Interaction of Age at Diagnosis with Transcriptional Profiling in Papillary Thyroid Cancer

Effect of Genetic Ancestry on Phenotypes and Genotypes in Papillary Thyroid Cancer

Thyroid cancer (THCA) is a prevalent health burden, and unpacking its biological and social determinants is a public health priority. Previous studies have reported inconsistent findings regarding the effects of race and ethnicity on the incidence and presentation of THCA. It remains unclear whether racial differences manifest at the molecular level. By harnessing the Cancer Genome Atlas papillary THCA dataset, this study derived genetic ancestry estimates from single nucleotide polymorphism array genotyping and exome sequencing data. Five ancestral groups (Europeans, East Asians, Africans, Native/Latin Americans, and South Asians) were included for analysis. We found a good agreement between genetic ancestry and reported race (Cramer's V = 0.730). Although differences in tumor size and patient age were observed, overall survival, progression-free interval, and disease-free interval were similar across the ancestral groups. Furthermore, the distribution of oncogenic drivers did not significantly differ among these groups. Weighted gene co-expression network analysis identified several ancestry-associated signatures. In conclusion, this study suggests that hereditary ancestral traits likely have little biological significance in papillary THCA. Instead, racial disparities in this type of cancer may be attributed to lifestyle factors, environmental exposures, and social and political power asymmetries in society and healthcare infrastructure.

Investigation of the mechanism of Prunella vulgaris in treatment of papillary thyroid carcinoma based on network pharmacology integrated molecular docking and experimental verification

To analyze the molecular mechanism of Prunella vulgaris L. (PV) in the treatment of papillary thyroid carcinoma (PTC) by using network pharmacology combined with molecular docking verification. Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform database was used to predict the main active components of PV, Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform, PubChem, and Swiss Target Prediction databases were used to obtain the corresponding targets of all active components. Targets collected for PTC treatment through Gene Cards, Digest and Online Mendelian Inheritance in Man databases respectively. The Search Tool for the Retrieval of Interaction Gene/Protein database was used to obtain the interaction information between proteins, and the topology analysis and visualization were carried out through Cytoscape 3.7.2 software (https://cytoscape.org/). The R package cluster profiler was used for gene ontology and Kyoto encyclopedia of genes and genomes analysis. The "active ingredient-target-disease" network was constructed by using Cyto scape 3.7.2, and topological analysis was carried out to obtain the core compound. The molecular docking was processed by using Discovery Studio 2019 software, and the core target and active ingredient were verified. The inhibition rate was detected by CCK8 method. Western blot was used to detect the expression levels of kaempferol anti-PTC related pathway proteins. A total of 11 components and 83 corresponding targets in the component target network of PV, of which 6 were the core targets of PV in the treatment of PTC. It was showed that quercetin, luteolin, beta (β)-sitosterol, kaempferol may be the core components of PV in the treatment of PTC. vascular endothelial growth factor A, tumor protein p53, transcription factor AP-1, prostaglandin endoperoxidase 2, interleukin 6, and IL-1B may be important targets for the treatment of PTC. The main biological processes mainly including response to nutrient levels, response to xenobiotic stimulus, response to extracellular stimulus, external side of plasma membrane, membrane raft, membrane microdomain, serine hydrolase activity, serine-type endopeptidase activity, antioxidant activity, etc IL-17 signaling pathway, and PI3K-Akt signaling pathway may affect the recurrence and metastasis of PTC. Kaempferol may significantly reduce the activity of Papillary cells of human thyroid carcinoma bcpap cell lines cells compared with quercetin, luteolin, β-sitosterol. Kaempferol may reduce the protein expression levels of interleukin 6, vascular endothelial growth factor A, transcription factor AP-1, tumor protein p53, 1L-1B and prostaglandin endoperoxidase 2, respectively. PV has the characteristics of multi-components, multi-targets and multi- pathways in the treatment of PTC, which network pharmacology help to provides a theoretical basis for the screening of effective components of PV and further research.

Reprogramming of Cellular Metabolism and Its Therapeutic Applications in Thyroid Cancer

Metabolism is a series of life-sustaining chemical reactions in organisms, providing energy required for cellular processes and building blocks for cellular constituents of proteins, lipids, carbohydrates and nucleic acids. Cancer cells frequently reprogram their metabolic behaviors to adapt their rapid proliferation and altered tumor microenvironments. Not only aerobic glycolysis (also termed the Warburg effect) but also altered mitochondrial metabolism, amino acid metabolism and lipid metabolism play important roles for cancer growth and aggressiveness. Thus, the mechanistic elucidation of these metabolic changes is invaluable for understanding the pathogenesis of cancers and developing novel metabolism-targeted therapies. In this review article, we first provide an overview of essential metabolic mechanisms, and then summarize the recent findings of metabolic reprogramming and the recent reports of metabolism-targeted therapies for thyroid cancer.

Transcriptomic Characteristics Associated With Aging in the Thyroid Gland

The aging thyroid is associated with a plethora of morphological and functional changes. Limited studies have addressed the gene expression signature in the aging thyroid, except for sporadic reports using data from postmortem samples in the Genotype-Tissue Expression (GTEx) project. In this investigation, we analyzed the RNA sequencing data of 58 samples of normal-appearing counterpart thyroid tissues from The Cancer Genome Atlas. Aging-correlated genes were identified by determining the Spearman rank-order correlation between patient age and gene expression level. Additionally, we performed gene set enrichment analysis and conducted a weighted correlation network analysis. The results were compared with those analyzed using the GTEx data. The over-represented protein class of aging-correlated genes is mainly metabolite interconversion enzymes. Our analyses identified alterations in immune and inflammatory responses, mitochondrial functions, cytoskeletal proteins, as well as amino acid and cytochrome P450 metabolism. There was no significant association between thyroid differentiation and age. Our findings may shed molecular light on thyroid disorders in the geriatric population.

Propensity Score-Matched Analysis to Identify Pathways Associated with Loss of Sodium Iodide Symporter in Papillary Thyroid Cancer

Sodium iodide symporter (NIS) expression in thyroid follicular cells plays an important role in normal physiology and radioactive iodine therapy for thyroid cancer. Loss of NIS expression is often seen in thyroid cancers and may lead to radioiodine refractoriness. To explore novel mechanisms of NIS repression beyond oncogenic drivers, clinical and RNA-seq data from the thyroid cancer dataset of The Cancer Genome Atlas were analyzed. Propensity score matching was used to control for various genetic background factors. We found that tumoral NIS expression was negatively correlated with tumor size. Additionally, low NIS expression was the only factor associated with recurrence-free survival in a Cox multivariate regression analysis. After matching for clinicopathologic profiles and driver mutations, the principal component analysis revealed distinct gene expressions between the high and low NIS groups. Gene set enrichment analysis suggested the downregulation of hedgehog signaling, immune networks, and cell adhesions. Positively enriched pathways included DNA replication, nucleotide excision repair, MYC, and Wnt/β-catenin pathways. In summary, we identified several potential targets which could be exploited to rescue the loss of NIS expression and develop redifferentiation strategies to facilitate radioactive iodine therapy for thyroid cancer.

Preoperative Factors Associated with Extrathyroidal Extension in Papillary Thyroid Cancer

OBJECTIVE

Extrathyroidal extension may not be accurately recognized during thyroidectomy and can increase the risk of positive margins and even recurrence. This study aimed to investigate the preoperative factors associated with extrathyroidal extension.

METHODS

We analyzed 887 patients with papillary thyroid cancer (PTC) who underwent surgery in the period of 2005-2017. Binary logistic regression analyses and generalized additive models were used to identify associations.

RESULTS

Minimal extrathyroidal extension was present in 233 (26%) patients and advanced extrathyroidal extension was found in 60 (7%) patients. Age, BMI, and tumor size were independent predictors of all or advanced extrathyroidal extension. Among the 493 patients whose BRAF mutation status was available, age (OR = 1.025), BMI (OR = 1.091), tumor size (OR = 1.544), and BRAF V600E mutation (OR = 2.311) were independently associated with extrathyroidal extension.

CONCLUSIONS

Older age, a greater BMI, a larger tumor size, and presence of the BRAF mutation were predictive of extrathyroidal extension. These factors should be taken into consideration in decision-making before surgery is performed.

Targeting the pentose phosphate pathway increases reactive oxygen species and induces apoptosis in thyroid cancer cells

The pentose phosphate pathway (PPP) plays an important role in the biosynthesis of ribonucleotide precursor and NADPH. Cancer cells frequently increase the flux of glucose into the PPP to support the anabolic demands and regulate oxidative stress. Consistently, metabolomic analyses indicate an upregulation of the PPP in thyroid cancer. In the present study, we found that the combination of glucose-6-phosphate dehydrogenase (G6PD) and transketolase inhibitors (6-aminonicotinamide and oxythiamine) exerted an additive or synergistic effect on cell growth inhibition in thyroid cancer cells. Targeting PPP significantly increased cellular reactive oxygen species (ROS) and induced endoplasmic reticulum (ER) stress and apoptosis. Suppressed cell viability could be partially rescued with treatment with the ROS scavenger or apoptosis inhibitor but not ER-stress inhibitor. Taken together, dual PPP blockade leads to pharmacologic additivity or synergism and causes ROS-mediated apoptosis in thyroid cancer cells.

Is papillary thyroid microcarcinoma a biologically different disease? A propensity score-matched analysis

BACKGROUND

Papillary thyroid microcarcinoma exhibits an indolent clinical course and could be a candidate for active surveillance in the appropriate setting. It remains unknown whether papillary microcarcinoma is biologically different from larger papillary carcinoma >1 cm.

METHODS

We analyzed clinicopathological information and transcriptome data of papillary thyroid cancer samples from The Cancer Genome Atlas. Propensity-score matching was used to construct a matched cohort consisting of 29 microcarcinomas and 58 carcinomas. Principal component analysis and unsupervised hierarchical cluster analysis were carried out to investigate the similarity of gene expression profiles.

RESULTS

After adjustment for differences in baseline clinicopathological and genetic factors, transcriptome could be grouped mainly on the basis of tumor class (BRAF-like vs RAS-like) and tumor size (microcarcinoma vs carcinoma). The gene set enrichment analysis showed that extracellular matrix-associated pathways were enriched in the MSigDB database.

CONCLUSION

Papillary thyroid microcarcinomas display a distinct gene expression pattern different from the corresponding carcinomas. We hypothesize that tumor microenvironment may play a role in the microcarcinoma/carcinoma phenotypic divergence.

PGC1α downregulation and glycolytic phenotype in thyroid cancer

Increased aerobic glycolysis portends an unfavorable prognosis in thyroid cancer. The metabolic reprogramming likely results from altered mitochondrial activity and may promote cancer progression. Peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α) plays a pivotal role in mitochondrial biogenesis and function. In the present study, we aimed to evaluate the clinicopathological significance of PGC1α expression and the potential effects of PGC1α modulation. Firstly, the expression of PGC1α in thyroid cancer samples was evaluated using western blot analysis and immunohistochemical staining. Compared with normal thyroid tissue, PGC1α expression was downregulated in thyroid cancer. PGC1α-negative papillary cancer was associated with BRAF V600E mutation, large tumor size, extrathyroidal or lymphovascular invasion, lymph node metastasis, and advanced stage. The results were consistent with the analysis of The Cancer Genome Atlas data. PGC1α expression correlated with oxygen consumption in thyroid cancer cells and was inversely related to AKT activity. The biologic relevance of PGC1α was further investigated by gain- and loss-of-function experimental studies. PGC1α overexpression led to augmented oxidative metabolism and accelerated tumor growth, whereas PGC1α knockdown induced a glycolytic phenotype but reduced tumor growth in vivo. In conclusion, PGC1α downregulation is associated with glycolytic metabolism and advanced disease in thyroid cancer. Nonetheless, manipulating PGC1α expression and metabolic phenotype does not necessarily translate into beneficial effects. It suggests that the metabolic phenotype is likely the consequence rather than the cause of disease progression in thyroid cancer.

Heme Oxygenase-1 Inhibitors Induce Cell Cycle Arrest and Suppress Tumor Growth in Thyroid Cancer Cells

Heme oxygenase-1 (HO-1) is induced by a variety of stimuli and plays a multifaceted role in cellular protection. We have shown that HO-1 is overexpressed in thyroid cancer and is associated with tumor aggressiveness. Therefore, we set out to assess the effects of HO-1 inhibitors on the biology of thyroid cancer cells. Two different classes of HO-1 inhibitors were used, including a metalloporphyrin, zinc protoporphyrin-IX (ZnPP), and an azole antifungal agent, ketoconazole. The viability and colony formation of thyroid cancer cells decreased in a concentration- and time-dependent fashion following treatment with HO-1 inhibitors. Cancer cells exhibited a higher sensitivity to HO-1 inhibitors than non-malignant cells. HO-1 inhibitors induced a G0/G1 arrest accompanied by decreased cyclin D1 and CDK4 expressions and an increase in levels of p21 and p27. HO-1 inhibitors significantly increased intracellular ROS levels and suppressed cell migration and invasion. Oxygen consumption rate and mitochondrial mass were increased with ZnPP treatment. Mice treated with ZnPP had a reduced xenograft growth and diminished cyclin D1 and Ki-67 staining in tumor sections. Taken together, HO-1 inhibitors might have therapeutic potential for inducing cell cycle arrest and promoting growth suppression of thyroid cancer cells in vitro and in vivo.

Transcriptome analysis of papillary thyroid cancer harboring telomerase reverse transcriptase promoter mutation

BACKGROUND

Telomerase reverse transcriptase (TERT) promoter mutations have recently been identified as an important prognostic factor in thyroid cancer. Studies suggest that TERT may have noncanonical functions beyond telomere maintenance.

METHODS

Clinicopathological information and transcriptome data for papillary thyroid carcinoma (PTC) samples were obtained from The Cancer Genome Atlas (TCGA). Propensity score matching was performed to adjust for potential confounding variables between the TERT promoter wild-type group and the mutant group. Gene expression data of 36 patients in the mutant group were systemically compared to those of 72 patients in the wild-type group.

RESULTS

Tumors with TERT promoter mutations had a higher TERT expression. Pathways central to DNA damage responses and cell cycle regulation were significantly enriched among 888 upregulated genes. Transporter and metabolic activities were overrepresented among 799 downregulated genes. There was no difference in the expression of most of the thyroid differentiation genes.

CONCLUSION

The TERT promoter mutations were associated with proliferative and metabolic alterations in PTC.

An Increased Neutrophil-to-Lymphocyte Ratio Predicts Incomplete Response to Therapy in Differentiated Thyroid Cancer

Background: Previously we have shown that an elevated baseline neutrophil-to-lymphocyte ratio (NLR) was associated with a high risk of recurrence in patients with differentiated thyroid cancer. The clinical significance of the longitudinal changes in NLR following treatment remained unestablished. Methods: Adults patients with differentiated thyroid cancer were included in the study if the follow-up NLR data at 6 to 18 months after initial treatment were available. The response to treatment was categorized as excellent, indeterminate, biochemical incomplete, and structural incomplete as per guidelines of the American Thyroid Association. Results: Among 151 patients with thyroid cancer, a significant decrease in NLR following treatment was observed in those with stage I disease, those with low risk of recurrence, and those with an excellent response to therapy. Patients with a structural incomplete response had a significant increase in NLR at follow-up (p = 0.012). On multivariate analysis, incomplete response to therapy was associated with male sex (odds ratio [OR] = 3.35), tumor size (OR = 1.63), lymph node metastasis (OR = 4.80), distant metastasis (OR = 12.95), and increased NLR (OR = 13.68). Conclusions: An increase in systemic inflammation following treatment as measured by NLR is independently associated with an incomplete response to therapy in differentiated thyroid cancer.

Overexpression of teneurin transmembrane protein 1 is a potential marker of disease progression in papillary thyroid carcinoma

Although papillary thyroid cancer is a relatively indolent malignancy, its progression may be associated with dedifferentiation and resistance to radioactive iodine treatment. In this study, patterns of differentially expressed genes in association with disease progression were systemically evaluated. We firstly performed transcriptome analyses for four matched cancerous and noncancerous tissue pairs of the classical subtype of papillary thyroid cancer. Among the upregulated and downregulated genes, the expression of 164 and 183 genes increased and decreased, respectively, from stage I to stage IV. Functional enrichment and pathway analysis showed that angiogenesis pathway was upregulated, whereas oxidation-reduction and metabolism of reactive oxygen species were downregulated. Teneurin transmembrane protein 1 (TENM1) expression was highly upregulated in cancerous tissues and negative in benign thyroid tissues. By immunohistochemistry, TENM1 expression in papillary thyroid cancer was associated with the classical subtype (p = 0.018), extrathyroidal invasion (p = 0.001), BRAF V600E mutation (p < 0.001), and an advanced stage (p = 0.019). Taken together, our results indicate that distinct pathways are involved in papillary thyroid cancer progression, and TENM1 is a potential marker of cancer progression.

Clinical predictors of lymph node metastasis and survival rate in papillary thyroid microcarcinoma: analysis of 3607 patients at a single institution

BACKGROUND

The treatment of papillary thyroid microcarcinoma (PTMC) patients is controversial, as PTMC is often found incidentally and its prognosis is quite good. Because lymph node metastasis (LNM) is one of the main predictors of recurrence and impacts the survival rate of PTMC patients, this study aims to retrospectively identify the clinical factors that increase the risk of LNM and/or recurrence and can then be used to separate clinically unfavorable PTMCs from the rest and to help guide their treatment accordingly.

METHODS

Clinical and pathologic data were collected from 3607 patients diagnosed with PTMC at Shanghai Renji Hospital between 2005 and 2015. Univariate and multivariate analyses were performed to identify the clinical predictors of LNM and survival rates were calculated by using the Kaplan-Meier method.

RESULTS

Our univariate and multivariate analyses show that age of <45 y (P < 0.01), gender of male (P < 0.01), tumor diameter >0.7 cm (P < 0.01), and multifocality (P < 0.01) significantly increase the risk of central LNM. However, clinical factors, such as LNM, age, gender, multifocality, and operation range, do not affect the 10-y disease-free survival rate (P > 0.05).

CONCLUSIONS

Clinical factors, such as gender of male, age of <45 y, multifocality, and tumor size >0.7 cm, suggest a higher risk of LNM; however, they do not affect PTMC patients' 10-y disease-free survival rate. We recommend ipsilateral lobectomy to PTMC patients. For PTMC patients with higher LNM risk, preoperative central and lateral cervical lymph node imaging examination should be emphasized, and lymph node dissection is recommended. The range of dissection should be determined based on the imaging results.

Dipeptidyl Peptidase IV as a Prognostic Marker and Therapeutic Target in Papillary Thyroid Carcinoma

CONTEXT

Dipeptidyl peptidase IV (DPP4) is overexpressed in thyroid cancer and certain malignancies. Furthermore, DPP4 has been identified as a discriminatory marker for thyroid cancer. However, it remains unclear whether DPP4 expression plays a prognostic role.

OBJECTIVE

The aim of this study was to investigate the expression and function of DPP4 in thyroid cancer and the mechanisms involved.

DESIGN

We determined the expression of DPP4 by immunohistochemistry in tissue microarrays of thyroid tumors. In vitro functional studies were performed after genetic and pharmacological inhibition of DPP4. Gene expression and pathway analyses were used to identify downstream targets. The therapeutic potential of DPP4 inhibition was evaluated in a mouse xenograft model.

RESULTS

High DPP4 expression was associated with extrathyroidal extension (P < 0.001), BRAF mutation (P < 0.001), and advanced tumor stage (P = 0.007) in papillary thyroid cancer. Patients in the high-DPP4 expression group were less likely to be classified as having no evidence of disease at final follow-up (P = 0.042). DPP4 silencing or treatment with DPP4 inhibitors significantly suppressed colony formation, cell migration, and invasion. Analysis of differentially expressed genes after DPP4 knockdown suggested that the transforming growth factor-β signaling pathway is involved. In vivo experiments revealed that sitagliptin treatment reduced tumor growth and xenograft transforming growth factor-β receptor I expression.

CONCLUSIONS

Increased DPP4 expression is associated with cellular invasion and more aggressive disease in papillary thyroid cancer. Targeting DPP4 may be a therapeutic strategy for DPP4-expressing thyroid cancer.

Nationwide cohort study on the epidemiology and survival outcomes of thyroid cancer

In the past three decades, the thyroid cancer incidence has surged globally. Herein, the Taiwan National Health Insurance database was used to identify thyroid cancer patients and to estimate the prevalence and incidence of thyroid cancer during 1997-2012. The Taiwan Cancer Registry and the National Death Registry databases were crosslinked to obtain information on the histological subtypes and survival rates. Joinpoint regression analysis was used for estimating the average annual percentage changes (APCs) in prevalence, incidence, and survival. The age-standardized incidence of thyroid cancer increased from 5.66 per 100,000 person-years in 1997 to 12.30 per 100,000 person-years in 2012, with an average APC of 5.1 (6.9 in males, 4.6 in females). Thyroid cancer was more prevalent in patients with high socioeconomic status and in urban areas. Papillary carcinoma was the most abundant subtype, with a 2.9-fold increase of incident cases noted during 1998-2012 (from 80.6% to 89.8% of all cases). Among the different treatments, partial thyroidectomy increased the most (average APC, 17.3). The overall survival rates by sex and subtype remained stable over time, with 5-year survival rates of 90.2% in 1997 and 92.4% in 2010. In conclusion, 2.2- and 4.2-fold increases in the incidence and prevalence of thyroid cancer, respectively, were observed during 1997-2012 in Taiwan. The surging incidence of thyroid cancer but stable survival rates, and mainly increased in the papillary subtype, altogether imply enhanced detection of subclinical lesions. A true increase due to environmental carcinogens might also be responsible, but warrant further investigations.

Recurrence-associated genes in papillary thyroid cancer: An analysis of data from The Cancer Genome Atlas

BACKGROUND

Recurrence of papillary thyroid cancer is not uncommon, but incorporating clinicopathologic parameters to predict recurrence is suboptimal. The aim of this study was to identify systemically recurrence-associated genes using The Cancer Genome Atlas RNA sequencing database.

METHODS

A total of 504 patients with transcriptome sequencing data of the primary neoplasm were included in this study. High and low levels of expression of each gene were defined by median splits. Differences in recurrence-free survival were compared using Kaplan-Meier curves and log-rank tests. Recurrence-associated genes were subjected to functional enrichment analyses with Kyoto Encyclopedia of Genes and Genomes annotation databases and Ingenuity Pathway Analysis.

RESULTS

We found that 1,807 genes were associated with recurrence-free survival. There were 676 genes of which high expression was associated with a greater risk of recurrence. These genes were enriched in pathways involved in cell cycle regulation and DNA repair. Among 1,131 genes of which low expression was associated with recurrence, Kyoto Encyclopedia of Genes and Genomes-annotated functions were metabolism, calcium signaling, glycan biosynthesis, and the Notch signaling pathway. Canonical pathways identified by Ingenuity Pathway Analysis included RXR function, nitric oxide signaling, interleukin-8 signaling, and nutrient sensing. In addition, low expression of the majority of thyroid differentiation genes was associated with a significantly less recurrence-free survival.

CONCLUSION

Upregulation of cell cycle-regulating and DNA repair genes appears to have a negative impact on recurrence-free survival in patients with papillary thyroid cancer. Furthermore, recurrence is associated with thyroid dedifferentiation.