Oncogenesis of Thyroid Cancer

Research progress and application of single-cell sequencing in head and neck malignant tumors

Single-cell sequencing (SCS) is a technology that separates thousands of cells from the organism and accurately analyzes the genetic material expressed in each cell using high-throughput sequencing technology. Unlike the traditional bulk sequencing approach, which can only provide the average value of a cell population and cannot obtain specific single-cell data, single-cell sequencing can identify the gene sequence and expression changes of a single cell, and reflects the differences between genetic material and protein between cells, and ultimately the role played by the tumor microenvironment. single-cell sequencing can further explore the pathogenesis of head and neck malignancies from the single-cell biological level and provides a theoretical basis for the clinical diagnosis and treatment of head and neck malignancies. This article will systematically introduce the latest progress and application of single-cell sequencing in malignant head and neck tumors.

The potential role of reprogrammed glucose metabolism: an emerging actionable codependent target in thyroid cancer

Although the incidence of thyroid cancer is increasing year by year, most patients, especially those with differentiated thyroid cancer, can usually be cured with surgery, radioactive iodine, and thyroid-stimulating hormone suppression. However, treatment options for patients with poorly differentiated thyroid cancers or radioiodine-refractory thyroid cancer have historically been limited. Altered energy metabolism is one of the hallmarks of cancer and a well-documented feature in thyroid cancer. In a hypoxic environment with extreme nutrient deficiencies resulting from uncontrolled growth, thyroid cancer cells utilize "metabolic reprogramming" to satisfy their energy demand and support malignant behaviors such as metastasis. This review summarizes past and recent advances in our understanding of the reprogramming of glucose metabolism in thyroid cancer cells, which we expect will yield new therapeutic approaches for patients with special pathological types of thyroid cancer by targeting reprogrammed glucose metabolism.

Molecular testing raises thyroid nodule fine needle aspiration diagnostic value

Thyroid fine needle aspiration biopsy (FNAB) remains indeterminate in 16%-24% of the cases. Molecular testing could improve the diagnostic accuracy of FNAB. This study examined the gene mutation profile of patients with thyroid nodules and analyzed the diagnostic ability of molecular testing for thyroid nodules using a self-developed 18-gene test. Between January 2019 and August 2021, 513 samples (414 FNABs and 99 formalin-fixed paraffin-embedded (FFPE) specimens) underwent molecular testing at Ruijin Hospital. Sensitivity (Sen), specificity (Spe), positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated. There were 457 mutations in 428 samples. The rates of BRAF, RAS, TERT promoter, RET/PTC, and NTRK3 fusion mutations were 73.3% (n=335), 9.6% (n=44), 2.8% (n=13), 4.8% (n=22), and 0.4% (n=2), respectively. The diagnostic ability of cytology and molecular testing were evaluated in Bethesda II and V-VI samples. For cytology alone, Sen, Spe, PPV, NPV, and accuracy were 100%, 25.0%, 97.4%, 100%, and 97.4%; these numbers were 87.5%, 50.0%, 98.0%, 12.5%, and 86.2% when considering positive mutation, and 87.5%, 75.0%, 99.0%, 17.6%, and 87.1% when considering positive cytology or and positive mutation. In Bethesda III-IV nodules, when relying solely on the presence of pathogenic mutations for diagnosis, Sen, Spe, PPV, NPV, and AC were 76.2%, 66.7%, 94.1%, 26.8%, and 75.0%, respectively. It might be necessary to analyze the molecular mechanisms of disease development at the genetic level to predict patients with malignant nodules more accurately in different risk strata and develop rational treatment strategies and definite management plans.

BRAF V600E and Novel Somatic Mutations in Thyroid Cancer of Libyan Patients

BACKGROUND

Thyroid cancer (TC) is a common endocrine malignancy that frequently harbours the oncogenic V600E BRAF mutation. This mutation has received considerable attention in recent years for its potential utility in the risk stratification and management of TC. This study aims to investigate BRAF mutational status in thyroid cancer of Libyan patients and their association with clinicopathological factors.

METHODS

44 thyroid tissue samples were analysed for mutations in exon 15 of the BRAF gene by performing polymerase chain reaction and Sanger sequencing. The results of BRAF mutation screening were correlated to clinical and pathological characteristics of the studied thyroid cancer patients. Statistical analyses were performed using SPSS.

RESULTS

The BRAF exon 15 mutations were detected in 19 (43.2%) of the thyroid cancer cases. The V600E was the most frequent one found in 15/44 (34.1%) cases. We also detected 6 other variants in 7 patients (15.9%), the S616F, the W619R and the T599S. Three mutations were associated with V600E, the L584I, the D587Y and the synonymous L597L. None of these mutations were reported previously in thyroid cancers. No statistical association was found between BRAF mutations and clinicopathological factors except with papillary thyroid cancer type (p= 0,032).

CONCLUSIONS

Novel BRAF mutations and V600E were frequently detected in thyroid cancer of Libyan patients; this suggests a potential role of these novel mutations in carcinogenesis and in anti-EGFR therapy resistance.

The Controversial Role of Vitamin D in Thyroid Cancer Prevention

Thyroid cancer is the most common endocrine malignancy and exhibits rising incidence. Annual incidence varies by sex, age, and geographical location. It has been reported that impairment of vitamin D signalling promotes thyroid cancer progression. Recent studies have shown that vitamin D, a fat-soluble vitamin that acts as both a nutrient and a hormone, may have utility in the prevention of autoimmune thyroid-related diseases. However, the precise role of vitamin D in the pathobiology of thyroid cancer is controversial. Previous studies have suggested that elevated serum vitamin D levels have a protective role in thyroid cancer. However, there is also evidence demonstrating no inverse relationship between vitamin D levels and the occurrence of thyroid cancer. Furthermore, recent data provide evidence that circulating vitamin D concentration is inversely correlated with disease aggressiveness and poor prognosis, while evidence of an association with tumour initiation remains weak. Nevertheless, a variety of data support an anti-tumorigenic role of vitamin D and its potential utility as a secondary chemopreventive agent. In this review, we highlighted recent findings regarding the association of vitamin D status with the risk of thyroid cancer, prognosis, potential mechanisms, and possible utility as a chemopreventive agent.

The Role of Altered Mitochondrial Metabolism in Thyroid Cancer Development and Mitochondria-Targeted Thyroid Cancer Treatment

Thyroid cancer (TC) is the most common type of endocrine malignancy. Tumour formation, progression, and metastasis greatly depend on the efficacy of mitochondria-primarily, the regulation of mitochondria-mediated apoptosis, Ca²⁺ homeostasis, dynamics, energy production, and associated reactive oxygen species generation. Recent studies have successfully confirmed the mitochondrial aetiology of thyroid carcinogenesis. In this review, we focus on the recent progress in understanding the molecular mechanisms of thyroid cancer relating to altered mitochondrial metabolism. We also discuss the repurposing of known drugs and the induction of mitochondria-mediated apoptosis as a new trend in the development of anti-TC therapy.

PRKAR1A and Thyroid Tumors

Simple Summary

In 2021 it is estimated that there will be 44,280 new cases of thyroid cancer in the United States and the incidence rate is higher in women than in men by almost 3 times. Well-differentiated thyroid cancer is the most common subtype of thyroid cancer and includes follicular (FTC) and papillary (PTC) carcinomas. Over the last decade, researchers have been able to better understand the molecular mechanisms involved in thyroid carcinogenesis, identifying genes including but not limited to RAS, BRAF, PAX8/PPARγ chromosomal rearrangements and others, as well as several tumor genes involved in major signaling pathways regulating cell cycle, differentiation, growth, or proliferation. Patients with Carney complex (CNC) have increased incidence of thyroid tumors, including cancer, yet little is known about this association. CNC is a familial multiple neoplasia and lentiginosis syndrome cause by inactivating mutations in the PRKAR1A gene which encodes the regulatory subunit type 1α of protein kinase A. This work summarizes what we know today about PRKAR1A defects in humans and mice and their role in thyroid tumor development, as the first such review on this issue.

Abstract

Thyroid cancer is the most common type of endocrine malignancy and the incidence is rapidly increasing. Follicular (FTC) and papillary thyroid (PTC) carcinomas comprise the well-differentiated subtype and they are the two most common thyroid carcinomas. Multiple molecular genetic and epigenetic alterations have been identified in various types of thyroid tumors over the years. Point mutations in BRAF, RAS as well as RET/PTC and PAX8/PPARγ chromosomal rearrangements are common. Thyroid cancer, including both FTC and PTC, has been observed in patients with Carney Complex (CNC), a syndrome that is inherited in an autosomal dominant manner and predisposes to various tumors. CNC is caused by inactivating mutations in the tumor-suppressor gene encoding the cyclic AMP (cAMP)-dependent protein kinase A (PKA) type 1α regulatory subunit (PRKAR1A) mapped in chromosome 17 (17q22–24). Growth of the thyroid is driven by the TSH/cAMP/PKA signaling pathway and it has been shown in mouse models that PKA activation through genetic ablation of the regulatory subunit Prkar1a can cause FTC. In this review, we provide an overview of the molecular mechanisms contributing to thyroid tumorigenesis associated with inactivation of the RRKAR1A gene.

Analytic validation and clinical utilization of the comprehensive genomic profiling test, GEM ExTra®

We developed and analytically validated a comprehensive genomic profiling (CGP) assay, GEM ExTra, for patients with advanced solid tumors that uses Next Generation Sequencing (NGS) to characterize whole exomes employing a paired tumor-normal subtraction methodology. The assay detects single nucleotide variants (SNV), indels, focal copy number alterations (CNA), TERT promoter region, as well as tumor mutation burden (TMB) and microsatellite instability (MSI) status. Additionally, the assay incorporates whole transcriptome sequencing of the tumor sample that allows for the detection of gene fusions and select special transcripts, including AR-V7, EGFR vIII, EGFRvIV, and MET exon 14 skipping events. The assay has a mean target coverage of 180X for the normal (germline) and 400X for tumor DNA including enhanced probe design to facilitate the sequencing of difficult regions. Proprietary bioinformatics, paired with comprehensive clinical curation results in reporting that defines clinically actionable, FDA-approved, and clinical trial drug options for the management of the patient's cancer. GEM ExTra demonstrated analytic specificity (PPV) of > 99.9% and analytic sensitivity of 98.8%. Application of GEM ExTra to 1,435 patient samples revealed clinically actionable alterations in 83.9% of reports, including 31 (2.5%) where therapeutic recommendations were based on RNA fusion findings only.

DNA repair pathway activation features in follicular and papillary thyroid tumors, interrogated using 95 experimental RNA sequencing profiles

DNA repair can prevent mutations and cancer development, but it can also restore damaged tumor cells after chemo and radiation therapy. We performed RNA sequencing on 95 human pathological thyroid biosamples including 17 follicular adenomas, 23 follicular cancers, 3 medullar cancers, 51 papillary cancers and 1 poorly differentiated cancer. The gene expression profiles are annotated here with the clinical and histological diagnoses and, for papillary cancers, with BRAF gene V600E mutation status. DNA repair molecular pathway analysis showed strongly upregulated pathway activation levels for most of the differential pathways in the papillary cancer and moderately upregulated pattern in the follicular cancer, when compared to the follicular adenomas. This was observed for the BRCA1, ATM, p53, excision repair, and mismatch repair pathways. This finding was validated using independent thyroid tumor expression dataset PRJEB11591. We also analyzed gene expression patterns linked with the radioiodine resistant thyroid tumors (n = 13) and identified 871 differential genes that according to Gene Ontology analysis formed two functional groups: (i) response to topologically incorrect protein and (ii) aldo-keto reductase (NADP) activity. We also found RNA sequencing reads for two hybrid transcripts: one in-frame fusion for well-known NCOA4-RET translocation, and another frameshift fusion of ALK oncogene with a new partner ARHGAP12. The latter could probably support increased expression of truncated ALK downstream from 4th exon out of 28. Both fusions were found in papillary thyroid cancers of follicular histologic subtype with node metastases, one of them (NCOA4-RET) for the radioactive iodine resistant tumor. The differences in DNA repair activation patterns may help to improve therapy of different thyroid cancer types under investigation and the data communicated may serve for finding additional markers of radioiodine resistance.

Canadian Consensus for Biomarker Testing and Treatment of TRK Fusion Cancer in Adults

The tyrosine receptor kinase (TRK) inhibitors larotrectinib and entrectinib were recently approved in Canada for the treatment of solid tumours harbouring neurotrophic tyrosine receptor kinase (NTRK) gene fusions. These NTRK gene fusions are oncogenic drivers found in most tumour types at a low frequency (<5%), and at a higher frequency (>80%) in a small number of rare tumours (e.g., secretory carcinoma of the salivary gland and of the breast). They are generally mutually exclusive of other common oncogenic drivers. Larotrectinib and entrectinib have demonstrated impressive overall response rates and tolerability in Phase I/II trials in patients with TRK fusion cancer with no other effective treatment options. Given the low frequency of TRK fusion cancer and the heterogeneous molecular testing landscape in Canada, identifying and optimally managing such patients represents a new challenge. We provide a Canadian consensus on when and how to test for NTRK gene fusions and when to consider treatment with a TRK inhibitor. We focus on five tumour types: thyroid carcinoma, colorectal carcinoma, non-small cell lung carcinoma, soft tissue sarcoma, and salivary gland carcinoma. Based on the probability of the tumour harbouring an NTRK gene fusion, we also suggest a tumour-agnostic consensus for NTRK gene fusion testing and treatment. We recommend considering a TRK inhibitor in all patients with TRK fusion cancer with no other effective treatment options.

Is there adenoma-carcinoma sequence between benign adenoma and papillary cancer of thyroid: A genomic linkage study

BACKGROUND

The adenoma-carcinoma sequence in thyroid nodules is an enigmatic phenomenon. Genomics is the only definitive modality to resolve this hypothesis. Adenomas and papillary carcinomas tend to have mutations in RAS and highly specific BRAF gene respectively. In this context, we set out study the prevalence and clinical significance of these somatic mutations in surgical tissue samples.

MATERIAL AND METHODS

This retrospective study was conducted on surgically managed thyroid nodule patients. Institutional ethical committee approval was obtained. Diagnosis was based on biochemical confirmation, imaging, fine needle aspiration cytology and later confirmed by histopathology. We selected 100 benign thyroid adenomas (BTA) and 100 papillary thyroid carcinoma (PTC) cases. Archived tumour tissue samples of selected cases were retrieved. After appropriate processing of samples, DNA extraction, cDNA preparation, PCR amplification, application of 4 sets of Primers were performed as part of mutational analysis of RAS (H-,K-,N-) and BRAF genes.

RESULTS

Homozygous mutations in N-RAS were found in 36/100 (36%) of BTA and 7/100 (7%) of PTC cases. No H-RAS or K-RAS mutations were found in both groups. Homozygous mutations were found in BRAF gene in 4/100 (4%) of BTA cases and 52/100 (52%) of PTC cases. The differences were statistically significant.

CONCLUSIONS

Similar N-RAS and BRAF mutations were prevalent in both benign and malignant thyroid nodules giving some evidence for linkage between them. Though not robust, we opine that there is possibility of adenoma-carcinoma sequence in thyroid nodules.

[The role of molecular testing in thyroid tumors]

&sup1;I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia; &sup2;Endocrinology Research Centre, Moscow, Russia Thyroid cancer is the most common endocrine gland cancer. In the last few decades, the molecular diagnostics for thyroid tumors have been widely researched. It is one of the few cancers whose incidence has increased in recent years from microcarcinomas to common, large forms, in all age groups, from children to the elder people. Most researches focus on the genetic basis, since our current knowledge of the genetic background of various forms of thyroid cancer is far from being complete. Molecular and genetic research has several main directions: firstly, differential diagnosis of thyroid tumors, secondly, the prognostic value of detected mutations in thyroid cancer, and thirdly, targeted therapy for aggressive or radioactive iodine-resistant forms of thyroid cancer. In this review, we wanted to update our understanding and describe the prevailing advances in molecular genetics of thyroid cancer, focusing on the main genes associated with the pathology and their potential application in clinical practice.

Diagnostic Accuracy of Preoperative Neutrophil-to-Lymphocyte and Platelet-to-Lymphocyte Ratios in Detecting Occult Papillary Thyroid Microcarcinomas in Benign Multinodular Goitres

Objective

To investigate the diagnostic accuracy of neutrophil-to-lymphocyte (NLR) and platelet-to-lymphocyte (PLR) ratios in detecting occult papillary thyroid microcarcinomas in benign, multinodular goitres.

Methods

397 total thyroidectomy patients were identified from the institutional thyroid surgery database between 2007 and 2016 (94 males, 303 females, mean age 53 ± 14.5 years). NLR and PLR were calculated as the absolute neutrophil and absolute platelet counts divided by the absolute lymphocyte count, respectively, based on the preoperative complete blood cell count.

Results

NLR was significantly higher in carcinomas and microcarcinomas compared to benign pathology (p = 0.026), whereas a direct association could not be established for PLR. Both NLR and PLR scored low in all parameters of diagnostic accuracy, with overall accuracy ranging between 45 and 50%.

Conclusions

As surrogate indices of the systemic inflammatory response, NLR and PLR are inexpensive and universally available from routine blood tests. Although we found higher NLR values in cases of malignancy, NLR and PLR cannot effectively predict the presence of occult papillary microcarcinomas in otherwise benign, multinodular goitres.

Reverting iodine avidity of radioactive-iodine refractory thyroid cancer with a new tyrosine kinase inhibitor (K905-0266) excavated by high-throughput NIS (sodium iodide symporter) enhancer screening platform using dual reporter gene system

Radioactive-iodine (RAI) therapy is typically unprevailing as anaplastic thyroid cancer (ATC) management, owing to the decrease in the endogenous sodium iodide symporter (NIS) expression. Therefore, new strategies for NIS re-induction are required to improve the efficacy of RAI therapy in ATC. In this study, we developed a novel high-throughput NIS enhancer screening platform using a dual reporter gene system to identify a potent tyrosine kinase inhibitor (TKI) and selected a new hit compound, K905-0266 TKI. The effects of K905-0266 TKI treatment was validated as RAI accumulation, changes in signalling pathway related to thyroid pathogenesis, and cytotoxicity of RAI depending on re-induction of endogenous NIS expression in ATC. Furthermore, we evaluated enhancement of NIS promoter and therapeutic efficacy of RAI in ATC tumour xenograft mice. After K905-0266 TKI treatment, the expression of endogenous NIS was significantly increased, while phosphorylated-ERK was decreased. In addition, the thyroid-metabolising protein expressions were upregulated and increased of RAI accumulation and its therapeutic effects in ATC. Moreover, K905-0266 TKI increased therapeutic efficacy of RAI in ATC tumour in vivo. In conclusion, we successfully established a novel high-throughput NIS enhancer screening platform to excavate a NIS enhancer and identified K905-0266 TKI among TKI candidates and it's proven to increase the endogenous NIS expression and therapeutic efficacy of RAI in ATC. These findings suggest that a novel high-throughput NIS enhancer screening platform is useful for selecting of NIS promoter enhancers. In addition, K905-0266 TKI can be used to re-induce endogenous NIS expression and recover RAI therapy in ATC.