Identification of differential expressed lncRNAs in human thyroid cancer by a genome-wide analyses

Biomarkers in Thyroid Cancer: Emerging Opportunities from Non-Coding RNAs and Mitochondrial Space

Thyroid cancer diagnosis primarily relies on imaging techniques and cytological analyses. In cases where the diagnosis is uncertain, the quantification of molecular markers has been incorporated after cytological examination. This approach helps physicians to make surgical decisions, estimate cancer aggressiveness, and monitor the response to treatments. Despite the availability of commercial molecular tests, their widespread use has been hindered in our experience due to cost constraints and variability between them. Thus, numerous groups are currently evaluating new molecular markers that ultimately will lead to improved diagnostic certainty, as well as better classification of prognosis and recurrence. In this review, we start reviewing the current preoperative testing methodologies, followed by a comprehensive review of emerging molecular markers. We focus on micro RNAs, long non-coding RNAs, and mitochondrial (mt) signatures, including mtDNA genes and circulating cell-free mtDNA. We envision that a robust set of molecular markers will complement the national and international clinical guides for proper assessment of the disease.

LINC00092 Enhances LPP Expression to Repress Thyroid Cancer Development via Sponging miR-542-3p

LINC00092 is poorly expressed in Thyroid cancer (TC), while its role in TC tumorigenesis is still elusive. This study aimed to reveal the role and regulatory mechanism of LINC00092 in TC.RNA immunoprecipitation and dual luciferase reporter assays were employed to ascertain the relationships among lipoma preferred partner (LPP), miR-542-3p, and LINC00092. qRT-PCR analysis was performed to detect their expression levels in TC. LPP protein productions were evaluated via western blotting. CCK-8, transwell, and colony formation assays were done to estimate TC cells' biological functions. A murine xenograft model was built to observe tumor formation in vivo.LINC00092 overexpression decreased the expression levels of miR-542-3p, and LPP was targeted by miR-542-3p. In TC cells and tissues, the elevation of miR-542-3p, and low amounts of LINC00092 and LPP can be observed. Both LINC00092 and SPAG6 were considered as the antineoplastic factors in TC since their overexpression dramatically repressed TC cells' invasive and proliferative potentials, while miR-542-3p exerted the opposite functions in TC. The ectopic expression of LINC00092 also suppressed tumor growth in vivo. In addition, it revealed that miR-542-3p upregulation reversed LINC00092 overexpression-mediated effects on TC cells. At the same time, the enhanced influences of TC cells caused by miR-542-3p upregulation could be attenuated by the enforced LPP.This study innovatively reveals that LINC00092 acts as an antineoplastic lncRNA to restrain the development of TC via regulating miR-542-3p/LPP. The findings of this study may provide a prospective drug target on LINC00092/miR-542-3p/LPP axis for the treatment of TC.

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.

Beyond ribosome biogenesis: noncoding nucleolar RNAs in physiology and tumor biology

The nucleolus, the largest subcompartment of the nucleus, stands out from the nucleoplasm due to its exceptionally high local RNA and low DNA concentrations. Within this central hub of nuclear RNA metabolism, ribosome biogenesis is the most prominent ribonucleoprotein (RNP) biogenesis process, critically determining the structure and function of the nucleolus. However, recent studies have shed light on other roles of the nucleolus, exploring the interplay with various noncoding RNAs that are not directly involved in ribosome synthesis. This review focuses on this intriguing topic and summarizes the techniques to study and the latest findings on nucleolar long noncoding RNAs (lncRNAs) as well as microRNAs (miRNAs) in the context of nucleolus biology beyond ribosome biogenesis. We particularly focus on the multifaceted roles of the nucleolus and noncoding RNAs in physiology and tumor biology.

Somatic Copy Number Alterations in Colorectal Cancer Lead to a Differentially Expressed ceRNA Network (ceRNet)

Colorectal cancer (CRC) represents the second deadliest malignancy worldwide. Around 75% of CRC patients exhibit high levels of chromosome instability that result in the accumulation of somatic copy number alterations. These alterations are associated with the amplification of oncogenes and deletion of tumor-ppressor genes and contribute to the tumoral phenotype in different malignancies. Even though this relationship is well known, much remains to be investigated regarding the effect of said alterations in long non-coding RNAs (lncRNAs) and, in turn, the impact these alterations have on the tumor phenotype. The present study aimed to evaluate the role of differentially expressed lncRNAs coded in regions with copy number alterations in colorectal cancer patient samples. We downloaded RNA-seq files of the Colorectal Adenocarcinoma Project from the The Cancer Genome Atlas (TCGA) repository (285 sequenced tumor tissues and 41 non-tumor tissues), evaluated differential expression, and mapped them over genome sequencing data with regions presenting copy number alterations. We obtained 78 differentially expressed (LFC > 1|< -1, padj < 0.05) lncRNAs, 410 miRNAs, and 5028 mRNAs and constructed a competing endogenous RNA (ceRNA) network, predicting significant lncRNA-miRNA-mRNA interactions. Said network consisted of 30 lncRNAs, 19 miRNAs, and 77 mRNAs. To understand the role that our ceRNA network played, we performed KEGG and GO analysis and found several oncogenic and anti-oncogenic processes enriched by the molecular players in our network. Finally, to evaluate the clinical relevance of the lncRNA expression, we performed survival analysis and found that C5orf64, HOTAIR, and RRN3P3 correlated with overall patient survival. Our results showed that lncRNAs coded in regions affected by SCNAs form a complex gene regulatory network in CCR.

Emerging role of T3-binding protein μ-crystallin (CRYM) in health and disease

Thyroid hormones are essential metabolic and developmental regulators that exert a huge variety of effects in different organs. Triiodothyronine (T3) and thyroxine (T4) are synthesized in the thyroid gland and constitute unique iodine-containing hormones that are constantly regulated by a homeostatic feedback mechanism. T3/T4 activity in cells is mainly determined by specific transporters, cytosolic binding proteins, deiodinases (DIOs), and nuclear receptors. Modulation of intracellular T3/T4 level contributes to the maintenance of this regulatory feedback. μ-Crystallin (CRYM) is an important intracellular high-affinity T3-binding protein that buffers the amount of T3 freely available in the cytosol, thereby controlling its action. In this review, we focus on the molecular and pathological properties of CRYM in thyroid hormone signaling, with emphasis on its critical role in malignancies.

Links between Breast and Thyroid Cancer: Hormones, Genetic Susceptibility and Medical Interventions

Breast and thyroid glands are two common sites of female malignancies. Since the late 19th century, physicians have found that the cancers in either thyroid or mammary gland might increase the risk of second primary cancers in the other site. From then on, many observational clinical studies have confirmed the hypothesis and more than one theory has been developed to explain the phenomenon. Since the two glands both have secretory functions and are regulated by the hypothalamic-pituitary axis, they may share some common oncogenic molecular pathways. However, other risks factors, including medical interventions and hormones, are also observed to play a role. This article aims to provide a comprehensive review of the associations between the two cancers. The putative mechanisms, such as hormone alteration, autoimmune attack, genetic predisposition and other life-related factors are reviewed and discussed. Medical interventions, such as chemotherapy and radiotherapy, can also increase the risk of second primary cancers. This review will provide novel insights into the research designs, clinical managements and treatments of thyroid and breast cancer patients.

LncRNA-PAX8-AS1 Silencing Decreases Cell Viability, Enhances Apoptosis, and Suppresses Doxorubicin Resistance in Myeloid Leukemia via the miR-378g/ERBB2 Axis

Objective

Considering the role of lncRNAs reported as regulators in acute myeloid leukemia (AML) progression, the current research aims to investigate the role of PAX8-AS1 in chemo-resistant AML.

Methods

Human AML cells HL60 and human doxorubicin (ADM)-resistant AML cells (HL60/ADM cells) were used to establish in vitro models of chemo-sensitive AML and refractory/recurrent AML, respectively. CCK-8 assay and flow cytometry were used to determine cell resistance to ADM, viability, and apoptosis. PAX8-AS1, miR-378g, and ERBB2 expressions in the models and/or AML patients were quantified via qRT-PCR or Western blot. The miRNA/mRNA axis targeted by PAX8-AS1 was analyzed using Starbase, TargetScan, or GEO and validated through a dual-luciferase reporter assay. The expressions of Bcl-2, Bax, and C Caspase-3 in cells were quantitated by Western blot.

Results

The highly expressed PAX8-AS1 was observed in AML patients and HL60 cells, which was more evident in refractory/recurrent AML patients and HL60/ADM cells. Compared with that in ADM-treated parental HL60 cells, the viability of ADM-treated HL60/ADM cells remained strong. PAX8-AS1 overexpression increased viability and Bcl-2 expression, while diminishing apoptosis, Bax, and C Caspase-3 expressions in HL60 cells. However, the abovementioned aspects were oppositely impacted by PAX8-AS1 silencing in HL60/ADM cells. PAX8-AS1 directly targeted miR-378g, whose expression pattern is opposite to that of PAX8-AS1 in AML. MiR-378g upregulation abrogated the effects of PAX8-AS1 overexpression on HL60 cells. MiR-378g downregulation offset PAX8-AS1 silencing-induced effects on HL60/ADM cells. Moreover, ERBB2 was recognized as the target of miR-378g, with a higher expression in HL60/ADM cells than in HL60 cells.

Conclusion

PAX8-AS1 silencing decreases cell viability, enhances apoptosis, and suppresses ADM resistance in AML via regulating the miR-378g/ERBB2 axis.

Construction of miRNA-lncRNA-mRNA co-expression network affecting EMT-mediated cisplatin resistance in ovarian cancer

Platinum resistance is one of the major concerns in ovarian cancer treatment. Recent evidence shows the critical role of epithelial-mesenchymal transition (EMT) in this resistance. Epithelial-like ovarian cancer cells show decreased sensitivity to cisplatin after cisplatin treatment. Our study prospected the association between epithelial phenotype and response to cisplatin in ovarian cancer. Microarray dataset GSE47856 was acquired from the GEO database. After identifying differentially expressed genes (DEGs) between epithelial-like and mesenchymal-like cells, the module identification analysis was performed using weighted gene co-expression network analysis (WGCNA). The gene ontology (GO) and pathway analyses of the most considerable modules were performed. The protein-protein interaction network was also constructed. The hub genes were specified using Cytoscape plugins MCODE and cytoHubba, followed by the survival analysis and data validation. Finally, the co-expression of miRNA-lncRNA-TF with the hub genes was reconstructed. The co-expression network analysis suggests 20 modules relating to the Epithelial phenotype. The antiquewhite4, brown and darkmagenta modules are the most significant non-preserved modules in the Epithelial phenotype and contain the most differentially expressed genes. GO, and KEGG pathway enrichment analyses on these modules divulge that these genes were primarily enriched in the focal adhesion, DNA replication pathways and stress response processes. ROC curve and overall survival rate analysis show that the co-expression pattern of the brown module's hub genes could be a potential prognostic biomarker for ovarian cancer cisplatin resistance.

LINC00704 contributes to the proliferation and accelerates the cell cycle of nasopharyngeal carcinoma cells via regulating ETS1/CDK6 axis

This study is aimed at exploring the biological functions and related mechanism of long noncoding RNA 704 (LINC00704) in the proliferation and cell cycle progression of nasopharyngeal carcinoma (NPC) cells. The expression of LINC00704 in NPC tissues and cells was quantified by quantitative real-time polymerase chain reaction (qRT-PCR). After LINC00704 was overexpressed or knocked down in NPC cell lines, cell counting kit-8 (CCK-8) assay, 5-bromo-2'-deoxyuridine assay, flow cytometry assay, and Transwell assay were adopted to detect the proliferation, cell cycle progression, migration, and invasion of NPC cells. The interaction between LINC00704 and ETS proto-oncogene 1 (ETS1) was verified by bioinformatics analysis, RNA pull-down assay, and RNA immunoprecipitation assay. Dual-luciferase reporter gene assay and chromatin immunoprecipitation followed by qPCR analysis were used to verify the binding status between ETS1 and the promoter region of cyclin-dependent kinase 6 (CDK6). The regulatory effects of LINC00704 and ETS1 on CDK6 expression were detected by Western blot. LINC00704 expression was elevated in NPC tissues and cells, which was significantly correlated with the advanced TNM stage and poor differentiation. LINC00704 overexpression promoted the multiplication, migration, and invasion of NPC cells and blocked the cell cycle progression while knocking down LINC00704 worked oppositely. LINC00704 could bind to ETS1, thus promoting CDK6 transcription. Knocking down LINC00704 inhibited the CDK6 expression in NPC cells. LINC00704 promotes CDK6 transcription by recruiting ETS1 to the promoter region of CDK6, thus promoting the malignant progression of NPC.

lncRNA RUNDC3A-AS1 Regulates Proliferation and Apoptosis of Thyroid Cancer Cells via the miR-151b/SNRPB Axis

The number of thyroid cancer (THCA) cases has increased dramatically worldwide. Many previous reports have confirmed that lncRNA is involved in the pathogenesis of THCA. However, the role and mechanism of lncRNA RUNDC3A-AS1 in THCA have not been studied. We intended to explore the effect of RUNDC3A-AS1 on the proliferation and apoptosis of THCA cells. Relative expression levels of RUNDC3A-AS1, microRNA (miR)-151b, and small nuclear ribonucleoprotein polypeptides B and B1 (SNRPB) were examined by reverse transcription quantitative polymerase chain reaction (RT-qPCR) in THCA cells. The localization of RUNDC3A-AS1 in THCA cells was detected by subcellular fractionation assay. The cell proliferation was tested by 5-ethynyl-2'-deoxyuridine (EdU), cell counting kit-8 (CCK-8), and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. Flow cytometry was used to examine the cell apoptosis capacity. The relationships between RUNDC3A-AS1 and miR-151b or miR-151b and SNRPB were verified by luciferase reporter assay. The protein level was detected by Western blot analysis. RUNDC3A-AS1 exhibited high expression in THCA cells. RUNDC3A-AS1 knockdown suppressed cell proliferation but induced cell apoptosis. Importantly, RUNDC3A-AS1 targeted miR-151b to regulate the SNRPB expression. In rescue assays, SNRPB overexpression partially reversed the suppressive effect of RUNDC3A-AS1 knockdown on cell proliferation and the promotive effect of RUNDC3A-AS1 knockdown on cell apoptosis. The RUNDC3A-AS1/miR-151b/SNRPB axis regulated THCA cell proliferation and apoptosis, which provides novel insight into THCA investigation at the molecular level.

BRD4 promotes heterotopic ossification through upregulation of LncRNA MANCR

Aims

Acquired heterotopic ossification (HO) is a debilitating disease characterized by abnormal extraskeletal bone formation within soft-tissues after injury. The exact pathogenesis of HO remains unknown. It was reported that BRD4 may contribute to osteoblastic differentiation. The current study aims to determine the role of BRD4 in the pathogenesis of HO and whether it could be a potential target for HO therapy.

Methods

Achilles tendon puncture (ATP) mouse model was performed on ten-week-old male C57BL/6J mice. One week after ATP procedure, the mice were given different treatments (e.g. JQ1, shMancr). Achilles tendon samples were collected five weeks after treatment for RNA-seq and real-time quantitative polymerase chain reaction (RT-qPCR) analysis; the legs were removed for micro-CT imaging and subsequent histology. Human bone marrow mesenchymal stem cells (hBMSCs) were isolated and purified bone marrow collected during surgeries by using density gradient centrifugation. After a series of interventions such as knockdown or overexpressing BRD4, Alizarin red staining, RT-qPCR, and Western Blot (Runx2, alkaline phosphatase (ALP), Osx) were performed on hBMSCs.

Results

Overexpression of BRD4 enhanced while inhibition of Brd4 suppressed the osteogenic differentiation of hBMSCs in vitro. Overexpression of Brd4 increased the expression of mitotically associated long non-coding RNA (Mancr). Downregulation of Mancr suppressed the osteoinductive effect of BRD4. In vivo, inhibition of BRD4 by JQ1 significantly attenuated pathological bone formation in the ATP model (p = 0.001).

Conclusion

BRD4 was found to be upregulated in HO and Brd4-Mancr-Runx2 signalling was involved in the modulation of new bone formation in HO.

Cite this article: Bone Joint Res 2021;10(10):668–676.

Combined molecular and mathematical analysis of long noncoding RNAs expression in fine needle aspiration biopsies as novel tool for early diagnosis of thyroid cancer

PURPOSE

In presence of indeterminate lesions by fine needle aspiration (FNA), thyroid cancer cannot always be easily diagnosed by conventional cytology. As a consequence, unnecessary removal of thyroid gland is performed in patients without cancer based on the lack of optimized diagnostic criteria. Aim of this study is identifying a molecular profile based on long noncoding RNAs (lncRNAs) expression capable to discriminate between benign and malignant nodules.

METHODS

Patients were subjected to surgery (n = 19) for cytologic suspicious thyroid nodules or to FNA biopsy (n = 135) for thyroid nodules suspicious at ultrasound. Three thyroid-specific genes (TG, TPO, and NIS), six cancer-associated lncRNAs (MALAT1, NEAT1, HOTAIR, H19, PVT1, MEG3), and two housekeeping genes (GAPDH and P0) were analyzed using Droplet Digital PCR (ddPCR).

RESULTS

Based on higher co-expression in malignant (n = 11) but not in benign (n = 8) nodules after surgery, MALAT1, PVT1 and HOTAIR were selected as putative cancer biomarkers to analyze 135 FNA samples. Cytological and histopathological data from a subset of FNA patients (n = 34) were used to define a predictive algorithm based on a Naïve Bayes classifier using co-expression of MALAT1, PVT1, HOTAIR, and cytological class. This classifier exhibited a significant separation capability between malignant and benign nodules (P < 0.0001) as well as both rule in and rule out test potential with an accuracy of 94.12% and a negative predictive value (NPV) of 100% and a positive predictive value (PPV) of 91.67%.

CONCLUSIONS

ddPCR analysis of selected lncRNAs in FNA biopsies appears a suitable molecular tool with the potential of improving diagnostic accuracy.

Silencing long non-coding RNAs nicotinamide nucleotide transhydrogenase antisense RNA 1 inhibited papillary thyroid cancer cell proliferation, migration and invasion and promoted apoptosis via targeting miR-199a-5p

The increasing incidence of papillary thyroid cancer (PTC) has attracted many researchers to investigate the mechanism underlying PTC progression. This study explored the growth and apoptosis of PTC cells based on an lncRNA regulatory mechanism. The expression of nicotinamide nucleotide transhydrogenase antisense RNA 1 (NNT-AS1) in PTC cell lines and PTC tissues was analyzed by qRT-PCR. The mutual binding site between NNT-AS1 and miR-199a-5p was predicted by starBase and confirmed by dual-luciferase reporter assay. The correlation between NNT-AS1 and miR-199a-5p was shown by Pearson correlation test. The viability, clone formation, migration, invasion and apoptosis of TPC-1 and IHH-4 cells were examined by CCK-8, colony formation, wound-healing, transwell, and flow cytometry assays, respectively. The expressions of Bax, cleaved Caspase-3, Bcl-2, E-Cadherin, N-Cadherin and SNAIL in TPC-1 and IHH-4 cells were determined by Western blot or qRT-PCR. NNT-AS1 expression was upregulated in PTC cells and tissues. In TPC-1 cells, silencing NNT-AS1 inhibited viability, clone formation, migration, and invasion as well as the expressions of N-Cadherin, SNAIL and Bcl-2, but promoted the expressions of E-Cadherin, Bax, and cleaved caspase-3. The effects of NNT-AS1 overexpression on IHH-4 cells were opposite to those of silencing NNT-AS1. In PTC tissues, miR-199a-5p was low-expressed and targeted by NNT-AS1, and it was negatively correlated with NNT-AS1. MiR-199a-5p inhibitor promoted TPC-1 cell progression, but miR-199a-5p mimic inhibited IHH-4 cell progression. NNT-AS1 and miR-199a-5p exerted opposite effects on PTC cells. Silencing NNT-AS1 inhibited PTC cell proliferation, migration and invasion, but promoted apoptosis via upregulation of miR-199a-5p.

Long Non-coding RNA RUNDC3A-AS1 Promotes Lung Metastasis of Thyroid Cancer via Targeting the miR-182-5p/ADAM9

Long non-coding RNAs (lncRNAs) have been identified as influential indicators in variety of malignancies. Among which, LncRNA RUNDC3A-AS1 is reported to upregulate in thyroid cancer. However, the expression pattern and the pathological function of lncRNA RUNDC3A-AS1 in thyroid cancer is unclear. In this study, we examined the expression levels of lncRNA RUNDC3A-AS1 in the thyroid cancer tissues and cell lines via RT-qPCR analysis. The effects of RUNDC3A-AS1 on thyroid cancer cell metastasis were detected by transwell chamber assay, scratch assay in vitro and lung metastasis model in vivo. The results indicated that RUNDC3A-AS1 was highly expressed in the thyroid cancer tissues and cell lines. Functionally, knockdown of RUNDC3A-AS1 could repress the migration and invasion of thyroid cancer cells in vitro, and inhibit thyroid cancer metastasis to lung in vivo. Mechanistically, RUNDC3A-AS1 served as an inhibitor of miR-182-5p in tumor tissues and cell lines. RUNDC3A-AS1 inhibited the expression of miR-182-5p to increase the expression level of ADAM9, thus further aggravating the malignancy of thyroid cancer. Therefore, the RUNDC3A-AS1/miR-182-5p/ADAM9 axis may be a potential therapeutic target for the treatment of thyroid cancer metastasis.

Long non-coding RNA LIFR-AS1 regulates the proliferation, migration and invasion of human thyroid cancer cells

The long non-coding RNA (lncRNA) LIFR-AS1 has been shown to be involved in the development of several human cancers. This study was designed to determine the expression profile and role of lncRNA-LIFR-AS1 in human thyroid cancer. The results showed significant (p < 0.05) upregulation of LncRNA-LIFR-AS1 in thyroid cancer tissues and cells. However, silencing of LncRNA-LIFR-AS1 inhibited the viability and proliferation of human thyroid cancer cells inducing G2/M cell cycle arrest. The G2/M phase cells increased from 8.56% in negative control (NC) to around 35.03% in si-LIFR-AS1. This was also found to be concomitant with the downregulation of cyclin B1 and CDK1 expressions. The thyroid cancer cells exhibited remarkably lower invasion and migration under transcriptional knockdown of lncRNA-LIFR-AS1 which was also associated with downregulation of MMP-2 and MMP-9 expression. Importantly, transcriptional silencing of lncRNA-LIFR-AS1 inhibited thyroid cancer tumorigenesis, in vivo. Collectively, the results suggest the tumor-promoting role of lncRNA-LIFR-AS1 in thyroid cancer and highlight its potential as therapeutic target.

Long non-coding RNA-regulated pathways in pancreatic β cells: Their role in diabetes

Long non-coding RNAs (lncRNAs) are transcripts of more than 200 nucleotides that have not coding potential, but act as gene expression regulators through several molecular mechanisms. Several studies have identified tons of lncRNAs that are expressed in pancreatic β cells and many of them have been shown to have β cell-specific expression, suggesting a potential role in the regulation of basal β cell functions. Indeed, accumulating evidence based on numerous studies, has highlighted the implication of lncRNAs in the regulation of pancreatic β cell differentiation and proliferation, insulin synthesis and secretion, and apoptosis. In addition, several lncRNAs have shown to be implicated in pancreatic β cell dysfunction linked to different types of diabetes, including type 1 and type 2 diabetes, and monogenic forms of the disease. Pathogenic conditions linked to diabetes (inflammation or lipoglucotoxicity, for example) dysregulate the expression of several lncRNAs, suggesting that changes in lncRNA may alter potentially important pathways for β cell function, and eventually leading to β cell dysfunction and diabetes development. In this sense, functional characterization of some lncRNAs has demonstrated that these non-coding molecules participate in the regulation of several crucial pathways at the pancreatic β cell level, and dysregulation of these pathways leads to pathogenic phenotypes. In this review, we provide an overview of the action mechanisms of functionally characterized lncRNAs in healthy β cells and describe the contribution of some diabetes-associated lncRNAs to pancreatic β cell failure.

The regulatory effect of 6-TG on lncRNA-miRNA-mRNA ceRNA network in triple-negative breast cancer cell line

Breast cancer is one of the most prevalent and recurring cancer types that leads to deaths in women. Triple-negative breast cancer (TNBC) is difficult to treat due to the lack of therapeutic targets. Many studies have focused on identifying drugs for use as alternative treatments for breast cancer. Thioguanine (6-TG) exerts antitumor effects in cancer. Increasing evidence has demonstrated that competitive endogenous ribonucleic acids (ceRNAs) are involved in cancer processes. However, the mechanism by which 6-TG regulates lncRNA-miRNA-mRNAs has not been elucidated. We evaluated the antitumor effect of 6-TG in MDA-MB-231 cells and comprehensively analyzed the RNA-Seq data of MDA-MB-231 cells treated with 6-TG. Our results showed that most tumor pathways were blocked by 6-TG. The hub genes were FN1, FLNA, FLNB, VCL, GSN, MYH10, ACTN4, KDR and EREG, and they were all down-regulated after 6-TG treatment. The coexpression network consisted of 18 microRNAs (miRNAs), 9 long noncoding RNAs (lncRNAs) and 20 mRNAs. Hsa-mir-16-5p and Hsa-mir-335-5p targeted the greatest number of mRNAs in the network. These molecules could bind to PAX8-AS1 and eliminate the inhibition of target mRNA expression. We showed that PAX8-AS1 is the main lncRNA affected by 6-TG and that PAX8-AS1 regulates the hub genes in tumor pathways by competitively binding with miR-16-5p and miR-335-5p.

Overexpression of PAX8-AS1 Inhibits Malignant Phenotypes of Papillary Thyroid Carcinoma Cells via miR-96-5p/PKN2 Axis

BACKGROUND

Thyroid carcinoma (THCA) is the most frequent endocrine malignancy. Papillary thyroid carcinoma (PTC) is the major subtype of THCA, accounting for over 80% of all THCA cases. LncRNA PAX8-AS1, a tumor suppressor associated with various human cancers, has been reported to be relevant to the regulation of all sorts of cellular processes. The purpose of this study was to verify the role of PAX8-AS1 in PTC.

METHODS

Three human PTC cell lines (K1, TPC-1, and IHH4) and one normal human thyroid cell line, Nthy-ori3-1, were used in our study. The expression of genes was detected by qRT-PCR. The bioinformatic analysis and luciferase reporter assay were used to confirm the binding relationship of PAX8-AS1 to miR-96-5p, and the targeting relationship of miR-96-5p to PKN2 was also predicted. Cell proliferation and apoptosis capacities were assessed by MTT and flow cytometry, respectively. EdU assay was used to detect cell proliferation. Western blot assay was employed to examine protein expression.

RESULTS

The expression of PAX8-AS1 was decreased in PTC tissues and cells. PAX8-AS1 overexpression inhibited the proliferation of PTC cells and promoted cell apoptosis. In addition, PAX8-AS1 bonds with miR-96-5p, whose downregulation elevated the expression of PKN2 in PTC cells. Importantly, according to the rescue experiments, PKN2 silencing partially reversed the inhibitory effects of PAX8-AS1 expression on PTC cell proliferation and apoptosis.

CONCLUSIONS

We found that the PAX8-AS1/miR-96-5p/PKN2 axis was closely related to the progression of PTC, which could be a potential target for treating PTC patients.

A competing endogenous RNA network reveals key lncRNAs associated with sepsis

BACKGROUND

This study set out to determine key lncRNAs correlated with sepsis via constructing competing endogenous RNA (ceRNA) network.

METHODS

Three septic patients and three healthy controls were recruited to obtain lncRNA profiles in this current study. Combined with the mRNA profiles by RNA-sequencing, an integrated analysis of mRNA expression profiles downloaded from GEO was performed to obtain the differentially expressed mRNAs (DEmRNAs). Based on differentially expressed lncRNAs (DElncRNAs) and DEmRNAs acquired in this present study and differentially expressed miRNAs (DEmiRNAs) acquired in previous study, a ceRNA network was constructed. Furthermore, LINC00963 was validated in THP-1 cells by performing loss of function assays.

RESULTS

In this analysis, a total of 290 DEmRNAs and 46 DElncRNAs were detected in sepsis. Parkinson's disease, Oxidative phosphorylation and Cardiac muscle contraction were significantly enriched KEGG pathways in sepsis. XPO1, CUL4A, and NEDD8 were three hub proteins of sepsis-specific PPI network. A ceRNA network, which contained 16 DElncRNA-DEmiRNA pairs and 82 DEmiRNA-DEmRNA pairs, involving 5 lncRNAs, 10 miRNAs, and 60 mRNAs, was obtained. The function experiments indicated that knockdown of LINC00963 could promote cell proliferation, reduce cytokine expression, and suppress inflammasome activation and phagocytosis in LPS-induced THP-1 cells.

CONCLUSION

This study determined key lncRNAs involved in sepsis, which may contribute to the development for novel treatment strategy of sepsis.

Mitotically associated long non-coding RNA is a tumor promoter in anaplastic thyroid cancer

Background

Patients with anaplastic thyroid cancer (ATC), which is among the deadliest of all cancers, often have a poor response to traditional therapies. Currently, the role of long non-coding RNAs (lncRNAs) in ATC carcinogenesis is unclear. In this study, we analyzed the lncRNA expression profile of ATC with the aim of identifying potential molecular targets for treatment of the disease.

Methods

Whole transcriptome sequencing of three ATC and two normal thyroid (NT) samples was performed, and the lncRNA expression profile of ATC was analyzed. Original data as well as datasets deposited in the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) were used for clinical validation. Cell proliferation, Transwell, and apoptosis assays were performed using ATC cell lines. Gene Ontology (GO) and gene set enrichment analyses (GSEA) were performed to determine the dysregulated pathways.

Results

Whole transcriptome sequencing revealed 182 lncRNAs to be differentially expressed in ATC. One of the lncRNAs, mitotically associated long non-coding RNA (MANCR; LINC00704), was significantly overexpressed in ATC cell lines and patient samples compared with NT and papillary thyroid cancer (PTC). MANCR depletion in ATC cells significantly inhibited cancer cell proliferation and invasion, and induced apoptosis. By further analyzing the transcriptome data, we identified 451 genes co-expressed with MANCR. GO and GSEA showed that the top dysregulated pathways were related to mitosis and cell cycle.

Conclusions

MANCR is a tumor promoter in ATC, and its role in carcinogenesis is possibly associated with cell cycle regulation. Because MANCR expression is minimal in most normal tissues, it may serve as a potential target in the future treatment of ATC.

Identification and validation of methylation-driven genes prognostic signature for recurrence of laryngeal squamous cell carcinoma by integrated bioinformatics analysis

Background

Recurrence remains a major obstacle to long-term survival of laryngeal squamous cell carcinoma (LSCC). We conducted a genome-wide integrated analysis of methylation and the transcriptome to establish methylation-driven genes prognostic signature (MDGPS) to precisely predict recurrence probability and optimize therapeutic strategies for LSCC.

Methods

LSCC DNA methylation datasets and RNA sequencing (RNA-seq) dataset were acquired from the Cancer Genome Atlas (TCGA). MethylMix was applied to detect DNA methylation-driven genes (MDGs). By univariate and multivariate Cox regression analyses, five genes of DNA MDGs was developed a recurrence-free survival (RFS)-related MDGPS. The predictive accuracy and clinical value of the MDGPS were evaluated by receiver operating characteristic (ROC) and decision curve analysis (DCA), and compared with TNM stage system. Additionally, prognostic value of MDGPS was validated by external Gene Expression Omnibus (GEO) database. According to 5 MDGs, the candidate small molecules for LSCC were screen out by the CMap database. To strengthen the bioinformatics analysis results, 30 pairs of clinical samples were evaluated by digoxigenin-labeled chromogenic in situ hybridization (CISH).

Results

A total of 88 DNA MDGs were identified, and five RFS-related MDGs (LINC01354, CCDC8, PHYHD1, MAGEB2 and ZNF732) were chosen to construct a MDGPS. The MDGPS can effectively divide patients into high-risk and low-risk group, with the area under curve (AUC) of 0.738 (5-year RFS) and AUC of 0.74 (3-year RFS). Stratification analysis affirmed that the MDGPS was still a significant statistical prognostic model in subsets of patients with different clinical variables. Multivariate Cox regression analysis indicated the efficacy of MDGPS appears independent of other clinicopathological characteristics. In terms of predictive capacity and clinical usefulness, the MDGPS was superior to traditional TNM stage. Additionally, the MDGPS was confirmed in external LSCC cohorts from GEO. CMap matched the 9 most significant small molecules as promising therapeutic drugs to reverse the LSCC gene expression. Finally, CISH analysis in 30 LSCC tissues and paired adjacent normal tissues revealed that MAGEB2 has significantly higher expression of LSCC compared to adjacent non-neoplastic tissues; LINC01354, CCDC8, PHYHD1, and ZNF732 have significantly lower expression of LSCC compared to adjacent non-neoplastic tissues, which were in line with bioinformatics analysis results.

Conclusion

A MDGPS, with five DNA MDGs, was identified and validated in LSCC patients by combining transcriptome and methylation datasets analysis. Compared TNM stage alone, it generates more accurate estimations of the recurrence prediction and maybe offer novel research directions and prospects for individualized treatment of patients with LSCC.

Clinical significance of CCNE2 protein and mRNA expression in thyroid cancer tissues

PURPOSE

Thyroid carcinoma (TC) is the most common endocrinal malignancy worldwide. Cyclin E2 (CCNE2), a member of the cyclin family, acts as a regulatory subunit of cyclin-dependent kinases (CDKs). It controls the transition of quiescent cells into the cell cycle, regulates the G1/S transition, promotes DNA replication, and activates CDK2. This study explored the role and potential molecular mechanisms of CCNE2 expression in TC tissues.

MATERIAL/METHODS

Immunohistochemistry was used to evaluate the CCNE2 protein expression levels in TC. High-throughput data on CCNE2 in TC were obtained from RNA sequencing (RNA-seq), microarray, and literature data. The CCNE2 expression levels in TC were comprehensively assessed through an integrated analysis. Analyses of Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and protein-protein interaction (PPIs) data facilitated the investigation of the relative molecular mechanisms of CCNE2 in TC.

RESULTS

The immunohistochemical experiment showed a significant increase in the expression of CCNE2 in the TC tissues. For 505 TC and 59 non-cancerous samples from RNA-seq data, the area under the curve (AUC) was 0.8016 (95% confidence interval [CI] 0.742-0.8612; p<0.001). With another 14 microarrays, the pool standard mean difference [SMD] was 1.01 (95% CI [0.82-1.19]). The pooled SMD of CCNE2 was 1.12 (95% CI [0.60-1.64]), and the AUC was 0.87 (95% CI [0.84-0.90]) for 1157 TC samples and 366 non-cancerous thyroid samples from all possible sources. Nine hub genes were upregulated in TC.

CONCLUSIONS

A high expression of CCNE2 may lead to carcinogenesis and the development of TC.

Long non-coding RNA LINC00704 promotes cell proliferation, migration, and invasion in papillary thyroid carcinoma via miR-204-5p/HMGB1 axis

Papillary thyroid carcinoma (PTC) is a common malignancy worldwide. LncRNA LINC00704 (mitotically associated long non-coding RNA) was reported as a crucial regulator in PTC. However, the biological mechanism of LINC00704 action remains unclear in PTC. The mRNA levels of LINC00704, miR-204-5p, and high-mobility group box 1 (HMGB1) were measured by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assay. HMGB1, proliferating cell nuclear antigen (PCNA), and cyclin D1 protein levels were detected using the Western blot assay. The binding relationship between miR-204-5p and LINC00704 or HMGB1 was predicted by LncBase Predicted v.2 or TargetScan, respectively, and then validated by dual luciferase reporter assay. Cell viability, cell cycle, cell migration and invasion, and migration ratio were assessed by MTT, flow cytometry, transwell cell migration and invasion, and wound-healing assays, respectively. Results suggested that LINC00704 and HMGB1 were elevated and miR-204-5p decreased in PTC tissues and cells. Furthermore, rescue experiments demonstrated that the miR-204-5p inhibitor alleviated the inhibitory effects of LINC00704 knockdown on cell proliferation, cell cycle, migration, and invasion. Meanwhile, miR-204-5p overexpression repressed proliferation, migration, and invasion by targeting HMGB1. Mechanical analysis discovered that LINC00704 could act as an miR-204-5p sponge to modulate HMGB1 expression. In conclusion, LINC00704 promoted PTC cell proliferation, cell cycle, migration, and invasion by the miR-204-5p/HMGB1 axis, providing a novel therapeutic target for PTC patients.

Molecular mechanisms of long non-coding RNAs in anaplastic thyroid cancer: a systematic review

BACKGROUND

anaplastic thyroid cancer (ATC) is one of the most lethal and aggressive cancers. Evidence has shown that the tumorigenesis of ATC is a multistep process involving the accumulation of genetic and epigenetic changes. Several studies have suggested that long non-coding RNAs (lncRNAs) may play an important role in the development and progression of ATC. In this article, we have collected the published reports about the role of lncRNAs in ATC.

METHODS

"Scopus", "Web of Science", "PubMed", "Embase", etc. were systematically searched for articles published since 1990 to 2020 in English language, using the predefined keywords.

RESULTS

961 papers were reviewed and finally 33 papers which fulfilled the inclusion and exclusion criteria were selected. Based on this systematic review, among a lot of evidences on examining the function of lncRNAs in thyroid cancer, there are only a small number of studies about the role of lncRNAs and their molecular mechanisms in the pathogenesis of ATC.

CONCLUSIONS

lncRNAs play a crucial role in regulation of different processes involved in the development and progression of ATC. Currently, just a few lncRNAs have been identified in ATC that may serve as prognosis markers such as GAS5, MIR22HG, and CASC2. Also, because of the dysregulation of Klhl14-AS, HOTAIRM1, and PCA3 during ATC development and progression, they may act as therapeutic targets. However, for most lncRNAs, only a single experiment has evaluated the expression profile in ATC tissues/cells. Therefore, further functional studies and expression profiling is needed to resolve this limitation and identify novel and valid biomarkers.

In Silico Analysis Identifies Differently Expressed lncRNAs as Novel Biomarkers for the Prognosis of Thyroid Cancer

Background

Thyroid cancer (TC) is one of the most common type of endocrine tumors. Long noncoding RNAs had been demonstrated to play key roles in TC. Material and Methods. The lncRNA expression data were downloaded from Co-lncRNA database. The raw data was normalized using the limma package in R software version 3.3.0. The differentially expressed mRNA and lncRNAs were identified by the linear models for the microarray analysis (Limma) method. The DEGs were obtained with thresholds of ∣logFC∣ > 1.5 and P < 0.001. The hierarchical cluster analysis of differentially expressed mRNAs and lncRNAs was performed using CLUSTER 3.0, and the hierarchical clustering heat map was visualized by Tree View.

Results

In the present study, we identified 6 upregulated and 85 downregulated lncRNAs in TC samples. Moreover, we for the first time identified 16 downregulated lncRNAs was correlated to longer disease-free survival time in patients with TC, including ATP1A1-AS1, CATIP-AS1, FAM13A-AS1, LINC00641, LINC00924, MIR22HG, NDUFA6-AS1, RP11-175K6.1, RP11-727A23.5, RP11-774O3.3, RP13-895J2.2, SDCBP2-AS1, SLC26A4-AS1, SNHG15, SRP14-AS1, and ZNF674-AS1.

Conclusions

Bioinformatics analysis revealed these lncRNAs were involved in regulating the RNA metabolic process, cell migration, organelle assembly, tRNA modification, and hormone levels. This study will provide useful information to explore the potential candidate biomarkers for diagnosis, prognosis, and drug targets for TC.

Long non-coding RNA MANCR is a target of BET bromodomain protein BRD4 and plays a critical role in cellular migration and invasion abilities of prostate cancer

Androgen receptor (AR)-negative castration-resistant prostate cancer (CRPC) is highly aggressive and is resistant to most of the current therapies. Bromodomain and extra terminal domain (BET) protein BRD4 binds to super-enhancers (SEs) that drive high expression of oncogenes in many cancers. A BET inhibitor, JQ1, has been found to suppress the malignant phenotypes of prostate cancer cells, however, the target genes of JQ1 remain largely unknown. Here we show that SE-associated genes specific for AR-negative CRPC PC3 cells include genes involved in migration and invasion, and that JQ1 impairs migration and invasion of PC3 cells. We identified a long non-coding RNA, MANCR, which was markedly down-regulated by JQ1, and found that BRD4 binds to the MANCR locus. MANCR knockdown led to a significant decrease in migration and invasion of PC3 cells. Furthermore, RNA sequencing analysis revealed that expression of the genes involved in migration and invasion was altered by MANCR knockdown. In summary, our data demonstrate that MANCR plays a critical role in migration and invasion of PC3 cells.

Identification of a Multi-RNA-Type-Based Signature for Recurrence-Free Survival Prediction in Patients with Uterine Corpus Endometrial Carcinoma

Uterine corpus endometrial carcinoma (UCEC) is one of the leading causes of death from gynecological cancer due to the high recurrence rate. A recent study indicated that molecular biomarkers can enhance the recurrence prediction power if they were integrated with clinical information. In this study, we attempted to identify a new multi-RNA-type-based molecular biomarker for predicting the recurrence risk and recurrence-free survival (RFS). Matched mRNA (including lncRNA) and miRNA RNA-sequencing data from 463 UCEC patients (n = 75, recurrent; n = 388, non-recurrent) were downloaded from The Cancer Genome Atlas database. LASSO (least absolute shrinkage and selection operator) analysis was used to screen the optimal combination of prognostic RNAs and then the risk score model was constructed. Moreover, the molecular mechanisms of prognostic RNAs were explored by establishing various interaction networks based on corresponding predictive databases. A multi-RNA-type-based signature (including three miRNAs: hsa-miR-6511b, hsa-miR-184, hsa-miR-4461; three lncRNAs: ENO1-IT1, MCCC1-AS1, AATBC; and 7 mRNAs: EPPK1, ASB9, BDNF, CYP11A1, ECEL1, EN2, F13A1) was developed for the prediction of RFS. The risk scoring system established by these signature genes was effective for the discrimination of the 5-year RFS in the high-risk from low-risk patients in the training [an area under the receiver operating characteristic curve (AUC) = 0.960], validation (AUC = 0.863), and entire datasets (AUC = 0.873). This risk score model was also proved to be a more excellent, independent prognostic discriminator than the single-RNA-type (overall AUC: 0.947 vs. 0.677, lncRNAs; 0.709, miRNAs; 0.899, mRNAs) and clinical staging (overall AUC: 0.947 vs. 0.517). Furthermore, the downstream mechanisms for some prognostic miRNAs or lncRNAs (HAND2-AS1-hsa-miR-6511b-APC2, PAX8-AS1-hsa-miR-4461-TNIK and MCCC1-AS1/ENO1-IT1-TNIK) were newly predicted based on the coexpression or competitive endogenous RNA theories. In conclusion, our findings may provide novel biomarkers for recurrence prediction and targets for treatment of UCEC.

Integrative Analysis of Methylation and Transcriptome Identified Epigenetically Regulated lncRNAs With Prognostic Relevance for Thyroid Cancer

Emerging evidence has shown that epigenetic changes in DNA methylation, an important regulator of long non-coding RNA (lncRNA) expression, can disturb the expression patterns of lncRNAs and contribute to carcinogenesis. However, knowledge about crosstalk effects between DNA methylation and lncRNA regulation in thyroid cancer (THCA) remain largely unknown. In this study, we performed an integrated analysis of methylation and the transcriptome and identified 483 epigenetically regulated lncRNAs (EpilncRNAs) associated with the development and progression of THCA. These EpilncRNAs can be divided into two categories based on their methylation and expression patterns: 228 HyperLncRNAs and 255 HypoLncRNAs. Then, we identified a methylation-driven 5-lncRNA-based signature (EpiLncPM) to improve prognosis prediction using the random survival forest and multivariate Cox analysis, which were then validated using the training dataset [Hazard ratio (HR) = 50.097, 95% confidence interval (CI): 10.231-245.312, p < 0.001] and testing dataset (HR = 4.395, 95% CI: 0.981-19.686, p = 0.053). Multivariate analysis suggested that the EpiLncPM is an independent prognostic factor. By performing a functional enrichment analysis of GO and KEGG for mRNAs co-expressed with the EpiLncPM, we found that the EpiLncPM was involved in immune and inflammatory-related biological processes. Finally, in situ hybridization analysis in 119 papillary thyroid carcinoma (PTC) tissues and paired adjacent normal tissues revealed that selected candidate lncRNA AC110011 has significantly higher expression of PTC compared to adjacent non-neoplastic tissues, and was closely related to the tumor size, lymph node metastasis, and extrathyroidal extension. In summary, our study characterized the crosstalk between DNA methylation and lncRNA, and provided novel biomarkers for the prognosis of THCA.

Expression and functional analysis of lncRNAs in the hippocampus of immature rats with status epilepticus

Long non-coding RNAs (lncRNAs) have been implicated in the regulation of gene expression at various levels. However, to date, the expression profile of lncRNAs in status epilepticus (SE) was unclear. In our study, the expression profile of lncRNAs was investigated by high-throughput sequencing based on a lithium/pilocarpine-induced SE model in immature rats. Furthermore, weighted correlation network analysis (WGCNA), gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed to construct co-expression networks and establish functions of the identified hub lncRNAs in SE. The functional role of a hub lncRNA (NONRATT010788.2) in SE was investigated in an in vitro model. Our results indicated that 7082 lncRNAs (3522 up-regulated and 3560 down-regulated), which are involved in cell proliferation, inflammatory responses, angiogenesis and autophagy, were dysregulated in the hippocampus of immature rats with SE. Additionally, WGCNA identified 667 up-regulated hub lncRNAs in turquoise module that were involved in apoptosis, inflammatory responses and angiogenesis via regulation of HIF-1, p53 and chemokine signalling pathways and via inflammatory mediator regulation of TRP channels. Knockdown of an identified hub lncRNA (NONRATT010788.2) inhibited neuronal apoptosis in vitro. Taken together, our study is the first to demonstrate the expression profile and potential function of lncRNAs in the hippocampus of immature rats with SE. The defined hub lncRNAs may participate in the pathogenesis of SE via lncRNA-miRNA-mRNA network.

The role of long non-coding RNAs in the pathogenesis of thyroid cancer

Long noncoding RNAs (lncRNAs) as prominent regulators of gene expression are involved in different layers of expression regulation. These transcripts participate in carcinogenesis of several human malignancies including thyroid cancer. Availability of high throughput techniques such as RNA sequencing and microarray has facilitated identification of lncRNAs whose dysregulation affect tumorigenesis process. Moreover, assessment of differentially expressed lncRNAs between resistant and sensitive cells has led to recognition of biomarkers for therapeutic response. One elucidated aspect of lncRNAs functions is their role in sponging miRNAs. Several miRNA-lncRNA-mRNA triplets have been recognized till now. Any of these triplets is a putative target of interfering with the evolution of cancer. In the current study, we have summarized recent data in the fields of biology of lncRNAs, their role in thyroid cancer and their potential as biomarker or treatment target.

Up-regulation of long non-coding RNA AWPPH inhibits proliferation and invasion of gastric cancer cells via miR-203a/DKK2 axis

AWPPH is a newly discovered long non-coding RNA (lncRNA). However, the expression and function of AWPPH in gastric cancer (GC) have not yet been clarified. This study tries to assess the expression and biological roles of AWPPH in GC and the underlying mechanism. The expression of lncRNA AWPPH was evaluated in GC tissues and adjacent normal tissues from 40 patients. Cell Counting Kit-8 (CCK8) and transwell assays were applied to assess cell proliferation and invasion capabilities. Bioinformatics tool was employed to predict AWPPH's sponging miRNA, while luciferase reporter assays were used to verify the target. LncRNA AWPPH was remarkably downregulated in GC and associated with metastasis. CCK8 and transwell assays proved that AWPPH inhibited cell proliferation and invasion in GC cells. MiR-203a was a predicted and further verified target of AWPPH. DKK2 was verified as a direct target of miR-203a. Upregulation of miR-203a attenuated the repressive effects of AWPPH on GC cell proliferation and invasion. AWPPH inhibited GC cell proliferation and invasion via miR-203a/DKK2 axis. This finding might provide new insight for the potential therapeutic strategies for GC in the future.

The Long Non-Coding RNA ENST00000489676 Influences Papillary Thyroid Cancer Cell Proliferation and Invasion through Regulating MiR-922

Purpose: Long noncoding RNAs (lncRNAs) have been reported to be associated with the growth and progression of numerous cancers. The aim of this study was to explore the potential function and molecular mechanism of lncRNA ENST00000489676 in the proliferation and invasion of papillary thyroid cancer (PTC). Methods: QRT-PCR (quantitative reverse transcriptase-polymerase chain reaction) was used to determine the levels of ENST00000489676. CCK-8 (Cell Counting Kit-8) assay and colony formation assay were performed to detect the cell proliferation. Flow cytometry was used to analyze the cell cycle. Transwell and scratch assay were performed to detect the migration and invasion ability. Results: The expression of ENST00000489676 was significantly overexpressed in TPC1 compared to KTC1 cell lines. When ENST00000489676 expression was knocked down, the proliferation, migration and invasion ability as well as cell cycle were all promoted in PTC cell lines, while those abilities were all suppressed when ENST00000489676 overexpressed. Overexpression of ENST00000489676 could inhibit cell proliferation, migration and invasion in vitro. Moreover, ENST00000489676 may mediate tumor suppression in PTC cells through suppressing miR-922. Conclusions: ENST00000489676 negatively regulated the proliferation, migration invasion and cell cycle of PTC. The overexpression of ENST00000489676 inhibited the progression of PTC through suppressing miR-922. ENST00000489676 could be act as a novel diagnosis marker and a potential therapeutic target for PTC.

Linc00210 enhances the malignancy of thyroid cancer cells by modulating miR-195-5p/IGF1R/Akt axis

Emerging evidence has indicated that long noncoding RNA (lncRNAs) play crucial roles in regulating thyroid cancer (TC) development. Linc00210 is a newly identified lncRNA which plays an oncogenic role in hepatocellular carcinoma and nasopharyngeal carcinoma, but whether Linc00210 can modulate the development of TC remains elusive. Here, we found that Linc00210 expression was upregulated in TC tissues compared to the matched noncancerous tissues. Overexpression of Linc00210 augmented the proliferation, migration, and invasion of TC cells. Mechanistically, Linc00210 served as a sponge for miR-195-5p, thereby counteracting its ability in downregulating the expression of IGF1R and the activation of PI3K/Akt signaling. Moreover, inhibition of Linc00210 suppressed the growth of TC cells in nude mice. Our findings for the first time uncovered the oncogenic property of Linc00210 in TC.

Prognostic value of long non-coding RNA FOXD2-AS1 expression in patients with solid tumors

BACKGROUND

Although increasing evidence has revealed that FOXD2-AS1 overexpression exists in various solid tumors, the value of FOXD2-AS1 as a prognostic marker in such cancers remains uncertain. Accordingly, the present research aimed to assess the association of FOXD2-AS1 with cancer prognosis and predict the biological function of FOXD2-AS1.

METHODS

We systematically retrieved PubMed, PMC, Web of Science, EMBASE and Wiley Online Library databases for eligible articles published up to December 2018. Pooled hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (95%CIs) were calculated to evaluate the correlation of FOXD2-AS1 expression with overall survival (OS), disease free survival (DFS) and clinicopathological characteristics. We also used five Gene Expression Omnibus (GEO) datasets from breast cancer patients to explore the relationship between FOXD2-AS1 expression and prognosis. Finally, we validated FOXD2-AS1 expression in various carcinomas and predicted its biological function based on the public databases.

RESULTS

A total of 13 studies with 2502 tumor patients were included. The pooled HRs demonstrated that FOXD2-AS1 overexpression was significantly associated with unfavorable OS (HR = 1.39, 95%CI: 1.23-1.57, p < 0.001) and DFS (HR = 2.24, 95%CI: 1.55-3.23, p < 0.001) in tumor patients. The pooled ORs indicated that FOXD2-AS1 upregulation was related to large tumor size (OR = 1.53, 95%CI: 1.26-1.85, p < 0.001), deep invasion depth (OR = 1.99, 95%CI: 1.53-2.58, p < 0.001), distant metastasis (OR = 2.03, 95%CI: 1.69-2.43, p < 0.001) and advanced TNM stage (OR = 1.35, 95%CI: 1.06-1.72, p = 0.0150), but not to lymph node metastasis nor differentiation. Moreover, a similar pooled result for the OS of breast cancer patients was obtained (HR = 1.55, 95%CI: 1.14-2.11, p = 0.0052) by analyzing GEO data. Finally, elevated FOXD2-AS1 expression in various solid tumor tissues was verified based on The Cancer Genome Atlas (TCGA) data. Further functional prediction demonstrated that FOXD2-AS1 may participate in some cancer-related pathways.

CONCLUSION

Elevated FOXD2-AS1 expression was associated with poor survival in patients with solid tumors and may serve as a potential prognostic biomarker for a variety of cancers.

FOXD2-AS1 correlates with the malignant status and regulates cell proliferation, migration, and invasion in cutaneous melanoma

Long noncoding RNA (lncRNA) FOXD2 adjacent opposite strand RNA 1 (FOXD2-AS1) has been shown to be dysregulated in several types of human cancer. However, the role of FOXD2-AS1 in cutaneous melanoma was still unclear. In our study, FOXD2-AS1 expression has been found to be upregulated in cutaneous melanoma tissue specimens and cell lines compared with that in normal tissue specimens and normal human epidermal melanocyte, respectively. Furthermore, high expression of FOXD2-AS1 was obviously correlated with deep Breslow thickness, present ulceration, high Clark level and distant metastasis in cutaneous melanoma patients. However, there were no statistical associations between FOXD2-AS1 expression and cutaneous melanoma patients' disease-free survival and overall survival. The results of loss-of-function study showed that inhibition of FOXD2-AS1 suppresses cutaneous melanoma cell proliferation, migration and invasion through regulating phospho-Akt expression. In conclusion, FOXD2-AS1 is associated with clinical progression in cutaneous melanoma patients, and functions as oncogenic lncRNA in cutaneous melanoma cells.

Oncogenicity of lncRNA FOXD2-AS1 and its molecular mechanisms in human cancers

OBJECTIVES

Long non-coding RNAs (lncRNAs) are a group of noncoding RNAs with length larger than 200 nucleotides. LncRNAs have limited or no protein-coding capacity because of lack of obvious open reading frame. An increasing number of researches have shown that lncRNAs participate in the complex regulation network of cancer and play an important role in tumourigenesis and progression such as proliferation, migration and invasion. LncRNA FOXD2 adjacent opposite strand RNA 1 (FOXD2-AS1), located on chromosome 1p33 and with a transcript length of 2527 nucleotides, is a novel cancer-related lncRNA. FOXD2-AS1 was recently found to exhibit aberrant expression in various malignancies, including gastric, lung, bladder, colorectal, nasopharyngeal, esophageal, hepatocellular, thyroid and skin cancer, and its deregulation might be related to survival and prognosis of cancer patients. Pertinent to clinical practice, FOXD2-AS1 might act as a feasible biomarker or therapeutic target in human cancers. In this paper, we made a summary on the current findings concerning the biological functions and molecular mechanisms of FOXD2-AS1 in tumor progression.

MATERIALS AND METHODS

In this paper, we summarized and figured out recent studies about the expression and molecular biological mechanisms of FOXD2-AS1 in tumor progression. Existing relevant studies were obtained through a systematic search from PubMed, Embase, BioMedNet, GEO database and Cochrane Library.

RESULTS

FOXD2-AS1 was a valuable tumor-associated lncRNA. Its expression level was up-regulation in various malignancies, including gastric, lung, bladder, colorectal, nasopharyngeal, esophageal, hepatocellular, thyroid and skin cancer. In addition, the aberrant expressions of FOXD2-AS1 have shown to contribute to proliferation, migration and invasion of cancer cells, and its deregulation is related to carcinogensis, overall survival, disease free survival, prognosis and tumor progression.

CONCLUSIONS

LncRNA FOXD2-AS1 is an oncogene and probably represents a feasible biomarker or therapeutic target in human cancers.

LncRNA FOXD2-AS1 Functions as a Competing Endogenous RNA to Regulate TERT Expression by Sponging miR-7-5p in Thyroid Cancer

Long non-coding RNA FOXD2 Adjacent Opposite Strand RNA 1 (FOXD2-AS1) has been widely reported to be implicated in the progression and recurrence of several cancers. The clinical significance and functional role of FOXD2-AS1 in thyroid carcinoma remain unknown. FOXD2-AS1 expression was evaluated by analyzing thyroid cancer RNA sequencing dataset from The Cancer Genome Atlas (TCGA). In vitro and in vivo assays were performed to assess the biological roles of FOXD2-AS1 in thyroid cancer cells. Western blot, luciferase, immunoprecipitation (IP), and RNA immunoprecipitation (RIP) assays were used to identify the underlying miRNA and mRNA target mediating the biological roles of FOXD2-AS1 in thyroid cancer cells. FOXD2-AS1 was upregulated in thyroid carcinoma tissues and cells. High expression of FOXD2-AS1 significantly correlated with clinical stage, recurrence of thyroid carcinoma. Silencing FOXD2-AS1 inhibited cancer stem cell-like phenotypes and attenuates the anoikis resistance in vitro. Downregulating FOXD2-AS1 represses the tumorigenesis of thyroid carcinoma cells in vivo. FOXD2-AS1 acts as a competitive endogenous RNA (ceRNA) for miR-7-5p, up-regulating the expression of telomerase reverse transcriptase (TERT), which further promotes the cancer stem cells features and anoikis resistance in thyroid cancer cells. Our findings indicate that FOXD2-AS1 functions as an oncogenic regulator in the development of thyroid cancer, contributing to early recurrence of thyroid cancer.

A Linkage Between Thyroid and Breast Cancer: A Common Etiology?

Breast and thyroid cancers are two malignancies with highest incidence in women. These cancers often occur metachronously. Women with thyroid cancer are at increased risk for subsequent breast cancer; women with breast cancer have an increased incidence of later development of thyroid cancer, suggesting a common etiology. This bidirectional relationship is reported worldwide; however, the underlying reasons for this co-occurrence are unknown. In this review, we summarize the current epidemiologic evidence and putative mechanisms of these metachronous or synchronous cancers. Key potential causative factors are chemotherapy and radiotherapy of the primary tumor, genetic variants linking the two diseases, hormonal signaling both from the thyroid gland and from estrogens, and lifestyle and environmental factors. There is a critical need for additional epidemiologic studies focused on gender and regional incidence together with molecular investigations on common tumorigenic pathways in these endocrine cancers. Understanding the putative mechanisms will aid in the diagnosis and clinical management of both diseases.

Identification of differential expressed lncRNAs in human thyroid cancer by a genome-wide analyses

Recently, a growing number of evidence has revealed that long noncoding RNAs (lncRNAs) act as key regulators in various cellular biologic processes, and dysregulation of lncRNAs involves in tumorigenesis and cancer progression. However, the expression pattern, clinical relevance, and biologic function of most lncRNAs in human thyroid cancer remain unclear. To identify more thyroid-cancer-associated lncRNAs, we analyzed the expression profile of lncRNAs in thyroid cancer tissues and adjacent normal or non-tumor tissues using RNA sequencing data and gene microarray data from The Cancer Genome Atlas and Gene Expression Omnibus. Annotation and analyses of these data revealed that hundreds of lncRNAs are differentially expressed in thyroid cancer tissues when compared with normal tissues. By copy number variation analyses, we identified that some of those dysregulated lncRNAs genome locus are accompanied with the copy number amplification or deletion. Moreover, some lncRNAs expression levels are significantly associated with thyroid cancer patients overall or recurrence-free survival time, such as RUNDC3A-AS1, FOXD2-AS1, PAX8-AS1, and CRYM-AS1. Furthermore, we validated an lncRNA termed LINC00704 in thyroid cancer cells by performing loss of function assays. Downregulation of LINC00704 could significantly impair thyroid cancer cells proliferation, colony formation, inhibit cell-cycle progression and cell invasion, and induce cell apoptosis. Taken together, our findings reveal that lots of lncRNAs are dysregulated and may play critical roles in thyroid cancer, and this study could provide useful resource for identification and investigation of novel lncRNA candidates for thyroid cancer.