Long non-coding RNA XIST promotes the development of esophageal cancer by sponging miR-494 to regulate CDK6 expression

Effect of lncRNA XIST on acute myeloid leukemia cells via miR-142-5p-PFKP axis

Acute myeloid leukemia (AML) is the common blood cancer in hematopoietic system-related diseases and has a poor prognosis. Studies have shown that long non-coding RNAs (lncRNAs) are closely related to the pathogenesis of a variety of diseases, including AML. However, the specific molecular mechanism remains unclear. Hence, the objective of this study was to investigate the effect and mechanism of lncRNA X inactive specific transcript (lncRNA XIST) on AML. To achieve our objective, some tests were performed. Quantitative real-time polymerase chain reaction (qRT-PCR) was utilized to detect the expression of lncRNA XIST, miR-142-5p and the platelet isoform of phosphofructokinase (PFKP). The targeting relationship between miR-142-5p and lncRNA XIST and PFKP was verified by Pearson correlation analysis, dual-luciferase reporter assay, and pull-down assay. Functional experiments were used to analyze the effect and mechanism of action of knocking down lncRNA XIST on THP-1 and U937 cells. Compared with bone marrow cells, lncRNA XIST and PFKP expression levels were up-regulated and miR-142-5p expression levels were down-regulated in AML. Further analysis revealed that lncRNA XIST targeted and bound to miR-142-5p, and PFKP was a target gene of miR-142-5p. Knockdown of lncRNA XIST significantly promoted miR-142-5p expression to down-regulate PFKP in THP-1 and U937 cells, while the cell proliferation, cell viability, and cell cycle arrest were inhibited and apoptosis was increased. Knockdown of miR-142-5p reversed the functional impact of lncRNA XIST knockdown on AML cells. In conclusion, down-regulation of lncRNA XIST can affect the progression of AML by regulating miR-142-5p.

Harnessing the supremacy of MEG3 LncRNA to defeat gastrointestinal malignancies

Evidence suggests that long non-coding RNAs (lncRNAs) play a pivotal role in the carcinogenesis and progression of various human malignancies including gastrointestinal malignancies. This comprehensive review reports the functions and mechanisms of the lncRNA maternally expressed gene 3 (MEG3) involved in gastrointestinal malignancies. It summarizes its roles in mediating the regulation of cellular proliferation, apoptosis, migration, invasiveness, epithelial-to-mesenchymal transition, and drug resistance in several gastrointestinal cancers such as colorectal cancer, gall bladder cancer, pancreatic cancer, gastric cancer, esophageal cancer, cholangiocarcinoma, gastrointestinal stromal tumors and most importantly, hepatocellular carcinoma. In addition, the authors briefly highlight its implicated mechanistic role and interactions with different non-coding RNAs and oncogenic signaling cascades. This review presents the rationale for developing non coding RNA-based anticancer therapy via harnessing the power of MEG3 in gastrointestinal malignancies.

Long Non-coding RNA X-Inactive Specific Transcript Promotes Esophageal Squamous Cell Carcinoma Progression via the MicroRNA 34a/Zinc Finger E-box-Binding Homeobox 1 Pathway

BACKGROUND

The long non-coding RNA X-inactive specific transcript (XIST) plays a crucial role in transcriptional silencing of the X chromosome. Zinc finger E-box-binding homeobox 1 (ZEB1) is a transcription factor involved in epithelial-mesenchymal transition (EMT) regulation.

AIMS

This study aimed to investigate the impact of XIST on esophageal squamous cell carcinoma (ESCC) progression and its underlying mechanism involving the miR-34a/ZEB1/E-cadherin/EMT pathway.

METHODS

XIST and ZEB1 expression were analyzed using quantitative PCR and immunohistochemistry. XIST knockdown was achieved in KYSE150 ESCC cells using siRNA or shRNA lentivirus transfection. Proliferation, migration, and invasion abilities were assessed, and luciferase reporter assays were performed to confirm XIST-miR-34a-ZEB1 interactions. In vivo ESCC growth was evaluated using a xenograft mouse model.

RESULTS

XIST and ZEB1 were upregulated in tumor tissues, correlating with metastasis and reduced survival. XIST knockdown inhibited proliferation, migration, and invasion of KYSE150 cells. It decreased ZEB1 expression, increased E-cadherin and miR-34a levels. Luciferase reporter assays confirmed miR-34a binding to XIST and ZEB1. XIST knockdown suppressed xenograft tumor growth.

CONCLUSION

XIST promotes ESCC progression via the miR-34a/ZEB1/E-cadherin/EMT pathway. Targeting the XIST/miR-34a/ZEB1 axis holds therapeutic potential and serves as a prognostic biomarker in ESCC.

Noncoding RNAs as regulators of STAT3 pathway in gastrointestinal cancers: Roles in cancer progression and therapeutic response

Gastrointestinal (GI) tumors (cancers of the esophagus, gastric, liver, pancreas, colon, and rectum) contribute to a large number of deaths worldwide. STAT3 is an oncogenic transcription factor that promotes the transcription of genes associated with proliferation, antiapoptosis, survival, and metastasis. STAT3 is overactivated in many human malignancies including GI tumors which accelerates tumor progression, metastasis, and drug resistance. Research in recent years demonstrated that noncoding RNAs (ncRNAs) play a major role in the regulation of many signaling pathways including the STAT3 pathway. The major types of endogenous ncRNAs that are being extensively studied in oncology are microRNAs, long noncoding RNAs, and circular RNAs. These ncRNAs can either be tumor-promoters or tumor-suppressors and each one of them imparts their activity via different mechanisms. The STAT3 pathway is also tightly modulated by ncRNAs. In this article, we have elaborated on the tumor-promoting role of STAT3 signaling in GI tumors. Subsequently, we have comprehensively discussed the oncogenic as well as tumor suppressor functions and mechanism of action of ncRNAs that are known to modulate STAT3 signaling in GI cancers.

lncRNA XIST/miR‑129‑2‑3p axis targets CCP110 to regulate the proliferation, invasion and migration of endometrial cancer cells

Centromere coiled-coil protein 110 (CCP110) plays a role in the development of several types of cancer; however, its regulatory mechanism and role in endometrial cancer is unclear. The present study revealed that CCP110 is regulated by a signaling pathway involving microRNA (miR/miRNA)-129-2-3p and the long non-coding RNA (lncRNA) X-inactive-specific transcript (XIST), and plays a role in controlling the proliferation, migration and invasion of endometrial cancer cells. CCP110 was upregulated in human endometrial cancer tissues, as revealed by immunohistochemistry, and high expression of the protein was related to reduced overall survival of the patients. Genetic knockdown of CCP110 by small interfering RNA promoted apoptosis and suppressed the proliferation, migration, invasion and colony formation of endometrial cancer cells significantly in the endometrial cancer Ishikawa and HEC-1B cell lines, as assessed by flow cytometry, and Cell Counting Kit-8, Transwell and colony formation assays. A bioinformatics analysis and luciferase reporter assay revealed that CCP110 is a target of miR-129-2-3p. Overexpression of miR-129-2-3p mimic fragments inhibited the proliferation, migration and invasion of endometrial cancer cells significantly, while co-overexpression of CCP110 counteracted these inhibitory effects. The expression level of the lncRNA XIST was upregulated significantly in endometrial cancer tissues, as assessed by reverse transcription-quantitative PCR assay, while that of miR-129-2-3p was downregulated significantly. A bioinformatics analysis and luciferase reporter assay showed that XIST could inhibit miR-129-2-3p via a miRNA sponge effect. Furthermore, co-overexpression of XIST antagonized the inhibitory effect of the miR-129-2-3p mimic on the luciferase reporter gene signal and protein expression of CCP110. Co-overexpression of XIST also abolished the inhibitory effect of the miR-129-2-3p mimic on the proliferation, migration and invasion of endometrial cancer cells. Overall, these data identified a novel regulatory mechanism of CCP110 involving XIST and miR-129-2-3p, which affected the development of endometrial carcinoma. CCP110, XIST and miR-129-2-3p could represent novel targets for the clinical treatment of endometrial cancer.

Natural flavonoids alleviate glioblastoma multiforme by regulating long non-coding RNA

Glioblastoma multiforme (GBM) is one of the most common primary malignant brain tumors in adults. Due to the poor prognosis of patients, the median survival time of GBM is often less than 1 year. Therefore, it is very necessary to find novel treatment options with a good prognosis for the treatment or prevention of GBM. In recent years, flavonoids are frequently used to treat cancer. It is a new attractive molecule that may achieve this promising treatment option. Flavonoids have been proved to have many biological functions, such as antioxidation, prevention of angiogenesis, anti-inflammation, inhibition of cancer cell proliferation, and protection of nerve cells. It has also shown the ability to regulate long non-coding RNA (LncRNA). Studies have confirmed that flavonoids can regulate epigenetic modification, transcription, and change microRNA (miRNA) expression of GBM through lncRNA at the gene level. It also found that flavonoids can induce apoptosis and autophagy of GBM cells by regulating lncRNA. Moreover, it can improve the metabolic abnormalities of GBM, interfere with the tumor microenvironment and related signaling pathways, and inhibit the angiogenesis of GBM cells. Eventually, flavonoids can block the tumor initiation, growth, proliferation, differentiation, invasion, and metastasis. In this review, we highlight the role of lncRNA in GBM cancer progression and the influence of flavonoids on lncRNA regulation. And emphasize their expected role in the prevention and treatment of GBM.

Novel thiazolidines of potential anti-proliferation properties against esophageal squamous cell carcinoma via ERK pathway

The discovery of a new class of extracellular-signal-regulated kinase (ERK) inhibitors has been achieved via developing novel 2-imino-5-arylidene-thiazolidine analogues. A novel synthetic method employing a solid support-mediated reaction was used to construct the targeted thiazolidines through a cascade reaction with good yields. The chemical and physical stability of the new thiazolidine library has successfully been achieved by blocking the labile C5-position to aerobic oxidation. A cell viability study was performed using esophageal squamous cell carcinoma cell lines (KYSE-30 and KYSE-150) and non-tumorous esophageal epithelial cell lines (HET-1A and NES-G4T) through utilization of an MTT assay, revealing that (Z)-5-((Z)-4-bromobenzylidene)-N-(4-methoxy-2-nitrophenyl)-4,4-dimethylthiazolidin-2-imine (6g) was the best compound among the synthesized library in terms of selectivity. DAPI staining experiments were performed to visualize the morphological changes and to investigate the apoptotic activity. Moreover, western blots were used to probe the mechanism/pathway behind the observed activity/selectivity of thiazolidine 6g which established selective inhibition of phosphorylation in the ERK pathway. Molecular modeling techniques have been utilized to confirm the observed activity. A molecular docking study revealed similar binding interactions between the synthesized thiazolidines and reported co-crystalized inhibitors with ERK proteins. Thus, the present study provides a starting point for the development of interesting bioactive 2-imino-5-arylidene-thiazolidines.

Long Non-Coding RNA DUXAP8 Acts as an Oncogene in Sinonasal Squamous Cell Carcinoma Through miR-584-5p/FNDC3B Pathway

Sinonasal squamous cell carcinoma (SNSCC) is one of the least frequent carcinomas in the head and neck and accounts for 60% to 75% of sinonasal malignancies. The role of long non-coding RNAs (lncRNAs) in cancer development has drawn great attention over the years. The current study intended to assess the role and specific mechanism of lncRNA double homeobox A pseudogene 8 (DUXAP8) in SNSCC. Quantitative real-time PCR (qRT-PCR) analysis was implemented to assess the expression level of DUXAP8, microRNA-584-5p (miR-584-5p), and fibronectin type III domain containing 3B (FNDC3B). Proliferation assays included colony formation assay, Cell Counting Kit-8 (CCK-8) assay, and 5-ethynyl-2′-deoxyuridine (EdU) assay. Transwell assays were implemented to monitor cell migration and invasion. Cell apoptosis was evaluated via terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL) and JC-1 experiments. Mechanism experiments included RNA pull-down assay, RNA binding protein immunoprecipitation (RIP) assay, and luciferase reporter assay. DUXAP8 is overexpressed in SNSCC cells. Functionally, DUXAP8 silencing suppresses the malignant progression of SNSCC. Furthermore, DUXAP8 up-regulates the expression of FNDC3B via sponging miR-584-5p. Rescue experiments demonstrated that DUXAP8 mediates the progression of SNSCC via up-regulating FNDC3B expression. In conclusion, DUXAP8 acts as an oncogene in SNSCC, which may be a new molecular marker for SNSCC.

Pyroptosis in development, inflammation and disease

In the early 2000s, caspase-1, an important molecule that has been shown to be involved in the regulation of inflammation, cell survival and diseases, was given a new function: regulating a new mode of cell death that was later defined as pyroptosis. Since then, the inflammasome, the inflammatory caspases (caspase-4/5/11) and their substrate gasdermins (gasdermin A, B, C, D, E and DFNB59) has also been reported to be involved in the pyroptotic pathway, and this pathway is closely related to the development of various diseases. In addition, important apoptotic effectors caspase-3/8 and granzymes have also been reported to b involved in the induction of pyroptosis. In our article, we summarize findings that help define the roles of inflammasomes, inflammatory caspases, gasdermins, and other mediators of pyroptosis, and how they determine cell fate and regulate disease progression.

Characterization of plasma exosomal microRNAs in responding to radiotherapy of human esophageal squamous cell carcinoma

Radiotherapy is one of the main treatment methods for esophageal squamous cell carcinoma (ESCC). Previous research has shown that plasma exosomal microRNAs (miRNAs) can predict therapeutic outcome. In the present study, to identify potential exosomal miRNAs that respond to radiotherapy, plasma exosomal miRNAs from ESCC patients undergoing radiotherapy were isolated and sequenced. Upregulated and downregulated miRNAs were detected from patients pre- and post-radiotherapy, and it was found that they play distinct roles in DNA damage process and endosomal mediated transport. Based on wound healing and Cell Counting Kit-8 assays in TE-1 human esophageal cancer cells, it was identified that representative miRNA miR-652 and miR-30a alter migration but not proliferation. The present findings identified differentially expressed miRNAs in responding to radiotherapy, and added a reference to explore non-invasive plasma biomarkers to evaluate therapeutic effects in ESCC.

Molecular mechanism, regulation, and therapeutic targeting of the STAT3 signaling pathway in esophageal cancer (Review)

Esophageal cancer (EC) is the seventh most common cancer globally, and the overall 5-year survival rate is only 20%. Signal transducer and activator of transcription 3 (STAT3) is aberrantly activated in EC, and its activation is associated with a poor prognosis. STAT3 can be activated by canonical pathways such as the JAK/STAT3 pathway as well as non-canonical pathways including the Wnt/STAT3 and COX2/PGE2/STAT3 pathways. Activated STAT3, present as phosphorylated STAT3 (p-STAT3), can be transported into the nucleus to regulate downstream genes, including VEGF, cyclin D1, Bcl-xL, and matrix metalloproteinases (MMPs), to promote cancer cell proliferation and induce resistance to therapy. Non-coding RNAs, including microRNAs (miRNAs/miRs), circular RNAs (circRNAs), and long non-coding RNAs (lncRNAs), play a vital role in regulating the STAT3 signaling pathway in EC. Several miRNAs promote or suppress the function of STAT3 in EC, while lncRNAs and circRNAs primarily promote the effects of STAT3 and the progression of cancer. Additionally, various drugs and natural compounds can target STAT3 to suppress the malignant behavior of EC cells, providing novel insights into potential EC therapies.

Long Non-Coding RNA DUXAP8 Acts as an Oncogene in Sinonasal Squamous Cell Carcinoma Through miR-584-5p/FNDC3B Pathway

Sinonasal squamous cell carcinoma (SNSCC) is one of the least frequent carcinomas in the head and neck and accounts for 60% to 75% of sinonasal malignancies. The role of long non-coding RNAs (lncRNAs) in cancer development has drawn great attention over the years. The current study intended to assess the role and specific mechanism of lncRNA double homeobox A pseudogene 8 (DUXAP8) in SNSCC. Quantitative real-time PCR (qRT-PCR) analysis was implemented to assess the expression level of DUXAP8, microRNA-584-5p (miR-584-5p), and fibronectin type III domain containing 3B (FNDC3B). Proliferation assays included colony formation assay, Cell Counting Kit-8 (CCK-8) assay, and 5-ethynyl-2'-deoxyuridine (EdU) assay. Transwell assays were implemented to monitor cell migration and invasion. Cell apoptosis was evaluated via terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL) and JC-1 experiments. Mechanism experiments included RNA pull-down assay, RNA binding protein immunoprecipitation (RIP) assay, and luciferase reporter assay. DUXAP8 is overexpressed in SNSCC cells. Functionally, DUXAP8 silencing suppresses the malignant progression of SNSCC. Furthermore, DUXAP8 up-regulates the expression of FNDC3B via sponging miR-584-5p. Rescue experiments demonstrated that DUXAP8 mediates the progression of SNSCC via up-regulating FNDC3B expression. In conclusion, DUXAP8 acts as an oncogene in SNSCC, which may be a new molecular marker for SNSCC.

Silencing of histone deacetylase 3 suppresses the development of esophageal squamous cell carcinoma through regulation of miR-494-mediated TGIF1

BACKGROUND

Deacetylation of histones by histone deacetylase 3 (HDAC3) acts importantly in modulating apoptosis, DNA damage and cellular progression. Herein, we aimed to unravel the functional role of HDAC3 in a lethal disease, esophageal squamous cell carcinoma (ESCC).

METHODS

The expression of HDAC3 in clinically collected ESCC tissues was determined by RT-qPCR and immunohistochemistry. As revealed from bioinformatics analysis, the putative relations between HDAC3 and microRNA-494 (miR-494) and between miR-494 and transforming growth factor beta (TGFβ)-inducing factor 1 (TGIF1) were further verified by chromatin immunoprecipitation and dual-luciferase reporter gene assay. Functional roles of shRNA-mediated depletion of HDAC3, miR-494 mimic and overexpressed TGIF1 were explored by gain- and loss-of-function assays with regard to ESCC cell biological behaviors. A nude mouse model of ESCC was developed for in vivo validation.

RESULTS

HDAC3 was highly expressed in ESCC tissues, suggestive of poor prognosis while TGIF1 was upregulated and miR-494 was downregulated. Mechanistic investigation revealed that HDAC3 inhibited miR-494 expression and TGIF1 was a direct target of miR-494. Furthermore, silencing HDAC3 or overexpressing miR-494 was demonstrated to suppress aggressive phenotypes of ESCC cells both in vitro through the activated TGFβ signaling pathway and in vivo, while TGIF1 overexpression induced opposite results.

CONCLUSION

Collectively, our findings provided demonstration regarding the oncogenic property of HDAC3 in ESCC via the miR-494/TGIF1/TGFβ axis.

A novel lncRNA-miRNA-mRNA triple network identifies lncRNA XIST as a biomarker for acute myocardial infarction

Despite the well-established role of long non-coding RNAs (lncRNAs) across various biological processes, their mechanisms in acute myocardial infarction (AMI) are not fully elucidated. The GSE34198 dataset from the Gene Expression Omnibus (GEO) database, which comprised 49 specimens from individuals with AMI and 47 specimens from controls, was extracted and analysed using the weighted gene co-expression network analysis (WGCNA) package. Twenty-seven key genes were identified through a combination of the degree and gene significance (GS) values, and the CDC42 (degree = 64), JAK2 (degree = 41), and CHUK (degree = 30) genes were identified as having the top three-degree values among the 27 genes. Potential interactions between lncRNA, miRNAs and mRNAs were predicted using the starBase V3.0 database, and a lncRNA-miRNA-mRNA triple network containing the lncRNA XIST, twenty-one miRNAs and three hub genes (CDC42, JAK2 and CHUK) was identified. RT-qPCR validation showed that the expression of the JAK2 and CDC42 genes and the lncRNA XIST was noticeably increased in samples from patients with AMI compared to normal samples. Pearson's correlation analysis also proved that JAK2 and CDC42 expression levels correlated positively with lncRNA XIST expression levels. The area under ROC curve (AUC) of lncRNA XIST was 0.886, and the diagnostic efficacy of the lncRNA XIST was significantly better than that of JAK2 and CDC42. The results suggested that the lncRNA XIST appears to be a risk factor for AMI likely through its ability to regulate JAK2 and CDC42 gene expressions, and it is expected to be a novel and reliable biomarker for the diagnosis of AMI.

Long non-coding RNA Xist contribution in systemic lupus erythematosus and rheumatoid arthritis

Growing evidence points towards the role of the long non-coding (lnc)-RNA Xist expressed in female cells as a predominant key actor for the sex bias observed in systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Indeed, in female cells, lnc-Xist controls transcription directly by spreading across the inactivated X chromosome (Xi) and indirectly by sequestring miRNAs as a sponge. The inactivation process at Xi is altered in lymphocytes from SLE women and associated with important variations in ribonucleoproteins (RNP) associated with lnc-Xist. In fibroblast-like synoviocytes (FLS) and osteoclasts from RA women, proinflammatory and proliferative pathways are upregulated due to the sequestration effect exerted by lnc-Xist overexpression on miRNAs. The key role played by lnc-Xist in SLE and RA is further supported by it's knock down that recapitulates the SLE B cell extrafollicular profile and controls RA associated FLS proinflammatory cytokine production and proliferation.

The lncRNAs at X Chromosome Inactivation Center: Not Just a Matter of Sex Dosage Compensation

Non-coding RNAs (ncRNAs) constitute the majority of the transcriptome, as the result of pervasive transcription of the mammalian genome. Different RNA species, such as lncRNAs, miRNAs, circRNA, mRNAs, engage in regulatory networks based on their reciprocal interactions, often in a competitive manner, in a way denominated “competing endogenous RNA (ceRNA) networks” (“ceRNET”): miRNAs and other ncRNAs modulate each other, since miRNAs can regulate the expression of lncRNAs, which in turn regulate miRNAs, titrating their availability and thus competing with the binding to other RNA targets. The unbalancing of any network component can derail the entire regulatory circuit acting as a driving force for human diseases, thus assigning “new” functions to “old” molecules. This is the case of XIST, the lncRNA characterized in the early 1990s and well known as the essential molecule for X chromosome inactivation in mammalian females, thus preventing an imbalance of X-linked gene expression between females and males. Currently, literature concerning XIST biology is becoming dominated by miRNA associations and they are also gaining prominence for other lncRNAs produced by the X-inactivation center. This review discusses the available literature to explore possible novel functions related to ceRNA activity of lncRNAs produced by the X-inactivation center, beyond their role in dosage compensation, with prospective implications for emerging gender-biased functions and pathological mechanisms.

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.

Targeting long non coding RNA by natural products: Implications for cancer therapy

In spite of achieving substantial progress in its therapeutic strategies, cancer-associated prevalence and mortality are persistently rising globally. However, most malignant cancers either cannot be adequately diagnosed at the primary phase or resist against multiple treatments such as chemotherapy, surgery, radiotherapy as well as targeting therapy. In recent decades, overwhelming evidences have provided more convincing words on the undeniable roles of long non-coding RNAs (lncRNAs) in incidence and development of various cancer types. Recently, phytochemical and nutraceutical compounds have received a great deal of attention due to their inhibitory and stimulatory effects on oncogenic and tumor suppressor lncRNAs respectively that finally may lead to attenuate various processes of cancer cells such as growth, proliferation, metastasis and invasion. Therefore, application of phytochemicals with anticancer characteristics can be considered as an innovative approach for treating cancer and increasing the sensitivity of cancer cells to standard prevailing therapies. The purpose of this review was to investigate the effect of various phytochemicals on regulation of lncRNAs in different human cancer and evaluate their capabilities for cancer treatment and prevention.

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.

Erythropoietin Protects against Diffuse Alveolar Hemorrhage in Mice by Regulating Macrophage Polarization through the EPOR/JAK2/STAT3 Axis

Macrophages play an important role in the pathogenesis of systemic lupus erythematosus-associated diffuse alveolar hemorrhage (DAH). The immunomodulation of macrophage responses might be a potential approach for the prevention and treatment of DAH. Erythropoietin (EPO) could regulate macrophage bioactivities by binding to the EPO receptor expressing on macrophages. This study assessed the effects of EPO on DAH protection using an immune-mediated DAH murine model with macrophages as the major contributor. A DAH murine model was established in female C57BL/6 mice by an i.p. injection of pristane. We found that EPO administration alleviates DAH by reducing pulmonary macrophages recruitment and promoting phenotype switch toward M2 macrophages in vivo. EPO drove macrophages to the anti-inflammatory phenotype in the primary murine bone marrow-derived macrophages and macrophages cell line RAW 264.7 with LPS, IFN-γ, and IL-4 in vitro. Moreover, EPO treatment increases the expression of EPOR and decreases the expression of miR-494-3p, resulting in increased phosphorylation of JAK2 and STAT3. In conclusion, EPO can be a potential therapeutic agent in DAH by reducing cell apoptosis and regulating macrophage polarization through the EPOR/JAK2/STAT3 axis. Further studies are also needed to validate the direct target of miR-494-3p in regulating JAK2/STAT3 signaling transduction.

XIST: A Meaningful Long Noncoding RNA in NSCLC Process

BACKGROUND

A number of studies have proposed that lncRNA XIST plays a role in the development and chemosensitivity of NSCLC. Besides, XIST may become a potential therapeutic target for NSCLC patients. The aim of this review is to reveal the biological functions and exact mechanisms of XIST in NSCLC.

METHODS

In this review, relevant researches involving the relationship between XIST and NSCLC are collected through systematic retrieval of PubMed.

RESULTS

XIST is an oncogene in NSCLC and is abnormally upregulated in NSCLC tissues. Considerable evidence has shown that XIST plays a critical role in the proliferation, invasion, migration, apoptosis and chemosensitivity of NSCLC cells. XIST mainly functions as a ceRNA in the NSCLC process, while XIST also functions at transcriptional levels.

CONCLUSION

LncRNA XIST has the potential to become a novel biomolecular marker of NSCLC and a therapeutic target for NSCLC.

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.

The emerging role of long noncoding RNAs in esophageal carcinoma: from underlying mechanisms to clinical implications

Long noncoding RNAs (lncRNAs), a type of transcriptional product more than 200 nucleotides in length, have emerged as crucial regulators in human cancers. Accumulating data have recently indicated relationships between lncRNAs and esophageal carcinoma (EC). Of note, lncRNAs act as decoys/sponges, scaffolds, guides, and signals to regulate the expression of oncogenes or tumor suppressors at epigenetic, post-transcriptional, and protein levels, through which they exert their unique EC-driving or EC-suppressive functions. Moreover, the features of EC-related lncRNAs have been gradually exploited for developing novel diagnostic and therapeutic strategies in clinical scenarios. LncRNAs have the potential to be used as diagnostic and prognostic indicators individually or in combination with other clinical variables. Beyond these, although the time is not yet ripe, therapeutically targeting EC-related lncRNAs via gene editing, antisense oligonucleotides, RNA interference, and small molecules is likely one of the most promising therapeutic strategies for the next generation of cancer treatment. Herein, we focus on summarizing EC-driving/suppressive lncRNAs, as well as discussing their different features regarding expression profiles, modes of action, and oncological effects. Moreover, we further discuss current challenges and future developing possibilities of capitalizing on lncRNAs for EC early diagnosis and treatment.

Pyroptosis: mechanisms and diseases

Currently, pyroptosis has received more and more attention because of its association with innate immunity and disease. The research scope of pyroptosis has expanded with the discovery of the gasdermin family. A great deal of evidence shows that pyroptosis can affect the development of tumors. The relationship between pyroptosis and tumors is diverse in different tissues and genetic backgrounds. In this review, we provide basic knowledge of pyroptosis, explain the relationship between pyroptosis and tumors, and focus on the significance of pyroptosis in tumor treatment. In addition, we further summarize the possibility of pyroptosis as a potential tumor treatment strategy and describe the side effects of radiotherapy and chemotherapy caused by pyroptosis. In brief, pyroptosis is a double-edged sword for tumors. The rational use of this dual effect will help us further explore the formation and development of tumors, and provide ideas for patients to develop new drugs based on pyroptosis.

LncRNA PCGEM1 contributes to malignant behaviors of glioma by regulating miR-539-5p/CDK6 axis

Background: Glioma, one of the most prevalent and aggressive cancers, is regulated by long noncoding RNAs (lncRNAs). This study aims to research the functional mechanism of lncRNA PCGEM1 involved in glioma progression.

Methods: Expression levels of PCGEM1, miR-539-5p and CDK6 were analyzed by qRT-PCR in NHA, U251, U87, and LN229 cells or glioma tissues. shRNAs were used to knock down PCGEM1 in U251 and LN229 cells. Kaplan-Meier curve and log rank test were utilized to examine survival rate. CCK8 (Cell Counting Kit-8) assay, colony formation assay and EdU staining were conducted to detect cell proliferation. Transwell assay was performed to evaluate cell migration and invasion. Luciferase reporter assay was conducted to assess RNA interaction between PCGEM1 and miR-539-5p. Nude mice were used for tumor xenograft assay.

Results: LncRNA PCGEM1 was upregulated in glioma tissues and tumor cell lines. PCGEM1 upregulation predicted unsatisfactory prognosis. PCGEM1 knockdown inhibited proliferation, colony formation, migration and invasion. PCGEM1 knockdown delayed tumor growth in vivo. PCGEM1 played as a competing endogenous RNA (ceRNA) for miR-539-5p to promote CDK6 expression. MiR-539-5p mimics repressed glioma progression while CDK6 overexpression reversed the roles of PCGEM1 knockdown.

Conclusion: PCGEM1 knockdown suppressed glioma progression through sponging miR-539-5p and regulating CDK6 expression, implying PCGEM1 as a potential therapeutic target.

Long non-coding RNA XIST promotes the progression of esophageal squamous cell carcinoma through sponging miR-129-5p and upregulating CCND1 expression

Long non-coding RNA (lncRNA) X inactive specific transcript (XIST) has been identified as an oncogenic lncRNA in a series of human cancers, including esophageal squamous cell carcinoma (ESCC). In this study, we aimed to further explore the underlying mechanism of XIST on ESCC progression. qRT-PCR assay was used to determine the levels of XIST and miR-129-5p. Western blot analysis was performed to assess cyclin D1 (CCND1) expression. Bioinformatic analysis was performed using starBase v2.0 software. Dual-luciferase reporter and RNA immunoprecipitation assays were employed to confirm the interaction between XIST and miR-129-5p or miR-129-5p and CCND1. Cell cycle progression and apoptosis were measured by flow cytometric analysis, and cell migration and invasion were detected by transwell assay. Mouse studies were used to observe the effect of XIST silencing on tumor growth in vivo. Our results indicated that XIST was upregulated and miR-129-5p was downregulated in ESCC. XIST silencing or miR-129-5p overexpression repressed cell cycle progression, proliferation, migration, invasion, and promoted the apoptosis in ESCC cells. Moreover, XIST directly interacted with miR-129-5p and repressed miR-129-5p expression. MiR-129-5p mediated the regulatory effect of XIST on ESCC cell progression in vitro, and XIST promoted CCND1 expression by sponging miR-129-5p. Additionally, XIST silencing inhibited tumor growth in vivo. Our findings suggested that XIST silencing repressed the progression of ESCC at least partly through regulating the miR-129-5p/CCND1 axis. Targeting XIST might be a potential therapeutic strategy for ESCC treatment.

LncRNA XIST Inhibits the Progression of Oral Squamous Cell Carcinoma via Sponging miR-455-3p/BTG2 Axis

Objective

Oral squamous cell carcinoma (OSCC) is one of the most common cancers, accounting for over 90% of malignant lesions in the oral cavity. Long non-coding RNAs play an important role in the development of OSCC. This study aimed to investigate the effects of lncRNA XIST on the malignant behaviors of OSCC cells and its possible molecular mechanisms.

Methods

Real-time quantitative PCR and Western blot were used to detect the RNA and protein level, respectively. CAL27 and SCC25 cells with the lowest expression level of XIST were used for further study. MTT, transwell assay, colony formation, and xenograft model were applied to examine the effect of XIST on the progression of OSCC. FISH assay was performed to investigate the co-location of XIST and miR-455-3p in OSCC cells. The bioinformatics analysis, luciferase, and RNA pull down assay were utilized to predict and verify the target genes of miR-455-3p.

Results

XIST was downregulated in OSCC tissues and cell lines. Overexpression of XIST inhibited the proliferation, migration, and invasion ability of OSCC cells. Bioinformatics analysis and luciferase reporter assay confirmed XIST could bind to miR-455-3p. Besides, miR-455-3p directly targeted BTG2 in OSCC cells. Rescue experiments further confirmed the positive interaction between miR-455-3p and XIST as well as between miR-455-3p and BTG2.

Conclusion

XIST was down-regulated in OSCC. XIST regulated the expression of BTG2 via sponging miR-455-3p. XIST/miR-455-3p/BTG2 signal axis inhibited the malignant progression of OSCC.

Long non-coding RNA FALEC promotes colorectal cancer progression via regulating miR-2116-3p-targeted PIWIL1

BACKGROUND

Colorectal cancer (CRC) is one of the most common digestive malignant tumors globally. Focally amplified lncRNA on chromosome 1 (FALEC) is a novel lncRNA that has been reported to be involved in many biological processes during carcinogenesis. However, its role in CRC remains poorly understood.

METHODS

Gene expression at mRNA or protein level was measured by qRT-PCR or western blot, respectively. In vitro experiments including EdU, colony formation, flow cytometry, wound-healing and transwell assays, as well as in vivo xenograft experiment, were utilized to determine the functional role of FALEC in CRC. Relevant mechanical assays were performed to investigate the underlying molecular mechanism.

RESULTS

FALEC was aberrantly up-regulated in CRC. FALEC knockdown could impair CRC cell proliferation, migration and invasion, whereas facilitate cell apoptosis. MiR-2116-3p was revealed to be sponged by FALEC. PIWIL1 was identified as the target of miR-2116-3p. Mechanically, FALEC restored the expression of PIWIL1 via absorbing miR-2116-3p. MiR-2116-3p inhibition and PIWIL1 enrichment could counteract the anti-tumor impact induced by silenced FALEC on the oncogenic behaviors of CRC cells.

CONCLUSION

Our study revealed that FALEC promoted CRC progression via restoring the expression of miR-2116-3p-targeted PIWIL1, suggesting the potential application of targeting FALEC in the treatment of CRC.

Functional role of the long noncoding RNA X-inactive specific transcript in leiomyoma pathogenesis

OBJECTIVE

To determine the expression and functional roles of a long noncoding RNA (lncRNA) X-inactive specific transcript (XIST) in leiomyoma.

DESIGN

Experimental study.

SETTING

Academic research laboratory.

PATIENT(S)

Women undergoing hysterectomy for leiomyoma.

INTERVENTION(S)

Overexpression and underexpression of XIST; blockade of specific protein 1 (SP1).

MAIN OUTCOME MEASURE(S)

Expression of XIST in leiomyoma and its effects on microRNA 29c (miR-29c), miR-200c, and their targets.

RESULT(S)

Leiomyoma expressed statistically significantly more XIST as compared with matched myometrium, independent of race/ethnicity and menstrual cycle phase. By use of a three-dimensional spheroid culture system, we found reduced XIST levels in leiomyoma smooth muscle cells (LSMC) after treatment with 17β-estradiol, progesterone, and their combination. The expression of XIST was down-regulated by treatment with the SP1-inhibitor mithramycin A and SP1 small interfering RNA. Knockdown of XIST resulted in inhibition of cell proliferation, up-regulation of miR-29c and miR-200c, and a concomitant inhibition of the target genes of these miRNAs, namely collagen type I (COL1A1), collagen type III (COL3A1), and fibronectin (FN1). By contrast, overexpression of XIST in myometrium smooth muscle cells repressed miR-29c and miR-200c, and induced COL1A1, COL3A1, and FN1 levels. By use of RNA immunoprecipitation analysis we confirmed XIST has sponge activity over miR-29c and miR-200c, which is more pronounced in leiomyoma as compared with myometrium.

CONCLUSION(S)

Our data demonstrate that increased expression of XIST in leiomyoma results in reduced expression of miR-29c and miR-200c with a consequent up-regulation of the genes targeted by these microRNAs including COL1A1, COL3A1, and FN1, which play key roles in extracellular matrix accumulation associated with fibroids.

Long noncoding RNA XIST knockdown suppresses the growth of colorectal cancer cells via regulating microRNA-338-3p/PAX5 axis

BACKGROUND

Colorectal cancer is one of the most common human cancers worldwide. Long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) have been reported as the regulators in cancers. The purpose of this study was to reveal the functional mechanisms of lncRNA x inactive specific transcript (XIST) and miR-338-3p in colorectal cancer cells.

METHODS

The transcription level and protein level of genes were assessed by quantitative real-time PCR (qRT-PCR) and western blot assay, respectively. 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay and flow cytometry analysis were used to determine cell proliferation ability and apoptosis rate, respectively. In addition, cell migratory ability and invasive ability were measured using transwell assay. Besides, the interaction between miR-338-3p and XIST or paired box 5 (PAX5) was predicted by starBase or TargetScan and then verified by the dual-luciferase reporter assay.

RESULTS

XIST and PAX5 expression were increased, and miR-338-3p expression was decreased in colorectal cancer tissues and cells. XIST knockdown significantly repressed cell proliferation, migration and invasion, and accelerated apoptosis in colorectal cancer cells. Interestingly, XIST directly downregulated miR-338-3p expression to increase PAX5 level. As expected, XIST knockdown inhibited colorectal cancer cell growth by modulating miR-338-3p expression. Furthermore, miR-338-3p suppressed cell growth via downregulation of PAX5 level in colorectal cancer cells.

CONCLUSION

Our results demonstrated that the downregulation of XIST inhibited cell proliferation, migration and invasion, and induced apoptosis through modulating miR-338-3p/PAX5 axis in colorectal cancer cells, providing potential target for the prevention and treatment of colorectal cancer.

LINC02418 promotes malignant behaviors in lung adenocarcinoma cells by sponging miR-4677-3p to upregulate KNL1 expression

Background

Lung adenocarcinoma (LAD) is a prevalent type of bronchogenic malignant tumor and one of the most critical factors related to human death. Long noncoding RNAs (lncRNAs) are involved in many complex biological processes and have been emerged as extremely important regulators of various cancers. LINC02418, a novel lncRNA, hasn’t been mentioned in previous studies on cancer development. Therefore, it’s important to define the potential function of LINC02418 in LAD.

Methods

Gene expression was examined by RT-qPCR or western blot. CCK-8, colony formation, TUNEL, and transwell assays were utilized to study the role of LINC02418 in LAD. The interaction of miR-4677-3p with LINC02418 (or KNL1) was verified through luciferase reporter, RIP and RNA pull-down assays.

Results

High expression of LINC02418 was observed in LAD specimens and cells. Downregulation of LINC02418 obstructed the proliferation and motility of LAD cells. Moreover, LINC02418 negatively modulated miR-4677-3p expression and miR-4677-3p overexpression could repress cell proliferation and migration. Moreover, kinetochore scaffold 1 (KNL1) expression was negatively modulated by miR-4677-3p but positively regulated by LINC02418. Furthermore, miR-4677-3p could bind with LINC02418 (or KNL1). Finally, KNL1 overexpression reversed the inhibitory function of LINC02418 deficiency in the malignant behaviors of LAD cells.

Conclusions

LINC02418 contributes to the malignancy in LAD via miR-4677-3p/KNL1 signaling, providing a probable therapeutic direction for LAD.

LncRNA XIST Promotes Growth of Human Chordoma Cells by Regulating miR-124-3p/iASPP Pathway

Introduction

Chordoma is a malignant primary bone tumor that is found in the spine and skull. X-inactive specific transcript (XIST) is a long non-coding RNA (lncRNA) is known to be involved in the development of various cancers, but its precise function and mechanism in human chordoma have not been elucidated. Here, we investigated the role of lncRNA XIST in chordoma progression.

Methods

Quantitative real time-polymerase chain reaction (qRT-PCR) was performed to determine lncRNA XIST expression in human chordoma tissues and matched-noncancerous tissues. Western blot was used to determine protein expression. Silencing and overexpression of lncRNA XIST were carried out by RNA interference (RNAi) and lentiviral transduction, respectively. Cell Counting Kit-8 (CCK-8) assay and flow cytometry were employed to examine the effects of lncRNA XIST on growth of human chordoma cells. Lastly, the role of lncRNA XIST in vivo was explored using a xenograft model.

Results

We found that lncRNA XIST expression was upregulated in chordoma and strongly correlated with poor patient prognosis. Moreover, lncRNA XIST promoted proliferation and inhibited apoptosis of chordoma cells. Mechanistically, upregulation of lncRNA XIST led to a decrease in miR-124-3p expression, thereby promoting the expression of the miR-124-3p target gene, inhibitor of apoptosis-stimulating protein of p53 (iASPP). Addition of miR-124-3p inhibitor or mimic reversed the effects induced by lncRNA XIST silencing or overexpression on chordoma cell proliferation. Lastly, using a xenograft mouse model, we found that silencing of lncRNA XIST decreased tumorigenicity in vivo, as shown by increased tumor cell apoptosis.

Conclusion

Our findings demonstrate a key role for lncRNA XIST in chordoma progression by regulating miR124-3p/iAPSS pathway.

Knockdown of the long noncoding RNA XIST suppresses glioma progression by upregulating miR-204-5p

Background: Gliomas are the most prevalent primary malignant tumors of the central nervous system. Our previous study showed that miR-204-5p is a tumor suppressor gene in glioma. Bioinformatic analyses suggest that long noncoding RNA (lncRNA) X-inactive specific transcript (XIST) is a potential target gene of miR-204-5p.

Methods: We analyzed the expression of XIST and miR-204-5p in glioma tissues and the correlation with glioma grade. A series of in vitro experiments were carried out to elucidate the role of XIST in glioma progression. A mouse xenograft model was established to detect whether knockdown of XIST can inhibit glioma growth. A luciferase assay was performed to determine whether XIST can bind to miR-204-5p and the binding specificity. Cells stably expressing shXIST or shNC were transfected with anti-miR-204-5p or anti-miR-204-5p-NC to evaluate whether XIST mediates the tumor-suppressive effects of miR-204-5p.

Results: XIST was upregulated in glioma tissues compared with normal brain tissues (NBTs), while miR-204-5p expression was significantly decreased in glioma tissues compared with NBTs. Both XIST and miR-204-5p expression levels were clearly related to glioma grade, and the expression of XIST was obviously negatively correlated with miR-204-5p expression. Knockdown of XIST inhibited glioma cell proliferation, migration, and invasion, promoted apoptosis of glioma cells, inhibited tumor growth and increased the survival time in nude mice. miR-204-5p could directly bind to XIST and negatively regulate XIST expression. XIST mediated glioma progression by targeting miR-204-5p in glioma cells. XIST crosstalk with miR-204-5p regulated Bcl-2 expression to promote apoptosis.

Conclusion: Our results provide evidence that XIST, miR-204-5p and Bcl-2 form a regulatory axis that controls glioma progression and can serve as a potential therapeutic target for glioma.

Downregulation of XIST ameliorates acute kidney injury by sponging miR-142-5p and targeting PDCD4

Acute kidney injury (AKI) is a common kidney disease that markedly affects public health. To date, the roles of long noncoding RNA XIST in AKI are poorly understood. Here, we investigated the biological functions of XIST in AKI. We observed that XIST expression increased in patients with AKI and HK-2 cells stimulated by CoCl₂ . In addition, a rat AKI model induced by ischemia-reperfusion was established. Tumor necrosis factor-α, interleukin-6, and cyclooxygenase-2 messenger RNA expression were induced in vivo; moreover, XIST expression was upregulated. Knockdown of XIST significantly repressed CoCl₂ -triggered injury in HK-2 cells. However, microRNA (miR)-142-5p, a downstream target of XIST, was downregulated in AKI. miR-142-5p was repressed by XIST and miR-142-5p could inhibit CoCl₂ -induced injury in HK-2 cells. Moreover, PDCD4 expression was significantly increased in AKI. PDCD4 was predicted to be the target of miR-142-5p. Subsequently, loss of PDCD4 was able to retard injury in HK-2 cells exposed to CoCl_2. Thus, we suggest that XIST regulates miR-142-5p and PDCD4, and it has the potential to function as a biomarker in therapeutic strategies for AKI.

Long Non-coding RNA MINCR Regulates miR-876-5p/GSPT1 Axis to Aggravate Glioma Progression

Emerging evidence underlined the crucial roles played by long non-coding RNAs (lncRNAs) in glioma. MINCR has been reported in multiple malignancies. Here, we studied its function and potential mechanism in glioma, which remain unclear. Gene expressions were analyzed by qRT-PCR assay. Both in vitro and in vivo assays were conducted to evaluate the cellular function of MINCR in glioma. The subcellular situation of MINCR was detected by subcellular fractionation and FISH assays. Luciferase reporter, RNA pull-down and RNA immunoprecipitation (RIP) assays were combined to investigate potential mechanisms of relevant genes. MINCR was up-regulated in glioma. MINCR depletion markedly refrained glioma cell proliferation, migration and invasion via sponging miR-876-5p. MiR-876-5p suppressed the malignant behaviors of glioma via binding to GSPT1. MINCR shared the binding sites with the 3'-untranslated region of GSPT1 and prevented the binding of miR-876-5p to GSPT1 mRNA, thus up-regulating the level of GSPT1. Moreover, miR-876 inhibition and GSPT1 up-regulation counteracted the functional effect induced by silencing MINCR on glioma progression. Our findings uncovered that MINCR might aggravated glioma cell proliferation and migration via acting as competing endogenous RNA (ceRNA), indicating prospective novel therapeutic target for glioma.

Long noncoding RNA LINC01234 silencing exerts an anti-oncogenic effect in esophageal cancer cells through microRNA-193a-5p-mediated CCNE1 downregulation

BACKGROUND

Long non-coding RNAs (lncRNAs) are transcribed pervasively in the genome and act to regulate chromatin remodeling and gene expression. Dysregulated lncRNA expression has been reported in many cancers, but the role of lncRNAs in esophageal cancer (EC) has so far remained poorly understood. In this study, we aimed to understand the effect of lncRNA LINC01234 on EC development through competitively binding to microRNA-193a-5p (miR-193a-5p).

METHODS

The Gene Expression Omnibus (GEO) database was used for microarray-based EC expression profiling. Gain- and loss-of-function analyses were carried out in human EC-derived Eca-109 and EC9706 cells. Expression analyses of miR-193a-5p, LINC01234, CCNE1, caspase-3, p21, Bax, cyclinD1 and Bcl-2 were performed using RT-qPCR and Western blotting. Cell proliferation, colony formation and apoptosis analyses were carried out using MTT, Hoechst 33258 and flow cytometry assays. A xenograft EC model in nude mice was used to evaluate in vivo tumor growth and CCNE1 expression.

RESULTS

Microarray-based analyses revealed that LINC01234 expression was increased in primary EC samples, whereas that of miR-193a-5p was decreased. We found that CCNE1 was a target of miR-193a-5p and that LINC01234, in turn, sponges miR-193a-5p. After treatment with si-LINC01234 or miR-193a-5p mimic, EC cells (Eca-109 and EC9706) exhibited cyclinD1 and Bcl-2 downregulation, and caspase-3, p21, Bax and cleaved caspase-3 upregulation. LINC01234 silencing or miR-193a-5p upregulation resulted in decreased proliferation and colony formation, and increased apoptosis of EC cells. In addition, LINC01234 silencing or miR-193a-5p upregulation resulted in reduced in vivo EC tumor growth and CCNE1 expression in nude mice.

CONCLUSIONS

We found that silencing of LINC01234 suppresses EC development by inhibiting CCNE1 through competitively binding to miR-193a-5p, which suggests that LINC01234 may represent a novel target for EC therapy.

XIST promotes cell proliferation and invasion by regulating miR-140-5p and SOX4 in retinoblastoma

Background

Retinoblastoma (RB) is the most common intraocular malignancy in children. Long non-coding RNA X-inactive specific transcript (lncRNA XIST) has been reported to be associated with RB, but research on the mechanism of XIST is not well studied.

Methods

Expressions of XIST, microRNA-140-5p (miR-140-5p), and sex-determining region Y-related high-mobility group box 4 (SOX4) were analyzed by qRT-PCR or Western blot. Relationships of XIST, SOX4, and miR-140-5p were evaluated by dual-luciferase reporter assay and Spearman’s analysis. Cell Counting Kit-8 (CCK-8) and Transwell assay were performed to assess the function of XIST on RB cell proliferation and invasion.

Results

In RB tissues, XIST and SOX4 expressions were obviously increased, but the miR-140-5p expression was markedly reduced. XIST expression was positively related to SOX4 expression while negatively correlated with miR-140-5p expression, and negative correlation was exhibited between miR-140-5p and SOX4 expression in RB tissues. XIST was confirmed to directly bind to miR-140-5p, and SOX4 was one target of miR-140-5p. XIST knockdown could impede RB cell proliferation and invasion, while miR-140-5p inhibition reversed the effects. In addition, XIST overexpression or miR-140-5p inhibition could abrogate the inhibition of SOX4 silencing on cell proliferation and invasion of RB cells.

Conclusions

XIST was obviously increased in RB tissues and cells, and XIST inhibition repressed the proliferation and invasion of RB cells by miR-140-5p/SOX4 axis, which may provide new understandings of the XIST molecular mechanism in RB.

Comprehensive Analysis of Competitive Endogenous RNAs Network, Being Associated With Esophageal Squamous Cell Carcinoma and Its Emerging Role in Head and Neck Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) is a common malignancy with poor prognosis and survival rate. To identify meaningful long non-coding RNA (lncRNA), microRNA (miRNA), and messenger RNA (mRNA) modules related to the ESCC prognosis, The Cancer Genome Atlas-ESCC was downloaded and processed, and then, a weighted gene co-expression network analysis was applied to construct lncRNA co-expression networks, miRNA co-expression networks, and mRNA co-expression networks. Twenty-one hub lncRNAs, seven hub miRNAs, and eight hub mRNAs were clarified. Additionally, a competitive endogenous RNAs network was constructed, and the emerging role of the network involved in head and neck squamous cell carcinoma (HNSCC) was also analyzed using several webtools. The expression levels of eight hub genes (TBC1D2, ATP6V0E1, SPI1, RNASE6, C1QB, C1QC, CSF1R, and C1QA) were different between normal esophageal tissues and HNSCC tissues. The expression levels of TBC1D2 and ATP6V0E1 were related to the survival time of HNSCC. The competitive endogenous RNAs network might provide common mechanisms involving in ESCC and HNSCC. More importantly, useful clues were provided for clinical treatments of both diseases based on novel molecular advances.

Overexpression of the Long Noncoding RNA FOXD2-AS1 Promotes Cisplatin Resistance in Esophageal Squamous Cell Carcinoma Through the miR-195/Akt/mTOR Axis

Emerging evidence has demonstrated that long noncoding RNAs (lncRNAs) mediate the development of esophageal squamous cell carcinoma (ESCC) via various pathophysiological pathways. This study explored the impact of the lncRNA FOXD2-AS1 on cisplatin resistance in ESCC and its possible mechanisms. Upregulation of FOXD2-AS was detected in patients with ESCC and ESCC cells that are resistant to cisplatin. In an in vitro assay, knockdown of FOXD2-AS1 noticeably inhibited cell invasion and growth, triggered cell death, and repressed the stimulation of the Akt/mTOR axis in cisplatin-resistant ESCC cells (TE-1/DDP). Conversely, the overexpression of FOXD2-AS1 remarkably increased cell invasion and growth, repressed cell death, and triggered the stimulation of the Akt/mTOR axis in TE-1/DDP cells. These findings, along with bioinformatics and validation tests, showed that FOXD2-AS1 targeted miR-195 by acting as a competing endogenous RNA. FOXD2-AS1/miR-195/Akt/mTOR axis plays a crucial role in resistance to cisplatin in ESCC cells, offering an innovative strategy to treat ESCC.

Downregulated lncRNA UCA1 acts as ceRNA to adsorb microRNA-498 to repress proliferation, invasion and epithelial mesenchymal transition of esophageal cancer cells by decreasing ZEB2 expression

Objective: Esophageal cancer (EC) is one of the most general malignant tumors in humans. There were few studies researching the connections between lncRNA UCA1 and EC. This study is to research the effect of lncRNA UCA1 adsorbing microRNA-498 (miR-498) as a ceRNA to regulate ZEB2 expression on epithelial mesenchymal transition (EMT), invasion and migration of EC cells. Methods: UCA1, miR-498 and ZEB2 expression in EC tissues and cells was detected by RT-qPCR or western blot analysis. EC cells were transfected with siRNA-UCA1, miR-498 mimics or their controls to determine cell colony, proliferation, cycle distribution, apoptosis, migration and invasion by colony formation assay, CCK-8 assay, flow cytometry, and Transwell assay, respectively. The protein expression of PCNA, c-Myc, E-cadherin, N-cadherin, MMP-2 and MMP-9 was detected by Western blot analysis. The growth rate and weight of transplanted tumor in nude mice were observed. Results: There were overly expressed UCA1 and ZEB2 and lowly expressed miR-498 in EC tissues and cells. LncRNA UCA1 acted as ceRNA to inhibit miR-498 expression and thereby increasing ZEB2 expression. With down-regulated UCA1 and up-regulated miR-498, ZEB2 expression, cell proliferation, colony formation, invasion, migration ability, EMT, tumor growth rate and weight in nude mice were apparently reduced. Conclusion: This study demonstrates that inhibited UCA1 up-regulated miR-498 and down-regulated ZEB2, thereby repressing proliferation activity, invasion, migration, and EMT of EC cells.