LncRNA XIST/miR-34a axis modulates the cell proliferation and tumor growth of thyroid cancer through MET-PI3K-AKT signaling

LncRNA XIST promotes carboplatin resistance of ovarian cancer through activating autophagy via targeting miR-506-3p/FOXP1 axis

Objective

Resistance to chemotherapy drugs makes ovarian cancer (OC) difficult to treat and ultimately kills patients. Long non-coding RNAs are closely related to carboplatin resistance in OC. In present study, we explored the role of lncRNA X-inactive specific transcript (XIST) on carboplatin resistance in OC.

Methods

Cell viability, proliferation, and apoptosis were assessed through 2,5-diphenyl-2H-tetrazolium bromide, colony formation, and flow cytometry assays, respectively. Microtubule-associated protein 1A/1B-light chain 3 expression was evaluated by immunofluorescence assay to analyze the cell autophagy. The interaction of XIST/miR-506-3p or miR-506-3p/forkhead box protein P1 (FOXP1) was analyzed using RNA immunoprecipitation (RIP) and dual-luciferases reporter assays. The function of XIST/miR-506-3p/FOXP1 axis in vivo was further confirmed by tumor xenograft study and immunohistochemistry.

Results

The expression of XIST and FOXP1 increased while miR-506-3p decreased in OC and carboplatin resistance cells. XIST silencing repressed the proliferative and autophagic capacities of carboplatin resistance cells while promoted the apoptosis. XIST overexpression led to the opposite results. XIST targeted miR-506-3p and downregulated its expression. MiR-506-3p inhibition facilitated the proliferative and autophagic capacities while suppressed the apoptosis of cells, XIST knockdown reversed these effects. MiR-506-3p bound to FOXP1. XIST knockdown or miR-506-3p overexpression reversed the increase of cell proliferative and autophagic abilities and the decrease of apoptosis rate induced by FOXP1 overexpression. XIST affected autophagy and carboplatin resistance in vivo via regulating the miR-506-3p/FOXP1 axis.

Conclusion

XIST knockdown inhibited autophagy and carboplatin resistance of OC through FOXP1/protein kinase B (AKT)/mammalian target of rapamycin pathway by targeting miR-506-3p.

Knockdown of XIST inhibited autophagy induced by carboplatin and resistance to carboplatin in ovarian cells. XIST targeted miR-506-3p and reduced its expression. FOXP1 could be a target gene of miR-506-3p. XIST facilitated the autophagy and carboplatin resistance through miR-506-3p/FOXP1 axis in ovarian cancer.

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.

microRNA-20b-5p overexpression combing Pembrolizumab potentiates cancer cells to radiation therapy via repressing programmed death-ligand 1

Radiation therapy (RT) is widely applied in cancer treatment. The sensitivity of tumor cells to RT is the key to the treatment. This study probes the role and mechanism of miR-20b-5p in Pembrolizumab’s affecting the radiosensitivity of tumor cells. After Pembrolizumab treatment or cell transfection (miR-20b-5p mimics and miR-20b-5p inhibitors), tumor cells (NCI-H460 and ZR-75-30) were exposed to RT. The sensitivity of NCI-H460 and ZR-75-30 to RT was evaluated by monitoring cell proliferation and apoptosis. The dual-luciferase reporter assay and RNA immunoprecipitation (RIP) were adopted to evaluate the binding relationship between miR-20b-5p and CD274 (PD-L1). The xenograft model was established in nude mice to examine the mechanism of action of Pembrolizumab in vivo. Our outcomes exhibited that either Pembrolizumab treatment or miR-20b-5p overexpression potentiated radiosensitivity of tumor cells. Overexpressing miR-20b-5p enhanced radiosensitization of Pembrolizumab in vivo and in vitro by targeting PD-L1 and inactivating PD-L1/PD1. Overall, miR-20b-5p overexpression combined with Pembrolizumab potentiated cancer cells’ sensitivity to RT by repressing PD-L1/PD1.Abbreviations Akt: serine/threonine kinase 1; cDNA: complementary DNA; CO₂: carbon dioxide; EDTA: Ethylene Diamine Tetraacetic Acid; ENCORI: The Encyclopedia of RNA Interactomes; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; IGF2BP2: insulin like growth factor 2 mRNA binding protein 2; IHC: Immunohistochemistry; LncRNA MALAT1: Long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1; miRNAs: MicroRNAs; Mt: Mutant type; MTT: 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide; NC: negative control; NR2F2: nuclear receptor subfamily 2 group F member 2; NSCLC: non-small cell lung cancer; OD: optical density; PBS: phosphate-buffered saline; PD-L1: Programmed death-ligand 1; PD-1: programmed death 1; PI3K: phosphatidylinositol 3-kinase; qRT-PCR: Quantitative reverse transcription-polymerase chain reaction; RIP: RNA immunoprecipitation; RIPA: Radio Immunoprecipitation Assay; RRM2: ribonucleotide reductase regulatory subunit M2; RT: Radiation therapy; U6: U6 small nuclear RNA; V: volume; WB: Western blot; Wt: wild type; x ± sd: mean ± standard deviation.

Long non-coding RNA XIST: a novel oncogene in multiple cancers

Long non-coding RNA (lncRNA) X-inactive specific transcript (XIST) is an important lncRNA derived from the XIST gene in mammals. XIST is abnormally expressed in numerous tumors, in most of which XIST functions as an oncogene. XIST is involved in multiple aspects of carcinogenesis, including tumor onset, progression, and prognosis. In our review, we collected and analyzed the recent studies on the impact of XIST in human tumor development. The multilevel molecular functions of XIST in human tumors are comprehensively reviewed to clarify the pathologic mechanisms and to offer a novel direction for further study.

CUL5-Mediated Visfatin (NAMPT) Degradation Blocks Endothelial Proliferation and Angiogenesis via the MAPK/PI3K-AKT Signaling

ABSTRACT

Endothelial dysfunction participates in the pathogenesis of various cardiovascular disorders, and dysregulated angiogenesis involves the vascular endothelial growth factor (VEGF)-matrix metalloproteinases (MMP) system. Nicotinamide phosphoribosyltransferase (NAMPT) is known to enhance endothelial function and angiogenesis. The study found that NAMPT overexpression protected human coronary artery endothelial cells (HCAECs) from H2O2-induced injury through promoting cell viability, inhibiting cell apoptosis, enhancing cell motility, and promoting tube formation. Through analyses based on 2 Protein-Protein Interaction databases, Mentha and BioGrid, we identified CUL5 as a protein that may interact with NAMPT, which was then validated by Co-IP experiments. Through interacting with NAMPT, CUL5 inhibited NAMPT expression. In contrast to NAMPT, CUL5 overexpression further aggravated H2O2-induced HCAEC dysfunction. In the meantime, CUL5 overexpression reduced, whereas NAMPT overexpression increased the phosphorylation of p38 and Akt and the protein levels of VEGF and MMP2. More importantly, NAMPT overexpression partially reversed the effects of CUL5 overexpression on H2O2-stimulated HCAECs and the MAPK/phosphatidylinositol 3-kinase-Akt/VEGF/MMP signaling. In conclusion, CUL5 interacts with NAMPT in H2O2-stimulated HCAECs, suppressing cell viability, promoting cell apoptosis, and inhibiting cell mobility and tube formation. NAMPT overexpression protects against H2O2-induced HCAEC dysfunction by promoting cell viability, inhibiting cell apoptosis, and enhancing cell mobility and tube formation.

Lnc00892 competes with c-Jun to block NCL transcription, reducing the stability of RhoA/RhoC mRNA and impairing bladder cancer invasion

Metastasis of bladder cancer is a complex process and has been associated with poor clinical outcomes. However, the mechanisms of bladder cancer metastasis remain largely unknown. The present study found that the long noncoding RNA lnc00892 was significantly downregulated in bladder cancer tissues, with low lnc00892 expression associated with poor prognosis of bladder cancer patients. Lnc00892 significantly inhibited the migration, invasion, and metastasis of bladder cancer cells in vitro and in vivo. In-depth analysis showed that RhoA/C acted downstream of lnc00892 to inhibit bladder cancer metastasis. Mechanistically, lnc00892 reduces nucleolin gene transcription by competitively binding the promoter of nucleolin with c-Jun, thereby inhibiting nucleolin-mediated stabilization of RhoA/RhoC mRNA. Taken together, these findings provide novel insights into understanding the mechanisms of bladder cancer metastasis and suggest that lnc00892 can serve as a potential therapeutic target in patients with invasive bladder cancer.

miR-223 Enhances the Neuroprotection of Estradiol Against Oxidative Stress Injury by Inhibiting the FOXO3/TXNIP Axis

Alzheimer's disease (AD) is an irreversible neurodegenerative disorder characterized by complex pathogenesis, of which oxidative stress has long been regarded as a major mechanism. Previously, the protective effects of estradiol on SH-SY5Y cells against Aβ42-induced injuries were demonstrated. In this study, the protection of SH-SY5Y cells by estradiol from H₂O₂-caused oxidative stress injury and Alzheimer's mice was further confirmed. H₂O₂ downregulated, whereas estradiol upregulated miR-223 expression. miR-223 overexpression promoted cell viability, inhibited cell apoptosis, reduced ROS levels, enhanced Superoxide Dismutase (SOD) activity, and decreased malondialdehyde (MDA) content. However, miR-223 inhibition exerted opposite effects. miR-223 directly targeted forkhead box O3 (FOXO3) and inhibited FOXO3 expression. H₂O₂ increased, whereas estradiol decreased thioredoxin interacting protein (TXNIP) levels; FOXO3 positively regulated TXNIP protein levels. In SH-SY5Y cells, FOXO3 overexpression increased, whereas FOXO3 knockdown reduced the cell apoptosis and ROS levels. FOXO3 bound to TXNIP promoter region and activated TXNIP transcription, whereas the activation could be partially inhibited by estradiol. Collectively, the FOXO3/TXNIP axis is downstream of miR-223. miR-223 enhances the neuroprotection of estradiol against oxidative stress injury through the FOXO3/TXNIP axis.

Arecoline Enhances Phosphodiesterase 4A Activity to Promote Transforming Growth Factor-β-Induced Buccal Mucosal Fibroblast Activation via cAMP-Epac1 Signaling Pathway

Chewing areca nut (betel quid) is strongly associated with oral submucous fibrosis (OSF), a pre-cancerous lesion. Among the areca alkaloids, arecoline is the main agent responsible for fibroblast proliferation; however, the specific molecular mechanism of arecoline affecting the OSF remains unclear. The present study revealed that arecoline treatment significantly enhanced Transforming growth factor-β (TGF-β)-induced buccal mucosal fibroblast (BMF) activation and fibrotic changes. Arecoline interacts with phosphodiesterase 4A (PDE4A) to exert its effects through modulating PDE4A activity but not PDE4A expression. PDE4A silence reversed the effects of arecoline on TGF-β-induced BMFs activation and fibrotic changes. Moreover, the exchange protein directly activated by cAMP 1 (Epac1)-selective Cyclic adenosine 3′,5′-monophosphate (cAMP) analog (8-Me-cAMP) but not the protein kinase A (PKA)-selective cAMP analog (N6-cAMP) remarkably suppressed α-smooth muscle actin(α-SMA) and Collagen Type I Alpha 1 Chain (Col1A1) protein levels in response to TGF-β1 and arecoline co-treatment, indicating that cAMP-Epac1 but not cAMP-PKA signaling is involved in arecoline functions on TGF-β1-induced BMFs activation. In conclusion, arecoline promotes TGF-β1-induced BMFs activation through enhancing PDE4A activity and the cAMP-Epac1 signaling pathway during OSF. This novel mechanism might provide more powerful strategies for OSF treatment, requiring further in vivo and clinical investigation.

Effects of Cynaroside on Cell Proliferation, Apoptosis, Migration and Invasion though the MET/AKT/mTOR Axis in Gastric Cancer

The Chinese medicine monomer cynaroside (Cy) is a flavonoid glycoside compound that widely exists in plants and has a variety of pharmacological effects, such as its important role in the respiratory system, cardiovascular system and central nervous system. Studies have reported that Cy has varying degrees of anticancer activity in non-small cell lung cancer, cervical cancer, liver cancer, esophageal cancer and other cancers. However, there are no relevant reports about its role in gastric cancer. The MET/AKT/mTOR signaling pathway plays important roles in regulating various biological processes, including cell proliferation, apoptosis, autophagy, invasion and tumorigenesis. In this study, we confirmed that Cy can inhibit the cell growth, migration and invasion and tumorigenesis in gastric cancer. Our finding shows that Cy can block the MET/AKT/mTOR axis by decreasing the phosphorylation level of AKT, mTOR and P70S6K. Therefore, the MET/AKT/mTOR axis may be an important target for Cy. In summary, Cy has anti-cancer properties and is expected to be a potential drug for the treatment of gastric cancer.

Long non-coding RNA KRT8P41/miR-193a-3p/FUBP1 axis modulates the proliferation and invasion of chordoma cells

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lncRNA KRT8P41 potentially serves as an oncogenic lncRNA in chordoma.

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miR-193a binds to lncRNA KRT8P41 and FUBP1 3′UTR.

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LncRNA KRT8P41/miR-193a axis modulates chordoma cell aggressiveness through FUBP1.

Chordomas are low-grade malignancies accounting for 1–4% of primary bone malignancies. Moreover, local recurrences increase the rate of metastasis. Our previous study identified the far upstream element (FUSE)-binding protein 1 (FUBP1) as a biomarker and potential therapeutic target for chordoma. In this study, lncRNA KRT8P41 was identified as a lncRNA positively correlated with FUBP1. In chordoma patients, higher lncRNA KRT8P41 expression was correlated with a poorer prognosis. LncRNA KRT8P41 silencing significantly inhibited chordoma cell proliferation and invasion. miR-193a was negatively correlated with lncRNA KRT8P41 and FUBP1; lncRNA KRT8P41 inhibited miR-193a expression, and miR-193a inhibited FUBP1 expression. Furthermore, miR-193a directly bound to lncRNA KRT8P41 and FUBP1 and lncRNA KRT8P41 competed with FUBP1 for miR-193a binding and relieved miR-193a-mediated FUBP1 inhibition. LncRNA KRT8P41 silencing inhibited, whereas miR-193a inhibition promoted chordoma cell proliferation and invasion; the inhibition of miR-193a attenuated the roles of lncRNA KRT8P41. Within chordoma tissues, the expression of miR-193a was decreased, and the expression of FUBP1 increased compared to normal control tissues. LncRNA KRT8P41 exhibited a positive correlation with FUBP1 and a negative correlation with miR-193a in vivo. Therefore, it was concluded that lncRNA KRT8P41, miR-193a-3p, and FUBP1 form a lncRNA-miRNA-mRNA axis, modulating the proliferation and invasion of chordoma cells.

Systematic Analysis and Identification of Dysregulated Panel lncRNAs Contributing to Poor Prognosis in Head-Neck Cancer

Head and neck cancer (HNC) is one of the most prevalent cancers worldwide, accounting for approximately 5% of all cancers. While the underlying molecules and their pathogenetic mechanisms in HNC have yet to be well elucidated, recent studies have shown that dysregulation of lncRNAs may disrupt the homeostasis of various biological pathways. However, the understanding of lncRNAs in HNC is still limited by the lack of expression profiling. In the present study, we employed a systematic strategy to identify a panel of lncRNA associated with HNC. A cancer-related lncRNA profile PCR array was screened to explore potential molecules specific for HNC. A total of 55 lncRNAs were found to be dysregulated in HNC cells when compared to normal keratinocytes. Further analysis of the prognostic significance using The Cancer Genome Atlas (TCGA) database revealed 15 lncRNAs highly correlated with overall survival in HNC patients. Additionally, clinical sample expression analysis of the TCGA-HNSC cohort revealed 16 highly dysregulated lncRNAs in HNC, resulting in a combined 31-lncRNA signature panel that could predict prognosis. Validation of these molecules confirmed the considerable level of altered expressions in HNC cells, with XIST, HOXA11-AS, TSIX, MALAT1, WT1-AS, and IPW being the most prominently dysregulated. We further selected a molecule from our panel (XIST) to confirm the validity of these lncRNAs in the regulation of cancer aggressiveness. Gene ontology (GO) and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway enrichment analyses demonstrated that XIST participated in various cancer-related functions, including cell proliferation and metastasis. XIST silencing with the RNAi technique substantially reduced invasion and migration in several HNC cell lines. Thus, our study defined a 31-lncRNA panel as prognostic signatures in HNC. These perspective results provide a knowledge foundation for further application of these molecules in precision medicine.

Noncoding RNAs link metabolic reprogramming to immune microenvironment in cancers

Altered metabolic patterns in tumor cells not only meet their own growth requirements but also shape an immunosuppressive microenvironment through multiple mechanisms. Noncoding RNAs constitute approximately 60% of the transcriptional output of human cells and have been shown to regulate numerous cellular processes under developmental and pathological conditions. Given their extensive action mechanisms based on motif recognition patterns, noncoding RNAs may serve as hinges bridging metabolic activity and immune responses. Indeed, recent studies have shown that microRNAs, long noncoding RNAs and circRNAs are widely involved in tumor metabolic rewiring, immune cell infiltration and function. Hence, we summarized existing knowledge of the role of noncoding RNAs in the remodeling of tumor metabolism and the immune microenvironment, and notably, we established the TIMELnc manual, which is a free and public manual for researchers to identify pivotal lncRNAs that are simultaneously correlated with tumor metabolism and immune cell infiltration based on a bioinformatic approach.

Long non-coding RNA HLA complex group 18 promotes gastric cancer progression by targeting microRNA-370-3p expression

OBJECTIVES

Our research was aimed at investigating the biological character of human leukocyte antigen complex group 18 (HCG18) on gastric cancer (GC) progression and its potential mechanisms.

METHODS

The expression characteristics and prognostic values of HCG18 in GC were evaluated through the GEPIA database and Kaplan-Meier plotter database. Quantitative real-time PCR and Western blot were used for quantification of messenger RNA expression, microRNA (miRNA) expression and protein expression. Cell proliferation, migration and invasion were detected by cell counting kit-8 assay, 5'-bromo-2'-deoxyuridine assay and Transwell assay, respectively. Dual-luciferase reporter gene assay and RNA immunoprecipitation assay were used for examination of the interactions among HCG18, miR-370-3p and epidermal growth factor receptor (EGFR) 3'UTR.

KEY FINDINGS

HCG18 expression was up-regulated in GC tissues, and its high expression was closely associated with increased tumour size, advanced TNM stage, poor differentiation of tumour tissues and unfavourable prognosis of patients with GC. Additionally, HCG18 overexpression promoted the proliferation, migration and invasion of GC cells, and its knockdown suppressed the malignant phenotypes of GC cells. Furthermore, HCG18 served as a miRNA sponge to repress miR-370-3p and indirectly up-regulated EGFR expression in GC cells.

CONCLUSIONS

HCG18 served as a tumour-promoting factor in GC progression by modulating the miR-370-3p/EGFR axis.

miR-506-3p regulates TGF- 1 and affects dermal fibroblast proliferation, migration and collagen formation after thermal injury

Dermal fibroblasts are a promising candidate for cellular-based therapies for thermal wound healing because of their capacity of producing extracellular matrix (ECM), promoting wound contraction and the synthesis of type I collagen, and secreting growth factors. miRNAs (MicroRNAs) might mediate the role of TGF-β1(Transforming Growth Factor-beta 1), one of the major profibrotic cytokines, in improving thermal injury repair. In the present study, we observed the abnormal downregulation of TGF-β1 following thermal injury in the burnt dermis (in vivo) and heat-stimulated human dermal fibroblasts (in vitro). TGF-β1 overexpression reversed heat stimulation-induced repression on fibroblast viability, migration, and ECM synthesis. As demonstrated by online tool prediction and experimental analysis, miR-506-3p downregulated TGF-β1 levels via directly targeting TGFB1. In heat-stimulated human dermal fibroblasts, miR-506-3p expression showed to be significantly upregulated. miR-506-3p inhibition also reversed heat stimulation-induced repression on fibroblast viability, migration, and ECM synthesis; more importantly, TGF-β1 silencing aggravated the thermal injury in vitro and significantly reversed the effects of miR-506-3p inhibition on heat-stimulated dermal fibroblasts. In conclusion, miR-506-3p and its downstream target TGF-β1 form a regulatory axis, modulating the cell viability, migration, and ECM synthesis in human dermal fibroblasts following burn injury.

Using BioPAX-Parser (BiP) to enrich lists of genes or proteins with pathway data

BACKGROUND

Pathway enrichment analysis (PEA) is a well-established methodology for interpreting a list of genes and proteins of interest related to a condition under investigation. This paper aims to extend our previous work in which we introduced a preliminary comparative analysis of pathway enrichment analysis tools. We extended the earlier work by providing more case studies, comparing BiP enrichment performance with other well-known PEA software tools.

METHODS

PEA uses pathway information to discover connections between a list of genes and proteins as well as biological mechanisms, helping researchers to overcome the problem of explaining biological entity lists of interest disconnected from the biological context.

RESULTS

We compared the results of BiP with some existing pathway enrichment analysis tools comprising Centrality-based Pathway Enrichment, pathDIP, and Signaling Pathway Impact Analysis, considering three cancer types (colorectal, endometrial, and thyroid), for a total of six datasets (that is, two datasets per cancer type) obtained from the The Cancer Genome Atlas and Gene Expression Omnibus databases. We measured the similarities between the overlap of the enrichment results obtained using each couple of cancer datasets related to the same cancer.

CONCLUSION

As a result, BiP identified some well-known pathways related to the investigated cancer type, validated by the available literature. We also used the Jaccard and meet-min indices to evaluate the stability and the similarity between the enrichment results obtained from each couple of cancer datasets. The obtained results show that BiP provides more stable enrichment results than other tools.

Identification of Prognosis-Associated Biomarkers in Thyroid Carcinoma by a Bioinformatics Analysis

Background

This study aimed to identify the key genes associated with prognosis in thyroid cancer (TC), and to explore potential pathways.

Methods

GSE66783, GSE58545, and GSE129562 datasets were used to identify differentially expressed genes (DEGs) between tumor and normal tissues, followed by KEGG analyses on DEGs. The protein-protein interaction (PPI) network of DEGs was subsequently constructed to find the top 10 hub genes and seed genes in the whole network. Furthermore, the mRNA expressions of hub genes and prognostic values were explored. Regarding the seed gene, pathway activity score and GSEA analyses were conducted as well.

Results

1) A total of 183 DEGs were consistently expressed in three datasets comprising 76 up-regulated and 107 down-regulated genes. DEGs were mainly enriched in the p53 signaling pathway, complement and coagulation cascades, and hedgehog signaling pathway. 2) The top 10 hub genes, including CCND1, TIMP1, ICAM1, MET, PLAU, LDLR, PLAUR, ITGA2, ITGA3, and LGALS3, were identified. All hub genes were highly expressed in TC compared with normal samples. 3) High expression of CCND1, TIMP1, MET, and LGALS3 statistically correlated with a favorable prognosis of patients. Poor survival was observed in patients with ITGA2 and ITGA3 high expression. There was no association between ICAM1, PLAU, and PLAUR expression and survival of patients. LGALS3 and TIMP1 were further identified as independent prognostic factors in TC. 4) Among 10 hub genes, TIMP1 was determined as the seed gene, indicating its significance in the whole network. We further found that in most of the famous cancer-related pathways, TIMP1 higher expression caused a lower pathway activity, suggesting its inhibitory effect to these pathways in TC. In addition, TIMP1 positively correlated with the p53 signaling pathway, complement, and coagulation cascades involved in TC.

Conclusion

The present study provided seven prognosis-associated genes in TC and revealed several significant pathways, which contributed to elucidate the pathogenesis of TC.

Significance of DMBT1 in Papillary Thyroid Carcinoma Concurrent With Hashimoto's Thyroiditis

Background

Papillary thyroid carcinoma (PTC) concurrent with Hashimoto’s thyroiditis (HT) was associated with a better clinical prognosis. This study aimed to investigate a potential mRNA gene that affects the development of PTC, which helps PTC concurrent with HT patients have a better prognosis.

Material/Methods

PTC data were obtained from The Cancer Genome Atlas (TCGA) database. And the validation data of tissue specimens were collected from Guangzhou First People’s Hospital. The thyroid tissue sections were hybridized with deleted in malignant brain tumor 1 (DMBT1) probes by situ hybridization. Survival rates were analyzed using Kaplan-Meier curves, and the log-rank test was used to compare group survival rates. Prognosis clinicopathological factors were analyzed by Cox regression. Gene Ontology (GO) and Kyoto Gene and Genomic Encyclopedia (KEGG) pathway enrichment analyses were performed using single-sample gene set enrichment analysis (ssGSEA). Finally, the correlation of deletion in DMBT1 expression with overall immune status, tumor purity, and human leukocyte antigen (HLA) gene expression profile was analyzed.

Results

HT was significantly associated with sex, tumor foci, extrathyroidal extension (ETE), residual tumor, and tumor stage (T stage). Moreover, PTC concurrent with HT had a lower risk of recurrence versus non-HT groups. A total of 136 differentially expressed mRNAs (DEMs) were identified between HT and non-HT groups. Among them, the expression level of DMBT1 in HT groups was statistically higher than that in non-HT groups. A significant association with ETE and recurrence was revealed in the high expression and the low expression of DMBT1. Furthermore, DMBT1 was an independent predictor of survival. The overall immune activity of high expression of DMBT1 was higher than that of the low-expression group.

Conclusions

The PTC patients with HT had better behavior features and prognosis than those with simple PTC. DMBT1 in PTC-HT patients was a potential possible factor that inhibits tumors. High expression of DMBT1 may improve PTC prognosis by immune-related pathways.

Integrated Bioinformatics Analysis of DNA Methylation Biomarkers in Thyroid Cancer Based on TCGA Database

Previous studies have reported a cluster of aberrant promoter methylation changes associated with silencing of tumor suppressor genes in thyroid cancer (TC), but these results of individual genes are far from enough. In this work, we aimed to investigate the onset and pattern of methylation changes during the progression of TC by informatics analysis. We downloaded the DNA methylation and RNA sequencing datasets from The Cancer Genome Atlas focusing on TC. Abnormally methylated differentially expressed genes (DEGs) were sorted and pathways were analyzed. The KEGG and GO were then used to perform enrichment and functional analysis of identified pathways and genes. Gene-drug interaction network and human protein atlas were applied to obtain feature DNA methylation biomarkers. In total, we identified 2170 methylation-driven DEGs, including 1054 hypermethylatedlow-expression DEGs and 1116 hypomethylated-high-expression DEGs at the screening step. Further analysis screened total of eight feature DNA methylation biomarkers (RXRG, MET, PDGFRA, FCGR3A, VEGFA, CSF1R, FCGR1A and C1QA). Pathway analysis showed that aberrantly methylated DEGs mainly associated with transcriptional misregulation in cancer, MAPK signaling, and intrinsic apoptotic signaling in TC. Taken together, we have identified novel aberrantly methylated genes and pathways linked to TC, which might serve as novel biomarkers for precision diagnosis and disease treatment.

The Emerging Landscapes of Long Noncoding RNA in Thyroid Carcinoma: Biological Functions and Clinical Significance

Thyroid carcinoma (TC) is one of the most prevalent primary endocrine tumors, and its incidence is steadily and gradually increasing worldwide. Accumulating evidence has revealed the critical functions of long noncoding RNAs (lncRNAs) in the tumorigenesis and development of TC. Many TC-associated lncRNAs have been documented to be implicated in TC malignant behaviors, including abnormal cell proliferation, enhanced stem cell properties and aggressiveness, and resistance to therapeutics, through interaction with proteins, DNA, or RNA or encoding small peptides. Therefore, further elucidating the lncRNA dysregulation sheds additional insights into TC tumorigenesis and progression and opens new avenues for the early diagnosis and clinical therapy of TC. In this review, we summarize the abnormal expression of lncRNA in TC and the fundamental characteristics in TC tumorigenesis and development. Additionally, we introduce the potential prognostic and therapeutic significance of lncRNAs in TC.

Upregulation of FTX expression is associated with a poor prognosis and contributes to the progression of thyroid cancer

The dysregulated expression of long non-coding RNA FTX transcript X inactive specific transcript regulator (FTX) has been reported to be involved in the tumorigenesis of multiple cancer types. However, to the best our knowledge, its function and clinical value in thyroid cancer remain unclear. The present study aimed to determine the potential role of FTX in the development and progression of thyroid cancer. Reverse transcription-quantitative PCR analysis revealed that the expression levels of FTX were upregulated in thyroid cancer tissues and cell lines compared with those in normal tissues and cell lines, respectively. Survival analysis demonstrated that patients with upregulated FTX expression had a lower survival rate. Functional experiments revealed that the knockdown of FTX inhibited proliferation, cell cycle progression, migration and invasion, and induced apoptosis in thyroid cancer cells, while FTX overexpression accelerated proliferation, migration and invasion, and alleviated apoptosis in thyroid cancer cells. In addition, FTX knockdown significantly inhibited tumor growth in vivo. Furthermore, in thyroid cancer cells, FTX was identified to positively regulate the expression levels of TGF-β1, which is known to play an important regulatory role in tumor metastasis. In conclusion, the findings of the present study suggested that FTX may accelerate thyroid cancer progression via regulation of cellular activities, including cell proliferation, migration, invasion and apoptosis. Thus, FTX may represent a potential biomarker for the diagnosis, treatment and prognosis of thyroid cancer.

Highly Expressed CYBRD1 Associated with Glioma Recurrence Regulates the Immune Response of Glioma Cells to Interferon

Invasiveness, resistance to treatment, and recurrence of gliomas are significant hurdles to successful treatment regimens. Data sets from Gene Expression Omnibus (GEO), CGGA-RNAseq, and The Cancer Genome Atlas Glioblastoma Multiforme (TCGA-GBM) were analyzed, and an increased expression of Cytochrome B Reductase 1 (CYBRD1) was identified and could be associated with aggravated clinical outcomes. Gene ontology (GO) enrichment analysis indicated that CYBRD1 co-expressed genes are enriched during an immune response. CYBRD1 overexpression in glioma cell lines is enhanced, whereas CYBRD1 silencing attenuated the aggressiveness of glioma cells. In IFN-α-treated glioma cells, IFN-α suppressed the viability and migratory ability and invasive ability of glioma cells, whereas CYBRD1 overexpression attenuated the antitumor effects of IFN-α. CYBRD1 could potentially serve as a biomarker for glioma recurrence. CYBRD1 overexpression enhances glioma cell aggressiveness and attenuates glioma cell response to IFN-α.

GLP-1-Induced AMPK Activation Inhibits PARP-1 and Promotes LXR-Mediated ABCA1 Expression to Protect Pancreatic β-Cells Against Cholesterol-Induced Toxicity Through Cholesterol Efflux

T2DM (Type 2 diabetes) is a complex, chronic disease characterized as insulin resistance and islet β-cell dysfunction. Bariatric surgeries such as Roux-en-Y gastric bypass (RYGB) surgery and laparoscopic sleeve gastrectomy (LSG) have become part of a critical treatment regimen in the treatment of obesity and T2DM. Moreover, GLP-1 increase following bariatric surgery has been regarded as a significant event in bariatric surgery-induced remission of T2DM. In this study, a high concentration cholesterol-induced lipotoxicity was observed in INS-1 cells, including inhibited cell viability and insulin secretion. Enhanced cell apoptosis and inhibited cholesterol efflux from INS-1 cells; meanwhile, ABCA1 protein level was decreased by cholesterol stimulation. Cholesterol-induced toxicity and ABCA1 downregulation were attenuated by GLP-1 agonist EX-4. GLP-1 induced AMPK phosphorylation during the protection against cholesterol-induced toxicity. Under cholesterol stimulation, GLP-1-induced AMPK activation inhibited PARP-1 activity, therefore attenuating cholesterol-induced toxicity in INS-1 cells. In INS-1 cells, PARP-1 directly interacted with LXR, leading to the poly(ADP-ribosyl)ation of LXRα and downregulation of LXR-mediated ABCA1 expression. In the STZ-induced T2DM model in rats, RYGB surgery or EX-4 treatment improved the glucose metabolism and lipid metabolism in rats through GLP-1 inhibition of PARP-1 activity. In conclusion, GLP-1 inhibits PARP-1 to protect islet β cell function against cholesterol-induced toxicity in vitro and in vivo through enhancing cholesterol efflux. GLP-1-induced AMPK and LXR-mediated ABCA1 expression are involved in GLP-1 protective effects.

Cucurbitacin B Inhibits Cell Proliferation by Regulating X-Inactive Specific Transcript Expression in Tongue Cancer

Cucurbitacin B (CuB), a natural product, has anti-tumor effects on various cancers. In order to investigate the expression of long non-coding RNAs (lncRNA), we carried out RNA sequencing (RNA-seq) and quantitative PCR (qPCR). The data indicated that CAL27 and SCC9 tongue squamous cell carcinoma (TSCC) cells had reduced expression of X-inactive specific transcript (XIST) after CuB treatment. Moreover, our results showed increased expression of XIST in human tongue cancer. In this study, CuB treatment inhibited proliferation, migration and invasion of SCC9 cells, and induced cellular apoptosis. Interestingly, knockdown of XIST led to inhibition of cell proliferation and induced apoptosis in vitro. In addition, reduced expression of XIST suppressed cell migration and invasion. MicroRNA 29b (miR-29b) was identified as a direct target of XIST. Previous reports indicated that miR-29b regulates p53 protein. Our results suggest that increased expression of miR-29b induces cell apoptosis through p53 protein. The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (CRISPR/Cas9) system validated the role of XIST knockout in tumor development in vivo. Together, these results suggest that CuB exerts significant anti-cancer activity by regulating expression of XIST via miR-29b.

Downregulation of lncRNA XIST promotes proliferation and differentiation, limits apoptosis of osteoblasts through regulating miR-203-3p/ZFPM2 axis

Background: Bone fracture is a common medical condition. Evidence suggested that long noncoding RNAs (lncRNAs) could regulate the bio-function in osteoblast. In this study, we explored the role and mechanism of lncRNA X-inactive specific transcript (XIST) on the proliferation, apoptosis, and differentiation of osteoblasts using MC3T3-E1 cells. Methods: Expression of XIST, microRNA-203-3p (miR-203-3p), and zinc finger protein multitype 2 (ZFPM2) was measured by quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability and apoptosis of MC3T3-E1 cells were measured using the Cell Counting Kit-8 (CCK-8) and the flow cytometry. Western blot was used to measure the expression of cell cycle-related proteins, apoptosis-related proteins, and ZFPM2. Levels of differentiation-related factors were measured by qRT-PCR, western blot, and alkaline phosphatase (ALP) kit. Target interaction between miR-203-3p and XIST or ZFPM2 was predicted through bioinformatics analysis and verified by dual-luciferase reporter, RNA immunoprecipitation (RIP) assay, or RNA pull-down assay. Results: The expression of XIST and ZFPM2 was increased while miR-203-3p was decreased in plasmas and MC3T3-E1 cells. Knockdown of XIST promoted the proliferation, differentiation, but limited apoptosis in MC3T3-E1 cells. . Mechanically, overexpression of XIST could reverse the bio-function of miR-203-3p transfection. Additionally, miR-203-3p inverted a series of bio-functional effects of ZFPM2. Furthermore, anti-miR-203-3p rescued si-XIST-induced downregulation of ZFPM2. Conclusion: Downregulation of lncRNA XIST promoted osteoblast proliferation and differentiation, but limited apoptosis by miR-203-3p/ZFPM2 axis.

X-Inactive-Specific Transcript: Review of Its Functions in the Carcinogenesis

X-inactive-specific transcript (XIST) is one of the firstly discovered long non-coding RNAs with prominent roles in the process of X inactivation. Moreover, this transcript contributes in the carcinogenic process in different tissues. In addition to interacting with chromatin modifying molecules, XIST can be served as a molecular sponge for miRNAs to modulate expression of miRNA targets. Most of the studies have indicated an oncogenic role for XIST. However, in prostate cancer, a single study has indicated a tumor suppressor role for this lncRNA. Similar result has been reported for XIST in oral squamous cell carcinoma. In hepatocellular carcinoma, breast cancer, ovarian cancer, osteosarcoma, and renal cell carcinoma, different studies have reported inconsistent results. In the present manuscript, we review function of XIST in the carcinogenesis.

Biological Function of Long Non-coding RNA (LncRNA) Xist

Long non-coding RNAs (lncRNAs) regulate gene expression in a variety of ways at epigenetic, chromatin remodeling, transcriptional, and translational levels. Accumulating evidence suggests that lncRNA X-inactive specific transcript (lncRNA Xist) serves as an important regulator of cell growth and development. Despites its original roles in X-chromosome dosage compensation, lncRNA Xist also participates in the development of tumor and other human diseases by functioning as a competing endogenous RNA (ceRNA). In this review, we comprehensively summarized recent progress in understanding the cellular functions of lncRNA Xist in mammalian cells and discussed current knowledge regarding the ceRNA network of lncRNA Xist in various diseases. Long non-coding RNAs (lncRNAs) are transcripts that are more than 200 nt in length and without an apparent protein-coding capacity (Furlan and Rougeulle, 2016; Maduro et al., 2016). These RNAs are believed to be transcribed by the approximately 98-99% non-coding regions of the human genome (Derrien et al., 2012; Fu, 2014; Montalbano et al., 2017; Slack and Chinnaiyan, 2019), as well as a large variety of genomic regions, such as exonic, tronic, and intergenic regions. Hence, lncRNAs are also divided into eight categories: Intergenic lncRNAs, Intronic lncRNAs, Enhancer lncRNAs, Promoter lncRNAs, Natural antisense/sense lncRNAs, Small nucleolar RNA-ended lncRNAs (sno-lncRNAs), Bidirectional lncRNAs, and non-poly(A) lncRNAs (Ma et al., 2013; Devaux et al., 2015; St Laurent et al., 2015; Chen, 2016; Quinn and Chang, 2016; Richard and Eichhorn, 2018; Connerty et al., 2020). A range of evidence has suggested that lncRNAs function as key regulators in crucial cellular functions, including proliferation, differentiation, apoptosis, migration, and invasion, by regulating the expression level of target genes via epigenomic, transcriptional, or post-transcriptional approaches (Cao et al., 2018). Moreover, lncRNAs detected in body fluids were also believed to serve as potential biomarkers for the diagnosis, prognosis, and monitoring of disease progression, and act as novel and potential drug targets for therapeutic exploitation in human disease (Jiang W. et al., 2018; Zhou et al., 2019a). Long non-coding RNA X-inactive specific transcript (lncRNA Xist) are a set of 15,000-20,000 nt sequences localized in the X chromosome inactivation center (XIC) of chromosome Xq13.2 (Brown et al., 1992; Debrand et al., 1998; Kay, 1998; Lee et al., 2013; da Rocha and Heard, 2017; Yang Z. et al., 2018; Brockdorff, 2019). Previous studies have indicated that lncRNA Xist regulate X chromosome inactivation (XCI), resulting in the inheritable silencing of one of the X-chromosomes during female cell development. Also, it serves a vital regulatory function in the whole spectrum of human disease (notably cancer) and can be used as a novel diagnostic and prognostic biomarker and as a potential therapeutic target for human disease in the clinic (Liu et al., 2018b; Deng et al., 2019; Dinescu et al., 2019; Mutzel and Schulz, 2020; Patrat et al., 2020; Wang et al., 2020a). In particular, lncRNA Xist have been demonstrated to be involved in the development of multiple types of tumors including brain tumor, Leukemia, lung cancer, breast cancer, and liver cancer, with the prominent examples outlined in Table 1. It was also believed that lncRNA Xist (Chaligne and Heard, 2014; Yang Z. et al., 2018) contributed to other diseases, such as pulmonary fibrosis, inflammation, neuropathic pain, cardiomyocyte hypertrophy, and osteoarthritis chondrocytes, and more specific details can be found in Table 2. This review summarizes the current knowledge on the regulatory mechanisms of lncRNA Xist on both chromosome dosage compensation and pathogenesis (especially cancer) processes, with a focus on the regulatory network of lncRNA Xist in human disease.

Inhibitor of apoptosis-stimulating p53 protein protects against inflammatory bowel disease in mice models by inhibiting the nuclear factor kappa B signaling

Drugs and therapies available for the treatment of inflammatory bowel disease (IBD) are not satisfactory. Our previous study has established the inhibitor of apoptosis-stimulating p53 protein (iASPP) as an oncogenic regulator in colorectal cancer by forming a regulatory axis or feedback loop with miR-124, p53, or p63. As iASPP could target and inhibit nuclear factor kappa B (NF-κB) activation, in this study the role and mechanism of iASPP in IBD was investigated. The aberrant up-regulation of iASPP in IBD was subsequently confirmed, based on online data sets, clinical sample examinations and 2,4,6-trinitrobenzene sulfonic acid (TNBS)- and dextran sulfate sodium (DSS)-induced colitis mice models. TNBS or DSS stimulation successfully induced colon shortness, body weight loss, mice colon oxidative stress and inflammation. In both types of colitis mice models, iASPP over-expression improved, whereas iASPP knockdown aggravated TNBS or DSS stimulation-caused colon shortness, body weight loss and mice colon oxidative stress and inflammation. Meanwhile, in both types of colitis mice models, iASPP over-expression inhibited p65 phosphorylation and decreased the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, C-X-C motif chemokine ligand (CXCL)1 and CXCL2 in mice colons, whereas iASPP knockdown exerted opposite effects.

LncRNA-NNT-AS1 contributes to the progression of glioma by miR-582-5p/EZH2 axis

Increasing studies have shown that long non-coding RNAs (lncRNAs) had crucial regulatory roles in many diseases. Nevertheless, the biological relevance and mechanisms of the NNT-AS1 in gliom remain poorly understood. In the present study, NNT-AS1 expression was up-regulated in the glioma cell lines. Functional assays demonstrated that depletion of NNT-AS1 could notably suppress the proliferation, migration, invasion and EMT of U87MG and A172 cells. In addition, miR-582-5p was predicted to be a target of NNT-AS1 and EZH2 was predicted to be a target of miR-582-5p by bioinformatics software, which was further confirmed by luciferase reporter assay. Additionally, results of recue assays proofed that NNT-AS1/miR-582-5p/EZH2 axis aggravated the malignant behaviors of glioma. Ultimately, our findings revealed that NNT-AS1 contributes to progression via targeting miR-582-5p/EZH2 axis, revealing NNT-AS1 as a latent effective target for the diagnosis and treatment of glioma patients.

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.

Targeting pyruvate dehydrogenase kinase signaling in the development of effective cancer therapy

Pyruvate is irreversibly decarboxylated to acetyl coenzyme A by mitochondrial pyruvate dehydrogenase complex (PDC). Decarboxylation of pyruvate is considered a crucial step in cell metabolism and energetics. The cancer cells prefer aerobic glycolysis rather than mitochondrial oxidation of pyruvate. This attribute of cancer cells allows them to sustain under indefinite proliferation and growth. Pyruvate dehydrogenase kinases (PDKs) play critical roles in many diseases because they regulate PDC activity. Recent findings suggest an altered metabolism of cancer cells is associated with impaired mitochondrial function due to PDC inhibition. PDKs inhibit the PDC activity via phosphorylation of the E1a subunit and subsequently cause a glycolytic shift. Thus, inhibition of PDK is an attractive strategy in anticancer therapy. This review highlights that PDC/PDK axis could be implicated in cancer's therapeutic management by developing potential small-molecule PDK inhibitors. In recent years, a dramatic increase in the targeting of the PDC/PDK axis for cancer treatment gained an attention from the scientific community. We further discuss breakthrough findings in the PDC-PDK axis. In addition, structural features, functional significance, mechanism of activation, involvement in various human pathologies, and expression of different forms of PDKs (PDK1-4) in different types of cancers are discussed in detail. We further emphasized the gene expression profiling of PDKs in cancer patients to prognosis and therapeutic manifestations. Additionally, inhibition of the PDK/PDC axis by small molecule inhibitors and natural compounds at different clinical evaluation stages has also been discussed comprehensively.

LncRNA SNHG16 Facilitates Nasopharyngeal Carcinoma Progression by Acting as ceRNA to Sponge miR-520a-3p and Upregulate MAPK1 Expression

Background

Accumulating evidence shows that lncRNAs are widely involved cellular processes of various tumors. The aim of this study was to explore the potential role and molecular mechanism of lncRNA SNHG16 in nasopharyngeal carcinoma (NPC).

Methods

SNHG16, miR-520a-3p, and MAPK1 levels were measured by RT-qPCR assay. CCK-8, colony formation, transwell, and flow cytometry assays were adopted to analyze the proliferation, migration, invasion, and apoptosis of NPC cell lines (SUNE1 and 5–8F). Murine xenograft model was used to investigate tumor growth and metastasis in vivo. Immunohistochemical staining was employed to evaluate the levels of Bcl-2, cleaved caspase-3, Bax, and Ki-67. Dual-luciferase reporter assays were conducted to analyze the binding ability between miR-520a-3p and SNHG16 or MAPK1.

Results

SNHG16 was overexpressed in NPC tissues and cells. High SNHG16 expression indicated a poor prognosis. SNHG16 knockdown could cause significant inhibition on cell proliferation and metastasis, induce cell apoptosis in NPC cells, and repressed tumor growth and metastasis in vivo. Additionally, SNHG16 could directly bind to miR-520a-3p, thus positively regulating MAPK1 expression. Moreover, functional analysis indicated that miR-520a-3p exerted a tumor-suppressing role in NPC progression. Rescue assays demonstrated that MAPK1 upregulation could abrogate the inhibitory effects on NPC cell proliferation and metastasis, as well as the promoting effects on NPC cell apoptosis caused by SNHG16 knockdown. In conclusion, SNHG16 contributed to the proliferation and metastasis of NPC cells by modulating the miR-520a-3p/MAPK1 axis.

Conclusion

These results suggest that SNHG16 acts as an oncogene in the progression of NPC via modulating the miR-520a-3p/MAPK1 axis.

STAT3/SH3PXD2A-AS1/miR-125b/STAT3 positive feedback loop affects psoriasis pathogenesis via regulating human keratinocyte proliferation

Psoriasis is a chronic immune-mediated inflammatory dermatosis. STAT3 has been considered a critical regulator of psoriasis pathogenesis due to its role in inflammation and immune responses. Furthermore, alongside non-coding RNAs, including long non-coding RNAs (lncRNAs) and miRNAs, STAT3 also plays a critical role in psoriasis pathogenesis. Two sets of online microarray profiles (GSE50790 and GSE13355) were subsequently downloaded and analyzed to search for lncRNAs upregulated in psoriasis lesion tissues. The expression of lncRNA SH3PXD2A-AS1 could be remarkably upregulated in psoriasis specimens. SH3PXD2A-AS1 silence was found to suppress HaCaT cell proliferation and promote HaCaT cell apoptosis significantly. Meanwhile, SH3PXD2A-AS1 silence significantly increased cleaved-caspase-3 protein levels and inhibited S100A7, TNF-α, IL-6, p-STAT3, STAT3, CyclinD1, and survivin protein levels. Moreover, the expression of miR-125b could be substantially decreased within psoriasis lesion tissue samples, while miR-125b could negatively regulate the SH3PXD2A-AS1 and STAT3 expression. As predicted by an online tool and validated by luciferase reporter and RIP assays, miR-125b was found to bind to SH3PXD2A-AS1 and STAT3 3'UTR directly; SH3PXD2A-AS1 competed with 3'UTR of STAT3 for miR-125b binding to counteract miR-125b-mediated suppression of STAT3. STAT3 is known to activate the transcription of SH3PXD2A-AS1 through the targeting of its promoter region. It consequentially forms a regulatory feedback loop promoting SH3PXD2A-AS1 expression affecting HaCat cell proliferation and apoptosis. A novel STAT3 related mechanism whereby STAT 3/ SH3PXD2A-AS1/ miR-125b/STAT3 positive feedback loop which could potentially affect the pathogenesis of Psoriasis has been established.

Establishment and analysis of the lncRNA-miRNA-mRNA network based on competitive endogenous RNA identifies functional genes in heart failure

Heart failure (HF), a common disease in adults, accounts for significantly global morbidity and mortality. Due to population aging, therapeutic progression in acute cardiovascular events, the prevalence of HF is increasing, in spite of the efficacy of multiple therapies for HF patients with decreased ejection fraction. Despite great progress in the underlying molecular mechanisms, it remains incompletely clear of the function of competing endogenous RNA (ceRNA) network in HF pathogenesis. Herein, we established an HF-related ceRNA network on the basis of differentially expressed long noncoding RNAs (lncRNAs), microRNAs (miRNAs) as well as mRNAs from GSE136547 and GSE124401 datasets. In brief, the ceRNA network composed of 58 mRNA nodes, 5 miRNA nodes, 82 lncRNA nodes as well as 252 edges. In addition, three lncRNAs (KCNQ1OT1, XIST and AC010336) with higher node degrees than other lncRNAs were chosen as hub nodes. At the same time, we have established five subnetwork of miR-17-5p, miR-20b-5p, miR-107, miR-125a-5p and miR-140-5p centered ceRNA. Pathway analysis revealed the enrichment of ceRNA network in cell cycle pathways. Collectively, our research sheds new lights on the essential functions of ceRNA network in HF development, which also suggests possible application of these hub nodes as diagnostic biomarkers as well as therapeutic targets.

The comprehensive landscape of miR-34a in cancer research

MicroRNA-34 (miR-34) plays central roles in human diseases, especially cancers. Inactivation of miR-34 is detected in cancer cell lines and tumor tissues versus normal controls, implying its potential tumor-suppressive effect. Clinically, miR-34 has been identified as promising prognostic indicators for various cancers. In fact, members of the miR-34 family, especially miR-34a, have been convincingly proved to affect almost the whole cancer progression process. Here, a total of 512 (miR-34a, 10/21), 85 (miR-34b, 10/16), and 114 (miR-34c, 10/14) putative targets of miR-34a/b/c are predicted by at least ten miRNA databases, respectively. These targets are further analyzed in gene ontology (GO), KEGG pathway, and the Reactome pathway dataset. The results suggest their involvement in the regulation of signal transduction, macromolecule metabolism, and protein modification. Also, the targets are implicated in critical signaling pathways, such as MAPK, Notch, Wnt, PI3K/AKT, p53, and Ras, as well as apoptosis, cell cycle, and EMT-related pathways. Moreover, the upstream regulators of miR-34a, mainly including transcription factors (TFs), lncRNAs, and DNA methylation, will be summarized. Meanwhile, the potential TF upstream of miR-34a/b/c will be predicted by PROMO, JASPAR, Animal TFDB 3.0, and GeneCard databases. Notably, miR-34a is an attractive target for certain cancers. In fact, miR-34a-based systemic delivery combined with chemotherapy or radiotherapy can more effectively control tumor progression. Collectively, this review will provide a panorama for miR-34a in cancer research.

AKAP2 overexpression modulates growth plate chondrocyte functions through ERK1/2 signaling

In our previous study, the mutation c.2645A > C (p. E882A) was found in the A-Kinase Anchoring Protein 2 (AKAP2) gene, which plays an important role in regulating the development of the skeletal system; however, the specific effect of AKAP2 on chondrocyte proliferation and differentiation and the potential mechanism are still not clear. In the present study, we investigated the effect of AKAP2 in vitro. We successfully isolated human growth plate chondrocytes (GPCs) from growth plate cartilage tissues and identified GPCs by aggrecan expression and flow cytometric analysis. AKAP2 overexpression significantly promoted GPC proliferation, enhanced GPC differentiation, and promoted extracellular matrix (ECM) synthesis, whereas AKAP2 silencing exerted the opposite effects on GPCs. AKAP2 overexpression increased, while AKAP2 silencing decreased, the protein levels of p-extracellular regulated protein kinases (ERK)1/2. More importantly, the promotive effects of AKAP2 overexpression on GPC proliferation, differentiation, and ECM synthesis were significantly reversed by the ERK1/2 signaling antagonist U0126, suggesting that AKAP2 enhances GPC functions through ERK1/2 signaling. In conclusion, we demonstrate AKAP2 overexpression-induced enhancement of GPC functions through ERK1/2 signaling. Considering the critical role of GPC functions in adolescent idiopathic scoliosis (AIS) pathogenesis, the application of AKAP2 targeting in AIS treatment should be investigated in future studies.

The VIM-AS1/miR-655/ZEB1 axis modulates bladder cancer cell metastasis by regulating epithelial-mesenchymal transition

BACKGROUND

Invasive bladder tumors cause a worse prognosis in patients and remain a clinical challenge. Epithelial-mesenchymal transition (EMT) is associated with bladder cancer metastasis. In the present research, we attempted to demonstrate a novel mechanism by which a long noncoding RNA (lncRNA)-miRNA-mRNA axis regulates EMT and metastasis in bladder cancer.

METHODS

Immunofluorescence (IF) staining was used to detect Vimentin expression. The protein expression of ZEB1, Vimentin, E-cadherin, and Snail was investigated by using immunoblotting assays. Transwell assays were performed to detect the invasive capacity of bladder cancer cells. A wound healing assay was used to measure the migratory capacity of bladder cancer cells.

RESULTS

Herein, we identified lncRNA VIM-AS1 as a highly- expressed lncRNA in bladder cancer, especially in metastatic bladder cancer tissues and high-metastatic bladder cancer cell lines. By acting as a ceRNA for miR-655, VIM-AS1 competed with ZEB1 for miR-655 binding, therefore eliminating the miR-655-mediated suppression of ZEB1, finally promoting EMT in both high- and low-metastatic bladder cancer cells and enhancing cancer cell metastasis.

CONCLUSIONS

In conclusion, the VIM-AS1/miR-655/ZEB1 axis might be a promising target for improving bladder cancer metastasis via an EMT-related mechanism.

Long Noncoding RNA MLK7-AS1 Promotes Non-Small-Cell Lung Cancer Migration and Invasion via the miR-375-3p/YWHAZ Axis

Long noncoding RNAs act essential regulators in lung cancer tumorigenesis. Our research aimed to investigate the potential function and molecular mechanisms of MLK7-AS1 in NSCLC (non-small-cell lung cancer). QRT-PCR results indicated that the MLK7-AS1 expression level was upregulated in NSCLC cells and tissues. MLK7-AS1 strengthened cell migration and invasion in H1299 and A549 cells. Luciferase reporter assay found that MLK7-AS1 functioned as an endogenous sponge for miR-375-3p. Transwell assay results showed that miR-375-3p suppressed cell migration and invasion in H1299 and A549 cells. YWHAZ was confirmed as a target gene of miR-375-3p by Targetscan. YWHAZ overexpression promoted the invasion of H1299 and A549 cells. MLK7-AS1 upregulated YWHAZ expression and enhanced H1299 and A549 cell invasion by sponging miR-375-3p. MLK7-AS1 improved the metastasis ability of A549 in vivo. In conclusion, MLK7-AS1 was identified as a novel oncogenic RNA in NSCLC and can function as a potential therapeutic target for NSCLC treatment.

ZFPM2-AS1 transcriptionally mediated by STAT1 regulates thyroid cancer cell growth, migration and invasion via miR-515-5p/TUSC3

Objective: Our purpose was to study the roles and molecular mechanisms of long non-coding RNA (lncRNA) ZFPM2 Antisense RNA 1 (ZFPM2-AS1) in thyroid cancer.

Methods: Firstly, the expression of ZFPM2-AS1, miR-515-5p and TUSC3 was detected in thyroid cancer tissues and cells. Secondary, their biological functions (proliferation, apoptosis, migration and invasion) were analyzed by a serious of functional experiments including cell counting kit-8 (CCK-8), clone formation, 5-Ethynyl-2'-deoxyuridine (EdU), enzyme-linked immunosorbent assay (ELISA), wound healing and Transwell assays. Thirdly, the mechanisms of STAT1/ZFPM2-AS1 and ZFPM2-AS1/miR-515-5p/TUSC were validated using chromatin immunoprecipitation (CHIP), pull-down and luciferase reporter assays.

Results: ZFPM2-AS1 and TUSC were both highly expressed and miR-515-5p was down-regulated in thyroid cancer tissues as well as cells. Their knockdown weakened thyroid cancer cell growth, migration, and invasion. ZFPM2-AS1 was mainly distributed in the nucleus and cytoplasm of thyroid cancer cells. Mechanistically, up-regulation of ZFPM2-AS1 was induced by transcription factor STAT1 in line with CHIP and luciferase reporter assays. Furthermore, as a sponge of miR-515-5p, ZFPM2-AS1 decreased the ability of miR-515-5p to inhibit TUSC3 expression by pull-down, luciferase reporter and gain-and-loss assays, thereby promoting malignant progression of thyroid cancer.

Conclusion: ZFPM2-AS1 acted as an oncogene in thyroid cancer, which was transcriptionally mediated by STAT1. Furthermore, ZFPM2-AS1 weakened the inhibitory effect of miR-515-5p on TUSC3. Thus, ZFPM2-AS1 could be an underlying biomarker for thyroid cancer.

Expression level of long non-coding RNA colon adenocarcinoma hypermethylated serves as a novel prognostic biomarker in patients with thyroid carcinoma

The present study attempts to identify the prognostic value and potential mechanism of action of colorectal adenocarcinoma hypermethylated (CAHM) in thyroid carcinoma (THCA) by using the RNA sequencing (RNA-seq) dataset from The Cancer Genome Atlas (TCGA). The functional mechanism of CAHM was explored by using RNA-seq dataset and multiple functional enrichment analysis approaches. Connectivity map (CMap) online analysis tool was also used to predict CAHM targeted drugs. Survival analysis suggests that THCA patients with high CAHM expression have lower risk of death than the low CAHM expression (log-rank P=0.022, adjusted P=0.011, HR = 0.187, 95% confidence interval (CI) = 0.051–0.685). Functional enrichment of CAHM co-expression genes suggests that CAHM may play a role in the following biological processes: DNA repair, cell adhesion, DNA replication, vascular endothelial growth factor receptor, Erb-B2 receptor tyrosine kinase 2, ErbB and thyroid hormone signaling pathways. Functional enrichment of differentially expressed genes (DEGs) between low- and high-CAHM phenotype suggests that different CAHM expression levels may have the following differences in biological processes in THCA: cell adhesion, cell proliferation, extracellular signal-regulated kinase (ERK) 1 (ERK1) and ERK2 cascade, G-protein coupled receptor, chemokine and phosphatidylinositol-3-kinase-Akt signaling pathways. Connectivity map have identified five drugs (levobunolol, NU-1025, quipazine, anisomycin and sulfathiazole) for CAHM targeted therapy in THCA. Gene set enrichment analysis (GSEA) suggest that low CAHM phenotype were notably enriched in p53, nuclear factor κB, Janus kinase-signal transducer and activators of transcription, tumor necrosis factor, epidermal growth factor receptor and other signaling pathways. In the present study, we have identified that CAHM may serve as novel prognostic biomarkers for predicting overall survival (OS) in patients with THCA.

Atorvastatin improves the proliferation and migration of endothelial progenitor cells via the miR-221/VEGFA axis

The present study was aimed at investigating the detailed functions of atorvastatin, a lipid-lowering agent, in the pathogenesis of coronary slow flow (CSF), a clinical disease characterized by delayed angiographic coronary opacity without obstructive coronary disease. In the present study, we successfully identified isolated endothelial progenitor cells (EPCs) from the peripheral blood of patients with CSF. Their vascular endothelial growth factor-A (VEGFA) protein levels were determined using immunoblotting analyses. We determined cell viability using MTT assays, cell migration capacity using Transwell assays, and the angiogenic capacity using a tube formation assay. The target association between miR-221 and VEGFA was validated with a luciferase reporter assay. Atorvastatin treatment increased EPC VEGFA protein levels, proliferation, migration, and angiogenesis. miR-221 expression was down-regulated after atorvastatin treatment; miR-221 overexpression exerted an opposing effect to atorvastatin treatment on VEGFA protein, EPC proliferation, migration, and angiogenesis. The protective effects of atorvastatin treatment on VEGFA protein and EPCs could be significantly suppressed by miR-221 overexpression. miR-221 directly bound the VEGFA 3'UTR to inhibit its expression. In conclusion, atorvastatin improves the cell proliferation, migration, and angiogenesis of EPCs via the miR-221/VEGFA axis. Thus, atorvastatin could be a potent agent against CSF, pending further in vivo and clinical investigations.

Long non‑coding RNA KCNQ1OT1 promotes nasopharyngeal carcinoma cell cisplatin resistance via the miR‑454/USP47 axis

Long non‑coding RNAs serve an essential role in drug resistance in various types of cancer, including lung, breast and bladder cancer. The present study aimed to investigate whether KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1) was associated with cisplatin (DDP) resistance in nasopharyngeal carcinoma (NPC). KCNQ1OT1, microRNA (miR)‑454 and ubiquitin specific peptidase 47 (USP47) expression levels were measured via reverse transcription‑quantitative PCR. 5‑8F/DDP and SUNE‑1/DDP cell viability and chemosensitivity were assessed by performing Cell Counting Kit‑8 assays. Colony forming and Transwell assays were conducted to assess the effect of the KCNQ1OT1/miR‑454/USP47 axis on DDP resistance in NPC cells. The association between miR‑454 and KCNQ1OT1 or USP47 was verified via bioinformatics analysis, dual‑luciferase reporter assays and RIP assays. KCNQ1OT1 and USP47 expression levels were significantly upregulated, whereas miR‑454 expression levels were significantly downregulated in DDP‑resistant NPC cells compared with parental NPC cells. KCNQ1OT1 knockdown promoted chemosensitivity in DDP‑resistant NPC cells (5‑8F/DDP and SUNE‑1/DDP), as indicated by significantly decreased cell proliferation, migration and invasion in the short hairpin RNA (sh)KCNQ1OT1 group compared with the sh‑negative control (NC) group. Moreover, miR‑454 was identified as a target of KCNQ1OT1. KCNQ1OT1 overexpression significantly reversed miR‑454 overexpression‑mediated effects on NPC cell viability and DDP resistance. Furthermore, the results indicated that miR‑454 directly targeted USP47. Compared with the shNC group, USP47 knockdown significantly suppressed NPC cell viability and DDP resistance, which was significantly reversed by co‑transfection with miR‑454 inhibitor. Furthermore, compared with the shNC group, KCNQ1OT1 knockdown significantly downregulated USP47 expression, which was significantly counteracted by miR‑454 knockdown. Collectively, the results of the present study indicated that KCNQ1OT1 enhanced DDP resistance in NPC cells via the miR‑454/USP47 axis, suggesting a potential therapeutic target for patients with DDP‑resistant NPC.

Silencing of HuR Inhibits Osteosarcoma Cell Epithelial-Mesenchymal Transition via AGO2 in Association With Long Non-Coding RNA XIST

Background

Osteosarcoma (OS) is a highly malignant and aggressive bone tumor. This study was performed to explore the mechanisms of HuR (human antigen R) in the progression of OS.

Methods

HuR expression levels in OS tissues and cells were detected by immunohistochemistry and western blotting. HuR siRNA was transfected into SJSA-1 OS cells to downregulate HuR expression, and then cell proliferation, migration, and epithelial-mesenchymal transition (EMT) were evaluated. RNA immunoprecipitation was performed to determine the association of the long non-coding RNA (lncRNA) XIST and argonaute RISC catalytic component (AGO) 2 with HuR. Fluorescence in situ hybridization analysis was performed to detect the expression of lncRNA XIST. Western blotting and immunofluorescence assays were performed to observe AGO2 expression after HuR or/and lncRNA XIST knockdown.

Results

Knockdown of HuR repressed OS cell migration and EMT. AGO2 was identified as a target of HuR and silencing of HuR decreased AGO2 expression. The lncRNA XIST was associated with HuR-mediated AGO2 suppression. Moreover, knockdown of AGO2 significantly inhibited cell proliferation, migration, and EMT in OS.

Conclusion

Our findings indicate that HuR knockdown suppresses OS cell EMT by regulating lncRNA XIST/AGO2 signaling.

MicroRNA-497-5p Is Downregulated in Hepatocellular Carcinoma and Associated with Tumorigenesis and Poor Prognosis in Patients

Background

MicroRNAs (miRNAs) have been demonstrated to exhibit important regulatory roles in multiple malignancies, including hepatocellular carcinoma (HCC). hsa-miR-497-5p was reported to involve in cancer progression and poor prognosis in many kinds of tumors. However, the expression and its clinical significance of hsa-miR-497-5p in HCC remain unclear.

Methods

In the present study, we investigated the expression of hsa-miR-497-5p in HCC and analyzed the correction of clinical features with prognosis. The expression levels of hsa-miR-497-5p and potential target genes were analyzed in HCC and adjacent noncancerous tissues using The Cancer Genome Atlas (TCGA) database and Gene Expression Omnibus (GEO) datasets. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to analyze hsa-miR-497-5p levels in 328 HCC tissues and 30 paired adjacent noncancer tissues. Overall survival (OS) and progression-free survival (PFS) of patients with HCC were assessed using the Kaplan-Meier method and the log-rank test.

Results

The hsa-miR-497-5p expression levels were decreased, and its target genes ACTG1, CSNK1D, PPP1CC, and BIRC5 were upregulated in HCC tissues compared with normal tissues. Lower levels of hsa-miR-497-5p expression and higher levels of the four target genes were significantly associated with higher tumor diameter. Moreover, patients with lower hsa-miR-497-5p expression and higher target genes levels had shorter OS.

Conclusion

The expression levels of hsa-miR-497-5p may play an important regulatory role in HCC and are closely correlated with HCC progression and poor prognosis in patients. The hsa-miR-497-5p may be a specific therapeutic target for the treatment of HCC.

MicroRNA-34a: Potent Tumor Suppressor, Cancer Stem Cell Inhibitor, and Potential Anticancer Therapeutic

Overwhelming evidence indicates that virtually all treatment-naive tumors contain a subpopulation of cancer cells that possess some stem cell traits and properties and are operationally defined as cancer cell stem cells (CSCs). CSCs manifest inherent heterogeneity in that they may exist in an epithelial and proliferative state or a mesenchymal non-proliferative and invasive state. Spontaneous tumor progression, therapeutic treatments, and (epi)genetic mutations may also induce plasticity in non-CSCs and reprogram them into stem-like cancer cells. Intrinsic cancer cell heterogeneity and induced cancer cell plasticity, constantly and dynamically, generate a pool of CSC subpopulations with varying levels of epigenomic stability and stemness. Despite the dynamic and transient nature of CSCs, they play fundamental roles in mediating therapy resistance and tumor relapse. It is now clear that the stemness of CSCs is coordinately regulated by genetic factors and epigenetic mechanisms. Here, in this perspective, we first provide a brief updated overview of CSCs. We then focus on microRNA-34a (miR-34a), a tumor-suppressive microRNA (miRNA) devoid in many CSCs and advanced tumors. Being a member of the miR-34 family, miR-34a was identified as a p53 target in 2007. It is a bona fide tumor suppressor, and its expression is dysregulated and downregulated in various human cancers. By targeting stemness factors such as NOTCH, MYC, BCL-2, and CD44, miR-34a epigenetically and negatively regulates the functional properties of CSCs. We shall briefly discuss potential reasons behind the failure of the first-in-class clinical trial of MRX34, a liposomal miR-34a mimic. Finally, we offer several clinical settings where miR-34a can potentially be deployed to therapeutically target CSCs and advanced, therapy-resistant, and p53-mutant tumors in order to overcome therapy resistance and curb tumor relapse.

Identification and validation of potential mRNA- microRNA- long-noncoding RNA (mRNA-miRNA-lncRNA) prognostic signature for cervical cancer

Cervical cancer is one of the most common causes of cancer deaths in women due to poor prognosis and high mortality rates. A novel mRNA-miRNA-lncRNA signature linked to prognosis of cervical cancer is needed to help clinicians judge the prognosis of individual patients more accurately. On the basis of GEO datasets, a total of 161 upregulated and 242 downregulated DE-mRNAs were identified firstly. Among them, eight potential biomarkers were found to have prognostic values with cervical cancer and miRNAs-lncRNAs related to these biomarkers were then analyzed to create mRNA-miRNA-lncRNA networks in cervical cancer. Moreover, in vitro experiments such as qRT-PCR, western blot and Edu assays were also performed to validate these promising targets. On the basis of these findings, a total of eight mRNA-miRNA-lncRNA subnetworks were finally established as a novel mRNA-miRNA-lncRNA signature and independent prognostic indicator of clinically relevant parameters by ROC analysis, univariate and multivariate Cox regression. Since some work of validation was done, it is believed that this mRNA-miRNA-lncRNA prognostic signature may be applied as a potential clinical judgment to estimate the prognosis of cervical cancer.

Identification of LINC00665-miR-let-7b-CCNA2 competing endogenous RNA network associated with prognosis of lung adenocarcinoma

Prognosis of patients with lung cancer remains extremely poor; thus, we sought to unearth novel competing endogenous RNA (ceRNA) networks associated with the prognosis of lung adenocarcinoma (LUAD). Aberrant mRNAs were identified from the intersection of three Gene Expression Omnibus (GEO) datasets. A protein–protein interaction (PPI) network was constructed, and miRNAs and long noncoding RNAs (lncRNAs) upstream of mRNAs were predicted. In the present study, 402 upregulated and 638 downregulated genes in lung cancer tissues were identified. Functional analysis showed significant enrichment of cancer pathways. In these top hub genes, 10 upregulated and 7 downregulated genes had substantial prognostic values in LUAD. Thirty-seven miRNAs were predicted to target 17 key genes, and only five miRNAs exhibited prognostic correlation. Through stepwise reverse prediction and validation from miRNA to lncRNA, four key lncRNAs were identified using expression and survival analysis. Ultimately, the co-expression analysis identified LINC00665-miR-let-7b-CCNA2 as the key ceRNA network associated with the prognosis of LUAD. We successfully constructed a novel ceRNA network wherein each component was significantly associated with the prognosis of LUAD. Hence, we propose that this network may provide key biomarkers or potential therapeutic targets for LUAD prognosis.

LINC01315 promotes the aggressive phenotypes of papillary thyroid cancer cells by sponging miR-497-5p

Dysregulation of the long intergenic noncoding RNA 01315 (LINC01315) has recently been demonstrated in cancer. However, the role of LINC01315 in papillary thyroid cancer (PTC) has not been determined. We attempted to determine the function of LINC01315 in PTC. The levels of LINC01315 were higher in thyroid carcinoma tissues and cell lines compared with that in noncancerous tissues or normal cells, respectively. LINC01315 knockdown significantly inhibited the in vitro colony formation and invasion of PTC cells. Upregulation of LINC01315 produced opposite effects. Bioinformatic analysis and luciferase reporter assays indicated direct binding of miR-497-5p to LINC01315. Gain- and loss-of-function assays indicated that miR-497-5p acts as a suppressive miRNA in PTC. Furthermore, LINC01315 facilitated the growth and invasion of PTC cells by sponging miR-497-5p. Our results demonstrated the critical role of the LINC01315-miR-497-5p axis in the growth and invasion of PTC cells.

Down-regulation of the tumor suppressor miR-34a contributes to head and neck cancer by up-regulating the MET oncogene and modulating tumor immune evasion

BACKGROUND

MicroRNAs (miRs) have been shown to play an important role in tumorigenesis, including in head and neck squamous cell carcinoma (HNSCC). The miR-34 family is thought to play a role in tumor suppression, but the exact mechanism of their action in HNSCC is not well understood. Moreover, the impact of chromosomal changes and mutation status on miR-34a expression remains unknown.

METHODS

Differential expression of miR-34a, MET, and genomic alterations were assessed in the Cancer Genome Atlas (TCGA) datasets as well as in primary HNSCC and adjacent normal tissue. The biological functions of miR-34a in HNSCC were investigated in samples derived from primary human tumors and HNSCC cell lines. The expression of MET was evaluated using immunohistochemistry, and the molecular interaction of miR-34a and MET were demonstrated by RNA pulldown, RNA immunoprecipitation, luciferase reporter assay, and rescue experiments. Lastly, locked nucleic acid (LNA) miRs in mouse xenograft models were used to evaluate the clinical relevance of miR-34a in HNSCC tumor growth and modulation of the tumor microenvironment in vivo.

RESULTS

Chromosome arm 1p loss and P53 mutations are both associated with lower levels of miR-34a. In HNSCC, miR-34a acts as a tumor suppressor and physically interacts with and functionally targets the proto-oncogene MET. Our studies found that miR-34a suppresses HNSCC carcinogenesis, at least in part, by downregulating MET, consequently inhibiting HNSCC proliferation. Consistent with these findings, administration of LNA-miR-34a in an in vivo model of HNSCC leads to diminished HNSCC cell proliferation and tumor burden in vitro and in vivo, represses expression of genes involved in epithelial-mesenchymal transition, and negates the oncogenic effect of MET in mouse tumors. Consistently, LNA-miR-34a induced a decreased number of immunosuppressive PDL1-expressing tumor-associated macrophages in the tumor microenvironment. In HNSCC patient samples, higher levels of miR-34a are significantly associated with a higher frequency of Th1 cells and CD8 naïve T cells.

CONCLUSIONS

Our results demonstrate that miR-34a directly targets MET and maintains anti-tumor immune activity. We propose miR-34a as a potential new therapeutic approach for HNSCC.

Inhibition of long non-coding RNA XIST upregulates microRNA-149-3p to repress ovarian cancer cell progression

Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) play critical roles in human diseases. We aimed to clarify the role of lncRNA X-inactive specific transcript (XIST)/miR-149-3p/forkhead box P3 (FOXP3) axis in ovarian cancer (OC) cell growth. XIST, miR-149-3p and FOXP3 expression in OC tissues and cell lines was assessed, and the predictive role of XIST in prognosis of OC patients was analyzed. The OC cell lines were screened and accordingly treated with silenced/overexpressed XIST plasmid or miR-149-3p mimic/inhibitor, and then the proliferation, invasion, migration, colony formation ability, apoptosis, and cell cycle distribution of OC cells were measured. Effect of altered XIST and miR-149-3p on tumor growth in vivo was observed. Online website prediction and dual luciferase reporter gene were implemented to detect the targeting relationship of lncRNA XIST, miR-149-3p, and FOXP3. XIST and FOXP3 were upregulated, whereas miR-149-3p was downregulated in OC tissues and cells. High XIST expression indicated a poor prognosis of OC. Inhibition of XIST or elevation of miR-149-3p repressed proliferation, invasion, migration, and colony formation ability, and promoted apoptosis and cell cycle arrest of HO-8910 cells. In SKOV3 cells upon treatment of overexpressed XIST or reduction of miR-149-3p, there exhibited an opposite tendency. Based on online website prediction, dual luciferase reporter gene, and RNA pull-down assays, we found that there was a negative relationship between XIST and miR-149-3p, and miR-149-3p downregulated FOXP3 expression. This study highlights that knockdown of XIST elevates miR-149-3p expression to suppress malignant behaviors of OC cells, thereby inhibiting OC development.

The emerging role of non-coding RNAs in the regulation of PI3K/AKT pathway in the carcinogenesis process

The PI3K/AKT pathway is an intracellular signaling pathway with an indispensable impact on cell cycle control. This pathway is functionally related with cell proliferation, cell survival, metabolism, and quiescence. The crucial role of this pathway in the development of cancer has offered this pathway as a target of novel anti-cancer treatments. Recent researches have demonstrated the role of microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) in controlling the PI3K/AKT pathway. Some miRNAs such as miR-155-5p, miR-328-3p, miR-125b-5p, miR-126, miR-331-3p and miR-16 inactivate this pathway, while miR-182, miR-106a, miR-193, miR-214, miR-106b, miR-93, miR-21 and miR-103/107 enhance activity of this pathway. Expression levels of PI3K/AKT-associated miRNAs could be used to envisage the survival of cancer patients. Numerous lncRNAs such as GAS5, FER1L4, LINC00628, PICART1, LOC101928316, ADAMTS9-AS2, SLC25A5-AS1, MEG3, AB073614 and SNHG6 interplay with this pathway. Identification of the impact of miRNAs and lncRNAs in the control of the activity of PI3K/AKT pathway would enhance the efficacy of targeted therapies against this pathway. Moreover, each of the mentioned miRNAs and lncRNAs could be used as a putative therapeutic candidate for the interfering with the carcinogenesis. In the current study, we review the role of miRNAs and lncRNAs in controlling the PI3K/AKT pathway and their contribution to carcinogenesis.