and subsequently iodide transport, are reduced in thyroid tumors at least in part owing to alterations in the binding activity of AP2 and Sp1 transcription factors to NIS promoter.
    [Abstract] [Full Text] [Related] [New Search]