Hsa_circ_0058124 promotes papillary thyroid cancer tumorigenesis and invasiveness through the NOTCH3/GATAD2A axis

hsa_circ_0101050 regulated by ZC3H13 enhances tumorigenesis in papillary thyroid cancer via m6A modification

While the regulatory roles of circular RNAs (circRNAs) and zinc finger CCCH-type containing 13 (ZC3H13) were previously reported in various human cancers, the mechanisms underlying their interaction in papillary thyroid cancer (PTC) remain unclear. We aimed to determine the role of hsa_circ_0101050 and its regulatory relationship with ZC3H13 in PTC. The expression levels of hsa_circ_0101050 and ZC3H13 were determined in tumor samples and adjacent normal tissues from 46 patients with PTC and in two PTC cell lines (IHH-4 and PTC-1) using quantitative reverse transcription-polymerase chain reaction. The roles of hsa_circ_0101050 and ZC3H13 in cell viability, wound healing, and migration were determined using knockdown and overexpression approaches in PTC cell lines, and a xenograft model in nude mice was used to determine their role in vivo. Methylated RNA immunoprecipitation assay was used to analyze N6-methyladenosine (m6A) modification of hsa_circ_0101050 by ZC3H13. We found hsa_circ_0101050 overexpression and ZC3H13 downregulation in PTC samples and PTC cell lines. In PTC cell lines, silencing hsa_circ_0101050 reduced cell viability and migration whereas its overexpression promoted an aggressive PTC phenotype. ZC3H13 increased the m6A modification of hsa_circ_0101050 and repressed its expression. ZC3H13 overexpression inhibited PTC cell viability, migration, and invasion, which were reversed in cells overexpressing hsa_circ_0101050. Taken together, these results suggested that the downregulation of hsa_circ_0101050 mediated by ZC3H13 through m6A modification contributed to its oncogenic effect in PTC development, revealing the ZC3H13-m6A-hsa_circ_0101050 as a potential therapeutic target in PTC.

Circ_0004851 regulates the molecular mechanism of miR-296-3p/FGF11 in the influence of high iodine on PTC

The prevalence of papillary thyroid cancer (PTC) has been rising in recent years. Despite its relatively low mortality, PTC frequently metastasizes to lymph nodes and often recurs, posing significant health and economic burdens. The role of iodine in the pathogenesis and advancement of thyroid cancer remains poorly understood. Circular RNAs (circRNAs) are recognized to function as competing endogenous RNAs (ceRNAs) that modulate gene expression and play a role in various cancer stages. Consequently, this research aimed to elucidate the mechanism by which circRNA influences the impact of iodine on PTC. Our research indicates that high iodine levels can exacerbate the malignancy of PTC via the circ_0004851/miR-296-3p/FGF11 axis. These insights into iodine's biological role in PTC and the association of circRNA with the disease could pave the way for novel biomarkers and potentially effective therapeutic strategies to mitigate PTC progression.

Identification and validation of a prognostic anoikis-related gene signature in papillary thyroid carcinoma by integrated analysis of single-cell and bulk RNA-sequencing

Papillary thyroid carcinoma (PTC) prognosis may be deteriorated due to the metastases, and anoikis palys an essential role in the tumor metastasis. However, the potential effect of anoikis-related genes on the prognosis of PTC was unclear. The mRNA and clinical information were obtained from the cancer genome atlas database. Hub genes were identified and risk model was constructed using Cox regression analysis. Kaplan-Meier (K-M) curve was applied for the survival analysis. Immune infiltration and immune therapy response were calculated using CIBERSORT and TIDE. The identification of cell types and cell interaction was performed by Seurat, SingleR and CellChat packages. GO, KEGG, and GSVA were applied for the enrichment analysis. Protein-protein interaction network was constructed in STRING and Cytoscape. Drug sensitivity was assessed in GSCA. Based on bulk RNA data, we identified 4 anoikis-related risk signatures, which were oncogenes, and constructed a risk model. The enrichment analysis found high risk group was enriched in some immune-related pathways. High risk group had higher infiltration of Tregs, higher TIDE score and lower levels of monocytes and CD8 T cells. Based on scRNA data, we found that 4 hub genes were mainly expressed in monocytes and macrophages, and they interacted with T cells. Hub genes were significantly related to immune escape-related genes. Drug sensitivity analysis suggested that cyclin dependent kinase inhibitor 2A may be a better chemotherapy target. We constructed a risk model which could effectively and steadily predict the prognosis of PTC. We inferred that the immune escape may be involved in the development of PTC.

Hsa_circ_0092355 Accelerates Papillary Thyroid Cancer Progression by Regulating the miR-543/PDE5A Pathway

CircRNAs have been found to participate in the progression of various tumors. In the present study, we aimed to clarify the role of hsa_circ_0092355 in papillary thyroid cancer (PTC) cell development. RT-qPCR was used to determine the expression of hsa_circ_0092355, miR-543, and PDE5A. PTC cell proliferation was ascertained via a cell colony formation assay and the CCK-8 test. Western blotting was performed to examine the expression levels of PDE5A and apoptosis-associated proteins (Bcl-2 and Bax) in PTC cells. A scratch wound assay was performed to measure the migration of PTC cells. A mouse xenograft test was performed to assess the effects of hsa_circ_0092355 in vivo. RIP and dual-luciferase reporter assays confirmed the association between miR-543 and hsa_circ_0092355 or PDE5A. Associations between miR-543, hsa_circ_0092355, and PDE5A were evaluated using Pearson's correlation coefficient. Upregulation of hsa_circ_0092355 was observed in PTC tissues. The hsa_circ_0092355 knockdown blocked the proliferation and migration of PTC cells and induced apoptosis. Moreover, hsa_circ_0092355 knockdown blocked PTC xenograft tumor growth in vivo. The miR-543 inhibitor could reverse the changes induced by hsa_circ_0092355 knockdown by hsa_circ_0092355 targeting miR-543. Furthermore, miR-543 suppresses PTC progression by downregulating PDE5A expression. Our findings suggest that the PTC tumor promoter hsa_circ_0092355 may promote carcinogenesis by controlling the miR-543/PDE5A pathway.

CircNRCAM up-regulates NRCAM to promote papillary thyroid carcinoma progression

PURPOSE

Papillary Thyroid Carcinoma (PTC) is the most prevalent subtype of Thyroid Carcinoma (THCA), a type of malignancy in the endocrine system. According to prior studies, Neural Cell Adhesion Molecule (NRCAM) has been found to be up-regulated in PTC and stimulates the proliferation and migration of PTC cells. However, the specific mechanism of NRCAM in PTC cells is not yet fully understood. Consequently, this study aimed to investigate the underlying mechanism of NRCAM in PTC cells, the findings of which could provide new insights for the development of potential treatment targets for PTC.

METHODS AND RESULTS

Bioinformatics tools were utilized and a series of experiments were conducted, including Western blot, colony formation, and dual-luciferase reporter assays. The data collected indicated that NRCAM was overexpressed in THCA tissues and PTC cells. Circular RNA NRCAM (circNRCAM) was found to be highly expressed in PTC cells and to positively regulate NRCAM expression. Through loss-of-function assays, both circNRCAM and NRCAM were shown to promote the proliferation, invasion, and migration of PTC cells. Mechanistically, this study confirmed that precursor microRNA-506 (pre-miR-506) could bind with m6A demethylase AlkB Homolog 5 (ALKBH5), leading to its m6A demethylation. It was also discovered that circNRCAM could competitively bind to ALKBH5, which restrained miR-506-3p expression and promoted NRCAM expression.

CONCLUSION

In summary, circNRCAM could up-regulate NRCAM by down-regulating miR-506-3p, thereby enhancing the biological behaviors of PTC cells.

Emerging roles of circular RNAs in regulating the hallmarks of thyroid cancer

Thyroid cancer is a prevalent endocrine malignancy with increasing incidence in recent years. Although most thyroid cancers grow slowly, they can become refractory, leading to a high mortality rate once they exhibit recurrence, metastasis, resistance to radioiodine therapy, or a lack of differentiation. However, the mechanisms underlying these malignant characteristics remain unclear. Circular RNAs, a type of closed-loop non-coding RNAs, play multiple roles in cancer. Several studies have demonstrated that circular RNAs significantly influence the development of thyroid cancers. In this review, we summarize the circular RNAs identified in thyroid cancers over the past decade according to the hallmarks of cancer. We found that eight of the 14 hallmarks of thyroid cancers are regulated by circular RNAs, whereas the other six have not been reported to be correlated with circular RNAs. This review is expected to help us better understand the roles of circular RNAs in thyroid cancers and accelerate research on the mechanisms and cure strategies for thyroid cancers.

Circular RNAs: characteristics, functions, mechanisms, and potential applications in thyroid cancer

Thyroid cancer (TC) is one of the most common endocrine malignancies, and its incidence has increased globally. Despite extensive research, the underlying molecular mechanisms of TC remain partially understood, warranting continued exploration of molecular markers for diagnostic and prognostic applications. Circular RNAs (circRNAs) have recently garnered significant attention owing to their distinct roles in cancers. This review article introduced the classification and biological functions of circRNAs and summarized their potential as diagnostic and prognostic markers in TC. Further, the interplay of circRNAs with PI3K/Akt/mTOR, Wnt/β-catenin, MAPK/ERK, Notch, JAK/STAT, and AMPK pathways is elaborated upon. The article culminates with an examination of circRNA's role in drug resistance of TC and highlights the challenges in circRNA research in TC.

Dysregulated Expression Patterns of Circular RNAs in Cancer: Uncovering Molecular Mechanisms and Biomarker Potential

Circular RNAs (circRNAs) are stable, enclosed, non-coding RNA molecules with dynamic regulatory propensity. Their biogenesis involves a back-splicing process, forming a highly stable and operational RNA molecule. Dysregulated circRNA expression can drive carcinogenic and tumorigenic transformation through the orchestration of epigenetic modifications via extensive RNA and protein-binding domains. These multi-ranged functional capabilities have unveiled extensive identification of previously unknown molecular and cellular patterns of cancer cells. Reliable circRNA expression patterns can aid in early disease detection and provide criteria for genome-specific personalized medicine. Studies described in this review have revealed the novelty of circRNAs and their biological ss as prognostic and diagnostic biomarkers.

CircSEMA6A upregulates PRRG4 by targeting MiR-520h and recruiting ELAVL1 to affect cell invasion and migration in papillary thyroid carcinoma

Objective

As the most prevalent type of thyroid malignancy, papillary thyroid carcinoma (PTC) accounts for over 80% of all thyroid cancers. Circular RNAs (circRNAs) have been found to regulate multiple cancers, including PTC.

Materials and methods

Quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting were used to analyse RNA and protein levels. Fluorescence in situ hybridization (FISH) was used to detect the distribution of the target genes. Functional experiments and animal experiments were implemented to analyse the biological functions of target genes in vitro and in vivo. Luciferase reporter, RNA pulldown, RNA binding protein immunoprecipitation (RIP) and mRNA stability assays were used to probe the underlying mechanisms.

Results

CircSEMA6Awas found to be upregulated in PTC tissues and cells, and its circular structure was verified. CircSEMA6A promotes PTC cell migration and invasion. Moreover, circSEMA6A functions as a competing endogenous RNA (ceRNA) to upregulate proline rich and Gla domain 4 (PRRG4) expression by sponging microRNA-520h (miR-520h). CircSEMA6A recruits ELAV1 to stabilize PRRG4 mRNA and drives PTC progression via PRRG4.

Conclusion

CircSEMA6A upregulates PRRG4 by targeting miR-520h and recruiting ELAVL1 to affect the invasion and migration of PTC cells, offering insight into the molecular mechanisms of PTC.

Identification and clinical value of a new ceRNA axis (TIMP3/hsa-miR-181b-5p/PAX8-AS1) in thyroid cancer

Background

Thyroid cancer (TC) is a prevalent and increasingly common malignant tumor. In most cases, TC progresses slowly and runs a virtually benign course. However, challenges remain with the treatment of refractory TC, which does not respond to traditional management or is subject to relapse or metastasis. Therefore, new therapeutic regimens for TC patients with poor outcomes are urgently needed.

Methods

The differentially expressed RNAs were identified from the expression profile data of RNA from TC downloaded from The Cancer Genome Atlas database. Multiple databases were utilized to investigate the regulatory relationship among RNAs. Subsequently, a competitive endogenous RNA (ceRNA) network was established to elucidate the ceRNA axis that is responsible for the clinical prognosis of TC. To understand the potential mechanism of ceRNA axis in TC, location analysis, functional enrichment analysis, and immune-related analysis were conducted.

Results

A ceRNA network of TC was constructed, and the TIMP3/hsa-miR-181b-5p/PAX8-AS1 ceRNA axis associated with the prognosis of TC was successfully identified. Our results showed that the axis might influence the prognosis of TC through its regulation of regulating tumor immunity.

Conclusions

Our findings provide evidence that TIMP3/hsa-miR-181b-5p/PAX8-AS1 axis is significantly related to the prognosis of TC. The molecules involved in this axis may serve as novel therapeutic approaches for TC treatment.

Emerging roles of circular RNAs in the invasion and metastasis of head and neck cancer: Possible functions and mechanisms

Head and neck cancer (HNC) is the seventh most prevalent malignancy worldwide in 2020. Cancer metastasis is the main cause of poor prognosis in HNC patients. Recently, circular RNAs (circRNAs), initially thought to have no biological function, are attracting increasing attention, and their crucial roles in mediating HNC metastasis are being extensively investigated. Existing studies have shown that circRNAs primarily function through miRNA sponges, transcriptional regulation, interacting with RNA-binding proteins (RBPs) and as translation templates. Among these functions, the function of miRNA sponge is the most prominent. In this review, we summarized the reported circRNAs involved in HNC metastasis, aiming to elucidate the regulatory relationship between circRNAs and HNC metastasis. Furthermore, we summarized the latest advances in the epidemiological information of HNC metastasis and the tumor metastasis theories, the biogenesis, characterization and functional mechanisms of circRNAs, and their potential clinical applications. Although the research on circRNAs is still in its infancy, circRNAs are expected to serve as prognostic markers and effective therapeutic targets to inhibit HNC metastasis and significantly improve the prognosis of HNC patients.

Suppressing circIDE/miR-19b-3p/RBMS1 axis exhibits promoting-tumour activity through upregulating GPX4 to diminish ferroptosis in hepatocellular carcinoma

Ferroptosis is a newly characterized form of iron-dependent non-apoptotic cell death, which is closely associated with cancer progression. However, the functions and mechanisms in regulation of escaping from ferroptosis during hepatocellular carcinoma (HCC) progression remain unknown. In this study, we reported that the RNA binding motif single stranded interacting protein 1 (RBMS1) participated in HCC development，and functioned as a regulator of ferroptosis. Clinically, the downregulation of RBMS1 occurred in HCC tissues, and low RBMS1 expression was associated with worse HCC patients survival. Mechanistically, RBMS1 overexpression inhibited HCC cell growth by attenuating the expression of glutathione peroxidase 4 (GPX4)and further facilitated ferroptosis in vitro and in vivo. More importantly, a novel circIDE (hsa_circ_0000251) was identified to elevate RBMS1 expression via sponging miR-19b-3p in HCC cells. Collectively, our findings established circIDE/miR-19b-3p/RBMS1 axis as a regulator of ferroptosis, which could be a promising therapeutic target and prognostic factor.

Hypoxic papillary thyroid carcinoma cells-secreted exosomes deliver miR-221-3p to normoxic tumor cells to elicit a pro-tumoral effect by regulating the ZFAND5

Papillary thyroid cancer (PTC) has seen a worldwide expansion in incidence in the past three decades. Tumor-derived exosomes have been associated with the metastasis of cancer cells and are present within the local hypoxic tumor microenvironment, where they mediate intercellular communication by transferring molecules including microRNAs (miRNAs) between cells. Although miRNAs have been shown to serve as non-invasive biomarkers for cancer diagnosis, the role of hypoxia-induced tumor-derived exosomes in PTC progression remains unclear. Herein, we investigated the differentially expressed miRNA expression profiles from GEO datasets (GSE191117 and GSE151180) by using the DESeq package in R and identified a novel role for miR-221-3p as an oncogene in PTC development. In vivo and in vitro loss and gain assays were used to clarify the mechanism of hypoxic PTC cells derived exosomal-miR-221-3p in PTC. miR-221-3p was upregulated in human PTC plasma exosomes, tissues and cell lines. We found that hypoxic PTC cells derived exosomal-miR-221-3p promoted normoxic PTC cells proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) in vitro, while inhibition of miR-221-3p limited PTC tumor growth in our PTC xenograft model in nude mice. We finally identified ZFAND5, to be a miR-221-3p target. Mechanistically, hypoxic PTC cell lines-derived exosomes carrying miR-221-3p promoted PTC tumorigenesis by regulating ZFAND5. Our findings further the understanding of the underlying mechanisms associated with PTC progression and identify exosomal-miR-221-3p as a potential biomarker for the diagnosis and prognosis of PTC patients. Our study also suggests that miR-221-3p inhibitors could be a potential treatment strategy for PTC.

ANKRD22 knockdown suppresses papillary thyroid cell carcinoma growth and migration and modulates the Wnt/β-catenin signaling pathway

The incidence of thyroid cancer is escalating globally, particularly among women. Studies have demonstrated the abnormal activation of Ankyrin Repeat Domain 22 (ANKRD22) in various cancers, but it remains uncertain whether it is also highly expressed in papillary thyroid carcinoma (PTC). Our objective was to evaluate the role of ANKRD22 in PTC. The expression of ANKRD22 varies among tissues, as validated by the Cancer Genome Atlas, and further predicted using the Tumor Immune Estimation Resource. Predicted results were examined via polymerase chain reaction and western blotting. Subsequently, the expression of ANKRD22 in cells was suppressed by RNA interference, and changes in cell progression were examined in conjunction with the cell counting kit-8 assay, transwell assay, and colony formation assay. Finally, the effects of ANKRD22 knockdown on the Epithelial-to-Mesenchymal transition and the Wnt/β-catenin signaling pathway were investigated through western blotting. An in vivo mice model was established to validate the effect of ANKRD22. This study discovered that ANKRD22 was highly expressed in PTC, which was validated by polymerase chain reaction and western blotting. Knockdown of ANKRD22, significantly reduced thecell viability, colony formation capability, and cell invasion and migration abilities. Furthermore, we found that knockdown of ANKRD22 impaired both tumor Epithelial-to-Mesenchymal transition and the activation of the Wnt/β-catenin signaling pathway. In conclusion, this study revealed that the knockdown of ANKRD22 inhibits the growth and migration of papillary thyroid cell carcinoma by regulating the Wnt/β-catenin signaling pathway.

circAGTPBP1 promotes the progression of papillary thyroid cancer through the notch pathway via the miR-34a-5p/notch1 axis

The dysregulation of circular RNAs (circRNAs) has been implicated in the development and progression of papillary thyroid cancer (PTC). In this study, we analyzed the dysregulated circRNA profile using PTC tissues and matched adjacent normal tissues by RNA-seq. We conducted in vitro and in vivo experiments to investigate the biological functions of circAGTPBP1 in PTC progression. We found that circAGTPBP1 was upregulated in PTC tissues and cell lines, and its expression was positively correlated with tumor size, lymph node metastasis, and clinical stage. Using RNA-seq and bioinformatic analysis, we identified miR-34a-5p and NOTCH1 as downstream targets of circAGTPBP1. Functionally, circAGTPBP1 knockdown significantly inhibited the migration, invasion, and metastasis of PTC cell lines in vitro, while the miR-34a-5p inhibitor reversed these effects. Additionally, circAGTPBP1 knockdown inhibited tumor growth in vivo. Our findings suggest that circAGTPBP1 may act as a tumor promoter and could be a potential therapeutic target for PTC.

Three-dimensional ultrasound-based radiomics nomogram for the prediction of extrathyroidal extension features in papillary thyroid cancer

Purpose

To develop and validate a three-dimensional ultrasound (3D US) radiomics nomogram for the preoperative prediction of extrathyroidal extension (ETE) in papillary thyroid cancer (PTC).

Methods

This retrospective study included 168 patients with surgically proven PTC (non-ETE, n = 90; ETE, n = 78) who were divided into training (n = 117) and validation (n = 51) cohorts by a random stratified sampling strategy. The regions of interest (ROIs) were obtained manually from 3D US images. A larger number of radiomic features were automatically extracted. Finally, a nomogram was built, incorporating the radiomics scores and selected clinical predictors. Receiver operating characteristic (ROC) curves were performed to validate the capability of the nomogram on both the training and validation sets. The nomogram models were compared with conventional US models. The DeLong test was adopted to compare different ROC curves.

Results

The area under the receiver operating characteristic curve (AUC) of the radiologist was 0.67 [95% confidence interval (CI), 0.580-0.757] in the training cohort and 0.62 (95% CI, 0.467-0.746) in the validation cohort. Sixteen features from 3D US images were used to build the radiomics signature. The radiomics nomogram, which incorporated the radiomics signature, tumor location, and tumor size showed good calibration and discrimination in the training cohort (AUC, 0.810; 95% CI, 0.727-0.876) and the validation cohort (AUC, 0.798; 95% CI, 0.662-0.897). The result suggested that the diagnostic efficiency of the 3D US-based radiomics nomogram was better than that of the radiologist and it had a favorable discriminate performance with a higher AUC (DeLong test: p < 0.05).

Conclusions

The 3D US-based radiomics signature nomogram, a noninvasive preoperative prediction method that incorporates tumor location and tumor size, presented more advantages over radiologist-reported ETE statuses for PTC.

New biomarkers: prospect for diagnosis and monitoring of thyroid disease

After the metabolic syndrome and its components, thyroid disorders represent the most common endocrine disorders, with increasing prevalence in the last two decades. Thyroid dysfunctions are distinguished by hyperthyroidism, hypothyroidism, or inflammation (thyroiditis) of the thyroid gland, in addition to the presence of thyroid nodules that can be benign or malignant. Thyroid cancer is typically detected via an ultrasound (US)-guided fine-needle aspiration biopsy (FNAB) and cytological examination of the specimen. This approach has significant limitations due to the small sample size and inability to characterize follicular lesions adequately. Due to the rapid advancement of high-throughput molecular biology techniques, it is now possible to identify new biomarkers for thyroid neoplasms that can supplement traditional imaging modalities in postoperative surveillance and aid in the preoperative cytology examination of indeterminate or follicular lesions. Here, we review current knowledge regarding biomarkers that have been reliable in detecting thyroid neoplasms, making them valuable tools for assessing the efficacy of surgical procedures or adjunctive treatment after surgery. We are particularly interested in providing an up-to-date and systematic review of emerging biomarkers, such as mRNA and non-coding RNAs, that can potentially detect thyroid neoplasms in clinical settings. We discuss evidence for miRNA, lncRNA and circRNA dysregulation in several thyroid neoplasms and assess their potential for use as diagnostic and prognostic biomarkers.

Biological and therapeutic viewpoints towards role of miR-218 in human cancers: Revisiting molecular interactions and future clinical translations

Understanding the exact pathogenesis of cancer is difficult due to heterogenous nature of tumor cells and multiple factors that cause its initiation and development. Treatment of cancer is mainly based on surgical resection, chemotherapy, radiotherapy and their combination, while gene therapy has been emerged as a new kind of therapy for cancer. Post-transcriptional regulation of genes has been of interest in recent years and among various types of epigenetic factors that can modulate gene expression, short non-coding RNAs known as microRNAs (miRNAs) have obtained much attention. The stability of mRNA decreases by miRNAs to repress gene expression. miRNAs can regulate tumor malignancy and biological behavior of cancer cells and understanding their function in tumorigenesis can pave the way towards developing new therapeutics in future. One of the new emerging miRNAs in cancer therapy is miR-218 that increasing evidence highlights its anti-cancer activity, while a few studies demonstrate its oncogenic function. The miR-218 transfection is promising in reducing progression of tumor cells. miR-218 shows interactions with molecular mechanisms including apoptosis, autophagy, glycolysis and EMT, and the interaction is different. miR-218 induces apoptosis, while it suppresses glycolysis, cytoprotective autophagy and EMT. Low expression of miR-218 can result in development of chemoresistance and radio-resistance in tumor cells and direct targeting of miR-218 as a key player is promising in cancer therapy. LncRNAs and circRNAs are nonprotein coding transcripts that can regulate miR-218 expression in human cancers. Moreover, low expression level of miR-218 can be observed in human cancers such as brain, gastrointestinal and urological cancers that mediate poor prognosis and low survival rate.

Circular RNA hsa_circ_0003892 promotes the development of papillary thyroid carcinoma by regulating the miR-326/LASP1 axis

BACKGROUND

Thyroid cancer is the most common malignancy of the endocrine system. Circular RNA (circRNA) is recognized as a key regulator of tumorigenesis in papillary thyroid carcinoma (PTC). Here this work focused on the mechanism of circRNA_0003892 (circ_0003892) in PTC progression.

METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) was used to examine circ_0003892, microRNA-326 (miR-326) and LIM and SH3 protein 1 (LASP1) mRNA expression levels in PTC tissues and cell lines. Besides, cell counting kit-8 (CCK-8), EdU and transwell assays were conducted to detect the proliferative, migrative and invasive abilities of PTC cells, respectively. B The targeting relationships between miR-326 and circ_0003892 or LASP1 3'-UTR were verified by dual-luciferase reporter gene assay and RNA immunoprecipitation (RIP) assay.

RESULTS

Circ_0003892 expression was raised in PTC tissues and cells, which was significantly interrelated with larger tumor size and extrathyroidal extension in PTC sufferers. Overexpression of circ_0003892 significantly promoted the malignant biological behaviors of PTC cells. Additionally, miR-326 was a downstream target of circ_0003892, and miR-326 overexpression weakened the promoting effect of circ_0003892 overexpression on the malignant progression of PTC. MiR-326 specifically inhibited LASP1. Circ_0003892 positively regulated LASP1 expression by targeting miR-326.

CONCLUSION

Circ_0003892 up-regulates LASP1 expression and facilitates PTC progression via competitively binding to miR-326.

circPTPN22 attenuates immune microenvironment of pancreatic cancer via STAT3 acetylation

Accumulating research implicated that circular RNAs exhibited significant roles in cancer development. Nonetheless, the role regarding circPTPN22 in pancreatic cancer remains unclear. Expression of circPTPN22 in pancreatic cancer cell lines and normal cells was determined with quantitative real-time PCR (qRT-PCR). Cell counting kit-8 assay and colony formation assay were used to measure the proliferation of pancreatic cancer cells. RNA immunoprecipitation and Western blot were employed for investigation the binding between circPTPN22 and STAT3. circPTPN22 expression was highly upregulated in pancreatic cancer tissues and cell lines. Knockdown of circPTPN22 inhibited cell proliferation and attenuates pancreatic cancer immune microenvironment. Furthermore, STAT3 acetylation was involved in these effects. circPTPN22 promoted STAT3 acetylation via inhibiting STAT3/SIRT1 interaction. circPTPN22 attenuates pancreatic cancer immune microenvironment by promoting STAT3 acetylation via inhibiting STAT3/SIRT1 interaction.

Autophagy as a self-digestion signal in human cancers: Regulation by microRNAs in affecting carcinogenesis and therapy response

Autophagy is defined as a "self-digestion" signal, and it is a cell death mechanism its primary function is degrading toxic agents and aged organelles to ensure homeostasis in cells. The basic leve ls of autophagy are found in cells, and when its levels exceed to standard threshold, cell death induction is observed. Autophagy dysregulation in cancer has been well-documented, and regulation of this pathway by epigenetic factors, especially microRNAs (miRNAs), is interesting and noteworthy. miRNAs are considered short endogenous RNAs that do not encode functional proteins, and they are essential regulators of cell death pathways such as apoptosis, necroptosis, and autophagy. Accumulating data has revealed miRNA dysregulation (upregulation or downregulation) during tumor progression, and their therapeutic manipulation provides new insight into cancer therapy. miRNA/autophagy axis in human cancers has been investigated an exciting point is the dual function of both autophagy and miRNAs as oncogenic and onco-suppressor factors. The stimulation of pro-survival autophagy by miRNAs can increase the survival rate of tumor cells and mediates cancer metastasis via EMT inductionFurthermore, pro-death autophagy induction by miRNAs has a negative impact on the viability of tumor cells and decreases their survival rate. The miRNA/autophagy axis functions beyond regulating the growth and invasion of tumor cells, and they can also affect drug resistance and radio-resistance. These subjects are covered in the current review regarding the new updates provided by recent experiments.

Exosome-Delivered circSTAU2 Inhibits the Progression of Gastric Cancer by Targeting the miR-589/CAPZA1 Axis

Background

Circular RNAs (circRNAs) are endogenous noncoding RNAs that play vital roles in many biological processes, particularly in human cancer. Recent studies indicate that circRNAs play an important role in tumor progression through exosomes. However, the specific functions of gastric cancer-derived exosomes and the role of circSTAU2 in gastric cancer (GC) remain largely unknown.

Methods

Differentially expressed circRNAs in GC were identified by circRNA microarrays analysis and quantitative real-time polymerase chain reaction (qRT-PCR). The role of circSTAU2 in GC was verified by circSTAU2 knockdown and overexpression with functional assays both in vitro and in vivo. Fluorescence in situ hybridization (FISH), immunofluorescence, RNA immunoprecipitation (RIP), dual-luciferase reporter assay, qRT-PCR and Western blot were adopted to evaluate the expression and regulatory mechanism of MBNL1, circSTAU2, miR-589 and CAPZA1. Furthermore, the role of exosomes was demonstrated by transmission electron microscopy and nano-sight particle tracking analysis.

Results

CircSTAU2, mainly localized in the cytoplasm, was significantly downregulated in GC. CircSTAU2 overexpression inhibited GC cell proliferation, invasion and migration both in vitro and in vivo, while circSTAU2 knockdown had the inverse effect. CircSTAU2 could be wrapped in exosomes and delivered to recipient cells, and functioned as a sponge for miR-589 to relieve its inhibitory effect on CAPZA1, thus inhibiting GC progression. Furthermore, MBNL1 acted as the upstream RNA-binding protein of circSTAU2 and significantly influenced the circularization and expression of circSTAU2.

Conclusion

Exosome-delivered circSTAU2 may act as a tumor suppressor that restrains GC progression via miR-589/CAPZA1 axis, which demonstrates a potential therapeutic target for GC.

The Emerging Roles of circRNAs in Papillary Thyroid Carcinoma: Molecular Mechanisms and Biomarker Potential

Papillary thyroid carcinoma (PTC) is a common endocrine malignant tumor. The incidence of PTC has increased in the past decades and presents a younger trend. Accumulating evidence indicates that circular RNAs (circRNAs), featured with non-linear, closed-loop structures, play pivotal roles in tumorigenesis and regulate cell biological processes, such as proliferation, migration, and invasion, by acting as microRNA (miRNA) sponges. Additionally, due to their unique stability, circRNAs hold promising potential as diagnostic biomarkers and effective therapeutic targets for PTC treatment. In this review, we systematically arrange the expression level of circRNAs, related clinical characteristics, circRNA-miRNA-mRNA regulatory network, and molecular mechanisms. Furthermore, related signaling pathways and their potential ability of diagnostic biomarkers and therapeutic targets are discussed, which might provide a new strategy for PTC diagnosis, monitoring, and prognosis.

circRNA mannosidase alpha class 1A member 2 contributes to the proliferation and motility of papillary thyroid cancer cells through upregulating metadherin via absorbing microRNA-449a

Papillary thyroid carcinoma (PTC) is a common malignancy in endocrine system globally. Accumulating articles have found that circular RNAs (circRNAs) were dysregulated, and they were involved in PTC development. The aim of this project was to explore the function and associated mechanism of circRNA mannosidase alpha class 1A member 2 (circMAN1A2) in PTC progression. The expression of RNA was determined by real-time quantitative PCR. Cell proliferation ability was analyzed by colony formation assay and 5-ethynyl-2'-deoxyuridine assay. Cell migration and invasion were assessed by wound healing assay and transwell invasion assay, respectively. Protein levels were determined by Western blot assay. Dual-luciferase reporter assay and RNA immunoprecipitation assay were applied to confirm the interaction between microRNA-449a (miR-449a) and circMAN1A2 or metadherin (MTDH). Xenograft tumor model was utilized to explore the effect of circMAN1A2 silencing on tumor growth in vivo . CircMAN1A2 expression was elevated in PTC specimens and three PTC cell lines relative to adjacent normal specimens and Nthy-ori 3-1 cell line. CircMAN1A2 silencing inhibited the proliferation and motility of PTC cells. CircMAN1A2 acted as a molecular sponge of miR-449a, and circMAN1A2 knockdown suppressed PTC development partly through upregulating miR-449a. MiR-449a bound to the 3' untranslated region of MTDH, and miR-449a restrained PTC progression partly through down-regulating MTDH. CircMAN1A2 interference suppressed PTC progression in vivo . CircMAN1A2 contributed to the proliferation ability and motility of PTC cells through enhancing MTDH expression via sponging miR-449a.

Reveal the potential molecular mechanism of circRNA regulating immune-related mRNA through sponge miRNA in the occurrence and immune regulation of papillary thyroid cancer

BACKGROUND

Papillary thyroid cancer (PTC) is the most common endocrine malignant tumour. The purpose of this study was to explore the potential molecular mechanism of circRNA regulating immune-related mRNA through sponge miRNA in the occurrence and immune regulation of PTC.

METHODS

All data were downloaded from public databases, such as GEO, Immport and TCGA. Differentially expressed (DE) mRNAs (DEmRNAs), DEmiRNAs and DEcircRNAs were identified using metaMA and limma packages. Subsequently, immune-related DEmRNAs were screened, and circRNA-miRNA-mRNA (ceRNA) regulatory network was constructed. In addition, functional annotation, protein-protein interaction (PPI) network construction, immune cell infiltration analysis and Pearson correlation analysis were performed. Finally, qRT-PCR validation and cell experiments were also performed.

RESULTS

In total, 2962 DEmRNAs, 78 DEmiRNAs and 51 DEcircRNAs were obtained. Subsequently, 195 immune-related DEmRNAs were obtained based on Immport database. Cytokine-cytokine receptor interaction was the only signalling pathway obtained in KEGG analysis. Then, 8 hub immune-related DEmRNAs were identified based on PPI network and CytoHubba plug-in. Subsequently, ceRNA sub-network containing hub immune-related DEmRNAs was extracted from ceRNA regulatory network. In ceRNA sub-network, hsa_circ_0082182-hsa-miR-18b-5p-FGF1/PDGFC, hsa_circ_0016404-hsa-miR-1275-FGF1/CTSB/IL13RA1, hsa_circ_0070100-hsa-miR-27a-3p/hsa-miR-27b-3p-TGFBR3, hsa_circ_0060055/hsa_circ_0038718-hsa-miR-150-3p-CXCL14, hsa_circ_0030427/hsa_circ_0002917-hsa-miR-22-3p-BMP7 and hsa_circ_0030427/hsa_circ_0002917-hsa-miR-125a-5p-LIFR axes were identified. Moreover, FGF1, PDGFC, CTSB, IL13RA1, TGFBR3, CXCL14, BMP7, LIFR, hsa-miR-125a-5p, hsa-miR-1275, hsa-miR-150-3p, hsa-miR-18b-5p and hsa-miR-27b-3p were also found to have good diagnostic accuracy and may be potential novel diagnostic markers for PTC. XCell analysis showed that the levels of immune cell infiltration (including Tregs, HSC, DC and Monocytes) were significantly different between the PTC and the control groups. Knockdown of the expression of hsa_circ_0082182 significantly inhibits the activity, proliferation, migration and invasion of TPC-1 cells.

CONCLUSION

Several circRNA-miRNA-mRNA axes identified in this study may be related to the occurrence, progression and survival of PTC. This lays a theoretical foundation for further understanding the molecular mechanism of PTC, and also contributes to clinical management and research.

Circ_0002111 modulates the growth process of papillary thyroid carcinoma cells by targeting the miR-363-3p/HMGB1 axis

Previous studies have suggested that circular RNAs (circRNAs) are engaged in the progression of papillary thyroid carcinoma (PTC). However, the mechanism of circ_0002111 in PTC is still unclear. In this study, quantitative real-time PCR was carried out to measure the expressions of circ_0002111, microRNAs (miRNAs) and high-mobility group box 1 (HMGB1). Immunohistochemistry assay and western blot were applied for the determination of protein levels. The assays of 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide and thymidine analog 5-ethynyl-2'-deoxyuridine were deployed to assess PTC cell viability and proliferation, respectively. Besides, the capacities of cell apoptosis, invasion and angiogenesis were determined by flow cytometry, transwell and tube formation assays, respectively. Moreover, the interaction between miR-363-3p and circ_0002111 or HMGB1 was confirmed using a dual-luciferase reporter assay. Lastly, we established a xenograft model for the examination of the function of circ_0002111 in vivo. It was found that the expression of circ_0002111 was enhanced in PTC tissues and cells. Silencing circ_0002111 apparently retarded the viability, proliferation, invasion and tube formation, as well as expedited the apoptosis of PTC cells. Besides, circ_0002111 knockdown impeded the growth of the tumor in vivo. For mechanism analysis, circ_0002111 adjusted the expression of HMGB1 by sponge adsorption of miR-363-3p. Moreover, miR-363-3p inhibitor regained the influence of cellular malignant phenotype caused by circ_0002111 knockdown. Additionally, miR-363-3p overexpression impacted the cell functions by targeting HMGB1 in PTC. Thus, silencing circ_0002111 constrained the progression of PTC by the miR-363-3p/HMGB1 axis, which perhaps provided a novel idea of the therapeutic in PTC.

A Review and In Silico Analysis of Tissue and Exosomal Circular RNAs: Opportunities and Challenges in Thyroid Cancer

Simple Summary

Thyroid cancer is the most common endocrine neoplasm. Recently, knowledge of the molecular genetic changes of thyroid cancer has dramatically improved. Understanding the roles of these molecular changes in thyroid cancer tumorigenesis and progression is essential in developing a successful treatment strategy and improving disease outcomes. As a family of non-coding RNAs, circular RNAs (circRNAs) have been involved in several aspects of the physiological and pathological processes of the cells. The roles of circRNAs in cancer development and progress are evident. In the current review, we aimed to explore the clinical potential of circRNAs as potential diagnostic, prognostic, and therapeutic targets in thyroid cancer. Furthermore, screening the genome-wide circRNAs and performing functional enrichment analyses for all associated dysregulated circRNAs in thyroid cancer have been done. Given the unique advantages circRNAs have, such as superior stability, higher abundance, and presence in different body fluids, this family of non-coding RNAs could be promising diagnostic and prognostic biomarkers and potential therapeutic targets for thyroid cancer.

Abstract

Thyroid cancer (TC) is the most common endocrine tumor. The genetic and epigenetic molecular alterations of TC have become more evident in recent years. However, a deeper understanding of the roles these molecular changes play in TC tumorigenesis and progression is essential in developing a successful treatment strategy and improving patients’ prognoses. Circular RNAs (circRNAs), a family of non-coding RNAs, have been implicated in several aspects of carcinogenesis in multiple cancers, including TC. In the current review, we aimed to explore the clinical potential of circRNAs as putative diagnostic, prognostic, and therapeutic targets in TC. The current analyses, including genome-wide circRNA screening and functional enrichment for all deregulated circRNA expression signatures, show that circRNAs display atypical contributions, such as sponging for microRNAs, regulating transcription and translation processes, and decoying for proteins. Given their exceptional clinical advantages, such as higher stability, wider abundance, and occurrence in several body fluids, circRNAs are promising prognostic and theranostic biomarkers for TC.

lncKRT16P6 promotes tongue squamous cell carcinoma progression by sponging miR‑3180 and regulating GATAD2A expression

Tongue squamous cell carcinoma (TSCC) is characterized by a poor prognosis and its 5‑year overall survival rate has not improved significantly. However, the precise molecular mechanisms underlying TSCC remain largely unknown. Through RNA screening, the present study identified a novel long noncoding RNA (lncRNA), keratin 16 pseudogene 6 (lncKRT16P6), which was upregulated in TSCC tissues and cell lines and associated with TSCC tumor stage and differentiation grade. Inhibition of lncKRT16P6 expression reduced TSCC cell migration, invasion and proliferation. lncKRT16P6 sponged microRNA (miR)‑3180 and upregulated GATA zinc finger domain containing 2A (GATAD2A) expression. miR‑3180 inhibition reversed the lncKRT16P6 depletion‑induced attenuation of TSCC malignancy and GATAD2A depletion reversed the miR‑3180 silencing‑induced enhancement of TSCC malignancy. In summary, the present study revealed a potential competitive endogenous RNA (ceRNA) regulatory pathway in which lncKRT16P6 modulates GATAD2A expression by binding miR‑3180, ultimately promoting tumorigenesis and metastasis in TSCC. Therefore, lncKRT16P6 may be used as a prognostic biomarker and therapeutic target for clinical intervention in TSCC.

Biomarkers in Otorhinolaryngology

Biomarkers of otorhinolaryngologic diseases with higher insult over a person’s him/herself and overall health services are summarized in brief. In order to define, diagnose, treat and monitor any disease markers are needed. Otorhinolaryngology (ORL) is interested in special disease entities of the region besides otorhinolaryngologic involvements of the systemic diseases and unique forms of pathologies such as cholesteatoma, Meniere’s disease and otosclerosis. Neoplasia is another heading to deal with. In the following chapter, one will find an overview of molecules that have been used as a biomarker as well as the end points of the present research on the issue relevant with ORL. Day by day, new molecules are being named however, the pathways of action are rather the same. Readers will find the headings related to the most common diseases of the field, informing them about where to look for defining new strategies of understanding of each disease.

Identification of senescence-related subtypes, establishment of a prognosis model, and characterization of a tumor microenvironment infiltration in breast cancer

Breast cancer is a malignancy with the highest incidence and mortality in women worldwide. Senescence is a model of arrest in the cell cycle, which plays an important role in tumor progression, while the prognostic value of cellular senescence-related genes (SRGs) in evaluating immune infiltration and clinical outcomes of breast cancer needs further investigation. In the present study, we identified two distinct molecular subtypes according to the expression profiles of 278 SRGs. We further explored the dysregulated pathways between the two subtypes and constructed a microenvironmental landscape of breast cancer. Subsequently, we established a senescence-related scoring signature based on the expression of four SRGs in the training set (GSE21653) and validated its accuracy in two validation sets (GSE20685 and GSE25055). In the training set, patients in the high-risk group had a worse prognosis than patients in the low-risk group. Multivariate Cox regression analysis showed that risk score was an independent prognostic indicator. Receiver operating characteristic curve (ROC) analysis proved the predictive accuracy of the signature. The prognostic value of this signature was further confirmed in the validation sets. We also observed that a lower risk score was associated with a higher pathological response rate in patients with neoadjuvant chemotherapy. We next performed functional experiments to validate the results above. Our study demonstrated that these cellular senescence patterns effectively grouped patients at low or high risk of disease recurrence and revealed their potential roles in the tumor–immune–stromal microenvironment. These findings enhanced our understanding of the tumor immune microenvironment and provided new insights for improving the prognosis of breast cancer patients.

Circular RNA PVT1 promotes progression of thyroid cancer by competitively binding miR‑384

Plasmacytoma variant translocation 1 circular RNA (circPVT1) is involved in the initiation and development of several types of cancer. However, the underlying molecular role of circPVT1 in tumorigenesis of thyroid cancer remains to be elucidated. In the present study, relative expression of circPVT1 was markedly upregulated in thyroid cancer compared with adjacent normal tissue. circPVT1 expression was associated with clinical stage and lymph node metastasis. Furthermore, Cell Counting Kit-8, colony formation and Transwell chamber assays demonstrated that knockdown of circPVT1 decreased proliferation, migration and invasion of thyroid cancer cells in vitro. Moreover, circPVT1 directly interacted with microRNA (miR)-384, as shown by bioinformatics prediction and dual luciferase and RNA pull-down assay. miR-384 inhibition partially reversed the circPVT1 knockdown-mediated inhibitory effect on proliferation, migration and invasion of thyroid cancer cells. In summary, these findings demonstrated that circPVT1 may be a potential therapeutic target for thyroid cancer.

Function and Clinical Significance of Circular RNAs in Thyroid Cancer

Thyroid cancer (TC) is the leading cause and mortality of endocrine malignancies worldwide. Tumourigenesis involves multiple molecules including circular RNAs (circRNAs). circRNAs with covalently closed single-stranded structures have been identified as a type of regulatory RNA because of their high stability, abundance, and tissue/developmental stage-specific expression. Accumulating evidence has demonstrated that various circRNAs are aberrantly expressed in thyroid tissues, cells, exosomes, and body fluids in patients with TC. CircRNAs have been identified as either oncogenic or tumour suppressor roles in regulating tumourigenesis, tumour metabolism, metastasis, ferroptosis, and chemoradiation resistance in TC. Importantly, circRNAs exert pivotal effects on TC through various mechanisms, including acting as miRNA sponges or decoys, interacting with RNA-binding proteins, and translating functional peptides. Recent studies have suggested that many different circRNAs are associated with certain clinicopathological features, implying that the altered expression of circRNAs may be characteristic of TC. The purpose of this review is to provide an overview of recent advances on the dysregulation, functions, molecular mechanisms and potential clinical applications of circRNAs in TC. This review also aimes to improve our understanding of the functions of circRNAs in the initiation and progression of cancer, and to discuss the future perspectives on strategies targeting circRNAs in TC.

Noncoding RNAs in Thyroid-Follicular-Cell-Derived Carcinomas

Simple Summary

Thyroid tumors represent the most common neoplastic pathology of the endocrine system. Mutations occurring in oncogenes and tumor suppressor genes are responsible for thyroid carcinogenesis; however, the complete mutational landscape characterizing these neoplasias has not been completely unveiled. It has been established that only the 2% of the human genome codes for proteins, suggesting that the vast majority of the genome has regulatory capabilities, which, if altered, could account for the onset of cancer. Hence, many scientific efforts are currently focused on the characterization of the heterogeneous class of noncoding RNAs, which represent an abundant part of the transcribed noncoding genome. In this review, we mainly focus on the involvement of microRNAs, long noncoding RNAs, and pseudogenes in thyroid cancer. The determination of the diagnosis, prognosis, and treatment of thyroid cancers based on the evaluation of the noncoding RNA network could allow the implementation of a more personalized approach to fighting these pathologies.

Abstract

Among the thyroid neoplasias originating from follicular cells, we can include well-differentiated carcinomas, papillary (PTC) and follicular (FTC) thyroid carcinomas, and the undifferentiated anaplastic (ATC) carcinomas. Several mutations in oncogenes and tumor suppressor genes have already been observed in these malignancies; however, we are still far from the comprehension of their full regulation-altered landscape. Even if only 2% of the human genome has the ability to code for proteins, most of the noncoding genome is transcribed, constituting the heterogeneous class of noncoding RNAs (ncRNAs), whose alterations are associated with the development of several human diseases, including cancer. Hence, many scientific efforts are currently focused on the elucidation of their biological role. In this review, we analyze the scientific literature regarding the involvement of microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and pseudogenes in FTC, PTC, and ATC. Recent findings emphasized the role of lncRNAs in all steps of cancer progression. In particular, lncRNAs may control progression steps by regulating the expression of genes and miRNAs involved in cell proliferation, apoptosis, epithelial–mesenchymal transition, and metastatization. In conclusion, the determination of the diagnosis, prognosis, and treatment of cancer based on the evaluation of the ncRNA network could allow the implementation of a more personalized approach to fighting thyroid tumors.

Circ_0051079 silencing inhibits the malignant phenotypes of osteosarcoma cells by the TRIM66/Wnt/β-catenin pathway in a miR-625-5p-dependent manner

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Circ_0051079 was significantly increased in OS tissues and cells.

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Circ_0051079 knockdown inhibited OS cell malignant progression.

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Circ_0051079 regulated TRIM66 expression through miR-625-5p.

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Circ_0051079 mediated the Wnt/β-catenin pathway by regulating TRIM66.

Background

Methods

Results

Conclusion

Differential gene expression profile of multinodular goiter

Introduction

The goiter, a neglected heterogeneous molecular disease, remains a major indication for thyroidectomies in its endemic regions.

Objectives

This study analyzed differential gene expression in surgical specimens diagnosed with multi nodular and compared the data to that of thyroid tissue without multinodular goiter from patients undergoing thyroidectomy in Manaus-AM, Brazil using RNA-seq technology.

Methodology

The transcriptome information of the surgical specimen fragments with and without multinodular goiter was accessed by Illumina HiSeq 2000 New Generation Sequencing (NGS) using the RNA-seq NEBNext^® Ultra^™ RNA Library Prep Kit for Illumina^®—#E7530L protocol and differential gene expression analysis.

Results

Differences were found between the gene expression profiles of the diseased tissues and those of the healthy control tissues; at least 70 genes were differentially expressed. The HOTS gene was expressed only in multinodular goiter tissues (p < 0.05).

Conclusion

These results demonstrate that the gene expression profile of multinodular goiter is pro-tumoral and that HOTS can play a central role in multinodular goiter development.

Hsa_circ_0058129 regulates papillary thyroid cancer development via miR‐873‐5p/follistatin‐like 1 axis

Background

Papillary thyroid cancer (PTC) is an endocrine malignancy with a high incidence. Circular RNAs (circRNAs) participate in regulating PTC. Here, we analyzed the role of hsa_circ_0058129 (circ_0058129) in PTC.

Methods

The expression of circ_0058129, fibronectin 1 (FN1) mRNA, microRNA‐873‐5p (miR‐873‐5p), and follistatin‐like 1 (FSTL1) was detected by qRT‐PCR and western blot. Cell proliferation was analyzed by CCK‐8, EdU, and flow cytometry analysis assays. Cell migration and invasion were evaluated by Transwell assay. The targeting relationship of miR‐873‐5p and circ_0058129 or FSTL1 was identified through dual‐luciferase reporter assay, RIP assay, and RNA pull‐down assay. Xenograft mouse model assay was implemented to determine the effect of circ_0058129 on tumor formation in vivo.

Results

The circ_0058129 and FSTL1 abundances were increased, while the miR‐873‐5p content was decreased in PTC tissues and cells compared with control groups. Circ_0058129 shortage inhibited PTC cell proliferation, migration, and invasion. Moreover, miR‐873‐5p repressed PTC cell malignancy by binding to FSTL1. Circ_0058129 targeted miR‐873‐5p to regulate FSTL1.

Conclusion

Circ_0058129 expedited PTC progression through the miR‐873‐5p/FSTL1 pathway.

Evaluation of genetic variants in nucleosome remodeling and deacetylase (NuRD) complex subunits encoding genes and gastric cancer susceptibility

Epigenetic complex NuRD (nucleosome remodeling and deacetylase) engages in a range of basic cellular processes, including chromatin modification. Changes in the activity of NuRD complex can influence gastric cancer progression. Multivariate logistic regression analyses were used to estimate the association between single-nucleotide polymorphisms (SNPs) and gastric cancer risk. Expression quantitative trait loci (eQTL) analysis was used to analyze the relationship between the genotypes and gene expression levels using data from the genotype tissue expression project (GTEx). Gene expression was calculated using databases from The Cancer Genome Atlas (TCGA) and The Gene Expression Omnibus (GEO). Kaplan-Meier plotter was used to evaluate the association between gene expression and survival. SNP rs11064275 T allele in CHD4, rs892022 A allele and rs2033481 A allele in GATAD2A were found to contribute to the decreased risk of gastric cancer. The increase in the number of favorable alleles of these three SNPs was associated with a lower risk of gastric cancer. rs2033481 and rs892022 were substantially correlated with GATAD2A mRNA expression levels. Meanwhile, we detected that the CHD4 and GATAD2A mRNA expression was increased in gastric cancer tissues compared with the adjacent normal tissues. Furthermore, we found that patients with higher CHD4 or GATAD2A mRNA expression level had more advantageous overall survival. Our findings indicated that genetic variants in NuRD complex subunits encoding genes may be promising predictors of gastric cancer risk.

Circ_0041732 regulates tumor properties of triple-negative breast cancer cells by the miR-149-5p/FGF5 pathway

BACKGROUND

Triple-negative breast cancer (TNBC) is a subtype of breast cancers with a high recurrence and mortality. The important factors promoting the TNBC process have not been fully identified. In this research, the role of a TNBC-related circular RNA (circRNA), circ_0041732, was revealed in TNBC cell tumor properties.

METHODS

The expression levels of circ_0041732, microRNA-149-5p (miR-149-5p) and fibroblast growth factor 5 (FGF5) were detected by quantitative real-time polymerase chain reaction. The protein expression was determined by Western blot analysis or immunohistochemistry assay. Cell proliferation was detected by cell counting kit-8 and cell colony formation assays. Cell apoptosis was analyzed by flow cytometry and caspase-3 activity assays. Cell migration and invasion were evaluated by wound-healing and transwell invasion assays. Cell angiogenic capacity was investigated by a tube formation assay. The targeting relationship between miR-149-5p and circ_0041732 or FGF5 was identified by dual-luciferase reporter and RNA immunoprecipitation assays. The impacts of circ_0041732 knockdown on tumor formation were determined by an in vivo assay.

RESULTS

Circ_0041732 and FGF5 expression were significantly upregulated, whereas miR-149-5p was downregulated in TNBC tissues and cells compared with normal breast tissues and cells, respectively. Circ_0041732 silencing inhibited TNBC cell proliferation, migration, invasion, and tube formation, but induced apoptosis. Additionally, circ_0041732 regulated TNBC cell tumor properties by binding to miR-149-5p. MiR-149-5p also modulated TNBC cell tumor properties by targeting FGF5. Furthermore, circ_0041732 knockdown hindered tumor formation in vivo.

CONCLUSION

Circ_0041732 silencing suppressed TNBC cell tumor properties by decreasing FGF5 expression through miR-149-5p. This finding demonstrated that circ_0041732 had the potential as a therapeutic target for TNBC.

Circular RNAs and thyroid cancer: closed molecules, open possibilities

Thyroid neoplasms requiring differential diagnosis between thyroid cancer and benign tumors can be detected in more than half of the healthy population. A generally accepted method that allows assessing the risk of malignant potential and determining the indications for surgical treatment of thyroid tumor is a fine-needle aspiration biopsy followed by a cytological examination. Nevertheless, in patients with indeterminate categories of cytological conclusions according to Bethesda system, the positive predictive value of the cytology result is significantly lower than desired and often leads to unjustified surgical treatment. In this regard, the search for alternative diagnostic solutions continues. Circular RNAs are a group of non-coding RNAs distinguished by a closed structure formed by covalent bonding of the nucleotide chain ends. Recent studies allow us to conclude that many different circular RNAs are involved in processes mediating oncogenesis in the thyroid gland, and their altered expression in tissue, blood, and exosomes of plasma may be a characteristic sign of thyroid cancer and certain clinicopathological features of its course. The purpose of this review is to analyze the accumulated data on the association of various circular RNAs with thyroid cancer and to discuss possible ways to improve the diagnosis and treatment of the disease based on the assessment of the expression of these molecules.

Knockdown of long noncoding RNA HUMT inhibits the proliferation and metastasis by regulating miR-455-5p/LRP4 axis in hepatocellular carcinoma

The present study aimed at investigating the effects and mechanism of long noncoding RNA highly upregulated in metastatic triple-negative breast cancer lymph node (lncRNA HUMT) in hepatocellular carcinoma (HCC). Quantitative real-time polymerase chain reaction was used to assess the expression of HUMT, microRNA (miR)-455-5p, and low-density lipoprotein receptor-related protein 4 (LRP4) in HCC tissues. Colony forming and 5-ethynyl-2′-deoxyuridine assays were performed to assess cell proliferation. Transwell assay was performed to measure cell migration and invasion. Cell cycle distribution was assessed using flow cytometry. The protein expression of LRP4, proliferating cell nuclear antigen (PCNA), matrix metallopeptidase 2 (MMP-2), and MMP-9 was detected using western blot. Luciferase reporter assay and RNA immunoprecipitation assay was used to confirm the target association between miR-455-5p and HUMT or LRP4. In our study, the level of HUMT was enhanced in HCC tissues and cells. Cell proliferation, invasion, and migration in HCC cells were repressed by knockdown of HUMT, and knockdown of HUMT arrested cells in G1 phase and decreased the levels of PCNA, MMP-2, and MMP-9. MiR-455-5p was a target of HUMT. Lowexpression of miR-455-5p reversed the inhibitive influence on HCC cells induced by of HUMT silencing. LRP4 was a target of miR-455-5p and was negatively regulated by miR-455-5p. In addition, LRP4 expression was positively modified by HUMT, and LRP4 inhibited the inhibitory effects on HCC cells induced by HUMT silencing. In conclusion, HCC cell proliferation, invasion, and migration were restrained by knockdown of HUMT, which was related to the miR-455-5p/LRP4 axis.

Emerging role of competing endogenous RNA and associated noncoding RNAs in thyroid cancer

Cancer of the thyroid is the most common endocrine malignancy. While treatment options are limited for individuals with medullary or anaplastic thyroid cancer, understanding the underlying mechanisms is vital to developing a successful thyroid cancer treatment strategy due to the tumor's multistep carcinogenesis. Non-coding RNAs (ncRNAs) have been associated with thyroid cancer progression in several recent studies; however, the role of regulatory interactions among different types of ncRNAs in thyroid cancer remains unclear. Recently, competing endogenous RNA (ceRNA) has been discovered as a mechanism demonstrating regulatory interactions among non-coding RNAs, including pseudogenes, long non-coding RNAs (lnRNAs), circular RNAs (circRNAs), and microRNAs (miRNAs). It has been concluded from the literature that numerous ceRNA networks are deregulated during the development, invasion, and metastasis of thyroid cancer, as well as in epithelial-mesenchymal transition (EMT) and drug resistance. Further understanding of these deregulations is important to develop diagnostic procedures for early detection of thyroid cancer and promising therapeutic options for effective treatment. The purpose of this review is to highlight the emerging roles of some newly found ceRNA members in thyroid cancer and outline the current body of knowledge regarding ceRNA, lncRNA, pseudogenes, and miRNAs.

lncRNA ZNF674-AS1 inhibits the migration, invasion and epithelial-mesenchymal transition of thyroid cancer cells by modulating the miR-181a/SOCS4 axis

Thyroid cancer (TC) is a very common endocrine cancer worldwide. Further understanding and revealing the molecular mechanism underlying thyroid cancer are indispensable for the development of effective diagnosis and treatments. Long non-coding RNAs (lncRNAs), a series of non-coding RNAs with a length of >200 nts, have been regarded as crucial regulators of many cancers playing a tumor suppressive or oncogenic role, depending on circumstances. lncRNA ZNF674-AS1 was reported to be abnormally expressed in TC, but the exact mechanism remains unclear. This study aims to probe the mechanism and roles of ZNF674-AS1 in TC. The expression patterns of RNAs and proteins were determined via qRT-PCR and western blotting, respectively. Cell proliferation, migration and invasion were detected using MTT and Transwell assays. ZNF674-AS1 and SOCS4 expression were remarkably reduced while miR-181a was upregulated in TC tissues and cells. Enforced expression of ZNF674-AS1 inhibited proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) in vitro and reduced tumour growth in vivo. Mechanistic assays verified that ZNF674-AS1 directly interacted with miR-181a to increase SOCS4 expression. In addition, miR-181a overexpression aggravated proliferation, metastasis and EMT by inhibiting SOCS4. Interestingly, inhibition of miR-181a diminished the promoting effects of ZNF674-AS1 silencing on the malignant behaviours of TC cells. These data illustrated that ZNF674-AS1 alleviated TC progression by modulating the miR-181a/SOCS4 axis (graphical abstract), further suggesting that ZNF674-AS1 might be used as a therapheutic target in TC treatment.

Circular RNA coiled-coil domain containing 66 regulates malignant development of papillary thyroid carcinoma by upregulating La ribonucleoprotein 1 via the sponge effect on miR-129-5p

Circular RNAs (circRNAs) play vital roles in the development and progression of various diseases. CircRNA coiled-coil domain containing 66 (circ-CCDC66) has been reported to be involved in several cancers, but its biological function and underlying mechanism in papillary thyroid carcinoma (PTC) remain unclear. We detected the relative expression level of circ-CCDC66 in PTC specimens and cell lines using real-time reverse transcription PCR. In addition, EdU assay, transwell assay, and xenograft analysis were performed to measure the effect of circ-CCDC66 on the proliferative, migratory, and invasive capacities of PTC cells. We also investigated the potential mechanism of circ-CCDC66 by bioinformatics analysis, RNA immunoprecipitation, and dual-luciferase reporter assay. We observed that circ-CCDC66 expression was upregulated in PTC specimens and cell lines and was correlated with poor clinical characteristics of PTC patients. Moreover, in vitro experiments demonstrated that knockdown of circ-CCDC66 markedly suppressed the proliferative, migratory, and invasive capacities of PTC cells. Mechanistically, miR-129-5p was a target gene of circ-CCDC66 and was downregulated in PTC tissues. LARP1, a downstream target of miR-129-5p, was upregulated in PTC tissues. In addition, we confirmed that inhibition of circ-CCDC66 could repress xenograft tumor growth. Circ-CCDC66 promoted PTC proliferation, migration, invasion, and tumor growth by sponging miR-129-5p and promoting LARP1 expression.

The mmu_circRNA_37492/hsa_circ_0012138 function as potential ceRNA to attenuate obstructive renal fibrosis

Circular RNAs (circRNAs) are involved in the pathogenesis of certain renal diseases, however, the function and mechanism of them in renal fibrosis remains largely unknown. In the present study, RNA expression data in unilateral ureteral obstruction (UUO) kidneys was obtained from our previous circRNA Microarray and public Gene Expression Omnibus datasets to construct a ceRNA network. The effects of target circRNA as long as the homologous human circRNA on renal fibrosis was examined in vitro and in vivo. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis was further performed among genes regulated by the human circRNA. We found that circRNA_37492, showing well connection degree in the ceRNA network, was abundant expression and high sequence conservation. We observed that the expression of circRNA_37492 was induced by the TGF-β1 or UUO in BUMPT cells and C57BL/6 mice, respectively. In vitro, cytoplasmic circRNA_37492 inhibited type I, III collagen and fibronectin deposition by sponging miR-7682-3p and then upregulated its downstream target Fgb. In vivo, overexpression of circRNA_37492 attenuated fibrotic lesions in the kidneys of UUO mice via targeting miR-7682-3p/Fgb axis. Furthermore, hsa_circ_0012138, homologous with circRNA_37492, may potentially target miR-651-5p/FGB axis in human renal fibrosis. Not only that, GO and KEGG enrichment revealed that hsa_circ_0012138-regulated genes were previously demonstrated to related to the fibrosis. In conclusion, we for the first time demonstrated that circRNA_37492 attenuated renal fibrosis via targeting miR-7682-3p/Fgb axis, and the homologous hsa_circRNA_0012138 was speculated as a possible ceRNA to regulate multiple gene expressions and involve in human renal fibrosis, suggesting that circRNA_37492/hsa_circ_0012138 may serve as potent therapy target for obstructive renal fibrosis disease.

Downregulation of sperm-associated antigen 5 inhibits melanoma progression by regulating forkhead box protein M1/A disintegrin and metalloproteinase 17/NOTCH1 signaling

Sperm-associated antigen 5 (SPAG5) has been identified as a driver in several type of cancers. In this study, we aimed to reveal the role of SPAG5 in melanoma and clarify whether FOXM1 (forkhead box protein M1) /ADAM17 (A disintegrin and metalloproteinase 17) /NOTCH1 signaling was involved. The expression of SPAG5 in malignant melanoma (MM) tissues and matched normal tissues was detected using qRT-PCR, immunohistochemistry and Western blotting. Cell viability was tested using CCK-8 (Cell Count Kit-8), colony formation and EdU staining. Cell migration and epithelial to mesenchymal transition (EMT) were measured using transwell chambers and immunofluorescent staining. Cell cycle distribution and tumorigenesis were assessed by flow cytometry and in vivo tumor-bearing experiments, respectively. The results demonstrated that the expression of SPAG5 was increased in MM tissues and cells. Downregulation of SPAG5 inhibited cell viability, migration, invasion and EMT, and induced a G1-phase arrest. In addition, downregulation of SPAG5 decreased the expression of FOXM1, thereafter inhibiting the expression of ADAM17, NOTCH1 and HES1. Furthermore, deletion of SPAG5 expression decreased the tumorigenesis of MM A375 cells. In conclusion, this study demonstrated that SPAG5 was overexpressed in MM. Downregulation of SPAG5 repressed MM cell growth and EMT, which might be induced by inactivation of the FOXM1/ADAM17/NOTCH1 signaling.