scholarly journals Thyroid Hormone Receptor-β (TRβ) Mediates Runt-Related Transcription Factor 2 (Runx2) Expression in Thyroid Cancer Cells: A Novel Signaling Pathway in Thyroid Cancer

Endocrinology ◽  
2016 ◽  
Vol 157 (8) ◽  
pp. 3278-3292 ◽  
Author(s):  
Frances E. Carr ◽  
Phillip W. L. Tai ◽  
Michael S. Barnum ◽  
Noelle E. Gillis ◽  
Katherine G. Evans ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Thyroid Cancer ◽  
Thyroid Hormone ◽  
Tumor Suppressor ◽  
Hormone Receptor ◽  
Thyroid Hormone Receptor ◽  
Hormone Response ◽  
Thyroid Cells ◽  
Runx2 Expression ◽  
Related Transcription Factor

Dysregulation of the thyroid hormone receptor (TR)β is common in human cancers. Restoration of functional TRβ delays tumor progression in models of thyroid and breast cancers implicating TRβ as a tumor suppressor. Conversely, aberrant expression of the runt-related transcription factor 2 (Runx2) is established in the progression and metastasis of thyroid, breast, and other cancers. Silencing of Runx2 diminishes tumor invasive characteristics. With TRβ as a tumor suppressor and Runx2 as a tumor promoter, a compelling question is whether there is a functional relationship between these regulatory factors in thyroid tumorigenesis. Here, we demonstrated that these proteins are reciprocally expressed in normal and malignant thyroid cells; TRβ is high in normal cells, and Runx2 is high in malignant cells. T3 induced a time- and concentration-dependent decrease in Runx2 expression. Silencing of TRβ by small interfering RNA knockdown resulted in a corresponding increase in Runx2 and Runx2-regulated genes, indicating that TRβ levels directly impact Runx2 expression and associated epithelial to mesenchymal transition molecules. TRβ specifically bound to 3 putative thyroid hormone-response element motifs within the Runx2-P1 promoter (−105/+133) as detected by EMSA and chromatin immunoprecipitation. TRβ suppressed Runx2 transcriptional activities, thus confirming TRβ regulation of Runx2 at functional thyroid hormone-response elements. Significantly, these findings indicate that a ratio of the tumor-suppressor TRβ and tumor-promoting Runx2 may reflect tumor aggression and serve as biomarkers in biopsy tissues. The discovery of this TRβ-Runx2 signaling supports the emerging role of TRβ as a tumor suppressor and reveals a novel pathway for intervention.

scholarly journals Thyroid Hormone Receptor β Suppression of RUNX2 Is Mediated by Brahma-Related Gene 1–Dependent Chromatin Remodeling

Endocrinology ◽  
2018 ◽  
Vol 159 (6) ◽  
pp. 2484-2494 ◽  
Author(s):  
Noelle E Gillis ◽  
Thomas H Taber ◽  
Eric L Bolf ◽  
Caitlin M Beaudet ◽  
Jennifer A Tomczak ◽  
...  
Keyword(s):  
Gene Expression ◽  
Thyroid Hormone ◽  
Chromatin Remodeling ◽  
Hormone Receptor ◽  
Thyroid Hormone Receptor ◽  
Regulation Of Gene Expression ◽  
Related Gene ◽  
Thyroid Cells ◽  
Runx2 Expression ◽  
Thyroid Hormone Receptor Β

Abstract Thyroid hormone receptor β (TRβ) suppresses tumor growth through regulation of gene expression, yet the associated TRβ-mediated changes in chromatin assembly are not known. The chromatin ATPase brahma-related gene 1 (BRG1; SMARCA4), a key component of chromatin-remodeling complexes, is altered in many cancers, but its role in thyroid tumorigenesis and TRβ-mediated gene expression is unknown. We previously identified the oncogene runt-related transcription factor 2 (RUNX2) as a repressive target of TRβ. Here, we report differential expression of BRG1 in nonmalignant and malignant thyroid cells concordant with TRβ. BRG1 and TRβ have similar nuclear distribution patterns and significant colocalization. BRG1 interacts with TRβ, and together, they are part of the regulatory complex at the RUNX2 promoter. Loss of BRG1 increases RUNX2 levels, whereas reintroduction of TRβ and BRG1 synergistically decreases RUNX2 expression. RUNX2 promoter accessibility corresponded to RUNX2 expression levels. Inhibition of BRG1 activity increased accessibility of the RUNX2 promoter and corresponding expression. Our results reveal a mechanism of TRβ repression of oncogenic gene expression: TRβ recruitment of BRG1 induces chromatin compaction and diminishes RUNX2 expression. Therefore, BRG1-mediated chromatin remodeling may be obligatory for TRβ transcriptional repression and tumor suppressor function in thyroid tumorigenesis.

scholarly journals Thyroid hormone receptor beta inhibits the PI3K-Akt-mTOR signaling axis in anaplastic thyroid cancer via genomic mechanisms

2020 ◽  
Author(s):  
Cole D. Davidson ◽  
Eric L. Bolf ◽  
Noelle E. Gillis ◽  
Lauren M. Cozzens ◽  
Jennifer A. Tomczak ◽  
...  
Keyword(s):  
Thyroid Cancer ◽  
Thyroid Hormone ◽  
Tumor Suppressor ◽  
Hormone Receptor ◽  
Thyroid Hormone Receptor ◽  
Anaplastic Thyroid Cancer ◽  
Regulatory Subunit ◽  
Pi3k Signaling ◽  
Phosphoinositide Phosphatase ◽  
Receptor Beta

AbstractThyroid cancer is the most common endocrine malignancy, and the global incidence has increased rapidly over the past few decades. Anaplastic thyroid cancer (ATC) is highly aggressive, dedifferentiated, and patients have a median survival of fewer than six months. Oncogenic alterations in ATC include aberrant PI3K signaling through receptor tyrosine kinase (RTK) amplification, loss of phosphoinositide phosphatase expression and function, and Akt amplification. Furthermore, the loss of expression of the tumor suppressor thyroid hormone receptor beta (TRβ) is strongly associated with ATC. TRβ is known to suppress PI3K in follicular thyroid cancer and breast cancer by binding to the PI3K regulatory subunit p85α. However, the role of TRβ in suppressing PI3K signaling in ATC is not completely delineated. Here we report that TRβ indeed suppresses PI3K signaling in ATC through unreported genomic mechanisms including a decrease in RTK expression and increase in phosphoinositide and Akt phosphatase expression. Furthermore, the reintroduction and activation of TRβ in ATC enables an increase in the efficacy of the competitive PI3K inhibitors LY294002 and buparlisib on cell viability, migration, and suppression of PI3K signaling. These findings not only uncover additional tumor suppressor mechanisms of TRβ but shed light into the implication of TRβ status and activation on inhibitor efficacy in ATC tumors.Abstract FigureGraphical abstract

scholarly journals Thyroid hormone receptor beta inhibits the PI3K-Akt-mTOR signaling axis in anaplastic thyroid cancer cell lines via genomic mechanisms

2021 ◽  
Author(s):  
Cole D Davidson ◽  
Eric L Bolf ◽  
Noelle E Gillis ◽  
Lauren M Cozzens ◽  
Jennifer A Tomczak ◽  
...  
Keyword(s):  
Thyroid Cancer ◽  
Thyroid Hormone ◽  
Tumor Suppressor ◽  
Cell Lines ◽  
Hormone Receptor ◽  
Thyroid Hormone Receptor ◽  
Anaplastic Thyroid Cancer ◽  
Regulatory Subunit ◽  
Pi3k Signaling ◽  
Receptor Beta

Abstract Thyroid cancer is the most common endocrine malignancy, and the global incidence has increased rapidly over the past few decades. Anaplastic thyroid cancer (ATC) is highly aggressive, dedifferentiated, and patients have a median survival of fewer than six months. Oncogenic alterations in ATC include aberrant PI3K signaling through receptor tyrosine kinase (RTK) amplification, loss of phosphoinositide phosphatase expression and function, and Akt amplification. Furthermore, the loss of expression of the tumor suppressor thyroid hormone receptor beta (TRβ) is strongly associated with ATC. TRβ is known to suppress PI3K in follicular thyroid cancer and breast cancer by binding to the PI3K regulatory subunit p85⍺. However, the role of TRβ in suppressing PI3K signaling in ATC is not completely delineated. Here we report that TRβ indeed suppresses PI3K signaling in ATC cell lines through unreported genomic mechanisms including a decrease in RTK expression and increase in phosphoinositide and Akt phosphatase expression. Furthermore, the reintroduction and activation of TRβ in ATC cell lines enables an increase in the efficacy of the competitive PI3K inhibitors LY294002 and buparlisib on cell viability, migration, and suppression of PI3K signaling. These findings not only uncover additional tumor suppressor mechanisms of TRβ but shed light into the implication of TRβ status and activation on inhibitor efficacy in ATC tumors.

scholarly journals Thyroid hormone receptor β mutations in the ‘hot-spot region’ are rare events in thyroid carcinomas

2007 ◽  
Vol 192 (1) ◽  
pp. 83-86 ◽  
Author(s):  
Ana Sofia Rocha ◽  
Ricardo Marques ◽  
Inês Bento ◽  
Ricardo Soares ◽  
João Magalhães ◽  
...  
Keyword(s):  
Thyroid Cancer ◽  
Thyroid Hormone ◽  
Transgenic Mice ◽  
Cell Lines ◽  
Hormone Receptor ◽  
Thyroid Hormone Receptor ◽  
Hot Spot ◽  
Direct Sequencing ◽  
Human Thyroid ◽  
Thyroid Hormone Receptor Β

Thyroid cancer constitutes the most frequent endocrine neoplasia. Targeted expression of rearranged during transfection (RET)/papillary thyroid carcinoma (PTC) and V600E V-raf murine sarcoma viral oncogene homolog B1 (BRAF) to the thyroid glands of transgenic mice results in tumours similar to those of human PTC, providing evidence for the involvement of these oncogenes in PTC. Kato et al. developed a mouse model that mimics the full spectrum of the human follicular form of thyroid cancer (FTC). FTC rapidly develops in these mice through introduction of the thyroid hormone receptor β (THRB)PV mutant on the background of the inactivated THRB wt locus. Our aim was to verify if, in the context of human follicular thyroid carcinogenesis, THRB acted as a tumour suppressor gene. We screened for mutations of the THRB gene in the hot-spot region, spanning exons 7–10, in 51 thyroid tumours and six thyroid cancer cell lines by PCR and direct sequencing. We did not find mutations in any of the tumours or cell lines analysed. Our findings suggest that, in contrast to the findings on the THRB-mutant transgenic mice, THRB gene mutations are not a relevant mechanism for human thyroid carcinogenesis.

scholarly journals Lack of Mutations in the Thyroid Hormone Receptor (TR) α and β Genes but Frequent Hypermethylation of the TRβ Gene in Differentiated Thyroid Tumors

2007 ◽  
Vol 92 (12) ◽  
pp. 4766-4770 ◽  
Author(s):  
Biju Joseph ◽  
Meiju Ji ◽  
Dingxie Liu ◽  
Peng Hou ◽  
Mingzhao Xing
Keyword(s):  
Thyroid Cancer ◽  
Thyroid Hormone ◽  
Tumor Cell ◽  
Gene Mutation ◽  
Hormone Receptor ◽  
Thyroid Hormone Receptor ◽  
Thyroid Tumor ◽  
Thyroid Tumors ◽  
Tumor Cell Lines ◽  
Thyroid Adenomas

Abstract Context: It remains inconclusive whether mutations in thyroid hormone receptor (TR) genes naturally occur in thyroid cancer and whether these genes could be suppressors of this cancer. Objectives: Our objectives were to examine further mutations of TRα and TRβ genes in thyroid cancer and also to examine their methylation as an epigenetic silencing mechanism in thyroid cancer. Experimental Design: Instead of using a cDNA sequencing approach used in previous studies, we used genomic DNA to sequence directly the coding regions of the TRα and TRβ genes to search mutations in various differentiated thyroid tumors and used methylation-specific PCR to analyze promoter methylation of these genes. Allelic zygosity status at TRβ was also analyzed. Results: We found no TRα gene mutation in 17 papillary thyroid cancers (PTCs) and 11 follicular thyroid cancers (FTCs), and no TRβ gene mutation in 16 PTCs and 12 FTCs. We also found no methylation of the TRα gene in 33 PTCs, 31 FTCs, 20 follicular thyroid adenomas (FTAs), and 10 thyroid tumor cell lines. In contrast, we found hypermethylation of the TRβ gene in 10 of 29 (34%) PTCs, 22 of 27 (81%) FTCs, five of 20 (25%) follicular thyroid adenomas, and three of 10 (30%) thyroid tumor cell lines, with the highest prevalence in FTC. We additionally examined loss of heterozygosity at TRβ and found it in three of nine (33%) PTCs and three of nine (33%) FTCs. Conclusions: Mutation is not common in TR genes, whereas hypermethylation of the TRβ gene as an alternative gene silencing mechanism is highly prevalent in thyroid cancer, particularly FTC, consistent with a possible tumor suppressor role of this gene for FTC.

scholarly journals Overexpression of thyroid hormone receptor beta1 is associated with thyrotropin receptor gene expression and proliferation in a human thyroid carcinoma cell line

2000 ◽  
Vol 165 (2) ◽  
pp. 379-389 ◽  
Author(s):  
ST Chen ◽  
HY Shieh ◽  
JD Lin ◽  
KS Chang ◽  
KH Lin
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Thyroid Hormone ◽  
Cell Line ◽  
Cell Lines ◽  
Hormone Receptor ◽  
Thyroid Hormone Receptor ◽  
Human Thyroid ◽  
Thyrotropin Receptor ◽  
Tshr Gene

To correlate the differentiation phenotype of two human thyroid cancer cell lines with their expression of various molecular markers, we analyzed the mRNA levels of four thyroid-specific genes, including thyrotropin receptor (TSHR), thyroglobulin (Tg), thyroid transcription factor-1 (TTF-1), and paired-box containing transcription factor-8 (PAX-8) genes. The results showed a differentiation-status-related pattern in which a well-differentiated cell line (WRO) expressed all the four genes, in contrast to an anaplastic cell line (ARO) that expressed TTF-1 and reduced levels of TSHR, but no Tg or PAX-8 genes. Furthermore, to verify the finding of concomitant loss of beta subtype thyroid hormone receptor (TRbeta) and TSHR gene expression in neoplastic thyroid tumors (Bronnegard et al. 1994), we examined the expression levels of TRbeta1 gene in these cell lines. Whereas the WRO cells produced an abundant amount of TRbeta1 protein detectable by immunoprecipitation, the ARO cells produced none. This new observation prompted us to investigate whether overexpression of TRbeta1 protein in ARO cells might produce changes in the differentiation phenotypes. We found that the level of expression of the TSHR gene and the proliferative index of ARO cells were significantly upregulated in the cells stably transfected with wild-type TRbeta1. These findings suggest that TRbeta1 protein overexpression can affect the differentiation phenotypes and induce more efficient cell proliferation of the anaplastic ARO cells.

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