The miR-146b-3p/PAX8/NIS Regulatory Circuit Modulates the Differentiation Phenotype and Function of Thyroid Cells during Carcinogenesis

MicroRNA-146 family: Molecular insights into their role in regulation of signaling pathways in glioma progression

Glioma is a highly lethal brain cancer in humans. Despite advancements in treatment, the prognosis for patients remains unfavorable. Epigenetic factors, along with their interactions and non-coding RNAs (ncRNAs), are crucial in glioma cells' development and aggressive characteristics. MicroRNAs (miRNAs) are a class of small non-coding RNAs (ncRNAs) that modulate the expression of various genes by binding to target mRNA molecules. They play a critical role in regulating essential biological mechanisms such as cell proliferation and differentiation, cell cycle, and apoptosis. MiR-146a/miR-146b is a significant and prevalent miRNA whose expression alterations are linked to various pathological changes in cancer cells, as well as the modulation of several cellular signaling pathways, including NF-κB, TGF-β, PI3K/Akt, and Notch-1. Scientists may identify novel targets in clinical settings by studying the complicated link between Mir-146a/mir-146b, drug resistance, molecular pathways, and pharmacological intervention in gliomas. Additionally, its interactions with other ncRNAs, such as circular RNA and long non-coding RNA, contribute to the pathogenesis of glioma. As well as miR-146 holds potential as both a diagnostic and therapeutic biomarker for patients with this condition. In the current review, we investigate the significance of miRNAs in the context of glioma, with a particular focus on the critical role of Mir-146a/mir-146b in glioma tumors. Additionally, we examined the clinical relevance of this miRNA, highlighting its potential implications for diagnosis and treatment.

Pathogenesis and Management Strategies in Radioiodine-Refractory Differentiated Thyroid Cancer: From Molecular Mechanisms Toward Therapeutic Approaches: A Comprehensive Review

Thyroid cancer (TC) remains the most common cancer in endocrinology. Differentiated thyroid cancer (DTC), the most common type of TC, generally has a favorable outlook with conventional treatment, which typically includes surgery along with radioiodine (RAI) therapy and thyroid-stimulating hormone (TSH) suppression through thyroid hormone therapy. However, a small subset of patients (less than 5%) develop resistance to RAI. This resistance occurs due to the loss of Na/I symporter (NIS) activity, which is crucial for iodine absorption in thyroid cells. The decline in NIS activity appears to be due to gene modifications, reconfigurations with irregular stimulation of signaling pathways such as MAPK and PI3K/Akt pathways. These molecular changes lead to a diminished ability of DTC cells to concentrate iodine, which makes RAI therapy ineffective. As a consequence, patients with radioiodine-refractory DTC require alternative treatments. Therapy with tyrosine kinase inhibitors (TKIs) has emerged as the primary treatment option to inhibit proliferation and growth of RAIR-DTC, targeting the pathways responsible for tumor progression. In this article, we analyze molecular processes responsible for RAI resistance and explore both conventional and emerging therapeutic strategies for managing RAIR-DTC, aiming to improve patient outcomes.

The Role of miRNA in Hyperthyroidism Induced by Excessive Iodine in Drinking Water

In recent years, iodine deficiency-related diseases have been effectively controlled; the prevalence of excessive iodine-induced thyroid diseases has increased, such as hyperthyroidism. However, there are still several controversial outcomes regarding the relationship between excessive iodine intakes and hyperthyroidism. MicroRNAs (miRNAs) extensively participate in the progression of thyroid diseases; nevertheless, the relationship and mechanism between iodine exposure and miRNAs have not been explored in hyperthyroidism patients. In this study, a total of 308 pairs of hyperthyroidism patients and healthy controls were enrolled in. Logistic regression analysis showed that level of water iodine >100 μg/L was an independent risk factor for hyperthyroidism. Compared with the healthy control, the serum thyroglobulin (Tg) content and levels of interferon-γ (IFN-γ), interleukin 6 (IL-6), and tumor necrosis factor-α (TNF-α) were significantly elevated in hyperthyroidism patients. Further, high-throughput miRNA sequencing was applied to find crucial miRNAs involved in the occurrence of hyperthyroidism related to excessive water iodine. Based on the fold change and Q value, miR-144-3p, miR-204-5p, miR-346, miR-23b-5p, and miR-193b-3p were selected for validation by qRT-PCR. Our results showed that miR-346 and miR-204-5p in the case group were significantly lower than those of the control group, and the similar results found under the level of water iodine >300 μg/L. Nonetheless, no significant difference was found at 10-100 μg/L level of water iodine. Furthermore, the ROC curve indicated that miR-346 and miR-204-5p had the ability to diagnose hyperthyroidism patients. Taken together, excessive water iodine may decrease the expression of miR-346 and miR-204-5p, which mediate the elevation of Tg and cytokines, ultimately making contribution to the development of hyperthyroidism.

DLK1-DIO3 region as a source of tumor suppressor miRNAs in papillary thyroid carcinoma

BACKGROUND

In previous studies, we demonstrated the downregulation of several miRNAs from the DLK1-DIO3 genomic region in papillary thyroid carcinoma (PTC). Due to the large number of miRNAs within this region, the individual contribution of these molecules to PTC development and progression remains unclear.

OBJECTIVE

In this study, we aimed to clarify the contribution of DLK1-DIO3-derived miRNAs to PTC.

METHODS

We used different computational approaches and in vitro resources to assess the biological processes and signaling pathways potentially modulated by these miRNAs.

RESULTS

Our analysis suggests that, out of more than 100 mature miRNAs originated from the DLK1-DIO3 region, a set of 12 miRNAs accounts for most of the impact on PTC development and progression, cooperating to modulate distinct cancer-relevant biological processes, such as cell migration, extracellular matrix remodeling, and signal transduction. The restoration of the expression of one of these miRNAs (miR-485-5p) in a BRAFT199A-positive PTC cell line impaired proliferation and migration, suppressing the expression of GAB2 and RAC1, validated miR-485-5p targets.

CONCLUSIONS

Overall, our results shed light on the role of the DLK1-DIO3 region, which harbors promising tumor suppressor miRNAs in thyroid cancer, and open prospects for the functional exploration of these miRNAs as therapeutic targets for PTC.

An Unlikely Source of Iodine Uptake: A Bronchogenic Cyst Masquerading as Metastatic Thyroid Cancer

Radioactive iodine therapy and posttreatment scanning are essential components of differentiated thyroid carcinoma treatment and detection of metastatic disease. False-positive results can be seen on an I-131 scan and are important for clinicians to be aware of. Here, we present a case of a 33-year-old female with follicular thyroid carcinoma who was noted to have an area of moderate uptake in the chest on a whole-body scan following remnant ablation with 30 mCi of I-131 (1.11GBq) concerning for a metastatic hilar lymph node. This was determined to be a mediastinal bronchogenic cyst on surgical pathology. It has been previously proposed that the expression of sodium iodide symporters in some bronchogenic cysts could be the mechanism by which iodine uptake is seen within them. We were able to demonstrate positive immunohistochemical staining for both sodium iodide symporter and the associated paired box gene 8 transcription factor in the cyst sample, which supports the proposed theory.

The Role of Thyroid Hormone Synthesis Gene-Related miRNAs Profiling in Structural and Functional Changes of The Thyroid Gland Induced by Excess Iodine

At recent years, the impairment caused by iodine excess are paid more attention. However, there is still largely unknown about the exact mechanism induced by excessive iodine. MiRNAs have been found to act as biomarkers for a variety of diseases, whereas fewer studies focused on miRNAs related to a cluster of genes regulating thyroid hormone synthesis, such as NIS, Pendrin, TPO, MCT8, TSHR, TSHα, and TSHβ-related miRNAs in structural and functional changes of the thyroid gland induced by subchronic and chronic high iodine exposure. In the present study, one hundred and twenty 4-week-old female Wistar rats were randomly divided into control group (I50µg/L KIO3); HI 1 (I6000µg/L KIO3); HI 2 (I10000µg/L KIO3); and HI 3 (I50000µg/L KIO3), the exposure period was 3 months and 6 months, respectively. The iodine contents in the urine and blood, thyroid function, and pathological changes were determined. In addition, levels of thyroid hormone synthesis genes and the associated miRNAs profiling were detected. The results showed that subclinical hypothyroidism occurred in the high iodine groups with subchronic high iodine exposure, while 6-month exposure led to hypothyroidism in the I10000µg/L and I50000µg/L groups. Subchronic and chronic high iodine exposure caused mRNA and protein levels of NIS, TPO, and TSHR decreased significantly, and Pendrin expression increased significantly. In addition, MCT8 mRNA and protein levels are only remarkably decreased under the subchronic exposure. PCR results showed that levels of miR-200b-3p, miR-185-5p, miR-24-3p, miR-200a-3p, and miR-25-3p increased significantly exposed to high iodine for 3 months, while miR-675-5p, miR-883-5p, and miR-300-3p levels increased significantly under the exposure to high iodine for 6 months. In addition, miR-1839-3p level was markedly decreased exposed to high iodine for 3 and 6 months. Taken together, the miRNA profiling of genes regulating thyroid hormone synthesis remarkably altered from subclinical hypothyroidism to hypothyroidism induced by excess iodine exposure, and some miRNAs may play an important role in subclinical hypothyroidism or hypothyroidism through regulating NIS, Pendrin, TPO, MCT8, and TSHR providing promising targets to alleviate the impairment on the structure and function of thyroid gland.

The miR-146b-3p/TNFAIP2 axis regulates cell differentiation in acute myeloid leukaemia

Our purpose is to verify that miR-146b-3p targets the downstream transcript TNFAIP2 in order to reveal the machinery underlying the miR-146b-3p/TNFAIP2 axis regulating acute myeloid leukaemia (AML) differentiation. Bioinformatics analyses were performed using multiple databases and R packages. The CD11b+ and CD14+ cell frequencies were detected using flow cytometry and immunofluorescence staining. The TNFAIP2 protein expression was evaluated using western blotting, immunocytochemistry and immunofluorescence staining. The qRT-PCR was conducted to detect the expression of TNFAIP2 and miR-146b-3p. TNFAIP2 and its correlated genes were enriched in multiple cell differentiation pathways. TNFAIP2 was upregulated upon leukaemic cell differentiation. miR-146b-3p directly targeted TNFAIP2, resulting in a decrease in TNFAIP2 expression. Forced expression of TNFAIP2 or knockdown of miR-146b-3p significantly induced the differentiation of MOLM-13 cells. In this study, we demonstrated that TNFAIP2 is a critical driver in inducing differentiation and that the miR-146b-3p/TNFAIP2 axis involves in regulating cell differentiation in AML.

Radioiodine-refractory differentiated thyroid cancer: Molecular mechanisms and therapeutic strategies for radioiodine resistance

Radioiodine-refractory differentiated thyroid cancer (RAIR-DTC) is difficult to treat with radioactive iodine because of the absence of the sodium iodide transporter in the basement membrane of thyroid follicular cells for iodine uptake. This is usually due to the mutation or rearrangement of genes and the aberrant activation of signal pathways, which result in abnormal expression of thyroid-specific genes, leading to resistance of differentiated thyroid cancer cells to radioiodine therapy. Therefore, inhibiting the proliferation and growth of RAIR-DTC with multikinase inhibitors and other drugs or restoring its differentiation and then carrying out radioiodine therapy have become the first-line treatment strategies and main research directions. The drugs that regulate these kinases or signaling pathways have been studied in clinical and preclinical settings. In this review, we summarized the major gene mutations, gene rearrangements and abnormal activation of signaling pathways that led to radioiodine resistance of RAIR-DTC, as well as the medicine that have been tested in clinical and preclinical trials.

CircGLIS3 inhibits thyroid cancer invasion and metastasis through miR-146b-3p/AIF1L axis

PURPOSE

Studies have shown that circRNA is involved in the occurrence and development of human cancers. However, it remains unclear that the contribution of circRNA in thyroid carcinoma and its role in the process of tumorigenesis.

METHODS

The expression profile of circRNA-miRNA-mRNA in thyroid carcinoma was detected by RNA sequencing and verified by qRT-PCR. The characteristics of circGLIS3 were verified by RNase R and actinomycin assays, subcellular fractionation, and fluorescence in situ hybridization. The functions of circGLIS3 and AIF1L were detected by wound healing, transwell, 3D culture and Western blot. RNA Immunoprecipitation (RIP), RNA pulldown and dual-luciferase reporter assays were used to verify the target genes of circGLIS3 and downstream miRNAs. Functional rescue experiments were performed by transfecting miRNA mimics or siRNA of target genes. Finally, metastatic mouse models were used to investigate circGLIS3 function in vivo.

RESULTS

In this study, we discovered a novel circRNA (has_circ_0007368, named as circGLIS3) by RNA sequencing. CircGLIS3 was down-regulated in thyroid carcinoma tissues and cells line, and was negatively associated with malignant clinical features of thyroid carcinoma. Functional studies found that circGLIS3 could inhibit the migration and invasion of thyroid carcinoma cells, and was related to the EMT process. Mechanistically, circGLIS3 can upregulate the expression of the AIF1L gene by acting as a miR-146b-3p sponge to inhibit the progression of thyroid carcinoma.

CONCLUSION

Our study identified circGLIS3 as a novel tumor suppressor in thyroid cancer, indicating the potential of circGLIS3 as a promising diagnostic and prognostic marker for thyroid cancer.

BRAF, TERT and HLA-G Status in the Papillary Thyroid Carcinoma: A Clinicopathological Association Study

As BRAF, TERT, HLA-G, and microRNAs have been individually associated with papillary thyroid carcinoma (PTC), we aimed to evaluate the individual and collaborative role of these markers in PTC in the same patient cohort. HLA-G and BRAF tumor expression was evaluated by immunohistochemistry. Using molecular methods, BRAFV600E and TERT promoter mutations were evaluated in thyroid fine needle aspirates. MicroRNA tumor profiling was investigated using massively parallel sequencing. We observed strong HLA-G (67.96%) while BRAF (62.43%) staining was observed in PTC specimens. BRAF overexpression was associated with poor response to therapy. The BRAFV600E (52.9%) and TERTC228T (13%) mutations were associated with extrathyroidal extension, advanced-age, and advanced-stage cancer. The TERT rs2853669 CC+TC genotypes (38%) were overrepresented in metastatic tumors. Nine modulated microRNAs targeting the BRAF, TERT, and/or HLA-G genes were observed in PTC and involved with cancer-related signaling pathways. The markers were individually associated with PTC features, emphasizing the synergistic effect of BRAFV600E and TERTC228T; however, their collaborative role on PTC outcome was not fully demonstrated. The differentially expressed miRNAs targeting the BRAF and/or HLA-G genes may explain their increased expression in the tumor milieu.

Advances in the molecular mechanism and targeted therapy of radioactive-iodine refractory differentiated thyroid cancer

Most patients with differentiated thyroid cancer have a good prognosis after radioactive iodine-131 treatment, but there are still a small number of patients who are not sensitive to radioiodine treatment and may subsequently show disease progression. Therefore, radioactive-iodine refractory differentiated thyroid cancer treated with radioiodine usually shows reduced radioiodine uptake. Thus, when sodium iodine symporter expression, basolateral membrane localization and recycling degradation are abnormal, radioactive-iodine refractory differentiated thyroid cancer may occur. In recent years, with the deepening of research into the pathogenesis of this disease, an increasing number of molecules have become or are expected to become therapeutic targets. The application of corresponding inhibitors or combined treatment regimens for different molecular targets may be effective for patients with advanced radioactive-iodine refractory differentiated thyroid cancer. Currently, some targeted drugs that can improve the progression-free survival of patients with radioactive-iodine refractory differentiated thyroid cancer, such as sorafenib and lenvatinib, have been approved by the FDA for the treatment of radioactive-iodine refractory differentiated thyroid cancer. However, due to the adverse reactions and drug resistance caused by some targeted drugs, their application is limited. In response to targeted drug resistance and high rates of adverse reactions, research into new treatment combinations is being carried out; in addition to kinase inhibitor therapy, gene therapy and rutin-assisted iodine-131 therapy for radioactive-iodine refractory thyroid cancer have also made some progress. Thus, this article mainly focuses on sodium iodide symporter changes leading to the main molecular mechanisms in radioactive-iodine refractory differentiated thyroid cancer, some targeted drug resistance mechanisms and promising new treatments.

Sesamin alleviated fluoride - induced thyroid endocrine disruption in zebrafish (Danio rerio)

Previous studies have indicated that fluoride could induce the damage of thyroid. However, the effects of sesamin on thyroid endocrine function in zebrafish exposed to fluoride have not been clarified. This study was designed to investigate the alleviating effects of sesamin on thyroid endocrine disruption in zebrafish induced by fluoride. The results showed that sesamin significantly improved growth performance in adults exposed to fluoride; decreased significantly the mortality rate, increased remarkably the hatching rate and body length, and alleviated the phenomenon of spinal curvature, yolk cyst and pericardial cyst to varying degrees in fluoride-exposed embryos and larvae. Sesamin alleviated remarkably the damage of thyroid tissues in fluoride-exposed adults. Moreover, sesamin obviously reduced oxidative stress and improved the imbalance of thyroid hormones in fluoride-exposed adults or larvae. In addition, sesamin reversed the expression of endocrine-related genes of thyroid in fluoride-exposed adults or larvae. This indicates that sesamin can affects the thyroid tissue structure, hormone levels, and the expression of endocrine-related genes of thyroid, thus alleviating the thyroid endocrine disorder induced by fluoride and improving the growth and development. This study also demonstrates that sesamin can be a promising novel treatment for thyroid endocrine disorder caused by fluoride.

Epigenetic Targets and Their Inhibitors in Thyroid Cancer Treatment

Although biologically targeted therapies based on key oncogenic mutations have made significant progress in the treatment of locally advanced or metastatic thyroid cancer, the challenges of drug resistance are urging us to explore other potentially effective targets. Herein, epigenetic modifications in thyroid cancer, including DNA methylation, histone modifications, non-coding RNAs, chromatin remodeling and RNA alterations, are reviewed and epigenetic therapeutic agents for the treatment of thyroid cancer, such as DNMT (DNA methyltransferase) inhibitors, HDAC (histone deacetylase) inhibitors, BRD4 (bromodomain-containing protein 4) inhibitors, KDM1A (lysine demethylase 1A) inhibitors and EZH2 (enhancer of zeste homolog 2) inhibitors, are updated. We conclude that epigenetics is promising as a therapeutic target in thyroid cancer and further clinical trials are warranted.

Radioiodine therapy in advanced differentiated thyroid cancer: Resistance and overcoming strategy

Thyroid cancer is the most prevalent endocrine tumor and its incidence is fast-growing worldwide in recent years. Differentiated thyroid cancer (DTC) is the most common pathological subtype which is typically curable with surgery and Radioactive iodine (RAI) therapy (approximately 85%). Radioactive iodine is the first-line treatment for patients with metastatic Papillary Thyroid Cancer (PTC). However, 60% of patients with aggressive metastasis DTC developed resistance to RAI treatment and had a poor overall prognosis. The molecular mechanisms of RAI resistance include gene mutation and fusion, failure to transport RAI into the DTC cells, and interference with the tumor microenvironment (TME). However, it is unclear whether the above are the main drivers of the inability of patients with DTC to benefit from iodine therapy. With the development of new biological technologies, strategies that bolster RAI function include TKI-targeted therapy, DTC cell redifferentiation, and improved drug delivery via extracellular vesicles (EVs) have emerged. Despite some promising data and early success, overall survival was not prolonged in the majority of patients, and the disease continued to progress. It is still necessary to understand the genetic landscape and signaling pathways leading to iodine resistance and enhance the effectiveness and safety of the RAI sensitization approach. This review will summarize the mechanisms of RAI resistance, predictive biomarkers of RAI resistance, and the current RAI sensitization strategies.

EIF4A3-Induced Upregulation of hsa_circ_0040039 is a Biomarker and Aggravates IL-1β-Stimulated Intervertebral Disc Degeneration

Intervertebral disc degeneration (IDD) is characterised by nucleus pulposus (NP) loss and extracellular matrix (ECM) degeneration. Circular RNAs (circRNAs) have been reported to be dysregulated during IDD progression. Recently, reports showed that hsa_circ_0040039 was increased in degenerated lumbar disc samples. The aim of this study was to explore the specific role and underlying mechanisms of hsa_circ_0040039 in IDD. The expression of hsa_circ_0040039 was investigated in NP tissues of IDD patients. IL-1β was used to treat NP cells to construct an IDD in vitro model. Overexpression and loss-of-function assays and bioinformatic analysis were performed to evaluate the role and potential mechanism of hsa_circ_0040039 during IDD progression. Hsa_circ_0040039 expression was increased about 2 folds in NP tissues compared with normal tissues and IL-1β-stimulated NP cells also presented hsa_circ_0040039 upregulation, and its overexpression promoted cell proliferation and ECM degeneration. The depletion of hsa_circ_0040039 had the opposite effects. Based on bioinformatics prediction, Luciferase assay, PCR and Western blot, our study verified that hsa_circ_0040039 directly bond to miR-146b-3p, then mediated its targeted MMP2 and PCNA. Moreover, the overexpression of miR-146b-3p and the silence of MMP2 or PCNA, partially abolished the effect of hsa_circ_0040039 on IL-1β-stimulated NPs. Hsa_circ_0040039 may participate in IDD development by mediating the repair and regeneration of NPs through upregulation MMP2 and PCNA mediated by miR-146b-3p.

The potential interaction between medical treatment and radioiodine treatment success: A systematic review

Introduction

Radioactive iodine (RAI) therapy is a critical component in the post-surgical management of thyroid cancer patients, as well as being a central therapeutic option in the treatment of hyperthyroidism. Previous work suggests that antithyroid drugs hinder the efficacy of RAI therapy in patients. However, the effects of other background medications on RAI treatment efficacy have not been evaluated. Therefore, we performed a systematic review and meta-analysis investigating the potential off-target effects of medication on RAI therapy in patients with thyroid cancer and hyperthyroidism.

Methods

Systematic review and meta-analysis according to the 2020 PRISMA guidelines. Databases searched: MEDLINE, EMBASE and Cochrane Library for studies published between 2001 and 2021.

Results

Sixty-nine unique studies were identified. After screening, 17 studies with 3313 participants were included. One study investigated thyroid cancer, with the rest targeted to hyperthyroidism. The majority of studies evaluated the effects of antithyroid drugs; the other drugs studied included lithium, prednisone and glycididazole sodium. Antithyroid drugs were associated with negative impacts on post-RAI outcomes (n = 5 studies, RR = 0.81, p = 0.02). However, meta-analysis found moderate heterogeneity between studies (I2 = 51%, τ2 = 0.0199, p = 0.08). Interestingly, lithium (n = 3 studies), prednisone (n = 1 study) and glycididazole (n = 1 study) appeared to have positive impacts on post-RAI outcomes upon qualitative analysis.

Conclusion

Our systematic review strengthens previous work on antithyroid medication effects on RAI, and highlights that this field remains under researched especially for background medications unrelated to thyroid disease, with very few papers on non-thyroid medications published.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php, identifier CRD42021274026.

Genomic and epigenomic profile of thyroid cancer

Thyroid cancer is the most common malignancy of the endocrine system, and its incidence has been steadily increasing. Advances in sequencing have allowed analysis of the entire cancer genome, and has provided new information on the genetic lesions and modifications responsible for the onset, progression, dedifferentiation and metastasis of thyroid carcinomas. Moreover, integrated genomics has advanced our understanding of the development of cancer and its behavior, and has facilitated the identification of new genetic mutations and molecular pathways. The functional analysis of epigenetic modifications, such as DNA methylation, histone acetylation and non-coding RNAs, have contributed to define new regulatory mechanisms that control cell malignancy in thyroid cancer, especially aggressive forms. Here we review the most recent advances in genomics and epigenomics of thyroid cancer, which have resulted in a new classification and interpretation of the initiation and progression of thyroid tumors, providing new tools and opportunities for further investigation and for the clinical development of new treatment strategies.

Modulatory role of miRNAs in thyroid and breast cancer progression and insights into their therapeutic manipulation

Over the past few decades, thyroid cancer has become one of the most common types of endocrine cancer, contributing to an increase in prevalence. In the year 2020, there were 586,202 newly diagnosed cases of thyroid cancer around the world. This constituted approximately 3.0% of all patients diagnosed with cancer. The World Health Organization reported that there will be 2.3 million women receiving treatment for breast cancer in 2020, with 685,000. Despite the fact that carcinoma is one of the world's leading causes of death, there is still a paucity of information about its biology. MicroRNAs (miRNAs; miRs) are non-coding RNAs that can reduce gene expression by cleaving the 3' untranslated regions of mRNA. These factors make them a potential protein translation inhibitor. Diverse biological mechanisms implicated in the genesis of cancer are modulated by miRNA. The investigation of global miRNA expression in cancer showed regulatory activity through up regulation and down-regulation in several cancers, including thyroid cancer and breast cancer. In thyroid cancer, miRNA influences several cancers related signaling pathways through modulating MAPK, PI3K, and the RAS pathway. In breast cancer, the regulatory activity of miRNA was played through the cyclin protein family, protein kinases and their inhibitors, and other growth promoters or suppressors, which modulated cell proliferation and cell cycle progression. This article's goal is to discuss key miRNA expressions that are involved in the development of thyroid and breast cancer as well as their therapeutic manipulation for these two specific cancer types.

C1QTNF6 regulated by miR-29a-3p promotes proliferation and migration in stage I lung adenocarcinoma

OBJECTIVE

C1QTNF6 has been implicated as an essential component in multiple cellular and molecular preliminary event, including inflammation, glucose metabolism, endothelial cell modulation and carcinogenesis. However, the biological process and potential mechanism of C1QTNF6 in lung adenocarcinoma (LUAD) are indefinite and remain to be elucidated. Therefore, we investigated the interaction among the traits of C1QTNF6 and LUAD pathologic process.

METHODS

RT-qPCR and western blot were conducted to determine the expression levels of C1QTNF6. RNA interference and overexpression of C1QTNF6 were constructed to identify the biological function of C1QTNF6 in cellular proliferative, migratory and invasive potentials in vitro. Dual-luciferase reporter assay was applied to identify the possible interaction between C1QTNF6 and miR-29a-3p. Moreover, RNA sequencing analysis of C1QTNF6 knockdown was performed to identify the potential regulatory pathways.

RESULTS

C1QTNF6 was upregulated in stage I LUAD tissues compared with adjacent non-cancerous tissues. Concurrently, C1QTNF6 knockdown could remarkably inhibit cell proliferation, migratory and invasive abilities, while overexpression of C1QTNF6 presented opposite results. Additionally, miR-29a-3p may serve as an upstream regulator of C1QTNF6 and reduce the expression of C1QTNF6. Subsequent experiments showed that miR-29a-3p could decrease the cell mobility and proliferation positive cell rates, as well as reduce the migratory and invasive possibilities in LUAD cells via downregulating C1QTNF6. Moreover, RNA sequencing analysis demonstrated that the cytokine-cytokine receptor interaction pathway may participate in the process of C1QTNF6 regulating tumor progression.

CONCLUSION

Our study first demonstrated that downregulation of C1QTNF6 could inhibit tumorigenesis and progression in LUAD cells negatively regulated by miR-29a-3p. These consequences could reinforce our awareness and understanding of the underlying mechanism and provide a promising therapeutic target for LUAD.

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.

Identification of an interactome network between lncRNAs and miRNAs in thyroid cancer reveals SPTY2D1-AS1 as a new tumor suppressor

Thyroid cancer is the most common primary endocrine malignancy in adults and its incidence is rapidly increasing. Long non-coding RNAs (lncRNAs), generally defined as RNA molecules longer than 200 nucleotides with no protein-encoding capacity, are highly tissue-specific molecules that serve important roles in gene regulation through a variety of different mechanisms, including acting as competing endogenous RNAs (ceRNAs) that ‘sponge’ microRNAs (miRNAs). In the present study, using an integrated approach through RNA-sequencing of paired thyroid tumor and non-tumor samples, we have identified an interactome network between lncRNAs and miRNAs and examined the functional consequences in vitro and in vivo of one of such interactions. We have identified a likely operative post-transcriptional regulatory network in which the downregulated lncRNA, SPTY2D1-AS1, is predicted to target the most abundant and upregulated miRNAs in thyroid cancer, particularly miR-221, a well-known oncomiRNA in cancer. Indeed, SPTY2D1-AS1 functions as a potent tumor suppressor in vitro and in vivo, it is downregulated in the most advanced stages of human thyroid cancer, and it seems to block the processing of the primary form of miR-221. Overall, our results link SPTY2D1-AS1 to thyroid cancer progression and highlight the potential use of this lncRNA as a therapeutic target of thyroid cancer.

Circulating MicroRNA Profiles as Potential Biomarkers for Differentiated Thyroid Cancer Recurrence

CONTEXT

Circulating microRNAs (miRNAs) are emerging biomarkers of thyroid cancer.

OBJECTIVE

This study sought to identify the profile of circulating miRNAs and its response to human recombinant TSH (rhTSH) in thyroid cancer patients with recurrent/persistent disease.

METHODS

We obtained serum samples from 30 patients with differentiated thyroid cancer, 14 with recurrent/persistent disease and 16 with complete remission. We used next-generation sequencing to define the miRnomes along with a comprehensive quantitative PCR (qPCR) validation using 2 different platforms. We made a transversal study by comparing serum miRNA profiles of patients with or without recurrent/persistent disease and a longitudinal study looking at differences before and after rhTSH stimulation. Selected miRNAs were then studied in human thyroid cancer cell lines TPC-1, FTC-133, and OCUT-2 in response to TSH stimulation.

RESULTS

We could not demonstrate any consistent differences in serum profiles of known miRNAs between patients with and without recurrent/persistent disease or before and after rhTSH stimulation. However, our sequencing data revealed 2 putative novel miRNAs that rise with rhTSH stimulation in the serums of patients with recurrent/persistent disease. We further confirmed by qPCR the upregulation of these putative miRNAs both in serums and in TSH-stimulated cells. We also show miRNAs that are good candidates for housekeeping genes in the serum of patients independently of the levels of TSH.

CONCLUSIONS

The present study does not provide evidence that known miRNAs can be used as circulating markers for recurrence of thyroid cancer. However, we suggest that novel miRNA molecules may be related to thyroid cancer pathogenesis.

Targeting non-canonical pathways as a strategy to modulate the sodium iodide symporter

The sodium iodide symporter (NIS) functions to transport iodide and is critical for successful radioiodide ablation of cancer cells. Approaches to bolster NIS function and diminish recurrence post-radioiodide therapy are impeded by oncogenic pathways that suppress NIS, as well as the inherent complexity of NIS regulation. Here, we utilize NIS in high-throughput drug screening and undertake rigorous evaluation of lead compounds to identify and target key processes underpinning NIS function. We find that multiple proteostasis pathways, including proteasomal degradation and autophagy, are central to the cellular processing of NIS. Utilizing inhibitors targeting distinct molecular processes, we pinpoint combinatorial drug strategies giving robust >5-fold increases in radioiodide uptake. We also reveal significant dysregulation of core proteostasis genes in human tumors, identifying a 13-gene risk score classifier as an independent predictor of recurrence in radioiodide-treated patients. We thus propose and discuss a model for targetable steps of intracellular processing of NIS function.

Comprehensive Analysis of the Prognosis and Drug Sensitivity of Differentiation-Related lncRNAs in Papillary Thyroid Cancer

Dedifferentiation is the main concern associated with radioactive iodine (RAI) refractoriness in patients with papillary thyroid cancer (PTC), and the underlying mechanisms of PTC dedifferentiation remain unclear. The present work aimed to identify a useful signature to indicate dedifferentiation and further explore its role in prognosis and susceptibility to chemotherapy drugs. A total of five prognostic-related DR-lncRNAs were selected to establish a prognostic-predicting model, and corresponding risk scores were closely associated with the infiltration of immune cells and immune checkpoint blockade. Moreover, we built an integrated nomogram based on DR-lncRNAs and age that showed a strong ability to predict the 3- and 5-year overall survival. Interestingly, drug sensitivity analysis revealed that the low-risk group was more sensitive to Bendamustine and TAS-6417 than the high-risk group. In addition, knockdown of DR-lncRNAs (DPH6-DT) strongly promoted cell proliferation, invasion, and migration via PI3K-AKT signal pathway in vitro. Furthermore, DPH6-DT downregulation also increased the expression of vimentin and N-cadherin during epithelial-mesenchymal transition. This study firstly confirms that DR-lncRNAs play a vital role in the prognosis and immune cells infiltration in patients with PTC, as well as a predictor of the drugs' chemosensitivity. Based on our results, DR-lncRNAs can serve as a promising prognostic biomarkers and treatment targets.

Targeting the Highly Expressed microRNA miR-146b with CRISPR/Cas9n Gene Editing System in Thyroid Cancer

Thyroid cancer is the most common endocrine malignancy, and the characterization of the genetic alterations in coding-genes that drive thyroid cancer are well consolidated in MAPK signaling. In the context of non-coding RNAs, microRNAs (miRNAs) are small non-coding RNAs that, when deregulated, cooperate to promote tumorigenesis by targeting mRNAs, many of which are proto-oncogenes and tumor suppressors. In thyroid cancer, miR-146b-5p is the most overexpressed miRNA associated with tumor aggressiveness and progression, while the antisense blocking of miR-146b-5p results in anti-tumoral effect. Therefore, inactivating miR-146b has been considered as a promising strategy in thyroid cancer therapy. Here, we applied the CRISPR/Cas9n editing system to target the MIR146B gene in an aggressive anaplastic thyroid cancer (ATC) cell line. For that, we designed two single-guide RNAs cloned into plasmids to direct Cas9 nickase (Cas9n) to the genomic region of the pre-mir-146b structure to target miR-146b-5p and miR-146b-3p sequences. In this plasmidial strategy, we cotransfected pSp-Cas9n-miR-146b-GuideA-puromycin and pSp-Cas9n-miR-146b-GuideB-GFP plasmids in KTC2 cells and selected the puromycin resistant + GFP positive clones (KTC2-Cl). As a result, we observed that the ATC cell line KTC2-Cl1 showed a 60% decrease in the expression of miR-146b-5p compared to the control, also showing reduced cell viability, migration, colony formation, and blockage of tumor development in immunocompromised mice. The analysis of the MIR146B edited sequence shows a 5 nt deletion in the miR-146b-5p region and a 1 nt deletion in the miR-146b-3p region in KTC2-Cl1. Thus, we developed an effective CRISPR/Cas9n system to edit the MIR146B miRNA gene and reduce miR-146b-5p expression which constitutes a potential molecular tool for the investigation of miRNAs function in thyroid cancer.

MiR-181a-5p Regulates NIS Expression in Papillary Thyroid Carcinoma

NIS is a potent iodide transporter encoded by the SLC5A5 gene. Its expression is reduced in papillary thyroid carcinoma (PTC). In this study we analyzed the impact of miR-181a-5p on NIS expression in the context of PTC. We used real-time PCR to analyze the expression of SLC5A5 and miR-181a-5p in 49 PTC/normal tissue pairs. Luciferase assays and mutagenesis were performed to confirm direct binding of miR-181a-5p to the 3′UTR of SLC5A5 and identify the binding site. The impact of modulation of miR-181a-5p using appropriate plasmids on endogenous NIS and radioactive iodine accumulation was verified. We confirmed downregulation of SLC5A5 and concomitant upregulation of miR-181a-5p in PTC. Broadly used algorithms did not predict the binding site of miR-181a-5p in 3′UTR of SLC5A5, but we identified and confirmed the binding site through mutagenesis using luciferase assays. In MCF7 and HEK293-flhNIS cell lines, transfection with mir-181a-expressing plasmid decreased endogenous SLC5A5, whereas silencing of miR-181a-5p increased it. We observed similar tendencies in protein expression and radioactive iodine accumulation. This study shows for the first time that miR-181a-5p directly regulates SLC5A5 expression in the context of PTC and may decrease efficacy of radioiodine treatment. Accordingly, miR-181a-5p may serve as an emerging target to enhance the efficacy of radioactive iodine therapy.

A Positive Feedback Loop Between DICER1 and Differentiation Transcription Factors Is Important for Thyroid Tumorigenesis

Background: DICER1 plays a central role in microRNA biogenesis and functions as a tumor suppressor in thyroid cancer, which is the most frequent endocrine malignancy with a rapidly increasing incidence. Thyroid cancer progression is associated with loss of cell differentiation and reduced expression of thyroid differentiation genes and response to thyrotropin (TSH). Here we investigated whether a molecular link exists between DICER1 and thyroid differentiation pathways. Methods: We used bioinformatic tools to search for transcription factor binding sites in the DICER1 promoter. DICER1, NKX2-1, PAX8, and CREB expression levels were evaluated by gene and protein expression in vitro and by interrogation of The Cancer Genome Atlas (TCGA) thyroid cancer data. Transcription factor binding and activity were assayed by chromatin immunoprecipitation, band-shift analysis, and promoter-reporter gene activity. Gene-silencing and overexpression approaches were used to elucidate the functional link between DICER1 and differentiation. Results: We identified binding sites for NKX2-1 and CREB within the DICER1 promoter and found that both transcription factors are functional in thyroid cells. TSH induced DICER1 expression in differentiated thyroid cells, at least in part, through the cAMP/PKA/CREB pathway. TCGA analysis revealed a significant positive correlation between CREB and DICER1 expression in human thyroid tumors. NKX2-1 overexpression increased DICER1 promoter activity and expression in vitro, and this was significantly greater in the presence of CREB and/or PAX8. Gain- and loss-of-function assays revealed that DICER1 regulates NKX2-1 expression in thyroid tumor cells and vice versa, thus establishing a positive feedback loop between both proteins. We also found a positive correlation between NKX2-1 and DICER1 expression in human thyroid tumors. DICER1 silencing decreased PAX8 expression and, importantly, the expression and activity of the sodium iodide symporter, which is essential for the diagnostic and therapeutic use of radioiodine in thyroid cancer. Conclusions: The differentiation transcription factors NKX2.1, PAX8, and CREB act in a positive feedback loop with DICER1. As the expression of these transcription factors is markedly diminished in thyroid cancer, our findings suggest that DICER1 downregulation in this cancer is mediated, at least partly, through impairment of its transcription.

MicroRNA Therapeutics in Cancer: Current Advances and Challenges

Simple Summary

Cancer is a complex disease associated with deregulation of numerous genes. In addition, redundant cellular pathways limit efficiency of monotarget drugs in cancer therapy. MicroRNAs are a class of gene expression regulators, which often function by targeting multiple genes. This feature makes them a double-edged sword (a) as attractive targets for anti-tumor therapy and concomitantly (b) as risky targets due to their potential side effects on healthy tissues. As for conventional antitumor drugs, nanocarriers have been developed to circumvent the problems associated with miRNA delivery to tumors. In this review, we highlight studies that have established the pre-clinical proof-of concept of miRNAs as relevant therapeutic targets in oncology. Particular attention was brought to new strategies based on nanovectorization of miRNAs as well as to the perspectives for their applications.

Abstract

The discovery of microRNAs (miRNAs) in 1993 has challenged the dogma of gene expression regulation. MiRNAs affect most of cellular processes from metabolism, through cell proliferation and differentiation, to cell death. In cancer, deregulated miRNA expression leads to tumor development and progression by promoting acquisition of cancer hallmark traits. The multi-target action of miRNAs, which enable regulation of entire signaling networks, makes them attractive tools for the development of anti-cancer therapies. Hence, supplementing downregulated miRNA by synthetic oligonucleotides or silencing overexpressed miRNAs through artificial antagonists became a common strategy in cancer research. However, the ultimate success of miRNA therapeutics will depend on solving pharmacokinetic and targeted delivery issues. The development of a number of nanocarrier-based platforms holds significant promises to enhance the cell specific controlled delivery and safety profile of miRNA-based therapies. In this review, we provide among the most comprehensive assessments to date of promising nanomedicine platforms that have been tested preclinically, pertaining to the treatment of selected solid tumors including lung, liver, breast, and glioblastoma tumors as well as endocrine malignancies. The future challenges and potential applications in clinical oncology are discussed.

Essential Role of the 14q32 Encoded miRNAs in Endocrine Tumors

BACKGROUND

The 14q32 cluster is among the largest polycistronic miRNA clusters. miRNAs encoded here have been implicated in tumorigenesis of multiple organs including endocrine glands.

METHODS

Critical review of miRNA studies performed in endocrine tumors have been performed. The potential relevance of 14q32 miRNAs through investigating their targets, and integrating the knowledge provided by literature data and bioinformatics predictions have been indicated.

RESULTS

Pituitary adenoma, papillary thyroid cancer and a particular subset of pheochromocytoma and adrenocortical cancer are characterized by the downregulation of miRNAs encoded by the 14q32 cluster. Pancreas neuroendocrine tumors, most of the adrenocortical cancer and medullary thyroid cancer are particularly distinct, as 14q32 miRNAs were overexpressed. In pheochromocytoma and growth-hormone producing pituitary adenoma, however, both increased and decreased expression of 14q32 miRNAs cluster members were observed. In the background of this phenomenon methodological, technical and biological factors are hypothesized and discussed. The functions of 14q32 miRNAs were also revealed by bioinformatics and literature data mining.

CONCLUSIONS

14q32 miRNAs have a significant role in the tumorigenesis of endocrine organs. Regarding their stable expression in the circulation of healthy individuals, further investigation of 14q32 miRNAs could provide a potential for use as biomarkers (diagnostic or prognostic) in endocrine neoplasms.

Molecular mechanisms of radioactive iodine refractoriness in differentiated thyroid cancer: Impaired sodium iodide symporter (NIS) expression owing to altered signaling pathway activity and intracellular localization of NIS

The advanced, metastatic differentiated thyroid cancers (DTCs) have a poor prognosis mainly owing to radioactive iodine (RAI) refractoriness caused by decreased expression of sodium iodide symporter (NIS), diminished targeting of NIS to the cell membrane, or both, thereby decreasing the efficacy of RAI therapy. Genetic aberrations (such as BRAF, RAS, and RET/PTC rearrangements) have been reported to be prominently responsible for the onset, progression, and dedifferentiation of DTCs, mainly through the activation of mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K)/AKT signaling pathways. Eventually, these alterations result in a lack of NIS and disabling of RAI uptake, leading to the development of resistance to RAI therapy. Over the past decade, promising approaches with various targets have been reported to restore NIS expression and RAI uptake in preclinical studies. In this review, we summarized comprehensive molecular mechanisms underlying the dedifferentiation in RAI-refractory DTCs and reviews strategies for restoring RAI avidity by tackling the mechanisms.

MiR-146b-3p protects against AR42J cell injury in cerulein-induced acute pancreatitis model through targeting Anxa2

Background

Acute pancreatitis (AP) is a common inflammatory disorder. MicroRNAs play crucial roles in the pathogenesis of AP. In this article, we explored the detailed role and molecular mechanisms of miR-146b-3p in AP progression.

Methods

The rat AR42J cells were treated with cerulein to establish the AP model in vitro. The miR-146b-3p and Annexin A2 (Anxa2) mRNA levels were assessed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Cell viability and apoptosis were tested using the Cell Counting Kit-8 (CCK-8) and flow cytometry assays, respectively. Caspase-3 activity and the production of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α (TNF-α) were measured by enzyme-linked immunosorbent assay and qRT-PCR. Targeted interaction between miR-146b-3p and Anxa2 was verified by the dual-luciferase reporter and RNA immunoprecipitation assays. Western blot analysis was performed to detect the expression of Anxa2 protein.

Results

Our data revealed that miR-146b-3p was significantly downregulated in AP samples. The enforced expression of miR-146b-3p alleviated cerulein-induced injury in AR42J cells, as evidenced by the promotion in cell viability and the repression in cell apoptosis, as well as the reduction in IL-1β, IL-6, and TNF-α production. Anxa2 was directly targeted and inhibited by miR-146b-3p. Moreover, the alleviative effect of miR-146b-3p overexpression on cerulein-induced AR42J cell injury was mediated by Anxa2.

Conclusions

The current work had led to the identification of miR-146b-3p overexpression that protected against cerulein-induced injury in AR42J cells at least in part by targeting Anxa2, revealing a promising target for AP diagnosis and treatment.

Development of Flow Cytometric Assay for Detecting Papillary Thyroid Carcinoma Related hsa-miR-146b-5p through Toehold-Mediated Strand Displacement Reaction on Magnetic Beads

In this work, a simple enzyme-free flow cytometric assay (termed as TSDR-based flow cytometric assay) has been developed for the detection of papillary thyroid carcinoma (PTC)-related microRNA (miRNA), hsa-miR-146b-5p with high performance through the toehold-mediated strand displacement reaction (TSDR) on magnetic beads (MBs). The complementary single-stranded DNA (ssDNA) probe of hsa-miR-146b-5p was first immobilized on the surface of MB, which can partly hybridize with the carboxy-fluorescein (FAM)-modified ssDNA, resulting in strong fluorescence emission. In the presence of hsa-miR-146b-5p, the TSDR is trigged, and the FAM-modified ssDNA is released form the MB surface due to the formation of DNA/RNA heteroduplexes on the MB surface. The fluorescence emission change of MBs can be easily read by flow cytometry and is strongly dependent on the concentration of hsa-miR-146b-5p. Under optimal conditions, the TSDR-based flow cytometric assay exhibits good specificity, a wide linear range from 5 to 5000 pM and a relatively low detection limit (LOD, 3σ) of 4.21 pM. Moreover, the practicability of the assay was demonstrated by the analysis of hsa-miR-146b-5p amounts in different PTC cells and clinical PTC tissues.

Progression Risk Assessment of Post-surgical Papillary Thyroid Carcinoma Based on Circular RNA-Associated Competing Endogenous RNA Mechanisms

Background: Accurate risk assessment of post-surgical progression in papillary thyroid carcinoma (PTC) patients is critical. Exploring key differentially expressed mRNAs (DE-mRNAs) regulated by differentially expressed circular RNAs (circRNAs) via the ceRNA mechanism could help establish a novel assessment tool. Methods: ceRNA network was established based on differentially expressed RNAs and correlation analysis. DE-mRNAs within the ceRNA network associated with progression-free interval (PFI) of PTC were identified to construct a prognostic ceRNA regulatory subnetwork. least absolute shrinkage and selection operator (LASSO)-Cox regression was applied to identify hub DE-mRNAs and establish a novel DE-mRNA signature in predicting PFI of PTC. Results: Six hub DE-mRNAs, namely, CLCNKB, FXBO27, FXYD6, RIMS2, SPC24, and CDKN2A, were identified to be most significantly related to the PFI of PTC, and a prognostic DE-mRNA signature was proposed. A nomogram incorporating the DE-mRNA signature and clinical parameters was established to improve the progression risk assessment in post-surgical PTC, which was superior to the American Thyroid Association risk stratification system and distant Metastasis, patient Age, Completeness of resection, local Invasion, and tumor Size (MACIS) score American Joint Committee on Cancer staging system. Conclusions: Based on the circRNA-associated ceRNA RNA mechanism, a DE-mRNA signature and prognostic nomogram was established, which may improve the progression risk assessment in post-surgical PTC.

Downregulation of miR-146b-3p Inhibits Proliferation and Migration and Modulates the Expression and Location of Sodium/Iodide Symporter in Dedifferentiated Thyroid Cancer by Potentially Targeting MUC20

The dedifferentiation of differentiated thyroid cancer (DTC) is a challenging problem for radioactive iodine (¹³¹I) treatment, also known as radioiodine refractory differentiated thyroid cancer (RAIR-DTC). The purpose of this study was to further explore the mechanism of the redifferentiation of dedifferentiated thyroid cancer. Ineffective and effective groups of ¹³¹I therapy were analyzed and compared in both our clinical and TCGA samples. Whole-exome sequencing, mutation analysis, transcriptome analysis, and in vitro functional experiments were conducted. FLG, FRG1, MUC6, MUC20, and PRUNE2 were overlapping mutation genes between our clinical cases, and the TCGA cases only appeared in the ineffective group. The expression of miR-146b-3p target MUC20 was explored. The expression levels of miR-146b-3p and MUC20 were significantly increased, and the inhibition of miR-146b-3p expression significantly inhibited proliferation and migration, promoted apoptosis, regulated the expression and location of thyroid differentiation-related genes, and sodium/iodide symporter (NIS) in dedifferentiated thyroid cancer cells (WRO). Thus, miR-146b-3p potentially targets MUC20 participation in the formation of DTC dedifferentiation, resulting in resistance to ¹³¹I and the loss of the iodine uptake ability of DTC cancer foci, promoting refractory differentiated thyroid cancer. miR-146b-3p may be a potentially therapeutic target for the reapplication of ¹³¹I therapy in dedifferentiated thyroid cancer patients.

Non-Coding RNAs: Uncharted Mediators of Thyroid Cancer Pathogenesis

Thyroid cancer is the most prevalent malignancy of the endocrine system and the ninth most common cancer globally. Despite the advances in the management of thyroid cancer, there are critical issues with the diagnosis and treatment of thyroid cancer that result in the poor overall survival of undifferentiated and metastatic thyroid cancer patients. Recent studies have revealed the role of different non-coding RNAs (ncRNAs), such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) that are dysregulated during thyroid cancer development or the acquisition of resistance to therapeutics, and may play key roles in treatment failure and poor prognosis of the thyroid cancer patients. Here, we systematically review the emerging roles and molecular mechanisms of ncRNAs that regulate thyroid tumorigenesis and drug response. We then propose the potential clinical implications of ncRNAs as novel diagnostic and prognostic biomarkers for thyroid cancer.

Thyroid hormone, gene expression, and Central Nervous System: Where we are

Thyroid hormones (TH; T3 and T4) play a fundamental role in the fetal stage to the adult phase, controlling gene and protein expression in virtually all tissues. The endocrine and CNS systems have relevant interaction, and the TH are pivotal for the proper functioning of the CNS. A slight failure to regulate TH availability during pregnancy and/or childhood can lead to neurological disorders, for example, autism and cognitive impairment, or depression. In this review, we highlight how TH acts in controlling gene expression, its role in the CNS, and what substances widely found in the environment can cause in this tissue. We highlight the role of Endocrine Disruptors used on an everyday basis in the processing of mRNAs responsible for neurodevelopment. We conclude that TH, more precisely T3, acts mainly throughout its nuclear receptors, that the deficiency of this hormone, either due to the lack of its main substrate iodine, or by to incorrect organification of T4 and T3 in the gland, or by a mutation in transporters, receptors and deiodinases may cause mild (dysregulated mood in adulthood) to severe neurological impairment (Allan-Herndon-Dudley syndrome, presented as early as childhood); T3 is responsible for the expression of numerous CNS genes related to oxygen transport, growth factors, myelination, cell maturation. Substances present in the environment and widely used can interfere with the functioning of the thyroid gland, the action of TH, and the functioning of the CNS.

Novel therapeutic options for radioiodine-refractory thyroid cancer: redifferentiation and beyond

PURPOSE OF REVIEW

Radioiodine-refractory thyroid cancers represent the main cause of thyroid cancer-related death. At present, targeted therapies with multikinase inhibitors represent a unique therapeutic tool, though they have limited benefit on patient survival and severe drug-associated adverse events. This review summarizes current treatment strategies for radioiodine-refractory thyroid cancer and focuses on novel approaches to redifferentiate thyroid cancer cells to restore responsiveness to radioiodine administration.

RECENT FINDINGS

We summarize and discuss recent clinical trial findings and early data from real-life experiences with multikinase-inhibiting drugs. Possible alternative strategies to traditional redifferentiation are also discussed.

SUMMARY

The current review focuses primarily on the major advancements in the knowledge of the pathophysiology of iodine transport and metabolism and the genetic and epigenetic alterations occurring in thyroid neoplasia as described using preclinical models. Results of clinical studies employing new compounds to induce thyroid cancer cell redifferentiation by acting against specific molecular targets are also discussed. Finally, we describe the current scenario emerging from such findings as well as future perspectives.

The Prognostic Value of MicroRNAs in Thyroid Cancers-A Systematic Review and Meta-Analysis

Thyroid cancer (TC) includes various phenotypes, from indolent to highly aggressive cancer. The limitations of the current prognostication systems to predict the recurrence risk and the variability in expression of the genes involved in the thyroid carcinogenesis uncover the need for new prognostic biomarkers by taking into account potential epigenetic differences. We aimed to summarize the current knowledge regarding the prognostic impact of microRNAs (miRNAs) in TC. A literature search was conducted in PubMed, Embase, Scopus, and Web of Science databases. Both upregulated and downregulated miRNAs are significantly correlated with worse overall survival (hazard ratio (HR) = 5.94, 95% CI: 2.73-12.90, p < 0.001; HR = 0.51, 95% CI: 0.26-0.96, p = 0.048) disease/recurrence-free survival (HR = 1.58, 95% CI: 1.08-2.32, p = 0.003; HR = 0.37, 95%, CI: 0.24-0.60, p < 0.001). Sensitivity analysis revealed a significant association between the higher expression of miR-146b, miR-221, and miR-222 and the recurrence of papillary TC (OR = 9.11, 95% CI 3.00 to 27.52; p < 0.001; OR = 3.88, 95% CI 1.34 to 11.19, p < 0.001; OR = 6.56, 95% CI 2.75 to 15.64, p < 0.001). This research identified that miR-146b, miR-221, and miR-222 could serve as potential prognostic biomarkers in TC, particularly in PTC. Further studies are needed to strengthen these findings and sustain its clinical applicability.

A miRNA-clinicopathological nomogram for the prediction of central lymph node metastasis in papillary thyroid carcinoma-analysis from TCGA database

It is of significance to evaluate central lymph node status in patients with papillary thyroid carcinoma (PTC), because it can decrease postoperative complications resulting from unnecessary prophylactic central lymph node dissection (CLND). Due to the low sensitivity and specificity of neck ultrasonography in the evaluation of central lymph node metastasis (CLNM), it is urgently required to find alternative biomarkers to predict CLNM in PTC patients, which is the main purpose of this study.RNA-sequencing datasets and clinical data of 506 patients with thyroid carcinoma from the Cancer Genome Atlas (TCGA) database were downloaded and analyzed to identify differentially expressed miRNAs (DEMs), which can independently predict CLNM in PTC. A nomogram predictive of CLNM was developed based on clinical characteristics and the identified miRNAs. Receiver operating characteristics curves were drawn to evaluate the predictive performance of the nomogram. Bioinformatics analyses, including target genes identification, functional enrichment analysis, and protein-protein interaction network, were performed to explore the potential roles of the identified DEMs related to CLNM in PTC.A total of 316 PTC patients were included to identify DEMs. Two hundred thirty-seven (75%) PTC patients were randomly selected from the 316 patients as a training set, while the remaining 79 (25%) patients were regarded as a testing set for validation. Two DEMs, miRNA-146b-3p (HR: 1.327, 95% CI = 1.135-1.551, P = .000) and miRNA-363-3p (HR: 0.714, 95% CI = 0.528-0.966, P = .029), were significantly associated with CLNM. A risk score based on these 2 DEMs and calculating from multivariate logistic regression analysis, was significantly lower in N0 group over N1a group in both training (N0 vs N1a: 2.04 ± 1.01 vs 2.73 ± 0.61, P = .000) and testing (N0 vs N1a: 2.20 ± 0.93 vs 2.79 ± 0.68, P = .003) sets. The nomogram including risk score, age, and extrathyroidal extension (ETE) was constructed in the training set and was then validated in the testing set, which showed better prediction value than the other three predictors (risk score, age, and ETE) in terms of CLNM identification. Bioinformatics analyses revealed that 5 hub genes, SLC6A1, SYT1, COL19A1, RIMS2, and COL1A2, might involve in pathways including extracellular matrix organization, ion transmembrane transporter activity, axon guidance, and ABC transporters.On the basis of this study, the nomogram including risk score, age, and ETE showed good prediction of CLNM in PTC, which has a potential to facilitate individualized decision for surgical plans.

Molecular Markers Guiding Thyroid Cancer Management

The incidence of thyroid cancer is rapidly increasing, mostly due to the overdiagnosis and overtreatment of differentiated thyroid cancer (TC). The increasing use of potent preclinical models, high throughput molecular technologies, and gene expression microarrays have provided a deeper understanding of molecular characteristics in cancer. Hence, molecular markers have become a potent tool also in TC management to distinguish benign from malignant lesions, predict aggressive biology, prognosis, recurrence, as well as for identification of novel therapeutic targets. In differentiated TC, molecular markers are mainly used as an adjunct to guide management of indeterminate nodules on fine needle aspiration biopsies. In contrast, in advanced thyroid cancer, molecular markers enable targeted treatments of affected signalling pathways. Identification of the driver mutation of targetable kinases in advanced TC can select treatment with mutation targeted tyrosine kinase inhibitors (TKI) to slow growth and reverse adverse effects of the mutations, when traditional treatments fail. This review will outline the molecular landscape and discuss the impact of molecular markers on diagnosis, surveillance and treatment of differentiated, poorly differentiated and anaplastic follicular TC.

Inhibition of microRNA-875-5p promotes radioiodine uptake in poorly differentiated thyroid carcinoma cells by upregulating sodium-iodide symporter

BACKGROUND AND AIM

Poorly differentiated thyroid carcinoma (PDTC) is an endocrine malignancy that is challenging to treat due to its limited radioiodine uptake. microRNAs (miRNAs or miRs) have been shown to be useful in treating many types of tumors, including PDTC. This study aims to evaluate the potential effect of miR-875-5p on the radioiodine uptake of PDTC and to clarify the underlying mechanisms.

METHODS

Expression of miR-875-5p and sodium-iodide symporter (NIS) in tissues and cell lines was determined using RT-qPCR. The binding relationship between miR-875-5p and NIS was predicted through in silico analysis and verified by dual-luciferase reporter gene assay. A series of miR-875-5p mimic, miR-875-5p inhibitor, shRNA against NIS, and overexpressed NIS plasmids were introduced into PDTC cells. We then evaluated the cell viability, colony formation, apoptosis, and radioiodine uptake of each PDTC sample via CCK-8 assay, clonogenic assay, flow cytometry, and γ counter, respectively.

RESULTS

miR-875-5p was found to be highly expressed, but NIS was poorly expressed in DTC tissues and PDTC cell lines. NIS was verified to be a target gene of miR-875-5p. Upregulation of miR-875-5p was found to induce PDTC cell proliferation, and reduce apoptosis and radioiodine uptake in vitro through down-regulation of NIS. In an in vivo orthotopic model, the enhancement of miR-875-5p led to the reduction of NIS expression and radioiodine uptake in the thyroid tumors.

CONCLUSIONS

Altogether, the findings of the current study suggest that down-regulated miR-875-5p expression could promote its target gene NIS to increase radioiodine uptake in PDTC, constituting a preventive strategy against PDTC.

Nevirapine Increases Sodium/Iodide Symporter-Mediated Radioiodide Uptake by Activation of TSHR/cAMP/CREB/PAX8 Signaling Pathway in Dedifferentiated Thyroid Cancer

Nevirapine has been proved to be effective in inducing re-differentiation and suppressing tumor growth in several tumor cells. This study aims to investigate the therapeutic potential of nevirapine in dedifferentiated thyroid cancer (DeTC), which refractory to radioiodine treatment and the underlying mechanisms. The results indicated that nevirapine significantly inhibited the proliferation and increased the expressions of thyroid differentiation-related genes, thyroid stimulating hormone receptor (TSHR), sodium/iodide symporter (NIS), thyroid peroxidase (TPO), and transcriptional factor paired box 8 (PAX8) in dedifferentiated thyroid cancer cells (WRO 82-1 and dFTC-133). Furthermore, nevirapine also enhanced radioiodide uptake significantly both in vitro and in vivo, and inhibited the growth of xenograft tumors. Nevirapine might improve radioiodine sensitivity via the activation of TSHR/cAMP/CREB/PAX8 signaling pathway. This study demonstrates that nevirapine could be potentially used to improve radioiodine therapeutic efficacy in dedifferentiated thyroid cancer patients.

ADAR1-mediated RNA editing is a novel oncogenic process in thyroid cancer and regulates miR-200 activity

Adenosine deaminases acting on RNA (ADARs) convert adenosine to inosine in double-stranded RNA. A-to-I editing of RNA is a widespread posttranscriptional process that has recently emerged as an important mechanism in cancer biology. A-to-I editing levels are high in several human cancers, including thyroid cancer, but ADAR1 editase-dependent mechanisms governing thyroid cancer progression are unexplored. To address the importance of RNA A-to-I editing in thyroid cancer, we examined the role of ADAR1. Loss-of-function analysis showed that ADAR1 suppression profoundly repressed proliferation, invasion, and migration in thyroid tumor cell models. These observations were validated in an in vivo xenograft model, which showed that ADAR1-silenced cells had a diminished ability to form tumors. RNA editing of miRNAs has the potential to markedly alter target recognition. According to TCGA data, the tumor suppressor miR-200b is overedited in thyroid tumors, and its levels of editing correlate with a worse progression-free survival and disease stage. We confirmed miR-200b overediting in thyroid tumors and we showed that edited miR-200b has weakened activity against its target gene ZEB1 in thyroid cancer cells, likely explaining the reduced aggressiveness of ADAR1-silenced cells. We also found that RAS, but not BRAF, modulates ADAR1 levels, an effect mediated predominantly by PI3K and in part by MAPK. Lastly, pharmacological inhibition of ADAR1 activity with the editing inhibitor 8-azaadenosine reduced cancer cell aggressiveness. Overall, our data implicate ADAR1-mediated A-to-I editing as an important pathway in thyroid cancer progression, and highlight RNA editing as a potential therapeutic target in thyroid cancer.

Role of diets and exercise in ameliorating obesity-related hepatic steatosis: Insights at the microRNA-dependent thyroid hormone synthesis and action

AIMS

The present study was designed to compare the effects of a low-fat diet (LF), calorie restriction (CR), quercetin (Que) and exercise (Ex) on hepatic steatosis in a high-fat (HF) diet-induced obesity prone (OP) model in the perspective of microRNA (miR)-dependent thyroid hormone (TH) synthesis and action.

MAIN METHODS

Male C57BL/6J mice were administered a HF diet for 10 weeks to induce OP phenotype and then divided into 5 groups, HF diet (OP-HF), LF diet (OP-LF), 70% CR (OP-CR), 0.05% Que (OP-Que) and a treadmill exercise regimen (OP-Ex); one additional group fed LF diet served as control (LF). 7 weeks later, serum indexes, metabolic alterations, redox status and histological appearance in the thyroid and liver, and TH related miRs with their targets expressions were determined.

KEY FINDINGS

No significance on T3 levels was observed among the six groups. LF, CR, Que and Ex significantly ameliorated HF-induced hepatic steatosis to varying degrees, inhibited T4 production via differentially elevating miR-339, miR-383 and miR-146b to decrease NIS expression and regulating miR-200a/Nrf2 to maintain redox status in the thyroid. Furthermore, these four interventions differentially and significantly decreased miR-383 and miR-146b to elevate TRb and DIO1 expression, and subsequent TH responsive lipid metabolism genes regulation. Among them, the effects of CR on hepatic steatosis were the most prominent.

SIGNIFICANCE

Our data indicated that amelioration of hepatic steatosis by LF, CR, Que and Ex resulted in many shared, but also many differential changes in the miR-dependent TH production and action.

Thyroid Follicular Cell Loss of Differentiation Induced by MicroRNA miR-17-92 Cluster Is Attenuated by CRISPR/Cas9n Gene Silencing in Anaplastic Thyroid Cancer

Background: Loss of the expression of thyroid differentiation markers such as sodium iodide symporter (NIS) and, consequently, radioiodine refractoriness is observed in aggressive papillary thyroid cancer and anaplastic thyroid cancer (ATC) that may harbor the BRAF^V600E mutation. Activation of the BRAF^V600E oncogene in thyroid follicular cells induces the expression of the miR-17-92 cluster that comprises seven mature microRNAs (miRNAs). miRNAs are a class of endogenous small RNAs (∼22 nt) that regulate gene expression post-transcriptionally. Indeed, miR-17-92 is overexpressed in ATC, and in silico prediction shows the potential targeting of thyroid transcription factors and tumor suppressor pathways. In this study, we aimed to investigate the role of the miR-17-92 cluster in thyroid cell differentiation and function. Methods:miR-17-92 silencing was performed using CRISPR/Cas9n-guided genomic editing of the miR-17-92 gene in the KTC2 ATC cell line, and miR-17-92 cluster or individual miRNAs were overexpressed in PCCl3 thyroid cells to evaluate the influence in thyroid cell differentiation and cell function. Results: In this study, we demonstrate that CRISPR/Cas9n gene editing of the miR-17-92 cluster results in promotion of thyroid follicular cell differentiation (NIS, thyroperoxidase, thyroglobulin, PAX8, and NKX2-1 expression) in the KTC2 ATC cell line and inhibits cell migration and proliferation by restoring transforming growth factor beta (TGF-β) signaling pathway responsiveness. Moreover, induction of the miR-17-92 cluster in normal thyroid follicular cells strongly impairs thyroid differentiation and induces a pro-oncogenic effect by blocking TGF-β signaling and increasing cell migration. Conclusions:miR-17-92 is a potent regulator of thyroid follicular cell differentiation, and CRISPR/Cas9n-mediated editing of the miR-17-92 gene efficiently blocks miR-17-92 expression in the KTC2 ATC cell line, resulting in improvement of thyroid differentiation. Thus, targeting miR-17-92 could provide a potential molecular approach to restoring thyroid cell differentiation and NIS expression in aggressive thyroid cancer.

PTEN-knockdown disrupts the morphology, growth pattern and function of Nthy-Ori 3-1 cells by downregulating PAX8 expression

The incidence of thyroid disorders, which are common endocrine diseases, has rapidly increased in recent years. However, the etiology and pathogenesis of these disorders remain unclear. Phosphatase and tension homolog (PTEN) is a dual-specific phosphatase that is associated with multiple thyroid disorders; however, the role of PTEN in thyroid disorders remains unknown. In the present study, the human thyroid follicular epithelial cell line Nthy-Ori 3-1 was used to determine the role of PTEN in thyroid disorders. PTEN expression was knocked down using a PTEN-specific short hairpin RNA. Western blotting was subsequently used to determine protein expression, the Matrigel tube formation assay and iodide uptake assay were applied for evaluating the morphology and function of thyroid cells. The results showed that PTEN knockdown decreased the protein expression of paired box 8 (PAX8). The morphology and tubular-like growth pattern of thyroid cells were therefore disrupted, and restoration of PAX8 expression reversed these effects. Furthermore, PTEN-knockdown decreased the expression of specific thyroid proteins (thyroglobulin, TG; thyroid peroxidase, TPO; and sodium/iodide symporter, NIS) and inhibited the iodide uptake ability of thyroid cells by downregulating PAX8, suggesting that PTEN deficiency may impair the function of thyroid cells. In conclusion, the present study reported an important function of PTEN in normal thyroid cells and identified the involvement of PAX8. These results may improve understanding of the role of PTEN in the pathogenesis of thyroid disorders.

Interplay of TGFβ signaling and microRNA in thyroid cell loss of differentiation and cancer progression

Thyroid cancer has been rapidly increasing in prevalence among humans in last 2 decades and is the most prevalent endocrine malignancy. Overall, thyroid-cancer patients have good rates of long-term survival, but a small percentage present poor outcome. Thyroid cancer aggressiveness is essentially related with thyroid follicular cell loss of differentiation and metastasis. The discovery of oncogenes that drive thyroid cancer (such as RET, RAS, and BRAF), and are aligned in the MAPK/ERK pathway has led to a new perspective of thyroid oncogenesis. The uncovering of additional oncogene-modulated signaling pathways revealed an intricate and active signaling cross-talk. Among these, microRNAs, which are a class of small, noncoding RNAs, expanded this cross-talk by modulating several components of the oncogenic network - thus establishing a new layer of regulation. In this context, TGFβ signaling plays an important role in cancer as a dual factor: it can exert an antimitogenic effect in normal thyroid follicular cells, and promote epithelial-to-mesenchymal transition, cell migration, and invasion in cancer cells. In this review, we explore how microRNAs influence the loss of thyroid differentiation and the increase in aggressiveness of thyroid cancers by regulating the dual function of TGFβ. This review provides directions for future research to encourage the development of new strategies and molecular approaches that can improve the treatment of aggressive thyroid cancer.

MicroRNA expression profile in Treg cells in the course of primary immune thrombocytopenia

Primary immune thrombocytopenia (ITP) is an autoimmune bleeding disorder which characterizes with platelet production impairment and platelet destruction increment. CD4⁺CD25⁺Foxp3⁺ Treg cells (Tregs) are involved in the immune pathogenesis of ITP. MicroRNAs (miRNAs) are also involved in ITP and their loss of function is shown to facilitate immune disorders. Thus, the miRNA expression profile in Tregs from ITP was analyzed in this study. We assessed the genome-wide miRNA expression profile of three newly diagnosed adult patients with ITP and three healthy controls using microarray analysis of CD4⁺CD25⁺CD127^dim/− Tregs that were sorted using an immune magnetic bead kit. The miRNA microarray chip was based on miRBase 18.0 and Volcano Plot filtering software used to analyze the miRNA profile in Tregs. Distinct miRNA expression was further validated by fluorescence-based real-time quantitative PCR (qPCR). We found that 502 human miRNAs were differentially expressed (244 upregulated and 258 downregulated) in patients with ITP compared with healthy donors. We identified 37 miRNAs expressed significantly, including 26 upregulated and 11 downregulated. Among the deregulated miRNAs, three downregulated miRNAs including miR-155–5p, miR-146b-5p, and miR-142–3p were selected for qPCR verification. We confirmed that miR-155–5p, miR-146b–5p, and miR-142–3p were significantly decreased in Tregs from patients with ITP compared with healthy controls. Compared with the healthy controls, miRNAs expressed differentially in the Tregs of patients with ITP. The levels of expression of miR-155–5p, miR-146b-5p, and miR-142–3p were significantly decreased. Therefore, the deregulation of miRNAs may affect the function of Tregs in the course of ITP.