Thyrocyte-specific deletion of insulin and IGF-1 receptors induces papillary thyroid carcinoma-like lesions through EGFR pathway activation

STR mutations on chromosome 15q cause thyrotropin resistance by activating a primate-specific enhancer of MIR7-2/MIR1179

Thyrotropin (TSH) is the master regulator of thyroid gland growth and function. Resistance to TSH (RTSH) describes conditions with reduced sensitivity to TSH. Dominantly inherited RTSH has been linked to a locus on chromosome 15q, but its genetic basis has remained elusive. Here we show that non-coding mutations in a (TTTG)4 short tandem repeat (STR) underlie dominantly inherited RTSH in all 82 affected participants from 12 unrelated families. The STR is contained in a primate-specific Alu retrotransposon with thyroid-specific cis-regulatory chromatin features. Fiber-seq and RNA-seq studies revealed that the mutant STR activates a thyroid-specific enhancer cluster, leading to haplotype-specific upregulation of the bicistronic MIR7-2/MIR1179 locus 35 kb downstream and overexpression of its microRNA products in the participants' thyrocytes. An imbalance in signaling pathways targeted by these micro-RNAs provides a working model for this cause of RTSH. This finding broadens our current knowledge of genetic defects altering pituitary-thyroid feedback regulation.

Risk of thyroid cancer associated with glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors in patients with type 2 diabetes: A population-based cohort study

AIMS

To determine the potential association between the use of either glucagon-like peptide-1 receptor agonists (GLP-1RAs) or dipeptidyl peptidase-4 (DPP-4) inhibitors, and the risk of thyroid cancer in individuals with type 2 diabetes.

MATERIALS AND METHODS

This population-based cohort study used claims data from the Korean National Health Insurance Database, 2014-2020. Two distinct cohorts were established to compare each incretin-based drug with sodium-glucose cotransporter-2 (SGLT2) inhibitors, chosen as active comparators because of their previous non-association with thyroid cancer, and their common usage as add-on therapy to metformin along with GLP-1RAs and DPP-4 inhibitors. The first cohort included 21 722 new users of GLP-1RAs and 326 993 new users of SGLT2 inhibitors, whereas the second cohort included 904 300 DPP-4 inhibitor new users and 112 017 SGLT2 inhibitor new users. The outcome was the time to incident thyroid cancer. Weighted Cox proportional models were used to estimate hazard ratios of thyroid cancer incidence associated with incretin-based drugs of interest.

RESULTS

The use of GLP-1RAs was not associated with an increased risk of thyroid cancer (weighted hazard ratio 0.98, 95% confidence interval 0.62-1.53) compared with that of SGLT2 inhibitors. Using DPP-4 inhibitors was also not associated with an increased risk of thyroid cancer (0.95, 0.79-1.14) compared with that of SGLT2 inhibitors. No significant effect modifications were observed across subgroup analyses. Sensitivity analyses, including alternative outcome definition analysis of medullary thyroid cancer, were consistent with the primary analysis results.

CONCLUSIONS

GLP-1RAs and DPP-4 inhibitors were not associated with an increased risk of thyroid cancer in individuals with type 2 diabetes.

Transplantable human thyroid organoids generated from embryonic stem cells to rescue hypothyroidism

The thyroid gland captures iodide in order to synthesize hormones that act on almost all tissues and are essential for normal growth and metabolism. Low plasma levels of thyroid hormones lead to hypothyroidism, which is one of the most common disorder in humans and is not always satisfactorily treated by lifelong hormone replacement. Therefore, in addition to the lack of in vitro tractable models to study human thyroid development, differentiation and maturation, functional human thyroid organoids could pave the way to explore new therapeutic approaches. Here we report the generation of transplantable thyroid organoids derived from human embryonic stem cells capable of restoring plasma thyroid hormone in athyreotic mice as a proof of concept for future therapeutic development.

EGFR/MET promotes hepatocellular carcinoma metastasis by stabilizing tumor cells and resisting to RTKs inhibitors in circulating tumor microemboli

The receptor tyrosine kinases (RTKs) family is well-recognized as vital targets for the treatment of hepatocarcinoma cancer (HCC) clinically, whereas the survival benefit of target therapy sorafenib is not satisfactory for liver cancer patients due to metastasis. EGFR and MET are two molecules of the RTK family that were related to the survival time of liver cancer patients and resistance to targeted therapy in clinical reports. However, the mechanism and clinical therapeutic value of EGFR/MET in HCC metastasis are still not completely clarified. The study confirmed that EGFR/MET was highly expressed in HCC cells and tissues and the phosphorylation was stable after metastasis. The expression of EGFR/MET was up-regulated in circulating tumor microemboli (CTM) to accelerate IL-8 production and resistance to the lethal effect of leukocytes. Meanwhile, highly expressed EGFR/MET effectively regulated the Ras/MAPK pathway and stabilized suspended HCC cells by facilitating proliferation and inhibiting apoptosis. Moreover, EGFR/MET promoted phosphorylation of hetero-RTKs, which was dependent on high-energy phosphoric acid compounds rather than their direct interactions. In conclusion, highly expressed EGFR/MET could be used in CTM identification and suitable for preventing metastasis of HCC in clinical practice.

Potential Novel Modules and Hub Genes as Prognostic Candidates of Thyroid Cancer by Weighted Gene Co-Expression Network Analysis

Background

Although thyroid cancer (THCA) is one of the most common type of endocrine malignancy, its highly complex molecular mechanisms of carcinogenesis are not completely known.

Materials and Methods

In this study, weighted gene co-expression network analysis (WGCNA) was utilized to construct gene co-expression networks and evaluate the relations between modules and clinical traits to identify potential prognostic biomarkers for THCA patients. RNA-seq data and clinical data were downloaded from The Cancer Genome Atlas (TCGA). Other independent datasets from the Gene Expression Omnibus (GEO) database and the Human Protein Atlas database were performed to validate findings.

Results

Finally, 11 co-expression modules were constructed and four hub genes, CCDC146, SLC4A4, TDRD9 and MUM1L1, were identified and validated statistically, which were considerably interrelated to worse survival of THCA patients.

Conclusion

This research study revealed four hub genes may be considered candidate prognostic biomarkers and potential therapeutic targets for THCA patients in the future.

Insulin-Like Growth Factor Pathway and the Thyroid

The insulin-like growth factor (IGF) pathway comprises two activating ligands (IGF-I and IGF-II), two cell-surface receptors (IGF-IR and IGF-IIR), six IGF binding proteins (IGFBP) and nine IGFBP related proteins. IGF-I and the IGF-IR share substantial structural and functional similarities to those of insulin and its receptor. IGF-I plays important regulatory roles in the development, growth, and function of many human tissues. Its pathway intersects with those mediating the actions of many cytokines, growth factors and hormones. Among these, IGFs impact the thyroid and the hormones that it generates. Further, thyroid hormones and thyrotropin (TSH) can influence the biological effects of growth hormone and IGF-I on target tissues. The consequences of this two-way interplay can be far-reaching on many metabolic and immunologic processes. Specifically, IGF-I supports normal function, volume and hormone synthesis of the thyroid gland. Some of these effects are mediated through enhancement of sensitivity to the actions of TSH while others may be independent of pituitary function. IGF-I also participates in pathological conditions of the thyroid, including benign enlargement and tumorigenesis, such as those occurring in acromegaly. With regard to Graves' disease (GD) and the periocular process frequently associated with it, namely thyroid-associated ophthalmopathy (TAO), IGF-IR has been found overexpressed in orbital connective tissues, T and B cells in GD and TAO. Autoantibodies of the IgG class are generated in patients with GD that bind to IGF-IR and initiate the signaling from the TSHR/IGF-IR physical and functional protein complex. Further, inhibition of IGF-IR with monoclonal antibody inhibitors can attenuate signaling from either TSHR or IGF-IR. Based on those findings, the development of teprotumumab, a β-arrestin biased agonist as a therapeutic has resulted in the first medication approved by the US FDA for the treatment of TAO. Teprotumumab is now in wide clinical use in North America.

Transcription factor GLIS3: Critical roles in thyroid hormone biosynthesis, hypothyroidism, pancreatic beta cells and diabetes

GLI-Similar 3 (GLIS3) is a member of the GLIS subfamily of Krüppel-like zinc finger transcription factors that functions as an activator or repressor of gene expression. Study of GLIS3-deficiency in mice and humans revealed that GLIS3 plays a critical role in the regulation of several biological processes and is implicated in the development of various diseases, including hypothyroidism and diabetes. This was supported by genome-wide association studies that identified significant associations of common variants in GLIS3 with increased risk of these pathologies. To obtain insights into the causal mechanisms underlying these diseases, it is imperative to understand the mechanisms by which this protein regulates the development of these pathologies. Recent studies of genes regulated by GLIS3 led to the identification of a number of target genes and have provided important molecular insights by which GLIS3 controls cellular processes. These studies revealed that GLIS3 is essential for thyroid hormone biosynthesis and identified a critical function for GLIS3 in the generation of pancreatic β cells and insulin gene transcription. These observations raised the possibility that the GLIS3 signaling pathway might provide a potential therapeutic target in the management of diabetes, hypothyroidism, and other diseases. To develop such strategies, it will be critical to understand the upstream signaling pathways that regulate the activity, expression and function of GLIS3. Here, we review the recent progress on the molecular mechanisms by which GLIS3 controls key functions in thyroid follicular and pancreatic β cells and how this causally relates to the development of hypothyroidism and diabetes.

Identification of gene co-expression modules and hub genes associated with lymph node metastasis of papillary thyroid cancer

Papillary thyroid cancer (PTC) is the most prevalent histological type among thyroid cancers, and some patients are at a high risk for recurrent disease or even death. Identification for the potential biomarkers of PTC may contribute to early discovery of recurrence and treatment. In The Cancer Genome Atlas (TCGA) database, we obtained the information of RNA sequence data and clinical characteristics of PTC. Weighted gene co-expression network analysis (WGCNA) was performed to construct gene co-expression networks and investigate the relationship between modules and clinical traits. Finally, we constructed 16 co-expression modules in 10,428 genes, and three key modules (darkturquoise, lightyellow, and red) associated with tumor N grade were identified. The results of functional annotation indicated that the darkturquoise module was primarily enriched in the regulation of the extracellular matrix (ECM), collagen metabolism, and cell adhesion, the lightyellow module was primarily enriched in the mitochondrial function regulation and energy synthesis, and the red module was primarily enriched in the process of cell junction, apoptosis, and inflammatory response, suggesting their significant role in the progression of PTC. In addition, the hub genes in the three modules were identified and screened for differentially expressed genes (DEGs). Relapse-free survival analyses found that 11 genes (KCNQ3, MET, FN1, ITGA3, RUNX1, ITGA2, PERP, GCSH, FAAH, NGFRAP1, and HSPA5) may play a pivotal role in PTC relapse. In general, our research revealed the key co-expression modules and identified several prognostic biomarkers, which provides some new insights into the lymph node metastasis of PTC.