A versatile nanoplatform carrying cascade Pt nanozymes remodeling tumor microenvironment for amplified sonodynamic/chemo therapy of thyroid cancer.

Thyroid cancer is increasing globally, with anaplastic thyroid carcinoma (ATC) being the most aggressive type and having a poor prognosis. Current clinical treatments for thyroid cancer present numerous challenges, including invasiveness and the necessity of lifelong medication. Furthermore, a significant portion of patients with ATC experience cancer recurrence and metastasis. To overcome this dilemma, we developed a pH-responsive biomimetic nanocarrier (CLP@HP-A) through the incorporation of Chlorin e6 (Ce6) and Lenvatinib (Len) within hollow polydopamine nanoparticles (HP) that were further modified with platinum nanoparticles (Pt), enabling synergistic chemotherapy and sonodynamic therapy. The CLP@HP-A nanocarriers exhibited specific binding with galectin-3 receptors, facilitating their internalization through receptor-mediated endocytosis for targeted drug delivery. Upon exposure to ultrasound (US) irradiation, Ce6 rapidly generated reactive oxygen species (ROS) to induce significant oxidative stress and trigger apoptosis in tumor cells. Additionally, Pt not only alleviated tumor hypoxia by catalyzing the conversion of H2O2 to oxygen (O2) but also augmented intracellular ROS levels through the production of hydroxyl radicals (•OH), thereby enhancing the efficacy of sonodynamic therapy. Moreover, Len demonstrated a potent cytotoxic effect on thyroid cancer cells through the induction of apoptosis. Transcriptomics analysis findings additionally corroborated that CLP@HP-A effectively triggered cancer cell apoptosis, thereby serving as a crucial mechanism for its cytotoxic effects. In conclusion, the integration of sonodynamic/chemo combination therapy with targeted drug delivery systems offers a novel approach to the management of malignant tumors.

New insights into the mechanisms of the extracellular matrix and its therapeutic potential in anaplastic thyroid carcinoma.

Anaplastic thyroid carcinoma (ATC) is the most aggressive thyroid cancer, and it has a poor prognosis and high probability of metastatic recurrence. The long-term survival of cancer cells depends on their ability to settle in a favorable environment. Cancer cells interact with other cells in the tumor microenvironment to shape the "soil" and make it suitable for cell growth by forming an extremely complex tumor ecosystem. The extracellular matrix (ECM) is an essential component of the tumor ecosystem, and its biological and mechanical changes strongly affect tumor invasion, metastasis, immune escape and drug resistance. Compared to normal tissues, biological processes, such as collagen synthesis and ECM signaling, are significantly activated in ATC tissues. However, how ATC triggers changes in the properties of the ECM and its interaction with the ECM remain poorly characterized. Therefore, an in-depth study of the regulatory mechanism of the abnormal activation of ECM signaling in ATC is highly important for achieving the therapeutic goal of exerting antitumor effects by destroying the "soil" in which cancer cells depend for survival. In this research, we revealed the aberrant activation state of ECM signaling in ATC progression and attempted to uncover the potential mechanism of action of ECM components in ATC, with the aim of providing new drug targets for ATC therapy.

Exploring the transcriptional cooperation between RUNX2 and its associated elncRNA RAIN.

Recent insights into the mechanisms controlling gene expression identified enhancer-associated long non-coding RNAs (elncRNAs) as master players of transcription in cancers. RUNX2, a mammalian RUNT-related transcription factor, is increasingly recognized in cancer biology for its role in supporting survival and progression also in thyroid cancer (TC). We recently identified, within the RUNX2 locus, a novel elncRNA that we named RAIN (RUNX2 associated intergenic lncRNA). We showed that RAIN and RUNX2 expression correlate in TC, both in vitro and in vivo, and that RAIN promotes RUNX2 expression by interacting with and affecting the activity of the RUNX2 P2 promoter through two distinct mechanisms. Here, we took forward these observations to explore the genome-wide transcriptional function of RAIN and its contribution to the RUNX2-dependent gene expression program in TC. By combining multiple omics data, we demonstrated that RAIN functionally cooperates with RUNX2 to the regulation of a subset of functionally related genes involved in promoting matrix remodeling, migration, and loss of differentiation. We showed that RAIN interacts with RUNX2 and its expression is required for the efficient recruitment of this TF to its target regulatory regions. In addition, our data revealed that besides RUNX2, RAIN governs a hierarchically organized complex transcriptional program by controlling a core of cancer-associated TFs that, in turn, orchestrate the expression of downstream genes. This evidence indicates that the functional cooperation observed between RAIN and RUNX2 can be a diffuse work mechanism for this elncRNA.

Molecular mechanisms and clinicopathological characteristics of inhibin ßA in thyroid cancer metastasis.

The present study aimed to investigate the role and mechanism of inhibin ßA (INHBA) in thyroid cancer (TC), and to determine its potential impact on the aggressive behavior of TC cells. The present study employed a comprehensive approach, using public databases, such as the Gene Expression Omnibus and The Cancer Genome Atlas, to identify and analyze the expression of INHBA in TC. Cell transfection, reverse transcription­quantitative PCR, western blot analysis, immunohistochemistry and in vivo assays were conducted to investigate the functional effects of INHBA on TC. In addition, the present study explored the molecular mechanisms underlying the effects of INHBA, focusing on the potential impact on the RhoA signaling pathway and associated molecular cascades. Bioinformatics analysis revealed a significant association between INHBA expression and TC, and INHBA expression was markedly upregulated in TC tissues compared with in healthy control tissues. The results of functional studies demonstrated that INHBA overexpression increased the migration and invasion of TC cells, and the opposite result was observed following INHBA knockdown. Mechanistic investigations indicated that INHBA modulated the RhoA pathway, leading to alterations in the phosphorylation status of LIM kinase 1 (LIMK) and cofilin, key regulators of cytoskeletal dynamics and cell motility. Following the introduction of transfected TC cells into zebrafish and nude mouse models, the results of the present study demonstrated that INHBA knockdown attenuated the metastatic potential of TC cells. In conclusion, INHBA may serve a pivotal role in promoting the aggressive phenotype of TC cells through modulating the RhoA/LIMK/cofilin signaling axis. These findings highlight INHBA as a potential biomarker and therapeutic target for the management of aggressive TC.

FBXO2 promotes the progression of papillary thyroid carcinoma through the p53 pathway.

Emerging evidence have demonstrated that F-box only protein 2 (FBXO2) is intimately associated with malignant tumor development and occurrence. However, neither the functions nor the molecular mechanisms underlying FBXO2 have been determined in the papillary thyroid carcinoma (PTC). The quantitative real-time PCR (qRT-PCR), western blotting and immunohistochemistry were carried out to detect the FBXO2 expression in PTC tissues. CCK-8 assay, EdU assay and flow cytometry were used to assess cell proliferation, cell cycle and apoptosis. The trans-well assay was conducted to determine the cell invasiveness. The effect of FBXO2 on PTC cell proliferation in vivo was observed through a subcutaneous tumor formation experiment in nude mice. Immunoprecipitation were conducted to detect the interaction between FBXO2 and p53. The ubiquitination assays were conducted to assess the regulation of p53 ubiquitination by FBXO2. FBXO2 was overexpressed in both PTC tissues and cell lines. FBXO2 expression positively correlated with PTC tumor size, lymphatic metastasis, and extramembranous invasion. Furthermore, silencing FBXO2 inhibited PTC cell proliferation and promoted apoptosis. The overexpression of FBXO2 significantly promotes PTC cell proliferation. Mechanistic studies revealed that FBXO2 could directly bind to p53 and promote its ubiquitination degradation. Knockdown of p53 partially reversed the progression arrest induced by FBXO2 Knockdown in PTC cells. FBXO2 knockdown inhibited PTC cell proliferation and promoted apoptosis by targeting p53 for ubiquitination and degradation. This process represents a research foundation for its diagnostic and therapeutic applications.

Uncovering the connection between obesity and thyroid cancer: the therapeutic potential of adiponectin receptor agonist in the AdipoR2-ULK axis.

Adiponectin, a unique adipose-derived factor, is significantly downregulated in obesity, making it a crucial target for tumor-related metabolic research. AdipoRon is a novel adiponectin receptor agonist with the advantages of a small molecular weight, high stability and a long half-life. By screening the cervical adipose tissue of papillary thyroid carcinoma (PTC) patients with adipokine antibody array, we found that adiponectin was a potential correlation factor between obesity and PTC progression. AdipoRon has oral activity and is easily absorbed and delivered to target tissues. The effects of AdipoRon on thyroid cancer have not been reported. In this study, we identified adiponectin receptor 1 (AdipoR1) and AdipoR2 on the surface of thyroid cancer cell lines. AdipoRon inhibited the proliferation and migration of thyroid cancer cells, limited energy metabolism in thyroid cancer cells, promoted differentiation of thyroid cancer cells, and induced autophagy and apoptosis. Mechanistic studies revealed that AdipoRon inhibited p-mTOR Ser2448 and p-p70S6K Thr389, and activated ULK1 and p-ULK1. ULK1 knockdown suppressed the effect of AdipoRon on LC3BII/I protein and lysosomes. AdipoR2 knockdown reduced AdipoRon-induced autophagy in thyroid cancer cells. This study is the first to demonstrate the role of AdipoRon in PTC. Our findings illustrate a previously unknown function and mechanism of the AdipoRon-AdipoR2-ULK/p-ULK1 axis in PTC and lay the foundation for clinical translation of AdipoRon to PTC. Targeting the AdipoRon-AdipoR2-ULK/p-ULK1 axis may represent a new therapeutic strategy for PTC.

Potential functions and mechanisms of lysine crotonylation modification (Kcr) in tumorigenesis and lymphatic metastasis of papillary thyroid cancer (PTC).

OBJECTIVES: To examine the putative functions and mechanisms of lysine crotonylation (Kcr) during the development and progression of papillary thyroid cancer (PTC). METHODS: Samples of thyroid cancer tissues were collected and subjected to liquid chromatography-tandem mass spectrometry. Crotonylated differentially expressed proteins (DEPs) and differentially expressed Kcr sites (DEKSs) were analyzed by Motif, dynamic expression model analysis (Mfuzz), subcellular localization, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway annotation, Go Ontology (GO) annotation, and protein-protein interaction analysis (PPI). Validation was performed by immunohistochemistry (IHC). RESULTS: A total of 262 crotonylated DEPs and 702 DEKSs were quantitated. First, for the tumor/normal comparison, a dynamic expression model analysis (Mfuzz) of the DEKSs revealed that clusters 1, 3, and 4 increased with the progression of thyroid cancer; however, cluster 6 showed a dramatic increase during the transition from N0-tumor to N1-tumor. Furthermore, based on GO annotation, KEGG, and PPI, the crotonylated DEPs were primarily enriched in the PI3K-Akt signaling pathway, Cell cycle, and Hippo signaling pathway. Of note, crosstalk between the proteome and Kcr proteome suggested a differential changing trend, which was enriched in Thyroid hormone synthesis, Pyruvate metabolism, TCA cycle, Cell cycle, and Apoptosis pathways. Similarly, for the LNM comparison group, the DEKSs and related DEPs were primarily enriched in Hydrogen peroxide catabolic process and Tight junction pathway. Finally, according to The Cancer Genome Atlas Program (TCGA) database, the differential expression of Kcr DEPs were associated with the prognosis of thyroid cancer, indicating the prognostic significance of these proteins. Moreover, based on the clinical validation of 47 additional samples, Kcr was highly expressed in thyroid tumor tissues compared with normal tissue (t = 9.792, P < 0.001). In addition, a positive correlation was observed between Kcr and N-cadherin (r = 0.5710, P = 0.0015). Moreover, N-cadherin expression was higher in the relatively high Kcr expression group (χ2 = 18.966, P < 0.001). CONCLUSIONS: Higher Kcr expression was correlated with thyroid tumorigenesis and lymphatic metastasis, which may regulate thyroid cancer progression by Pyruvate metabolism, TCA cycle, Cell cycle, and other pathways.

Exploring the potential of myo-inositol in thyroid disease management: focus on thyroid cancer diagnosis and therapy.

Thyroid cancer (TC) is a malignancy that is increasing in prevalence on a global scale, necessitating the development of innovative approaches for both diagnosis and treatment. Myo-inositol (MI) plays a crucial role in a wide range of physiological and pathological functions within human cells. To date, studies have investigated the function of MI in thyroid physiology as well as its potential therapeutic benefits for hypothyroidism and autoimmune thyroiditis. However, research in the field of TC is very restricted. Metabolomics studies have highlighted the promising diagnostic capabilities of MI, recognizing it as a metabolic biomarker for identifying thyroid tumors. Furthermore, MI can influence therapeutic characteristics by modulating key cellular pathways involved in TC. This review evaluates the potential application of MI as a naturally occurring compound in the management of thyroid diseases, including hypothyroidism, autoimmune thyroiditis, and especially TC. The limited number of studies conducted in the field of TC emphasizes the critical need for future research to comprehend the multifaceted role of MI in TC. A significant amount of research and clinical trials is necessary to understand the role of MI in the pathology of TC, its diagnostic and therapeutic potential, and to pave the way for personalized medicine strategies in managing this intricate disease.

Thyroid Cancer With Autocrine Sialyl-fibronectin Depletion Has a Poor Prognosis due to EMT Progression.

BACKGROUND/AIM: Elevated blood fibronectin (FN) levels have been observed in various cancers; however, their significance remains controversial. Herein, we measured the levels of sialyl-fibronectin (S-FN), a type of FN secreted by tumor cells, and investigated whether blood S-FN secretion is associated with recurrent metastasis and epithelial-mesenchymal transition (EMT). PATIENTS AND METHODS: An ELISA system recognizing S-FN was constructed, and the amount of S-FN in blood samples from 63 patients with thyroid carcinoma was measured. The relationship between S-FN secretion and clinical prognosis was also examined. Vimentin immunostaining was performed to identify the mesenchymal status of the cells during EMT. RESULTS: After 12 years of observation, 17/63 patients had recurrent metastases, including nine cases of lymph node recurrence (LNR) and eight cases of remote metastasis (RM). LNR occurred in 7/39 (17.9%) of S-FN-negative cases, where 4/7 (57.1%) had two or more repeat recurrences. In S-FN-positive cases, LNR was observed in 2/24 cases (8.3%), and no repeat recurrence was observed. For RM, 6/39 (15.4%) patients were S-FN-negative, of which 5/6 (83.3%) had progressive disease even during treatment at metastasis. Of the S-FN-positive cases, RM was observed in 2/24 (8.3%) patients; progressive disease was observed in 1/2 (50.0%) patients. In 9/11 S-FN-negative recurrent metastasis cases (81.8%) and 2/4 S-FN-positive cases (50.0%), many vimentin-positive, FN-secreting cells were found in the interstitial tissue around the tumor. CONCLUSION: S-FN-negative thyroid cancer has a poor prognosis because of the progression of EMT associated with increased paracrine FN levels in the stroma.

Decreased sirtuin 4 levels promote cellular proliferation and invasion in papillary thyroid carcinoma.

Objective: This study examined the effect of sirtuin 4 (SIRT4), a NAD+-dependent deacetylase, on the proliferation and progression of papillary thyroid carcinoma (PTC). Methods: Data from The Cancer Genome Atlas (TCGA) were analyzed to identify SIRT4 expression in thyroid cancer. Subsequently, the correlation between SIRT4 expression and clinical characteristics was examined in 205 PTC tissue samples. In vitro assays using three human thyroid cancer cell lines (B-CPAP, TPC-1, and SNU-790) were conducted to assess the effects of regulated SIRT4 expression on cell growth, apoptosis, invasion, and migration. Furthermore, in vivo experiments were performed in a xenograft mouse model. Results: Gene Expression Omnibus (GEO) and TCGA data indicated that SIRT4 expression is lower in thyroid cancer and SIRT4 downregulation is associated with poor overall survival. In PTC tissues, positive SIRT4 expression was associated with decreased extracapsular extension. In in vitro experiments using three human thyroid cancer cell lines, overexpression of SIRT4 decreased cell survival, clonogenic potential, and invasion and migratory capabilities, as well as inducing apoptosis and increasing reactive oxygen species levels. SIRT4 overexpression upregulated E-cadherin and downregulated N-cadherin, suggesting its potential involvement in the regulation of epithelial-mesenchymal transition. These findings were confirmed in vivo using a xenograft mouse model. Conclusion: This study provides novel insight into the potential contribution of SIRT4 to the regulation of the pathological progression of PTC. The data suggest that SIRT4 plays a tumor-suppressive role in PTC by inhibiting growth, survival, and invasive potential. Future research should investigate the molecular mechanisms underlying these effects of SIRT4.

CCT2 Regulates ZEB1-Induced EMT Gene Transcription to Promote the Metastasis and Tumorigenesis of Papillary Thyroid Carcinoma.

BACKGROUND: Papillary thyroid carcinoma (PTC) is the most common malignant tumor of the thyroid, and its invasiveness and metastatic ability are closely related to patient prognosis. Chaperonin containing TCP1 subunit 2 (CCT2) is an important component of the molecular chaperone protein complex and has been shown to regulate cell proliferation and migration in various tumors. Epithelial-mesenchymal transition (EMT) is a critical process in tumor metastasis, and Zinc Finger E-Box Binding Homeobox 1 (ZEB1) is a core transcription factor that regulates EMT. This study aims to explore how CCT2 induces EMT gene transcription through ZEB1, thereby promoting the metastasis and tumorigenesis of PTC. METHODS: CCT2 in PTC tissues was analyzed using quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot. siRNA and overexpression vectors were used to silence and overexpress CCT2, respectively, and the effects on PTC cell migration, invasion, proliferation, and apoptosis were observed. Rescue experiments were used to investigate the effect of CCT2 on ZEB1 and EMT-related genes. Cell apoptosis was detected by Terminal deoxynucleotidyl transferase dUTP Nick End Labeling (TUNEL) assay. Silencing ZEB1 was used to verify its effect on the oncogenic activity of CCT2. RESULTS: CCT2 was found to be highly expressed in PTC tissues (p < 0.01). In in vitro and in vivo experiments, silencing CCT2 inhibited the migration and invasion of PTC cells and their metastasis, while overexpression of CCT2 produced the opposite effect. Additionally, CCT2 promoted PTC cell proliferation and inhibited apoptosis (p < 0.01). Mechanistic studies revealed that CCT2 upregulated ZEB1 expression (p < 0.01), thereby inducing EMT gene transcription (p < 0.01). Silencing ZEB1 reduced the oncogenic effect of CCT2. CONCLUSION: This study first revealed the high expression of CCT2 in PTC and its essential role in the migration, invasion, proliferation, and anti-apoptosis of tumor cells. CCT2 promotes the metastasis and tumorigenesis of PTC by regulating ZEB1 and EMT-related genes. These findings provide new potential targets for molecular targeted therapy of PTC and explore new directions for future clinical treatment strategies.

Pan-cancer analysis of the immunological and oncogenic roles of ATAD2 with verification in papillary thyroid carcinoma.

ATAD2 (ATPase Family AAA Domain-Containing 2) is highly expressed across varies tumor types, yet its common roles in tumor progression and immune interaction remain unclear. We analyzed the expression and alteration profiles of ATAD2, along with its diagnostic and prognostic role in pan-cancer, utilizing TCGA, GTEx, CPTAC, HPA, and cBioPortal databases. Furthermore, we examined the relationship between ATAD2 and immune infiltration utilizing single-cell sequencing data and TCGA database. Additionally, the expression and oncogenic functions of ATAD2 were verified in papillary thyroid carcinoma (PTC) through MTT, wound-healing, transwell, and flow cytometry assays. Our results revealed significant overexpression of ATAD2 in most cancers, strongly associated with poor prognosis. Amplification was the most frequent alteration type of ATAD2, with its mutation correlating with improved overall survival. ATAD2 was positively correlated with multiple inhibitory immune checkpoints and closely associated with the immunosuppressive microenvironment, particularly in PTC. In vitro experiments demonstrated that ATAD2 promoted the proliferation, migration, and invasion of PTC cells by activating the PI3K-AKT pathway and modulating the G1/S cell cycle checkpoint. Collectively, ATAD2 holds promise as a biomarker for pan-cancer diagnosis and prognosis, as well as a predictor of immunotherapeutic responsiveness and a therapeutic target to enhance the efficacy of existing anti-tumor immune therapies.

Maintenance of magnesium homeostasis by NUF2 promotes protein synthesis and anaplastic thyroid cancer progression.

Thyroid cancer is the most frequently observed endocrine-related malignancy among which anaplastic thyroid cancer (ATC) is the most fatal subtype. The synthesis of protein is active to satisfy the rapid growth of ATC tumor, but the mechanisms regulating protein synthesis are still unknown. Our research revealed that kinetochore protein NUF2 played an essential role in protein synthesis and drove the progression of ATC. The prognosis of patients with thyroid carcinoma was positively correlated with high NUF2 expression. Depletion of NUF2 in ATC cells notably inhibited the proliferation and induced apoptosis, while overexpression of NUF2 facilitated ATC cell viability and colony formation. Deletion of NUF2 significantly suppressed the growth and metastasis of ATC in vivo. Notably, knockdown of NUF2 epigenetically inhibited the expression of magnesium transporters through reducing the abundance of H3K4me3 at promoters, thereby reduced intracellular Mg2+ concentration. Furthermore, we found the deletion of NUF2 or magnesium transporters significantly inhibited the protein synthesis mediated by the PI3K/Akt/mTOR pathway. In conclusion, NUF2 functions as an emerging regulator for protein synthesis by maintaining the homeostasis of intracellular Mg2+, which finally drives ATC progression.

MicroRNA Profiling in Papillary Thyroid Cancer.

Genetic alterations are well known to be related to the pathogenesis and prognosis of papillary thyroid carcinoma (PTC). Some miRNA expression dysregulations have previously been described in the context of cancer development including thyroid carcinoma. In our study, we performed original molecular diagnostics on tissue samples related to our own patients. We aimed to identify all dysregulated miRNAs in potential association with PTC development via sequencing much higher numbers of control-matched PTC tissue samples and analyzing a wider variety of miRNA types than previous studies. We analyzed the expression levels of 2656 different human miRNAs in the context of 236 thyroid tissue samples (118 tumor and control pairs) related to anonymized PTC cases. Also, KEGG pathway enrichment analysis and GO framework analysis were used to establish the links between miRNA dysregulation and certain biological processes, pathways of signaling, molecular functions, and cellular components. A total of 30 significant differential miRNA expressions with at least ±1 log2 fold change were found related to PTC including, e.g., miR-551b, miR-146b, miR-221, miR-222, and miR-375, among others, being highly upregulated, as well as miR-873 and miR-204 being downregulated. In addition, we identified miRNA patterns in vast databases (KEGG and GO) closely similar to that of PTC including, e.g., miRNA patterns of prostate cancer, HTLV infection, HIF-1 signaling, cellular responses to growth factor stimulus and organic substance, and negative regulation of gene expression. We also found 352 potential associations between certain miRNA expressions and states of clinicopathological variables. Our findings-supported by the largest case number of original matched-control PTC-miRNA relation research-suggest a distinct miRNA expression profile in PTC that could contribute to a deeper understanding of the underlying molecular mechanisms promoting the pathogenesis of the disease. Moreover, significant miRNA expression deviations and their signaling pathways in PTC presented in our study may serve as potential biomarkers for PTC diagnosis and prognosis or even therapeutic targets in the future.

COL4A2 enhances thyroid cancer cell proliferation through the AKT pathway.

Objectives: Thyroid cancer (THCA) is the most common malignant tumor in endocrine system and the incidence has been increasing worldwide. And the number of patients dying from THCA has also gradually risen because the incidence continues to increase, so the mechanisms related to effective targets is necessary to improve the survival. This study was to preliminarily investigate the effects of the COL4A2 gene on the regulation of thyroid cancer (THCA) cell proliferation and the associated pathways. Methods: Bioinformatics analysis revealed that COL4A2 was closely associated with cancer development. COL4A2 expression in THCA tissues was analyzed using immunohistochemistry, and survival information was determined via Kaplan‒Meier curves. The expression of COL4A2 and AKT pathway-related genes were analyzed using qPCR and western blot analyses. Colony formation as well as CCK-8 assays exhibited the cell proliferation level and cell activity, respectively. Downstream of COL4A2 was identified by Gene set enrichment analysis (GSEA). The effects of the COL4A2 and AKT pathways on THCA tumor growth in vivo were determined using a mouse model. Results: Bioinformatics analysis exhibited that COL4A2 plays a significant role in cancer and that the AKT pathway is downstream of COL4A2. THCA patients with high COL4A2 expression had shorter recurrence-free survival. Upregulation of COL4A2 gene expression in 2 THCA cell lines promoted tumor cell growth and activity. The use of AKT pathway blockers also restrained the growth and activity of the 2 THCA cell lines. The use of AKT pathway blockers reduced tumor volume and mass and prolonged mouse survival. Conclusions: COL4A2 can promote the growth as well as development of THCA through the AKT pathway and COL4A2 could be used as a target for THCA.

SPRED3 regulates the NF-κB signaling pathway in thyroid cancer and promotes the proliferation.

SPRED3 (Sprouty-related EVH1 domain containing 3) mutants are depicted in various cancers, however, nothing is known about its biofunction in thyroid cancer (THCA). Bioinformatic analyses were conducted to ascertain the level of SPRED3 expression in THCA tissues and its importance in the prognosis of THCA patients. Flag-SPRED3 plasmid and SPRED3-knockout vector were developed to overexpress or deplete the SPRED3 expression in THCA cells. The function of SPRED3 on THCA cell proliferation was examined using the colony formation assay and CCK8 assay. The effect of SPRED3 expression on the transcriptional activity of NF-κB was also examined using luciferase reporter assays. High SPRED3 expression was associated with unfavorable clinical outcomes, advanced tumor characteristics, and traditional molecular markers of papillary thyroid cancer in THCA patients. Genetic analysis revealed differences in mutation rates in key genes between SPRED3-high and SPRED3-low THCA cases. It is also revealed that SPRED3 influenced the immune microenvironment, with increased stromal and immune scores and altered immune cell infiltration. Functionally, SPRED3 overexpression enhanced THCA cell viability and colony formation, while its depletion reduced cell growth and proliferation. In vivo experiments in mice confirmed the inhibitory effect of SPRED3 depletion on tumor growth. Mechanically, we found that SPRED3 activated the NF-κB signaling. For the first time, we found that SPRED3 promotes THCA cell proliferation via the NF-κB signaling pathway. This finding may provide insight into SPRED3's prognostic potential in thyroid cancer and provide the rationale for SPRED3-targeted druggable interventions.

KLHDC8A Regulates M1/M2 Macrophage Polarization Through the PD-1/STAT3 Pathway to Promote Papillary Thyroid Cancer Development.

BACKGROUND: Papillary thyroid cancer (PTC) is one of the most frequent endocrine malignancies. Kelch domain containing 8A (KLHDC8A) is reported as an epigenetically driven oncogene, but the role of KLHDC8A in PTC is still unclear. This study aimed to explore the function of KLHDC8A in PTC progression. METHODS: KLHDC8A expression was analyzed by the Gene Expression Profiling Interactive Analysis (GEPIA) website, quantitative real-time PCR (qRT-PCR), and western blot. The viability of PTC cells (TPC-1 and BCPAP) was assessed by cell counting kit-8 (CCK-8) kit. A transwell assay was carried out to evaluate the invasion and migration of PTC cells. Macrophage polarization-associated markers were determined by qRT-PCR and western blot. Mice tumor xenograft models were established to analyze the role of KLHDC8A in vivo. Pathway-related proteins (programmed cell death protein 1 (PD-1) and signal transducer and activator of transcription 3 (STAT3)) were determined by western blot. RESULTS: GEPIA demonstrated that KLHDC8A was highly expressed in PTC (p < 0.05). Knockdown of KLHDC8A hindered cell viability, invasion, and migration of PTC cells (p < 0.0001). Additionally, KLHDC8A knockdown inhibited M2 polarization while promoting M1 polarization (p < 0.0001). Meanwhile, KLHDC8A silencing inhibited tumor growth in mice xenografted models (p < 0.0001). Moreover, the PD-1/STAT3 pathway was suppressed by KLHDC8A silencing (p < 0.01), and the STAT3 activator (colivelin) attenuated the inhibitory effects of KLHDC8A silencing on PTC progression (p < 0.01). CONCLUSIONS: Through in vivo and in vitro experiments, KLHDC8A silencing could restrain PTC cell viability, migration, and invasion, inhibit tumor growth, and promote M1 polarization via the PD-1/STAT3 axis, providing a new therapeutic idea for PTC clinical treatment.

Effect of PGE2 on TT cells viability and division.

Previous studies have shown prostaglandin E2 (PGE2) produced a marked increase in calcitonin secretion in human C-cells derived from medullary thyroid carcinoma. However, it's unclear whether PGE2 can increase the growth of C cells. In this study, we use TT cells as a C cell model to investigate the effect of PGE2 on the growth of C cells. The results revealed that both PGE2 and arachidonic acid (AA) significantly increased the count of TT cells, whereas indomethacin and Dup697 reduced this count. Notably, an increase in the level of AA was associated with an increase in the number of proliferating TT cells, indicating a dose-response relationship. PGE2 and its receptor agonists (sulprostone and butaprost) enhanced the proliferation of TT cells. By contrast, 17-phenyl-trinor-PGE2 exerted no significant effect on TT cell proliferation, whereas L161982 suppressed it. The positive effect of AA on TT cell proliferation was inhibited by indomethacin, NS398, Dup697 (complete inhibition), and SC560. Both PGE2 and AA increased the level of p-STAT5a. The positive effect of AA on p-STAT5a was completely inhibited by Dup697 but not indomethacin, NS398, or SC560. Treatment with indomethacin or Dup697 alone reduced the level of STAT5a in TT cells. AA increased the level of STAT5a, but this effect was inhibited by indomethacin, NS398, and Dup697. Overall, this study confirms the effect of PGE2 on the proliferation of TT cells. This effect is likely mediated through EP2, EP3, and EP4 receptors and associated with an increase in p-STAT5a level within TT cells.

UBR1 promotes anaplastic thyroid carcinoma progression via stabilizing YAP through monoubiquitylation.

Anaplastic thyroid carcinoma (ATC) is a highly aggressive human malignancy without effective treatment. Yes-associated protein (YAP) is a critical effector of the Hippo pathway, which is essential in thyroid carcinogenesis. However, the underlying mechanisms of aberrant YAP expression in ATC are not completely understood. Ubiquitylation-related enzyme siRNA screening identified the ubiquitin protein ligase E3 component n-recognin 1 (UBR1) as a stabilizer of YAP in ATC cells. UBR1 deficiency reduced YAP protein levels and its target gene expression. UBR1 directly interacted with YAP and promoted its monoubiquitylation, competitively suppressing its polyubiquitylation and resulting in extended protein half-life. UBR1 depletion reduced ATC cell proliferation and migration in vitro. Xenograft tumor studies also suggested that UBR1 knockdown suppressed ATC cell growth in vivo. Furthermore, exogenous YAP expression partially reversed the inhibitive effects of UBR1 depletion on ATC cell proliferation and migration. Our studies demonstrated that UBR1 directly interacts with YAP and stabilized it in a monoubiquitylation-dependent manner, consequently promoting ATC tumorigenesis, suggesting that UBR1 might be a potentially therapeutic target for ATC treatment.

ACAP3 negatively regulated by HDAC2 inhibits the malignant development of papillary thyroid carcinoma cells.

ArfGAP with coiled-coil, ankyrin repeat and PH domains 3 (ACAP3) level has been confirmed to be downregulated in papillary thyroid carcinoma (PTC). Histone deacetylase inhibitors (HDACIs) have therapeutic effects on PTC. Accordingly, this study probed into the potential relation of histone deacetylase 2 (HDAC2) and ACAP3 in PTC. Expressions of ACAP3 and HDAC2 in PTC were investigated by quantitative real-time polymerase chain reaction (qRT-PCR). The relationship between HDAC2 and ACAP3 was predicted by Pearson analysis. Cell functional assays (cell counting kit-8, transwell, wound healing and flow cytometry assays) and rescue assay were carried out to determine the effects of HDAC2/ACAP3 axis on biological behaviors of PTC cells. Expressions of apoptosis-, epithelial-mesenchymal transition-, Protein Kinase B (AKT)-, and P53-related proteins were measured by Western blot. ACAP3 level was downregulated in PTC tissues and cells. ACAP3 overexpression (oe-ACAP3) suppressed viability, proliferation, migration and invasion of PTC cells, facilitated apoptosis, downregulated the expressions of Protein Kinase B (Bcl-2) and N-cadherin, upregulated the expressions of Bcl-2 associated protein X (Bax) and E-cadherin, diminished the p-AKT/AKT ratio and elevated the p-p53/p53 ratio; however, ACAP3 silencing or HDAC2 overexpression (oe-HDAC2) did the opposite. HDAC2 negatively correlated with ACAP3. The tumor-suppressing effect of oe-ACAP3 in PTC was reversed by oe-HDAC2. Collectively, ACAP3 negatively regulated by HDAC2 suppresses the proliferation and metastasis while facilitating apoptosis of PTC cells.