LncRNA MEG3 acts a biomarker and regulates cell functions by targeting ADAR1 in colorectal cancer

Unraveling the ncRNA landscape that governs colorectal cancer: A roadmap to personalized therapeutics

Colorectal cancer (CRC) being one of the most common malignancies, has a significant death rate, especially when detected at an advanced stage. In most cases, the fundamental aetiology of CRC remains unclear despite the identification of several environmental and intrinsic risk factors. Numerous investigations, particularly in the last ten years, have indicated the involvement of epigenetic variables in this type of cancer. The development, progression, and metastasis of CRC are influenced by long non-coding RNAs (lncRNAs), which are significant players in the epigenetic pathways. LncRNAs are implicated in diverse pathological processes in CRC, such as liver metastasis, epithelial to mesenchymal transition (EMT), inflammation, and chemo-/radioresistance. It has recently been determined that CRC cells and tissues exhibit dysregulation of tens of oncogenic and tumor suppressor lncRNAs. Serum samples from CRC patients exhibit dysregulated expressions of several of these transcripts, offering a non-invasive method of detecting this kind of cancer. In this review, we outlined the typical paradigms of the deregulated lncRNA which exert significant role in the underlying molecular mechanisms of CRC initiation and progression. We comprehensively discuss the role of lncRNAs as innovative targets for CRC prognosis and treatment.

A possible role of lncRNA MEG3 and lncRNA MAFG-AS1 on miRNA 147-b in the pathogenesis of Behcet's disease

Behcet's disease (BD) is a multisystem disease with altered Toll-like receptors (TLRs) on macrophages. Long noncoding RNA Maternally expressed gene 3 (lncRNA MEG3) and lncRNA Musculoaponeurotic fibrosarcoma oncogene family, protein G antisense 1 (MAFG-AS1) are regulators of microRNA (miRNA) 147-b, which is induced upon TLR stimulation. We included fifty BD patients, and fifty age and sex-matched controls. Real-time polymerase chain reaction (PCR) was used to measure the expression levels of serum lncRNA MEG3, lncRNA MAFG-AS1, and miRNA 147-b. LncRNA MEG3 and lncRNA MAFG-AS1 were significantly downregulated while miRNA 147-b was significantly upregulated in the BD patients' serum compared to the controls with p-value <0.001. Receiver operation characteristics (ROC) curve analysis revealed that the three biomarkers can discriminate between BD and control subjects with 76%, 100%, and 70% sensitivity respectively, and 100% specificity for all of them. There was a lower expression level of lnc RNA MEG3 among patients who had new eye involvement in the last month in comparison to those without new eye involvement (p-value=0.017). So, LncRNA MEG3, lncRNA MAFG-AS1, and miRNA147-b are promising diagnostic markers and therapeutic targets for BD patients. LncRNA MEG3 can be used as a predictor for new BD ocular involvement.

Analysis of long non-coding RNA RMRP in the diagnosis and prognosis of coronary artery disease

BACKGROUND

Long non-coding RNAs (lncRNAs) are abundant and closely related to the occurrence and development of human diseases. LncRNAs are known to play a key role in many cardiovascular diseases. The purpose of this study was to investigate the effect of the RNA component of mitochondrial RNA-processing endoribonuclease (RMRP) on the degree of coronary artery lesions and prognosis in patients with coronary artery disease (CAD).

METHODS

Patients who underwent coronary angiography (CAG) and dynamical-single photon emission computed tomography (D-SPECT) were selected as study subjects, and the results of CAG were reviewed, and the patients were grouped according to SYNTAX score. Evaluate the factors affecting SYNTAX scores. The follow-up analysis was conducted, and the endpoint events were major adverse cardiovascular events (MACEs). Kaplan-Meier method was used to estimate the survival rate, and multivariate Cox regression was used to analyze the relationship between RMRP and MACEs.

RESULTS

The expression level of serum RMRP in patients with CAD was significantly higher than that in healthy people. Multivariate Logistic regression analysis showed that age, low-density lipoprotein cholesterol (LDL-C), RMRP and rest left ventricular ejection fraction (LVEF) were independent factors that affected SYNTAX scores. There were 19 cases of MACEs in the high RMRP group and 9 cases in the low RMRP group, and there was a significant difference in the MACE free survival curve between the two groups. Multivariate Cox regression analysis showed that age, SYNTAX score, rest LVEF and RMRP were risk factors for MACEs.

CONCLUSIONS

Serum RMRP is a key factor affecting the degree of coronary artery disease and prognosis in CAD patients.

Association of lncRNA MEG3 rs941576 polymorphism, expression profile, and its related targets with the risk of obesity-related colorectal cancer: potential clinical insights

The identification of novel screening tools is imperative to empower the early detection of colorectal cancer (CRC). The influence of the long non-coding RNA maternally expressed gene 3 (MEG3) rs941576 single nucleotide polymorphism on CRC susceptibility remains uninvestigated. This research appraised MEG3 rs941576 association with the risk and clinical features of CRC and obesity-related CRC and its impact on serum MEG3 expression and its targets miR-27a/insulin-like growth factor 1 (IGF1)/IGF binding protein 3 (IGFBP3) and miR-181a/sirtuin 1 (SIRT1), along with the potential of these markers in obesity-related CRC diagnosis. 130 CRC patients (60 non-obese and 70 obese) and 120 cancer-free controls (64 non-obese and 56 obese) were enrolled. MEG3 targets were selected using bioinformatics analysis. MEG3 rs941576 was associated with magnified CRC risk in overall (OR (95% CI) 4.69(1.51-14.57), P = 0.0018) and stratified age and gender groups, but not with obesity-related CRC risk or MEG3/downstream targets' expression. Escalated miR-27a and IGFBP3 and reduced IGF1 serum levels were concomitant with MEG3 downregulation in overall CRC patients versus controls and obese versus non-obese CRC patients. Serum miR-181a and SIRT1 were upregulated in CRC patients versus controls but weren't altered in the obese versus non-obese comparison. Serum miR-181a and miR-27a were superior in overall and obesity-related CRC diagnosis, respectively; meanwhile, IGF1 was superior in distinguishing obese from non-obese CRC patients. Only serum miR-27a was associated with obesity-related CRC risk in multivariate logistic analysis. Among overall CRC patients, MEG3 rs941576 was associated with lymph node (LN) metastasis and tumor stage, serum MEG3 was negatively correlated with tumor stage, while SIRT1 was correlated with the anatomical site. Significant correlations were recorded between MEG3 and anatomical site, SIRT1 and tumor stage, and miR-27a/IGFBP3 and LN metastasis among obese CRC patients, while IGF1 was correlated with tumor stage and LN metastasis among non-obese CRC patients. Conclusively, this study advocates MEG3 rs941576 as a novel genetic marker of CRC susceptibility and prognosis. Our findings accentuate circulating MEG3/miR-27a/IGF1/IGFBP3, especially miR-27a as valuable markers for the early detection of obesity-related CRC. This axis along with SIRT1 could benefit obesity-related CRC prognosis.

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.

LncRNA MEG3 inhibits the proliferation and migration abilities of colorectal cancer cells by competitively suppressing MiR-31 and reducing the binding of MiR-31 to target gene SFRP1

To explore the potential mechanism of long-chain non-coding ribonucleic acid (lncRNA) maternal expression gene 3 (MEG3) in colorectal cancer (CRC). The relationship between MEG3 and miR-31 was detected by dual-luciferase assay. Quantitative polymerase chain reaction was utilized to determine the expression of MEG3 in CRC cell lines. Cell Counting Kit-8 assay was performed to detect cell proliferation. Transwell, cell scratch wound assay, and monoclonal proliferation assay were used to detect the proliferation, migration, and invasion of cells. In addition, cell motility was evaluated by detecting the expression of cellular pseudopodia protein α-actinin via immunofluorescence assay, and cell proliferation and motility were judged by determining the expressions of Ki-67, MMP2 and MMP9 via Western blotting. The effect of MEG3 and miR-31 on the development of colorectal cancer was verified by nude mouse tumor-bearing assay and HE staining. Transient transfection with MEG3 overexpression plasmid revealed that MEG3 inhibited the proliferation and motility of cells. The results of dual-luciferase assay showed that MEG3 could specifically inhibit the expression of miR-31, which inhibits the development of colorectal cancer. Transwell, cell scratch wound assay, and monoclonal proliferation experiment showed that miR-31 enhanced cell proliferation, migration and invasion. MEG3 overexpression plasmid was capable of reversing the proliferation and motility of CRC cells enhanced by miR-31. MEG3 can inhibit the proliferation and motility of CRC cells by competitively suppressing the binding of miR-31 to the target gene SFRP1, thus playing an inhibitory role in the pathogenesis of CRC.

Prognostic value of circulating long non-coding RNAs in colorectal cancer patients: a meta-analysis

OBJECTIVES

This meta-analysis aimed to evaluate the prognostic significance of circulating long non-coding RNAs (lncRNAs) in colorectal cancer (CRC).

METHODS

A comprehensive literature search was conducted in databases (Embase, Web of Science, PubMed, and Cochrane Library) up to July 2022. The quality of included studies was assessed using the Newcastle-Ottawa Scale (NOS). Statistical analysis was performed with Review Manager 5.4 and Stata 17.0. Publication bias was assessed using Begg's test, and sensitivity analysis was conducted to validate the meta-analysis results.

RESULTS

Ten articles, comprising 1,473 CRC patients and 18 different circulating lncRNAs, were included. Thirteen circulating lncRNAs were found to be up-regulated in CRC patients, while five were down-regulated. High expression of circulating lncRNAs up-regulated in CRC patients was associated with shorter CRC OS (HR = 2.91, 95% CI: 1.17, 7.22; P = 0.02, I2 = 86%). Conversely, high expression of circulating lncRNAs down-regulated in CRC patients was linked to longer CRC OS (HR = 0.16, 95% CI: 0.07, 0.40; P < 0.0001, I2 = 0%) and improved DFS (HR = 0.52, 95% CI: 0.37, 0.74; P = 0.0002, I2 = 0%). Additionally, circulating lncRNA levels correlated with TNM staging, tumor location, and lymph node metastasis.

CONCLUSION

Circulating lncRNAs show promise as prognostic markers for CRC patients, but further studies are warranted to validate these findings.

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.

The Role of Non-Coding RNAs in Myelodysplastic Neoplasms

Myelodysplastic syndromes or neoplasms (MDS) are a heterogeneous group of myeloid clonal disorders characterized by peripheral blood cytopenias, blood and marrow cell dysplasia, and increased risk of evolution to acute myeloid leukemia (AML). Non-coding RNAs, especially microRNAs and long non-coding RNAs, serve as regulators of normal and malignant hematopoiesis and have been implicated in carcinogenesis. This review presents a comprehensive summary of the biology and role of non-coding RNAs, including the less studied circRNA, siRNA, piRNA, and snoRNA as potential prognostic and/or predictive biomarkers or therapeutic targets in MDS.

Data-driven decision-making for precision diagnosis of digestive diseases

Modern omics technologies can generate massive amounts of biomedical data, providing unprecedented opportunities for individualized precision medicine. However, traditional statistical methods cannot effectively process and utilize such big data. To meet this new challenge, machine learning algorithms have been developed and applied rapidly in recent years, which are capable of reducing dimensionality, extracting features, organizing data and forming automatable data-driven clinical decision systems. Data-driven clinical decision-making have promising applications in precision medicine and has been studied in digestive diseases, including early diagnosis and screening, molecular typing, staging and stratification of digestive malignancies, as well as precise diagnosis of Crohn's disease, auxiliary diagnosis of imaging and endoscopy, differential diagnosis of cystic lesions, etiology discrimination of acute abdominal pain, stratification of upper gastrointestinal bleeding (UGIB), and real-time diagnosis of esophageal motility function, showing good application prospects. Herein, we reviewed the recent progress of data-driven clinical decision making in precision diagnosis of digestive diseases and discussed the limitations of data-driven decision making after a brief introduction of methods for data-driven decision making.

Genomic and Transcriptomic Research in the Discovery and Application of Colorectal Cancer Circulating Markers

Colorectal cancer (CRC) is the most frequently occurring malignancy in the world. However, the mortality from CRC can be reduced through early diagnostics, selection of the most effective treatment, observation of the therapy success, and the earliest possible diagnosis of recurrences. A comprehensive analysis of genetic and epigenetic factors contributing to the CRC development is needed to refine diagnostic, therapeutic, and preventive strategies and to ensure appropriate decision making in managing specific CRC cases. The liquid biopsy approach utilizing circulating markers has demonstrated its good performance as a tool to detect the changes in the molecular pathways associated with various cancers. In this review, we attempted to brief the main tendencies in the development of circulating DNA and RNA-based markers in CRC such as cancer-associated DNA mutations, DNA methylation changes, and non-coding RNA expression shifts. Attention is devoted to the existing circulating nucleic acid-based CRC markers, the possibility of their application in clinical practice today, and their future improvement. Approaches to the discovery and verification of new markers are described, and the existing problems and potential solutions for them are highlighted.

Interaction of lncRNAs with mTOR in colorectal cancer: a systematic review

Colorectal cancer (CRC) is the third most widespread cancer and the fourth leading lethal disease among different societies. It is thought that CRC accounts for about 10% of all newly diagnosed cancer cases with high-rate mortality. lncRNAs, belonging to non-coding RNAs, are involved in varied cell bioactivities. Emerging data have confirmed a significant alteration in lncRNA transcription under anaplastic conditions. This systematic review aimed to assess the possible influence of abnormal mTOR-associated lncRNAs in the tumorigenesis of colorectal tissue. In this study, the PRISMA guideline was utilized based on the systematic investigation of published articles from seven databases. Of the 200 entries, 24 articles met inclusion criteria and were used for subsequent analyses. Of note, 23 lncRNAs were prioritized in association with the mTOR signaling pathway with up-regulation (79.16%) and down-regulation (20.84%) trends. Based on the obtained data, mTOR can be stimulated or inhibited during CRC by the alteration of several lncRNAs. Determining the dynamic activity of mTOR and relevant signaling pathways via lncRNAs can help us progress novel molecular therapeutics and medications.

LncRNAs in colorectal cancer: Biomarkers to therapeutic targets

Colorectal cancer (CRC) is the third leading cause of cancer-related death in men and women worldwide. As early detection is associated with lower mortality, novel biomarkers are urgently needed for timely diagnosis and appropriate management of patients to achieve the best therapeutic response. Long noncoding RNAs (lncRNAs) have been reported to play essential roles in CRC progression. Accordingly, the regulatory roles of lncRNAs should be better understood in general and for identifying diagnostic, prognostic and predictive biomarkers in CRC specifically. In this review, the latest advances on the potential diagnostic and prognostic lncRNAs as biomarkers in CRC samples were highlighted, Current knowledge on dysregulated lncRNAs and their potential molecular mechanisms were summarized. The potential therapeutic implications and challenges for future and ongoing research in the field were also discussed. Finally, novel insights on the underlying mechanisms of lncRNAs were examined as to their potential role as biomarkers and therapeutic targets in CRC. This review may be used to design future studies and advanced investigations on lncRNAs as biomarkers for the diagnosis, prognosis and therapy in CRC.

Molecular regulation of hypoxia through the lenses of noncoding RNAs and epitranscriptome

Cells maintain homeostasis in response to environmental stress through specific cell stress responses. Hypoxic stress, well known to be associated with diverse solid tumors, is one of the main reasons for cancer-related mortality. Although cells can balance themselves well during hypoxic stress, the underlying molecular mechanisms are not well understood. The enhanced appreciation of diverse roles played by noncoding transcriptome and epigenome in recent years has brought to light the involvement of noncoding RNAs and epigenetic modifiers in hypoxic regulation. The emergence of techniques like deep sequencing has facilitated the identification of large numbers of long noncoding RNAs (lncRNAs) that are differentially regulated in various cancers. Similarly, proteomic studies have identified diverse epigenetic modifiers such as HATs, HDACs, DNMTs, polycomb groups of proteins, and their possible roles in the regulation of hypoxia. The crosstalk between lncRNAs and epigenetic modifiers play a pivotal role in hypoxia-induced cancer initiation and progression. Besides the lncRNAs, several other noncoding RNAs like circular RNAs, miRNAs, and so forth are also expressed during hypoxic conditions. Hypoxia has a profound effect on the expression of noncoding RNAs and epigenetic modifiers. Conversely, noncoding RNAs/epigenetic modifies can regulate the hypoxia signaling axis by modulating the stability of the hypoxia-inducible factors (HIFs). The focus of this review is to illustrate the molecular orchestration underlying hypoxia biology, especially in cancers, which can help in identifying promising therapeutic targets in hypoxia-induced cancers. This article is categorized under: RNA Turnover and Surveillance > Regulation of RNA Stability RNA in Disease and Development > RNA in Disease RNA Structure and Dynamics > RNA Structure, Dynamics and Chemistry.

The Biological Roles and Molecular Mechanisms of Long Non-Coding RNA MEG3 in the Hallmarks of Cancer

Long non-coding RNAs (lncRNAs) are critical regulators in various biological processes involved in the hallmarks of cancer. Maternally expressed gene 3 (MEG3) is lncRNA that regulates target genes through transcription, translation, post-translational modification, and epigenetic regulation. MEG3 has been known as a tumor suppressor, and its downregulation could be found in various cancers. Furthermore, clinical studies revealed that impaired MEG3 expression is associated with poor prognosis and drug resistance. MEG3 exerts its tumor suppressive effect by suppressing various cancer hallmarks and preventing cells from acquiring cancer-specific characteristics; as it could suppress tumor cells proliferation, invasion, metastasis, and angiogenesis; it also could promote tumor cell death and regulate tumor cell metabolic reprogramming. Hence, MEG3 is a potential prognostic marker, and overexpressing MEG3 might become a potential antitumor therapeutic strategy. Herein, we summarize recent knowledge regarding the role of MEG3 in regulating tumor hallmarks as well as the underlying molecular mechanisms. Furthermore, we also discuss the clinical importance of MEG3, as well as their potential in tumor prognosis and antitumor therapeutic strategies.

A review of current evidence about lncRNA MEG3: A tumor suppressor in multiple cancers

Long non-coding RNA (lncRNA) maternally expressed gene 3 (MEG3) is a lncRNA located at the DLK1-MEG3 site of human chromosome 14q32.3. The expression of MEG3 in various tumors is substantially lower than that in normal adjacent tissues, and deletion of MEG3 expression is involved in the occurrence of many tumors. The high expression of MEG3 could inhibit the occurrence and development of tumors through several mechanisms, which has become a research hotspot in recent years. As a member of tumor suppressor lncRNAs, MEG3 is expected to be a new target for tumor diagnosis and treatment. This review discusses the molecular mechanisms of MEG3 in different tumors and future challenges for the diagnosis and treatment of cancers through MEG3.

LncRNA MEG3: Potential stock for precision treatment of cardiovascular diseases

The prevalence and mortality rates of cardiovascular diseases are increasing, and new treatment strategies are urgently needed. From the perspective of basic pathogenesis, the occurrence and development of cardiovascular diseases are related to inflammation, apoptosis, fibrosis and autophagy of cardiomyocytes, endothelial cells and other related cells. The involvement of maternally expressed gene 3 (MEG3) in human disease processes has been increasingly reported. P53 and PI3K/Akt are important pathways by which MEG3 participates in regulating cell apoptosis. MEG3 directly or competitively binds with miRNA to participate in apoptosis, inflammation, oxidative stress, endoplasmic reticulum stress, EMT and other processes. LncRNA MEG3 is mainly involved in malignant tumors, metabolic diseases, immune system diseases, cardiovascular and cerebrovascular diseases, etc., LncRNA MEG3 has a variety of pathological effects in cardiomyocytes, fibroblasts and endothelial cells and has great clinical application potential in the prevention and treatment of AS, MIRI, hypertension and HF. This paper will review the research progress of MEG3 in the aspects of mechanism of action, other systemic diseases and cardiovascular diseases, and point out its great potential in the prevention and treatment of cardiovascular diseases. lncRNAs also play a role in endothelial cells. In addition, lncRNA MEG3 has shown biomarker value, prognostic value and therapeutic response measurement in tumor diseases. We boldly speculate that MEG3 will play a role in the emerging discipline of tumor heart disease.

Comprehensive landscape and future perspectives of long noncoding RNAs (lncRNAs) in colorectal cancer (CRC): Based on a bibliometric analysis

This review aimed to use bibliometric analysis to sort out, analyze and summarize the knowledge foundation and hot topics in the field of long noncoding RNAs (lncRNAs) in colorectal cancer (CRC), and point out future trends to inspire related research and innovation. We used CiteSpace to analyze publication outputs, countries, institutions, authors, journals, references, and keywords. Knowledge foundations, hotspots, and future trends were then depicted. The overall research showed the trend of biomedical-oriented multidisciplinary. Much evidence indicates that lncRNA plays the role of oncogene or tumor suppressor in the occurrence and development of CRC. Besides, many lncRNAs have multiple mechanisms. lncRNAs and metastasis of CRC, lncRNAs and drug resistance of CRC, and the clinical application of lncRNAs in CRC are current research hotspots. Through insight into the development trend of lncRNAs in CRC, this study will help researchers extract hidden valuable information for further research.

Epigenomic effects of vitamin D in colorectal cancer

Vitamin D regulates a plethora of physiological processes in the human body and has been proposed to exert several anticancer effects. Epigenetics plays an important role in regulating vitamin D actions. In this review, we highlight the recent advances in the understanding of different epigenetic factors such as lncRNAs, miRNAs, methylation and acetylation influenced by vitamin D and its downstream targets in colorectal cancer to find more potential therapeutic targets. We discuss how vitamin D exerts anticancer properties through interactions between the vitamin D receptor and genes (e.g., SLC30A10), the microenvironment, microbiota and other factors in colorectal cancer. Developing therapeutic approaches targeting the vitamin D signaling system will be aided by a better knowledge of the epigenetic impact of vitamin D.

Long non-coding RNAs involved in different steps of cancer metastasis

Non-proteincoding transcripts bearing 200 base pairs known as long non-coding RNAs (lncRNAs) play a role in a variety of molecular mechanisms, including cell differentiation, apoptosis and metastasis. Previous studies have suggested that frequently dysregulated lncRNAs play a crucial role in various aspects of cancer metastasis. Metastasis is the main leading cause of death in cancer. The role of lncRNAs in different stages of metastasis is the subject of this review. Based on in vitro and in vivo investigations on metastasis, we categorized lncRNAs into distinct stages of metastasis including angiogenesis, invasion, intravasation, survival in circulation, and extravasation. The involvement of lncRNAs in angiogenesis and invasion has been extensively studied. Here, we comprehensively discuss the role and functions of these lncRNAs with a particular focus on the molecular mechanisms.

Dynamic liquid biopsy components as predictive and prognostic biomarkers in colorectal cancer

Colorectal cancer (CRC) is one of the most common cancers worldwide. The diagnosis, prognosis and therapeutic monitoring of CRC depends largely on tissue biopsy. However, due to tumor heterogeneity and limitations such as invasiveness, high cost and limited applicability in longitudinal monitoring, liquid biopsy has gathered immense attention in CRC. Liquid biopsy has several advantages over tissue biopsy including ease of sampling, effective monitoring, and longitudinal assessment of treatment dynamics. Furthermore, the importance of liquid biopsy is signified by approval of several liquid biopsy assays by regulatory bodies indicating the powerful approach of liquid biopsy for comprehensive CRC screening, diagnostic and prognostics. Several liquid biopsy biomarkers such as novel components of the microbiome, non-coding RNAs, extracellular vesicles and circulating tumor DNA are extensively being researched for their role in CRC management. Majority of these components have shown promising results on their clinical application in CRC including early detection, observe tumor heterogeneity for treatment and response, prediction of metastases and relapse and detection of minimal residual disease. Therefore, in this review, we aim to provide updated information on various novel liquid biopsy markers such as a) oral microbiota related bacterial network b) gut microbiome-associated serum metabolites c) PIWI-interacting RNAs (piRNAs), microRNA(miRNAs), Long non-coding RNAs (lncRNAs), circular RNAs (circRNAs) and d) circulating tumor DNAs (ctDNA) and circulating tumor cells (CTC) for their role in disease diagnosis, prognosis, treatment monitoring and their applicability for personalized management of CRC.

Autophagy and gastrointestinal cancers: the behind the scenes role of long non-coding RNAs in initiation, progression, and treatment resistance

Gastrointestinal (GI) cancers comprise a heterogeneous group of complex disorders that affect different organs, including esophagus, stomach, gallbladder, liver, biliary tract, pancreas, small intestine, colon, rectum, and anus. Recently, an explosion in nucleic acid-based technologies has led to the discovery of long non-coding RNAs (lncRNAs) that have been found to possess unique regulatory functions. This class of RNAs is >200 nucleotides in length, and is characterized by their lack of protein coding. LncRNAs exert regulatory effects in GI cancer development by affecting different functions such as the proliferation and metastasis of cancer cells, apoptosis, glycolysis and angiogenesis. Over the past few decades, considerable evidence has revealed the important role of autophagy in both GI cancer progression and suppression. In addition, recent studies have confirmed a significant correlation between lncRNAs and the regulation of autophagy. In this review, we summarize how lncRNAs play a behind the scenes role in the pathogenesis of GI cancers through regulation of autophagy.

LINC00174 Facilitates Proliferation and Migration of Colorectal Cancer Cells via MiR-3127-5p/ E2F7 Axis

The literature indicates that LINC00174 promotes the growth of colorectal cancer (CRC) cells, but its research needs to be enriched. We tried to explore the function and mechanism of LINC00174 in CRC cell proliferation and migration. Bioinformatics analysis predicted the binding relationship and expressions of lncRNA, miRNA and mRNA. Clinical study analyzes the relationship between LINC00174 and clinical data characteristics of CRC patients. The expressions of LINC00174, miR-3127-5p and E2F7 were verified by RT-qPCR, and the combination of the two was verified by dual luciferase analysis and RNA immunoprecipitation as needed. Western blot was used to detect the expression of EMT-related protein and E2F7 protein. Functional experiments were used to evaluate the function of the target gene on CRC cells. LINC00174 was up-regulated in CRC clinical samples and cells and was related to the clinical characteristics of CRC patients. High-expression of LINC00174, contrary to the effect of siLINC00174, promoted cell viability, proliferation, migration and invasion, up-regulated the expressions of N-Cadherin, Vimentin, E2F7, and inhibited the expression of E-Cadherin. MiR-3127-5p was one of the targeted miRNAs of LINC00174 and was down-regulated in CRC samples. In addition, miR-3127-5p mimic partially reversed the malignant phenotype of CRC cells induced by LINC00174. Besides, E2F7 was a target gene of miR-3127-5p, and LINC00174 repressed miR-3127-5p to regulate E2F7. Our research reveals that LINC00174 affected the biological characteristics of CRC cells through regulated miR-3127-5p/ E2F7 axis.

Long non-coding RNAs: Emerging roles in periodontitis

Periodontitis is a major burden of public health, affecting 20%-50% of the global population. It is a complex inflammatory disease characterized by the destruction of supporting structures of the teeth, leading to tooth loss and the emergence or worsening of systematic diseases. Understanding the molecular mechanisms underlying the physiopathology of periodontitis is beneficial for targeted therapeutics. Long non-coding RNAs (lncRNAs), transcripts made up of more than 200 nucleotides, have emerged as novel regulators of many biological and pathological processes. Recently, an increasing number of dysregulated lncRNAs have been found to be implicated in periodontitis. In this review, an overview of lncRNAs, including their biogenesis, characteristics, function mechanisms and research approaches, is provided. And we summarize recent research reports on the emerging roles of lncRNAs in regulating proliferation, apoptosis, inflammatory responses, and osteogenesis of periodontal cells to elucidate lncRNAs related physiopathology of periodontitis. Furthermore, we have highlighted the underlying mechanisms of lncRNAs in periodontitis pathology by interacting with microRNAs. Finally, the potential clinical applications, current challenges, and prospects of lncRNAs as diagnostic and prognostic biomarkers and therapeutic targets for periodontitis disease are discussed.

Long Non-Coding RNAs in Diagnosis, Treatment, Prognosis, and Progression of Glioma: A State-of-the-Art Review

Glioma is the most common malignant central nervous system tumor with significant mortality and morbidity. Despite considerable advances, the exact molecular pathways involved in tumor progression are not fully elucidated, and patients commonly face a poor prognosis. Long non-coding RNAs (lncRNAs) have recently drawn extra attention for their potential roles in different types of cancer as well as non-malignant diseases. More than 200 lncRNAs have been reported to be associated with glioma. We aimed to assess the roles of the most investigated lncRNAs in different stages of tumor progression and the mediating molecular pathways in addition to their clinical applications. lncRNAs are involved in different stages of tumor formation, invasion, and progression, including regulating the cell cycle, apoptosis, autophagy, epithelial-to-mesenchymal transition, tumor stemness, angiogenesis, the integrity of the blood-tumor-brain barrier, tumor metabolism, and immunological responses. The well-known oncogenic lncRNAs, which are upregulated in glioma, are H19, HOTAIR, PVT1, UCA1, XIST, CRNDE, FOXD2-AS1, ANRIL, HOXA11-AS, TP73-AS1, and DANCR. On the other hand, MEG3, GAS5, CCASC2, and TUSC7 are tumor suppressor lncRNAs, which are downregulated. While most studies reported oncogenic effects for MALAT1, TUG1, and NEAT1, there are some controversies regarding these lncRNAs. Expression levels of lncRNAs can be associated with tumor grade, survival, treatment response (chemotherapy drugs or radiotherapy), and overall prognosis. Moreover, circulatory levels of lncRNAs, such as MALAT1, H19, HOTAIR, NEAT1, TUG1, GAS5, LINK-A, and TUSC7, can provide non-invasive diagnostic and prognostic tools. Modulation of expression of lncRNAs using antisense oligonucleotides can lead to novel therapeutics. Notably, a profound understanding of the underlying molecular pathways involved in the function of lncRNAs is required to develop novel therapeutic targets. More investigations with large sample sizes and increased focus on in-vivo models are required to expand our understanding of the potential roles and application of lncRNAs in glioma.

The Role of Sex-specific Long Non-coding RNAs in Cancer Prevention and Therapy

The functions of a large number of non-coding genes in human DNA have yet to be accurately identified. Long non-coding RNA (lncRNA) measuring 10 kb or less in length regulates transcription or post-transcriptional events. The lncRNAs have attracted increased attention of researchers in recent years. In this review, we summarize the recently published lncRNAs which are known to influence cancer development and progression. We also discuss recent studies investigating tumor-specific lncRNA expression. These lncRNAs provide very useful information that allows prediction of the degree of malignancy and a survival rate in cancer patients as clinically relevant biomarkers. Because symptoms and progression of cancer differ from onset to death between males and females, it is important to consider the gender of the patient when diagnosing cancer and predicting the progression. Considering the importance of gender difference, we also examine the influence of sex hormones involved in the expression and regulation of lncRNAs as biomarkers. Many of the lncRNAs examined in this review have been studied in cancers occurring in the female or male reproductive organs, but the association between lncRNAs and sex hormones has also been reported in common organs such as the lung, renal and colon. Although lncRNAs have not yet been widely used as definitive cancer indicators, recent studies have demonstrated the potential role of lncRNAs as biomarkers and therapeutic targets reflecting sex-specificity in a number of different cancers.

LncRNA signature in colorectal cancer

Colorectal cancer (CRC) is among the most frequent cancers and is associated with high mortality particularly when being diagnosed in advanced stages. Although several environmental and intrinsic risk factors have been identified, the underlying cause of CRC is not clear in the majority of cases. Several studies especially in the recent decade have pointed to the role of epigenetic factors in this kind of cancer. Long non-coding RNAs (lncRNAs) as important contributors in the epigenetic mechanisms are involved in the initiation, progression and metastasis of CRC. Tens of oncogenic lncRNAs and a lower number of tumor suppressor lncRNAs have been recently identified to be dysregulated in CRC cells and tissues. Notably, expressions of a number of these transcripts have been dysregulated in serum samples of CRC patients, providing a non-invasive route for detection of this kind of cancer. The involvement of lncRNAs in the regulation of autophagy has provided them the ability to modulate response of CRC cells to chemotherapeutic modalities. In the current manuscript, we review the studies which evaluated the role of lncRNAs in the pathogenesis and progression of CRC to appraise their application as diagnostic/ prognostic markers.

LncRNA GATA3‑AS1‑miR‑30b‑5p‑Tex10 axis modulates tumorigenesis in pancreatic cancer

Long noncoding RNAs (lncRNAs) have been widely recognized to play an important role in a variety of diseases. Abnormal regulation of lncRNA GATA3-antisense RNA 1 (AS1) occurs in several cancers, but whether it is involved in the progression of pancreatic cancer (PC) remains unknown. The present study aimed to investigate the biological effects of GATA3-AS1 in PC and to explore the underlying molecular mechanisms. Upregulation of GATA3-AS1 was revealed in PC tissues and cell lines. Knockdown of GATA3-AS1 in PANC-1 or AsPC-1 cells markedly reduced cell viability, cell proliferation, and cell invasion abilities, while cell apoptosis was increased. In addition, GATA3-AS1 knockdown suppressed the stemness of PANC-1 and AsPC-1 cells by decreasing the spheroid formation ability. A tumor xenograft in vivo assay demonstrated that GATA3-AS1 knockdown inhibited tumorigenicity of AsPC-1 cells. Furthermore, the microRNA (miR)-30b-5p downregulation and GATA3-AS1 upregulation were revealed in PC tissues and cell lines. Negative correlations were present between GATA3-AS1 and miR-30b-5p and between miR-30b-5p and testis-expressed protein 10 (Tex10) in the PC tissues, while GATA3-AS1 and Tex10 were positively correlated. GATA3-AS1 was then revealed to act as a competing endogenous RNA (ceRNA) for miR-30b-5p in regulating Tex10 expression. Moreover, the miR-30b-5p-Tex10 axis was confirmed to be involved in the regulation of biological effects of GATA3-AS1, including cell viability, cell proliferation, cell invasion, cell apoptosis, and cell stemness, as well as Wnt1/β-catenin signaling. Collectively, these data indicated that the GATA3-AS1-miR-30b-5p-Tex10 axis modulates tumorigenesis in PC, which may be associated with the Wnt/β-catenin signaling pathway.

LncRNA prostate androgen-regulated transcript 1 (PART 1) functions as an oncogene in osteosarcoma via sponging miR-20b-5p to upregulate BAMBI

Background

Osteosarcoma (OS) is an aggressive bone cancer that most commonly affects adolescents and children. Emerging studies have shown that long noncoding RNA (lncRNA) performs essential roles in the occurrence and development of many tumors. Prostate androgen-regulated transcript 1 (PART 1) has been reported as a tumor oncogene; despite this, the mechanisms underlying its involvement in OS are unclear.

Methods

OS and paired normal tissue samples were obtained, and gene expressions were detected by real time-quantitative polymerase chain reaction (RT-qPCR). The functions of PART 1 in OS cell proliferation, invasion, and migration were determined by Cell Counting Kit-8 (CCK-8) and Transwell assays. Furthermore, the binding sites of PART 1 and miR-20b-5p as well as those between miR-20b-5p and bone morphogenic protein and activin membrane-bound inhibitor homolog (BAMBI) were verified by bioinformatics analysis and dual-luciferase reporter assay.

Results

Our study found obvious overexpression of PART 1 in OS tissues and cells. Furthermore, PART 1 overexpression facilitated OS cell proliferation, invasion, and migration. Further mechanistic investigations revealed that PART 1 could sponge to miR-20b-5p, which was expressed at a low level in OS tissues and cells. Importantly, miR-20b-5p overexpression inhibited OS cell proliferation, invasion, and migration. Additionally, BAMBI was confirmed as a downstream gene of miR-20b-5p, and its expression was reversely modulated by miR-20b-5p and positively modulated by PART 1. Rescue experiments suggested that BAMBI was involved in PART 1-mediated promotion of OS progression.

Conclusions

PART 1 serves as a competing endogenous RNA to promote OS tumorigenesis via its regulation of the miR-20b-5p/BAMBI axis, which may provide a promising therapeutic biomarkers for OS patients.

The Role of the Z-DNA Binding Domain in Innate Immunity and Stress Granules

Both DNA and RNA can maintain left-handed double helical Z-conformation under physiological condition, but only when stabilized by Z-DNA binding domain (ZDBD). After initial discovery in RNA editing enzyme ADAR1, ZDBD has also been described in pathogen-sensing proteins ZBP1 and PKZ in host, as well as virulence proteins E3L and ORF112 in viruses. The host-virus antagonism immediately highlights the importance of ZDBD in antiviral innate immunity. Furthermore, Z-RNA binding has been shown to be responsible for the localization of these ZDBD-containing proteins to cytoplasmic stress granules that play central role in coordinating cellular response to stresses. This review sought to consolidate current understanding of Z-RNA sensing in innate immunity and implore possible roles of Z-RNA binding within cytoplasmic stress granules.

Inorganic arsenic influences cell apoptosis by regulating the expression of MEG3 gene

Arsenic is a wildly distributed carcinogen in the environment. Arsenic-induced apoptosis has been extensively studied in therapeutics and toxicology. LncRNA MEG3 has been extensively studied as apoptosis regulatory gene in recent years. However, it stays unclear regarding how the mechanism of MEG3 regulates arsenic-induced apoptosis. Our focus was to explore the effects of MEG3 on arsenic-induced apoptosis. MTS assay was used to test cell viability, and qRT-PCR was for the examination of gene expressions. The effect of the apoptosis and necrosis after knockdown MEG3 was detected with double staining. Our results demonstrated that MEG3 expression was positively correlated with the concentration of three arsenic species (inorganic arsenic (iAs), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA)) (p < 0.05). The ability of iAs to induce MEG3 expression was much higher compared with that induced by MMA and DMA. In addition, our experiments confirmed that MEG3 knockdown increased cell viability and arsenic-induced apoptosis, but cell viability decreased after iAs treatment. Moreover, LncRNA MEG3 regulated apoptosis via down-regulate API5 while up-regulate CASP7, CCND3 and APAF1. It is further proved that arsenic-induced apoptosis increased after the knockdown of MEG3, which regulates these genes. These findings provide experimental evidence and possible mechanisms for subsequent research on the effects of arsenic on health.

LncRNA XIST/miR-137 axis strengthens chemo-resistance and glycolysis of colorectal cancer cells by hindering transformation from PKM2 to PKM1

BACKGROUND

Glycolysis was an essential driver of chemo-resistance in colorectal cancer (CRC), albeit with limited molecular explanations.

OBJECTIVE

We strived to elucidate the involvement of lncRNA XIST/miR-137/PKM axis in chemo-tolerance and glycolysis of CRC.

METHODS

Altogether 212 pairs of tumor tissues and adjacent normal tissues were collected from CRC patients. Moreover, human CRC epithelial cell lines, including HT29, SW480, SW620 and LoVo, were purchased in advance, and their activity was estimated after transfection of si-XIST or miR-137 mimic. Furthermore, 5-FU/cisplatin-resistance of CRC cells was determined through MTT assay, and glycolytic potential of CRC cells was appraised based on oxygen consumption rate (OCR) and extracellular acidification rate (ECAR).

RESULTS

Highly-expressed XIST were predictive of severe symptoms and unfavorable 3-year survival of CRC patients (P< 0.05). Besides, silencing of XIST not only diminished proliferative, migratory and invasive power of CRC cells (P< 0.05), but also enhanced sensitivity of CRC cells responding to 5-FU/cisplatin (P< 0.05). Glycolytic potency of CRC cells was also undermined by si-XIST, with decreased maximal respiration and maximal glycolytic capacity in the si-XIST group as relative to NC group (P< 0.05). Nevertheless, miR-137 mimic attenuated the facilitating effect of pcDNA3.1-XIST on proliferation, migration, invasion, 5-FU/cisplatin-resistance and glycolysis of CRC cells (P< 0.05). Ultimately, ratio of PKM2 mRNA and PKM1 mRNA, despite being up-regulated by pcDNA3.1-XIST, was markedly lowered when miR-137 mimic was co-transfected (P< 0.05).

CONCLUSIONS

LncRNA XIST/miR-137 axis reinforced glycolysis and chemo-tolerance of CRC by elevating PKM2/PKM1 ratio, providing an alternative to boost chemo-therapeutic efficacy of CRC patients.

Clinical significance of long noncoding RNA maternally expressed gene 3 in acute promyelocytic leukemia

INTRODUCTION

Long noncoding RNA maternally expressed gene 3 (MEG3) expression was significantly decreased in acute myeloid leukemia (AML). However, its expression and clinical significance in acute promyelocytic leukemia (APL) remain unclear. Thus, the present study aimed to investigate the expression of MEG3 in APL and explore its clinical value.

METHODS

A total of 287 AML patients derived from The Cancer Genome Atlas (TCGA) and Vizome database were enrolled. A development and validation cohort, including APL, AML with AML1/ETO, and other types of AML patients and disease controls, from the First Affiliated Hospital of Nanchang University, were also enrolled in this study. The correlation between MEG3 expression and the clinicopathological features in APL was investigated. The diagnostic values of MEG3 expression in APL were analyzed by receiver operating characteristic (ROC) curves.

RESULT

In the development set, MEG3 expression was significantly increased in APL than AML with AML1/ETO, other types of AML, and disease controls, which was consistent with the results from the database analysis. MEG3 expression in APL was associated with age (P = .0053) but did not correlate with other clinicopathological features (P > .05). ROC curve analysis in the development set and diagnostic test analysis in the validation set suggested that MEG3 expression has a significant value in the diagnosis of APL. Furthermore, the expression of MEG3 decreased during the follow-up of patients with negative PML/RARα fusion gene.

CONCLUSION

MEG3 serves as a novel marker for the diagnosis of APL, evaluates the curative effect, and provides a novel direction for further research.

Long noncoding RNA MEG3 suppresses cell proliferation, migration and invasion, induces apoptosis and paclitaxel-resistance via miR-4513/PBLD axis in breast cancer cells

Breast cancer remains a general-threat event in the health of women. Currently, increasing records indicate that long non-coding RNA maternally expressed 3 (MEG3) plays a central role in breast cancer. The current research focused on the function of MEG3 in paclitaxel (PTX)-resistance and human breast cancer growth. Levels of MEG3, microRNA (miR)-4513, and phenazine biosynthesis-like domain-containing protein (PBLD) were evaluated using quantitative real-time polymerase chain reaction (qRT-PCR) or western blot assays. 3-(4.5-dimethylghiazol-2-yl)-2,5-diphenyltetrazolium Bromide (MTT) assay was performed to examine the IC₅₀ of PTX and cell proliferation in breast cancer cells. In addition, cell apoptosis was determined utilizing flow cytometry. Transwell was conducted to assay cell migration and invasion in MCF-7 and MDA-MB-231 cells. The interaction between miR-4513 and MEG3 or PBLD was expounded via dual-luciferase reporter assay. Levels of MEG3 and PBLD were decreased, but miR-4513 level was triggered in breast cancer tissues and cell lines. Overexpression of MEG3 could reinforce cell apoptosis, impede proliferation, migration, invasion, and the IC50 of PTX in breast cancer cells. Moreover, the impact of miR-4513 inhibitor on cell progression and PTX-resistance was overturned by MEG3 deficiency. Interestingly, miR-4513 mimic could abolish the role of PBLD upregulation in cell behaviors and PTX-resistance in MCF-7 and MDA-MB-231 cells. Finally, the expression of PBLD was co-modulated by miR-4513 and MEG3 in vitro. MEG3/miR-4513/PBLD axis modulated PTX-resistance and the development of breast cancer cells, which might provide a promising therapeutic strategy for breast cancer.

Exploring the Roles of lncRNAs in GBM Pathophysiology and Their Therapeutic Potential

Glioblastoma (GBM) remains the most devastating primary central nervous system malignancy with a median survival of around 15 months. The past decades of research have not yielded significant advancements in the treatment of GBM. In that same time, a novel class of molecules, long non-coding RNAs (lncRNAs), has been found to play a multitude of roles in cancer and normal biology. The increased accessibility of next generation sequencing technologies and the advent of lncRNA-specific microarrays have facilitated the study of lncRNA etiology. Molecular and computational methods can be applied to predict lncRNA function. LncRNAs can serve as molecular decoys, scaffolds, super-enhancers, or repressors. These molecules can serve as phenotypic switches for GBM cells at the expression and/or epigenetic levels. LncRNAs can affect stemness/differentiation, proliferation, invasion, survival, DNA damage response, and chromatin dynamics. Aberrant expression of these transcripts may facilitate therapy resistance, leading to tumor recurrence. LncRNAs could serve as novel theragnostic or prognostic biomarkers in GBM and other cancers. RNA-based therapeutics may also be employed to target lncRNAs as a novel route of treatment for primary or recurrent GBM. In this review, we explore the roles of lncRNAs in GBM pathophysiology and posit their novel therapeutic potential for GBM.

ELF1-activated FOXD3-AS1 promotes the migration, invasion and EMT of osteosarcoma cells via sponging miR-296-5p to upregulate ZCCHC3

Osteosarcoma (OS) is a malignant carcinoma often occurring in adolescents. The critical function of long non-coding RNAs (lncRNAs) in cancer arouses increasing attention. Nevertheless, the specific function of FOXD3 Antisense RNA 1 (FOXD3-AS1) in OS has not been understood yet. In this research, FOXD3-AS1 showed strengthened level in OS specimens and cell lines, and its deficiency restrained cell migration, invasion and epithelial-to-mesenchymal transition (EMT) in OS. Then, we confirmed the interaction of FOXD3-AS1 with microRNA-296-5p (miR-296-5p) and that miR-296-5p overexpression blocked OS cell migration, invasion and EMT. Besides, miR-296-5p targeted zinc finger CCHC-type containing 3 (ZCCHC3), and FOXD3-AS1 released ZCCHC3 via sequestering miR-296-5p. Moreover, rescue assays delineated that ZCCHC3 upregulation neutralized the inhibitory effect of FOXD3-AS1 depletion on in vitro behaviors and in vivo tumorigenesis in OS. In addition, E74 like ETS transcription factor 1 (ELF1) stimulated FOXD3-AS1 transcription, and ELF1 silence-suppressed malignant phenotypes of OS cells were offset by FOXD3-AS1 upregulation. Overall, present work elucidated that ELF1-activated FOXD3-AS1 aggravated cell migration, invasion and EMT in OS via absorbing miR-296-5p to augment ZCCHC3 expression, which might provide potential guidance for researchers to find effective targets for OS treatment.

Construction and Characterization of a Synergistic lncRNA-miRNA Network Reveals a Crucial and Prognostic Role of lncRNAs in Colon Cancer

Non-coding RNAs such as long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been found to be indispensable factors in carcinogenesis and cancer development. Numerous studies have explored the regulatory functions of these molecules and identified the synergistic interactions among lncRNAs or miRNAs, while those between lncRNAs and miRNAs remain to be investigated. In this study, we constructed and characterized an lncRNA–miRNA synergistic network following a four-step approach by integrating the regulatory pairs and expression profiles. The synergistic interactions with more shared regulatory mRNAs were found to have higher interactional intensity. Through the analysis of nodes in the network, we found that lncRNAs played roles that are more central and had similar synergistic interactions with their neighbors when compared with miRNAs. In addition, known colon adenocarcinoma (COAD)-related RNAs were found to be enriched in this synergistic network, with higher degrees, betweenness, and closeness. Finally, we proposed a risk score model to predict the clinical outcome for COAD patients based on two prognostic hub lncRNAs, MEG3 and ZEB1-AS1. Moreover, the hierarchical networks of these two lncRNAs could contribute to the understanding of the biological mechanism of tumorigenesis. For each lncRNA–miRNA interaction in the hub-related subnetwork and two hierarchical networks, we performed RNAup method to evaluate their binding energy. Our results identified two important lncRNAs with prognostic roles in colon cancer and dissected their regulatory mechanism involving synergistic interaction with miRNAs.

Khademul Islam AB. Perversely expressed long noncoding RNAs can alter host response and viral proliferation in SARS-CoV-2 infection

BACKGROUND

Regulatory roles of long noncoding RNAs (lncRNAs) during viral infection has become more evident in last decade, but are yet to be explored for SARS-CoV-2.

MATERIALS & METHODS

We analyzed RNA-seq dataset of SARS-CoV-2 infected lung epithelial cells to identify differentially expressed genes.

RESULTS

Our analyses uncover 21 differentially expressed lncRNAs broadly involved in cell survival and regulation of gene expression. These lncRNAs can directly interact with six differentially expressed protein-coding genes, and ten host genes that interact with SARS-CoV-2 proteins. Also, they can block the suppressive effect of nine microRNAs induced in viral infections.

CONCLUSION

Our investigation determines that deregulated lncRNAs in SARS-CoV-2 infection are involved in viral proliferation, cellular survival, and immune response, ultimately determining disease outcome.

Clinical diagnostic value of long non-coding RNAs in Colorectal Cancer: A systematic review and meta-analysis

Background: Histopathological diagnosis remains the gold standard for the diagnosis of cancer, including colorectal cancer, but it is infeasible when tumor tissue is not available. With the recognition of long non-coding RNAs (lncRNAs), the expression of lncRNAs in serum or tissue samples has been reported as a diagnosis method for some cancers, however, the diagnostic value of lncRNAs for colorectal cancer remains unclear.

Methods: A systematic review and meta-analysis were conducted. Eligible studies were identified through a comprehensive literature search in PubMed, PubMed Central, Web of Science, Embase, and Cochrane Library (up to May 05, 2020) according to the selection criteria. Meta-DiSc, Review Manager and STATA were used to analyze the association between lncRNAs expression and the diagnosis of colorectal cancer.

Results: Fifteen studies that analyzed the expression of 15 lncRNAs in 1434 CRC patients were included. The summary area under the curve (AUC) of lncRNA for the diagnosis efficacy between patients with and without CRC was estimated to be 0.8629, corresponding to a weighted sensitivity of 0.75 (95% CI: 0.72 - 0.77), specificity of 0.80 (95%CI: 0.78 - 0.82). Subgroup analysis illustrated that the AUC of blood-based detection of lncRNA showed 0.8820, pooled DOR: 18.57, while tissue-based analysis showed 0.8203, pooled DOR: 10.47. Blood-based tests were then divided into two categories, plasma-based and serum-based lncRNA testing. Results revealed that the AUC of serum-based detection was 0.9077, pooled DOR: 26.64, and plasma-based detection was 0.5000, pooled DOR: 11.80.

Conclusions: This meta-analysis indicates that the aberrantly expressed lncRNAs might serve as potential diagnostic biomarkers for CRC patients and blood-based lncRNA analysis is of higher diagnostic accuracy than tissue-based testing. Moreover, serum-based lncRNA testing achieved higher diagnostic efficacy than plasma-based analysis.

Evaluation of C5orf66-AS1 as a Potential Biomarker for Predicting Early Gastric Cancer and Its Role in Gastric Carcinogenesis

Background

Long non-coding RNAs (lncRNAs) participate in a series of pathological processes in tumorigenesis. Reports show that C5orf66-AS1, an antisense lncRNA, is expressed in various tumors. However, the role of C5orf66-AS1 in gastric cancer (GC) has not been fully clarified. The study focused on the expression patterns and serum level of C5orf66-AS1 in GC to explore its potential application in GC screening and diagnosis. The effects of C5orf66-AS1 on GC cells were also analyzed.

Methods

Tissue and serum samples were used for RNA isolation. Expression levels of C5orf66-AS1 in GC tissues, serum, and cell lines were detected using quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR). CCK-8, transwell, and wound healing assays were performed to determine the effects of C5orf66-AS1 on GC cell behavior.

Results

C5orf66-AS1 expression was downregulated in GC cells compared to that in adjacent normal tissues. Serum C5orf66-AS1 levels were significantly lower in GC patients than in superficial gastritis (GS) and atrophic gastritis (GA) patients. Low serum expression of C5orf66-AS1 was associated with an increased risk of gastric dysplasia (GD) and GC. Receiver operating characteristic curve results showed that the area under curve (AUC) for GC was 0.688, with a sensitivity and specificity of 77.5% and 53.6%, respectively. For the GD + early gastric cancer (ECG) group, the AUC was 0.789, with a sensitivity and specificity of 85.15% and 62.86%, respectively. Correlation analyses of clinicopathological parameters showed that serum C5orf66-AS1 was predominantly associated with Lauren type, TNM stages, pTNM stages, and vessel tumor emboli. Additionally, in vitro overexpression of C5orf66-AS1 in AGS cells inhibited cell proliferation, migration, and invasion.

Conclusion

Decreased expression levels of serum C5orf66-AS1 can be utilized for diagnosis of GC, especially for early diagnosis. The low level of serum C5orf66-AS1 indicated poor biological behavior of tumors in GC patients. In addition, C5orf66-AS1 can inhibit GC cell proliferation, migration, and invasion.

Exploring prognostic potential of long noncoding RNAs in colorectal cancer based on a competing endogenous RNA network

BACKGROUND

Colorectal cancer (CRC) is one of the most prevalent tumors worldwide. Recently, long noncoding RNAs (lncRNAs) have been shown to influence tumorigenesis and tumor progression by acting as competing endogenous RNAs (ceRNAs). It is difficult to extract prognostic lncRNAs and useful bioinformation from most ceRNA networks constructed previously.

AIM

To construct a prognostic related ceRNA regulatory network and lncRNA related signature based on risk score in CRC.

METHODS

RNA transcriptome profile and clinical information of 506 CRC patients were downloaded from the Cancer Genome Atlas database. R packages and Perl program were used for data processing. Cox regression analysis was used for prognostic model construction. Quantitative real-time polymerase chain reaction was used to detect the expression of lncRNAs.

RESULTS

A prognostic-related ceRNA network was constructed, including 9 lncRNAs, 44 mRNAs, and 30 miRNAs. In addition, a four-lncRNA model was constructed using multivariate Cox regression analysis, which could be an independent prognostic model in CRC. The risk score for each patient was calculated, and the 506 patients were divided into high and low-risk groups (253 for each group) based on the median risk score. The results of the survival analysis showed that patients with a high-risk score had a poor survival rate. Furthermore, the predictive value of the four-lncRNA model was evaluated in GSE38832. Patient survival probabilities could be better predicted when combing the risk score and clinical features. Gene Set Enrichment Analysis results verified that a number of cancer-related signaling pathways were enriched with a high-risk score in CRC. Finally, we validated a novel lncRNA (LINC00488) using quantitative real-time polymerase chain reaction in 22 paired CRC patient tumor tissues compared to adjacent non-tumor tissues.

CONCLUSION

The four-lncRNA model could give better predictive value for CRC patients. Our understanding of the lncRNA-related ceRNA regulatory mechanism could provide a potential diagnostic indicator for CRC patients.

Long Non-coding RNA MEG3 Activated by Vitamin D Suppresses Glycolysis in Colorectal Cancer via Promoting c-Myc Degradation

Colorectal cancer (CRC), a common tumor, is characterized by a high mortality rate. Long non-coding RNA maternally expressed gene 3 (MEG3) serves a regulatory role in the carcinogenesis and progression of several types of cancer; however, its role in CRC remains largely unknown. The aim of this study was to explore the regulatory role and mechanism(s) of MEG3 in CRC. The Warburg effect or aerobic glycolysis is characteristic of the metabolism of tumor cells. To determine the effect of MEG3 on glycolysis of CRC cells, we used an XF analyzer to perform glycolysis stress test assays and found that overexpression of MEG3 significantly inhibited glycolysis, glycolytic capacity, as well as lactate production in CRC cells, whereas knockdown of MEG3 produced the opposite effect. Mechanistically, overexpression of MEG3 induced ubiquitin-dependent degradation of c-Myc and inhibited c-Myc target genes involved in the glycolysis pathway such as lactate dehydrogenase A, pyruvate kinase muscle 2, and hexokinase 2. Moreover, we found that MEG3 can be activated by vitamin D and vitamin D receptor (VDR). Clinical data demonstrated that MEG3 was positively associated with serum vitamin D concentrations in patients with CRC. We found that 1,25(OH)₂D₃ treatment increased MEG3 expression, and knockdown of VDR abolished the effect of MEG3 on glycolysis. These results indicate that vitamin D-activated MEG3 suppresses aerobic glycolysis in CRC cells via degradation of c-Myc. Thus, vitamin D may have therapeutic value in the treatment of CRC.

Noncoding RNAs in inflammation and colorectal cancer

Despite advanced clinical treatments, mortality in patients with metastatic colorectal cancer (CRC) remains high. Three critical determinants in CRC progression include the epithelial proliferation checkpoints, epithelial-to-mesenchymal transition (EMT) and inflammatory cytokines in the tumour microenvironment. Genes involved in these three processes are regulated at the transcriptional and post-transcriptional level. Recent studies revealed previously unappreciated roles of non-coding ribonucleic acids (ncRNAs) in modulating the proliferation checkpoints, EMT, and inflammatory gene expression in CRC. In this review, we will discuss the mechanisms underlying the roles of ncRNAs in CRC as well as examine future perspectives in this field. Better understanding of ncRNA biology will provide novel targets for future therapeutic development.

LncRNA, a novel target biomolecule, is involved in the progression of colorectal cancer

Colorectal cancer is one of the most commonly diagnosed malignancies among males and females worldwide. Although China is a country with a low incidence of colorectal cancer, with the improvement of China's economy and lifestyle changes, the incidence rate in China has generally increased in recent years, and the morbidity and mortality of colorectal cancer rank fifth among those of all malignant tumours. Furthermore, despite recent improvements in screening strategies and treatments for colorectal cancer, the prognosis of advanced colorectal cancer is still poor, mainly due to the recurrence or distant metastasis of this disease. Thus, colorectal cancer still seriously threatens the health and life of people and is a major public health problem worthy of further study. Recently, accumulating evidence has revealed that colorectal carcinogenesis might be a multistep process driven by progressive genetic abnormalities, including changes in lncRNA expression. Moreover, a large number of studies have discovered and studied the abnormal expression of lncRNAs in colorectal cancer, providing a promising target for the diagnosis and treatment of colorectal cancer, which will promote human understanding of the pathogenesis of colorectal cancer and improve diagnosis and treatment. Therefore, in the present review, we mainly summarize the present status of colorectal cancer, the characteristics, functions and clinical perspectives of lncRNAs, and the current therapeutic methods used for colorectal cancer, especially the application of lncRNAs in the treatment of colorectal cancer. It is hoped that this review will give readers a new understanding of the roles of lncRNAs in colorectal cancer.