The combination of circulating long noncoding RNAs AK001058, INHBA-AS1, MIR4435-2HG, and CEBPA-AS1 fragments in plasma serve as diagnostic markers for gastric cancer

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

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

Biological Roles and Pathogenic Mechanisms of LncRNA MIR4435-2HG in Cancer: A Comprehensive Review

The long non-coding RNA MIR4435-2HG has been confirmed to play a crucial regulatory role in various types of tumors. As a novel type of non-coding RNA, MIR4435-2HG plays a key role in regulating the expression of tumor-related genes, interfering with cellular signaling pathways, and affecting tumor immune evasion. Its unique structure allows it to regulate the expression of various tumor-related genes through different pathways, participating in the regulation of tumor signaling pathways, such as regulating the expression of oncogenes and tumor suppressor genes, influencing the biological behaviors of proliferation, metastasis, and apoptosis in tumors. Numerous studies have found a high expression of MIR4435-2HG in various tumor tissues, closely related to the clinical pathological characteristics of tumors, such as staging, lymph node metastasis and prognosis. Some studies have discovered that MIR4435-2HG can regulate the sensitivity of tumor cells to chemotherapy drugs, affecting tumor cell drug resistance. This provides new insights into overcoming tumor drug resistance by regulating MIR4435-2HG. Therefore, studying its molecular mechanisms, expression regulation, and its relationship with the clinical features of tumors is of great significance for revealing the mechanisms of tumor occurrence and developing new therapeutic targets.

Abnormally Expressed lncRNAs as Potential Biomarkers for Gastric Cancer Risk: A Diagnostic Meta-Bioinformatics Analysis

Background and Aims

Abnormal expression of lncRNAs is relevant to the occurrence and development of gastric cancer (GC), but the significance remains inconclusive. We performed a diagnostic meta-bioinformatics analysis to elucidate the association between lncRNA expression and GC risk.

Methods

Published datasets were selected from PubMed, Embase, CNKI, and Web of Science, up to 1st December 2021. The pooled sensitivity (SEN), specificity (SPE), positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the curve (AUC) were calculated to evaluate the diagnostic value. RNA sequencing data were downloaded for validation.

Results

54 studies with 4671 patients and 4652 matched controls were included in the meta-analysis. The pooled SEN, SPE, PLR, NLR, DOR, and AUC were 0.71, 0.76, 2.9, 0.39, 8, and 0.79, respectively. Subgroup analyses showed that the DOR and AUC of intergenic lncRNAs, circulating lncRNAs, larger sample size (>200), and high-quality (NOS score ≥ 7) groups were superior to antisense lncRNAs, tissue lncRNAs, smaller sample size (≤200), and low-quality (NOS score < 7) groups, respectively. However, only circulating lncRNAs had significantly higher diagnostic utility than that tissue lncRNAs. Nine differentially expressed lncRNAs in the meta-analysis were verified in TCGA-STAD. PVT1 was the most effective single lncRNA, with AUC of 0.949, SEN of 0.808, and SPE of 0.969, while PVT1 and C5orf66-AS1 were the most effective combination, with AUC of 0.972, SEN of 0.941, and SPE of 0.937.

Conclusion

Abnormally expressed lncRNAs, especially circulating lncRNAs, might be potential diagnostic biomarkers for GC risk. A novel combined model of lncRNAs might achieve better GC diagnosis performance.

Identification of potential hub genes of gastric cancer

BACKGROUND

Gastric cancer (GC) is a malignant tumor originated from gastric mucosa epithelium. It is the third leading cause of cancer mortality in China. The early symptoms are not obvious. When it is discovered, it has developed to the advanced stage, and the prognosis is poor. In order to screen for potential genes for GC development, this study obtained GSE118916 and GSE109476 from the gene expression omnibus (GEO) database for bioinformatics analysis.

METHODS

First, GEO2R was used to identify differentially expressed genes (DEG) and the functional annotation of DEGs was performed by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. The Search Tool for the Retrieval of Interacting Genes (STRING) tool was used to construct protein-protein interaction (PPI) network and the most important modules and hub genes were mined. Real time quantitative polymerase chain reaction assay was performed to verify the expression level of hub genes.

RESULTS

A total of 139 DEGs were identified. The functional changes of DEGs are mainly concentrated in the cytoskeleton, extracellular matrix and collagen synthesis. Eleven genes were identified as core genes. Bioinformatics analysis shows that the core genes are mainly enriched in many processes related to cell adhesion and collagen.

CONCLUSION

In summary, the DEGs and hub genes found in this study may be potential diagnostic and therapeutic targets.

Transcriptomic Analyses Reveal Long Non-Coding RNA in Peripheral Blood Mononuclear Cells as a Novel Biomarker for Diagnosis and Prognosis of Hepatocellular Carcinoma

Novel biomarkers are highly required for the diagnosis and predicting prognosis of hepatocellular carcinoma (HCC). In this study, we investigated the profiles of long non-coding RNAs (lncRNAs) obtained from the peripheral blood mononuclear cells (PBMCs) of patients with HCC and PBMCs from a co-culture model using transcriptomic analysis. The differentially expressed lncRNAs (DElncRNAs) were then characterized and integrated as cancer-induced lncRNAs. Among them, three up-regulating DElncRNAs including MIR4435-2HG, SNHG9 and lnc-LCP2-1 and one down-regulating, lnc-POLD3-2, were identified. The functional analysis showed that these enriched lncRNAs were mainly associated with carcinogenesis and immune responses. Following further validation in PBMCs samples (100 HBV-related HCC, 100 chronic hepatitis B and 100 healthy controls), MIR4435-2HG, lnc-POLD3-2 and their combination were revealed to be sensitive biomarkers in discriminating HCC from non-HCC (AUROC = 0.78, 0.80, and 0.87, respectively), particularly among individuals with normal serum alpha-fetoprotein levels. Additionally, high circulating SNHG9 expression was shown to be an independent prognostic factor of overall survival in patients with HCC. These results indicate that determining these lncRNAs in PBMCs could serve as novel diagnostic and prognostic biomarkers for HBV-related HCC.

Long non-coding RNA MIR4435-2HG: a key molecule in progression of cancer and non-cancerous disorders

MIR4435-2HG (LINC00978) is a long non-coding RNA (lncRNA) that acts as an oncogene in almost all cancers. This lncRNA participates in the molecular cascades involved in other disorders such as coronary artery diseases, osteonecrosis, osteoarthritis, osteoporosis, and periodontitis. MIR4435-2HG exerts its functions via the spectrum of different mechanisms, including inhibition of apoptosis, sponging microRNAs (miRNAs), promoting cell proliferation, increasing cell invasion and migration, and enhancing epithelial to mesenchymal transition (EMT). MIR4435-2HG can regulate several signaling pathways, including Wnt, TGF-β/SMAD, Nrf2/HO-1, PI3K/AKT, MAPK/ERK, and FAK/AKT/β‑catenin signaling pathways; therefore, it can lead to tumor progression. In the present review, we aimed to discuss the potential roles of lncRNA MIR4435-2HG in developing cancerous and non-cancerous conditions. Due to its pivotal role in different disorders, this lncRNA can serve as a potential biomarker in future investigations. Moreover, it may serve as a potential therapeutic target for the treatment of various diseases.

Navigating the genomic instability mine field of osteosarcoma to better understand implications of non-coding RNAs

Osteosarcoma is one of the most genomically complex cancers and as result, it has been difficult to assign genomic aberrations that contribute to disease progression and patient outcome consistently across samples. One potential source for correlating osteosarcoma and genomic biomarkers is within the non-coding regions of RNA that are differentially expressed. However, it is unsurprising that a cancer classification that is fraught with genomic instability is likely to have numerous studies correlating non-coding RNA expression and function have been published on the subject. This review undertakes the formidable task of evaluating the published literature of noncoding RNAs in osteosarcoma. This is not the first review on this topic and will certainly not be the last. The review is organized with an introduction into osteosarcoma and the epigenetic control of gene expression before reviewing the molecular function and expression of long non-coding RNAs, circular RNAs, and short non-coding RNAs such as microRNAs, piwi RNAs, and short-interfering RNAs. The review concludes with a review of the literature and how the biology of non-coding RNAs can be used therapeutically to treat cancers, especially osteosarcoma. We conclude that non-coding RNA expression and function in osteosarcoma is equally complex to understanding the expression differences and function of coding RNA and proteins; however, with the added lens of both coding and non-coding genomic sequence, researchers can begin to identify the patterns that consistently associate with aggressive osteosarcoma.

MIR4435-2HG：A tumor-associated long non-coding RNA

BACKGROUND

It is well known that the changes in the expression level of LncRNA can affect the progression of tumors, which has caused a great upsurge of research in recent years. More and more LncRNA has been proved to take effect on a series of cancers and can promote tumor growth, migration and invasion. In this review, we aim to clarify the pathophysiological functions of LncRNA -MIR4435-2 HG in multiple tumors can be elucidated.

METHODS

By consulting the literature through PubMed, this paper summarizes the relationship between MIR4435-2HG and tumor and its role in the occurrence and development of cancer, and also expounds the specific molecular mechanism of the effect of MIR4435-2HG on cancer.

RESULTS

MIR4435-2HG can function as an oncogene in a variety of cancers. The expression level was abnormally elevated in a series of cancers, consisting of melanoma gastric cancer, head and neck squamous cell carcinoma, oral squamous cell carcinoma, lung cancer, cervical cancer, prostate carcinoma, ovarian cancer, breast cancer, hepatocellular Carcinoma, clear cell renal cell carcinoma malignant, glioma and colorectal cancer. Moreover, MIR4435-2HG is related to the poor prognosis of a variety of cancers. MIR4435-2HG can also affect tumor proliferation, invasion and apoptosis. In addition, MIR4435-2HG can also enhance the metabolic function of myeloid dendritic cells of elite HIV-1 controllers.

CONCLUSION

MIR4435-2HG affects the development of a variety of cancers. It can act as a clinical marker for early tumor diagnosis and takes effects to tumor targeted therapy.

Overview and Update on Extracellular Vesicles: Considerations on Exosomes and Their Application in Modern Medicine

In recent years, there has been a rapid growth in the knowledge of cell-secreted extracellular vesicle functions. They are membrane enclosed and loaded with proteins, nucleic acids, lipids, and other biomolecules. After being released into the extracellular environment, some of these vesicles are delivered to recipient cells; consequently, the target cell may undergo physiological or pathological changes. Thus, extracellular vesicles as biological nano-carriers, have a pivotal role in facilitating long-distance intercellular communication. Understanding the mechanisms that mediate this communication process is important not only for basic science but also in medicine. Indeed, extracellular vesicles are currently seen with immense interest in nanomedicine and precision medicine for their potential use in diagnostic, prognostic, and therapeutic applications. This paper aims to summarize the latest advances in the study of the smallest subtype among extracellular vesicles, the exosomes. The article is divided into several sections, focusing on exosomes' nature, characteristics, and commonly used strategies and methodologies for their separation, characterization, and visualization. By searching an extended portion of the relevant literature, this work aims to give a quick outline of advances in exosomes' extensive nanomedical applications. Moreover, considerations that require further investigations before translating them to clinical applications are summarized.

Conventional and Nonconventional Sources of Exosomes-Isolation Methods and Influence on Their Downstream Biomedical Application

Despite extensive study of extracellular vesicles (EVs), specifically exosomes (EXs) as biomarkers, important modulators of physiological or pathological processes, or therapeutic agents, relatively little is known about nonconventional sources of EXs, such as invertebrate or plant EXs, and their uses. Likewise, there is no clear information on the overview of storage conditions and currently used isolation methods, including new ones, such as microfluidics, which fundamentally affect the characterization of EXs and their other biomedical applications. The purpose of this review is to briefly summarize conventional and nonconventional sources of EXs, storage conditions and typical isolation methods, widely used kits and new "smart" technologies with emphasis on the influence of isolation techniques on EX content, protein detection, RNA, mRNA and others. At the same time, attention is paid to a brief overview of the direction of biomedical application of EXs, especially in diagnostics, therapy, senescence and aging and, with regard to the current situation, in issues related to Covid-19.

A genome-wide association study in a large community-based cohort identifies multiple loci associated with susceptibility to bacterial and viral infections

There is limited data on host-specific genetic determinants of susceptibility to bacterial and viral infections. Genome-wide association studies using large population cohorts can be a first step towards identifying patients prone to infectious diseases and targets for new therapies. Genetic variants associated with clinically relevant entities of bacterial and viral infections (e.g., abdominal infections, respiratory infections, and sepsis) in 337,484 participants of the UK Biobank cohort were explored by genome-wide association analyses. Cases (n = 81,179) were identified based on ICD-10 diagnosis codes of hospital inpatient and death registries. Functional annotation was performed using gene expression (eQTL) data. Fifty-seven unique genome-wide significant loci were found, many of which are novel in the context of infectious diseases. Some of the detected genetic variants were previously reported associated with infectious, inflammatory, autoimmune, and malignant diseases or key components of the immune system (e.g., white blood cells, cytokines). Fine mapping of the HLA region revealed significant associations with HLA-DQA1, HLA-DRB1, and HLA-DRB4 locus alleles. PPP1R14A showed strong colocalization with abdominal infections and gene expression in sigmoid and transverse colon, suggesting causality. Shared significant loci across infections and non-infectious phenotypes in the UK Biobank cohort were found, suggesting associations for example between SNPs identified for abdominal infections and CRP, rheumatoid arthritis, and diabetes mellitus. We report multiple loci associated with bacterial and viral infections. A better understanding of the genetic determinants of bacterial and viral infections can be useful to identify patients at risk and in the development of new drugs.

Gastric cancer: An epigenetic view

Gastric cancer (GC) poses a serious threat worldwide with unfavorable prognosis mainly due to late diagnosis and limited therapies. Therefore, precise molecular classification and search for potential targets are required for diagnosis and treatment, as GC is complicated and heterogeneous in nature. Accumulating evidence indicates that epigenetics plays a vital role in gastric carcinogenesis and progression, including histone modifications, DNA methylation and non-coding RNAs. Epigenetic biomarkers and drugs are currently under intensive evaluations to ensure efficient clinical utility in GC. In this review, key epigenetic alterations and related functions and mechanisms are summarized in GC. We focus on integration of existing epigenetic findings in GC for the bench-to-bedside translation of some pivotal epigenetic alterations into clinical practice and also describe the vacant field waiting for investigation.

Prognostic Role of Long Noncoding RNAs in Oral Squamous Cell Carcinoma: A Meta-Analysis

Long noncoding RNAs (lncRNAs) have emerged as critical regulators of tumor progression, and lncRNA expression levels could serve as a potential molecular biomarker for the prognosis and diagnosis of some cancers. However, the prognostic value of lncRNAs in oral squamous cell carcinoma (OSCC) remains unclear. Thus, a meta-analysis was conducted to explore the potential prognostic value of lncRNAs in OSCC. We systematically searched PubMed, EBSCO, Web of Science, and Elsevier from 2005 to 2021 to identify all published studies that reported the association between lncRNAs and prognosis in OSCC. Then, we used meta-analytic methods to identify the actual effect size of lncRNAs on cancer prognosis. The hazard ratios (HRs) with 95% confidence intervals (95% CIs) were calculated to assess the strength of the association. The reliability of those results was then examined using measures of heterogeneity and testing for selective reporting biases. According to the inclusion and exclusion criteria, a total of 17 studies were eligible in our meta-analysis, involving 1384 Asian patients. The results identified a statistically significant association of high lncRNA expression with poor overall survival [adjusted pooled hazard ratio (AHR) = 1.52; 95% confidence interval (CI): [1.26–1.84], p ≤ 0.001]. The present meta-analysis demonstrated that lncRNA expression might be used as a predictive prognostic biomarker for Asian patients with OSCC.

Identification of Combinations of Plasma lncRNAs and mRNAs as Potential Biomarkers for Precursor Lesions and Early Gastric Cancer

Patients with gastric cancer (GC) are usually first diagnosed at an advanced stage due to the absence of obvious symptoms at an early GC (EGC) stage. Therefore, it is necessary to identify an effective screening method to detect precursor lesions of GC (PLGC) and EGC to increase the 5-year survival rate of patients. Cell-free RNA, as a biomarker, has shown potential in early diagnosis, personalised treatment, and prognosis of cancer. In this study, six RNAs (CEBPA-AS1, INHBA-AS1, AK001058, UCA1, PPBP, and RGS18) were analysed via real-time quantitative polymerase chain reaction (RT-qPCR) using the plasma of patients with EGC and PLGC to identify diagnostic biomarkers. The receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic accuracy. Among the six RNAs, four lncRNAs (CEBPA-AS1, INHBA-AS1, AK001058, and UCA1) were upregulated and two mRNAs (PPBP and RGS18) were downregulated in the plasma of patients with PLGC and EGC. According to the findings of the ROC analysis, the four-RNA combination of INHBA-AS1, AK001058, UCA1, and RGS18 had the highest area under the curve (AUC) value for determining risk of GC in patients with PLGC and the six-RNA combination including CEBPA-AS1, INHBA-AS1, AK001058, UCA1, PPBP, and RGS18 had the highest AUC value for determining the risk of GC in patients with EGC. The results suggest the potential usefulness of noninvasive biomarkers for the molecular diagnosis of GC at earlier stages.

LncRNA CEBPA-AS1 alleviates cerebral ischemia-reperfusion injury by sponging miR-340-5p regulating APPL1/LKB1/AMPK pathway

Long non-coding RNAs (lncRNAs) regulate neurological damage in cerebral ischemia-reperfusion injury (CIRI). This study aimed to investigate the biological roles of lncRNA CEBPA-AS1 in CIRI. Middle cerebral artery occlusion and ischemia-reperfusion injury (MCAO/IR) rat model and oxygen-glucose deprivation and reoxygenation (OGD/R) cell lines were generated; the expression of CEBPA-AS1 was evaluated by qRT-PCR. The effects of CEBPA-AS1 on cell apoptosis and nerve damage were examined. The downstream microRNA (miRNA) and mRNA of CEBPA-AS1 were predicted and verified. We found that overexpression of CEBPA-AS1 could attenuate MCAO/IR-induced nerve damage and neuronal apoptosis in the rat model. Knockdown of CEBPA-AS1 aggravated cell apoptosis and enhanced the production of LDH and MDA in the OGD/R cells. Upon examining the molecular mechanisms, we found that CEBPA-AS1 stimulated APPL1 expression by combining with miR-340-5p, thereby regulating the APPL1/LKB1/AMPK pathway. In the rescue experiments, CEBPA-AS1 overexpression was found to attenuate OGD/R-induced cell apoptosis and MCAO/IR induced nerve damage, while miR-340-5p reversed these effects of CEBPA-AS1. In conclusion, CEBPA-AS1 could decrease CIRI by sponging miR-340-5, regulating the APPL1/LKB1/AMPK pathway.

Long non-coding RNAs: Biogenesis, functions, and clinical significance in gastric cancer

Gastric cancer (GC) is one of the most prevalent malignant tumor types and the third leading cause of cancer-related death worldwide. Its morbidity and mortality are very high due to a lack of understanding about its pathogenesis and the slow development of novel therapeutic strategies. Long non-coding RNAs (lncRNAs) are a class of non-coding RNAs with a length of more than 200 nt. They play crucial roles in a wide spectrum of physiological and pathological processes by regulating the expression of genes involved in proliferation, differentiation, apoptosis, cell cycle, invasion, metastasis, DNA damage, and carcinogenesis. The aberrant expression of lncRNAs has been found in various cancer types. A growing amount of evidence demonstrates that lncRNAs are involved in many aspects of GC pathogenesis, including its occurrence, metastasis, and recurrence, indicating their potential role as novel biomarkers in the diagnosis, prognosis, and therapeutic targets of GC. This review systematically summarizes the biogenesis, biological properties, and functions of lncRNAs and highlights their critical role and clinical significance in GC. This information may contribute to the development of better diagnostics and treatments for GC.

A proposed Information-Based modality for the treatment of cancer

Treatment modalities for cancer involve physical manipulations such as surgery, immunology, radiation, chemotherapy or gene editing. This is a proposal for an information-based modality. This modality does not change the internal state of the cancer cell directly - instead, the cancer cell is manipulated by giving it information to instruct the cell to perform an action. This modality is based on a theory of Structure Encoding in DNA, where information about body part structure controls the epigenetic state of cells in the process of development from pluripotent cells to fully differentiated cells. It has been noted that cancer is often due to errors in morphogenetic differentiation accompanied by associated epigenetic processes. This implies a model of cancer called the Epigenetic Differentiation Model. A major feature of the Structure Encoding Theory is that the characteristics of the differentiated cell are affected by inter-cellular information passed in the tissue microenvironment, which specifies the exact location of a cell in a body part structure. This is done by exosomes that carry fragments of long non-coding RNA and transposons, which convey structure information. In the normal process of epigenetic differentiation, the information passed may lead to apoptosis due to the constraints of a particular body part structure. The proposed treatment involves determining what structure information is being passed in a particular tumor, then adding artificial exosomes that overwhelm the current information with commands for the cells to go into apoptosis.

Polygenic Risk Scores for Prediction of Gastric Cancer Based on Bioinformatics Screening and Validation of Functional lncRNA SNPs

INTRODUCTION

Single-nucleotide polymorphisms (SNPs) are used to stratify the risk of gastric cancer. However, no study included gastric cancer-related long noncoding RNA (lncRNA) SNPs into the risk model for evaluation. This study aimed to replicate the associations of 21 lncRNA SNPs and to construct an individual risk prediction model for gastric cancer.

METHODS

The bioinformatics method was used to screen gastric cancer-related lncRNA functional SNPs and verified in population. Gastric cancer risk prediction models were constructed using verified SNPs based on polygenic risk scores (PRSs).

RESULTS

Twenty-one SNPs were screened, and the multivariate unconditional logistic regression analysis showed that 14 lncRNA SNPs were significantly associated with gastric cancer. In the distribution of genetic risk score in cases and controls, the mean value of PRS in cases was higher than that in controls. Approximately 20.1% of the cases was caused by genetic variation (P = 1.9 × 10-34) in optimal PRS model. The individual risk of gastric cancer in the lowest 10% of PRS was 82.1% (95% confidence interval [CI]: 0.102, 0.314) lower than that of the general population. The risk of gastric cancer in the highest 10% of PRS was 5.75-fold that of the general population (95% CI: 3.09, 10.70). The introduction of family history of tumor (area under the curve, 95% CI: 0.752, 0.69-0.814) and Helicobacter pylori infection (area under the curve, 95% CI: 0.773, 0.702-0.843) on the basis of PRS could significantly improve the recognition ability of the model.

DISCUSSION

PRSs based on lncRNA SNPs could identify individuals with high risk of gastric cancer and combined with risk factors could improve the stratification.

Identification of lncRNA-associated competing endogenous RNA networks for occurrence and prognosis of gastric carcinoma

Background

Gastric cancer (GC) is one of the common digestive malignancies worldwide and causes a severe public health issue. So far, the underlying mechanisms of GC are largely unclear. Thus, we aim to identify the long non‐coding RNA (lncRNA)‐associated competing endogenous RNA (ceRNA) for GC.

Methods

TCGA database was downloaded and used for the identification of differentially expressed (DE) lncRNAs, miRNAs, and mRNAs, respectively. Then, the ceRNA network was constructed via multiple online datasets and approaches. In addition, various in vitro assays were carried out to validate the effect of certain hub lncRNAs.

Results

We constructed a ceRNA network, including 76 lncRNAs, 18 miRNAs, and 159 mRNAs, which involved multiple critical pathways. Next, univariate and multivariate analysis demonstrated 11 lncRNAs, including LINC02731, MIR99AHG, INHBA‐AS1, CCDC144NL‐AS1, VLDLR‐AS1, LIFR‐AS1, A2M‐AS1, LINC01537, and LINC00702, and were associated with OS, and nine of those lncRNAs were considered as hub lncRNAs involved in the sub‐ceRNA network. The in vitro assay indicated two lncRNAs, INHBA‐AS1 and CCDC144NL‐AS1, which were positively related to the GC aggressive features, including proliferation, invasion, and migration.

Conclusions

We identified nine hub lncRNAs and the associated ceRNA network related to the prognosis of GC, and then validated two out of them as promising oncogenes in GC.

Aberrant expression of lncRNAs SNHG6, TRPM2-AS1, MIR4435-2HG, and hypomethylation of TRPM2-AS1 promoter in colorectal cancer

Accumulating evidence has indicated that deregulation of lncRNAs plays essential roles in colorectal cancer (CRC) carcinogenesis. The goal of this study was to analyze the expression of lncRNAs in colorectal cancer and their association with clinicopathological variables. Bioinformatics analysis of published CRC microarray data was performed to identify the important lncRNAs. The expression levels of candidate genes were assessed in the human colon cancer/normal cell lines, CRC, adenomatous colorectal polyps, and their marginal tissues by qRT-PCR. Moreover, the methylation status of the TRPM2-AS1 promoter was studied using qMSP assay. Furthermore, we investigated the molecular mechanisms of these lncRNAs in CRC progression using in silico analysis. Microarray analysis revealed that lncRNAs SNHG6, MIR4435-2HG, and TRPM2-AS1 were upregulated in CRC. These results were validated in colon cell lines. Moreover, qRT-PCR showed that the expression levels of SNHG6 and TRPM2-AS1 were upregulated in the colorectal tumor tissues compared with their paired tissues. Nonetheless, there was no significant increase in MIR4435-2HG expression in CRC samples. Furthermore, we observed a significant hypomethylation of TRPM2-AS1 promoter and its activation in CRC tissues. By in silico analysis, we found that the lncRNAs upregulation could promote proliferation and drug resistance of colorectal cancer cells via miRNAs sponging and modulation of their targets expression. In conclusion, based on our results upregulation of SNHG6 and TRPM2-AS1, and hypomethylation of TRPM2-AS1 promoter might be considered as potential diagnostic biomarkers for CRC initiation and development.

Immune-Related Gene Expression Analysis Revealed Three lncRNAs as Prognostic Factors for Colon Cancer

Colorectal cancer (CRC) is one of the most common cancers. Almost 80% of CRC cases are colon adenocarcinomas (COADs). Several studies have indicated the role of immunotherapy in the treatment of various cancers. Our study aimed to identify immune-related long non-coding RNAs (lncRNAs) and to use them to construct a risk assessment model for evaluating COAD prognosis. Using differential expression, correlation, and Cox regression analyses, we identified three immune-related differentially expressed lncRNAs (IR-DELs) and used them to construct a risk assessment model. The area under the curve (AUC) for each receiver operating characteristic (ROC) curve at 3-, 5-, and 10-years were greater than 0.6. In addition, the risk assessment model was correlated with several immune cells and factors. The three IR-DELs (AC124067.4, LINC02604, and MIR4435-2HG) identified in this study can be used to predict outcomes for patients with COAD and might help in identifying those who can benefit from anti-tumor immunotherapy.

RNA Interference and Nanotechnology: A Promising Alliance for Next Generation Cancer Therapeutics

Cancer is a significant health hazard of the 21st century, and GLOBOCAN predicts increasing cancer incidence in the coming decades. Though several conventional treatment modalities exist, most of them end up causing off-target and debilitating effects, and drug resistance acquisition. Advances in our understanding of tumor molecular biology offer alternative strategies for precise, robust, and potentially less toxic treatment paradigms for circumventing the disease at the cellular and molecular level. Several deregulated molecules associated with tumorigenesis have been developed as targets in RNA interference (RNAi) based cancer therapeutics. RNAi, a post-transcriptional gene regulation mechanism, has significantly gained attention because of its precise multi-targeted gene silencing. Although the RNAi approach is favorable, the direct administration of small oligonucleotides has not been fruitful because of their inherent lower half-lives and instability in the biological systems. Moreover, the lack of an appropriate delivery system to the primary site of the tumor that helps determine the potency of the drug and its reach, has limited the effective medical utilization of these bio-drugs. Nanotechnology, with its unique characteristics of enhanced permeation and better tumor-targeting efficiency, offers promising solutions owing to the various possibilities and amenability for modifications of the nanoparticles to augment cancer therapeutics. Nanoparticles could be made multimodal, by designing and synthesizing multiple desired functionalities, often resulting in unique and potentially applicable biological structures. A small number of Phase I clinical trials with systemically administered siRNA molecules conjugated with nanoparticles have been completed and the results are promising, indicating that, these new combinatorial therapies can successfully and safely be used to inhibit target genes in cancer patients to alleviate some of the disease burden. In this review, we highlight different types of nano-based delivery strategies for engineering Nano-RNAi-based bio drugs. Furthermore, we have highlighted the insights gained from current research that are entering the preclinical evaluation and information about initial clinical developments, shaping the future for next generation cancer therapeutics.

Circulating long noncoding RNAs as potential biomarkers for stomach cancer: a systematic review and meta-analysis

Background

Recent researches have suggested that long noncoding RNA (lncRNA) is involved in the tumorigenesis and development of stomach cancer (SC). This meta-analysis aimed to identify the diagnostic performance of circulating lncRNAs in SC.

Methods

All relevant studies were systematically searched through PubMed, Web of Science, Cochrane Library, and EMBASE databases. The diagnostic values of lncRNAs were mainly assessed by pooled sensitivity, specificity, and summary receiver operating characteristic area under the curve (SROC AUC). Meta-DiSc 1.4, Review Manager 5.3, and STATA 12.0 were used for statistical analysis. The protocol for this systematic review was registered on INPLASY (INPLASY202120079) and is available in full on the inplasy.com (10.37766/inplasy2021.2.0079).

Results

A total of 42 eligible studies were included in this meta-analysis. The pooled sensitivity, specificity, and SROC AUC were 0.78 (95%CI 0.75–0.81), 0.75 (95%CI 0.71–0.78), and 0.83 (95%CI 0.80–0.86), respectively, suggesting that the lncRNAs test had a high accuracy for the diagnosis of SC. Obvious heterogeneity might come from the type of lncRNA through subgroup and meta-regression analysis. Fagan diagram shows the clinical value of lncRNAs test in SC.

Conclusions

Abnormal expression of circulating lncRNAs exhibits a high efficacy for diagnosing SC, which is promising in clinical application.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-021-02194-6.

Long noncoding RNA CEBPA-DT promotes cisplatin chemo-resistance through CEBPA/BCL2 mediated apoptosis in oral squamous cellular cancer

Intrinsic or developing resistance to chemotherapy drugs including cisplatin (CDDP) remains the major limitation of cancer therapeutic efficacy in cancers. Recently, increasing evidence suggested that long noncoding RNAs (lncRNAs) play a critical role in various biological processes of tumors, and have been implicated in resistance to various drugs. However, the role of lncRNAs in cisplatin resistance is poorly understood. Here, we found that the expression of lncRNA CEBPA-DT/CEBPA/BCL2 was upregulated in cisplatin resistance OSCC cells (Cal27-CisR and HSC4-CisR) compared with their parental cells (Cal27 and HSC4). CEBPA-DT overexpression could upregulated both cytoplasmic and nuclear CEBPA expression. Down-regulation of CEBPA-DT enhances cisplatin sensitivity, facilitates cell apoptosis in cisplatin-resistant OSCC cells. In addition, we identified that CEBPA-DT regulates cisplatin chemosensitivity through CEBPA/BCL2-mediated cell apoptosis. Knockdown of CEBPA and BCL2 could alleviate the increasement of cisplatin resistance induced by CEBPA-DT overexpression. Our findings indicate that downregulation of lncRNA CEBPA-DT may be a potential therapy to overcome cisplatin resistance in OSCC.

lncRNA HOTAIR knockdown suppresses gastric cancer cell biological activities

The aim of this study was to characterize the involvement of long noncoding RNA HOTAIR in gastric cancer development. Measurement of HOTAIR and miRNA-206 expression by in situ hybridization (ISH) and analyzed for the correlation between HOTAIR and miRNA-206 in gastric cancer tissues. To evaluate the effects of HOTAIR in gastric cancer, MTT assay, flow cytometry, transwell, and wound healing assays were applied. To explain the mechanism behind HOTAIR's involvement, the expression of proteins related to it was also measured by Western blotting. Finally, correlations among related factors were determined by a luciferase target experiment. HOTAIR expression significantly increased, and miRNA-206 expression significantly decreased in cancer tissues (p < .01 and p < .001, respectively); HOTAIR knockdown suppressed cell viability, increased cell apoptosis by maintaining cells in the G1 phase, and inhibited cell invasion and migration by regulating miRNA-206 expression (p < .01 or p < .001). Meanwhile, with HOTAIR knockdown, CCND1 and CCND2 protein expressions were significantly suppressed, whereas miRNA-206 expression increased (p < .01 or p < .001). HOTAIR was shown to target miRNA-206 and miRNA-206 targeted CCND1 and CCND2. HOTAIR knockdown had antitumor effects by suppressing CCND1 and CCND2 expression by stimulating miRNA-206 in gastric cancer in vitro study.

Exosomes: A new horizon in modern medicine

Exosomes are a type of extracellular vesicles belonging to endocytic origin. These vesicles carry different biological cargo that play numerous physiological roles and is also indicative of different diseased state. Exosomes are considered as promising tools for therapeutic drug delivery, owing to their intrinsic features like stability, biocompatibility and a capacity of stealth. A clearer understanding of the composition, biogenesis and biology of exosomes can provide us with better insights into the pathophysiological, diagnostic, and therapeutic roles of these extracellular vesicles. In this review we have summarize existing literature regarding the production, efficacy, action mechanism, and potential therapeutic roles of exosomes in the contexts of various diseases such as cancer, renal disease, neurological disorders, cardio-vascular diseases, inflammatory diseases and some of the auto-immune diseases.

Diagnostic value of circulating lncRNAs as biomarkers of digestive system cancers: A systematic review and meta-analysis

OBJECTIVE

This meta-analysis aims to explore the diagnostic value and accuracy of circulating lncRNAs as biomarkers of digestive system tumors.

METHODS

PubMed, Embase, Cochrane Library, and Web of science were searched for relevant articles that were published before April 2019, and a meta-analysis was conducted.

RESULTS

52 studies with 63 lncRNAs were discussed in the meta-analysis. The pooled sensitivity and specificity of diagnosis were 0.80 (95% CI: 0.79-0.81) and 0.76 (95% CI: 0.75-0.77), respectively. The pooled DOR (the diagnostic odds ratio) was 15.63 (95% CI: 12.77-19.12), and the overall AUC (the area under the curve) was 0.87. Besides, subgroup analyzes showed that the DOR and AUC of large sample sizes (>80), multiple lncRNAs, serum-based lncRNAs, and downregulation group were superior to those of small sample sizes (≤80), single lncRNA, plasma-based lncRNAs, and upregulation group, respectively. The current data also highlight that the diagnostic accuracy of circulating lncRNAs in the case of colorectal cancer was higher than gastric cancer, hepatocellular carcinoma, esophageal carcinoma, and pancreatic cancer. And there is no difference in the perspective of geographical regions.

CONCLUSION

The circulating lncRNAs have high diagnostic value and accuracy in digestive system cancers and may serve as potential biomarkers.

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.

Fifteen mRNA-lncRNA expression-based signature predicted the survival of late-staged head and neck squamous cell carcinoma

Background: Gene expression is necessary for regulation in almost all biological processes, at the same time, it is related to the prognosis for head and neck squamous cell carcinoma (HNSCC). The prognosis of late-staged HNSCC is important because of its guiding significance on the therapy strategies.

Methods: In this work, we analyzed the relationship between gene expression and HNSCC in The Cancer Genome Atlas (TCGA) cohort, and optimized the panel with random forest survival analysis. Subsequently, a Cox multivariate regression-based model was developed to predict the clinical outcome of HNSCC. The performance of the model was assayed in the training cohort and validated in another three independent cohorts (GSE41614, E-TABM-302, E-MTAB-1328). The underlying pathways significantly associated with the model were identified. According to the results, patients of low-score group (median survival months: 27.4, 95% CI: 18.2–43) had a significant poor survival than those of high-score group (median survival months: 69.4, 95% CI: 58.7–72.1, P=2.7e-5), and the observation was repeatable in the other validation cohorts. Further analysis revealed that the model performed better than the other clinical indicators and is independent of these indicators.

Results: Comparison revealed that the model performed better than existing models for late HNSCC prognosis. Gene set enrichment analysis (GSEA) elucidated that the model was significantly associated with various cell processes and pathways.

DICER-AS1 lncRNA: A putative culprit in the pathogenesis of gastric cancer

The nuclear factor-κB (NF-κB) has a pivotal role in the pathogenesis of several cancers including gastric cancer. We have recently reported dysregulation of a number of NF-κB-associated lncRNAs in a variety of human disorders including breast cancer and coronary artery disease. In the current study, we evaluated expression of five NF-κB-associated lncRNAs (CHAST, ADINR, DICER1-AS1, HNF1A-AS1 and NKILA) and two NF-κB-associated-mRNA coding genes (CEBPA and ATG5) in gastric cancer tissues and their paired non-cancerous tissues using real time PCR method. Expression of DICER-AS1 was significantly down-regulated in gastric cancer tissues compared with the corresponding non-cancerous tissues (Expression ratio = 0.23, P value = .01). Expressions of other genes were not significantly different between these two sets of samples. Relative expression of DICER1-AS1 in cancer tissues versus non-cancerous tissues tended to associated with histological grade (P = .05). Tumoral expression levels of NKILA, ADINR, CEBPA and HNF1A-AS1 were significantly higher in patients with positive family history of cancer compared with those without such history (P values = .03, 0.02, 0.02 1nd 0.03, respectively). Besides, expression levels of NKILA, ADINR, DICER1-AS1, CEBPA, CHAST, HNF1A-AS1 and ATG5 were lower in H. pylori-infected tissues (P values = .01, 0.02, 0.03, 0.01, 0.004, 0.004 and 0.04, respectively). The lowest tumoral expression of DICER1-AS1 was detected in stage II cancers, while the highest expression of this lncRNA was reported in a single stage I tumor tissue. Similar pattern of expression was detected for ATG5. Significant pairwise correlations were demonstrated between expression levels of NF-ƙB-associated genes in both gastric cancer tissues and non-cancerous tissues. Expression levels of DICER1-AS1 had sensitivity and specificity values of 63.3% and 63.3% in differentiating between tumoral and non-tumoral tissues (Estimate criterion>6.96, J = 0.27, P value = .01, AUC = 0.67). Although previous studies have reported involvement of NF-κB pathway in the pathogenesis of gastric cancer, among the reported lncRNAs associated with this pathway, we could only detect differential expression of DICER1-AS1 between tumoral and non-tumoral tissues. Thus, the mechanism underlying dysregulation of this pathway might be different among various cancers.

LncRNA MIR4435-2HG potentiates the proliferation and invasion of glioblastoma cells via modulating miR-1224-5p/TGFBR2 axis

Glioblastoma (GBM) belongs to the high-grade (IV) gliomas with extremely poor prognosis. Accumulating evidence uncovered the key roles of long non-coding RNAs (lncRNAs) in GBM development. This study aimed to determine the biological actions and the clinical relevance of lncRNA MIR4435-2 Host Gene (MIR4435-2HG) in GBM. Data from GEPIA database showed that MIR4435-2HG was up-regulated in GBM tissues and high expression of MIR4435-2HG correlated with shorter overall survival of GBM patients. Further experimental assays verified the up-regulation of MIR4435-2HG in GBM tissues and cell lines. In vitro cell studies and in vivo animal studies showed that knockdown of MIR4435-2HG resulted in the inhibition of GBM cell proliferation and invasion and in vivo tumour growth, while MIR4435-2HG overexpression driven GBM progression. Furthermore, MIR44435-2HG was found to sponge miR-1224-5p and suppress miR-1224-5p expression; overexpression of miR-1224-5p attenuated the enhancement in GBM cell proliferation and invasion induced by MIR4435-2HG overexpression. In a subsequent study, miR-1224-5p was found to target transforming growth factor-beta receptor type 2 (TGFBR2) and repressed TGFBR2 expression, and in vitro assays showed that miR-1224-5p exerted tumour-suppressive effects via targeting TGFBR2. More importantly, TGFRB2 knockdown antagonized hyper-proliferation and invasion of GBM cells with MIR4435-2HG overexpression. Clinically, the down-regulation of miR-1224-5p and up-regulation of TGFBR2 were verified in the GBM clinical samples. Taken together, the present study suggests the oncogenic role of MIR4435-2HG in GBM and underlies the key function of MIR4435-2HG-driven GBM progression via targeting miR-1224-5p/TGFBR2 axis.

Long non-coding RNAs towards precision medicine in gastric cancer: early diagnosis, treatment, and drug resistance

Gastric cancer is a deadly disease and remains the third leading cause of cancer-related death worldwide. The 5-year overall survival rate of patients with early-stage localized gastric cancer is more than 60%, whereas that of patients with distant metastasis is less than 5%. Surgical resection is the best option for early-stage gastric cancer, while chemotherapy is mainly used in the middle and advanced stages of this disease, despite the frequently reported treatment failure due to chemotherapy resistance. Therefore, there is an unmet medical need for identifying new biomarkers for the early diagnosis and proper management of patients, to achieve the best response to treatment. Long non-coding RNAs (lncRNAs) in body fluids have attracted widespread attention as biomarkers for early screening, diagnosis, treatment, prognosis, and responses to drugs due to the high specificity and sensitivity. In the present review, we focus on the clinical potential of lncRNAs as biomarkers in liquid biopsies in the diagnosis and prognosis of gastric cancer. We also comprehensively discuss the roles of lncRNAs and their molecular mechanisms in gastric cancer chemoresistance as well as their potential as therapeutic targets for gastric cancer precision medicine.

LncRNA MIR4435-2HG-mediated upregulation of TGF-β1 promotes migration and proliferation of nonsmall cell lung cancer cells

The roles of long noncoding RNAs (lncRNAs) have been shown to play critical roles in tumor progression. Here, it was identified that lncRNA MIR4435-2HG was highly expressed in lung cancer tissues, especially in nonsmall cell lung cancer (NSCLC). A consistent result was obtained in lung cancer cells. Functional experiments showed that knockdown of MIR4435-2HG reduced the proliferation and migration ability of NSCLC cells. Transcriptome-sequencing analysis indicated that TGF-β signaling was mostly enriched in NSCLC cells with MIR4435-2HG knockdown. Furthermore, MIR4435-2HG was identified as an miRNA sponge for TGF-β1 and thus activated TGF-β signaling. Additionally, re-activation of TGF-β1 rescued MIR4435-2HG knockdown-mediated inhibition on the progression of NSCLC cells. Therefore, this work indicates a novel MIR4435-2HG/TGF-β1 axis responsible for NSCLC cell progression.

Transcriptome Analysis Identifies LINC00152 as a Biomarker of Early Relapse and Mortality in Acute Lymphoblastic Leukemia

Evidence showing the role of long non-coding RNAs (lncRNAs) in leukemogenesis have emerged in the last decade. It has been proposed that these genes can be used as diagnosis and/or prognosis biomarkers in childhood acute lymphoblastic leukemia (ALL). To know if lncRNAs are associated with early relapse and early mortality, a microarray-based gene expression analysis in children with B-lineage ALL (B-ALL) was conducted. Cox regression analyses were performed. Hazard ratios (HR) and 95% confidence intervals (95% CI) were calculated. LINC00152 and LINC01013 were among the most differentially expressed genes in patients with early relapse and early mortality. For LINC00152 high expression, the risks of relapse and death were HR: 4.16 (95% CI: 1.46–11.86) and HR: 1.99 (95% CI: 0.66–6.02), respectively; for LINC01013 low expression, the risks of relapse and death were HR: 3.03 (95% CI: 1.14–8.05) and HR: 6.87 (95% CI: 1.50–31.48), respectively. These results were adjusted by NCI risk criteria and chemotherapy regimen. The lncRNA–mRNA co-expression analysis showed that LINC00152 potentially regulates genes involved in cell substrate adhesion and peptidyl–tyrosine autophosphorylation biological processes. The results of the present study point out that LINC00152 could be a potential biomarker of relapse in children with B-ALL.

Long non-coding RNAs in genitourinary malignancies: a whole new world

Long non-coding RNAs (lncRNAs) are regulators of cellular machinery that are commonly dysregulated in genitourinary malignancies. Accordingly, the investigation of lncRNAs is improving our understanding of genitourinary cancers, from development to progression and dissemination. lncRNAs are involved in major oncogenic events in genitourinary malignancies, including androgen receptor (AR) signalling in prostate cancer, hypoxia-inducible factor (HIF) pathway activation in renal cell carcinoma and invasiveness in bladder cancer, as well as multiple other proliferation and survival mechanisms. In line with their putative oncogenic roles, new lncRNA-based classifications are emerging as potent predictors of prognosis. In clinical practice, detection of oncogenic lncRNAs in serum or urine might enable early cancer detection, and lncRNAs might also be promising therapeutic targets for patients with genitourinary cancer. Furthermore, as predictors of sensitivity to anticancer treatments, lncRNAs could be integrated into future precision medicine strategies. Overall, lncRNAs are promising new candidates for molecular studies and for discovery of innovative biomarkers and are putative therapeutic targets in genitourinary oncology.

Exosomal Long Non-Coding RNA CEBPA-AS1 Inhibits Tumor Apoptosis and Functions as a Non-Invasive Biomarker for Diagnosis of Gastric Cancer

AIM

Traditional non-invasive diagnostic markers for gastric cancer (GC) exhibit insufficient sensitivity and specificity. Circulating exosomes are clinically useful non-invasive biomarkers for tumor diagnosis. In addition to their potential role in cancer biology, circulating long non-coding RNAs (lncRNAs) are a new class of promising cancer biomarkers. In the present study, we aimed to identify lncRNAs in circulating exosomes with potential as biomarkers for GC detection.

METHODS

We compared the expression of CEBPA-AS1 between GC cells and gastric epithelial cells. The biological function of exosomal CEBPA-AS1 was determined by cell phenotype experiments and rescue assays. We also compared the expression of CEBPA-AS1 in cancerous tissue from GC patients and corresponding adjacent normal tissues, as well as the expression of CEBPA-AS1 in plasma exosomes of GC patients and healthy controls. Diagnostic accuracy was assessed by the receiver operating characteristic (ROC) curve and area under the curve (AUC).

RESULTS

CEBPA-AS1 was highly expressed in both GC cells and in exosomes secreted by GC cells. In addition, CEBPA-AS1-containing exosomes secreted by GC cells could promote cell proliferation and inhibit apoptosis, thereby inducing the malignant behavior of GC cells. The level of CEBPA-AS1 was also significantly increased in tissues and plasma exosomes of GC patients. Stability tests showed that most plasma CEBPA-AS1 was encased in exosomes, thus avoiding degradation by RNases. We evaluated the diagnostic accuracy of exosome-derived CEBPA-AS1. The AUC value of CEBPA-AS1 in discriminating GC patients from healthy controls was 0.824, which was higher than the diagnostic accuracy of other traditional tumor biomarkers.

CONCLUSION

CEBPA-AS1-containing exosomes secreted from GC cells could promote cell proliferation, inhibit apoptosis, and induce GC progression, indicating that exosomal CEBPA-AS1 is involved in cell-to-cell communication in GC carcinogenesis. Exosomal CEBPA-AS1 is a promising new biomarker for clinical diagnosis of GC.

Long non-coding RNA signature in gastric cancer

Gastric cancer as a common human malignancy has been associated with aberrant expressions of several coding and non-coding genes. Long non-coding RNAs (lncRNAs) as regulators of gene expressions at different genomic, transcriptomic and post-transcriptomic levels are among putative biomarkers and therapeutic targets in gastric cancer. In the present study, we have searched available literature and listed lncRNAs that are involved in the pathogenesis of gastric cancer. In addition, we discuss associations between expressions of these lncRNAs and tumoral features or risk factors for gastric cancer. Based on the established role of lncRNAs in regulation of genomic stability, cell cycle, apoptosis, angiogenesis and other aspects of cell physiology, the potential of these transcripts as therapeutic targets in gastric cancer should be evaluated in future studies.

Circulating lncRNA SNHG11 as a novel biomarker for early diagnosis and prognosis of colorectal cancer

Colorectal cancer (CRC) is the third most common cancer and the second leading cause of cancer mortality worldwide. Emerging evidence indicates that tumour cells release substantial amounts of RNA into the bloodstream, in which RNA strongly resists RNases and is present at sufficient levels for quantitative analyses. Our study aimed to discover blood-based markers for the early detection of CRC and to ascertain their efficiency in discriminating healthy controls, patients with polyps and adenomas and cancer patients. We first analysed and screened ZFAS1, SNHG11, LINC00909 and LINC00654 in a bioinformatics database and then collected clinical plasma samples for preliminary small-scale analysis and further large-scale verification. We then explored the mechanism of dominant lncRNA SNHG11 expression in CRC by in vitro and in vivo assays. The combination of ZFAS1, SNHG11, LINC00909 and LINC00654 showed high diagnostic performance for CRC (AUC: 0.937), especially early-stage disease (AUC: 0.935). Plasma levels of the four candidate lncRNAs were significantly reduced in postoperative samples compared to preoperative samples. A panel including these four lncRNAs performed well in distinguishing patient groups with different stages of colon disease, and SNHG11 exhibited the greatest diagnostic ability to identify precancerous lesions and early-stage tumour formation. Mechanistically, high SNHG11 expression promotes proliferation and metastasis by targeting the Hippo pathway. Taken together, the data indicate that SNHG11 may be a novel therapeutic target for the treatment of CRC and a potential biomarker for the early detection of CRC.

lncRNA CEBPA-AS1 Overexpression Inhibits Proliferation and Migration and Stimulates Apoptosis of OS Cells via Notch Signaling

Osteosarcoma (OS) is the most common primary bone malignancy derived from primitive bone-forming mesenchymal cells. Long noncoding RNA (lncRNA) expression profiles have been intensively studied for their involvement in OS. Herein, we clarify whether lncRNA CEBPA-AS1 is a regulator of NCOR2 in OS cells. Microarray-based expression analysis identified OS-related differentially expressed lncRNA and predicted microRNAs (miRs) binding to lncRNA and mRNA. lncRNA CEBPA-AS1 and NCOR2 were found to be weakly expressed in OS tissues and cells. Next, functional investigation revealed that lncRNAs CEBPA-AS1 bound to miR-10b-5p to upregulate NCOR2. Following that, gene-targeted knockdown and overexpressed recombinant vectors of lncRNA CEBPA-AS1 and NCOR2 were constructed to explore the effects of lncRNA CEBPA-AS1 and NCOR2 on cell proliferation, differentiation, migration, and apoptosis. Finally, tumor formation was measured in nude mice. lncRNA CEBPA-AS1 overexpression or NCOR2 elevation inhibited cell proliferation and migration, and alkaline phosphatase (ALP) and bone gla protein (BGP) activity, while enhancing apoptosis and tumor formation. Furthermore, NCOR2 was elevated in response to lncRNA CEBPA-AS1 overexpression, thus repressing the Notch signaling pathway. Taken together, lncRNA CEBPA-AS1 overexpression inhibits OS progression through diminishing activation of the Notch signaling pathway via upregulating NCOR2. Therefore, lncRNA CEBPA-AS1 may serve as a molecular target for treating OS.

UCA1 long non-coding RNA: An update on its roles in malignant behavior of cancers

The lncRNA urothelial carcinoma-associated 1 (UCA1) is a 1.4 kb long transcript which has been firstly recognized in human bladder cancer cell line. Subsequent studies revealed its over-expression in a wide array of human cancer cell lines and patients' samples. In addition to conferring malignant phenotype to cells, it enhances resistance to conventional anti-cancer drugs. Moreover, transcript levels of this lncRNA have been regarded as diagnostic markers in several cancer types including gastric, bladder and liver cancers. The underlying mechanism of its participation in carcinogenesis has been identified in some cancer types. Sponging tumor suppressor miRNAs, interacting with cancer-promoting signaling pathways and enhancing cell cycle progression are among these mechanisms. Although few studies have shown anti-carcinogenic properties for this lncRNA, the bulk of evidence supports its oncogenic roles. In the current study, we have reviewed the current literature on the role of UCA1 in the carcinogenic process based on the results of in vitro studies, investigations in animal models and assessment of UCA1 expression in clinical samples.

AK001058 promotes the proliferation and migration of colorectal cancer cells by regulating methylation of ADAMTS12

BACKGROUND

Long noncoding RNA (LncRNA) functions as multiple mechanisms, including DNA methylation in colorectal cancer (CRC). ADAMTS12 was applied as biomarkers in CRC via abnormally DNA methylation. Lnc-AK001058 gene, which was reported dysregulated in CRC, is located adjacent to the gene ADAMTS12. However, little is known about the role of AK001058 during the proliferation and migration of CRC.

MATERIAL AND METHODS

In present study, quantitative RT-PCR were used to measure AK001058 and ADAMTS12 expression levels, and western blotting assays were performed to measure ADAMTS12 expression in CRC cells. Methylation-specific PCR (MSP) was applied to measure the methylation of the CpG islands of the ADAMTS12 promoter. Cell proliferation, migration, invasion and cycle assays ware utilized to analyze the role of AK001058 in CRC.

RESULTS

The results indicated that the expression of AK001058 was significantly increased in CRC. Overexpression of AK001058 could suppress the expression of ADAMTS12. AK001058 also significantly promoted cell proliferation, migration and invasion, and prolonged S stage of CRC, while silencing the expression of AK001058 showed contrary effects. Moreover, compared with negative control and AK001058-NC groups, overexpression of AK001058 could increase the DNA methylation level of ADAMTS12 gene promoter in CRC, while si-AK001058 could reverse this effect.

CONCLUSION

In conclusion, AK001058 promotes the proliferation, invasion, migration, and prolonged S stage of CRC by regulating methylation of ADAMTS12. Our research will provide new insights for the biomarker of colorectal cancer diagnose and new clues for clinical treatment.

LncRNA MIR4435-2HG targets desmoplakin and promotes growth and metastasis of gastric cancer by activating Wnt/β-catenin signaling

Long non-coding RNAs (lncRNAs) have been implicated in the pathogenesis of gastric cancer; however, their mechanisms of action remain largely unknown. The aim of this study was to identify lncRNAs involved in the tumorigenesis of gastric cancer and to investigate the signaling pathways they affect. Using microarray and RT-qPCR analyses, candidate lncRNAs were screened in paired gastric cancer tissues. The analysis revealed MIR4435-2HG to be markedly up-regulated in gastric cancer samples compared to normal stomach specimens. Increased MIR4435-2HG expression was associated with aggressive clinicopathologic features and unfavorable tumor stage. Functional experiments showed that MIR4435-2HG up-regulation enhanced gastric cancer cell proliferation, clonogenicity, and migration and invasion in vitro, as well as tumorigenicity in mice. Using RNA pull-down and mass-spectrometry analyses we found and verified a direct and novel interaction between MIR4435-2HG and desmoplakin (DSP), the most abundant desmosomal protein. Overexpression and knockdown experiments revealed opposing roles for DSP and MIR4435-2HG, unmasking a cascade through which MIR4435-2HG binds to and inhibits DSP, leading to activation of WNT/β-catenin signaling and epithelial-mesenchymal transition in gastric cancer cells. We propose that the MIR4435-2HG/DSP/WNT axis serves as a critical effector of carcinogenesis and progression of gastric cancer, and could be exploited therapeutically to improve patients' outcomes.

LncRNA MIR4435-2HG is downregulated in osteoarthritis and regulates chondrocyte cell proliferation and apoptosis

Purpose

MIR4435-2HG is an oncogenic lncRNA in gastric cancer and lung cancer. Our preliminary microarray data showed that MIR4435-2HG was downregulated in osteoarthritis plasma specimen, indicating the possible involvement of MIR4435-2HG in osteoarthritis.

Results

MIR4435-2HG was downregulated in plasma of osteoarthritis than in plasma of healthy controls. Reduced levels of MIR4435-2HG expression effectively distinguished osteoarthritis patients from the control group. Expression levels of MIR4435-2HG increased after treatment. Overexpression of MIR4435-2HG promoted, while MIR4435-2HG knockdown inhibited the proliferation of chondrocytes. In contrast, MIR4435-2HG overexpression inhibited, while MIR4435-2HG knockdown promoted the apoptosis of chondrocytes.

Conclusion

MIR4435-2HG is downregulated in osteoarthritis and regulates chondrocyte cell proliferation and apoptosis.

Discovery of plasma messenger RNA as novel biomarker for gastric cancer identified through bioinformatics analysis and clinical validation

Background

Gastric cancer (GC) is the third leading cause of cancer-related death worldwide, partially due to the lack of effective screening strategies. Thus, there is a stringent need for non-invasive biomarkers to improve patient diagnostic efficiency in GC.

Methods

This study initially filtered messenger RNAs (mRNAs) as prospective biomarkers through bioinformatics analysis. Clinical validation was conducted using circulating mRNA in plasma from patients with GC. Relationships between expression levels of target genes and clinicopathological characteristics were calculated. Then, associations of these selected biomarkers with overall survival (OS) were analyzed using the Kaplan-Meier plotter online tool.

Results

Based on a comprehensive analysis of transcriptional expression profiles across 5 microarrays, top 3 over- and underexpressed mRNAs in GC were generated. Compared with normal controls, expression levels of collagen type VI alpha 3 chain (COL6A3), serpin family H member 1 (SERPINH1) and pleckstrin homology and RhoGEF domain containing G1 (PLEKHG1) were significantly upregulated in GC plasmas. Receiver-operating characteristic (ROC) curves on the diagnostic efficacy of plasma COL6A3, SERPINH1 and PLEKHG1 mRNAs in GC showed that the area under the ROC (AUC) was 0.720, 0.698 and 0.833, respectively. Combined, these three biomarkers showed an elevated AUC of 0.907. Interestingly, the higher COL6A3 level was significantly correlated with lymph node metastasis and poor prognosis in GC patients. High level of SERPINH1 mRNA expression was correlated with advanced age, poor differentiation, lower OS, and PLEKHG1 was also associated with poor OS in GC patients.

Conclusion

Our results suggested that circulating COL6A3, SERPINH1 and PLEKHG1 mRNAs could be putative noninvasive biomarkers for GC diagnosis and prognosis.

In silico identification of novel lncRNAs with a potential role in diagnosis of gastric cancer

Gastric cancer (GC) is the second leading cause of cancer-related deaths in the world. Due to the shortage of adequate symptoms in the early stages, it is diagnosed when the tumor has spread to distant organs. Early recognition of GC enhances the chance of successful treatment. Molecular mechanisms of GC are still poorly understood. LncRNAs are emerging as new players in cancer in both oncogene and tumor suppressor roles. High-throughput technologies such as RNA-Seq, have revealed thousands of lncRNAs which are dysregulated in GC. In this study, we retrieved lncRNAs obtained by High-throughput technologies from OncoLnc database. Consequently, retrieved lncRNAs were compared in literature-based databases including PubMed. As a result, two lists, including experimentally validated lncRNAs and predicted lncRNAs were provided. We found 43 predicted lncRNAs that had not been experimentally validated in GC, so far. Further Bioinformatics analyses were performed to obtain the expression profile of predicted lncRNAs in tumor and normal tissues. Also, the roles and targets of predicted lncRNAs in GC were identified by related databases. Finally, using the GEPIA database was reviewed the significant relationship of predicted lncRNAs with the survival of GC patients. By recognizing the lncRNAs involved in initiation and progression of GC, they may be considered as potential biomarkers in the GC early diagnosis or targeted treatment and lead to novel therapeutic strategies. Communicated by Ramaswamy H. Sarma.

LncRNA MIR4435-2HG predicts poor prognosis in patients with colorectal cancer

Background

LncRNA MIR4435-2HG is observed in a variety of cancers, while its role in colorectal cancer is unknown. We aimed to demonstrate the relationship between MIR4435-2HG and colorectal cancer based on The Cancer Genome Atlas (TCGA) database.

Materials and Methods

Patients with colorectal cancer were collected from TCGA. We compared the expression of MIR4435-2HG in colorectal cancer and normal tissues with Wilcoxon rank sum test, and logistic regression was used to evaluate the relationship between MIR4435-2HG and clinicopathological characters. Moreover, Kaplan–Meier and Cox regression was performed to evaluate the correlation between MIR4435-2HG and survival rate. Gene set enrichment analysis (GSEA) was also conducted to annotate biological function of MIR4435-2HG.

Results

MIR4435-2HG level was elevated in colorectal cancer tissues. Increased level of MIR4435-2HG was significantly correlated with TNM stage (OR = 1.66 for T1/T2 vs. T3/T4; OR = 1.68 for N0 vs. N1/N2), stage (OR = 1.66 for stage 1/2 vs. stage 3/4), and carcinoembryonic antigen level before treatment (OR = 1.70 for <5 vs. ≥5) (all P-value <0.05). High MIR4435-2HG expression had a poorer progression-free survival (p = 0.048), and overall survival (OS) (P = 0.028), which were validated in the GSE92921 and GSE29621 datasets. MIR4435-2HG expression (P = 0.040, HR = 1.955 (95% CI [1.031–3.710])) was independently correlated with OS. GSEA demonstrated that the P38/MAPK pathway, the VEGF pathway, the cell adhesion molecules cams, the NOD-like receptor signaling pathway, the cell surface interactions at the vascular wall, and integrin cell surface interactions were differentially enriched in MIR4435-2HG high expression phenotype.

Conclusions

Increased MIR4435-2HG might be a potential biomarker for the diagnosis and prognosis of colorectal cancer. Moreover, MIR4435-2HG might participate in the development of colorectal cancer via the P38/MAPK and VEGF pathway.

LncRNA ENST00000539653 acts as an oncogenic factor via MAPK signalling in papillary thyroid cancer

Background

Papillary thyroid cancer (PTC) is the most frequent type of thyroid malignancy. In this study, we investigated the mechanisms whereby long non-coding RNAs (lncRNAs) are associated with PTC pathogenesis.

Methods

Microarray analysis was used to determine differentially expressed lncRNAs between paired PTC tissues and normal adjacent thyroid tissues. Quantitative RT-PCR was used for validation in 86 PTC cases. Small interfering RNA (siRNA) transfection assays were then performed to assess how a novel lncRNA affected key proliferation and cell death pathways in IHH4 PTC cells.

Results

We identified 1878 differentially expressed lncRNAs versus matched control samples (fold change ≥2.0, P < 0.05), of which 429 were upregulated and 1449 were downregulated. ENST00000539653.1 (ENS-653), one of the top hits in this microarray, was selected for further study. Higher ENS-653 expression was observed in PTC tissue samples versus adjacent normal tissues, and was associated with a larger tumor size and a more advanced clinical stage. In the Cancer Genome Atlas (TCGA) PTC cohort, higher ENS-653 expression was correlated with more frequent BRAF (V600E) mutation and poorer disease-free survival. Furthermore, ENS-653 downregulation reduced the proliferation of PTC cells and led to G1-S arrest, but had no impact on apoptosis. ENS-653 downregulation also inactivated ERK1/2 and ERK5, causing partial MAPK cascade suppression.

Conclusion

ENS-653 exhibits oncogenic properties in PTC, and could be a diagnostic and/or prognostic PTC biomarker, in addition to possibly being a future target for therapy.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5533-4) contains supplementary material, which is available to authorized users.

A Panel of 12-lncRNA Signature Predicts Survival of Pancreatic Adenocarcinoma

Background: Recent studies have highlighted the important roles of long non-coding RNAs (lncRNAs) in pancreatic adenocarcinoma (PCa) prognosis. However, most studies explored a limited number of lncRNAs based on small sample size.

Methods: Systematic and comprehensive analysis of the data from The Cancer Genome Atlas (TCGA) was performed to identify a panel of lncRNA signature for predicting prognosis in PCa.

Results: A total of 160 PCa patients with complete clinical data were included in our study. Twelve lncRNAs were identified to be significantly associated with overall survival (OS) in PCa patients using Cox regression analysis. A risk score formula was constructed to assess the prognostic value of the lncRNA signature in PCa. Patients with high risk score had worse OS than those with low risk score. The multivariate Cox regression analyses revealed that the lncRNA signature was an independent prognostic factor. Additionally, the signature might act as an indicator to predict treatment outcome. Functional enrichment analyses showed that the lncRNAs might involve in several molecular pathways closely related with PCa such as DNA replication, pancreatic cancer and regulation of tor signaling.

Conclusions: Our study demonstrated a lncRNA signature including 12 lncRNAs with the potential to be served as an independent prognostic biomarker of PCa.

Investigation of CEBPA and CEBPA-AS Genes Expression in Acute Myeloid Leukemia

BACKGROUND

The pathogenicity of acute myeloid leukemia (AML) is highly influenced by genetic alterations, such as chromosomal abnormalities. Additionally, aberrations in the mechanisms involved in gene expression have been identified to have a role in the development of AML. Contradictory evidence has been reported concerning the expression of the CEBPA gene in AML patients. Additionally, investigation into the expression of the CEBPA-AS gene has yet to be explored in AML patients. The aim of the present study was to investigate the relationship between the expression of the CEBPA and CEBPA-AS genes and AML in Iranian patients.

METHODS

Using quantitative real-time PCR, the expression of the CEBPA and CEBPA-AS genes was examined in the peripheral blood samples of 58 patients with de novo adult AML, and in 20 healthy controls.

RESULTS

Overall, CEBPA expression analysis showed a significant up-regulation in AML patients compared with healthy controls. Interestingly, a significant up-regulation of CEBPA was detected in the male AML patients. Significant CEBPA over-expression was observed in M0 (p-value=0.0001), M3 (p-value= 0.012) and M4 (p-value= 0.000) FAB subtypes. Our data has also demonstrated that CEBPA expression is up-regulated in favorable (p-value= 0.006) and adverse (p-value= 0.042) cytogenetic risk groups. In addition, the expression of CEBPA was significantly increased in AML patients with an abnormal karyotype. Ectopic expression of CEBPA-AS was detected in seven of the AML patients.

CONCLUSION

Our study provides evidence for the up-regulation of CEBPA and the ectopic expression of CEBPA-AS in AML patients, suggesting that these two genes may play an important role in the pathogenesis of AML. The role of CEBPA and CEBPA-AS in AML patients should be further explored. This will offer potential opportunities for the development of novel treatment strategies.