MiR-618 inhibits anaplastic thyroid cancer by repressing XIAP in one ATC cell line

Ubiquitin-modifying enzymes in thyroid cancer：Mechanisms and functions

Thyroid cancer is the most common malignant tumor of the endocrine system, and evidence suggests that post-translational modifications (PTMs) and epigenetic alterations play an important role in its development. Recently, there has been increasing evidence linking dysregulation of ubiquitinating enzymes and deubiquitinases with thyroid cancer. This review aims to summarize our current understanding of the role of ubiquitination-modifying enzymes in thyroid cancer, including their regulation of oncogenic pathways and oncogenic proteins. The role of ubiquitination-modifying enzymes in thyroid cancer development and progression requires further study, which will provide new insights into thyroid cancer prevention, treatment and the development of novel agents.

Correlation between the miR-618 rs2682818 C>A polymorphism and venous malformation susceptibility

Venous malformations are the most common congenital vascular malformations, and the incidence rate is high. Previous studies have confirmed that a variety of polymorphisms within the miRNA functional region are associated with tumor susceptibility. We examined the correlation between miR-618 rs2682818 C>A and risk of developing venous malformation in a southern Chinese population (1113 patients and 1158 controls). TaqMan genotyping of miR-618 rs2682818 C>A was conducted utilizing real-time fluorescent quantitative PCR. The miR-618 rs2682818 polymorphism was not correlated with susceptibility to venous malformation (CA/AA vs. CC: adjusted odds ratio [AOR] = 1.00, 95% confidence interval [CI] = 0.81-1.25, p = 0.994; AA vs. CC/CA: AOR = 1.10, 95% CI = 0.73-1.65, p = 0.646). Stratified analysis of different subtypes of venous malformation revealed that there was no significant difference in the rs2682818 C>A polymorphism genotypes across these subtypes. Our results indicate that miR-618 rs2682818 C>A polymorphism is not correlated with the susceptibility to venous malformation.

Significance of miRNAs on the thyroid cancer progression and resistance to treatment with special attention to the role of cross-talk between signaling pathways

Thyroid cancer (TC) is the most prevalent endocrine malignant tumor. It has many types, the Papillary thyroid cancer (PTC)(most common and follicular thyroid carcinoma (FTC). Several risk factors have been associated with TC radiation exposure, autoimmunity, and genetics. Microribonucleic acids (miRNAs) are the most important genetic determinants of TC. They are small chains of nucleic acids that are able to inhibit the expression of several target genes. They could target several genes involved in TC proliferation, angiogenesis, apoptosis, development, and even resistance to therapy. Besides, they could influence the stemness of TC. Moreover, they could regulate several signaling pathways such as WNT/β-catenin, PI3K/AKT/mTOR axis, JAK/STAT, TGF- β, EGFR, and P53. Besides signaling pathways, miRNAs are also involved in the resistance of TC to major treatments such as surgery, thyroid hormone-inhibiting therapy, radioactive iodine, and adjuvant radiation. The stability and sensitivity of several miRNAs might be exploited as an approach for the usage of miRNAs as diagnostic and/or prognostic tools in TC.

MiR-200c regulates invasion, proliferation and EMT of anaplastic thyroid cancer cells by targeting parathyroid hormone like hormone

This study aimed to explore the specific effect of miR-200c in anaplastic thyroid cancer (ATC). Hth74 and ARO cell lines were used. Proliferation, invasion, and colony formation activities of Hth74 and ARO cell lines affected by miR-200c were studied. Expression of epithelial-to-mesenchymal transition (EMT) markers (E-cadherin, N-cadherin, Slug, and Snail) in the Hth74 and ARO cell lines were validated by western blot and qRT-PCR. In addition, the regulation of the parathyroid hormone-like hormone (PTHLH) by miR-200c was assessed. Overexpression of miR-200c inhibited the invasion, proliferation, and colony formation of the ATC cell lines, whereas its downregulation achieved the opposite results. PTHLH was found to be regulated negatively by miR-200c through a miR-200c binding site within the 3'-UTR of PTHLH. miR-200c repressed the proliferation, invasion, and EMT process of cells in ATC cell lines by targeting PTHLH post-transcriptionally, which indicates that miR-200c may be a potential target for the treatment of ATC.

MicroRNAs as the critical regulators of cell migration and invasion in thyroid cancer

Thyroid cancer (TC) is one of the most frequent endocrine malignancies that is more common among females. Tumor recurrence is one of the most important clinical manifestations in differentiated TC which is associated with different factors including age, tumor size, and histological features. Various molecular processes such as genetic or epigenetic modifications and non-coding RNAs are also involved in TC progression and metastasis. The epithelial-to-mesenchymal transition (EMT) is an important biological process during tumor invasion and migration that affects the initiation and transformation of early-stage tumors into invasive malignancies. A combination of transcription factors, growth factors, signaling pathways, and epigenetic regulations affect the thyroid cell migration and EMT process. MicroRNAs (miRNAs) are important molecular factors involved in tumor metastasis by regulation of EMT-activating signaling pathways. Various miRNAs are involved in the signaling pathways associated with TC metastasis which can be used as diagnostic and therapeutic biomarkers. Since, the miRNAs are sensitive, specific, and non-invasive, they can be suggested as efficient and optimal biomarkers of tumor invasion and metastasis. In the present review, we have summarized all of the miRNAs which have been significantly involved in thyroid tumor cells migration and invasion. We also categorized all of the reported miRNAs based on their cellular processes to clarify the molecular role of miRNAs during thyroid tumor cell migration and invasion. This review paves the way of introducing a non-invasive diagnostic and prognostic panel of miRNAs in aggressive and metastatic TC patients.

EDDM3A drives gastric cancer progression by promoting HIF-1α-dependent aerobic glycolysis

Epididymal protein 3A (EDDM3A) is a protein involved in sperm maturation. It has been demonstrated that EDDM3A expression is upregulated and promotes cell proliferation in non-small cell lung cancer (NSCLC). However, the role of EDDM3A in other types of human cancers, including gastric cancer (GC), is still unexplored. Here, we show that the expression of EDDM3A is significantly upregulated in gastric cancer (GC) tissues and its upregulation correlates with poorer survival in patients with gastric cancer. Knockdown of EDDM3A inhibited growth and metastasis of GC cells, whereas overexpression of EDDM3A exhibited the opposite effect. Mechanistically, enhanced aerobic glycolysis mediated by upregulation of HIF-1α and subsequently increased target glycolytic genes and decreased mitochondrial biogenesis was found to contribute to the promotion of tumor growth and metastasis by EDDM3A in GC cells. Additionally, upregulation of EDDM3A in GC is at least partially mediated by downregulation of miR-618. In conclusion, elevated EDDM3A plays a pivotal oncogenic role in gastric carcinogenesis, suggesting it as a potential therapeutic target for treatment of GC.

Polymorphism rs2682818 participates in the progression of colorectal carcinoma via miR-618-TIMP1 regulatory axis

Colorectal carcinoma (CRC) has a high morbidity and mortality. Current studies have confirmed a variety of microRNA polymorphisms were associated with tumor susceptibility, however, the mechanisms are still unknown. In this study, we were aimed to clarify how polymorphism rs2682818 participated in the progression of CRC. First of all, the differential expression of miR-618 was assessed by quantitative real-time polymerase chain reaction in CRC patients with different genotypes of polymorphism rs2682818, including homozygous (TT) genotype, homozygous (GG) genotype and heterozygous (TG) genotype. Secondly, plasmids carried miR-168 precursor sequences harboring rs2682818 (SNP type) or without rs2682818 (wild type) were transfected into 293T cells to verify that polymorphism rs2682818 affected miR-618 expression. Thirdly, CCK-8 assay, flow cytometry assay, transwell assay and mouse xenograft assay were performed to measure the biological functions of miR-618 in CRC. Fourthly, the candidate target genes of miR-618 which were predicted by bioinformatics tools were verified by luciferase reporter assay. Finally, in order to explain the potential molecular mechanisms, western blotting was performed to demonstrate the differential expression and phosphorylation of pathway related proteins. The results showed that miR-618 was down-regulated in colon cancer, especially in CRC patients with rs2682818 GG homozygous genotype. Higher expression of mature miR-618 occurred in patients with TT homozygous genotype, and these patients usually had a longer survival time. Moreover, miR-618 mimic obviously impaired the growth and invasion ability of CRC cells, and miR-618 mimic also remarkably promoted CRC cell apoptosis. Our luciferase experiments confirmed that TIMP1 was a target of miR-618 in CRC cells. Knockdown of TIMP1 also significantly inhibited the malignant cytological features of CRC, including malignant growth and invasion as well as apoptosis resistance. In summary, polymorphism rs2682818 participated in the progression of CRC via affecting the expression of mature miR-618 in CRC cells, and miR-618 inhibited the progression of CRC via targeting TIMP1expression.

Poorly Differentiated and Anaplastic Thyroid Cancer: Insights into Genomics, Microenvironment and New Drugs

Simple Summary

In the last decades, many researchers produced promising data concerning genetics and tumor microenvironment of poorly differentiated thyroid cancer (PDTC) and anaplastic thyroid cancer (ATC). They are trying to tear the veil covering these orphan cancers, suggesting new therapeutic weapons as single or combined therapies.

Abstract

PDTC and ATC present median overall survival of 6 years and 6 months, respectively. In spite of their rarity, patients with PDTC and ATC represent a significant clinical problem, because of their poor survival and the substantial inefficacy of classical therapies. We reviewed the newest findings about genetic features of PDTC and ATC, from mutations occurring in DNA to alterations in RNA. Therefore, we describe their tumor microenvironments (both immune and not-immune) and the interactions between tumor and neighboring cells. Finally, we recapitulate how this upcoming evidence are changing the treatment of PDTC and ATC.

Epigenetic signature associated with thyroid cancer progression and metastasis

Thyroid cancer is not among the top cancers in terms of diagnosis or mortality but it still ranks fifth among the cancers diagnosed in women. Infact, women are more likely to be diagnosed with thyroid cancer than the males. The burden of thyroid cancer has dramatically increased in last two decades in China and, in the United States, it is the most diagnosed cancer in young adults under the age of twenty-nine. All these factors make it worthwhile to fully understand the pathogenesis of thyroid cancer. Towards this end, microRNAs (miRNAs) have constantly emerged as the non-coding RNAs of interest in various thyroid cancer subtypes on which there have been numerous investigations over the last decade and half. This comprehensive review takes a look at the current knowledge on the topic with cataloging of miRNAs known so far, particularly related to their utility as epigenetic signatures of thyroid cancer progression and metastasis. Such information could be of immense use for the eventual development of miRNAs as therapeutic targets or even therapeutic agents for thyroid cancer therapy.

Circulating miR-618 Has Prognostic Significance in Patients with Metastatic Colon Cancer

The present study evaluated the prognostic role of circulating miRNA-618 in patients with metastatic colon cancer (mCC) and whether miR-618 gene rs2682818 single nucleotide polymorphisms (SNP) are associated with colon cancer susceptibility and expression levels of mature miR-618. In total, 104 patients with mCC before starting the chemotherapy were investigated. The expression status of circulating miR-618 in mCC was evaluated by quantitative PCR. TaqMan PCR assay was used for rs2682818 SNP genotyping. miR-618 was overexpressed in serum of mCC patients. Patients with high and intermediate expression of miR-618 had a significantly longer mean overall survival (OS) of 21 months than patients with low expression—16 months. In addition, multivariate Cox regression analysis confirmed the association between high/intermediate levels of miRNA-618 and longer OS, HR = 0.51, 95% CI: 0.30–0.86, p = 0.012. miR-618 rs2682818 SNP significantly decreased the risk of colon cancer susceptibility in both heterozygous codominant (AC vs. CC, OR = 0.39, 95% CI: 0.17–0.88, p = 0.024) and overdominant (AC vs. CC + AA, OR = 0.37, 95% CI: 0.16–0.85, p = 0.018) genetic models. Our data suggest that circulating miRNA-618 could be useful as a prognostic biomarker in mCC. Patients harboring AC rs2682818 genotype have a decreased risk for colon cancer in comparison with patients with CC and AA genotypes.

Roles of Non-Coding RNAs on Anaplastic Thyroid Carcinomas

Anaplastic thyroid cancer (ATC) remains as one of the most aggressive human carcinomas with poor survival rates in patients with the cancer despite therapeutic interventions. Novel targeted and personalized therapies could solve the puzzle of poor survival rates of patients with ATC. In this review, we discuss the role of non-coding RNAs in the regulation of gene expression in ATC as well as how the changes in their expression could potentially reshape the characteristics of ATCs. A broad range of miRNA, such as miR-205, miR-19a, miR-17-3p and miR-17-5p, miR-618, miR-20a, miR-155, etc., have abnormal expressions in ATC tissues and cells when compared to those of non-neoplastic thyroid tissues and cells. Moreover, lncRNAs, such as H19, Human leukocyte antigen (HLA) complex P5 (HCP5), Urothelial carcinoma-associated 1 (UCA1), Nuclear paraspeckle assembly transcript 1 (NEAT1), etc., participate in transcription and post-transcriptional regulation of gene expression in ATC cells. Dysregulations of these non-coding RNAs were associated with development and progression of ATC by modulating the functions of oncogenes during tumour progression. Thus, restoration of the abnormal expression of these miRNAs and lncRNAs may serve as promising ways to treat the patients with ATC. In addition, siRNA mediated inhibition of several oncogenes may act as a potential option against ATC. Thus, non-coding RNAs can be useful as prognostic biomarkers and potential therapeutic targets for the better management of patients with ATC.

miR-618 rs2682818 C>A polymorphism decreases Hirschsprung disease risk in Chinese children

MicroRNAs (miRNAs) are endogenous non-coding small RNAs that play an important role in the development of many malignant tumors. In addition, recent studies have reported that single nucleotide polymorphisms (SNPs) located in the miRNA functional region was inextricably linked to tumor susceptibility. In the present study, we investigated the susceptibility between miR-618 rs2682818 C>A and Hirschsprung disease (HSCR) in the Southern Chinese population (1470 patients and 1473 controls). Odds ratios (ORs) and 95% confidence intervals (CIs) were used for estimating the strength of interrelation between them. We found that the CA/AA genotypes of miR-618 rs2682818 were associated with a decreased risk of HSCR when compared with the CC genotype (OR = 0.84, 95% CI = 0.72–0.99, P=0.032). Based on the stratified analysis of HSCR subtypes, the rs2682818 CA/AA genotypes were able to significantly lessen the risk of HSCR compared with CC genotype in patients with long-segment HSCR (adjusted OR = 0.70, 95% CI = 0.52–0.93, P=0.013). In conclusion, our results indicated that the miR-618 rs2682818 C>A polymorphism was associated with a reduced risk of HSCR in Chinese children, especially in patients with long-segment HSCR (L-HSCR) subtype.

Long Non-Coding RNA HOTAIR Modulates KLF12 to Regulate Gastric Cancer Progression via PI3K/ATK Signaling Pathway by Sponging miR-618

Purpose

Long non-coding RNA (lncRNA) HOX transcript antisense RNA (HOTAIR) has been reported to dysregulate in many tumors. However, the mechanism of HOTAIR was rarely reported in GC.

Methods

The levels of HOTAIR, microRNA-618 (miR-618) and Krueppel-like factor 12 (KLF12) in GC tissues and cells were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The cell viability and apoptotic rate were assessed via cell counting kit-8 (CCK-8) assay and flow cytometry, respectively. The migrating and invading abilities were tested by Transwell assay. The protein levels of KLF12, p-PI3K, PI3K, p-ATK and ATK were measured by Western blot assay. These interactions between miR-618 and HOTAIR or KLF12 were predicted by DIANA tools, and then, dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were conducted to validate these interactions. Besides, the xenograft tumor experiment was performed to further verify the roles of HOTAIR in GC.

Results

The levels of HOTAIR and KLF12 were significantly upregulated and the level of miR-618 was strikingly downregulated in GC tissues and cells. miR-618 was verified as a direct target of HOTAIR or KLF12. HOTAIR silencing blocked GC progression and PI3K/ATK signaling pathway by sponging miR-618 and also restrained xenograft tumor growth in vivo. miR-618 inhibited GC progression and PI3K/ATK signaling pathway by targeting KLF12. Mechanistically, HOTAIR modulated KLF12 expression by sponging miR-618 in GC cells.

Conclusion

These data unraveled that HOTAIR promoted GC progression through PI3K/ATK signaling pathway via miR-618/KLF12 axis.

MicroRNA-618 Directly Targets Metadherin mRNA To Suppress The Malignant Phenotype Of Osteosarcoma Cells By Reducing PTEN-AKT Pathway Output

Purpose

Dysregulation of microRNA-618 (miR-618) has been observed in multiple types of human cancer. However, whether miR-618 is implicated in osteosarcoma (OS) initiation and progression is still unclear. Hence, we measured the expression of miR-618 in OS tissues and cell lines. In addition, the roles of miR-618 and the mechanisms underlying its activities in OS cells were examined.

Methods

The expression status of miR-618 in OS was analyzed by reverse-transcription quantitative PCR. The regulatory roles of miR-618 overexpression in OS were explored by the Cell Counting Kit-8 assay, flow-cytometric analysis, Transwell cell migration and invasion assays, and a tumor xenograft experiment.

Results

The results revealed that the expression of miR-618 was notably lower in OS tissues and cell lines, and that the low miR-618 expression significantly correlated with the clinical stage and distant metastasis among patients with OS. Exogenous miR-618 expression significantly suppressed OS cell proliferation, migration, and invasion and induced apoptosis in vitro as well as slowed tumor growth in vivo. Mechanism investigation indicated that metadherin (MTDH) is a direct target gene of miR-618 in OS cells. A knockdown of MTDH mimicked the tumor-suppressive effects of miR-618 upregulation on OS cells. Notably, resumption of MTDH expression attenuated the miR-618–mediated reduction in OS cell growth and metastasis in vitro. In addition, miR-618 overexpression reduced the PTEN–AKT pathway output in OS cells both in vitro and in vivo through downregulation of MTDH.

Conclusion

To the best of our knowledge, this is the first study to show that miR-618 exerts crucial tumor-suppressive actions in OS pathogenesis by directly targeting MTDH mRNA and reducing PTEN–AKT pathway output. These results will help to elucidate the functions of miR-618 in OS and suggest that this miRNA may be investigated as a therapeutic target in this disease.

Does miR-618 rs2682818 variant affect cancer susceptibility? Evidence from 10 case-control studies

Piles of evidence have supported the relationship between miR-618 rs2682818 polymorphism and tumorigenesis, but the conclusion remains inconsistent. In the present study, we conducted a meta-analysis to sniff out the potential risk between miR-618 rs2682818 and overall cancers. Crude odds ratios (ORs) and 95% confidence intervals (CIs) analyzed by Z-test were employed to estimate the potential interrelation in five genetic models. We also prospected how the rs2682818 affects the second structure of miR-618. Finally, 10 independent studies meet the enrolled criteria, along with 4099 cancer cases and 5057 healthy controls. Overall, no exceeding interrelation was sniffed out in the pooled data among five inherited models, as well as stratified analyses. Whereas, the enhanced cancer risk of miR-618 rs2682818 variant stratified by breast cancer was revealed, in heterozygote genetic model (AC vs. CC: OR = 1.291, 95%CI = 1.012-1.648, P = 0.040) and dominant contrast model (AA + AC vs. CC: OR = 1.280, 95%CI = 1.009-1.623, P = 0.042). The second structure prediction result shown that the mutant A allele might change the first stem-loop of miR-618, and the free energy of it would turn from -39.1 to -35.1 kcal/mol. All in all, our meta-analysis had successfully chased down that miR-618 rs2682818 polymorphism is not linked with overall cancer risk, but in the dominant genotype of breast cancer.

Long intergenic non-protein coding RNA 511 promotes the progression of osteosarcoma cells through sponging microRNA 618 to upregulate the expression of maelstrom

Osteosarcoma is a tumor disease that commonly exists among young populations. Our research explored the role of the LINC00511/microRNA-618/MAEL axis in osteosarcoma.Expression profiles of long non-coding RNAs (lncRNAs) in osteosarcoma (OS) tissues were constructed, and LINC00511 expression levels were verified with qRT-PCR. LncRNA-miRNA and miRNA-mRNA interactions were predicted. Validation was performed using a dual-luciferase reporter assay. Protein expression levels of MAEL were evaluated by Western blot assays. The effects of LINC00511, miR-618 and MAEL on the proliferation, viability, and metastasis of OS cells were detected using colony formation, cell counting kit-8 (CCK-8) and transwell assays, respectively. The apoptosis rates of OS cells were investigated using flow cytometry. The tumor-suppressing effect of LINC00511 silencing was also analyzed using a xenograft model in nude mice.LINC00511 overexpression was observed in OS tissues and cell lines. Knockdown of LINC00511 in nude mice inhibited the tumorigenic ability of OS cells. Transfection-induced overexpression of LINC00511 and MAEL, as well as downregulation, highlighted the features of tumor cells, and LINC00511 overexpression reduced apoptosis in vitro.LINC00511 was confirmed to be beneficial for osteosarcoma development via sponging miR-618 and increasing MAEL expression and may thus be considered a potential target for osteosarcoma therapy.

miR-618 Suppresses Metastasis in Gastric Cancer by Downregulating the Expression of TGF-β2

Recent studies have demonstrated that microRNAs regulate gene expression and are related to cancer progression. Increasing evidence shows that miR-618 plays an important role in a variety of tumors, including thyroid carcinomas, breast cancer and lymphoma cancer. However, no studies have examined the expression or function of miR-618 in gastric cancer (GC). In this study, we examined the effects and molecular mechanisms of miR-618 in GC. We compared the expression levels of miR-618 in 90 paired GC tissues and adjacent noncancerous tissues. Cell cycle, apoptosis and transwell assays were performed in GC cells with miR-618 mimic or inhibitor in vitro. We first used quantitative PCR(qPCR) to show that miR-618 expression levels were downregulated in GC tissues, which showed statistical significance. Next we used transwell assays to prove that miR-618 suppressed the invasion and migration capacity of GC cells. Furthermore, screening of the miRDB and Target Scan Human databases indicated TGF-β2 as a downstream target of miR-618. In further research, we identified TGF-β2 as a target gene of miR-618 by the luciferase reporter assay. Western blot analysis confirmed that TGF-β2 expression was inversely correlated with miR-618 expression. In situ hybridization showed that miR-618 expression level was downregulated in GC tissues. In conclusion, our findings suggest that miR-618 may function as a tumor suppressor in GC and suppresses metastasis in GC by negatively regulating the transcriptional level of TGF-β2. Anat Rec, 302:931-940, 2019. © 2019 Wiley Periodicals, Inc.

Altered Epigenetic Mechanisms in Thyroid Cancer Subtypes

Thyroid carcinoma (TC) is the most frequent malignant neoplasm of the endocrine system. Molecular methods for diagnosis of invasive thyroid disease can be effectively adopted. Epigenetic factors play an important role in the diversity patterns of gene expression and the phenotypic and biological characteristics of TC subtypes. We aimed to review epigenetic changes in the main subtypes of TC, along with a presentation of the methods that have examined these changes, and active clinical trials for the treatment of advanced TCs targeting epigenetic changes. A literature analysis was performed in MEDLINE using PubMed, Elsevier, and Google Scholar for studies published up to 2016, using the keywords: "Epigenetic alterations" OR "Epigenetic changes", "thyroid cancers", "papillary thyroid cancer", "medullary thyroid cancer", "follicular thyroid cancer", and "anaplastic thyroid cancer", which resulted in 310 articles in English. All related abstracts were reviewed and studies were included that were published in English, had available full text, and determined the details of the methods and materials associated with the epigenetic patterns of TC and its subtypes (100 articles). Analysis of epigenetic alterations in TC subtypes helps to identify pathogenesis and can play an important role in the classification and diagnosis of tumors. Epigenetic mechanisms, especially aberrant methylation of DNA and microRNAs (miRs), are likely to play an important role in thyroid tumorigenesis. Further studies are required to elucidate the role of histone modification mechanisms in TC development.

Epigenetic modifications in poorly differentiated and anaplastic thyroid cancer

Well-differentiated thyroid cancer accounts for the majority of endocrine malignancies and, in general, has an excellent prognosis. In contrast, the less common poorly differentiated thyroid carcinoma (PDTC) and anaplastic thyroid carcinoma (ATC) are two of the most aggressive human malignancies. Recently, there has been an increased focus on the epigenetic alterations underlying thyroid carcinogenesis, including those that drive PDTC and ATC. Dysregulated epigenetic candidates identified include the Aurora group, KMT2D, PTEN, RASSF1A, multiple non-coding RNAs (ncRNA), and the SWI/SNF chromatin-remodeling complex. A deeper understanding of the signaling pathways affected by epigenetic dysregulation may improve prognostic testing and support the advancement of thyroid-specific epigenetic therapies. This review outlines the current understanding of epigenetic alterations observed in PDTC and ATC and explores the potential for exploiting this understanding in developing novel therapeutic strategies.

miR-618 Inhibits Prostate Cancer Migration and Invasion by Targeting FOXP2

miRNAs play critical role in the development and progression of prostate cancer. Here we studied the role of miR-618 in prostate cancer migration and invasion. miR-618 was downregulated in metastatic androgen-independent prostate cancer (AIPC), patients with low miR-618 had poor outcome. Overexpression of miR-618 inhibited migration and invasion and induced mesenchymal to epithelial transition (MET). Conversely, knockdown of miR-618 promoted migration and invasion and induced epithelial to mesenchymal transition (EMT). FOXP2 was the direct target of miR-618, and promoted TGF-β expression, inhibition of TGF-β reversed the effect of miR-618 knockdown. We further analyzed the correlation between miR-618 expression and FOXP2 in human prostate cancer tissues, and found there was a negative correlation between miR-618 expression and FOXP2 levels. In conclusion, we found miR-618 inhibited prostate cancer migration and invasion by targeting FOXP2 and inhibiting TGF-β.

Lentivirus-mediated miR-23a overexpression induces trophoblast cell apoptosis through inhibiting X-linked inhibitor of apoptosis

Preeclampsia (PE) is a pregnancy-specific disorder representing a major cause of maternal and perinatal morbidity and mortality. MicroRNAs (miRNAs) have emerged as critical regulators in PE. However, the precise role of miRNAs in PE remains poorly understood. In this study, we aimed to investigate the potential role of miR-23a and the underlying mechanism in regulating trophoblast cell apoptosis. We found a significant increase of miR-23a expression in placental tissues from PE patients. Lentivirus-mediated miR-23a overexpression significantly induced apoptosis in trophoblast cells in vitro. X-linked inhibitor of apoptosis (XIAP) was identified as a target gene of miR-23a by bioinformatics analysis and dual-luciferase reporter assay. Overexpression of miR-23a significantly inhibited XIAP expression. Knockdown of XIAP also induced trophoblast cell apoptosis. Moreover, restoration of XIAP expression significantly abolished the miR-23 overexpression-induced trophoblast cell apoptosis. Taken together, our study demonstrates that miR-23a induces trophoblast cell apoptosis by inhibiting XIAP, which may contribute to PE. Our findings provide novel insights into understanding the pathogenesis of PE and suggest a potential therapeutic target in PE.

miR-182 promotes tumor growth and increases chemoresistance of human anaplastic thyroid cancer by targeting tripartite motif 8

Chemotherapy is one of the most effective forms of cancer treatment and has been used in the treatment of various malignant tumors. We have gained significant insight into the mechanisms of chemoresistance but the details of the molecular mechanisms remain unclear. In the present study, we found that tripartite motif 8 (TRIM8) expression was downregulated in anaplastic thyroid cancer (ATC) tissues and cell lines. This downregulation of TRIM8 was significantly correlated with the upregulation of miR-182 in human ATC tissues. Bioinformatic analysis and luciferase reporter assays identified TRIM8 as a direct target of miR-182 in ATC. A functional assay using an MTT assay and colony formation showed that miR-182 induced cellular growth by repressing TRIM8 expression. Additionally, overexpressed miR-182 contributed to the chemoresistance of ATC cells by the repression of TRIM8 expression. In conclusion, these results demonstrate that miR-182/TRIM8 may be a therapeutic target for the treatment of chemoresistant human thyroid papillary cancer.

miR-148a inhibits self-renewal of thyroid cancer stem cells via repressing INO80 expression

Anaplastic thyroid carcinoma (ATC) is aggressive and lethal with extrathyroidal invasion, distant metastasis, and resistance to conventional therapies. Cancer stem cells (CSCs) are proposed to be responsible for high recurrence rate in ATC. MicroRNAs (miRNAs) have recently been found as an important class of cellular regulators of ATC carcinogenesis. Identification of CSC-related miRNAs and targets is therefore a priority for the development of new therapeutic paradigms. Patient-derived ATC cells were cultured in conditional media on poly-hema-treated dish. ATC CSCs were isolated and enriched through as a series of steps including initial isolation of sphere-forming CSC population, subsequent amplification of this CSC population in a xenograft model treated with cisplatin, and purification of CSCs from xenograft tumors followed by final enrichment using sphere-forming assays. Expression of CSC markers was measured by flow cytometry, immunofluorescence staining, qPCR and western blot analyses. Expression of miRNAs in ATC-CSCs was profiled by microarray analysis. Proliferation and differentiation rates were determined based on the size of spheres formed in vitro and tumors formed in vivo. We successfully isolated and enriched an ATC-CSC population. We identified 17 miRNAs differentially expressed in primary ATC cells vs. ATC-CSCs, among which miRNA-148a was significantly downregulated in ATC-CSCs. Overexpression of miRNA148a in ATC-CSCs induced cell cycle arrest and loss of stem cell characteristics. In addition, we identified INO80 as a target gene of miR-148a. The expression of INO80 was upregulated in ATC-CSCs and downregulated upon miRNA-148 overexpression. Overexpression of miRNA-148a and knockdown of INO80 acted synergistically to decrease the expression of stem cell marker genes as well as to attenuate stem cell-specific properties including the ability to form tumors. This study identified novel contrasting roles for miR-148a and INO80 in the regulation of the stemness of ATC-CSCs and their capacity to initiate tumor formation. Our findings may open a new avenue for therapeutic development against ATC that targets INO80 in the CSCs through enhancing miRNA-148a levels.

microRNA regulators of apoptosis in cancer

This brief review summarizes our current knowledge on the microRNAs that regulate apoptosis machinery and are potentially involved in the dysregulation or deregulation of apoptosis, a well known hallmark of cancer. microRNAs are critical regulators of the most important cellular processes, including apoptosis. Expression of microRNAs is found to be dysregulated in many malignancies, leading to apoptosis inhibition in cancer, or resistance to current therapies. To date, there are over 80 microRNAs directly involved in apoptosis regulation or dysregulation that can impact cancer detection, initiation, progression, invasion, metastasis or resistance to anti-cancer therapy. Development of microRNA-based therapeutic strategies is now taking shape in the clinic. Thus, these microRNAs represent potential targets or tools for cancer therapy in the future.

Schizophrenia-Associated MIR204 Regulates Noncoding RNAs and Affects Neurotransmitter and Ion Channel Gene Sets

As regulators of gene expression, microRNAs (miRNAs) are likely to play an important role in the development of disease. In this study we present a large-scale strategy to identify miRNAs with a role in the regulation of neuronal processes. Thereby we found variant rs7861254 located near the MIR204 gene to be significantly associated with schizophrenia. This variant resulted in reduced expression of miR-204 in neuronal-like SH-SY5Y cells. Analysis of the consequences of the altered miR-204 expression on the transcriptome of these cells uncovered a new mode of action for miR-204, being the regulation of noncoding RNAs (ncRNAs), including several miRNAs, such as MIR296. Furthermore, pathway analysis showed downstream effects of miR-204 on neurotransmitter and ion channel related gene sets, potentially mediated by miRNAs regulated through miR-204.