Molecular mechanisms of long noncoding RNAs on gastric cancer. Oncotarget. 2016;7:8601-8612. [PMID: 26788991 PMCID: PMC4890990 DOI: 10.18632/oncotarget.6926]

Molecular and Therapeutic Roles of Non-Coding RNAs in Oral Cancer-A Review

Oral cancer (OC) is among the most common malignancies in the world. Despite advances in therapy, the worst-case scenario for OC remains metastasis, with a 50% survival rate. Therefore, it is critical to comprehend the pathophysiology of the condition and to create diagnostic and treatment plans for OC. The development of high-throughput genome sequencing has revealed that over 90% of the human genome encodes non-coding transcripts, or transcripts that do not code for any proteins. This paper describes the function of these different kinds of non-coding RNAs (ncRNAs) in OC as well as their intriguing therapeutic potential. The onset and development of OC, as well as treatment resistance, are linked to dysregulated ncRNA expression. These ncRNAs' potentially significant roles in diagnosis and prognosis have been suggested by their differing expression in blood or saliva. We have outlined every promising feature of ncRNAs in the treatment of OC in this study.

MALAT1 as a potential salivary biomarker in oral squamous cell carcinoma through targeting miRNA-124

OBJECTIVES

To determine the diagnostic accuracy of the long non-coding RNA "MALAT1" measured in the saliva of patients with oral squamous cell carcinoma (OSCC) and assess the salivary expression of microRNA-124, which MALAT1 targets.

SUBJECTS AND METHODS

Forty subjects were collected in a consecutive pattern and allocated into two groups. Group A included 20 patients with OSCC, while Group B included 20 healthy subjects. Salivary expression of MALAT1 and microRNA (miRNA)-124 was evaluated in the two study groups using quantitative real-time polymerase chain reaction and correlated with histopathological examination of OSCC subjects.

RESULTS

OSCC yielded a statistically significant higher expression of MALAT1 than healthy controls and a lower expression of miRNA-124 in OSCC than controls. There is a statistically significant inverse relationship between salivary MALAT1 and miRNA-124. Moreover, there is a statistically significant difference in the MALAT1 expression in saliva samples from metastatic cases compared with non-metastatic cases, as well as in patients with lymph node involvement compared with those without involvement. At a cut-off value of 2.24, salivary MALAT1 exhibited 95% sensitivity and 90% specificity in differentiating OSCC from healthy subjects.

CONCLUSION

Salivary MALAT1 acts as a sponge for miRNA-124 and could be a potential salivary biomarker for OSCC.

The prognostic, diagnostic, and therapeutic impact of Long noncoding RNAs in gastric cancer

Gastric cancer (GC), ranking as the third deadliest cancer globally, faces challenges of late diagnosis and limited treatment efficacy. Long non-coding RNAs (lncRNAs) emerge as valuable treasured targets for cancer prognosis, diagnosis, and therapy, given their high specificity, convenient non-invasive detection in body fluids, and crucial roles in diverse physiological and pathological processes. Research indicates the significant involvement of lncRNAs in various aspects of GC pathogenesis, including initiation, metastasis, and recurrence, underscoring their potential as novel diagnostic and prognostic biomarkers, as well as therapeutic targets for GC. Despite existing challenges in the clinical application of lncRNAs in GC, the evolving landscape of lncRNA molecular biology holds promise for advancing the survival and treatment outcomes of gastric cancer patients. This review provides insights into recent studies on lncRNAs in gastric cancer, elucidating their molecular mechanisms and exploring the potential clinical applications in GC.

Competing endogenous RNAs in head and neck squamous cell carcinoma: a review

Our understanding of RNA biology has evolved with recent advances in research from it being a non-functional product to molecules of the genome with specific regulatory functions. Competitive endogenous RNA (ceRNA), which has gained prominence over time as an essential part of post-transcriptional regulatory mechanism, is one such example. The ceRNA biology hypothesis states that coding RNA and non-coding RNA co-regulate each other using microRNA (miRNA) response elements. The ceRNA components include long non-coding RNAs, pseudogene and circular RNAs that exert their effect by interacting with miRNA and regulate the expression level of its target genes. Emerging evidence has revealed that the dysregulation of the ceRNA network is attributed to the pathogenesis of various cancers, including the head and neck squamous cell carcinoma (HNSCC). This is the most prevalent cancer developed from the mucosal epithelium in the lip, oral cavity, larynx and pharynx. Although many efforts have been made to comprehend the cause and subsequent treatment of HNSCC, the morbidity and mortality rate remains high. Hence, there is an urgent need to understand the holistic progression of HNSCC, mediated by ceRNA, that can have immense relevance in identifying novel biomarkers with a defined therapeutic intervention. In this review, we have made an effort to highlight the ceRNA biology hypothesis with a focus on its involvement in the progression of HNSCC. For the identification of such ceRNAs, we have additionally highlighted a number of databases and tools.

The recent advancements in circRNA research: From biogenesis to therapeutic interventions

Circular RNAs (circRNAs) belong to the genre of long non-coding RNAs that are formed by special back-splicing events and are currently the molecule of interest for studies globally due their involvement in various ailments like diabetes, neurodegenerative disorders, cardio-vascular diseases and cancers. These class of highly stable RNAs participate in diverse cellular functionalities including microRNA (miRNA) sponging, ceRNA (competing endogenous RNA) activity or via exhibiting RNA binding protein (RBP) interactions. They are also known to regulate cancer progression both positively and negatively through various biological pathways such as, modulating the cell cycle and apoptotic pathways, epigenetic regulation, and translational and/or transcriptional regulations etc. Given its significance, a variety of computational tools and dedicated databases have been created for the identification, quantification, and differential expression of such RNAs in combination with sequencing approaches. In this review, we provide a comprehensive analysis of the numerous computational tools, pipelines, and online resources developed in recent years for the detection and annotation of circRNAs. We also summarise the most recent findings regarding the characteristics, functions, biological processes, and involvement of circRNAs in diseases. The review emphasises the significance of circRNAs as potential disease biomarkers and new treatment targets.

Long Non-Coding RNA ZSCAN16-AS1 Promotes the Malignant Progression of Melanoma Through Regulating the miR-503-5p/ARL2 Axis

Background

LncRNA zinc finger and SCAN domain containing 16 antisense RNA 1 (ZSCAN16-AS1), a newly identified lncRNA, has been proven to accelerate hepatocellular carcinoma progression. However, the function and molecular mechanism of ZSCAN16-AS1 in melanoma are still unknown.

Methods

The level of ZSCAN16-AS1 in melanoma tissues was detected and reported in The Cancer Genome Atlas (TCGA) and GEO#GSE15605. CCK-8, Transwell and flow cytometry assays were used to explore the role of ZSCAN16-AS1 in melanoma cells. Luciferase reporter assays and RNA pull-down assays were used to verify the molecular mechanism of ZSCAN16-AS1.

Results

Here, we found that ZSCAN16-AS1 expression was increased in melanoma. We confirmed that ZSCAN16-AS1 promotes the growth and metastasis of melanoma. ZSCAN16-AS1 exerts its pro-tumour role through sponging of miR-503-5p to liberate ADP-ribosylation factor-like protein 2 (ARL2) mRNA transcripts.

Conclusion

These results demonstrated the role and molecular mechanism of ZSCAN16-AS1 in the occurrence and development of melanoma. Therefore, ZSCAN16-AS1 may be used as a specific biomarker in the diagnosis and treatment of melanoma patients.

Analysis and application of RNA binding protein gene pairs to predict the prognosis of gastric cancer

Background

RNA-binding proteins (RBPs) are closely related to tumors, but little is known about the mechanism of RBPs in tumorigenesis and progression of gastric cancer (GC). As genes do not usually act alone in the pathway deregulation, gene pair combinations are more likely to become stable and accurate biomarkers. The purpose of our research is to establish a novel signature based on RBP gene pairs to predict the prognosis of gastric cancer patients.

Methods

We downloaded genetic and clinical information from the TCGA and GEO database. TCGA and GSE13911 were used for screening differentially expressed genes (DEGs). The RBP genes were gathered from previous studies and employed to screen out DE-RBP genes after intersecting with DEGs. Samples were classified according to the relative expression of each pair of DE-RBP genes. The univariate Cox regression analysis and random forest were used to identify hub gene pairs to construct signature for predicting the prognosis of gastric cancer. Time-dependent ROC curves and KM survival curves were performed to evaluate the signature. GSEA was performed in TCGA training cohort and GSE62254 testing cohort to analyze enrichment pathways. Finally, the influence of these gene pairs on the prognosis of GC patients was further elucidated respectively through the combination of high and low expression of the two genes in each hub gene pair.

Results

We screened out 6 hub RBP gene pairs (COL5A2/FEN1, POP1/GFRA1, EXO1/PLEKHS1, SLC39A10/CHI3L1, MMP7/PPP1R1 B and SLC5A6/BYSL) to predict the prognosis of patients with gastric cancer. Using the optimal cut-off value to divide patients into high-risk and low-risk groups in the training and testing cohort, we found that the overall survival (OS) of the low-risk group was higher than that of the high-risk group (P < 0.05). The area under the ROC curves for 1, 3, and 5 years were (0.659, 0.744, 0.758) and (0.624, 0.650, 0.653) in two cohorts. Univariate and multivariate Cox regression analysis showed that 6 RBP gene pairs signature were independent prognostic factors for gastric cancer (P < 0.05). In addition, the prognostic survival analysis showed that COL5A2-high/FEN1-low, POP1-low/GFRA1-high, EXO1-low/PLEKHS1-low,SLC39A10-high/CHI3L1-low, MMP7-high/PPP1R1 B-low, SLC5A6-low/BYSL-low had worse OS (P < 0.05). And the gene correlation analysis showed that there was no obvious correlation between the genes in each gene pairs except SLC5A6/BYSL and POP1/GFRA1. Finally, GSEA analysis showed that the high-risk group was enriched in tumor migration, invasion and growth-related pathways.

Conclusion

Our study identified a novel 6 RBP gene pairs signature to predict the prognosis of gastric cancer patients and provide potential targets for clinical gene therapy.

Long noncoding RNA (lncRNA) H19: An essential developmental regulator with expanding roles in cancer, stem cell differentiation, and metabolic diseases

Recent advances in deep sequencing technologies have revealed that, while less than 2% of the human genome is transcribed into mRNA for protein synthesis, over 80% of the genome is transcribed, leading to the production of large amounts of noncoding RNAs (ncRNAs). It has been shown that ncRNAs, especially long non-coding RNAs (lncRNAs), may play crucial regulatory roles in gene expression. As one of the first isolated and reported lncRNAs, H19 has gained much attention due to its essential roles in regulating many physiological and/or pathological processes including embryogenesis, development, tumorigenesis, osteogenesis, and metabolism. Mechanistically, H19 mediates diverse regulatory functions by serving as competing endogenous RNAs (CeRNAs), Igf2/H19 imprinted tandem gene, modular scaffold, cooperating with H19 antisense, and acting directly with other mRNAs or lncRNAs. Here, we summarized the current understanding of H19 in embryogenesis and development, cancer development and progression, mesenchymal stem cell lineage-specific differentiation, and metabolic diseases. We discussed the potential regulatory mechanisms underlying H19's functions in those processes although more in-depth studies are warranted to delineate the exact molecular, cellular, epigenetic, and genomic regulatory mechanisms underlying the physiological and pathological roles of H19. Ultimately, these lines of investigation may lead to the development of novel therapeutics for human diseases by exploiting H19 functions.

LncRNA HOTAIR as a ceRNA is related to breast cancer risk and prognosis

PURPOSE

Breast cancer (BC) is one of the biggest threats to women's health. LncRNA HOTAIR is related to the recurrence and metastasis of BC. Whether HOTAIR can serve as an effective biomarker to distinguish BC patients with different prognosis need to be further studied.

METHODS

The miRNA and mRNA expression profile data of BC patients were downloaded from TCGA database. Univariate Cox regression was used to screen differential expression genes (DEGs). The miRcode database and miRWalk database were used to predict miRNA binding to HOTAIR and binding sites of miRNAs, respectively. Kaplan-Meier (KM) analysis was used to estimate the overall survival rate of BC patients. Finally, qRT-PCR and western blot were applied to evaluate the expression level of HOTAIR and mRNAs between BC cells and normal mammary cells.

RESULTS

The patients with high HOTAIR expression had poor prognosis in BC. Totally 10 genes correlated with BC prognosis were identified from 170 DEGs, among which PAX7, IYD, ZIC2, MS4A1, TPRXL, CD24, LHX1 were positively correlated with HOTAIR, while CHAD, NPY1R, TPRG1 were opposite. The levels of IYD, ZIC2, CD24 mRNA and protein were increased in BC tissues and BC cells. In BC cells, the levels of IYD, ZIC2 and CD24 mRNA and protein were significantly increased in HOTAIR overexpressed group. HOTAIR had the strongest interaction with hsa-miR-129-5p, followed by hsa-miR-107.

CONCLUSION

HOTAIR regulated the expression of downstream genes by interacting with 8 miRNAs and ultimately affected the prognosis of BC patients.

MicroRNA Regulation in Infectious Diseases and Its Potential as a Biosensor in Future Aquaculture Industry: A Review

An infectious disease is the most apprehensive problem in aquaculture as it can lead to high mortality in aquatic organisms and massive economic loss. Even though significant progress has been accomplished in therapeutic, prevention, and diagnostic using several potential technologies, more robust inventions and breakthroughs should be achieved to control the spread of infectious diseases. MicroRNA (miRNA) is an endogenous small non-coding RNA that post-transcriptionally regulates the protein-coding genes. It involves various biological regulatory mechanisms in organisms such as cell differentiation, proliferation, immune responses, development, apoptosis, and others. Furthermore, an miRNA also acts as a mediator to either regulate host responses or enhance the replication of diseases during infection. Therefore, the emergence of miRNAs could be potential candidates for the establishment of diagnostic tools for numerous infectious diseases. Interestingly, studies have revealed that miRNAs can be used as biomarkers and biosensors to detect diseases, and can also be used to design vaccines to attenuate pathogens. This review provides an overview of miRNA biogenesis and specifically focuses on its regulation during infection in aquatic organisms, especially on the host immune responses and how miRNAs enhance the replication of pathogens in the organism. In addition to that, we explored the potential applications, including diagnostic methods and treatments, that can be employed in the aquaculture industry.

Long non‑coding RNA LINC00460 contributes as a potential prognostic biomarker through its oncogenic role with ANXA2 in colorectal polyps

BACKGROUND

Long intergenic non-coding RNA 460 (LINC00460) as a potential oncogene and Annexin A2 (ANXA2) as a promoter in different cancer progression processes was considered. A significant relationship between the LINC00460 and ANXA2 has been recently discovered in colorectal cancer (CRC). Therefore, defining molecular biomarkers accompanied by lesion histopathologic features can be a suggestive prognostic biomarker in precancerous polyps. This study aimed to investigate the elusive expression pattern of ANXA2 and LINC00460 in polyps.

MATERIALS AND METHODS

The construction of the co-expression and correlation network of LINC00460 and ANXA2 was plotted. LINC00460 and ANXA2 expression in 40 colon polyps was quantified by reverse transcription-real-time polymerase chain reaction. The receiver operating characteristic (ROC) curve was designed for distinguishing the high-risk precancerous lesion from the low-risk. Further, bioinformatics analysis was applied to find the shared MicroRNA-Interaction-Targets (MITs) between ANXA2 and LINC00460, and the associated pathways.

RESULTS

ANXA2 has a high co-expression rank with LINC00460 in the lncHUB database. Overexpression of ANXA2 and LINC00460 was distinguished in advanced adenoma polyps compared to the adjacent normal samples. The estimated AUC for ANXA2 and LINC00460 was 0.88 - 0.85 with 93%-90% sensitivity and 81%-70% specificity. In addition, eight MITs were shared between ANXA2 and LINC00460. Enrichment analysis detected several GO terms and pathways, including HIF-1α associated with cancer development.

CONCLUSION

In conclusion, the expression of the ANXA2 and LINC00460 were significantly elevated in pre-cancerous polyps, especially in high-risk adenomas. Collectively, ANXA2 and LINC00460 may be administered as potential prognostic biomarkers in patients with a precancerous large intestine lesion as an alarming issue.

The TINCR ubiquitin-like microprotein is a tumor suppressor in squamous cell carcinoma

The TINCR (Terminal differentiation-Induced Non-Coding RNA) gene is selectively expressed in epithelium tissues and is involved in the control of human epidermal differentiation and wound healing. Despite its initial report as a long non-coding RNA, the TINCR locus codes for a highly conserved ubiquitin-like microprotein associated with keratinocyte differentiation. Here we report the identification of TINCR as a tumor suppressor in squamous cell carcinoma (SCC). TINCR is upregulated by UV-induced DNA damage in a TP53-dependent manner in human keratinocytes. Decreased TINCR protein expression is prevalently found in skin and head and neck squamous cell tumors and TINCR expression suppresses the growth of SCC cells in vitro and in vivo. Consistently, Tincr knockout mice show accelerated tumor development following UVB skin carcinogenesis and increased penetrance of invasive SCCs. Finally, genetic analyses identify loss-of-function mutations and deletions encompassing the TINCR gene in SCC clinical samples supporting a tumor suppressor role in human cancer. Altogether, these results demonstrate a role for TINCR as protein coding tumor suppressor gene recurrently lost in squamous cell carcinomas.

Chromatin and noncoding RNA-mediated mechanisms of gastric tumorigenesis

Gastric cancer (GC) is one of the most common and deadly cancers in the world. It is a multifactorial disease highly influenced by environmental factors, which include radiation, smoking, diet, and infectious pathogens. Accumulating evidence suggests that epigenetic regulators are frequently altered in GC, playing critical roles in gastric tumorigenesis. Epigenetic regulation involves DNA methylation, histone modification, and noncoding RNAs. While it is known that environmental factors cause widespread alterations in DNA methylation, promoting carcinogenesis, the chromatin- and noncoding RNA-mediated mechanisms of gastric tumorigenesis are still poorly understood. In this review, we focus on discussing recent discoveries addressing the roles of histone modifiers and noncoding RNAs and the mechanisms of their interactions in gastric tumorigenesis. A better understanding of epigenetic regulation would likely facilitate the development of novel therapeutic approaches targeting specific epigenetic regulators in GC.

The potential regulatory role of the lncRNA-miRNA-mRNA axis in teleost fish

Research over the past two decades has confirmed that noncoding RNAs (ncRNAs), which are abundant in cells from yeast to vertebrates, are no longer "junk" transcripts but functional regulators that can mediate various cellular and physiological processes. The dysregulation of ncRNAs is closely related to the imbalance of cellular homeostasis and the occurrence and development of various diseases. In mammals, ncRNAs, such as long noncoding RNAs (lncRNAs) and microRNAs (miRNAs), have been shown to serve as biomarkers and intervention targets in growth, development, immunity, and disease progression. The regulatory functions of lncRNAs on gene expression are usually mediated by crosstalk with miRNAs. The most predominant mode of lncRNA-miRNA crosstalk is the lncRNA-miRNA-mRNA axis, in which lncRNAs act as competing endogenous RNAs (ceRNAs). Compared to mammals, little attention has been given to the role and mechanism of the lncRNA-miRNA-mRNA axis in teleost species. In this review, we provide current knowledge about the teleost lncRNA-miRNA-mRNA axis, focusing on its physiological and pathological regulation in growth and development, reproduction, skeletal muscle, immunity to bacterial and viral infections, and other stress-related immune responses. Herein, we also explored the potential application of the lncRNA-miRNA-mRNA axis in the aquaculture industry. These findings contribute to an enhanced understanding of ncRNA and ncRNA-ncRNA crosstalk in fish biology to improve aquaculture productivity, fish health and quality.

Long non-coding RNAs as potential biomarkers or therapeutic targets in gastric cancer

Aim

This study aimed to find lncRNAs and mRNAs that were expressed differently by combining microarray datasets from different studies. This was done to find important target genes in gastric cancer for anti-cancer therapy.

Background

Gastric cancer (GC) is the fourth most frequent and second-most deadly malignancy worldwide. Thus, genetic diagnosis and treatment should focus on genetic and epigenetic variables. Based on several studies, disordered expression of non-coding RNAs (ncRNAs), such as lncRNAs, regulate gastric cancer invasion and metastasis. Besides, lncRNAs cooperatively regulate gene expression and GC progression.

Methods

We obtained differentially expressed mRNAs (DEmRNAs) and lncRNAs (DElncRNAs) from three GC tissue microarray datasets by meta-analysis and screened genes using the "Limma" package. Then, using the RNAInter database, we allocated DEmRNAs to each DElncRNA. ClusterProfiler and GOplot programs were used to analyze function enrichment pathways and gene ontologies for final DEmRNAs.

Results

A total of 9 differentially expressed lncRNAs (DElncRNAs) (5 up-regulated and 4 down-regulated), and 856 DEmRNAs (451 up-regulated and 405 down-regulated) between tumor and adjacent normal samples were found. Finally, 117 differentially expressed mRNAs were predicted as interactors of six DElncRNAs (H19, WT1-AS, EMX2OS, HOTAIR, ZEB1-AS1, and LINC00261).

Conclusion

In order to promote cancer therapeutics and give knowledge on the process of carcinogenesis, our study projected a network of drug-gene interactions for discovered genes and presented relevant prospective biomarkers for the prognosis of patients with stomach cancer.

Investigations into the impact of non-coding RNA on the sensitivity of gastric cancer to radiotherapy

Non-coding RNAs (ncRNAs) are a newly discovered functional RNA different from messenger RNA, which can participate in regulating the occurrence and development of tumors. More and more research results show that ncRNAs can participate in the regulation of gastric cancer (GC) radiotherapy response, and its mechanism may be related to its effect on DNA damage repair, gastric cancer cell stemness, cell apoptosis, activation of epidermal growth factor receptor signaling pathway, etc. This article summarizes the relevant mechanisms of ncRNAs regulating the response to radiotherapy in gastric cancer, which will be directly important for the introduction of ncRNAs particularly microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) into clinical medicine as biomarkers and therapeutic targets.

A prognostic signature of pyroptosis-related lncRNAs verified in gastric cancer samples to predict the immunotherapy and chemotherapy drug sensitivity

Background: Pyroptosis is a recently identified mode of programmed inflammatory cell death that has remarkable implications for cancer development. lncRNAs can be involved in cellular regulation through various pathways and play a critical role in gastric cancer (GC). However, pyroptosis -related lncRNAs (PRlncRNAs) have been rarely studied in GC.

Methods: Pyroptosis-related gene were abstracted from the literature and GSEA Molecular Signatures data resource. PRlncRNAs were obtained using co-expression analysis. LASSO Cox regression assessment was employed to build a risk model. Kaplan-Meier (KM), univariate along with multivariate Cox regression analysis were adopted to verify the predictive efficiency of the risk model in terms of prognosis. qRT-PCR was adopted to validate the expression of PRlncRNAs in GC tissues. In addition, immune cell infiltration assessment and ESTIMATE score evaluation were adopted for assessing the relationship of the risk model with the tumor immune microenvironment (TME). Finally, immune checkpoint gene association analysis and chemotherapy drug sensitivity analysis were implemented to assess the worthiness of our risk model in immunotherapy and chemotherapy of GC.

Results: We identified 3 key PRlncRNAs (PVT1, CYMP-AS1 and AC017076.1) and testified the difference of their expression levels in GC tumor tissues and neighboring non-malignant tissues (p < 0.05). PRlncRNAs risk model was able to successfully estimate the prognosis of GC patients, and lower rate of survival was seen in the high-GC risk group relative to the low-GC risk group (p < 0.001). Other digestive system tumors such as pancreatic cancer further validated our risk model. There was a dramatic difference in TMB level between high-GC and low-GC risk groups (p < 0.001). Immune cell infiltration analysis and ESTIMATE score evaluation demonstrated that the risk model can be adopted as an indicator of TME status. Besides, the expressions of immunodetection site genes in different risk groups were remarkably different (CTLA-4 (r = −0.14, p = 0.010), VISTA (r = 0.15, p = 0.005), and B7-H3 (r = 0.14, p = 0.009)). PRlncRNAs risk model was able to effectively establish a connection with the sensitivity of chemotherapeutic agents.

Conclusion: The 3 PRlncRNAs identified in this study could be utilized to predict disease outcome in GC patients. It may also be a potential therapeutic target in GC therapy, including immunotherapy and chemotherapy.

Integrated Analysis and Identification of Critical RNA-Binding Proteins in Bladder Cancer

Simple Summary

The role of RNA-binding proteins (RBPs) in bladder cancer (BC) remains unclear. Therefore, we analyzed the clinical information and RNA sequencing data from patients with BC and identified RBPs that may be promising predictors of BC.

Abstract

RBPs in the development and progression of BC remains unclear. Here, we elucidated the role of RBPs in predicting the survival of patients with BC. Clinical information and RNA sequencing data of the training and validation cohorts were downloaded from the Cancer Genome Atlas and Gene Expression Omnibus databases, respectively. Survival-related differentially expressed RBPs were identified using Cox regression analyses. A total of 113 upregulated and 54 downregulated RBPs were observed, with six showing prognostic values (AHNAK, MAP1B, LAMA2, P4HB, FASN, and GSDMB). In both the GSE32548 and GSE31684 datasets, patients with low-risk scores in survival-related six RBPs-based prognostic model showed longer overall survival than those with high-risk scores. AHNAK, MAP1B, P4HB, and FASN expression were significantly upregulated in both BC tissues and cell lines. BC tissues from high-risk group showed higher proportions of naive CD4+ T cells, M0 and M2 macrophages, and neutrophils and lower proportions of plasma cells, CD8+ T cells, and T-cell follicular helper compared to low-risk group. AHNAK knockdown significantly inhibited the proliferation, invasion, and migration of BC cells in vitro and inhibited the growth of subcutaneous tumors in vivo. We thus developed and functionally validated a novel six RBPs-based prognostic model for BC.

LncRNA DLEU2 silencing impedes the migration, invasion and EMT in gastric cancer cell by suppressing PI3K/AKT signaling pathway

Context: The high expression of long non-coding RNA deleted in lymphocytic leukaemia 2 (lncRNA DLEU2) has been confirmed in gastric cancer (GC).Objective: However, the detailed mechanism concerning its involvement in GC remained unclear, which we aimed to explore in this study.Materials and methods: LncRNA DLEU2 expression in GC was estimated by bioinformatic analysis, and the relationship between the expression of DLEU2 and the clinicopathological characteristics of patients with GC was performed. qRT-PCR was employed to detect the expression of lncRNA DLEU2 and confirm the transfection efficiency following the knockdown or overexpression of DLEU2. Functional assays, including CCK-8, flow cytometry, scratching test and Transwell assays, were used to determine the role of DLEU2 in tumor phenotypes. The effects of DLEU2 on the PI3K/Akt pathway were detected by western blot. For elucidating the functions of DLEU2/PI3K/Akt axis in GC, we inhibited the PI3K/Akt pathway in rescue experiments, and evaluated the expression levels of epithelial-mesenchymal transition (EMT)-related proteins by western blot.Results: The expression of DLEU2 was aberrantly up-regulated in GC tissues and cells, which was correlated with the degree of tumor differentiation, cancer antigen 19-9 (CA19-9) and Lauren histologic classification of patients with GC. Silencing of DLEU2 induced apoptosis, attenuated viability, migration and invasion as well as inhibited the PI3K/Akt signaling pathway in GC cells. Mechanistically, the DLEU2/PI3K/Akt axis promoted the progression of GC and the EMT by down-regulating the expression of E-Cadherin and up-regulating those of N-Cadherin and Vimentin.Discussion and conclusions: LncRNA DLEU2 promoted the migration, invasion and EMT in GC by activating the PI3K/Akt pathway.

Genome-Wide Identification of Long Noncoding RNA and Their Potential Interactors in ISWI Mutants

Long non-coding RNAs (lncRNAs) have been identified as key regulators of gene expression and participate in many vital physiological processes. Chromatin remodeling, being an important epigenetic modification, has been identified in many biological activities as well. However, the regulatory mechanism of lncRNA in chromatin remodeling remains unclear. In order to characterize the genome-wide lncRNA expression and their potential interacting factors during this process in Drosophila, we investigated the expression pattern of lncRNAs and mRNAs based on the transcriptome analyses and found significant differences between lncRNAs and mRNAs. Then, we performed TSA-FISH experiments of candidate lncRNAs and their potential interactors that have different functions in Drosophila embryos to determine their expression pattern. In addition, we also analyzed the expression of transposable elements (TEs) and their interactors to explore their expression in ISWI mutants. Our results provide a new perspective for understanding the possible regulatory mechanism of lncRNAs and TEs as well as their targets in chromatin remodeling.

LINC00922 acts as a novel oncogene in gastric cancer

Background

Long non-coding RNAs (lncRNAs) have been discovered to participate in various cancer developments. However, the biological function of lncRNAs associated with gastric cancer (GC) has not been fully elucidated.

Methods

Quantitative RT-PCR (qRT-PCR) assay was performed to measure lncRNAs, microRNAs (miRNAs) and message RNA (mRNA) expression. Cell Counter Kit-8 (CCK-8), clone formation, wound healing, and transwell assays were performed to investigate cell proliferation, migration, invasion, and apoptosis. Fluorescence in situ hybridization (FISH) assay was used to analyze LINC00922 in either the cytoplasm or nucleus. The potential binding among lncRNA, miRNA, and mRNA was evidenced by bioinformatics, luciferase reporter assay. Mouse-xenograft experiments were used to explore the tumorigenesis in vivo.

Results

LINC00922 was upregulated in GC, and high LINC00922 expression was associated with poor prognosis. Inhibition of LINC00922 suppressed GC cell proliferation, migration, invasion, and activated cell apoptosis in vitro and inhibited tumorigenesis in vivo. Besides, LINC00922 was markedly located in the cytoplasm. The mechanistic analysis demonstrated that LINC00922 acted as a sponge of miR-204-5p, thereby inhibiting the expression of the target gene-High Mobility Group AT-hook 2 (HMGA2).

Conclusion

LINC00922 accelerated the progression of GC by miR-204-5p/HMGA2 axis. These findings support LINC00922 may be a promising option for the diagnosis and therapy of GC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02569-3.

LncRNA HOTAIR influences cell proliferation via miR-130b/PTEN/AKT axis in IDD

Intervertebral disc degeneration (IDD) constitutes the pathological foundation of most musculoskeletal disorders of the spine. Previous studies have noted that cell proliferation is a common feature of IDD. Bioinformatics indicated that aberrantly expressed long non-coding RNAs (lncRNAs) were involved in the development of IDD. In this study, we aimed to investigate the function of lncRNA HOTAIR in the proliferation of human nucleus pulposus (NP) cells of IDD in vitro and further clarified its mechanism. The expression of HOTAIR and miR-130b was quantified by qRT-PCR in nucleus pulposus (NP) tissues. Furthermore, NP cells proliferation were assayed by CCK8 and Immunostaining. Dual-luciferase reporter and RIP assay were used to examine the expression of HOTAIR, PTEN, and their co-target gene miR-130b. Western blotting was used to test AKT expression. Our in vitro experiments on human normal NP cells observed that HOTAIR was significantly dysregulated in IDD. Further, HOTAIR can suppress proliferation by directly targeting miR-130b. In addition, Both HOTAIR and PTEN were confirmed to target miR-130b, and miR-130b upregulation reversed the phenomenon of ectopic expression of HOTAIR. More importantly, HOTAIR upregulation significantly reduced CyclinD1 protein expression by PTEN/AKT signaling pathway. Our findings suggest that HOTAIR may bind to miR-130b and subsequently increased CyclinD1 expression via PTEN/Akt pathway. Thereby, HOTAIR could become a potential target for the treatment of IDD.Abbreviations : IDD; intervertebral disc degeneration ncRNAs; non-coding RNAs lncRNAs; long non-coding RNAs miRNAs; microRNAs NP; nucleus pulposus qRT-PCR; quantitative reverse transcription-PCR LBP; Low back pain ORF; open reading frame HOTAIR; Hox transcript antisense intergenic RNA FAF1; Fas-associated protein factor-1 Erk; extracellular signal-regulated kinase TUG1; Taurine Up-regulated Gene 1 HIF1A hypoxia-inducible factor 1-alpha PI3K; phosphoinositide-3 kinase AIS; adolescent idiopathic scoliosis ECM; extracellular matrix LN;lupus nephritis CT;computed tomography MRI; magnetic resonance imaging PBS; phosphate-buffered salin PBS; phosphate-buffered salin PVDF; polyvinylidene fluoride TBST; Tris-buffered saline Tween ECL; enhanced chemiluminescence RIP; RNA immunoprecipitation.

LncRNA GACAT3: A Promising Biomarker and Therapeutic Target in Human Cancers

Long non-coding RNAs (lncRNAs) are a class of functional RNA molecules that do not encode proteins and are composed of more than 200 nucleotides. LncRNAs play important roles in epigenetic and gene expression regulation. The oncogenic lncRNA GACAT3 was recently discovered to be dysregulated in many tumors. Aberrant expression of GACAT3 contributes to clinical characteristics and regulates multiple oncogenic processes. The association of GACAT3 with a variety of tumors makes it a promising biomarker for diagnosis, prognosis, and targeted therapy. In this review, we integrate the current understanding of the pathological features, biological functions, and molecular mechanisms of GACAT3 in cancer. Additionally, we provide insight into the utility of GACAT3 as an effective diagnostic and prognostic marker for specific tumors, which offers novel opportunities for targeted therapeutic intervention.

LncRNA DLGAP1-AS2 overexpression associates with gastric tumorigenesis: a promising diagnostic and therapeutic target

BACKGROUND

Aberrant expression of long noncoding RNAs (lncRNAs) is associated with the progression of human cancers, including gastric cancer (GC). The function of lncRNA DLGAP1-AS2, as a promising oncogene, has been identified in several human cancers. Therefore, this study was aimed to explore the association of DLGAP1-AS2 with gastric tumorigenesis, as well.

METHODS AND RESULTS

The expression level of DLGAP1-AS2 was initially pre-evaluated in GC datasets from Gene Expression Omnibus (GEO). Moreover, qRT-PCR experiment was performed on 25 GC and 25 adjacent normal tissue samples. The Cancer Genome Atlas (TCGA) data were also analyzed for further validation. Consistent with data obtained from GEO datasets, qRT-PCR results revealed that DLGAP1-AS2 was significantly (p < 0.0032) upregulated in GC specimens compared to normal samples, which was additionally confirmed using TCGA analysis (p < 0.0001). DLGAP1-AS2 expression level was also correlated with age (p = 0.0008), lymphatic and vascular invasion (p = 0.0415) in internal samples as well as poor survival of GC patients (p = 0.00074) in GEO datasets. Also, Gene Ontology analysis illustrated that DLGAP1-AS2 may be involved in the cellular process, including hippo signaling, regulated by YAP1, as its valid downstream target, in GC samples. Moreover, ROC curve analysis showed the high accuracy of the DLGAP1-AS2 expression pattern as a diagnostic biomarker for GC.

CONCLUSION

Our findings indicated that DLGAP1-AS2 might display oncogenic properties through gastric tumorigenesis and could be suggested as a therapeutic, diagnostic, and prognostic target.

Long non-coding RNA CCL2 promoted gastric cancer function via miR-128/ PARP2 signal pathway

Amounts of studies have revealed long non-coding RNA (lncRNA) was related to the development of gastric cancer. Here, our results suggested the function and regulatory mechanism of CCL2 in gastric cancer. Quantitative polymerase-chain reaction (qPCR) was employed to inspect lncRNA CCL2 and miR-128 expression in normal gastric cell line (GES-1) and tumor cell lines (HGC-27 and MKN-45). The effects of CCL2 and miR-128 were measured via Luciferase reporter test. Western blot was used to check PARP2 protein expression. CCL2 expression and PARP2 protein levels were up-regulated, while miR-128 expression was obviously lower. Meanwhile, CCL2 down-regulating significantly repressed the proliferation, migration, and invasion by regulating miR-128. In addition, we proved miR-128 was a direct target of CCL2 through double luciferase assay and bioinformatics analysis. Moreover, miR-128 markedly inhibited the proliferation, migration, and invasion in gastric cancer. More importantly, miR-128 could reverse the effects of lncRNA CCL2 knocked down. PARP2-si obviously suppressed in gastric cancer proliferation, migration, and invasion. Meanwhile, miR-128 mimic and the knockout of CCL2 distinctly decreased PARP2 protein level. Additionally, luciferase report experiments certificated that PARP2 targeted miR-128, implying PARP2 directly interacted with miR-128 in gastric cancer. More interestingly, the downregulation of PARP could reverse the trend triggered by miR-128 inhibitor in gastric tumor. All over these results showed lncRNA CCL2 played importance of role in gastric tumor via miR-128/PARP2 axis signal pathway. LncRNA CCL2 accelerated gastric cancer progression by regulating miR-128/PARP2 signaling pathway, providing a novel possible strategy for the treatment of gastric cancer.

LncRNA SNHG12 in extracellular vesicles derived from carcinoma-associated fibroblasts promotes cisplatin resistance in non-small cell lung cancer cells

Non-small-cell lung cancer (NSCLC) is defined as the most universally diagnosed class of lung cancer. Cisplatin (DDP) is an effective drug for NSCLC, but tumors are prone to drug resistance. The current study set out to evaluate the regulatory effect of long non-coding RNA (lncRNA) small nucleolar RNA host gene 12 (SNHG12) in extracellular vesicles (EVs) derived from carcinoma-associated fibroblasts (CAFs) on DDP resistance in NSCLC cells. Firstly, NSCLC cells were treated with EVs, followed by detection of cell activity, IC50 values, cell proliferation and apoptosis, and Cy3-SNHG12. We observed that CAFs-EVs promoted IC50 values and cell proliferation and inhibited apoptosis. In addition, we learned that lncRNA SNHG12 carried by CAFs-EVs into NSCLC facilitated DDP resistance of NSCLC cells. Furthermore, ELAV like RNA binding protein 1 (HuR/ELAVL1) binding to lncRNA SNHG12 and X-linked inhibitor of apoptosis (XIAP) was verified and RNA stability of XIAP was also verified CAFs-EVs promoted RNA stability and transcription of XIAP, while silencing HuR could partially-reverse this promoting effect. Further joint experimentation showed that silencing XIAP partially inhibited DDP resistance in NSCLC cells. Additionally, the tumor growth and the positive rate of Ki67 and HuR were detected, which showed that CAFs-oe-EVs promoted the tumor and the positive rate of Ki67, as well as the levels of lncRNA SNHG12, HuR, and XIAP in vivo. Collectively, our findings indicated that lncRNA SNHG12 carried by CAFs-EVs into NSCLC cells promoted RNA stability and XIAP transcription by binding to HuR, thus augmenting DDP resistance in NSCLC cells.

Hsa_circ_0017728 as an oncogene in gastric cancer by sponging miR-149 and modulating the IL-6/STAT3 pathway

INTRODUCTION

Circular RNAs (circRNAs) have been identified as competing endogenous RNAs (ceRNAs) to mediate gene expression participating in the progression of multiple cancers, including gastric carcinoma (GC). However, the underlying molecular mechanisms by which circRNAs-modulated cell proliferation and apoptosis in GC had not been completely clarified. In our study, hsa_circ_0017728 as a potential oncogene competing endogenous RNA (ceRNA) was investigated in the progression and development of gastric carcinogenesis.

MATERIAL AND METHODS

High-throughput sequencing was used to determine differentially expressed circRNAs in GC tissues and corresponding non-cancerous tissues. The CCK-8 assay and Annexin V-fluorescein isothiocyanate/polyimide (Annexin V-FITC/PI) staining were performed to detect the cell viability and apoptosis in GC cells. In addition, gene expression and protein levels in GC tissues and cell lines were measured using RT-qPCR and western blotting, respectively.

RESULTS

Our results demonstrated that the hsa_circ_0017728 expression level was up-regulated in GC tissues and cell lines and closely associated with poor overall survival and pathological differentiation, higher TNM stage and lymph node metastasis. Knockdown of hsa_circ_0017728 had the ability to cause inhibition of cell proliferation and migration and elevate the cell apoptosis rate in GC cells. We also discovered that hsa_circ_0017728 might serve as a ceRNA to sponge miR-149 and indirectly regulated the IL-6/STAT3 signaling pathway in GC cell proliferation and apoptosis.

CONCLUSIONS

The regulatory network of hsa_circ_0017728/miR-149/IL-6/STAT3 cascade signaling might provide a better understanding of gastric carcinogenesis and progression.

The Roles and Mechanisms of lncRNAs in Liver Fibrosis

Long non-coding RNAs (lncRNAs) can potentially regulate all aspects of cellular activity including differentiation and development, metabolism, proliferation, apoptosis, and activation, and benefited from advances in transcriptomic and genomic research techniques and database management technologies, its functions and mechanisms in physiological and pathological states have been widely reported. Liver fibrosis is typically characterized by a reversible wound healing response, often accompanied by an excessive accumulation of extracellular matrix. In recent years, a range of lncRNAs have been investigated and found to be involved in several cellular-level regulatory processes as competing endogenous RNAs (ceRNAs) that play an important role in the development of liver fibrosis. A variety of lncRNAs have also been shown to contribute to the altered cell cycle, proliferation profile associated with the accelerated development of liver fibrosis. This review aims to discuss the functions and mechanisms of lncRNAs in the development and regression of liver fibrosis, to explore the major lncRNAs involved in the signaling pathways regulating liver fibrosis, to elucidate the mechanisms mediated by lncRNA dysregulation and to provide new diagnostic and therapeutic strategies for liver fibrosis.

Nuclear Paraspeckle Assembly Transcript 1 Enhances Hydrogen Peroxide-Induced Human Vascular Smooth Muscle Cell Injury by Regulating miR-30d-5p/A Disintegrin and Metalloprotease 10

BACKGROUND

Nuclear paraspeckle assembly transcript 1 (NEAT1) has been reported to be involved in the progression of many cancers; however, the role and mechanisms underlying NEAT1 in abdominal aortic aneurysm (AAA) remain unclear.Methods and Results:The expression of NEAT1, miR-30d-5p and A disintegrin and metalloprotease 10 (ADAM10) was measured by qRT-PCR and western blot. Functional experiments were conducted by using a CCK-8 assay, EDU assay, flow cytometry, western blot, ELISA, and commercial kits. The target relation was confirmed by dual-luciferase reporter assay and the RIP assay. It was then found that NEAT1 was upregulated in peripheral blood of AAA patients ~3.46-fold, smooth muscle cells (SMCs) isolated from AAA tissues ~2.6-fold and in a hydrogen peroxide (H₂O₂)-induced injury model of human vascular SMC (HVSMCs) ~2.0- and 3.9-fold at 50 µmol/L and 200 µmol/L H₂O₂treatment, respectively. NEAT1 deletion attenuated H₂O₂-induced cell proliferation promotion (40.0% vs. 74.3%), apoptosis inhibition (25.0% vs. 13.5%), and reduction of inflammatory response and oxidative stress in HVSMCs. Mechanistically, NEAT1 targeted miR-30d-5p to prevent the degradation of its target, ADAM10, in HVSMCs. Further rescue experiments suggested miR-30d-5p inhibition mitigated the effects of NEAT1 deletion on H₂O₂-induced HVSMCs. Moreover, ADAM10 overexpression counteracted the inhibitory functions of miR-30d-5p on H₂O₂-evoked HVSMC injury.

CONCLUSIONS

NEAT1 promoted H₂O₂-induced HVSMC injury by inducing cell apoptosis, inflammation and oxidative stress through miR-30d-5p/ADAM10 axis, indicating the possible involvement of NEAT1 in the pathogenesis of AAA.

Prognostic Value of LncRNA KRT18P55 in Patients with Intestinal Type of Gastric Cancer

PURPOSE

Gastric cancer (GC) is a heterogeneous disease, and this heterogeneity significantly affects survival and treatment outcomes. Identification of molecular biomarkers specific for early-stage GC can help clinicians to choose more precise and effective treatment approaches. Long non-coding RNAs (lncRNAs) have the potential to be used as biomarkers because of their tissue specificity, stability, and availability in body fluids. In this study, we aimed to investigate changes in the expression levels of lncRNA KRT18P55 and to assess its biomarker potentials in patients with GC.

METHODS

Tumor and non-tumor marginal tissues were collected from 102 patients at Noor-Nejat Hospital (Tabriz, Iran). RNA was isolated, and quantitative reverse transcriptase PCR (qRT-PCR) was performed to assess KRT18P55 expression levels in tumor and non-tumor tissue samples. The receiver operating characteristic (ROC) curve analysis was performed to evaluate potentials of KRT18P55 as a prognostic biomarker in GC. SPSS and GraphPad Prism software were used for data analysis.

RESULTS

We found that KRT18P55 is significantly overexpressed in tumor as compared to non-tumor tissues (p < 0.0001). We found a significant association between KRT18P55 overexpression and intestinal GC subtype (p < 0.0001), lymph node metastasis (p = 0.013), and Helicobacter pylori infection (p = 0.033). Based on the ROC analysis, KRT18P55 showed a sensitivity and specificity of 53.92% and 77.45%, respectively.

CONCLUSION

Overexpression of KRT18P55 in gastric tumors is suggestive of its oncogenic role in GC. In addition, KRT18P55 may be used as a potential prognosis biomarker and therapeutic target in intestinal GC subtype.

SLCO4A1-AS1 Facilitates the Malignant Phenotype via miR-149-5p/STAT3 Axis in Gastric Cancer Cells

Solute carrier organic anion transporter family member 4A1 (SLCO4A1-AS1), a newly discovered lncRNA, may exert effects in tumors. Since its role in gastric cancer remains obscure, we sought to explore the mechanism of SLCO4A1-AS1 in gastric cancer. The relationship among SLCO4A1-AS1, miR-149-5p, and STAT3 was detected by bioinformatics, dual luciferase analysis, and Pearson's test, and the expressions of these genes were determined by quantitative real-time PCR and Western blot. Moreover, CCK-8, flow cytometry, wound healing assay, and Transwell analysis were performed to verify the function of SLCO4A1-AS1 in gastric cancer. Rescue experiments were used to detect the role of miR-149-5p. The expressions of SLCO4A1-AS1 and STAT3 were increased, while the expression of miR-149-5p was suppressed in gastric cancer tissues and cell lines. In addition, STAT3 expression was negatively correlated with miR-149-5p expression but was positively correlated with SLCO4A1-AS1 expression. Overexpression of SLCO4A1-AS1 promoted cell viability, migration, invasion, and STAT3 expression but suppressed apoptosis, while knockdown of SLCO4A1-AS1 had the opposite effect. SLCO4A1-AS1 bound to miR-149-5p and targeted STAT3. Moreover, miR-149-5p mimic inhibited the malignant development of gastric cancer cells and obviously reversed the function of SLCO4A1-AS1 overexpression. Our research reveals that abnormally increased SLCO4A1-AS1 expression may be an important molecular mechanism in the development of gastric cancer.

Long Non-Coding RNA, Small Nucleolar RNA Host Gene 5, Inhibits the Oxidized Low-Density Lipoprotein Induced Vascular Endothelial Cell Injury by Targeting miR-26a-5p

Atherosclerosis is the major cause of cardiovascular disease, and endothelial cell injury is the primary atherogenic factor. Long non-coding RNAs (lncRNAs) are increasingly implicated as critical regulators of disease progression. Still, the role of lncRNA in endothelial cell injury is largely unknown. This issue was explored in control, ox-LDL stimulated, ox-LDL stimulated+transfected negative control vector, and ox-LDL stimulated+SNHG5 overexpression vector EA. hy926 cells. Quantitative real-time PCR used to assess the expression of SNHG5 and miR-26a-5p. Flow cytometry was used to evaluate cell apoptosis. Activity or concentration of SOD, MDA, CAT, and reactive oxygen species (ROS) was measured to assess oxidative stress. Western blotting was used to examine protein-level expression of cleaved Caspase-3, cleaved Caspase-9, and cyt-c in cytoplasm and mitochondria. Potential binding sites between SNHG5 and miR-26a-5p were predicted using Starbase software, and dual-luciferase reporter assays were used to identify target relationships. SNHG5 expression in cells following ox-LDL treatment was downregulated in EA. hy926 cells. Ox-LDL treatment promotes apoptosis, and increased C-Caspase-3, C-Caspase-9, and cytoplasmic cyt-c protein levels. MDA concentration and ROS activity were increased, while the activity of SOD and CAT was decreased. Transfection with SNHG5 reversed the effects of ox-LDL on cell apoptosis and oxidative stress. SNHG5 targeted miR-26a-5p and regulated its expression. miR-26a-5p mimics reversed SNHG5 modulation of apoptosis and oxidative stress. lncRNA SNHG5 targets to miR-26a-5p to regulate vascular endothelial cell injury induced by ox-LDL.

Exosomal long non-coding RNAs: Emerging players in cancer metastasis and potential diagnostic biomarkers for personalized oncology

Metastasis is a major challenge in the treatment of cancer. Exosomes are a class of small extracellular vesicles (EVs) that play critical roles in several human diseases, especially cancer, by transferring information (e.g., DNA, RNA, and protein) via cell-to-cell communication. Numerous recent studies have shown that exosomal long non-coding RNAs (lncRNAs) play crucial regulatory roles in cancer metastasis in the tumor microenvironment by altering the expression of several key signaling pathways and molecules. Due to their specificity and sensitivity, exosomal lncRNAs have potential as novel tumor markers and therapeutic targets in the treatment of cancer metastasis. In this review, we aim to summarize the roles of exosomal lncRNAs in cancer metastasis, the mechanisms underlying their roles, and their potential clinical applications.

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

Background

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

Methods

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

Results

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

Conclusions

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

Long non-coding RNA SNHG16 as a potential biomarker in hepatocellular carcinoma: A meta-analysis

Small nucleolar RNA host gene 16 (SNHG16) has recently been reported as a potential biomarker in various cancers. However, the prognostic value of SNHG16 in hepatocellular carcinoma (HCC) has not been investigated yet. Therefore, the purpose of this study was to reveal the association between SNHG16 expression and clinicopathological characteristics of HCC.Standards-compliant literature was retrieved from multiple public databases, and data on overall survival, disease-free survival, and clinicopathological characteristics related to SNGH16 were extracted and meta-analysis was performed. Additionally, the Cancer Genome Atlas data were analyzed through the gene expression profiling interactive analysis database to verify previous results.A total of 5 reports involving 410 patients with HCC were enrolled. The high expression of SNHG16 indicated worse overall survival (hazard ratio, 2.10; 95% CI, 1.22-3.60; P = .007) and disease-free survival (hazard ratio, 3.38; 95% CI, 1.10-10.40; P = .03). Additionally, the high expression of SNHG16 predicted a larger tumor size, metastasis, and advanced TNM stage.SNHG16 could serve as a potential biomarker of poor prognosis in HCC.

A Novel Regulatory Player in the Innate Immune System: Long Non-Coding RNAs

Long non-coding RNAs (lncRNAs) represent crucial transcriptional and post-transcriptional gene regulators during antimicrobial responses in the host innate immune system. Studies have shown that lncRNAs are expressed in a highly tissue- and cell-specific- manner and are involved in the differentiation and function of innate immune cells, as well as inflammatory and antiviral processes, through versatile molecular mechanisms. These lncRNAs function via the interactions with DNA, RNA, or protein in either cis or trans pattern, relying on their specific sequences or their transcriptions and processing. The dysregulation of lncRNA function is associated with various human non-infectious diseases, such as inflammatory bowel disease, cardiovascular diseases, and diabetes mellitus. Here, we provide an overview of the regulation and mechanisms of lncRNA function in the development and differentiation of innate immune cells, and during the activation or repression of innate immune responses. These elucidations might be beneficial for the development of therapeutic strategies targeting inflammatory and innate immune-mediated diseases.

The regulatory relationship and function of LncRNA FAM225A-miR-206-ADAM12 in gastric cancer

OBJECTIVE

To investigate the role and functions of FAM225A in gastric cancer.

METHODS

The expressions of FAM225A, miR-206, ADAM12 and epithelial-mesenchymal transition (EMT)-related genes were detected by quantitative real-time PCR and Western blot. Functional experiments including cell counting kit-8, colony formation, wound-healing, and Transwell assays were conducted to analyze the biological characteristics of gastric cancer cells in different groups. Bioinformatics, dual-luciferase reporter assay and Pearson correlation coefficients were performed for determining the regulatory relationship of lncRNA-miRNA-mRNA. In vivo nude mouse xenografts and immunohistochemistry were used to verify the results in vitro.

RESULTS

In gastric cancer, FAM225A and ADAM12 expressions were up-regulated, while miR-206 expression was down-regulated. Opposite to the regulatory effects of overexpressed FAM225A, blocking FAM225A expression reduced cell viability, migration, invasion and number of cell clones, increased E-Cadherin expression, inhibited N-Cadherin and Vimentin expressions, and ultimately promoted tumor growth. MiR-206 inhibitor partially offset the effects of siFAM225A. Moreover, FAM225A competitively bound to miR-206 to up-regulate ADAM12 expression. Overexpressed ADAM12 partially reversed the effect of miR-206 mimic on the biological characteristics of gastric cancer cells and EMT-related proteins.

CONCLUSION

Our research revealed that FAM225A-miR-206-ADAM12 axis may be a potential pathway for regulating gastric cancer.

LncRNA as a multifunctional regulator in cancer multi-drug resistance

BACKGROUND

Malignant tumors have become the most dangerous disease in recent years. Chemotherapy is the most effective treatment for this disease; however, the problem of drug resistance has become even more common, which leads to the poor prognosis of patients suffering from cancers. Thus, necessary measures should be taken to address these problems at the earliest. Many studies have demonstrated that drug resistance is closely related to the abnormal expressions of long non-coding RNAs (lncRNAs).

METHODS AND RESULTS

This review aimed to summarize the molecular mechanisms underlying the association of lncRNAs and the development of drug resistance and to find potential strategies for the clinical diagnosis and treatment of cancer drug resistance. Studies showed that lncRNAs can regulate the expression of genes through chromatin remodeling, transcriptional regulation, and post-transcriptional processing. Furthermore, lncRNAs have been reported to be closely related to the occurrence of malignant tumors. In summary, lncRNAs have gained attention in related fields during recent years. According to previous studies, lncRNAs have a vital role in several different types of cancers owing to their multiple mechanisms of action. Different mechanisms have different functions that could result in different consequences in the same disease.

CONCLUSIONS

LncRNAs closely participated in cancer drug resistance by regulating miRNA, signaling pathways, proteins, cancer stem cells, pro- and ant-apoptosis, and autophagy. lncRNAs can be used as biomarkers of the possible treatment target in chemotherapy, which could provide solutions to the problem of drug resistance in chemotherapy in the future.

Expression and Clinical Value of LncRNA GAPLINC in Esophageal Squamous Cell Carcinoma

Background

The long noncoding RNA (lncRNA) GAPLINC, or gastric adenocarcinoma predictive long intergenic ncRNA, plays a carcinogenic role in a variety of different tumor types. There is limited information regarding the biological function of GAPLINC in the development of esophageal squamous cell carcinoma (ESCC).

Methods

Surgical tissue samples of 40 patients undergoing ESCC radical surgery were collected, including ESCC tissues and corresponding adjacent normal tissues. Quantitative real-time PCR (qRT-PCR) was used to detect the expression of lncRNA GAPLINC in the human ESCC cell line (TE11). The function role of LncRNA GAPLINC was detected after specific siRNA interference and overexpression in the TE11 cell line. The effects of LncRNA GAPLINC on ESCC cell proliferation, migration and invasion abilities were investigated by flow cytometry, using the Cell Counting Kit-8 (CCK-8), and by Transwell migration assays, respectively.

Results

The expression of lncRNA GAPLINC in ESCC tissues was significantly higher than that in corresponding adjacent normal tissues (P<0.05) and correlated with the degree of tumor differentiation (P<0.05). Compared with human esophageal normal epithelial cell lines, the expression of LncRNA GAPLINC was significantly higher in the human ESCC cell line (P<0.05). CCK-8 assays showed that LncRNA GAPLINC overexpression increased the growth rate of cells (P<0.05). Transwell experiments showed that LncRNA GAPLINC overexpression increased the ability of cell migration and invasion compared to control cells (P<0.05). Annexin V assay revealed that LncRNA GAPLINC silencing increased early stage apoptosis (P<0. 05).

Conclusion

Our results suggest that LncRNA GAPLINC may be used as a biomarker for the diagnosis and monitoring of ESCC, and may play an oncogenic role in ESCC.

TINCR inhibits the proliferation and invasion of laryngeal squamous cell carcinoma by regulating miR-210/BTG2

Background

Terminal differentiation-induced ncRNA (TINCR) plays an essential role in epidermal differentiation and is involved in the development of various cancers.

Methods

qPCR was used to detect the expression level of TINCR in tissues and cell lines of laryngeal squamous cell carcinoma (LSCC). The potential targets of TINCR were predicted by the bioinformation website. The expression of miR-210 and BTG2 genes were detected by qPCR, and the protein levels of BTG2 and Ki-67 were evaluated by western blot. CCK-8 assay, scratch test, and transwell chamber were used to evaluate the proliferation, invasion, and metastasis ability of LSCC cells. The relationships among TINCR, miR-210, and BTG2 were investigated by bioinformatics software and luciferase reporter assay. The in vivo function of TINCR was accessed on survival rate and tumor growth in nude mice.

Results

We used qRT-PCR to detect the expression of TINCR in laryngeal squamous cell carcinoma (LSCC) tissues and cells and found significantly lower levels in cancer tissues compared with adjacent tissues. Additionally, patients with high TINCR expression had a better prognosis. TINCR overexpression was observed to inhibit the proliferation and invasion of LSCC cells. TINCR was shown to exert its antiproliferation and invasion effects by adsorbing miR-210, which significantly promoted the proliferation and invasion of laryngeal squamous cells. Overexpression of miR-210 was determined to reverse the tumour-suppressive effects of TINCR. BTG2 (anti-proliferation factor 2) was identified as the target gene of miR-210, and BTG2 overexpression inhibited the proliferation and invasion of LSCC cells. BTG2 knockdown relieved the inhibitory effects of TINCR on the proliferation and invasion of LSCC. Finally, TINCR upregulation slowed xenograft tumour growth in nude mice and significantly increased survival compared with control mice.

Conclusion

The results of this study suggest that TINCR inhibits the proliferation and invasion of LSCC by regulating the miR-210/BTG2 pathway, participates in cell cycle regulation, and may become a target for the treatment of LSCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08513-0.

Generation of combined hepatocellular-cholangiocarcinoma through transdifferentiation and dedifferentiation in p53-knockout mice

The two principal histological types of primary liver cancers, hepatocellular carcinoma (HCC) and cholangiocarcinoma, can coexist within a tumor, comprising combined hepatocellular‐cholangiocarcinoma (cHCC‐CCA). Although the possible involvement of liver stem/progenitor cells has been proposed for the pathogenesis of cHCC‐CCA, the cells might originate from transformed hepatocytes that undergo ductular transdifferentiation or dedifferentiation. We previously demonstrated that concomitant introduction of mutant HRAS^V12 (HRAS) and Myc into mouse hepatocytes induced dedifferentiated tumors that expressed fetal/neonatal liver genes and proteins. Here, we examine whether the phenotype of HRAS‐ or HRAS/Myc‐induced tumors might be affected by the disruption of the Trp53 gene, which has been shown to induce biliary differentiation in mouse liver tumors. Hepatocyte‐derived liver tumors were induced in heterozygous and homozygous p53‐knockout (KO) mice by hydrodynamic tail vein injection of HRAS‐ or Myc‐containing transposon cassette plasmids, which were modified by deleting loxP sites, with a transposase‐expressing plasmid. The HRAS‐induced and HRAS/Myc‐induced tumors in the wild‐type mice demonstrated histological features of HCC, whereas the phenotype of the tumors generated in the p53‐KO mice was consistent with cHCC‐CCA. The expression of fetal/neonatal liver proteins, including delta‐like 1, was detected in the HRAS/Myc‐induced but not in the HRAS‐induced cHCC‐CCA tissues. The dedifferentiation in the HRAS/Myc‐induced tumors was more marked in the homozygous p53‐KO mice than in the heterozygous p53‐KO mice and was associated with activation of Myc and YAP and suppression of ERK phosphorylation. Our results suggest that the loss of p53 promotes ductular differentiation of hepatocyte‐derived tumor cells through either transdifferentiation or Myc‐mediated dedifferentiation.

A Non-Coding RNA Network Involved in KSHV Tumorigenesis

Regulatory pathways involving non-coding RNAs (ncRNAs), such as microRNAs (miRNAs) and long non-coding RNAs (lncRNA), have gained great relevance due to their role in the control of gene expression modulation. Using RNA sequencing of KSHV Bac36 transfected mouse endothelial cells (mECK36) and tumors, we have analyzed the host and viral transcriptome to uncover the role lncRNA-miRNA-mRNA driven networks in KSHV tumorigenesis. The integration of the differentially expressed ncRNAs, with an exhaustive computational analysis of their experimentally supported targets, led us to dissect complex networks integrated by the cancer-related lncRNAs Malat1, Neat1, H19, Meg3, and their associated miRNA-target pairs. These networks would modulate pathways related to KSHV pathogenesis, such as viral carcinogenesis, p53 signaling, RNA surveillance, and cell cycle control. Finally, the ncRNA-mRNA analysis allowed us to develop signatures that can be used to an appropriate identification of druggable gene or networks defining relevant AIDS-KS therapeutic targets.

Methylation and Noncoding RNAs in Gastric Cancer: Everything Is Connected

Despite recent progress, gastric cancer remains one of the most common cancers and has a high mortality rate worldwide. Aberrant DNA methylation pattern and deregulation of noncoding RNA expression appear in the early stages of gastric cancer. Numerous investigations have confirmed their significant role in gastric cancer tumorigenesis and their high potential as diagnostic and prognostic biomarkers. Currently, it is clear that these epigenetic regulators do not work alone but interact with each other, generating a complex network. The aim of our review was to summarize the current knowledge of this interaction in gastric cancer and estimate its clinical potential for the diagnosis, prognosis, and treatment of the disease.

Polymorphism of TUSC7 associated with gastric cancer susceptibility and binding with miR-133a-3p: a population-based case-control study

BACKGROUND

Previous studies have demonstrated that gene polymorphism is associated with cancer susceptibility. Most of these genes are involved in neoplastic processes. Previous studies demonstrated that tumor-suppressor candidate 7 (TUSC7) was a tumor-suppressor gene in various tumors. This study aims to explore the association between lncRNA TUSC7 polymorphism and gastric cancer susceptibility and the potential function.

METHODS

The tagging SNPs of TUSC7 were genotyped with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in a Chinese Han population-based case-control study. The relative expression level of TUSC7 in plasma was conducted by quantitative real-time PCR (qRT-PCR). The gene-environment interaction was analyzed by multifactor dimensionality reduction (MDR). The dual luciferase reporter assay was used to examine whether SNP rs12494960 of TUSC7 allele variation affected the binding of lncRNA-TUSC7 and miRNAs miR-133a-3p.

RESULTS

Three tagging SNPs (rs12494960, rs1518338, rs2867837) of TUSC7 were selected to validate in population. The unconditional multiple logistic regression showed that individuals with genotype AA (OR: 1.79, 95% CI: 1.16, 2.70) of rs12494960 and GG (OR: 2.24, 95% CI: 1.12, 4.46) of rs2867837 in TUSC7 had increased risk of GC susceptibility. The qRT-PCR showed that CA and AA genotype of rs12494960 in TUSC7 had significantly lower relative expression level in plasma, compared with CC genotype. The dual luciferase reporter assay showed that TUSC7 and miR-133a-3p had interaction.

CONCLUSION

The mutant genotype of rs12494960 could increase the susceptibility of gastric cancer and might affect the corresponding mRNA expression of lncRNA TUSC7 in plasma.