The Role of Lipid Metabolism Disorders in the Development of Thyroid Cancer

Thyroid cancer (TC) is a neoplasm with an increasing incidence worldwide. Its etiology is complex and based on a multi-layered interplay of factors. Among these, disorders of lipid metabolism have emerged as an important area of investigation. Cancer cells are metabolically reprogrammed to promote their rapid growth, proliferation, and survival. This reprogramming is associated with significant changes at the level of lipids, mainly fatty acids (FA), as they play a critical role in maintaining cell structure, facilitating signaling pathways, and providing energy. These lipid-related changes help cancer cells meet the increased demands of continued growth and division while adapting to the tumor microenvironment. In this review, we examine lipid metabolism at different stages, including synthesis, transport, and oxidation, in the context of TC and the effects of obesity and hormones on TC development. Recent scientific efforts have revealed disturbances in lipid homeostasis that are specific to thyroid cancer, opening up potential avenues for early detection and targeted therapeutic interventions. Understanding the intricate metabolic pathways involved in FA metabolism may provide insights into potential interventions to prevent cancer progression and mitigate its effects on surrounding tissues.

Could Oxidative Stress Play a Role in the Development and Clinical Management of Differentiated Thyroid Cancer?

Increased oxidative stress (OS) has been implicated as a relevant risk factor for cancer progression. Furthermore, patients diagnosed with differentiated thyroid cancer (DTC) have been characterized by an increased OS status. Therefore, assessing OS status could potentially be considered a useful tool in DTC clinical management. This measurement could be particularly valuable in personalizing treatment protocols and determining new potential medical targets to improve commonly used therapies. A literature review was conducted to gather new information on DTC clinical management, with a particular focus on evaluating the clinical utility of OS. These meta-analyses concentrate on novel approaches that employ the measurement of oxidative-antioxidant status, which could represent the most promising area for implementing clinical management.

Biomarkers of oxidative stress and reproductive complications

Oxidative stress is the result of an imbalance between the formation of reactive oxygen species (ROS) and the levels of enzymatic and non-enzymatic antioxidants. The assessment of biological redox status is performed by the use of oxidative stress biomarkers. An oxidative stress biomarker is defined as any physical structure or process or chemical compound that can be assessed in a living being (in vivo) or in solid or fluid parts thereof (in vitro), the determination of which is a reproducible and reliable indicator of oxidative stress. The use of oxidative stress biomarkers allows early identification of the risk of developing diseases associated with this process and also opens up possibilities for new treatments. At the end of the last century, interest in oxidative stress biomarkers began to grow, due to evidence of the association between the generation of free radicals and various pathologies. Up to now, a significant number of studies have been carried out to identify and apply different oxidative stress biomarkers in clinical practice. Among the most important oxidative stress biomarkers, it can be mentioned the products of oxidative modifications of lipids, proteins, nucleic acids, and uric acid as well as the measurement of the total antioxidant capacity of fluids in the human body. In this review, we aim to present recent advances and current knowledge on the main biomarkers of oxidative stress, including the discovery of new biomarkers, with emphasis on the various reproductive complications associated with variations in oxidative stress levels.

Synthesis and Antiproliferative Effect of Halogenated Coumarin Derivatives

A series of 6- and 6,8-halocoumarin derivatives have been investigated as potential antiproliferative compounds against a panel of tumor and normal cell lines. Cytotoxic effects were determined by the MTT method. To investigate the potential molecular mechanism involved in the cytotoxic effect, apoptosis assay, cell cycle analysis, reactive oxygen species (ROS), and reduced glutathione analysis were performed. Among the screened compounds, coumarins 6,8-dibromo-2-oxo-2H-chromene-3-carbonitrile 2h and 6,8-diiodo-2-oxo-2H-chromene-3-carbonitrile 2k exhibited the most antiproliferative effect in thyroid cancer-derived cells TPC-1. The apoptosis assay showed that both 2h and 2k induced apoptosis in TPC-1 thyroid cancer cells. According to these experiments, both coumarins induced a slight increase in TPC-1 cells in the G2/M phase and a decrease in the S phase. A significant increase in ROS levels was observed in TPC-1 treated with diiodocoumarin 2k, while the dibromocoumarin 2h induced a decrease in ROS in a dose and time-dependent manner.

Oxidative Stress Correlates with More Aggressive Features in Thyroid Cancer

Oxidative stress (OS) can have an impact in the pathogenesis and in the progression of thyroid cancer. We investigated the levels of reactive oxygen species (ROS) in 50 malignant and benign thyroid lesions and 41 normal tissues, and correlated them with the thyroid differentiation score-TDS and the clinico-pathologic features. NOX4 expression, GPx activity and the genetic pattern of tumors were evaluated. In malignant and benign lesions, ROS generation and NOX4 protein expression were higher than in normal tissues. Follicular (FTCs) and anaplastic/poorly differentiated cancers had increased OS relative to papillary tumors (PTCs). Moreover, OS in FTCs was higher than in follicular adenomas. Mutated PTCs showed increased OS compared with non-mutated PTCs. In malignant tumors, OS was inversely correlated with TDS, and directly correlated with tumor stage and ATA risk. GPx activity was increased in tumors compared with normal tissues, and inversely correlated to OS. In conclusion, our data indicate that thyroid tumors are exposed to higher OS compared with normal tissues, while showing a compensative increased GPx activity. OS correlates with tumor aggressiveness and mutations in the MEK-ERK pathway in PTC. The inverse correlation between OS and TDS suggests that ROS may repress genes involved in thyroid differentiation.

Role of papillary thyroid carcinoma patients with Hashimoto thyroiditis: evaluation of oxidative stress and inflammatory markers

PURPOSE

Papillary thyroid carcinoma (PTC) is the most frequent subtype of thyroid cancer; Hashimoto's thyroiditis (HT), autoimmune disease, commonly affects the thyroid gland; there is possibly a correlation between both, but the exact mechanisms that involve this relationship are still under debate. Since oxidative stress (OS) and the inflammatory environment participate in the development of several types of cancer, the objective of the present study was to establish the microenvironment and systemic participation of OS and inflammatory markers in patients with PTC and HT.

METHODS

Blood and tissue samples were collected from 115 patients: BENIGN (n = 63); PTC (n = 27); HT (n = 15) and PTC + HT (n = 10), and sixty-three were samples from healthy individuals (control group).

RESULTS

Superoxide dismutase, Catalase, reduced Glutathione, markers of lipid peroxidation and inflammation were evaluated in blood. Immunohistochemistry was performed on 3-nitrotyrosine, 4-hydroxynonenal, Ki-67 and VEGF. The results indicate that antioxidant enzymes were more active in groups with thyroid disorders compared to control, while the concentration of Reduced glutathione was reduced in BENIGN and PTC groups. When PTC and PTC + HT groups were analyzed, no significant differences were found in relation to the antioxidant defense and inflammatory markers. The ability to contain the induced lipid peroxidation was lower and a high level of malondialdehyde was observed in the PTC group. All immunohistochemical markers had higher scores in the PTC group compared to PTC + HT.

CONCLUSION

There was a more pronounced presence of OS and a greater activity of cell proliferation and angiogenesis markers in PTC than in PTC + HT group.

Metabolomics of Esophageal Squamous Cell Carcinoma Tissues: Potential Biomarkers for Diagnosis and Promising Targets for Therapy

Background

The incidence of esophageal squamous cell carcinoma in China ranks first in the world. The early diagnosis technology is underdeveloped, and the prognosis is poor, which seriously threatens the quality of life of the Chinese people. Epidemiological findings are related to factors such as diet, living habits, and age. The specific mechanism is not clear yet. Metabolomics is a kind of omics that simultaneously and quantitatively analyzes the comprehensive profile of metabolites in living systems. It has unique advantages in the study of the diagnosis and pathogenesis of tumor-related diseases, especially in the search for biomarkers. Therefore, it is desirable to perform metabolic profiling analysis of cancer tissues through metabolomics to find potential biomarkers for the diagnosis and treatment of esophageal squamous cell carcinoma.

Methods

HPLC-TOF-MS/MS technology and Illumina Hiseq Xten Sequencing was used for the analysis of 210 pairs of matched esophageal squamous cell carcinoma tissues and normal tissues in Zhenjiang City, Jiangsu Province, a high-incidence area of esophageal cancer in China. Bioinformatics analysis was also performed.

Results

Through metabolomic and transcriptomic analysis, this study found that a total of 269 differential metabolites were obtained in esophageal squamous cell carcinoma and normal tissues, and 48 differential metabolic pathways were obtained through KEGG enrichment analysis. After further screening and identification, 12 metabolites with potential biomarkers to differentiate esophageal squamous cell carcinoma from normal tissues were obtained.

Conclusions

From the metabolomic data, 4 unknown compounds were found to be abnormally expressed in esophageal squamous cell carcinoma for the first time, such as 9,10-epoxy-12,15-octadecadienoate; 3 metabolites were found in multiple abnormal expression in another tumor, but upregulation or downregulation was found for the first time in esophageal cancer, such as oleoyl glycine; at the same time, it was further confirmed that five metabolites were abnormally expressed in esophageal squamous cell carcinoma, which was similar to the results of other studies, such as PE.

Redox Homeostasis in Thyroid Cancer: Implications in Na+/I- Symporter (NIS) Regulation

Radioiodine therapy (RAI) is a standard and effective therapeutic approach for differentiated thyroid cancers (DTCs) based on the unique capacity for iodide uptake and accumulation of the thyroid gland through the Na⁺/I⁻ symporter (NIS). However, around 5–15% of DTC patients may become refractory to radioiodine, which is associated with a worse prognosis. The loss of RAI avidity due to thyroid cancers is attributed to cell dedifferentiation, resulting in NIS repression by transcriptional and post-transcriptional mechanisms. Targeting the signaling pathways potentially involved in this process to induce de novo iodide uptake in refractory tumors is the rationale of “redifferentiation strategies”. Oxidative stress (OS) results from the imbalance between ROS production and depuration that favors a pro-oxidative environment, resulting from increased ROS production, decreased antioxidant defenses, or both. NIS expression and function are regulated by the cellular redox state in cancer and non-cancer contexts. In addition, OS has been implicated in thyroid tumorigenesis and thyroid cancer cell dedifferentiation. Here, we review the main aspects of redox homeostasis in thyrocytes and discuss potential ROS-dependent mechanisms involved in NIS repression in thyroid cancer.

Comparing Oxidative Stress Status Among Iranian Males and Females with Malignant and Non-malignant Thyroid Nodules

BACKGROUND

Oxidative stress is commonly accrued in thyroid tissue during hormone synthesis.

OBJECTIVES

We aimed to examine oxidative stress in patients with thyroid cancer, benign thyroid nodules, and healthy individuals.

METHODS

In this study, 138 individuals were involved. Among the selected participants, 108 had thyroid nodules, including 30 papillary thyroid cancer (PTC), 30 follicular thyroid cancer (FTC), six anaplastic thyroid cancer (ATC), 12 medullary thyroid cancer (MTC), and 30 benign nodules. In addition, 30 individuals were selected as a healthy control group. The levels of total antioxidant capacity (TAC) and total oxidant status (TOS) of thyroid tissue were measured using the ELISA method, and the oxidative stress index (OSI) was calculated.

RESULTS

The TAC level was significantly lower in MTC and FTC subtypes than in controls. The TOS level was considerably higher in the MTC group than in the control and benign nodule groups. The TOS level was not changed in other groups. The OSI was considerably higher in MTC and FTC subtypes. The TAC and OSI in benign nodules were significantly lower and higher than those of controls, respectively. The OSI was higher in female patients than in males.

CONCLUSIONS

The OSI can not be considered a diagnostic biomarker for benign nodules and MTC. The diverse oxidative stress status between genders may be related to the elevated cancer incidence in females.

hMTH1 and GPX1 expression in human thyroid tissue is interrelated to prevent oxidative DNA damage

Oxidative stress (OS) is recognized as disturbance of cellular equilibrium between reactive oxygen species (ROS) formation and their elimination by antioxidant defense systems. One example of ROS-mediated damage is generation of potentially mutagenic DNA precursor, 8-oxodGTP. In human cells genomic 8-oxodGTP incorporation is prevented by the MutT homologue 1 (MTH1 or hMTH1 for human MTH1) protein. It is well established that malignant cells, including thyroid cancer cells, require hMTH1 for maintaining proliferation and cancerous transformation phenotype. Above observations led to the development of hMTH1 inhibitors as novel anticancer therapeutics. In the current study we present extensive analysis of oxidative stress responses determining sensitivity to hMTH1 deficiency in cultured thyroid cells. We observe here that hMTH1 depletion results in downregulation of several glutathione-dependent OS defense system factors, including GPX1 and GCLM, making some of the tested thyroid cell lines highly dependent on glutathione levels. This is evidenced by the increased ROS burden and enhanced proliferation defect after combination of hMTH1 siRNA and glutathione synthesis inhibition. Moreover, due to the lack of data on hMTH1 expression in human thyroid tumor specimens we decided to perform detailed analysis of hMTH1 expression in thyroid tumor and peri-tumoral tissues from human patients. Our results allow us to propose here that anticancer activity of hMTH1 suppression may be boosted by combination with agents modulating glutathione pool, but further studies are necessary to precisely identify backgrounds susceptible to such combination treatment.

Oxidative stress values of tumor core, edge, and healthy thyroid tissue in thyroid masses

PURPOSE

Reactive oxygen radicals play an important role in tumor formation, progression, and invasion. In this study, the aim was to investigate the relationship between the oxidative stress values of tumor core, edge, and healthy thyroid tissue in thyroid tumors.

METHODS

A total of 51 patients with thyroid tumor, 24-malignant, and 27-benign, were included in this study. Samples, measuring 5 × 5 × 5 mm, were taken from the tumor core, edge, and healthy thyroid tissue of the participants. Total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) values were examined. The oxidative stress values of core, edge, and healthy thyroid tissue of all tumors (n = 51) were compared according to the localization. The participants were divided into two groups as malignant (Group 1: Differentiated thyroid cancers) and benign (Group 2: Multinodular goiter). The groups were compared according to tissue localizations.

RESULTS

The TOS value of tumor edge was significantly higher than the values of tumor core and healthy thyroid tissue. The OSI value of tumor edge was significantly higher than the values of tumor core and healthy thyroid tissue. There was no significant difference between Group 1 and Group 2 in terms of TAS, TOS, and OSI values of tumor core. The OSI values in tumor edge and healthy thyroid tissue were significantly higher in Group 1 than in Group 2. There was no significant difference between the groups in terms of TAS and TOS values of tumor edge and healthy thyroid tissue.

CONCLUSION

The oxidative stress values of tumor edge were significantly higher than the tumor core and healthy thyroid tissue values. The oxidative stress values of tumor edge and healthy thyroid tissue were significantly higher in malignant thyroid tumors compared to benign thyroid tumors.

Redox Status and Antioxidative Cofactor Metals Influence Clinical and Pathological Characteristics of Papillary Thyroid Carcinoma and Colloid Goiter

Papillary thyroid carcinoma (PTC) is the endocrine neoplasm that occurs the most often worldwide, and its molecular pathophysiology is still not well characterized. Redox status is recognized as an important factor of carcinogenesis, but its influence on the PTC's clinical course needs to be better elucidated. The aim of this research was to determine the tissue redox status of 65 PTC and 45 colloid goiter (CG) patients together with antioxidative cofactor metal profiling. The malondialdehyde (MDA) concentration was used to access the prooxidation level, while antioxidant mechanisms were estimated by assaying the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR). The antioxidative cofactor metals included quantification of Se, Cu, Zn, and Mn concentration. PTC tissues had normal prooxidation levels and increased GPx and GR activity. The activity of SOD has been significantly reduced in multicentric PTC dissemination and increased in smokers. SOD activity was directly dependent on MDA levels in CG tissues. CG patients with retrosternal goiter had reduced MDA concentration and SOD activity. Numerous correlations between redox parameters in PTC tissues reveal good co-activation of antioxidative mechanisms and cooperative response on prooxidation. PTC tissues had decreased Se levels and increased concentration of Cu and Mn in comparison to other tissues. MDA concentration and SOD activity were significant predictors of PTC's multicentric dissemination and for the existence of lymph node metastases, respectively. Particularly, the concentration of Cu predicted the retrosternal localization in CG patients. Significant findings presented in this study provide a possibility for development of novel prognostic molecular biomarkers of PTC and CG.

Do Different Species of Sargassum in Haizao Yuhu Decoction Cause Different Effects in a Rat Goiter Model?

Sargassum species combined with Glycyrrhiza uralensis is a famous herbal pair in traditional Chinese medicine, as one of the so-called “eighteen antagonistic medicaments.” In the Chinese Pharmacopoeia, two different species of Sargassum, Sargassum pallidum and Sargassum fusiforme, are recorded but they are not clearly differentiated in clinical use. In this study, we aimed to determine whether the two species of Sargassum could result in different effects when combined with G. uralensis in Haizao Yuhu Decoction (HYD), which is used for treating thyroid-related diseases, especially goiter. HYD containing S. pallidum or S. fusiforme was administered to rats with propylthiouracil-induced goiter. After 4 weeks, pathological changes in the thyroid tissue and the relative thyroid weight indicated that HYD containing S. pallidum or S. fusiforme protected thyroid tissues from propylthiouracil damage. Neither species increased the propylthiouracil-induced decrease in serum levels of thyroid hormones. However, there were some differences in their actions, and only HYD containing S. fusiforme abated the propylthiouracil-induced elevation of serum thyroid-stimulating hormone levels and activated thyroglobulin mRNA expression.

Analyses of antioxidant status and nucleotide alterations in genes encoding antioxidant enzymes in patients with benign and malignant thyroid disorders

Background

Synthesis of thyroid hormones and regulation of their metabolism involve free radicals that may affect redox balance in the body. Thyroid disorders causing variations in the levels of thyroid hormones may alter cellular oxidative stress. The aim of this study was to measure the antioxidant activities and biomarkers of oxidative stress in serum and red blood cells (RBC) of patients with benign and malignant thyroid disorders and to investigate if changes in the antioxidant activities in these patients were linked to alterations in genes encoding the antioxidant enzymes.

Methods

Forty-one patients with thyroid disorders from University of Malaya Medical Centre were recruited. They were categorised into four groups: multinodular goitre (MNG) (n = 18), follicular thyroid adenoma (FTA) (n = 7), papillary thyroid cancer (PTC) (n = 10), and follicular thyroid cancer (FTC) (n = 6). Serum and RBC of patients were analysed for antioxidant activities, antioxidant enzymes, and biomarkers of oxidative stress. Alterations in genes encoding the antioxidant enzymes were analysed using whole exome sequencing and PCR–DNA sequencing.

Results

Patients with thyroid disorders had significantly higher serum superoxide dismutase (SOD) and catalase (CAT) activities compared to control, but had lower activities in RBC. There were no significant changes in serum glutathione peroxidase (GPx) activity. Meanwhile, GPx activity in RBC was reduced in PTC and FTC, compared to control and the respective benign groups. Antioxidant activities in serum were decreased in the thyroid disorder groups when compared to the control group. The levels of malondialdehyde (MDA) were elevated in the serum of FTA group when compared to controls, while in the RBC, only the MNG and PTC groups showed higher MDA equivalents than control. Serum reactive oxygen species (ROS) levels in PTC group of both serum and RBC were significantly higher than control group. Whole exome sequencing has resulted in identification of 49 single nucleotide polymorphisms (SNPs) in MNG and PTC patients and their genotypic and allelic frequencies were calculated. Analyses of the relationship between serum enzyme activities and the total SNPs identified in both groups revealed no correlation.

Discussion

Different forms of thyroid disorders influence the levels of antioxidant status in the serum and RBC of these patients, implying varying capability of preventing oxidative stress. A more comprehensive study with a larger target population should be done in order to further evaluate the relationships between antioxidant enzymes gene polymorphisms and thyroid disorders, as well as strengthening the minor evidences provided in literatures.

Papillary Thyroid Carcinoma: A Malignant Tumor with Increased Antioxidant Defense Capacity

Papillary thyroid carcinoma (PTC) is the commonest thyroid malignancy worldwide for which the radiation exposure is the most influential risk factor. The levels of oxidative stress in PTC are not well characterized on the tissue level. The objective of this study was to evaluate total oxidant status (TOS) and total antioxidant status (TAS) in PTC and benign goiter (BG) tissues and to examine their association with clinicopathological characteristics. Tumor and normal thyroid tissue samples were collected from 59 PTC patients, and goiter tissues were collected from 50 BG patients. TOS and TAS were quantified in the tissue homogenates by spectrophotometric assays. TOS values in tumor tissues did not differ significantly from normal and goiter tissues; however, PTC tissues have significantly higher TAS values than normal and goiter tissues. TOS values correlated with retrosternal growth in BG patients. The significant correlations were found between TOS and TAS values and thyroid function parameters. In 17 PTC patients with multiple tumor foci (multicentric phenotype), TAS values were significantly lower, compared to 42 patients with unicentric PTC. TAS and TOS are the most useful predictors of thyroid capsular invasion by PTC. The age, sex, body mass index, smoking, familial history of thyroid disease and nodule size did not influence TOS and TAS in PTC or BG patients. In conclusion, we show the profiles of TOS and TAS in PTC and BG tissues. Importantly, PTC tissues possess increased antioxidant capacity. The redox status influences the parameters of the thyroid function and tumor's biological behavior.