A potential biomarker hsa-miR-200a-5p distinguishing between benign thyroid tumors with papillary hyperplasia and papillary thyroid carcinoma

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

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

A novel prognostic signature for clear cell renal cell carcinoma constructed using necroptosis-related miRNAs

Background

This work aims to analyze the relationship between necroptosis-related microRNAs (miRNAs) and the prognosis of clear cell renal cell carcinoma (ccRCC).

Methods

The miRNAs expression profiles of ccRCC and normal renal tissues from The Cancer Genome Atlas (TCGA) database were used to construct a matrix of the 13 necroptosis-related miRNAs. Cox regression analysis was used to construct a signature to predict the overall survival of ccRCC patients. The genes targeted by the necroptosis-related miRNAs in the prognostic signature were predicted using miRNA databases. Gene Ontology (Go) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were used to investigate the genes targeted by the necroptosis-related miRNAs. The expression levels of selected miRNAs in 15 paired samples (of ccRCC tissues and adjacent normal renal tissues) were investigated using reverse transcriptase quantitative polymerase chain reaction (RT-qPCR).

Results

Six necroptosis-related miRNAs were found to differentially expressed between ccRCC and normal renal tissues. A prognostic signature consisting of miR-223-3p, miR-200a-5p, and miR-500a-3p was constructed using Cox regression analysis and risk scores were calculated. Multivariate Cox regression analysis showed that the hazard ratio was 2.0315 (1.2627–3.2685, P = 0.0035), indicating that the risk score of the signature was an independent risk factor. The receiver operating characteristic (ROC) curve showed that the signature has a favorable predictive capacity and the Kaplan-Meier survival analysis indicated that ccRCC patients with higher risk scores had worse prognoses (P < 0.001). The results of the RT-qPCR verified that all three miRNAs used in the signature were differentially expressed between ccRCC and normal tissues (P < 0.05).

Conclusion

The three necroptosis-related-miRNAs used in this study could be a valuable signature for the prognosis of ccRCC patients. Necroptosis-related miRNAs should be further explored as prognostic indicators for ccRCC.

A Novel-Defined Necroptosis-Related miRNA Signature for Forecasting the Prognosis of Low-Grade Glioma

Background

Increasing evidence has shown that necroptosis has enormous significance in the generation and deterioration of cancer, and miRNA molecular markers involved in necroptosis in low-grade gliomas (LGGs) have not been thoroughly reported.

Methods

Using the miRNA data of 512 samples from The Cancer Genome Atlas (TCGA), 689 miRNAs from LGG samples were split into high immunity score and low immunity score groups for analysis. The differential miRNAs related to necroptosis were analyzed by univariate Cox regression analysis. On the basis of the outcome of univariate Cox regression analysis, miRNAs with significant differences were selected to construct a multivariate Cox regression model and calculate the risk score. Then, we evaluated whether the risk score could be used as an unaided prognostic factor.

Results

Overall, six differential miRNAs were identified (hsa-miR-148a-3p, hsa-miR-141-3p, hsa-miR-223-3p, hsa-miR-7-5p, hsa-miR-500a-3p, and hsa-miR-200a-5p). Univariate and multivariate Cox regression analyses were performed, and the c index was 0.71. Then, by mixing the risk score with clinicopathological factors, univariate Cox regression (HR: 2.7146, 95% CI: 1.8402−4.0044, P < 0.0001) and multivariate Cox regression analyses (HR: 2.3280, 95% CI: 1.5692−3.4536, P < 0.001) were performed. The data suggested that the risk score is an unaided prognostic indicator, which is markedly related with the overall survival time of LGG sufferers. Thus, a lower risk score is correlated with better prediction of LGG.

Conclusion

In order to achieve the ultimate goal of improving the living conditions of patients, we established prognostic risk model using 6 miRNAs related to necroptosis, which has the ability to predict the prognosis of LGG. It is possible to further enrich the therapeutic targets for LGG and provide clinical guidance for the treatment of LGG in the future.

MicroRNAs in Papillary Thyroid Cancer: What Is New in Diagnosis and Treatment

Introduction

Papillary thyroid cancer (PTC) accounts for up to 80% of thyroid malignancies. New diagnostic and therapeutic options are suggested including innovative molecular methods. MicroRNAs (miRNAs) are nonprotein coding single-stranded RNAs that regulate many cell processes. The aim of the present study is to review the deregulated miRNAs associated with PTCs.

Methods

A bibliographic research was conducted, resulting in 272 articles referred to miRNAs and PTC. Regarding our exclusion criteria, 183 articles were finally included in our review.

Results

A remarkably large number of miRNAs have been found to be deregulated during PTC manifestation in the literature. The deregulated miRNAs are detected in tissue samples, serum/plasma, and FNA samples of patients with PTC. These miRNAs are related to several molecular pathways, involving genes and proteins responsible for important biological processes. MiRNA deregulation is associated with tumor aggressiveness, including larger tumor size, multifocality, extrathyroidal extension, lymphovascular invasion, lymph node and distant metastasis, and advanced tumor node metastasis stage.

Conclusion

MiRNAs are proposed as new diagnostic and therapeutic tools regarding PTC. They could be essential biomarkers for PTC diagnosis applied in serum and FNA samples, while their contribution to prognosis is of great importance.

Circ_0058124 Aggravates the Progression of Papillary Thyroid Carcinoma by Activating LMO4 Expression via Targeting miR-370-3p

Background

Thyroid cancer is the most common malignant tumor in the endocrine system. Papillary thyroid carcinoma (PTC) accounts for the vast majority of cases in this cancer. Recently, the vital role of circular RNA (circRNA) has been acknowledged in various cancers, and this study aimed to investigate the role of circ_0058124 and related mechanism of its action in PTC.

Materials and Methods

The expression of circ_0058124, miR-370-3p and LIM domain only (LMO4) was detected by qRT-PCR in tissue samples (PTC tissues or normal tissues, n=20) and cell lines (non-cancer cell line, Nthy-ori 3–1, and PTC cell lines, IHH-4 and TPC-1). For functional analysis, cell proliferation was investigated using CCK-8 assay and colony formation assay. Cell migration and invasion were determined using transwell assay, and cell migration was also assessed by wound healing assay. Cell apoptosis was monitored by flow cytometry assay. For mechanism analysis, the interaction between miR-370-3p and circ_0058124 or LMO4 predicted by the bioinformatics analysis was validated by dual-luciferase reporter assay or RIP assay. The effect of circ_0058124 on tumor growth in vivo was identified by establishing the Xenograft model.

Results

The expression of circ_0058124 was enhanced in PTC tissues and cells. Circ_0058124 knockdown inhibited viability, colony formation, migration and invasion and promoted apoptosis of PTC cells. Besides, circ_0058124 knockdown also blocked tumor growth in vivo. miR-370-3p was a target of circ_0058124, and circ_0058124 regulated the expression of LMO4, a target of miR-370-3p, by targeting miR-370-3p. Rescue experiments presented that miR-370-3p inhibition reversed the inhibitory effects of circ_0058124 knockdown on PTC development, and LMO4 overexpression reversed the effect of miR-370-3p restoration on PTC development.

Conclusion

Circ_0058124 promoted the development of PTC by mediating the miR-370-3p/LMO4 axis, and circ_0058124, functioned as an oncogene in PTC, might be used as a promising biomarker for PTC diagnosis and treatment.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Downregulation of miR‑193a‑3p via targeting cyclin D1 in thyroid cancer

Thyroid cancer (TC) is a frequently occurring malignant tumor with a rising steadily incidence. microRNA (miRNA/miR)‑193a‑3p is an miRNA that is associated with tumors, playing a crucial role in the genesis and progression of various cancers. However, the expression levels of miR‑193a‑3p and its molecular mechanisms in TC remain to be elucidated. The present study aimed to probe the expression of miR‑193a‑3p and its clinical significance in TC, including its underlying molecular mechanisms. Microarray and RNA sequencing data gathered from three major databases, specifically Gene Expression Omnibus (GEO), ArrayExpress and The Cancer Genome Atlas (TCGA) databases, and the relevant data from the literature were used to examine miR‑193a‑3p expression. Meta‑analysis was also conducted to evaluate the association between clinicopathological parameters and miR‑193a‑3p in 510 TC and 59 normal samples from the TCGA database. miRWalk 3.0, and the TCGA and GEO databases were used to predict the candidate target genes of miR‑193a‑3p. Gene Ontology, Kyoto Encyclopedia of Genes and Genomes and protein‑protein interaction network enrichment analyses were conducted by using the predicted candidate target genes to investigate the underlying carcinogenic mechanisms. A dual luciferase assay was performed to validate the targeting regulatory association between the most important hub gene cyclin D1 (CCND1) and miR‑193a‑3p. miR‑193a‑3p expression was considerably downregulated in TC compared with in the non‑cancer controls (P<0.001). The area under the curve of the summary receiver operating characteristic was 0.80. Downregulation of miR‑193a‑3p was also significantly associated with age, sex and metastasis (P=0.020, 0.044 and 0.048, respectively). Bioinformatics analysis indicated that a low miR‑193a‑3p expression may augment CCND1 expression to affect the biological processes of TC. In addition, CCND1, as a straightforward target, was validated through a dual luciferase assay. miR‑193a‑3p and CCND1 may serve as prognostic biomarkers of TC. Finally, miR‑193a‑3p may possess a crucial role in the genesis and progression of TC by altering the CCND1 expression.

Genome-Wide Identification and Analysis of Enhancer-Regulated microRNAs Across 31 Human Cancers

Enhancers are cis-regulatory DNA elements that positively regulate the transcription of target genes in a tissue-specific manner, and dysregulation of target genes could lead to various diseases, such as cancer. Recent studies have shown that enhancers can regulate microRNAs (miRNAs) and participate in their biological synthesis. However, the network of enhancer-regulated miRNAs across multiple cancers is still unclear. Here, a total of 2,418 proximal enhancer-miRNA interactions and 1,280 distal enhancer-miRNA interactions were identified through the integration of genomic distance, co-expression, and 3D genome data in 31 cancers. The results showed that both proximal and distal interactions exhibited a significant cancer type-specific feature trend at the tissue level rather than at the single-cell level, and there was a noteworthy positive correlation between the expression of the miRNA and the number of enhancers regulating the same miRNA in most cancers. Furthermore, we found that there was a high correlation between the formation of enhancer-miRNA pairs and the expression of enhancer RNAs (eRNAs) whether in distal or proximal regulation. The characteristics analysis showed that miRes (enhancers that regulated miRNAs) and non-miRes presented significant differences in sequence conservation, guanine-cytosine (GC) content, and histone modification signatures. Notably, GC content, H3K4me1, and H3K36me3 were present differently between distal and proximal regulation, suggesting that they might participate in chromosome looping of enhancer-miRNA interactions. Finally, we introduced a case study, enhancer: chr1:1186391-1186507 ∼ miR-200a was highly relevant to the survival of thyroid cancer patients and a cis-eQTL SNP on the enhancer affected the expression of the TNFRSF18 gene as a tumor suppressor.

Identification of miR-200a-5p targeting the peptide transporter TAP1 and its association with the clinical outcome of melanoma patients

Tumor escape is often associated with abnormalities in the surface expression of the human leukocyte antigen class I (HLA-I) antigens thereby limiting CD8+ cytotoxic T cell responses. This impaired HLA-I surface expression can be mediated by deficient expression of components of the antigen processing and presentation machinery (APM) due to epigenetic, transcriptional and/or post-transcriptional processes. Since a discordant mRNA and protein expression pattern of APM components including the peptide transporter associated with antigen processing 1 (TAP1) has been frequently described in tumors of distinct origin, a post-transcriptional control of APM components caused by microRNAs (miR) was suggested. Using an in silico approach, miR-200a-5p has been identified as a candidate miR binding to the 3' untranslated region (UTR) of TAP1. Luciferase reporter assays demonstrated a specific binding of miR-200a-5p to the TAP1 3'-UTR. Furthermore, the miR-200a-5p expression is inversely correlated with the TAP1 protein expression in HEK293T cells and in a panel of melanoma cell lines as well as in primary melanoma lesions. High levels of miR-200a-5p expression were associated with a shorter overall survival of melanoma patients. Overexpression of miR-200a-5p reduced TAP1 levels, which was accompanied by a decreased HLA-I surface expression and an enhanced NK cell sensitivity of melanoma cells. These data show for the first time a miR-mediated control of the peptide transporter subunit TAP1 in melanoma thereby leading to a reduced HLA-I surface expression accompanied by an altered immune recognition and reduced patients' survival.

Abbreviations

Ab: antibody; ACTB: β-actin; APM: antigen processing and presentation machinery; ATCC: American tissue culture collection; β2-m: β2-microglobulin; BSA: bovine serum albumin; CTL: cytotoxic T lymphocyte; FCS: fetal calf serum; FFL: firefly luciferase; FFPE: formalin-fixed paraffin-embedded; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; HC: heavy chain; HLA: human leukocyte antigen; HLA-I: HLA class I; HRP: horseradish peroxidase; IFN: interferon; im-miR: immune modulatory miRNA; LMP: low molecular weight protein; luc: luciferase; MFI: mean fluorescence intensity; MHC: major histocompatibility complex; miR: microRNA; NC: negative control; NK: natural killer; NSCLC: non-small cell lung carcinoma; OS: overall survival; PBMC: peripheral blood mononuclear cells; RBP: RNA-binding proteins; RL: Renilla; RLU: relative light units; TAP: transporter associated with antigen processing; tpn: tapasin; UTR: untranslated region.