Expression of activator protein-1 in papillary thyroid carcinoma and its clinical significance

Loss of thyroid gland circadian PER2 rhythmicity in aged mice and its potential association with thyroid cancer development

Molecular clocks operate in peripheral tissues, including endocrine glands, and play important regulatory roles in this context. However, potential age-related changes in the expression rhythmicity of clock genes and the effects of these changes on the thyroid gland remain unknown. In the present study, we evaluated the expression rhythmicity of peripheral thyroid clock genes in aged mice using RNA-seq transcriptomic analysis in young (3.5-month) versus aged (20-month) mice. In addition, we determined the cellular effects of silencing of PER2, a major clock gene regulator, in human thyroid cell lines. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that differentially expressed genes (DEGs) in the thyroid glands of aged mice were involved in mitogen-activated protein kinase (MAPK) signaling, chemokine signaling, circadian entrainment, PI3K/AKT signaling, and Apelin signaling. The expression of circadian clock genes Arntl/Bmal1 was significantly downregulated in thyroid glands of aged mice, whereas the expression of genes involved in regulation of cell proliferation, migration, and tumorigenesis was upregulated. Peripheral thyroid clock genes, particularly Per mRNA and PER2 protein, were downregulated in the thyroid glands of aged mice, and circadian oscillation of these genes was declined. Knockdown of the circadian clock gene PER2 in human thyroid follicular cells induced AP-1 activity via JNK MAPK signaling activation, which increased cell proliferation. Furthermore, the aging-related loss of PER2 circadian oscillation activated the AP-1 transcription factor via the JNK MAPK pathway, which could contribute to thyroid hyperplasia, a common age-related condition.

Predictive Significance of Two MMP-9 Promoter Polymorphisms and Acetylated c-Jun Transcription Factor for Papillary Thyroid Carcinoma Advancement

Papillary thyroid carcinoma represents a challenge from a prognostic standpoint. Molecular alterations responsible for PTC advancement include MMP-9 genetic promoter polymorphisms that bind transcription factors with varying degrees of affinity and, hence, constitute a predisposition for MMP-9 expression. We examined how two promoter polymorphisms (the -1562 C/T transition and -131 (CA)n tandem repeats) as well as levels of the c-Jun transcription factor and its modified form acetylated at Lys271 influence MMP-9 expression and PTC progression. A significant proportion of PTC samples were heterozygous for the (CA)n tandem repeat number, had a transcription-promoting T allele at -1562, and expressed high levels of c-Jun, acetylated c-Jun, and MMP-9 protein. The T allele at the -1562 position accompanied the elevated MMP-9 protein expression, while high acetylated c-Jun levels accompanied the high MMP-9 protein levels on mRNA. The -1562 C/T transition, MMP-9, and acetylated c-Jun were associated with the presence of extra-thyroid invasion and degree of tumor infiltration, while the T allele and acetylated c-Jun also correlated with tumor stage. We conclude that the -1562 MMP-9 polymorphism and levels of acetylated c-Jun affect PTC progression via modulation of MMP-9 levels. Genotyping the MMP-9 at -1562 and estimating the levels of MMP-9 and acetylated c-Jun in PTC may prove beneficial in identifying high-risk patients.

Predicting factors of central lymph node metastasis and BRAFV600E mutation in Chinese population with papillary thyroid carcinoma

Objective

The aim of this study was to evaluate the predictive factors of central lymph node metastasis (CLNM) and BRAF^V600E mutation in Chinese patients with papillary thyroid carcinoma (PTC).

Methods

A total of 943 PTC patients who underwent thyroidectomy from 2014 to 2016 at our hospital were enrolled. Those patients were divided into PTC > 10 mm and papillary thyroid microcarcinoma (PTMC) groups by tumor size. The BRAF^V600E mutation was examined by quantitative real-time PCR. Univariate and multivariate analyses were used to examine risk factors associated with CLNM and the BRAF^V600E mutation.

Results

The frequency of CLNM was 53% (505/943). Both univariate and multivariate analyses suggested that the risk factors for CLNM in PTC patients were male, younger age, and larger tumor size (P < 0.05). Coexistent Hashimoto thyroiditis (HT) was an independent protective factor against CLNM when the tumor was > 10 mm (P = 0.006). Stratified analysis revealed that male, age ≤ 30 years, and tumor size > 5 mm were independent risk factors for CLNM. The BRAF^V600E mutation rate was 85%. Multivariate logistic regression analysis revealed that age (P < 0.001) and coexistent HT (P = 0.005) were independent predictive factors of BRAF^V600E mutation in PTC patients. Only age was a risk factor for the BRAF^V600E mutation when the tumor was > 10 mm (P = 0.004). In the PTMC group, the BRAF^V600E mutation was significantly correlated with tumor size (P < 0.001) and coexistent HT (P = 0.03). Stratified analysis revealed that age > 30 years and tumor size > 5 mm were independent predictive factors of BRAF^V600E mutation. Furthermore, the incidence of CLNM was significantly higher in BRAF^V600E mutation-positive patients (P = 0.009) when the tumor was ≤ 5 mm.

Conclusion

The factors male, younger age (≤ 30 years), large tumor size (> 5 mm), and coexistent HT are independent predicative factors for CLNM. The BRAF^V600E mutation is associated with both large size and without HT in PTMC patients, age > 30 years in the PTC > 10 mm group. The BRAF^V600E mutation was an independent risk factor for CLNM when the tumor was ≤ 5 mm. For optimal management, these features should be comprehensively evaluated to determine the initial surgical approach for PTC patients.

The mechanisms of celastrol in treating papillary thyroid carcinoma based on network pharmacology and experiment verification

Background

Celastrol, a triterpene present in the traditional Chinese medicine (TCM) Triptergium wilfordii, has been demonstrated to have remarkable anticancer activity. However, its specific mechanism on papillary thyroid carcinoma (PTC) remains to be elucidated.

Methods

Potential targets of celastrol were screened from public databases. Through the Gene Expression Omnibus (GEO) online database, we obtained the bioinformatics analysis profile of PTC, GSE33630, and analyzed the differentially expressed genes (DEGs). Then, a protein-protein interaction (PPI) network was constructed by utilizing the STRING database. Furthermore, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were conducted. Finally, drug interactions between hub genes and celastrol were verified by molecular docking.

Results

Four core nodes (MMP9, JUN, ICAM1, and VCAM1) were discerned via constructing a PPI network of 47 common targets. Through functional enrichment analysis, it was confirmed that the above target genes were basically enriched in the interleukin-17 (IL-17), nuclear factor kappa-B (NF-κB), and tumor necrosis factor (TNF) signaling pathways, which are involved in the inflammatory microenvironment to inhibit the development and progression of tumors. Molecular docking results demonstrated that celastrol has a strong binding efficiency with the 4 key proteins.

Conclusions

In this research, it was demonstrated that celastrol can regulate a variety of proteins and signaling pathways against PTC, providing a theoretical basis for future clinical applications.

TFAP2B, AP-1 and JAZF1 Expression in Tissues of Papillary Thyroid Carcinoma Patients; Clinical, Pathological and Prognostic Values

OBJECTIVE

Transcription factor activating protein 2 B (TFAP2 B) is a transcription factor that regulates many steps of embryogenesis, cell growth, apoptosis and recently oncogenesis and cancer progression. AP-1 is a transcription factor that is a downstream molecule of the MAPK signaling pathway. Juxtaposed with zinc finger gene 1 (JAZF1) is a recently detected transforming growth factor which has a role in carcinogenesis. Hence the present study aimed to assess those markers expression in tissues from patients with such cancer correlation their expression with clinic-pathological findings of the tumor and prognostic and follow-up findings of patients.

METHODS

We have collected tissue samples from papillary thyroid cancer patients and adjacent non-neoplastic tissues from 80 patients. We assessed the expression of TFAP2B, AP-1 and JAZF1 using immunohistochemistry.

RESULTS

Expression of TFAP2B was positively associated with lymph nodes metastases (p=0.003), distant metastases (p=0.002), recurrence of the tumor (p=0.002), unfavourable disease-free survival rate (p=0.003). AP-1 expression is positively associated with advanced stage (p=0.002), presence of extra-thyroid invasion (p=0.005), recurrence of the tumor (p=0.005), unfavorable disease-free survival rate (p=0.01). JAZF1 expression is negatively associated with huge tumor size (0.023), vascular invasion (p=0.007) and unfavorable overall survival rate (p=.030).

CONCLUSION

High expression levels of TFAP2B and AP-1 and low expression levels of JAZF1 were associated with unfavourable pathological, prognostic parameters and dismal patient's outcome.<br />.

Telomerase and Telomeres Biology in Thyroid Cancer

Telomere and telomerase regulation contributes to the onset and evolution of several tumors, including highly aggressive thyroid cancers (TCs). TCs are the most common endocrine malignancies and are generally characterized by a high rate of curability. However, a small but significant percentage develops distant metastasis or progresses into undifferentiated forms associated with bad prognosis and for which poor therapeutic options are available. Mutations in telomerase reverse transcriptase (TERT) promoter are among the most credited prognostic marker of aggressiveness in TCs. Indeed, their frequency progressively increases passing from indolent lesions to aggressive and anaplastic forms. TERT promoter mutations create binding sites for transcription factors, increasing TERT expression and telomerase activity. Furthermore, aggressiveness of TCs is associated with TERT locus amplification. These data encourage investigating telomerase regulating pathways as relevant drivers of TC development and progression to foster the identification of new therapeutics targets. Here, we summarize the current knowledge about telomere regulation and TCs, exploring both canonical and less conventional pathways. We discuss the possible role of telomere homeostasis in mediating response to cancer therapies and the possibility of using epigenetic drugs to re-evaluate the use of telomerase inhibitors. Combined treatments could be of support to currently used therapies still presenting weaknesses.