title: Pax-8-PPAR-γ fusion protein in thyroid carcinoma.
abstract: Thyroid carcinoma is the most common endocrine malignancy, and its incidence is continuing to increase. Most thyroid carcinomas contain one of several known driver mutations, such as the Val600Glu substitution in B-Raf, Ras mutations, RET gene fusions, or PAX8-PPARG gene fusions. The PAX8-PPARG gene fusion results in the production of a Pax-8-PPAR-γ fusion protein (PPFP), which is found in approximately one-third of follicular thyroid carcinomas, as well as some follicular-variant papillary thyroid carcinomas. In vitro and in vivo evidence indicates that PPFP is an oncoprotein. Although specific mechanisms of action remain to be defined, PPFP is considered to act as a dominant-negative inhibitor of wild-type PPAR-γ and/or as a unique transcriptional activator of subsets of PPAR-γ-responsive and Pax-8-responsive genes. Detection of the fusion transcript in thyroid nodule biopsy specimens can aid clinical decision-making when cytological findings are indeterminate. The PPAR-γ agonist pioglitazone is highly therapeutic in a transgenic mouse model of PPFP-positive thyroid carcinoma, suggesting that PPAR-γ agonists might be beneficial in patients with PPFP-positive thyroid carcinomas.
authors: Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, University of Michigan, 5560 MSRB-2, SPC 5678, 1150 West Medical Drive, Ann Arbor, MI 48109, USA.
authors: Priyadarshini
authors: P
authors: Raman
authors: Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, University of Michigan, 5560 MSRB-2, SPC 5678, 1150 West Medical Drive, Ann Arbor, MI 48109, USA.
authors: Ronald J
authors: RJ
authors: Koenig
mesh_terms: D000818:Animals; D014408:Biomarkers, Tumor / Q000235:genetics*; D050939:Gene Fusion / Q000235:genetics*; D006801:Humans; D000072636:PAX8 Transcription Factor; D047495:PPAR gamma / Q000235:genetics*; D051761:Paired Box Transcription Factors / Q000235:genetics*; D013964:Thyroid Neoplasms / Q000175:diagnosis / Q000235:genetics*
chemical_list: D014408:Biomarkers, Tumor; D000072636:PAX8 Transcription Factor; C083325:PAX8 protein, human; D047495:PPAR gamma; D051761:Paired Box Transcription Factors