Long non-coding RNA XIST regulates gastric cancer progression by acting as a molecular sponge of miR-101 to modulate EZH2 expression

Circulating long noncoding RNA, Zfpm2-As1, and XIST based on medical data analysis are potential plasma biomarkers for gastric cancer diagnosis

BACKGROUND

Long noncoding RNAs (lncRNAs) participate in diseases, especially tumorigenesis, including gastric cancer (GC). Although lncRNAs in GC tissues have been extensively studied in previous research, the possible significance of circulating lncRNAs in diagnosing GC is still unknown.

OBJECTIVE

The present work investigated lncRNAs ZFPM2-AS1 and XIST with high expression in GC tissues proved as potential plasma biomarkers from 20 early GC cases, 100 GC cases, and 90 normal subjects.

METHODS

The possible correlation between ZFPM2-AS1 and XIST expression levels was analyzed with general characteristics and clinicopathological features. The performance in diagnosis was assessed according to receiver operating characteristic (ROC) analysis.

RESULTS

According to the results, XIST and ZFPM2-AS1 expression remarkably increased within GC plasma relative to normal subjects (P< 0.01); besides, lncRNA XIST expression after surgery had a tendency of downregulation compared with preoperative levels (P< 0.05). Moreover, the area under ROC curve (AUC) values were 0.62 for ZFPM2-AS1 and 0.68 for XIST, while the pooled AUC value of CA-724 and two lncRNAs was 0.751.

CONCLUSION

Circulating lncRNAs ZFPM2-AS1 and XIST can serve as the candidate plasma biomarkers used to diagnose GC.

Dysregulation of the Long Non-coding RNA Xist Expression in Male Patients with Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a sex-biased disease with female gender as a significant risk factor. Recently, we reported that increased expression of the long non-coding (lnc)RNA Xist, as induced by an intersectin-1s protein fragment with proliferative potential (EHITSN), may explain the sexual dimorphism of female pulmonary artery endothelial cells (ECs) and at least in part, the imbalance sex/ratio of PAH. Xist is essential for X-chromosome inactivation and dosage compensation of X-linked genes. Increased Xist expression was also detected in a subset of ECs and lung tissue samples of male PAH patients. The role of different Xist expression levels in ECs of male PAH patients (ECPAH) was studied in several lines of male ECPAH in conjunction with molecular, biochemical, morphological, and functional approaches. Male ECPAH showed on average 10.3-fold increase in high Xist vs. low Xist, a significant association between Xist levels and their proliferative potential, and a heterogeneous methylation of the Xist/Tsix locus. Interestingly, Xist up-regulation in male ECPAH decreases the expression of Klf2, via EHITSN interaction with EZH2, the catalytic subunit of the polycomb repressive complex 2. Moreover, the studies demonstrate that EHITSN-triggered p38/Elk1/c-Fos signaling is a pathological mechanism central to ECPAH proliferation and the dynamic crosstalk with cell cycle regulatory proteins ccna1/ccnd2, and Xist-EZH2-Klf2 interaction participate directly and differentially in establishing the proliferative profile of male ECPAH.

EZH2-interacting lncRNAs contribute to gastric tumorigenesis; a review on the mechanisms of action

Gastric cancer (GC) remains one of the deadliest malignancies worldwide, demanding new targets to improve its diagnosis and treatment. Long non-coding RNAs (lncRNAs) are dysregulated through gastric tumorigenesis and play a significant role in GC progression and development. Recent studies have revealed that lncRNAs can interact with histone-modifying polycomb protein, enhance Zeste Homolog 2 (EZH2), and mediate its site-specific functioning. EZH2, which functions as an oncogene in GC, is the catalytic subunit of the PRC2 complex that induces H3K27 trimethylation and epigenetically represses gene expression. EZH2-interacting lncRNAs can recruit EZH2 to the promoter regions of various tumor suppressor genes and cause their transcriptional deactivation via histone methylation. The interactions between EZH2 and this lncRNA modulate different processes, such as cell cycle, cell proliferation and growth, migration, invasion, metastasis, and drug resistance, in vitro and in vivo GC models. Therefore, EZH2-interacting lncRNAs are exciting targets for developing novel targeted therapies for GC. Subsequently, this review aims to focus on the roles of these interactions in GC progression to understand the therapeutic value of EZH2-interacting lncRNAs further.

LncRNA PRKCA-AS1 promotes LUAD progression and function as a ceRNA to regulate S100A16 by sponging miR-508-5p

Objective: This study aimed to elucidate the underlying mechanism of LncRNA PRKCA-AS1 in lung adenocarcinoma (LUAD). Methods: The expression of LncRNA PRKCA-AS1, miR-508-5p and S100A16, in LUAD tissues or cell lines (NCI-H520 and H1299) was analyzed with qRT-PCR. The clinical diagnostic value of LncRNA PRKCAAS1, miR-508-5p and S100A16 in LUAD were analyzed by receptor operating characteristic (ROC) curve. Then we knockdown or overexpression of PRKCAAS1 in NCI-H520 and H1299 cells, and the cell function test was applied to detect the activity and metastasis level of cells in different transfection groups. Then Pearson correlation analysis was used for the correlation between miR-508-5p and PRKCA-AS1. The dual-luciferase reporter experiment and CHIRP analysis was conducted to verify the target binding relationship of PRKCA-AS1, miR-508-5p or S100A16. FISH assay analyzed the colocalization of PRKCA-AS1 and miR-508-5p in NCI-H520 and H1299 cells. Rescue experiment and tumorigenesis experiment in nude mice further explore the regulatory mechanisms of LncRNA PRKCA-AS1, miR-508-5p and S100A16 on LUAD progression in vitro and in vivo. Results: From the results, PRKCA-AS1 and S100A16 were up-regulated in LUAD tissues, while miR-508-5p was downregulated compared with the adjacent tissues. And gain-of-function revealed that PRKCA-AS1 knock-down apparently suppressed the cell proliferation and metastasis, whereas miR-508-5p inhibitors or S100A16 overexpression showed a opposite effect. In addition, there is evidence that PRKCA-AS1, miR-508-5p and S100A16 have a targeted regulatory relationship. Moreover, rescue experiment and tumorigenesis experiment in nude mice further confirmed that LncRNA PRKCA-AS1 regulates S100A16 through sponging miR-508-5p to regulate LUAD progression in vitro and in vivo. Conclusion: These results demonstrated that LncRNA PRKCA-AS1 might regulate LUAD by acting as a ceRNA via sponging miR-508-5p and regulating S100A16 expression, indicating that manipulation of PRKCA-AS1 might be a potential therapeutic strategy in LUAD.

Targeting long non-coding RNAs in cancer therapy using CRISPR-Cas9 technology: A novel paradigm for precision oncology

Cancer is the second leading cause of death worldwide, despite recent advances in its identification and management. To improve cancer patient diagnosis and care, it is necessary to identify new biomarkers and molecular targets. In recent years, long non-coding RNAs (lncRNAs) have surfaced as important contributors to various cellular activities, with growing proof indicating their substantial role in the genesis, development, and spread of cancer. Their unique expression profiles within specific tissues and their wide-ranging functionalities make lncRNAs excellent candidates for potential therapeutic intervention in cancer management. They are implicated in multiple hallmarks of cancer, such as uncontrolled proliferation, angiogenesis, and immune evasion. This review article explores the innovative application of CRISPR-Cas9 technology in targeting lncRNAs as a cancer therapeutic strategy. The CRISPR-Cas9 system has been widely applied in functional genomics, gene therapy, and cancer research, offering a versatile platform for lncRNA targeting. CRISPR-Cas9-mediated targeting of lncRNAs can be achieved through CRISPR interference, activation or the complete knockout of lncRNA loci. Combining CRISPR-Cas9 technology with high-throughput functional genomics makes it possible to identify lncRNAs critical for the survival of specific cancer subtypes, opening the door for tailored treatments and personalised cancer therapies. CRISPR-Cas9-mediated lncRNA targeting with other cutting-edge cancer therapies, such as immunotherapy and targeted molecular therapeutics can be used to overcome the drug resistance in cancer. The synergy of lncRNA research and CRISPR-Cas9 technology presents immense potential for individualized cancer treatment, offering renewed hope in the battle against this disease.

Expression, Functional Polymorphism, and Diagnostic Values of MIAT rs2331291 and H19 rs217727 Long Non-Coding RNAs in Cerebral Ischemic Stroke Egyptian Patients

Cerebral ischemic stroke (CIS) is a severe cerebral vascular event. This research aimed to evaluate the role of single-nucleotide polymorphisms (SNPs) of the lncRNAs MIAT rs2331291 and H19 rs217727 and epigenetic methylation in the expression patterns of serum lncRNA H19 in CIS Egyptian patients. It included 80 CIS cases and 40 healthy subjects. Serum MIAT expression levels decreased, whereas serum H19 expression levels increased among CIS compared to controls. For MIAT rs2331291, there were significant differences in the genotypic and allelic frequencies between the CIS and healthy subjects at p = 0.02 and p = 0.0001, respectively. Our findings illustrated a significantly increased MIAT T/T genotype frequency in hypertensive CIS compared to non-hypertensive CIS at p = 0.004. However, H19 rs217727 gene frequency C/C was not significantly higher in non-hypertensive CIS than in hypertensive CIS. The methylation of the H19 gene promoter was significantly higher in CIS patients compared to healthy subjects. The level of MIAT was positively correlated with serum H19 in CIS. Receiver operating characteristics (ROC) analysis revealed that serum MIAT and H19 have a high diagnostic potential for distinguishing CIS subjects from healthy ones. In conclusion, the MIAT-rs2331291 polymorphism might serve as a novel potential indicator of CIS.

Epigenome editing in cancer: Advances and challenges for potential therapeutic options

Cancers are diseases caused by genetic and non-genetic environmental factors. Epigenetic alterations, some attributed to non-genetic factors, can lead to cancer development. Epigenetic changes can occur in tumor suppressors or oncogenes, or they may contribute to global cell state changes, making cells abnormal. Recent advances in gene editing technology show potential for cancer treatment. Herein, we will discuss our current knowledge of epigenetic alterations occurring in cancer and epigenetic editing technologies that can be applied to developing therapeutic options.

Role of non-coding RNAs as new therapeutic targets in regulating the EMT and apoptosis in metastatic gastric and colorectal cancers

Colorectal cancer (CRC) and gastric cancer (GC), are the two most common cancers of the gastrointestinal tract, and are serious health concerns worldwide. The discovery of more effective biomarkers for early diagnosis, and improved patient prognosis is important. Non-coding RNAs (ncRNAs), including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), can regulate cellular processes such as apoptosis and the epithelial-mesenchymal transition (EMT) leading to progression and resistance of GC and CRC tumors. Moreover these pathways (apoptosis and EMT) may serve as therapeutic targets, to prevent metastasis, and to overcome drug resistance. A subgroup of ncRNAs is common to both GC and CRC tumors, suggesting that they might be used as biomarkers or therapeutic targets. In this review, we highlight some ncRNAs that can regulate EMT and apoptosis as two opposite mechanisms in cancer progression and metastasis in GC and CRC. A better understanding of the biological role of ncRNAs could open up new avenues for the development of personalized treatment plans for GC and CRC patients.

Integrated bioinformatics analysis of noncoding RNAs with tumor immune microenvironment in gastric cancer

In recent years, molecular and genetic research hotspots of gastric cancer have been investigated, including microRNAs, long noncoding RNAs (lncRNAs) and messenger RNA (mRNAs). The study on the role of lncRNAs may help to develop personalized treatment and identify potential prognostic biomarkers in gastric cancer. The RNA-seq and miRNA-seq data of gastric cancer were downloaded from the TCGA database. Differential analysis of RNA expression between gastric cancer samples and normal samples was performed using the edgeR package. The ceRNA regulatory network was visualized using Cytoscape. KEGG pathway analysis of mRNAs in the ceRNA network was performed using the clusterProfiler package. CIBERSORT was used to distinguish 22 immune cell types and the prognosis-related genes and immune cells were determined using Kaplan-Meier and Cox proportional hazard analyses. To estimate these nomograms, we used receiver operating characteristic and calibration curve studies. The ceRNA regulation network of gastric cancer was built in this study, and the genes in the network were analyzed for prognosis. A total of 980 lncRNAs were differentially expressed, of which 774 were upregulated and 206 were downregulated. A survival study identified 15 genes associated with gastric cancer prognosis, including VCAN-AS1, SERPINE1, AL139002.1, LINC00326, AC018781.1, C15orf54, hsa-miR-145. Monocytes and Neutrophils were associated with the survival rate of gastric cancer. Our research uncovers new ceRNA network for the detection, treatment, and monitoring of gastric cancer.

LINC01268 promotes epithelial-mesenchymal transition, invasion and metastasis of gastric cancer via the PI3K/Akt signaling pathway and targeting MARCKS

BACKGROUND

Long non-coding RNAs (lncRNAs) with differential expression characteristics have been found to be closely related to the tumorigenesis and development of gastric cancer (GC), but their specific mechanisms and roles still need to be further elucidated.

AIM

To investigate the expression of LINC01268 in GC and its mechanism of affecting GC progression.

METHODS

Real-time quantitative polymerase chain reaction was used to detect the expression of LINC01268 in GC tissues, cell lines and plasma. The Kaplan-Meier method was used to evaluate the value of LINC01268 in the prognostication of GC patients. An receiver operating characteristic curve was constructed to evaluate the value of LINC01268 in the diagnosis of GC. Transwell migration and invasion assays and wound healing assays were used to confirm the effect of LINC01268 on the invasion and migration of GC cells. The regulatory relationship between LINC01268 and myristoylated alanine rich protein kinase C substrate (MARCKS), the PI3K/Akt signaling pathway, and the epithelial-mesenchymal transition (EMT) process in GC was demonstrated by western blot analysis.

RESULTS

The expression of LINC01268 was increased in GC tissues and cell lines. The expression level of LINC01268 was significantly correlated with lymph node metastasis, TNM stage, and tumor differentiation in patients with GC. Over-expression of LINC01268 indicated a poor prognosis for patients with GC, and it had a certain auxiliary diagnostic value for GC. In vitro functional experiments proved that the abnormal expression of LINC01268 further activated the PI3K/Akt signaling pathway and promoted EMT by targeting and regulating MARCKS and ultimately promoted the invasion and metastasis of GC.

CONCLUSION

This study elucidates that LINC01268 in GC may be an oncogene that further activates the PI3K/Akt signaling pathway and EMT by targeting and regulating MARCKS, and ultimately promotes the invasion and metastasis of GC. LINC01268 may be a potential effective target for the treatment of GC.

Prognostic Implication of Plasma Metabolites in Gastric Cancer

Gastric cancer (GC) typically carries a poor prognosis as it is often diagnosed at a late stage. Altered metabolism has been found to impact cancer outcomes and affect patients' quality of life, and the role of metabolites in gastric cancer prognosis has not been sufficiently understood. We aimed to establish a prognostic prediction model for GC patients based on a metabolism-associated signature and identify the unique role of metabolites in the prognosis of GC. Thus, we conducted untargeted metabolomics to detect the plasma metabolites of 218 patients with gastric adenocarcinoma and explored the metabolites related to the survival of patients with gastric cancer. Firstly, we divided patients into two groups based on the cutoff value of the abundance of each of the 60 metabolites and compared the differences using Kaplan-Meier (K-M) survival analysis. As a result, 23 metabolites associated with gastric cancer survival were identified. To establish a risk score model, we performed LASSO regression and Cox regression analysis on the 60 metabolites and identified 8 metabolites as an independent prognostic factor. Furthermore, a nomogram incorporating clinical parameters and the metabolic signature was constructed to help individualize outcome predictions. The results of the ROC curve and nomogram plot showed good predictive performance of metabolic risk features. Finally, we performed pathway analysis on the 24 metabolites identified in the two parts, and the results indicated that purine metabolism and arachidonic acid metabolism play important roles in gastric cancer prognosis. Our study highlights the important role of metabolites in the progression of gastric cancer and newly identified metabolites could be potential biomarkers or therapeutic targets for gastric cancer patients.

LncRNA MIR155HG Overexpression Promotes Proliferation, Migration, and Chemoresistance in Gastric Cancer Cells

Long non-coding RNAs are thought to play a vital role in a variety of human malignancies. Studies have shown that MIR155 host gene (MIR155HG) acts as an oncogene in several cancers, but the function and its mechanism of MIR155HG in gastric cancer (GC) is still poorly understood. In this study, we determined the biological functions and underlying mechanisms of MIR155HG in GC cells. We found that expression levels of MIR155HG was increased markedly in GC patients' serum. In vitro and in vivo studies demonstrated that MIR155HG modulated the malignant phenotype of GC cells, such as cell proliferation, colony forming ability, cell migration ability, and tumor growth in nude mice. Next, our results revealed that NF-κB and STAT3 signaling pathways could be involved in regulating the malignant behavior of GC cells. Our rescue experiments showed that inhibiting NF-κB and STAT3 signaling pathways attenuated the phenotypes caused by MIR155HG overexpression. Moreover, cytotoxicity and apoptosis assays revealed overexpression of MIR155HG reduced the apotosis of GC cells induced by cisplatin and 5-FU. Together, our studies suggested that MIR155HG overexpression promoted proliferation, migration, and chemoresistance of GC cells. These results might provide a lncRNA-based target for GC treatment in future.

Potential roles of lncRNA-XIST/miRNAs/mRNAs in human cancer cells

Long non-coding RNAs (lncRNAs) are non-coding RNAs that contain more than 200 nucleotides but do not code for proteins. In tumorigenesis, lncRNAs can have both oncogenic and tumor-suppressive properties. X inactive-specific transcript (XIST) is a known lncRNA that has been implicated in X chromosome silencing in female cells. Dysregulation of XIST is associated with an increased risk of various cancers. Therefore, XIST can be a beneficial prognostic biomarker for human malignancies. In this review, we attempt to summarize the emerging roles of XIST in human cancers.

Long Non-Coding RNAs as Novel Targets for Phytochemicals to Cease Cancer Metastasis

Metastasis is a multi-step phenomenon during cancer development leading to the propagation of cancer cells to distant organ(s). According to estimations, metastasis results in over 90% of cancer-associated death around the globe. Long non-coding RNAs (LncRNAs) are a group of regulatory RNA molecules more than 200 base pairs in length. The main regulatory activity of these molecules is the modulation of gene expression. They have been reported to affect different stages of cancer development including proliferation, apoptosis, migration, invasion, and metastasis. An increasing number of medical data reports indicate the probable function of LncRNAs in the metastatic spread of different cancers. Phytochemical compounds, as the bioactive agents of plants, show several health benefits with a variety of biological activities. Several phytochemicals have been demonstrated to target LncRNAs to defeat cancer. This review article briefly describes the metastasis steps, summarizes data on some well-established LncRNAs with a role in metastasis, and identifies the phytochemicals with an ability to suppress cancer metastasis by targeting LncRNAs.

The roles of long non‑coding RNAs in renal cell carcinoma (Review)

Long non-coding RNAs (lncRNAs) are involved in the gene expression regulation and usually play important roles in various human cancers, including the renal cell carcinoma (RCC). Dysregulation of certain lncRNAs are associated with the prognosis of patients with RCC. In the present review, several recently studied lncRNAs were discussed and their critical roles in proliferation, migration, invasion, apoptosis and drug resistance of renal cancer cells were revealed. The research on lncRNAs further increases our understanding on the development and progression of RCC. It is suggested that lncRNAs can be used as biomarkers or therapeutic targets for diagnosis or treatment of renal cancer.

Epigenetic regulation in myocardial infarction: Non-coding RNAs and exosomal non-coding RNAs

Myocardial infarction (MI) is one of the leading causes of deaths globally. The early diagnosis of MI lowers the rate of subsequent complications and maximizes the benefits of cardiovascular interventions. Many efforts have been made to explore new therapeutic targets for MI, and the therapeutic potential of non-coding RNAs (ncRNAs) is one good example. NcRNAs are a group of RNAs with many different subgroups, but they are not translated into proteins. MicroRNAs (miRNAs) are the most studied type of ncRNAs, and have been found to regulate several pathological processes in MI, including cardiomyocyte inflammation, apoptosis, angiogenesis, and fibrosis. These processes can also be modulated by circular RNAs and long ncRNAs via different mechanisms. However, the regulatory role of ncRNAs and their underlying mechanisms in MI are underexplored. Exosomes play a crucial role in communication between cells, and can affect both homeostasis and disease conditions. Exosomal ncRNAs have been shown to affect many biological functions. Tissue-specific changes in exosomal ncRNAs contribute to aging, tissue dysfunction, and human diseases. Here we provide a comprehensive review of recent findings on epigenetic changes in cardiovascular diseases as well as the role of ncRNAs and exosomal ncRNAs in MI, focusing on their function, diagnostic and prognostic significance.

Polycomb Directed Cell Fate Decisions in Development and Cancer

The polycomb group (PcG) proteins are a subset of transcription regulators highly conserved throughout evolution. Their principal role is to epigenetically modify chromatin landscapes and control the expression of master transcriptional programs to determine cellular identity. The two mayor PcG protein complexes that have been identified in mammals to date are Polycomb Repressive Complex 1 (PRC1) and 2 (PRC2). These protein complexes selectively repress gene expression via the induction of covalent post-translational histone modifications, promoting chromatin structure stabilization. PRC2 catalyzes the histone H3 methylation at lysine 27 (H3K27me1/2/3), inducing heterochromatin structures. This activity is controlled by the formation of a multi-subunit complex, which includes enhancer of zeste (EZH2), embryonic ectoderm development protein (EED), and suppressor of zeste 12 (SUZ12). This review will summarize the latest insights into how PRC2 in mammalian cells regulates transcription to orchestrate the temporal and tissue-specific expression of genes to determine cell identity and cell-fate decisions. We will specifically describe how PRC2 dysregulation in different cell types can promote phenotypic plasticity and/or non-mutational epigenetic reprogramming, inducing the development of highly aggressive epithelial neuroendocrine carcinomas, including prostate, small cell lung, and Merkel cell cancer. With this, EZH2 has emerged as an important actionable therapeutic target in such cancers.

Extracellular vesicle expansion of PMIS-miR-210 expression inhibits colorectal tumour growth via apoptosis and an XIST/NME1 regulatory mechanism

BACKGROUND

Colorectal cancer (CRC) has a high mortality rate, and therapeutic approaches to treat these cancers are varied and depend on the metabolic state of the tumour. Profiles of CRC tumours have identified several biomarkers, including microRNAs. microRNA-210 (miR-210) levels are directly correlated with CRC survival. miR-210 expression is higher in metastatic colon cancer cells versus non-metastatic and normal colon epithelium. Therefore, efficient methods to inhibit miR-210 expression in CRC may provide new advances in treatments.

METHODS

Expression of miRs was determined in several metastatic and non-metastatic cell lines. miR-210 expression was inhibited using PMIS-miR-210 in transduced cells, which were transplanted into xenograft mice. In separate experiments, CRC tumours were allowed to grow in xenograft mice and treated with therapeutic injections of PMIS-miR-210. Molecular and biochemical experiments identified several new pathways targeted by miR-210 inhibition.

RESULTS

miR-210 inhibition can significantly reduce tumour growth of implanted colon cancer cells in xenograft mouse models. The direct administration of PMIS-miR-210 to existing tumours can inhibit tumour growth in both NSG and Foxn1nu/j mouse models and is more efficacious than capecitabine treatments. Tumour cells further transfer the PMIS-miR-210 inhibitor to neighbouring cells by extracellular vesicles to inhibit miR-210 throughout the tumour. miR-210 inhibition activates the cleaved caspase 3 apoptotic pathway to reduce tumour formation. We demonstrate that the long non-coding transcript XIST is regulated by miR-210 correlating with decreased XIST expression in CRC tumours. XIST acts as a competing endogenous RNA for miR-210, which reduces XIST levels and miR-210 inhibition increases XIST transcripts in the nucleus and cytoplasm. The increased expression of NME1 is associated with H3K4me3 and H3K27ac modifications in the NME1 proximal promoter by XIST.

CONCLUSION

Direct application of the PMIS-miR-210 inhibitor to growing tumours may be an effective colorectal cancer therapeutic.

LncRNA CCAT1 Upregulates ATG5 to Enhance Autophagy and Promote Gastric Cancer Development by Absorbing miR-140-3p

BACKGROUND

Long noncoding RNA colon cancer-associated transcript 1 (LncRNA CCAT1) is highly expressed in gastric cancer tissues and plays a role in autophagy. However, the underlying mechanism still needs to be further clarified.

OBJECTIVE

To study the role of LncRNA CCAT1 in regulating autophagy of gastric cancer cells, analyze its downstream targets, and elucidate the mechanism.

METHODS

qPCR detected the expression of LncRNA CCAT1 in gastric cancer cells. The proliferation, migration, and invasion ability of LncRNA CCAT1 and the expression level of autophagy-related proteins in gastric cancer cells were detected. Bioinformatics method predicted the downstream targets of LncRNA CCAT1, and they were verified by dual-luciferase assay. The relationship between LncRNA CCAT1, miR-140, and ATG5 was verified by co-transfection, and the expression levels of ATG5 and ATG5-ATG12 complex proteins were detected. Finally, the role of LncRNA CCAT1 in vivo was confirmed by gastric cancer transplantation model.

RESULTS

LncRNA CCAT1 was highly expressed in gastric cancer cells. LncRNA CCAT1 can promote the proliferation, migration, invasion, and autophagy activity of gastric cancer cells. LncRNA CCAT1 can bind to miR-140-3p and regulate its expression, while miR-140-3p further regulates the expression of ATG5. Overexpression of LncRNA CCAT1 can promote tumor growth in nude mice. After LncRNA CCAT1 silencing, the positive expression rate of ATG5 in nude mice was low.

CONCLUSION

LncRNA CCAT1 may inhibit the expression of miR-140-3p by sponge adsorption, thus weakening its inhibitory effect on ATG5. Eventually, gastric cancer cells were more prone to autophagy under the pressure of stress.

Long Noncoding RNA and Circular RNA: Two Rising Stars in Regulating Epithelial-Mesenchymal Transition of Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant tumor with especially poor prognosis. However, the molecular mechanisms of pancreatic oncogenesis and malignant progression are not fully elucidated. Epithelial-mesenchymal transition (EMT) process is important to drive pancreatic carcinogenesis. Recently, long noncoding RNAs (lncRNAs) and circular RNAs(circRNAs) have been characterized to participate in EMT in PDAC, which can affect the migration and invasion of tumor cells by playing important roles in epigenetic processes, transcription, and post-transcriptional regulation. LncRNAs can act as competing endogenous RNAs (ceRNA) to sequester target microRNAs(miRNAs), bind to the genes which localize physically nearby, and directly interact with EMT-related proteins. Currently known circRNAs mostly regulate the EMT process in PDAC also by acting as a miRNA sponge, directly affecting the protein degradation process. Therefore, exploring the functions of lncRNAs and circRNAs in EMT during pancreatic cancer might help pancreatic cancer treatments.

The role of lncRNA-mediated ceRNA regulatory networks in pancreatic cancer

Non-coding RNAs (ncRNAs), which occupy the vast majority of human transcripts are known for their inability to encode proteins. NcRNAs consist of a diverse range of RNA species, including long non-coding RNAs (lncRNAs), which have significant meaning for epigenetic modification, post-transcriptional regulation of target genes, molecular interference, etc. The dysregulation of ncRNAs will mediate the pathogenesis of diverse human diseases, like cancer. Pancreatic cancer, as one of the most lethal malignancies in the digestive system that is hard to make a definite diagnosis at an early clinicopathological stage with a miserable prognosis. Therefore, the identification of potential and clinically applicable biomarker is momentous to improve the overall survival rate and positively ameliorate the prognosis of patients with pancreatic carcinoma. LncRNAs as one kind of ncRNAs exert multitudinous biological functions, and act as molecular sponges, relying on microRNA response elements (MREs) to competitively target microRNAs (miRNAs), thereby attenuating the degradation or inhibition of miRNAs to their own downstream protein-coding target genes, also thus regulating the initiation and progression of neoplasms. LncRNAs, which emerge aforementioned function are called competing endogenous RNAs (ceRNAs). Consequently, abundant research of lncRNAs as potential biomarkers is of critical significance for the molecular diagnosis, targeted therapy, as well as prognosis monitoring of pancreatic cancer.

Long non-coding RNA-X-inactive specific transcript inhibits cell viability, and induces apoptosis through the microRNA-30c-5p/Bcl2-like protein 11 signaling axis in human granulosa-like tumor cells

The role of long noncoding RNAs (lncRNAs) is being actively explored in polycystic ovary syndrome (PCOS). Recent research has shown that long non-coding RNA (lncRNA) X–inactive Specific Transcript (XIST) is overexpressed in patients with PCOS and is associated with poor pregnancy outcomes. However, the precise function and mechanism of action of lncRNA XIST in PCOS are unknown. We aimed to determine whether lncRNA XIST contributes to PCOS by modulating ovarian granulosa cell physiology. We also investigated any potential molecular regulatory mechanisms. In this study, we discovered that the lncRNA XIST was significantly downregulated in human ovarian granulosa-like tumor (KGN) cells. Notably, overexpression of lncRNA XIST decreased miR-30c-5p expression in KGN cells, inhibited proliferation, and induced apoptosis in KGN cells. However, cotransfection with amiR-30c-5p mimic significantly reduced these effects. Additionally, we discovered that the miR-30c-5p mimic effectively inhibited Bcl2-like protein 11 (BCL2L11) expression, a critical apoptotic promoter, whereas silencing of miR-30c-5p increased BCL2L11 expression, inhibited KGN cell proliferation, and induced apoptosis. In contrast, cotransfection of BCL2L11 with siRNA significantly reversed these effects. In conclusion, this study established that lncRNA XIST plays a critical role in PCOS by modulating the miR-30c-5p/BCL2L11 signaling axis and regulating ovarian granulosa cell physiology.

Long Non-Coding RNAs in Pancreatic Cancer: Biologic Functions, Mechanisms, and Clinical Significance

Despite tremendous efforts devoted to research in pancreatic cancer (PC), the mechanism underlying the tumorigenesis and progression of PC is still not completely clear. Additionally, ideal biomarkers and satisfactory therapeutic strategies for clinical application in PC are still lacking. Accumulating evidence suggests that long non-coding RNAs (lncRNAs) might participate in the pathogenesis of diverse cancers, including PC. The abnormal expression of lncRNAs in PC is considered a vital factor during tumorigenesis that affects tumor cell proliferation, migration, invasion, apoptosis, angiogenesis, and drug resistance. With this review of relevant articles published in recent years, we aimed to summarize the biogenesis mechanism, classifications, and modes of action of lncRNAs and to review the functions and mechanisms of lncRNAs in PC. Additionally, the clinical significance of lncRNAs in PC was discussed. Finally, we pointed out the questions remaining from recent studies and anticipated that further investigations would address these gaps in knowledge in this field.

Major Role for Cellular MicroRNAs, Long Noncoding RNAs (lncRNAs), and the Epstein-Barr Virus-Encoded BART lncRNA during Tumor Growth In Vivo

This study assessed the effects of Epstein-Barr virus (EBV) and one form of virally encoded BART long noncoding RNAs (lncRNAs) on cellular expression in epithelial cells grown in vitro and as tumors in vivo determined by high-throughput RNA sequencing of mRNA and small RNAs. Hierarchical clustering based on gene expression distinguished the cell lines from the tumors and distinguished the EBV-positive tumors and the BART tumors from the EBV-negative tumors. EBV and BART expression also induced specific expression changes in cellular microRNAs (miRs) and lncRNAs. Multiple known and predicted targets of the viral miRs, the induced cellular miRs, and lncRNAs were identified in the altered gene set. The changes in expression in vivo indicated that the suppression of growth pathways in vivo reflects increased expression of cellular miRs in all tumors. In the EBV and BART tumors, many of the targets of the induced miRs were not changed and the seed sequences of the nonfunctional miRs were found to have homologous regions within the BART lncRNA. The inhibition of these miR effects on known targets suggests that these induced miRs have reduced function due to sponging by the BART lncRNA. This composite analysis identified the effects of EBV on cellular miRs and lncRNAs with a functional readout through identification of the simultaneous effects on gene expression. Major shifts in gene expression in vivo are likely mediated by effects on cellular noncoding RNAs. Additionally, a predicted property of the BART lncRNA is to functionally inhibit the induced cellular miRs.

A Boolean Model of the Proliferative Role of the lncRNA XIST in Non-Small Cell Lung Cancer Cells

The long non-coding RNA X inactivate-specific transcript (lncRNA XIST) has been verified as an oncogenic gene in non-small cell lung cancer (NSCLC) whose regulatory role is largely unknown. The important tumor suppressors, microRNAs: miR-449a and miR-16 are regulated by lncRNA XIST in NSCLC, these miRNAs share numerous common targets and experimental evidence suggests that they synergistically regulate the cell-fate regulation of NSCLC. LncRNA XIST is known to sponge miR-449a and miR-34a, however, the regulatory network connecting all these non-coding RNAs is still unknown. Here we propose a Boolean regulatory network for the G1/S cell cycle checkpoint in NSCLC contemplating the involvement of these non-coding RNAs. Model verification was conducted by comparison with experimental knowledge from NSCLC showing good agreement. The results suggest that miR-449a regulates miR-16 and p21 activity by targeting HDAC1, c-Myc, and the lncRNA XIST. Furthermore, our circuit perturbation simulations show that five circuits are involved in cell fate determination between senescence and apoptosis. The model thus allows pinpointing the direct cell fate mechanisms of NSCLC. Therefore, our results support that lncRNA XIST is an attractive target of drug development in tumor growth and aggressive proliferation of NSCLC, and promising results can be achieved through tumor suppressor miRNAs.

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.

The Biology and Function of Extracellular Vesicles in Cancer Development

Extracellular vesicles (EVs) exert their biological functions by delivering proteins, metabolites, and nucleic acids to recipient cells. EVs play important roles in cancer development. The anti-tumor effect of EVs is by their cargos carrying proteins, metabolites, and nucleic acids to affect cell-to-cell communication. The characteristics of cell-to-cell communication can potentially be applied for the therapy of cancers, such as gastric cancer. In addition, EVs can be used as an effective cargos to deliver ncRNAs, peptides, and drugs, to target tumor tissues. In addition, EVs have the ability to regulate cell apoptosis, autophagy, proliferation, and migration of cancer cells. The ncRNA and peptides that were engaged with EVs were associated with cell signaling pathways in cancer development. This review focuses on the composition, cargo, function, mechanism, and application of EVs in cancers.

The LINC00152/miR-138 Axis Facilitates Gastric Cancer Progression by Mediating SIRT2

Gastric cancer (GC) is the most common gastrointestinal cancer and the main cause of tumor-related death. Exploring markers for early diagnosis and new therapeutic targets is always on the way. In the last 10 years, long noncoding RNAs (lncRNAs) have been widely proved to be involved in the progress of many tumors and are regarded as potential targets for tumor therapy. We found that LINC00152, a newly identified lncRNA, was significantly upregulated in GC tissues and affected clinicopathological characteristics in GC patients. Furthermore, we observed that LINC00152 knockdown can significantly reduce cell proliferation and promote apoptosis in human gastric cancer cells. Further bioinformatic analysis indicated that LINC00152 competitively bound with miR-138 and regulated the expression of miR-138. Moreover, SIRT2 was further proved to be a downstream target of miR-138. Overall, this study elucidates the molecular mechanism of LINC00152 underlying the malignant phenotype of GC cells by mediating miR-138/SIRT2 axis, which provides a new understanding of the role and molecular mechanism of lncRNA in GC and also provides a new way for the treatment of gastric cancer.

UNC5B-AS1 promotes the proliferation, migration and EMT of hepatocellular carcinoma cells via regulating miR-4306/KDM2A axis

Being one of the most prevalent malignancies, hepatocellular carcinoma (HCC) threatens the health of population all over the world. Numerous researches have confirmed that long noncoding RNAs (lncRNAs) play an important role in tumor progression. Nonetheless, the mechanisms of unc-5 netrin receptor B antisense RNA 1 (UNC5B-AS1) in HCC remain obscure. Thus, this study aims to investigate the regulatory role and mechanism of UNC5B-AS1 in HCC cells. In our research, UNC5B-AS1 was subjected to gene expression analysis by RT-qPCR. Biological functions of UNC5B-AS1 in HCC cells were measured by MTT, colony formation, EdU and transwell assays. The combination between UNC5B-AS1, lysine demethylase 2A (KDM2A) and miR-4306 was validated by mechanism assays. Result showed UNC5B-AS1 was upregulated in HCC tissues and cells, contributing to the development of cancer staging and survival rate of HCC patients. Moreover, UNC5B-AS1 deficiency inhibited the proliferation, migration and epithelial-mesenchymal transition (EMT) of HCC cells. Furthermore, UNC5B-AS1 could interact with miR-4306 in HCC cells. Similarly, KDM2A was proved as the target gene of miR-4306. Finally, miR-4306 downregulation or KDM2A overexpression reversed the prohibitive role of UNC5B-AS1 knockdown in HCC progression. In short, UNC5B-AS1 accelerates the proliferation, migration and EMT of HCC cells via the regulation of miR-4306/KDM2A axis.

IL13 Acts Directly on Gastric Epithelial Cells to Promote Metaplasia Development During Chronic Gastritis

BACKGROUND & AIMS

It is well established that chronic inflammation promotes gastric cancer-associated metaplasia, but little is known regarding the mechanisms by which immune cells and cytokines regulate metaplastic cellular changes. The goals of this study were to identify interleukin 13 (IL13)-producing immune cells, determine the gastric epithelial cell response(s) to IL13, and establish the role(s) of IL13 in metaplasia development.

METHODS

Experiments used an established mouse model of autoimmune gastritis (TxA23), TxA23×Il4ra-/- mice, which develop gastritis but do not express the IL4/IL13-receptor subunit IL4Rα, and TxA23×Il13-Yfp mice, which express yellow fluorescent protein in IL13-producing cells. Flow cytometry was used to measure IL13 secretion and identify IL13-producing immune cells. Mouse and human gastric organoids were cultured with IL13 to determine epithelial cell response(s) to IL13. Single-cell RNA sequencing was performed on gastric epithelial cells from healthy and inflamed mouse stomachs. Mice with gastritis were administered IL13-neutralizing antibodies and stomachs were analyzed by histopathology and immunofluorescence.

RESULTS

We identified 6 unique subsets of IL13-producing immune cells in the inflamed stomach. Organoid cultures showed that IL13 acts directly on gastric epithelium to induce a metaplastic phenotype. IL4Rα-deficient mice did not progress to metaplasia. Single-cell RNA sequencing determined that gastric epithelial cells from IL4Rα-deficient mice up-regulated inflammatory genes but failed to up-regulate metaplasia-associated transcripts. Neutralization of IL13 significantly reduced and reversed metaplasia development in mice with gastritis.

CONCLUSIONS

IL13 is made by a variety of immune cell subsets during chronic gastritis and promotes gastric cancer-associated metaplastic epithelial cell changes. Neutralization of IL13 reduces metaplasia severity during chronic gastritis.

Emerging Roles of LncRNAs in the EZH2-regulated Oncogenic Network

Cancer is a life-threatening disease, but cancer therapies based on epigenetic mechanisms have made great progress. Enhancer of zeste homolog 2 (EZH2) is the key catalytic component of Polycomb repressive complex 2 (PRC2) that mediates the tri-methylation of lysine 27 on histone 3 (H3K27me3), a well-recognized marker of transcriptional repression. Mounting evidence indicates that EZH2 is elevated in various cancers and associates with poor prognosis. In addition, many studies revealed that EZH2 is also involved in transcriptional repression dependent or independent of PRC2. Meanwhile, long non-coding RNAs (lncRNAs) have been reported to regulate numerous and diverse signaling pathways in oncogenesis. In this review, we firstly discuss functional interactions between EZH2 and lncRNAs that determine PRC2-dependent and -independent roles of EZH2. Secondly, we summarize the lncRNAs regulating EZH2 expression at transcription, post-transcription and post-translation levels. Thirdly, we review several oncogenic pathways cooperatively regulated by lncRNAs and EZH2, including the Wnt/β-catenin and p53 pathways. In conclusion, lncRNAs play a key role in the EZH2-regulated oncogenic network with many fertile directions to be explored.

LncRNA SNHG7 Regulates Gastric Cancer Progression by miR-485-5p

Background

Long noncoding ribonucleic acids (lncRNAs) were closely related to the development of gastric cancer. This study investigated the effect of SNHG7 on gastric cancer progression and its potential molecular mechanism.

Methods

SNHG7 and microRNA-485-5p (miR-485-5p) expressions in gastric cancer tissues and cells were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell counting kit-8 (CCK-8), wound healing, and transwell experiments were used to detect cell proliferation, migration, and invasion. The dual luciferase reporter assay, RNA immunoprecipitation (RIP) experiment, and Pearson's correlation analysis were used to confirm the relationship between SNHG7 and miR-485-5p.

Results

SNHG7 expression was increased in human gastric cancer tissues and cells. Knockdown of SNHG7 could notably inhibit the gastric cancer cells proliferation, migration, and invasion. The dual-luciferase reporter assay and RIP experiments proved that miR-485-5p was a direct target of SNHG7. At the same time, further experiments demonstrated that miR-485-5p inhibition reversed the suppression of SNHG7 knockdown on gastric cancer cells proliferation, migration, and invasion.

Conclusions

SNHG7 knockdown could hamper gastric cancer progression via inhibiting miR-485-5p expression, providing a novel understanding for gastric cancer development.

The role of miR-101 in esophageal and gastric cancer

miR-101 is downregulated in various types of cancer, leading to the notion that miR-101 acts as a suppressor in cancer cell progression. The comprehensive mechanisms underlying the effects of miR-101 and the exact role of miR-101 dysregulations in esophagogastric tumors have not been fully elucidated. This review aims to summarize all current knowledge on the association between miR-101 expression and esophagogastric malignancies and to clarify the pathogenetic pathways and the possible prognostic and therapeutic role of miR-101 in those cancer types. miR-101 seems to play crucial role in esophageal and gastric cancer biology and tumorigenesis. It could also be a promising novel diagnostic and therapeutic target, as well as it may serve as a significant predictive biomarker in esophagogastric cancer.

X-factors in human disease: Impact of gene content and dosage regulation

The gene content of the X and Y chromosomes has dramatically diverged during evolution. The ensuing dosage imbalance within the genome of males and females has led to unique chromosome-wide regulatory mechanisms with significant and sex-specific impacts on X-linked gene expression. X inactivation or silencing of most genes on one X chromosome chosen at random in females profoundly affects the manifestation of X-linked diseases, as males inherit a single maternal allele, while females express maternal and paternal alleles in a mosaic manner. An additional complication is the existence of genes that escape X inactivation and thus are ubiquitously expressed from both alleles in females. The mosaic nature of X-linked gene expression and the potential for escape can vary between individuals, tissues, cell types, and stages of life. Our understanding of the specialized nature of X-linked genes and of the multilayer epigenetic regulation that influence their expression throughout the organism has been helped by molecular studies conducted by tissue-specific and single-cell-specific approaches. In turn, the definition of molecular events that control X silencing has helped develop new approaches for the treatment of some X-linked disorders. This review focuses on the peculiarities of the X chromosome genetic content and epigenetic regulation in shaping the manifestation of congenital and acquired X-linked disorders in a sex-specific manner.

LncRNA XIST Contributes to Cisplatin Resistance of Lung Cancer Cells by Promoting Cellular Glycolysis through Sponging miR-101-3p

BACKGROUND

Non-small-cell lung carcinoma is one of the most frequently diagnosed cancers. Cisplatin (CDDP) is a currently applied standard anticancer agent for advanced lung cancers. Although effectively clinical response was achieved initially, a large fraction of lung cancer patients developed cisplatin resistance. Therefore, understanding the molecular mechanisms of chemoresistance is crucial for anti-lung cancer therapy. Long non-coding RNA (lncRNA)-X-inactive-specific transcript (XIST) has been reported to be positively associated with multiple cancers. Currently, the precise role and mechanism of XIST in cisplatin resistance of lung cancer have not been elucidated.

METHODS

The expression levels of miR-101-3p and lncRNA XIST were detected by qRT-PCR. Cisplatin-resistant lung cancer cell line was established by selecting the survival cells under gradually increased cisplatin treatments. The cell proliferation was detected by MTT assay, and the cellular glucose metabolism rate was evaluated by Seahorse metabolic flux analysis and glucose uptake and lactate product assays. Glycolysis-related protein expression levels were detected by Western blot. Dual luciferase reporter was constructed to determine the lncRNA-miRNA interaction.

RESULTS

Here, we report XIST is significantly upregulated in lung cancer tissues compared with normal lung tissues. In addition, cisplatin-resistant lung cancer cells displayed remarkably elevated XIST expression. We demonstrated that miR-101-3p functioned as a tumor suppressor in lung cancer and sensitized lung cancer cells to cisplatin. Bioinformatics analysis predicted miR-101-3p could be a potential target of XIST through direct binding with it as a competing endogenous RNA, which was further validated from lung tumor tissues and cell lines by luciferase assay. Intriguingly, XIST significantly promoted cellular glycolysis rate of lung cancer cells. The extracellular acidification rate, glucose uptake, and lactate product were elevated by XIST overexpression. On the contrary, miR-101-3p effectively suppressed glycolysis rate. Finally, we demonstrated silencing XIST significantly recovered miR-101-3p expression and downregulated expression of glycolysis key enzymes, a phenotype could be further overridden by miR-101-3p inhibition.

CONCLUSIONS

This study reveals a new molecular mechanism for the lncRNA-XIST-promoted cisplatin resistance via sponging miR-101-3p, leading to de-repression of cellular glycolysis. Moreover, these findings warrant further in vivo investigations to study XIST as a potential target to overcome cisplatin resistance.

MiR-101 Attenuates Myocardial Infarction-induced Injury by Targeting DDIT4 to Regulate Autophagy

BACKGROUND

Myocardial Infarction (MI), a kind of heart deficiency, is the main cause of death and disability. Autophagy, a metabolic process for the degradation of damaged proteins or organelles, is important for cardiac functions and regulated by several miRNAs including miRNA- 101. The aim of this research was to investigate the effects of miR-101 in myocardial infarctioninduced injury and the related mechanisms.

METHODS

MI model was induced by ligation of the left coronary artery. The in vitro model was established by hypoxia-induced H9c2 cells (rat myocardial cells). The overexpression of miR-101 was achieved by transfection. The expression of associated proteins was analyzed by Western blotting. The level of miR-101 was analyzed by reverse transcription-polymerase chain reaction (RTPCR). The target genes for miR-101 and the target sites were analyzed by TargetScan.

RESULTS

The results showed that miR-101 was decreased in MI mice (P<0.01). Autophagy and apoptosis were increased in MI-induced injury (in vivo) and in hypoxia treated myocardial cells (in vitro) (P<0.01). miR-101 overexpression inhibited the increase of autophagy and apoptosis in mice and myocardial cells (P<0.01). DDIT4 was a target gene of miR-101 and expressed increasingly in MI-induced injury mice and hypoxia treated myocardial cells. miR-101 could negatively regulate the expression of DDIT4.

CONCLUSION

This research suggested that miR-101 attenuated- MI-induced injury by targeting DDIT4 to regulate autophagy, which indicated that miR-101 or DDIT4 may be potential therapeutic targets for heart injury.

Dysregulation of lncRNA in Helicobacter pylori-Infected Gastric Cancer Cells

Helicobacter pylori (H. pylori) infection is the most common cause of gastric cancer (GC). This microorganism is genetically diverse; GC is caused by several genetic deregulations in addition to environmental factors and bacterial virulence factors. lncRNAs (long noncoding RNAs) are significant biological macromolecules in GC, have specific functions in diseases, and could be therapeutic targets. Altered lncRNAs can lead to the abnormal expression of adjacent protein-coding genes, which may be important in cancer development. Their mechanisms have not been well understood, so we are going to investigate the risk of GC in a population with both high lncRNA and H. pylori infection.

Roles of ncRNAs as ceRNAs in Gastric Cancer

Although ignored in the past, with the recent deepening of research, significant progress has been made in the field of non-coding RNAs (ncRNAs). Accumulating evidence has revealed that microRNA (miRNA) response elements regulate RNA. Long ncRNAs, circular RNAs, pseudogenes, miRNAs, and messenger RNAs (mRNAs) form a competitive endogenous RNA (ceRNA) network that plays an essential role in cancer and cardiovascular, neurodegenerative, and autoimmune diseases. Gastric cancer (GC) is one of the most common cancers, with a high degree of malignancy. Considerable progress has been made in understanding the molecular mechanism and treatment of GC, but GC’s mortality rate is still high. Studies have shown a complex ceRNA crosstalk mechanism in GC. lncRNAs, circRNAs, and pseudogenes can interact with miRNAs to affect mRNA transcription. The study of the involvement of ceRNA in GC could improve our understanding of GC and lead to the identification of potential effective therapeutic targets. The research strategy for ceRNA is mainly to screen the different miRNAs, lncRNAs, circRNAs, pseudogenes, and mRNAs in each sample through microarray or sequencing technology, predict the ceRNA regulatory network, and, finally, conduct functional research on ceRNA. In this review, we briefly discuss the proposal and development of the ceRNA hypothesis and the biological function and principle of ceRNAs in GC, and briefly introduce the role of ncRNAs in the GC’s ceRNA network.

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.

Role of Long Noncoding RNAs ZlMSTRG.11348 and UeMSTRG.02678 in Temperature-Dependent Culm Swelling in Zizania latifolia

Temperature influences the physiological processes and ecology of both hosts and endophytes; however, it remains unclear how long noncoding RNAs (lncRNAs) modulate the consequences of temperature-dependent changes in host-pathogen interactions. To explore the role of lncRNAs in culm gall formation induced by the smut fungus Ustilago esculenta in Zizania latifolia, we employed RNA sequencing to identify lncRNAs and their potential cis-targets in Z. latifolia and U. esculenta under different temperatures. In Z. latifolia and U. esculenta, we identified 3194 and 173 lncRNAs as well as 126 and four potential target genes for differentially expressed lncRNAs, respectively. Further function and expression analysis revealed that lncRNA ZlMSTRG.11348 regulates amino acid metabolism in Z. latifolia and lncRNA UeMSTRG.02678 regulates amino acid transport in U. esculenta. The plant defence response was also found to be regulated by lncRNAs and suppressed in Z. latifolia infected with U. esculenta grown at 25 °C, which may result from the expression of effector genes in U. esculenta. Moreover, in Z. latifolia infected with U. esculenta, the expression of genes related to phytohormones was altered under different temperatures. Our results demonstrate that lncRNAs are important components of the regulatory networks in plant-microbe-environment interactions, and may play a part in regulating culm swelling in Z. latifolia plants.

High miR-3650 expression in nasopharyngeal carcinoma and its clinical prognostic values

BACKGROUND

A recent study has reported that miR-3650 expression was significant reduced in hepatocellular carcinoma and predicted poor prognosis. However, the role of miR-3650 in nasopharyngeal carcinoma (NPC) remains indefinite.

METHODS

Total 140 cases of NPCs were included in this study. The expression of miR-3650 was determined in NPC tissues and adjacent nontumor tissues using qRT-PCR. Then the relationship between miR-3650 expression and clinicopathological features as well as survival were analyzed.

RESULTS

The expression of miR-3650 was significant higher in NPC tissues than that in adjacent nontumor tissues (P <  0.001). High expression of miR-3650 was significant correlated with tumor progression and distant metastasis of NPC patients. And patients with high miR-3650 expression have much worse 5-year overall survival (OS) and 5-year progression-free survival (PFS) than those with low expression (all P <  0.0001). Furthermore, Cox regression analysis showed that miR-3650 was an independent risk predictor for OS and PFS in NPC patients (all P =  0.000).

CONCLUSION

Our results demonstrated for the first time that miR-3650 was markedly upregulated in NPC tissues and positively associated with tumor progression and poor survival, suggesting that miR-3650 may be a potential novel prognostic biomarker and therapeutic target for NPC patients.

Long non-coding RNA Xist regulates oocyte loss via suppressing miR-23b-3p/miR-29a-3p maturation and upregulating STX17 in perinatal mouse ovaries

The fecundity of female mammals is resolved by the limited size of the primordial follicle (PF) pool formed perinatally. The establishment of PF pool is accompanied by a significant programmed oocyte death. Long non-coding RNAs (lncRNA) are central modulators in regulating cell apoptosis or autophagy in multiple diseases, however, the significance of lncRNAs governing perinatal oocyte loss remains unknown. Here we find that Yin-Yang 1 (YY1) directly binds to the lncRNA X-inactive-specific transcript (Xist) promoter and facilitates Xist expression in the perinatal mouse ovaries. Xist is highly expressed in fetal ovaries and sharply downregulated along with the establishment of PF pool after birth. Gain or loss of function analysis reveals that Xist accelerates oocyte autophagy, mainly through binding to pre-miR-23b or pre-miR-29a in the nucleus and preventing the export of pre-miR-23b/pre-miR-29a to the cytoplasm, thus resulting in decreased mature of miR-23b-3p/miR-29a-3p expression and upregulation miR-23b-3p/miR-29a-3p co-target, STX17, which is essential for timely control of the degree of oocyte death in prenatal mouse ovaries. Overall, these findings identify Xist as a key non-protein factor that can control the biogenesis of miR-23b-3p/miR-29a-3p, and this YY1-Xist-miR-23b-3p/miR-29a-3p-STX17 regulatory axis is responsible for perinatal oocyte loss through autophagy.

SPRY4 suppresses proliferation and induces apoptosis of colorectal cancer cells by repressing oncogene EZH2

Colorectal cancer (CRC), a common malignant tumor in the digestive tract, is a leading cause of cancer-related death. SPRY4 has been reported to act as a tumor suppressor gene in various tumors. This study aims to assess the role of SPRY4 in colorectal cancer (CRC) and uncover its underlying mechanisms. Firstly, the expression levels of SPRY4 were measured in CRC cell lines. SPRY4-overexpressing or silencing plasmids were transfected into CRC cells to regulate its expression level. CCK-8, colony formation, EdU assay, wound-healing and Transwell assays were performed to determine cell proliferation, invasion and migration abilities. Then, apoptosis was measured by flow cytometry analysis, and the expression of apoptosis-related protein was analyzed by western-blotting. Next, the in vivo tumorigenesis assay was performed in nude mice. According to the results, there was a lower expression of SPRY4 in CRC cell lines compared with normal cell line, and the overexpression of SPRY4 significantly suppressed cell proliferation, migration and invasion, and promoted apoptosis in SW480 cells. Moreover, the enhanced proliferation, invasion and migration upon SPRY4 silencing was reversed by EZH2 inhibition. In addition, we found that the overexpression of SPRY4 inhibited tumorigenesis in vivo by diminishing the size and weight of the tumors. Our study indicates that SPRY4 might be a potential tumor suppressor gene and prognostic factor for patients with CRC.

Silencing of long non-coding RNA XIST represses gastric cancer progression through blocking NFκB pathway via inhibiting HNF4A-mediated transcription of EPHA1

Gastric cancer (GC) is a common cancer and a leading cause of cancer-related deaths worldwide. Recent studies have supported the important role of long non-coding RNAs (lncRNAs) in GC progression. This study identified functional significance of X inactive specific transcript (XIST) in GC. The expression of XIST and EPHA1 in GC tissues and cells was measured. Then, dual luciferase reporter gene assay, RNA immunoprecipitation (RIP) assay and Chromatin Immunoprecipitation (ChIP) assay were performed to explore the interaction among XIST, EPHA1 and HNF4A. The effects of XIST on GG progression were evaluated by determining expression of proliferation- and invasion-related proteins (Ki67, PCNA, MMP-2, and MMP-9). Further, the functional role of XIST in GC with the involvement of NFκB pathway was also analyzed. Subsequently, the tumor growth in nude mice was evaluated. High expression of XIST and EPHA1 was observed in GC. XIST elevated EPHA1 expression by recruiting HNF4A. In addition, silencing of XIST inhibited GC progression in vitro and in vivo. Overexpressed XIST and EPHA1 yielded a reversed effect on cell proliferation and invasion. SN50 treatment (inhibitor of NFκB pathway) counteracted the promotive effect on GC cell proliferation and invasion mediated by XIST. The present study unveils that XIST increases the enrichment of HNF4A in the promoter region of EPHA1, thus promoting the deterioration of GC.

BBOX1-AS1 Accelerates Gastric Cancer Proliferation by Sponging miR-3940-3p to Upregulate BIRC5 Expression

BACKGROUND

Gastric cancer (GC) is one type of the most general malignancies in the globe. Research increasingly suggests long non-coding RNAs (lncRNAs) exert crucial roles in GC. However, the function of BBOX1-AS1 in GC has not been reported yet, it needs more explorations.

AIMS

The aim of the study is to figure out the role and related regulation mechanism of BBOX1-AS1 in GC.

METHODS

RT-qPCR assay was applied to detect genes expression. The role of BBOX1-AS1 in GC was investigated by cell counting kit-8, colony formation, tunel detection, and western blot assays. The binding ability between miR-3940-3p and BBOX1-AS1 (or BIRC5) by RIP, RNA pull-down and luciferase reporter assays.

RESULTS

The expression of BBOX1-AS1 presented significantly upregulation in GC tissues and cells. Moreover, upregulation of BBOX1-AS1 promoted GC cell proliferation, and inhibited GC cell apoptosis. However, downregulation of BBOX1-AS1 led to opposite results. Furtherly, we discovered that BBOX1-AS1 bound with miR-3940-3p and also negatively regulated miR-3940-3p. Besides, it proved that miR-3940-3p interplayed with BIRC5 and negatively regulated BIRC5. Through rescue experiments, we proved that BIRC5 reversed miR-3940-3p-mediated cell proliferation or apoptosis in BBOX1-AS1-dysregulated GC cells.

CONCLUSIONS

BBOX1-AS1 accelerates GC proliferation by sponging miR-3940-3p to upregulate BIRC5 expression, which may guide a new direction into the therapeutic strategies of GC.