Thyroid hormone receptor mutations in cancer.

Area of Science:

• Endocrinology
• Molecular Biology
• Oncology

Background:

• Thyroid hormone receptors (TRs) regulate critical physiological processes including growth, development, differentiation, and metabolic homeostasis.
• TRs function as ligand-dependent transcription factors within the steroid hormone/retinoic acid receptor superfamily.
• Two TR genes (TRalpha and TRbeta) have been identified, with potential roles in carcinogenesis due to their homology with the v-erbA oncogene.

Purpose of the Study:

• To investigate the role of thyroid hormone receptors (TRs) in human cancer development.
• To explore the implications of altered TR expression and somatic mutations in various cancers.
• To examine the oncogenic potential of TRs using transgenic mouse models.

Main Methods:

• Analysis of TR expression at both mRNA and protein levels in cancer tissues.
• Identification of somatic mutations in TR genes in human cancers.
• Generation and study of transgenic mice models, including those overexpressing v-erbA and with targeted TRbeta gene mutations.

Main Results:

• Altered expression of TRs (mRNA and protein) was observed in several human cancers.
• Somatic mutations within TR genes were identified in various human malignancies.
• Transgenic mice overexpressing v-erbA developed hepatocellular carcinoma.
• Homozygous mutant mice with a targeted germline mutation in TRbeta developed metastatic thyroid carcinoma.

Conclusions:

• Thyroid hormone receptors play a critical role in the development and progression of human cancers.
• TRs represent a significant target for understanding and potentially treating various malignancies.
• Evidence from human studies and animal models strongly supports the involvement of TRs in carcinogenesis.