Meta-analysis of promoter methylation in eight tumor-suppressor genes and its association with the risk of thyroid cancer

CTC, ctDNA, and Exosome in Thyroid Cancers: A Review

Thyroid cancer has become more common in recent years all around the world. Many issues still need to be urgently addressed in the diagnosis, treatment, and prognosis of thyroid cancer. Liquid biopsy (mainly circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), and circulating exosomes) may provide a novel and ideal approach to solve these issues, allows us to assess the features of diseases more comprehensively, and has a function in a variety of malignancies. Recently, liquid biopsy has been shown to be critical in thyroid cancer diagnosis, treatment, and prognosis in numerous previous studies. In this review, by testing CTCs, ctDNA, and exosomes, we focus on the possible clinical role of liquid biopsy in thyroid cancer, including diagnostic and prognostic biomarkers and response to therapy. We briefly review how liquid biopsy components have progressed in thyroid cancer by consulting the existing public information. We also discuss the clinical potential of liquid biopsy in thyroid cancer and provide a reference for liquid biopsy research. Liquid biopsy has the potential to be a useful tool in the early detection, monitoring, or prediction of response to therapies and prognosis in thyroid cancer, with promising clinical applications.

Transcriptomic landscape of TIMP3 oncosuppressor activity in thyroid carcinoma

BACKGROUND

Papillary thyroid cancer (PTC) is the most frequent thyroid tumor. The tissue inhibitor of metalloproteinase-3 (TIMP3) gene encodes a matrix metalloproteinases inhibitor that exerts a tumor suppressor role in several tumor types. TIMP3 is frequently downregulated in PTC by promoter methylation. We have previously functionally demonstrated that TIMP3 exerts an oncosuppressor role in PTC: TIMP3 restoration in the PTC-derived NIM1 cell line affects in vitro migration, invasion and adhesive capability, while reduces tumor growth, angiogenesis and macrophage recruitment in vivo. To get a deeper insight on the mediators of TIMP3 oncosuppressor activity in thyroid tumors, here we focused on the TIMP3 related transcriptome.

METHODS

TCGA database was used for investigating the genes differentially expressed in PTC samples with low and high TIMP3 expression. Genome wide expression analysis of clones NIM1-T23 (expressing a high level of TIMP3 protein) and NIM1-EV (control empty vector) was performed. Gene sets and functional enrichment analysis with clusterProfiler were applied to identify the modulated biological processes and pathways. CIBERSORT was used to evaluate the distribution of different immunological cell types in TCGA-PTC tumor samples with different TIMP3 expression levels. Real time PCR was performed for the validation of selected genes.

RESULTS

Thyroid tumors with TIMP3-high expression showed a down-modulation of inflammation-related gene sets, along with a reduced protumoral hematopoietic cells fraction; an enrichment of cell adhesion functions was also identified. Similar results were obtained in the TIMP3-overexpessing NIM1 cells in vitro model, where a down-regulation of immune-related function gene sets, some of which also identified in tumor samples, was observed. Interestingly, through enrichment analysis, were also recognized terms related to cell adhesion, extracellular matrix organization, blood vessel maintenance and vascular process functions that have been found modulated in our previous in vitro and in vivo functional studies.

CONCLUSIONS

Our results highlight the correlation of TIMP3 expression levels with the regulation of inflammatory functions and the immune infiltration composition associated with different PTC prognosis, thus providing a broader view on the oncosuppressor role of TIMP3 in PTC.

BI-847325, a selective dual MEK and Aurora kinases inhibitor, reduces aggressive behavior of anaplastic thyroid carcinoma on an in vitro three-dimensional culture

BACKGROUND

Anaplastic thyroid carcinoma (ATC) is the most aggressive subtype of thyroid cancer. In this study, we used a three-dimensional in vitro system to evaluate the effect of a dual MEK/Aurora kinase inhibitor, BI-847325 anticancer drug, on several cellular and molecular processes involved in cancer progression.

METHODS

Human ATC cell lines, C643 and SW1736, were grown in alginate hydrogel and treated with IC₅₀ values of BI-847325. The effect of BI-847325 on inhibition of kinases function of MEK1/2 and Aurora kinase B (AURKB) was evaluated via Western blot analysis of phospho-ERK1/2 and phospho-Histone H3 levels. Sodium/iodide symporter (NIS) and thyroglobulin (Tg), as two thyroid-specific differentiation markers, were measured by qRT-PCR as well as flow cytometry and immunoradiometric assay. Apoptosis was assessed by Annexin V/PI flow cytometry and BIM, NFκB1, and NFκB2 expressions. Cell cycle distribution and proliferation were determined via P16, AURKA, and AURKB expressions as well as PI and CFSE flow cytometry assays. Multidrug resistance was evaluated by examining the expression of MDR1 and MRP1. Angiogenesis and invasion were investigated by VEGF expression and F-actin labeling with Alexa Fluor 549 Phalloidin.

RESULTS

Western blot results showed that BI-847325 inhibits MEK1/2 and AURKB functions by decreasing phospho-ERK1/2 and phospho-Histone H3 levels. BI-847325 induced thyroid differentiation markers and apoptosis in ATC cell lines. Inversely, BI-847325 intervention decreased multidrug resistance, cell cycle progression, proliferation, angiogenesis, and invasion at the molecular and/or cellular levels.

CONCLUSION

The results of the present study suggest that BI-857,325 might be an effective multi-targeted anticancer drug for ATC treatment.

Epigenetic modification and BRAF gene mutation in thyroid carcinoma

Thyroid cancer remains the most prevailing endocrine malignancy, and a progressively increasing incidence rate has been observed in recent years, with 95% of thyroid cancer represented by differentiated thyroid carcinomas. The genetics and epigenetics of thyroid cancer are gradually increasing, and gene mutations and methylation changes play an important roles in its occurrence and development. Although the role of RAS and BRAF mutations in thyroid cancer have been partially clarified,but the pathogenesis and molecular mechanisms of thyroid cancer remain to be elucidated. Epigenetic modification refer to genetic modification that does not change the DNA sequence of a gene but causes heritable phenotypic changes in its expression. Epigenetic modification mainly includes four aspects: DNA methylation, chromatin remodelling, noncoding RNA regulation, and histone modification. This article reviews the importance of thyroid cancer epigenetic modification and BRAF gene mutation in the treatment of thyroid cancer.

Role of GATA3 in tumor diagnosis: A review

GATA binding protein 3 (GATA3) belongs to a family of transcription factors comprising six members. These proteins identify G-A-T-A containing sequences in the target gene and bind to DNA target via two zinc-finger domains. The aim of this study was to evaluate the role of GATA3 in the diagnosis of tumors and its value as a prognostic marker. To perform this review, a comprehensive search was conducted through PubMed, Embase, Scopus, Cochrane and Google Scholar databases from 1985 to 2020. Articles were considered thoroughly by independent reviewers and data were extracted in predefined forms. Final synthesis was conducted by using appropriate data from included articles in each topic. Studies have shown that GATA3 has a critical role in the development of epithelial structures in both embryonic and adult tissues. The majority of studies regarding GATA3 expression in tumor evaluation focused on breast and urothelial neoplasms, whether primary or metastatic. Its sensitivity in these neoplasms has been reported to be high and made this marker more valuable than other available immunohistochemistry markers. However, GATA3 expression was not restricted to these tumors. Studies have shown that GATA3 immunostaining could be a useful tool in various tumors in kidney, salivary gland, endocrine system, hematopoietic system, and skin. GATA3 can also be used as a useful prognostic tool. Although GATA3 is a multi-specific immunohistochemical stain, it is a valuable marker in the panel for confirming many epithelial or mesenchymal neoplasms as both a diagnostic and prognostic tool.

DAPK2 activates NF-κB through autophagy-dependent degradation of I-κBα during thyroid cancer development and progression

Background

Death-associated protein kinase 2 (DAPK2) is a serine/threonine kinase, which has been implicated in autophagy and apoptosis. DAPK2 functions as a tumor suppressor in various cancers. However, the role of DAPK2 in thyroid cancer (TC) is unclear.

Methods

RNA sequencing of human TC samples was performed to identify differentially expressed genes that may play a role in TC development. The messenger RNA (mRNA) expression of DAPK2 was verified by quantitative real-time polymerase chain reaction (qRT-PCR). To investigate the role of DAPK2 in TC development, DAPK2 was knocked down and overexpressed in a TTA1 cell line. The effect of DAPK2 on cell proliferation, sensitization of TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis and tumor growth was examined. The effect of DAPK2 on autophagy and NF-κB activation was investigated to address the underlying mechanism.

Results

DAPK2 was upregulated in TC. Knockdown of DAPK2 in TTA1 cells led to reduced cell proliferation, sensitization of TRAIL-induced apoptosis, and restricted tumor growth both in vitro and in vivo, while overexpression of DAPK2 exhibited the opposite effect. Mechanistically, DAPK2 promoted autophagy as demonstrated by the accumulation of microtubule-associated protein 1A/1B-light chain 3 (LC3)-II, which correlated with the level of nuclear factor-κB (NF-κB) activation. Knockdown of inhibitory-κBα (I-κBα) in short hairpin (sh) DAPK2 TTA1 cells restored the activity of NF-κB, suggesting DAPK2 activated NF-κB through autophagy-mediated I-κBα degradation.

Conclusions

Our findings revealed a pivotal role of DAPK2 in thyroid carcinogenesis, being required for tumor growth and for resistance to TRAIL-induced apoptosis through autophagy-mediated I-κBα degradation. This result provides a novel target for the therapy of TC.

RAP1GAP Functions as a Tumor Suppressor Gene and Is Regulated by DNA Methylation in Differentiated Thyroid Cancer

Inactivation of tumor suppressor genes, such as RAP1GAP, by hypermethylation of their regulatory region can give rise to thyroid tumors. The aim of this study was to investigate the expression of the RAP1GAP gene and the DNA methylation patterns of its CpG74a, CpG74b, and CpG24 in an Iranian population with differentiated thyroid cancer (DTC). In this study, 160 individuals who underwent thyroidectomy in the Tehran Erfan Hospital between 2018 and 2020 were selected. DNA methylation patterns of selected CpG islands (CpG74a, CpG74b, and CpG24) were determined using methylation-specific PCR. The mRNA expression and protein level of -RAP1GAP were also evaluated. SW1736 and B-CPAP cells were treated with 5-aza-2'-deoxycytidine (5-Aza) to demethylate these regions. The hypermethylation rates of CpG74a and CpG24 in DTC samples were significantly higher than in the control. The mRNA expression and protein level of -RAP1GAP were significantly decreased in the DTC group. In the DTC group, hypermethylation in CpG74a was correlated with decreasing RAP1GAP expression (R2: 0.34; p = 0.043). CpG74a with a specificity of 86.4% has significant prediction power to distinguish between DTC and normal thyroid tissues. Additionally, hypermethylation of CpG74a was significantly associated with higher tumor stages (stage III-IV: 77%; stage I-II: 23%; p = 0.012). Increasing expression of RAP1GAP after demethylation with 15 µM of 5-Aza was observed in both cell lines. These results indicate that DNA hypermethylation in CpG74a can be considered as an epigenetic biomarker in DTC.

Endocrinology and Metabolism Research Institute from inception to maturity: an overview of 25-year activity

Endocrinology and Metabolism Research Institute (EMRI) was founded in 1993. EMRI progressed step by step from inception and reached to its maturation during the past 25 years. EMRI has expanded and progressed in different aspects including human resources and infrastructures (laboratories and new technologies) and has obtained the first rank in the country in endocrinology research. It has also collaborated with regional and international organizations such as World Health Organization (WHO), International Osteoporosis Foundation (IOF), and American Association of Clinical Endocrinologists (AACE). This article provides an overview of EMRI activities during a quarter of a century.

NOL4 is Downregulated and Hyper-Methylated in Papillary Thyroid Carcinoma Suggesting Its Role as a Tumor Suppressor Gene

BACKGROUND

Thyroid cancer is the fourth most common cancer in the world. Papillary thyroid carcinoma (PTC) accounts for 80% of all types of thyroid neoplasm. Epigenetic alterations such as DNA methylation are known as the main cause of different types of cancers through inactivation of tumor suppressor genes.

OBJECTIVES

In the present study, the expression and methylation of suggested gene namely nucleolar protein 4 (NOL4) in PTC in comparison to multi nodular goiter (MNG) have been studied.

METHODS

Forty-one patients with PTC and 38 patients affected by MNG were recruited. Thyroid tissues were obtained during thyroidectomy. RNA and DNA were extracted from thyroid tissues. Quantitative RT-PCR assay was performed for determining the mRNA level of NOL4 while methylation-sensitive high resolution methylation was applied for assessing the methylation status with designing six pairs primers for six regions on gene promoter which were named from NOL4 (a) to NOL4 (f).

RESULTS

Methylation assessment of 81 CpG islands in the promoter region of NOL4 gene revealed that NOL4 (f), the nearest region to the start codon, was significantly hypermethylated in PTC cases compared to MNG cases. NOL4 level in PTC cases in comparison with MNG cases were downregulated. The methylation status and mRNA level of NOL4 (f) were associated with age of diagnosis (Age of the patient at the time of diagnosis), lymph node metastasis, and advanced stages of disease.

CONCLUSIONS

These data suggested an aberrant promoter hyper-methylation of NOL4 in PTC cases may be linked with its downregulation. Therefore, NOL4 gene can be proposed as a potential tumor suppressor gene in PTC tissues.

Association between TSHR gene methylation and papillary thyroid cancer: a meta-analysis

PURPOSE

To explore the association between the thyroid stimulating hormone receptor (TSHR) gene methylation and human papillary thyroid cancer (PTC), as well as PTC related clinicopathological indicators.

METHODS

We searched PubMed, Embase, Medline, and Web of Science databases through computer for articles published in English on association between methylation of TSHR gene and PTC. Articles published in Chinese were searched in China National Knowledge Infrastructure (CNKI), WanFang, China Biology Medicine (CBM) disc, and WeiPu databases. Database search took place in the 4th week of October.

RESULTS

Totally 914 samples from 14 case-control studies were included in our meta-analysis. The methylation rate of TSHR gene in PTC group was significantly greater than that in control group (OR = 6.45, 95% CI 3.03, 13.71, P < 0.001). The subgroup analysis results showed the incidence of TSHR gene methylation was higher in autologous controls (OR = 16.39, 95% CI 8.83, 30.42, P < 0.001), Asian races (OR = 8.26, 95% CI 3.54, 19.23, P < 0.001), and Chinese (OR = 11.40, 95% CI 5.56, 23.39, P < 0.001). Hierarchical analysis of PTC related clinicopathological indicators showed that TSHR gene methylation rate are higher in PTC patients over 45 years (OR = 1.65, 95% CI 1.07, 2.55, P < 0.05) and lymph node metastasis (OR = 5.36, 95% CI 1.54, 18.67, P < 0.01). In addition, the occurrence of TSHR gene methylation had also been shown to be related to the clinical stage (OR = 0.23, 95% CI 0.07, 0.70, P < 0.05) and size (OR = 0.19, 95% CI 0.11, 0.32, P < 0.01) of tumors. The result of sensitivity analysis showed the combined results of the studies included in the meta-analysis were fairly stable. Begg's and Egger's tests also suggested that there was no significance publication bias (P > 0.1).

CONCLUSIONS

The rate of TSHR gene methylation is higher in PTC and it may be associated with the pathogenesis of human PTC, suggesting that TSHR gene may be a candidate marker for PTC diagnosis. In addition, the occurrence of TSHR gene methylation in PTC patients is closely related to age, lymph node metastasis, clinical stage, and tumor size, suggesting that TSHR gene may be used as an index to judge the severity of PTC.

Diagnostic significance of DNA methylation of PTEN and DAPK in thyroid tumors

OBJECTIVE

DNA Methylation of the tumour suppressor gene leading to gene silencing plays an important role in thyroid tumour development. The purpose was to determine the DNA methylation status of phosphatase and tensin homolog (PTEN) and death-associated protein kinase (DAPK) in patients with thyroid nodules and to explore whether they can be used as molecular diagnostic tools to differentiate benign and malignant thyroid nodules.

DESIGN, PATIENTS AND MEASUREMENTS

Thyroid tissue and blood samples were obtained from normal healthy individuals (controls) and patients suffering from clinically diagnosed thyroid nodular disease [papillary thyroid carcinoma (PTC), adenoma and nodular goitre]. DNA methylation level, mRNA expression and protein expression of PTEN and DAPK in the thyroid tissues and peripheral blood were detected using methylation-specific PCR, semi-quantitative reverse transcription PCR and Western blot, respectively. Diagnostic sensitivity, specific and accuracy of detection were evaluated between blood and thyroid tissue.

RESULTS

There was a significant increase in the level of DNA methylation of PTEN and DAPK in PTC (P < .05) compared with controls and other types of thyroid nodules. Levels of the mRNA of both PTEN and DAPK were lower in PTC in both peripheral blood and tissue samples compared with controls, while there was concomitant decrease of both PTEN and DAPK protein expression in PTC tissues (P < .05). There was no significant difference in diagnostic specificity, sensitivity and accuracy between blood sample and thyroid tissues.

CONCLUSIONS

Hypermethylated status of both PTEN and DAPK in peripheral blood and tissue samples can be useful biomarkers for clinical diagnosis and, distinguishing of benign and malignant thyroid nodules.

Hypermethylated RASSF1 and SLC5A8 promoters alongside BRAFV600E mutation as biomarkers for papillary thyroid carcinoma

Circulating cell-free DNA (cfDNA) has been considered as a diagnostic source to track genetic and epigenetic alterations in cancer. We aimed to study mutation in addition to the methylation status in the promoter regions of RASSF1 and SLC5A8 genes in tissues and circulating free DNA samples of patients affected with papillary thyroid carcinoma (PTC) and thyroid nodules as controls. BRAF^V600E mutation was studied by ARMS-scorpion real-time polymerase chain reaction method in 57 PTC and 45 thyroid nodule cases. Methylation status of RASSF1 and SLC5A8 promoter regions was analyzed by methylation-specific high-resolution melting curve analysis. BRAF^V600E mutation was found in 39 (68.4%) out of 57 PTC tissue samples, while in 33 (49.1%) cases of cfDNA, this mutation was detected. The frequency of BRAF^V600E mutation in cfDNA was significantly different between metastatic and nonmetastatic PTC cases (22 of 33 PTC cases vs. 5 of 34 thyroid nodule samples). Methylation levels of three promoter regions of SLC5A8 and proximal promoter region of RASSF1 was significantly different between PTC and thyroid nodule cases in both cfDNA and tissue DNA. In addition, the methylation status of these two genes in tissue DNA was reflected in methylation status observed in cfDNA. This study confirmed that BRAF^V600E mutation is better for discrimination between papillary thyroid carcinoma and thyroid nodules. On the other hand, hypermethylation in the more proximal promoter regions to RASSF1 and SLC5A8 genes showed higher sensitivity and more acceptable specificity for this discrimination.

LDOC1 is differentially expressed in thyroid cancer and display tumor-suppressive function in papillary thyroid carcinoma

The leucine zipper downregulated in cancer 1 (LDOC1) has been proposed as a regulator of transcription and cell signaling. We have previously demonstrated that LDOC1 is differentially expressed in papillary thyroid carcinoma (PTC), this study was designed to characterize LDOC1 expression in thyroid follicle originated cancer tissues and to specifically evaluate its function in thyroid carcinogenesis. LDOC1 expression was performed in human normal thyroid and thyroid cancer. LDOC1 function was characterized, in two PTC cell lines (TPC1 and BCPAP), through the analysis of in vitro cell proliferation, apoptosis, migration, and invasion along with in vivo tumor xenograft growth. Transduced BCPAP cells were stimulated with tumor necrosis factor α, and the levels of nuclear P65, Bax, Bcl-2, c-Myc, and XIAP were assessed. A luciferase reporter assay was used to measure nuclear factor-κB (NF-κB) activity, and the functional connection between LDOC1 effect and NF-κB activity was determined using a specific NF-κB inhibitor. Our results revealed that LDOC1 was translocated from the nucleus to the cytoplasm in human thyroid cancer, and was significantly downregulated in PTC compared with normal thyroid. LDOC1 overexpression in TPC1 resulted in a significant suppression of the malignant phenotype, whereas LDOC1 ablation in BCPAP promoted this phenotype. Additional studies demonstrated that LDOC1 ablation facilitated nuclear P65 expression and NF-κB activity. NF-κB inhibition reversed the effects of LDOC1 ablation on proliferation, apoptosis, migration, and invasion. Our findings confirmed that LDOC1 is a novel therapeutic target in PTC and provides new insight into the role of LDOC1 in PTC progression, through NF-κΒ signaling suppression.

Promoter Methylation of Four Tumor Suppressor Genes in Human Papillary Thyroid Carcinoma

BACKGROUND & OBJECTIVE

Papillary thyroid cancer (PTC) is considered to be the most common type of thyroid malignancies. Epigenetic alteration, in which the chromatin conformation and gene expression change without changing the sequence of DNA, can occur in some tumor suppressor genes and oncogenes. Methylation is the most common type of epigenetic alterations that can be an excellent indicator of PTC invasive behavior.

METHODS

In this research, we determined the promoter methylation status of four tumor suppressor genes (SLC5A8, RASSF1, MGMT, and DNMT1) and compared the results of 55 PTC cases with 40 goiter patients. For methylation, we used the methylation-sensitive high resolution melting (MS-HRM) assay technique. The resulting graphs of each run were compared with those of 0%, 50%, and 100% methylated controls.

RESULTS

Our data showed that the promoter methylation of SLC5A8, Ras association domain family member 1(RASSF1), and MGMT were significantly different between PTC tissue and goiter with P-value less than 0.05. The most significant differences were observed in RASSF1; 77.2% of hyper-methylated PTC patients versus 15.6% hyper-methylated goiter samples (P<0.001).

CONCLUSION

RASSF1 promoter methylation can be a PTC genetic marker. RASSF1 promoter methylation is under the impact of the methyltransferase genes (DNMT1 and MGMT), protein expression, and promoter methylation.

Personalized treatment options for thyroid cancer: current perspectives

Thyroid cancer is one of the most common endocrine malignancies, with increasing incidence all over the world. In spite of good prognosis for differentiated thyroid carcinoma, for an unknown reason, about 5–10% of the patients, the cancer will show aggressive behavior, develop metastasis, and be refractory to treatment strategies like radioactive iodine. Regarding the genetic information, each thyroid cancer patient can be considered as an individual unique one, with unique genetic information. Contrary to standard chemotherapy drugs, target therapy components aim at one or more definite molecular pathway on cancer cells, so their selection is underlying patient’s genetic information. Nowadays, several mutations and rearrangements including BRAF, VEGF receptors, RET, and RET/PTC, KDR, KIT, PDGFRA, CD274, and JAK2 are taken into account for the therapeutic components like larotrectinib (TRK inhibitor), vemurafenib, sunitinib, sorafenib, selumetinib, and axitinib. With the new concept of personalized treatment of thyroid cancer diagnoses, planning treatment, finding out how well treatment will work, and estimating a prognosis has changed for the better over the last decade.

E-cadherin expression is associated with susceptibility and clinicopathological characteristics of thyroid cancer: A PRISMA-compliant meta-analysis

BACKGROUND

Recently, many studies have been carried out to investigate the clinicopathological significance of E-cadherin expression in thyroid cancer. However, the results remained inconsistent. In the present study, we performed a meta-analysis to evaluate the associations of E-cadherin expression with susceptibility and clinicopathological characteristics of thyroid cancer.

METHODS

Eligible studies were searched from Medicine, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), and Wanfang databases. The strength of associations between E-cadherin expression and susceptibility and clinicopathological features of thyroid cancer were assessed by pooled odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Forty-six studies with 1700 controls and 2298 thyroid cancer patients were included for this meta-analysis. Pooled results indicated that E-cadherin expression was significantly associated with susceptibility of papillary cancer and follicular cancer (papillary cancer, ORs = 14.31, 95% CIs = 3.42-59.90; follicular cancer, ORs = 10.14, 95% CI = 4.52-22.75). Significant association between E-cadherin expression and thyroid cancer risk was also observed in the subgroup analysis based on control group (normal thyroid tissue, ORs = 28.28, 95% CI = 8.36-95.63; adjacent thyroid tissue, ORs = 8.83, 95% CI = 3.27-23.85; benign thyroid tissue, ORs = 43.96, 95% CI = 9.91-194.95). In addition, E-cadherin expression was significantly correlated with lymph node metastasis, differentiation, and tumor-node-metastasis (TNM) stage of thyroid cancer (lymph node metastasis, ORs = 3.21, 95% CI = 1.98-5.20; differentiation, ORs = 0.25, 95% CI = 0.07-0.82; TNM stage, ORs = 4.85, 95% CI = 2.86-8.25).

CONCLUSIONS

The present study showed that E-cadherin expression was significantly associated with susceptibility and clinicopathological characteristics of thyroid cancer, which suggested that E-cadherin expression might be a potential predictive factor for clinical progression of thyroid cancer.

Liquid Biopsy as a Minimally Invasive Source of Thyroid Cancer Genetic and Epigenetic Alterations

In the blood of cancer patients, some nucleic acid fragments and tumor cells can be found that make it possible to trace tumor changes through a simple blood test called “liquid biopsy”. The main components of liquid biopsy are fragments of DNA and RNA shed by tumors into the bloodstream and circulate freely (ctDNAs and ctRNAs). Tumor cells which are shed into the blood (circulating tumor cells or CTCs), and exosomes that have been investigated for non-invasive detection and monitoring several tumors including thyroid cancer. Genetic and epigenetic alterations of a thyroid tumor can be a driver for tumor genesis or essential for tumor progression and invasion. Liquid biopsy can be real-time representative of such genetic and epigenetic alterations to trace tumors. In thyroid tumors, the circulating BRAF mutation is now taken into account for both thyroid cancer diagnosis and determination of the most effective treatment strategy. Several recent studies have indicated the ctDNA methylation pattern of some iodine transporters and DNA methyltransferase as a diagnostic and prognostic biomarker in thyroid cancer as well. There has been a big hope that the recent advances of genome sequencing together with liquid biopsy can be a game changer in oncology.

Circulating ctDNA methylation quantification of two DNA methyl transferases in papillary thyroid carcinoma

Papillary thyroid cancer (PTC) is the most common type of cancer among thyroid malignancies. Tumor-related methylation of circulating tumor DNA (ctDNA) in plasma could represent tumor specific alterations can be considered as good biomarkers in circulating tumor cells. In this study, we studied the methylation status of seven promoter regions of two DNA methyl Transferases (MGMT and DNMT1) genes as the methylated ctDNA in plasma and tissue samples of patients with PTC and goiter patients as noncancerous controls.

METHODS

Both ctDNA and tissue genomic DNA of 57 PTC and 45 Goiter samples were isolated. After bisulfite modification, the methylation status was studied by Methylation-Sensitive High Resolution Melting (MS-HRM) assay technique. Four promoter regions of O6-methylguanine-DNA methyltransferase (MGMT) and three promoter regions of DNA methyltransferase 1 (DNMT1) were assessed.

RESULTS

From seven candidate promoter regions of two methyltrasferase coding genes, the methylation status of ctDNA within MGMT (a), MGMT (c), MGMT (d), and DNMT1 (b) were meaningfully different between PTC cases and controls. However, the most significant differences were seen in circulating ctDNA MGMT (c) which was hypermethylated in 25 (43.9 %) of patients with PTC vs 2 (4. 4 %) of goiter samples. Between two selected DNA methyl transferase, the methylation of MGMT as the maintenance methyltransferase was significantly higher in PTC cases than goiter controls (P-value < .001). The resulting areas under the receiver operating characteristic (ROC) curve were 0.78 for MGMT (d) for PTC versus goiter samples that can represent the overall ability of MGMT (d) methylation status to discriminate between PTC and goiter patients.

CONCLUSION

Among seven candidate regions of ctDNA the MGMT (c) and MGMT (d) showed higher sensitivity and specificity for PTC as a suitable candidates as biomarkers of PTC.

Oncometabolites as biomarkers in thyroid cancer: a systematic review

INTRODUCTION

Thyroid cancer (TC) is an important common endocrine malignancy, and its incidence has increased in the past decades. The current TC diagnosis and classification tools are fine-needle aspiration (FNA) and histological examination following thyroidectomy. The metabolite profile alterations of thyroid cells (oncometabolites) can be considered for current TC diagnosis and management protocols.

METHODS

This systematic review focuses on metabolite alterations within the plasma, FNA specimens, and tissue of malignant TC contrary to benign, goiter, or healthy TC samples. A systematic search of MEDLINE (PubMed), Scopus, Embase, and Web of Science databases was conducted, and the final 31 studies investigating metabolite biomarkers of TC were included.

RESULTS

A total of 15 targeted studies and 16 untargeted studies revealed several potential metabolite signatures of TC such as glucose, fructose, galactose, mannose, 2-keto-d-gluconic acid and rhamnose, malonic acid and inosine, cholesterol and arachidonic acid, glycosylation (immunoglobulin G [IgG] Fc-glycosylation), outer mitochondrial membrane 20 (TOMM20), monocarboxylate transporter 4 (MCT4), choline, choline derivatives, myo-/scyllo-inositol, lactate, fatty acids, several amino acids, cell membrane phospholipids, estrogen metabolites such as 16 alpha-OH E1/2-OH E1 and catechol estrogens (2-OH E1), and purine and pyrimidine metabolites, which were suggested as the TC oncometabolite.

CONCLUSION

Citrate was suggested as the first most significant biomarker and lactate as the second one. Further research is needed to confirm these biomarkers as the TC diagnostic oncometabolite.

An integrated methylation and gene expression microarray analysis reveals significant prognostic biomarkers in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a life-threatening disease with a poor prognosis. Although previous studies have reported that the methylation of certain genes is associated with the pathogenesis of OSCC, the methylation of genes that have relevance to OSCC progression is not clearly documented. The present study aimed to gain insights into the mechanisms underlying DNA methylation regulation associated with OSCC progression and to identify potential prognostic markers for OSCC treatment. DNA methylation dataset GSE41114 and gene expression dataset GSE74530 were downloaded from the Gene Expression Omnibus database. The global methylation status of OSCC tumor samples and normal control samples was determined, and differentially methylated genes (DMGs) in OSCC samples compared with control samples were identified. The mRNA expression data were then integrated to identify differentially expressed genes (DEGs) in OSCC samples compared with control samples. Overlapping genes between DEGs and DMGs were identified, and functional enrichment analysis was performed. In addition, survival analysis of the overlapping genes was performed to screen genes with prognostic significance in OSCC. A total of 40,115 differential methylation CpG sites spanning 3,360 DMGs were identified; CpG sites in the promoter, gene body and intergenic regions were generally highly hypermethylated or hypomethylated. Additionally, 508 DEGs in OSCC samples were identified, including 332 upregulated and 176 downregulated genes. A total of 82 overlapping genes between DEGs and DMGs were found, which were mainly involved in protein metabolism, regulation of the metabolic process and the immune system. Additionally, differential methylation or expression of several genes, including fibroblast activation protein α (FAP), interferon α inducible protein 27 (IFI27), laminin subunit γ2 (LAMC2), matrix metallopeptidase 1 (MMP1), serine peptidase inhibitor Kazal-type 5 (SPINK5) and zinc finger protein 662 (ZNF662), was significantly associated with the survival of OSCC patients, and their differential expression in OSCC patients was further confirmed by reverse transcription-quantitative polymerase chain reaction in OSCC and normal oral cell lines. Overall, FAP, IFI27, LAMC2, MMP1, SPINK5 and ZNF662 genes caused by epigenetic changes via DNA methylation may be associated with the development and progression of OSCC, and should be valuable OSCC therapeutic biomarkers.

Multiple Endocrine Neoplasia Syndromes from Genetic and Epigenetic Perspectives

Multiple endocrine neoplasia (MEN) syndromes are infrequent inherited disorders in which more than one endocrine glands develop noncancerous (benign) or cancerous (malignant) tumors or grow excessively without forming tumors. There are 3 famous and well-known forms of MEN syndromes (MEN 1, MEN 2A, and MEN 2B) and a newly documented one (MEN4). These syndromes are infrequent and occurred in all ages and both men and women. Usually, germ line mutations that can be resulted in neoplastic transformation of anterior pituitary, parathyroid glands, and pancreatic islets in addition to gastrointestinal tract can be an indicator for MEN1. The medullary thyroid cancer (MTC) in association with pheochromocytoma and/or multiple lesions of parathyroid glands with hyperparathyroidism can be pointer of MEN2 which can be subgrouped into the MEN 2A, MEN 2B, and familial MTC syndromes. There are no distinct biochemical markers that allow identification of familial versus nonfamilial forms of the tumors, but familial MTC usually happens at a younger age than sporadic MTC. The MEN1 gene (menin protein) is in charge of MEN 1 disease, CDNK1B for MEN 4, and RET proto-oncogene for MEN 2. The focus over the molecular targets can bring some hope for both diagnosis and management of MEN syndromes. In the current review, we look at this disease and responsible genes and their cell signaling pathway involved.

Liquid Biopsy in Thyroid Cancer: New Insight

Thyroid cancer, one of the most widespread malignancies of the endocrine-related system that over the past three decades, has a vivid increasing rate. The diagnosis and management of it is dependent on the tumor type and stage. Thyroid cancer is divided into four main types, including PTC (papillary thyroid carcinoma), FTC (follicular thyroid carcinoma), MTC (medullarly thyroid carcinoma), and ATC (anaplastic thyroid carcinoma). The development of the noninvasive diagnostic tool for plasma genotyping, also known as "liquid biopsy", brings a new insight for cancer diagnosis and prognosis. It is mainly containing circulating tumor DNA (ctDNA), circulating tumor cell (CTC), exosomes and extrachromosomal circular DNA (ecDNA). Liquid biopsy as a new plasma genotyping source brings a new prospective of tumor monitoring and therapy. It beneficially reduces the need of tissue biopsy and made early recognition of relapse as well. This article summarizes its components characteristics and their benefit in diagnosis and treatment of thyroid cancer.

Circulating tumor DNA (ctDNA) in the era of personalized cancer therapy

The heterogeneity of tumor is considered as a major difficulty to victorious personalized cancer medicine. There is an extremeneed of consistent response evaluation for in vivo tumor heterogeneity anditscoupledconflict mechanisms. In this occasion researchers will be able to keep pace withpredictive, preventive, personalized, and Participatory (P4) medicine for cancer managements. In fact tumor heterogeneity is a central part of cancer evolution,soin order to progress in understanding of the dynamics within a tumor some diagnostic apparatus should be improved. Latest molecular techniques like Next generation Sequencing (NGS) and ultra-deep sequencing could disclose some clones within a liquid tumor biopsy which mainly responsible of treatment resistance. Circulating tumor DNA (ctDNA) as a main component of liquid biopsy is agifted biomarker for cancer mutation tracking as well as profiling. Personalized medicine facilitate learning regarding to genetic pools of tumor and their possible respond to treatment which could be much easier by using of ctDNA.With this information, cliniciansarelooking forward to find the best strategies for prevention, screening, and treatment in the way of precision medicine. Currently, numerous clinical efficacy of such informative improved treatment are in hand. Here we represent the review of plasma-derived ctDNA studies use in personalized cancer managements.

Preserved SCN4B expression is an independent indicator of favorable recurrence-free survival in classical papillary thyroid cancer

Voltage-gated sodium channel β subunits (encoded by SCN1B to SCN4B genes) have been demonstrated as important multifunctional signaling molecules modulating cellular processes such as cell adhesion and cell migration. In this study, we aimed to explore the expression profiles of SCN4B in papillary thyroid cancer (PTC) and its prognostic value in terms of recurrence-free survival (RFS) in classical PTC. In addition, we also examined the potential effect of DNA methylation on its expression. A retrospective study was performed by using data from available large databases, including the Gene Expression Omnibus (GEO) datasets and the Cancer Genome Atlas (TCGA)-Thyroid Cancer (THCA). Results showed that SCN4B is downregulated at both RNA and protein level in PTC compared with normal thyroid tissues. Preserved SCN4B expression was an independent indicator of favorable RFS in patients with classical PTC, no matter as categorical variables (HR: 0.243, 95%CI: 0.107–0.551, p = 0.001) or as a continuous variable (HR: 0.684, 95%CI: 0.520–0.899, p = 0.007). The methylation status of one CpG site (Chr11: 118,022,316–318) in SCN4B DNA had a moderately negative correlation with SCN4B expression in all PTC cases (Pearson’s r = -0.48) and in classical PTC cases (Pearson’s r = -0.41). In comparison, SCN4B DNA copy number alterations (CNAs) were not frequent and might not influence its mRNA expression. In addition, no somatic mutation was found in SCN4B DNA. Based on these findings, we infer that preserved SCN4B expression might independently predict favorable RFS in classical PTC. Its expression might be suppressed by DNA hypermethylation, but is less likely to be influenced by DNA CNAs/mutations.