Role of non-coding RNAs in liver disease progression to hepatocellular carcinoma

Exploring the Putative Involvement of MALAT1 in Mediating the Beneficial Effect of Exendin-4 on Oleic Acid-Induced Lipid Accumulation in HepG2 Cells

Background/Objectives: The reduction of oleic acid (OA)-induced steatosis in HepG2 cells observed upon treatment with the glucagon-like peptide-1 receptor agonist (GLP-1RA) Exendin-4 (Ex-4) is associated with the modulation of the expression of several microRNAs, long non-coding RNAs (lncRNAs), and mRNAs. Notably, MALAT1, an lncRNA, shows significant downregulation in the presence of Ex-4 as compared to OA alone. In this study, we aimed to explore the role of MALAT1 in the positive impact of Ex-4 on OA-induced lipid accumulation in HepG2 cells. Methods: Steatosis in HepG2 cells was induced by treating them with 400 µM OA. The effect of Ex-4 on steatosis was examined by treating the steatotic cells with 200 nM of EX-4 for 3 h. MALAT1 was silenced with siRNA, while gene expression was quantified using qRT-PCR. Results: In the presence of Ex-4, the silencing of MALAT1 did not exert any discernible influence on de novo lipogenesis genes such as PPARγ and SREBP1. However, MALAT1 silencing significantly affected, to varying degrees, the expression levels of several lipid metabolism genes such as FAS, ACADL, CPT1A, and MTTP. Conclusions: Further investigations are warranted to fully decipher the role of the Ex-4-MALAT1 in the positive impact of GLP-1RAs on steatosis.

The interactive role of microRNA and other non-coding RNA in hepatitis B (HBV) associated fibrogenesis

One of the outstanding features of chronic hepatitis B infection (CHB) is its strong association with liver fibrosis. CHB induced inflammation and injury trigger multiple biochemical and physical changes that include the promotion of a wide range of cytokines, chemokines and growth factors that activate hepatic stellate cells (HSCs) CHB induced activation of hepatic stellate cells (HSCs) is regarded as a central event in fibrogenesis to directly promote the synthesis of myofibroblasts and the expression of a range of materials to repair injured liver tissue. Fibrogenesis is modulated by the mainstream epigenetic machinery, as well as by non-coding RNA (ncRNA) that are often referred to as an ancillary epigenetic response to fine tune gene expression. Although extensive research has explained the regulatory role of ncRNA in liver fibrogenesis, most of this research relates to non-CHB etiologies. This review paper outlines the complex interactive regulatory role of microRNA (miRNA) and their interaction with long non-coding RNA (lncRNA), circular RNA (circRNA) and the mainstream epigenetic machinery in CHB induced liver fibrosis. The paper also illustrates some of the difficulties involved in translating candidate ncRNA into approved drugs or diagnostic tools. In conclusion, the important regulatory role of ncRNA in CHB induced liver fibrosis warrants further investigation to exploit their undoubted potential as diagnostic and therapeutic agents.

Construction of a cell cycle-specific lncRNA-miRNA-mRNA network reveals novel key lncRNAs in colorectal cancer

OBJECTIVE

The current study aimed to determine the roles of pivotal and novel lncRNAs associated with the cell cycle in the occurrence and development of Colorectal cancer (CRC).

METHODS

The TCGA-COAD project related to CRC was downloaded, and differential expression analysis was performed to identify differentially expressed lncRNAs, miRNAs, and mRNAs. A cell cycle-associated lncRNA-miRNA-mRNA regulatory network was constructed, and two novel lncRNAs were selected. Two subnetworks were constructed for selected lncRNAs. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were illustrated for the genes in each sub-network. qPCR analysis was used to validate the expression levels of the selected lncRNAs in CRC tissues compared to those adjacent normal tissues.

RESULTS

The differential expression analysis identified 416 lncRNAs, 317 miRNAs, and 117 mRNAs. The ceRNA subnetwork genes were associated with different pathways, including cellular senescence, DNA replication, human T-cell leukemia virus 1 infection, and oocyte meiosis. The bioinformatic results based on the TCGA project indicated the dysregulation of two novel lncRNAs, MIR29B2CHG and HELLPAR, in CRC tissues compared to adjacent normal tissues. Moreover, qPCR confirmed the dysregulation of lncRNAs in the CRC tissues. ROC curves revealed that both selected lncRNAs had acceptable specificity and sensitivity as biomarkers.

CONCLUSION

In conclusion, novel cell cycle-associated lncRNAs have the potential to be understood as the underlying molecular mechanisms that influence CRC. Therefore, these lncRNAs can be considered as promising biomarkers for the diagnosis and treatment of CRC.

LncRNA NEAT1 in the pathogenesis of liver-related diseases

Nuclear paraspeckle assembly transcript 1 (NEAT1) is a long noncoding RNA (lncRNA) that is widely expressed in a variety of mammalian cell types. Altered expression levels of the lncRNA NEAT1 have been reported in liver-related disorders including cancer, fatty liver disease, liver fibrosis, viral hepatitis, and hepatic ischemia. lncRNA NEAT1 mostly acts as a competing endogenous RNA (ceRNA) to sponge various miRNAs (miRs) to regulate different functions. In regard to hepatic cancers, the elevated expression of NEAT1 has been reported to have a relation with the proliferation, migration, angiogenesis, apoptosis, as well as epithelial-mesenchymal transition (EMT) of cancer cells. Furthermore, NEAT1 upregulation has contributed to the pathogenesis of other liver diseases such as fibrosis. In this review, we summarize and discuss the molecular mechanisms by which NEAT1 contributes to liver-related disorders including acute liver failure, nonalcoholic fatty liver disease (NAFLD), liver fibrosis, and liver carcinoma, providing novel insights and introducing NEAT1 as a potential therapeutic target in these diseases.

Bioinformatics analysis of a disease-specific lncRNA-miRNA-mRNA regulatory network in recurrent spontaneous abortion (RSA)

BACKGROUND

This study investigated the molecular mechanisms of long non-coding RNAs (lncRNAs) in RSA using the lncRNA-miRNA-mRNA regulatory network.

METHODS

The present study obtained expression datasets of long non-coding RNAs (lncRNAs), messenger RNAs (mRNAs), and microRNAs (miRNAs) from blood samples of individuals with unexplained recurrent spontaneous abortion (RSA) and healthy controls. Differentially expressed lncRNAs (DELs), mRNAs (DEMs), and miRNAs (DEmiRs) were identified. A regulatory network comprising lncRNA, miRNA, and mRNA was constructed, and Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were conducted to analyze the biological functions of DEM. Also, a protein-protein interaction (PPI) network was made and key genes were identified.

RESULTS

A total of 57 DELs, 212 DEmiRs, and 301 DEMs regarding RSA were identified. Later analysis revealed a lncRNA-miRNA-mRNA network comprising nine lncRNAs, 14 miRNAs, and 65 mRNAs. Then, the ceRNA network genes were subjected to functional enrichment and pathway analysis, which showed their association with various processes, such as cortisol and thyroid hormone synthesis and secretion, human cytomegalovirus infection, and parathyroid hormone synthesis. In addition, ten hub genes (ITGB3, GNAI2, GNAS, SRC, PLEC, CDC42, RHOA, RAC1, CTNND1, and FN1) were identified based on the PPI network results.

CONCLUSION

In summary, the outcomes of our study provided some data regarding the alteration genes involved in RSA pathogenic mechanism via the lncRNA-miRNA-mRNA network and reveal the possibility of identifying new lncRNAs and miRNAs as promising molecular biomarkers.

Role of long non-coding RNAs in cholangiocarcinoma: A systematic review and meta-analysis

BACKGROUND

Cholangiocarcinoma (CCA), as a rare malignancy of the biliary tree, has a poor prognosis most of the time. CCA is highly epigenetically regulated and several long non-coding RNAs (lncRNA) have been investigated to have a diagnostic and prognostic role in CCA. The current study aimed to assess the studies finding relevant lncRNAs in CCA systematically.

METHODS

International databases, including PubMed, Cochrane Library, and Embase, were comprehensively searched in order to identify studies investigating any lncRNA in CCA. After screening by title/abstract and full-text, necessary data were extracted. Random-effect meta-analysis was performed for pooling the areas under the curve (AUCs), specificity, and sensitivity of lncRNAs for the diagnosis of CCA.

RESULTS

A total of 33 studies were chosen to be included in the final analysis, comprised of 2677 patients. Meta-analysis of AUCs for evaluation of CCA resulted in pooled AUC of 0.79 (95% CI: 0.75-0.82; I2 = 69.11, p < .01). Additionally, overall sensitivity of 0.80 (95% CI 0.75-0.84) and specificity of 0.77 (95% CI: 0.68-0.84) were observed. Measurement of lncRANs in the assessment of CCA also improved overall survival significantly (effect size 1.61, 95% CI: 1.39-1.82). A similar result was found for progression-free survival (effect size 1.57, 95% CI: 1.20-1.93).

CONCLUSION

Based on our findings, lncRNAs showed promising results as biomarkers in the diagnosis of CCA since they had acceptable sensitivity and specificity, in addition to the fact that improved survival in this poor prognosis cancer. Further studies might be needed to address this issue and find the best clinically useful lncRNA.

Functionalized Carbon Nanotubes for Delivery of Ferulic Acid and Diosgenin Anticancer Natural Agents

It was investigated whether loading multi-wall carbon nanotubes (CNTs) with two natural anticancer agents: ferulic acid (FUA) and diosgenin (DGN), may enhance the anticancer effect of these drugs. The CNTs were functionalized with carboxylic acid (CNTCOOH) or amine (CNTNH2), loaded with the above pro-drugs, as well as both combined and coated with chitosan or chitosan-stearic acid. Following physicochemical characterization, the drug-loading properties and kinetics of the drug's release were investigated. Their effects on normal human skin fibroblasts and MCF-7 breast carcinoma cells, HepG2 hepatocellular carcinoma cells, and A549 non-small-cell lung cancer cells were evaluated in vitro. Their actions at the molecular level were evaluated by assessing the expression of lncRNAs (HULC, HOTAIR, CCAT-2, H19, and HOTTIP), microRNAs (mir-21, mir-92, mir-145, and mir-181a), and proteins (TGF-β and E-cadherin) in HepG2 cells. The release of both pro-drugs depended on the glutathione concentration, coating, and functionalization. Release occurred in two stages: a no-burst/zero-order release followed by a sustained release best fitted to Korsmeyer-Peppas kinetics. The combined nanoformulation cancer inhibition effect on HepG2 cancer cells was more pronounced than for A549 and MCF7 cells. The combined nanoformulations had an additive impact followed by a synergistic effect, with antagonism demonstrated at high concentrations. The nanoformulation coated with chitosan and stearic acid was particularly successful in targeting HepG2 cells and inducing apoptosis. The CNT functionalized with carboxylic acid (CNTCOOH), loaded with both FUA and DGN, and coated with chitosan-stearic acid inhibited the expression of lncRNAs and modulated both microRNAs and proteins. Thus, nanoformulations composed of functionalized CNTs dual-loaded with FUA and DGN and coated with chitosan-stearic acid are a promising drug delivery system that enhances the activity of natural pro-drugs.

LncRNA AK142643 promotes hepatic lipid accumulation by upregulating CD36 via interacting with IGF2BP2

Excessive lipid accumulation in hepatocytes is a defining feature of non-alcoholic fatty liver disease (NAFLD), a condition that is becoming increasingly prevalent worldwide. While long non-coding RNAs (LncRNAs) have been implicated in hepatic lipid metabolism, the precise regulatory mechanisms they employ remain poorly understood. In this study, we investigate the role of AK142643, a previously uncharacterized LncRNA, in hepatic lipid metabolism and the development of NAFLD. Our results demonstrate that AK142643 is upregulated in the livers of ob/ob and high fat diet (HFD)-fed mice, and that it promotes hepatic lipid accumulation both in vivo and in vitro. Furthermore, we reveal that AK142643 acts through the insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2) to enhance the expression of fatty acid translocase (FAT)/CD36, a key regulator of lipid metabolism. Specifically, AK142643 facilitates the binding of IGF2BP2 to CD36 mRNA, thereby increasing its stability and promoting its expression. Taken together, these findings shed new light on the complex interplay between LncRNAs and hepatic lipid metabolism, and provide insights into the mechanisms underlying the development of NAFLD.

Novel delivery system with a dual–trigger release of savory essential oil by mesoporous silica nanospheres and its possible targets in leukemia cancer cells: in vitro study

Introduction

Essential oils (EOs) are complex structures and possess several pharmacological effects. Nanomedicine offers a solution for their major limitations, including poor solubility, volatility, and non–controlled release, preventing their clinical use.

Methods

Here, we developed a novel delivery system by nanoformulations that were prepared by impregnating savory essential oil (SA) into mesoporous silica nanoparticles (MSNs). The nanoformulations were characterized and examined for their anticancer activities on cancer cells (HepG2 liver and HL60 leukemia cells) and MRC5 normal cells. We further tested the mechanisms of action and possible molecular targets against HL60 cells.

Results

The results demonstrated that SA was governed by nanoformulations under the dual–trigger release of pH/glutathione, and it typically fit the Korsmeyer–Peppas kinetic model. The nanoformulations enhanced the anticancer effect against HepG2 cells and HL60 cells compared to SA but were less cytotoxic to MRC5 normal cells and regulated various molecular pathways of apoptosis. Most importantly, new results were obtained on the genetic regulation principle through the high inhibition of long noncoding RNAs (HOTAIR, HULC, CCAT1, and H19) and matrix metalloproteinases (MMP–2 and MMP–9), providing a novel leukemia target.

Conclusions

These results suggest potential impacts for nanoformulations composed of SA with a sustained release pattern controlled by dual–trigger release of pH/GSH that enhanced anticancer cells. This approach may offer a new route for using EOs as new targets for cancers and open the door for deep preclinical investigations.

Progress on traditional Chinese medicine in improving hepatic fibrosis through inhibiting oxidative stress

Hepatic fibrosis is a common pathological process that occurs in the development of various chronic liver diseases into cirrhosis and liver cancer, characterized by excessive deposition of the extracellular matrix. In the past, hepatic fibrosis was thought to be a static and irreversible pathological process. In recent years, with the rapid development of molecular biology and the continuous in-depth study of the liver at the microscopic level, more and more evidence has shown that hepatic fibrosis is a dynamic and reversible process. Therefore, it is particularly important to find an effective, simple, and inexpensive method for its prevention and treatment. Traditional Chinese medicine (TCM) occupies an important position in the treatment of hepatic fibrosis due to its advantages of low adverse reactions, low cost, and multi-target effectiveness. A large number of research results have shown that TCM monomers, single herbal extracts, and TCM formulas play important roles in the prevention and treatment of hepatic fibrosis. Oxidative stress (OS) is one of the key factors in the occurrence and development of hepatic fibrosis. Therefore, this article reviews the progress in the understanding of the mechanisms of TCM monomers, single herbal extracts, and TCM formulas in preventing and treating hepatic fibrosis by inhibiting OS in recent years, in order to provide a reference and basis for drug therapy of hepatic fibrosis.

Insight into the Inter-Organ Crosstalk and Prognostic Role of Liver-Derived MicroRNAs in Metabolic Disease Progression

Dysfunctional hepatic metabolism has been linked to numerous diseases, including non-alcoholic fatty liver disease, the most common chronic liver disorder worldwide, which can progress to hepatic fibrosis, and is closely associated with insulin resistance and cardiovascular diseases. In addition, the liver secretes a wide array of metabolites, biomolecules, and microRNAs (miRNAs) and many of these secreted factors exert significant effects on metabolic processes both in the liver and in peripheral tissues. In this review, we summarize the involvement of liver-derived miRNAs in biological processes with an emphasis on delineating the communication between the liver and other tissues associated with metabolic disease progression. Furthermore, the review identifies the primary molecular targets by which miRNAs act. These consolidated findings from numerous studies provide insight into the underlying mechanism of various metabolic disease progression and suggest the possibility of using circulatory miRNAs as prognostic predictors and therapeutic targets for improving clinical intervention strategies.

Hepatic Outcomes of Nonalcoholic Fatty Liver Disease Including Cirrhosis and Hepatocellular Carcinoma

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide and represents a significant cause of cirrhosis and hepatocellular carcinoma (HCC). Almost 20% of patients with NAFLD and advanced fibrosis develop cirrhosis, of which 20% can progress to decompensated liver stage. Although patients with cirrhosis or fibrosis continue to have a high risk for HCC progression, growing evidence shows that NAFLD-HCC can develop even in the absence of cirrhosis. Current evidence characterizes NAFLD-HCC primarily as a condition with late presentation, lower response to curative therapy, and poor prognosis.

A key driver to promote HCC: Cellular crosstalk in tumor microenvironment

Liver cancer is the third greatest cause of cancer-related mortality, which of the major pathological type is hepatocellular carcinoma (HCC) accounting for more than 90%. HCC is characterized by high mortality and is predisposed to metastasis and relapse, leading to a low five-year survival rate and poor clinical prognosis. Numerous crosstalk among tumor parenchymal cells, anti-tumor cells, stroma cells, and immunosuppressive cells contributes to the immunosuppressive tumor microenvironment (TME), in which the function and frequency of anti-tumor cells are reduced with that of associated pro-tumor cells increasing, accordingly resulting in tumor malignant progression. Indeed, sorting out and understanding the signaling pathways and molecular mechanisms of cellular crosstalk in TME is crucial to discover more key targets and specific biomarkers, so that develop more efficient methods for early diagnosis and individualized treatment of liver cancer. This piece of writing offers insight into the recent advances in HCC-TME and reviews various mechanisms that promote HCC malignant progression from the perspective of mutual crosstalk among different types of cells in TME, aiming to assist in identifying the possible research directions and methods in the future for discovering new targets that could prevent HCC malignant progression.

Identification of a novel circRNA-miRNA-mRNA regulatory axis in hepatocellular carcinoma based on bioinformatics analysis

In recent years, circular RNAs (circRNAs) have been found to play an essential regulatory role in hepatocellular carcinoma (HCC) through various mechanisms, particularly the endogenous competitive RNA (ceRNA) mechanism. Therefore, it is significant to explore the circRNAs in hepatoma. In this study, we constructed the ceRNA and survival network using Cytoscape. We also used R, Perl software, and multiple online databases and platforms, including Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG), to perform overall survival, immune cell infiltration, immune checkpoints, pathway activity, and anticancer drug sensitivity analysis of the genes. Finally, the receiver operator characteristic curve (ROC) analysis was performed to identify the diagnosis value of the genes. KEGG analysis revealed the T cell receptor signaling pathway as the main enrichment pathway. A total of 29 genes related to survival and prognosis were screened out. The findings suggest that ZNF544, WDR76, ACTG1, RASSF3, E2F3, ASRGL1, and POGK are associated with multilevel immune cell infiltration. Additionally, immune checkpoint analysis screened out the ACTG1, E2F3, RASSF3, and WDR76. It was also revealed that the WDR76, E2F3, ASRGL1, and POGK mainly activated the cell cycle and DNA damage response (DDR) pathway. The results suggest that the sensitivity toward trametinib, refametinib (RDEA119), and selumetinib correlates to the expression of WDR76. ROC analysis showed that the area under the curve (AUC) of all genes in the regulatory axis was greater than 0.7. The identified hsa_circ_0000417/hsa_circ_0002688/hsa_circ_0001387--hsa-miR-199a-5p--WDR76 regulatory axis may provide new insights into the progression, clinical diagnosis, and treatment of HCC.

Relevance of HBx for Hepatitis B Virus-Associated Pathogenesis

The hepatitis B virus (HBV) counts as a major global health problem, as it presents a significant causative factor for liver-related morbidity and mortality. The development of hepatocellular carcinomas (HCC) as a characteristic of a persistent, chronic infection could be caused, among others, by the pleiotropic function of the viral regulatory protein HBx. The latter is known to modulate an onset of cellular and viral signaling processes with emerging influence in liver pathogenesis. However, the flexible and multifunctional nature of HBx impedes the fundamental understanding of related mechanisms and the development of associated diseases, and has even led to partial controversial results in the past. Based on the cellular distribution of HBx-nuclear-, cytoplasmic- or mitochondria-associated-this review encompasses the current knowledge and previous investigations of HBx in context of cellular signaling pathways and HBV-associated pathogenesis. In addition, particular focus is set on the clinical relevance and potential novel therapeutic applications in the context of HBx.

Long non-coding RNA-LINC00941 promotes the proliferation and invasiveness of glioma cells

Glioma is one of the most common intracranial malignant tumors worldwide, accounting for 30%-40% of primary brain tumors. Long non-coding RNAs (lncRNAs) have been implicated in cancer malignant progression. Glioma is classified into multiple subtypes, but lncRNA expression pattern in different subtypes are not fully described. Here, we reported that lncRNA-LINC00941 was highly expressed in all glioma subtypes. Overexpression of lncRNA-LINC00941 in U87 cells promoted cellular proliferation and invasiveness, and suppressed apoptosis. Our findings suggest that lncRNA-LINC00941 may function as an oncogenic factor in glioma, and targeting lncRNA-LINC00941 could be developed into a strategy for glioma management.

Increased expression of TBC1D10B as a potential prognostic and immunotherapy relevant biomarker in liver hepatocellular carcinoma

The TBC1 domain family member 10B (EPI64B/TBC1D10B), a member of the RabGAP EPI64 subfamily, contains a TBC domain that confers GTPase-activating protein activity. Even though overexpression of TBC1D10B has been reported to promote tumor invasion and metastasis in gastric adenocarcinoma, the prognostic value of TBC1D10B and its correlation with DNA methylation and immune infiltration in hepatocellular carcinoma are still not known. Transcriptional expression profiles of TBC1D10B between hepatocellular carcinoma tissues and normal tissues were downloaded from The Cancer Genome Atlas and Gene Expression Omnibus. The Clinical Proteomic Tumor Analysis Consortium and the Human Protein Atlas were used to assess the TBC1D10B protein expression. The biological functions of TBC1D10B were evaluated by the Metascape database and by Gene Set Enrichment Analysis (GSEA). Receiver operating characteristic (ROC) curve analysis was used to distinguish hepatocellular carcinoma from adjacent normal tissues. The effect of TBC1D10B on survival was estimated using the Kaplan-Meier method. DNA methylation in the TBC1D10B gene was assessed using the online MEXPRESS and MethSurv tools. The association between TBC1D10B mRNA expression and immune cell infiltration was investigated by the TIMER2 web server, tumor immune estimation resource and single-sample GSEA. This study found that TBC1D10B is highly expressed in hepatocellular carcinoma and that increased TBC1D10B mRNA expression is associated with female sex, lower Body Mass Index, high level of alpha fetal protein, and worse clinical stages. The mRNA and protein levels of TBC1D10B were verified in cells. Functional annotation indicated enrichment with negative regulation of the cell cycle, extracellular matrix, and corresponding pathways in the high-TBC1D10B phenotype. The ROC curve analysis showed that, with a cutoff level of 2.912, the accuracy, sensitive, and specificity in differentiate TBC1D10B hepatocellular carcinoma from adjacent controls were 0.931, 0.920, and 0.802, respectively. Kaplan-Meier survival analysis showed that hepatocellular carcinoma patients with high TBC1D10B had a worse prognosis than those with low TBC1D10B, especially in patients with a weight below 70 kg, height above 170 cm, and histological G2 and G3. We also found that the methylation of TBC1D10B was associated with the prognosis in patients with hepatocellular carcinoma. Moreover, correlation analysis indicated that TBC1D10B mRNA expression was positively correlated with infiltration levels of most immune cells, but negatively correlated with Th17 and cytotoxic cells infiltration. Our study indicates that increased TBC1D10B expression in hepatocellular carcinoma may play a role in tumorigenesis by regulating the cell cycle and extracellular matrix. TBC1D10B may be a novel prognostic and predictive marker and immune therapeutic target in hepatocellular carcinoma patients.

Clinical features and management issues of NAFLD-related HCC: what we know so far

INTRODUCTION

Nonalcoholic fatty liver disease (NAFLD) is replacing viral hepatitis as the leading cause of chronic liver disease and hepatocellular carcinoma (HCC) in many Western countries. NAFLD-associated HCC usually affects older patients with multiple comorbidities, frequently develops in the absence of cirrhosis, and is often diagnosed later with worse chance of survival. The worse prognosis is also due to limited surveillance strategies and a lower efficacy of standard treatments.

AREAS COVERED

We evaluate the available literature to understand the current surveillance strategies and treatment limitations in the workup of NAFLD-associated HCC, focusing on the differences with HCC associated with other liver diseases.

EXPERT OPINION

In this review we discuss epidemiology and risk factors for HCC in NAFLD patients and address key HCC surveillance and management issues. Although most data are still preliminary, the detection of non-cirrhotic NAFLD patients at increased risk for HCC and the potential adoption of novel screening tools could lead to accurate and suitable HCC surveillance and management strategies for NAFLD patients.

The Implications of Noncoding RNAs in the Evolution and Progression of Nonalcoholic Fatty Liver Disease (NAFLD)-Related HCC

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent liver pathology worldwide. Meanwhile, liver cancer represents the sixth most common malignancy, with hepatocellular carcinoma (HCC) as the primary, most prevalent subtype. Due to the rising incidence of metabolic disorders, NAFLD has become one of the main contributing factors to HCC development. However, although NAFLD might account for about a fourth of HCC cases, there is currently a significant gap in HCC surveillance protocols regarding noncirrhotic NAFLD patients, so the majority of NAFLD-related HCC cases were diagnosed in late stages when survival chances are minimal. However, in the past decade, the focus in cancer genomics has shifted towards the noncoding part of the genome, especially on the microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), which have proved to be involved in the regulation of several malignant processes. This review aims to summarize the current knowledge regarding some of the main dysregulated, noncoding RNAs (ncRNAs) and their implications for NAFLD and HCC development. A central focus of the review is on miRNA and lncRNAs that can influence the progression of NAFLD towards HCC and how they can be used as potential screening tools and future therapeutic targets.

Long noncoding RNA DLEU2 promotes growth and invasion of hepatocellular carcinoma by regulating miR-30a-5p/PTP4A1 axis

Increasing data indicate that long noncoding RNA (lncRNA) DLEU2 is implicated in carcinogenesis in multiple malignancies including hepatocellular carcinoma (HCC). However, the role and molecular mechanism by which lncRNA DLEU2 contributes to HCC remain unknown. The association of lncRNA DLEU2 with clinicopathological characteristics and prognosis in patients with HCC was analyzed by qRT-PCR, and public TCGA dataset. CCK-8, colony formation and Transwell assays were performed to verify the role of lncRNA DLEU2 in HCC. RNA immunoprecipitation (RIP), luciferase gene report and qRT-PCR assays were employed to uncover lncRNA DLEU2-spevific binding with miR-30a-5p. The effect of lncRNA DLEU2 and (or) miR-30a-5p on PTP4A1 expression was examined by Western blot analysis. As a consequence, we found that lncRNA DLEU2 was upregulated in HCC tissue samples and associated with distant metastasis and poor survival in patients with HCC. Knockdown of lncRNA DLEU2 impaired HCC cell proliferation, colony formation and invasion, but ectopic expression of lncRNA DLEU2 abolished these effects. Furthermore, lncRNA DLEU2 harbored a negative correlation and specific binding with miR-30a-5p in HCC cells. Knockdown of lncRNA DLEU2 upregulated miR-30a-5p, but downregulated its target PTP4A1, and miR-30a-5p abrogated lncRNA DLEU2-induced tumor-promoting effects and PTP4A1 upregulation. Taken together, our findings demonstrate that lncRNA DLEU2 promotes growth and invasion of HCC cells by regulating miR-30a-5p/ PTP4A1 axis.

Characterization of differentially expressed and lipid metabolism-related lncRNA-mRNA interaction networks during the growth of liver tissue through rabbit models

Background

Characterization the long non-coding RNAs (lncRNAs) and their regulated mRNAs involved in lipid metabolism during liver growth and development is of great value for discovering new genomic biomarkers and therapeutic targets for fatty liver and metabolic syndrome.

Materials and methods

Liver samples from sixteen rabbit models during the four growth stages (birth, weaning, sexual maturity, and somatic maturity) were used for RNA-seq and subsequent bioinformatics analyses. Differentially expressed (DE) lncRNAs and mRNAs were screened, and the cis/trans-regulation target mRNAs of DE lncRNAs were predicted. Then the function enrichment analyses of target mRNAs were performed through Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, respectively. The target protein interaction (PPI) and lncRNA-mRNA co-expression networks were constructed using string version 11.0 platform and R Stats. Finally, six lncRNAs and six mRNAs were verified taking RT-qPCR.

Results

Liver Oil Red O detection found that the liver showed time-dependent accumulation of lipid droplets. 41,095 lncRNAs, 30,744 mRNAs, and amount to 3,384 DE lncRNAs and 2980 DE mRNAs were identified from 16 cDNA sequencing libraries during the growth of liver. 689 out of all DE lncRNAs corresponded to 440 DE mRNAs by cis-regulation and all DE mRNAs could be regulated by DE lncRNAs by trans-regulation. GO enrichment analysis showed significant enrichment of 892 GO terms, such as protein binding, cytosol, extracellular exsome, nucleoplasm, and oxidation-reduction process. Besides, 52 KEGG pathways were significantly enriched, including 11 pathways of lipid metabolism were found, like Arachidonic acid metabolism, PPAR signaling pathway and Biosynthesis of unsaturated fatty acids. After the low expression DE mRNAs and lncRNAs were excluded, we further obtained the 54 mRNAs were regulated by 249 lncRNAs. 351 interaction pairs were produced among 38 mRNAs and 215 lncRNAs through the co-expression analysis. The PPI network analysis found that 10 mRNAs such as 3β-Hydroxysteroid-Δ24 Reductase (DHCR24), lathosterol 5-desaturase (SC5D), and acetyl-CoA synthetase 2 (ACSS2) were highly interconnected hub protein-coding genes. Except for MSTRG.43041.1, the expression levels of the 11 genes by RT-qPCR were the similar trends to the RNA-seq results.

Conclusion

The study revealed lncRNA-mRNA interation networks that regulate lipid metabolism during liver growth, providing potential research targets for the prophylaxis and treatment of related diseases caused by liver lipid metabolism disorders.

The Functional Mechanism of MicroRNA in Oral Lichen Planus

Non-coding RNAs (ncRNAs) are transcribed from the genomes of mammals and other complex organisms, and many of them are alternately spliced and processed into smaller products. Types of ncRNAs include microRNAs (miRNAs), circular RNAs, and long ncRNAs. miRNAs are about 21 nucleotides long and form a broad class of post-transcriptional regulators of gene expression that affect numerous developmental and physiological processes in eukaryotes. They usually act as negative regulators of mRNA expression through complementary binding sequences in the 3’-UTR of the target mRNA, leading to translation inhibition and target degradation. In recent years, the importance of ncRNA in oral lichen planus (OLP), particularly miRNA, has attracted extensive attention. However, the biological functions of miRNAs and their mechanisms in OLP are still unclear. In this review, we discuss the role and function of miRNAs in OLP, and we also describe their potential functional roles as biomarkers for the diagnosis of OLP. MiRNAs are promising new therapeutic targets, but more work is needed to understand their biological functions.

Noncoding RNA-mediated macrophage and cancer cell crosstalk in hepatocellular carcinoma

The tumor microenvironment (TME) is a well-recognized system that plays an essential role in tumor initiation, development, and progression. Intense intercellular communication between tumor cells and other cells (especially macrophages) occurs in the TME and is mediated by cell-to-cell contact and/or soluble messengers. Emerging evidence indicates that noncoding RNAs (ncRNAs) are critical regulators of the relationship between cells within the TME. In this review, we provide an update on the regulation of ncRNAs (primarily micro RNAs [miRNAs], long ncRNAs [lncRNAs], and circular RNAs [circRNAs]) in the crosstalk between macrophages and tumor cells in hepatocellular carcinoma (HCC). These ncRNAs are derived from macrophages or tumor cells and act as oncogenes or tumor suppressors, contributing to tumor progression not only by regulating the physiological and pathological processes of tumor cells but also by controlling macrophage infiltration, activation, polarization, and function. Herein, we also explore the options available for clinical therapeutic strategies targeting crosstalk-related ncRNAs to treat HCC. A better understanding of the relationship between macrophages and tumor cells mediated by ncRNAs will uncover new diagnostic biomarkers and pharmacological targets in cancer.

Hyaluronan synthase 2, a target of miR-200c, promotes carbon tetrachloride-induced acute and chronic liver inflammation via regulation of CCL3 and CCL4

Liver fibrosis occurs during wound healing after repeated liver injury and is characterized by extensive extracellular matrix deposition. We previously identified hyaluronan synthase 2 (HAS2) as a driver of liver fibrosis and hepatic stellate cell (HSC) activation. Developing strategies to suppress HSC activation is key to alleviating liver fibrosis, and HAS2 is an attractive candidate for intervention. To gain insight into the molecular function of HAS2, we investigated its posttranscriptional regulation. We found that miR-200c directly targets the 3' untranslated regions of HAS2. Moreover, miR-200c and HAS2 were inversely expressed in fibrotic human and mouse livers. After establishing the direct interaction between miR-200c and HAS2, we investigated the functional outcome of regulating HAS2 expression in three murine models: CCl₄-induced acute liver injury, CCl₄-induced chronic liver fibrosis, and bile duct ligation-induced liver fibrosis. Hepatic Has2 expression was induced by acute and chronic CCl₄ treatment. In contrast, miR-200c expression was decreased after CCl₄ treatment. HSC-specific Has2 deletion reduced the expression of inflammatory markers and infiltration of macrophages in the models. Importantly, hyaluronidase-2 (HYAL2) but not HYAL1 was overexpressed in fibrotic human and murine livers. HYAL2 is an enzyme that can cleave the extracellular matrix component hyaluronan. We found that low-molecular-weight hyaluronan stimulated the expression of inflammatory genes. Treatment with the HA synthesis inhibitor 4-methylumbelliferone alleviated bile duct ligation-induced expression of these inflammatory markers. Collectively, our results suggest that HAS2 is negatively regulated by miR-200c and contributes to the development of acute liver injury and chronic liver inflammation via hyaluronan-mediated immune signaling.

The possible role of long non-coding RNAs in recurrent miscarriage

Recurrent miscarriage (RM) is a complicated disease in reproductive medicine that impacts many families. Currently, the etiology of RM is thought to include chromosome abnormalities, reproductive tract malformations, autoimmune dysfunction, infection, and environmental factors. However, the underlying mechanisms of RM remain unknown. At present, research on long non-coding RNAs (lncRNAs) is rapidly emerging and becoming a hot research topic in epigenetic studies. Recent studies revealed that lncRNAs are strongly linked to RM and play a crucial role in epigenetic, cell cycle, cell differentiation regulation, and other life activities. This article mainly reviews the difference in lncRNA expression in patients with RM and regulation of susceptibility, endometrial receptivity, and the maternal-fetal interface. Meanwhile, the correlation between lncRNAs and RM is expounded, which provides new insights for the early diagnosis and treatment of RM.

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.

Long Non-Coding RNAs in Oral Submucous Fibrosis: Their Functional Mechanisms and Recent Research Progress

Many studies have shown that most genomes are transcribed into non-coding RNAs (ncRNAs), including microRNAs (miRs) and long non-coding RNAs (lncRNAs), which can affect different cell characteristics. LncRNAs are long heterologous RNAs that regulate gene expression and various signaling pathways during homeostasis and development. Studies have shown that a lncRNA is an important regulatory molecule that can be targeted to change the physiology and function of cells. Expression or dysfunction of lncRNAs is closely related to various genetic, autoimmune, and metabolic diseases. The importance of ncRNAs in oral submucosal fibrosis (OSF) has garnered much attention in recent years. However, most research has focused on miRs. The role of these molecules in OSF is incompletely understood. This review focuses on the emerging role and function of lncRNAs in OSF as novel regulators. Finally, the potential functional role of lncRNAs as biomarkers for OSF diagnosis is also described. LncRNAs are expected to become a new therapeutic target, but more research is needed to understand their biological functions more deeply.

Long non‑coding RNA ZSCAN16‑AS1 promotes the malignant properties of hepatocellular carcinoma by decoying microRNA‑451a and consequently increasing ATF2 expression

The importance of long noncoding RNAs (lncRNAs) in the oncogenicity of hepatocellular carcinoma (HCC) has been widely studied. However, the detailed functions of ZSCAN16 antisense RNA 1 (ZSCAN16‑AS1) have seldom been explored in HCC until the present study. In the present study, experiments were performed to clarify whether ZSCAN16‑AS1 is implicated in the oncogenesis and progression of HCC and to explore the possible underlying mechanisms. ZSCAN16‑AS1 expression was analyzed using reverse transcription‑quantitative PCR. The effects of ZSCAN16‑AS1 on the biological behavior of HCC cells were demonstrated by functional experiments. The direct binding capacity of ZSCAN16‑AS1 with microRNA‑451a (miR‑451a) was indicated by the luciferase reporter assay and RNA immunoprecipitation. The high expression of ZSCAN16‑AS1 was confirmed in HCC by The Cancer Genome Atlas database and the cohort of the present study. Survival data revealed that patients with a high ZSCAN16‑AS1 level had worse prognosis compared with those with a low ZSCAN16‑AS1 level. Following ZSCAN16‑AS1 knockdown, HCC cell proliferation, migration and invasion were curbed, whereas cell apoptosis was promoted in vitro. The absence of ZSCAN16‑AS1 restricted tumor growth of HCC cells in vivo. Mechanistically, ZSCAN16‑AS1 acted as a competing endogenous RNA by decoying miR‑451a in HCC cells. Furthermore, activating transcription factor 2 (ATF2), a direct target of miR‑451a, was under the regulation of ZSCAN16‑AS1, which was exerted by sequestering miR‑451a. In addition, miR‑451a knockdown or ATF2 resumption reversed the proliferation suppression, apoptosis promotion and migration and invasion inhibition triggered by ZSCAN16‑AS1 silencing. In conclusion, ZSCAN16‑AS1, a pro‑oncogenic lncRNA, aggravated the malignancy of HCC by controlling the miR‑451a/ATF2 axis. An understanding of the competing endogenous RNA network of ZSCAN16‑AS1/miR‑451a/ATF2 in HCC might be instrumental in the development of attractive targets for molecular therapy.

Deciphering the effects of PYCR1 on cell function and its associated mechanism in hepatocellular carcinoma

Overexpression of pyrroline-5-carboxylate reductase 1 (PYCR1) has been associated with the development of certain cancers; however, no studies have specifically examined the role of PYCR1 in hepatocellular carcinoma (HCC). Based on The Cancer Genome Atlas expression array and meta-analysis conducted using the Gene Expression Omnibus database, we determined that PYCR1 was upregulated in HCC compared to adjacent nontumor tissues (P < 0.05). These data were verified using quantitative real-time polymerase chain reaction, western blotting, and immunohistochemistry analysis. Additionally, patients with low PYCR1 expression showed a higher overall survival rate than patients with high PYCR1 expression. Furthermore, PYCR1 overexpression was associated with the female sex, higher levels of alpha-fetoprotein, advanced clinical stages (III and IV), and a younger age (< 45 years old). Silencing of PYCR1 inhibited cell proliferation, invasive migration, epithelial-mesenchymal transition, and metastatic properties in HCC in vitro and in vivo. Using RNA sequencing and bioinformatics tools for data-dependent network analysis, we found binary relationships among PYCR1 and its interacting proteins in defined pathway modules. These findings indicated that PYCR1 played a multifunctional role in coordinating a variety of biological pathways involved in cell communication, cell proliferation and growth, cell migration, a mitogen-activated protein kinase cascade, ion binding, etc. The structural characteristics of key pathway components and PYCR1-interacting proteins were evaluated by molecular docking, and hotspot analysis showed that better affinities between PYCR1 and its interacting molecules were associated with the presence of arginine in the binding site. Finally, a candidate regulatory microRNA, miR-2355-5p, for PYCR1 mRNA was discovered in HCC. Overall, our study suggests that PYCR1 plays a vital role in HCC pathogenesis and may potentially serve as a molecular target for HCC treatment.

Exosomal microRNAs as diagnostic and therapeutic biomarkers in non-malignant liver diseases

The liver is a vital organ responsible for various physiological functions, such as metabolism, immune response, digestion, and detoxification. Crosstalk between hepatocytes, hepatic macrophages, and hepatic stellate cells is critical for liver pathology. Exosomes are small extracellular vesicles (50-150 nm) that play an important role in cell-cell or organ-organ communication as they transfer their cargo, such as protein, DNA, and RNA to recipient cells or distant organs. In various liver diseases, the number of liver cell-derived exosomes is increased and the exosomal microRNA (miRNA) profile is altered. Early studies investigated the value of circulating exosomal miRNAs as biomarkers. Several exosomal miRNAs showed excellent diagnostic values, suggesting their potential as diagnostic biomarkers in liver diseases. Exosomal miRNAs have emerged as critical regulators of liver pathology because they control the expression of multiple genes in recipient cells. In this review, we discuss the biology of exosomes and summarize the recent findings of exosome-mediated intercellular and organ-to-organ communication during liver pathology. As there are many review articles dealing with exosomal miRNAs in liver cancer, we focused on non-malignant liver diseases. The therapeutic potential of exosomal miRNAs in liver pathology is also highlighted.

NAFLD-Associated HCC: Progress and Opportunities

Due to an increase in the obesity-associated metabolic syndrome of epidemic proportions, nonalcoholic fatty liver disease (NAFLD) is becoming a leading cause of hepatocellular carcinoma (HCC) in western countries. This presents added challenges, as NAFLD-associated HCC tends to present at an advanced stage in older patients with co-morbidities. Their prognosis is generally poor with the benefits of standard therapies less certain. The pathogenesis of NAFLD-associated HCC is multifactorial and not well understood, although the risk of HCC developing undoubtedly increases as NAFLD progresses to steatohepatitis and cirrhosis. Recent advances in our understanding of the drivers of NAFLD and HCC will hopefully lead to the development of clinically relevant biomarkers, tools and strategies to aid the identification of high-risk patients, inform preventive measures, and introduction of better tolerated targeted therapies. Lifestyle modification and chemoprevention with drugs such as anti-platelets, statins and anti-diabetics are being evaluated for HCC prevention. The landmark IMBrave150 study introducing the combination of atezolizumab and bevacizumab has recently transformed the landscape of systemic therapies in HCC, with follow-up analyses and real-world data for patients with NAFLD-associated HCC eagerly anticipated. While responses may vary in ways not yet appreciated, the rate of discovery and progress suggests imminent change and opportunities.

LncRNA SNHG16 promotes epithelial-mesenchymal transition by upregulating ITGA6 through miR-488 inhibition in osteosarcoma

BACKGROUND

Osteosarcoma is a primary cause of cancer-associated death in children and adolescents worldwide. Long non-coding RNAs SNHG16 (lncRNA SNHG16) and integrin subunit-a 6 (ITGA6) are recently reported to be involved in the tumorigenesis of osteosarcoma by multiple mechanisms. However, the correlation between SNHG16 and ITGA6 in osteosarcoma remains undetermined.

METHODS

Expression of miR-488, SNHG16 and ITGA6, as well as epithelial-mesenchymal transition (EMT) associated markers in osteosarcoma tissues and cell lines were examined by qRT-PCR or Western blotting. Effects of miR-488, SNHG16 and ITGA6 on cell migration, invasion were evaluated by wound-healing assay and transwell assay. Bioinformatics analysis and dual-luciferase reported assays were applied to assess the interaction among miR-488, SNHG16 and ITGA6. RNA immunoprecipitation (RIP) was also used to verify SNHG16 and miR-488 interaction. Finally, animal study was used to detect the effect of SNHG16 on osteosarcoma in vivo.

RESULTS

SNHG16 and ITGA6 were significantly increased while miR-488 was decreased in osteosarcoma. ITGA6 was screened as a target gene of miR-488, and SNHG16 was sponged by miR-488 in osteosarcoma cells. MiR-488 overexpression and SNHG16 knockdown suppressed migration, invasion and EMT of osteosarcoma cells. Moreover, rescue assays proved that the influences of SNHG16 on osteosarcoma cells migration, invasion and EMT were dependent on miR-488 and ITGA6. In addition, the promotive effects of SNHG16 on osteosarcoma tumor growth and metastasis were further supported by xenograft tumor growth assay.

CONCLUSION

SNHG16 promoted migration, invasion and EMT of osteosarcoma by sponging miR-488 to release ITGA6.

Noncoding RNAs: modulators and modulatable players during infection-induced stress response

The human genome has an almost equal distribution of unique and transposable genetic elements. Although at the transcriptome level, a relatively higher contribution from transposable elements derived RNA has been reported. This is further highlighted with evidence from pervasive transcription. Of the total RNA, noncoding RNAs (ncRNAs) are significant contributors to the transcriptome pool with sizeable fraction from repetitive elements of the human genome, inclusive of Long Interspersed Nuclear Elements (LINEs) and Short Interspersed Nuclear Elements (SINEs). ncRNAs are increasingly being implicated in diverse functional roles especially during conditions of stress. These stress responses are driven through diverse mediators, inclusive of long and short ncRNAs. ncRNAs such as MALAT1, GAS5, miR-204 and miR-199a-5p have been functionally involved during oxidative stress, endoplasmic reticulum (ER) stress and unfolded protein response (UPR). Also, within SINEs, Alu RNAs derived from primate-specific Alu repeats with ~11% human genome contribution, playing a significant role. Pathogenic diseases, including the recent COVID-19, leads to differential regulation of ncRNAs. Although, limited evidence suggests the need for an inquest into the role of ncRNAs in determining the host response towards pathogen challenge.

Liver Cancer: Therapeutic Challenges and the Importance of Experimental Models

Liver cancer is one of the main causes of death related to cancer worldwide; its etiology is related with infections by C or B hepatitis virus, alcohol consumption, smoking, obesity, nonalcoholic fatty liver disease, diabetes, and iron overload, among other causes. Several kinds of primary liver cancer occur, but we will focus on hepatocellular carcinoma (HCC). Numerous cellular signaling pathways are implicated in hepatocarcinogenesis, including YAP-HIPPO, Wnt-β-catenin, and nuclear factor-κB (NF-κB); these in turn are considered novel therapeutic targets. In this review, the role of lipid metabolism regulated by peroxisome proliferator-activated receptor gamma (PPARγ) in the development of HCC will also be discussed. Moreover, recent evidence has been obtained regarding the participation of epigenetic changes such as acetylation and methylation of histones and DNA methylation in the development of HCC. In this review, we provide detailed and current information about these topics. Experimental models represent useful tools for studying the different stages of liver cancer and help to develop new pharmacologic treatments. Each model in vivo and in vitro has several characteristics and advantages to offer for the study of this disease. Finally, the main therapies approved for the treatment of HCC patients, first- and second-line therapies, are described in this review. We also describe a novel option, pirfenidone, which due to its pharmacological properties could be considered in the future as a therapeutic option for HCC treatment.

Role of long non‑coding RNAs and related epigenetic mechanisms in liver fibrosis (Review)

Liver fibrosis is one of the major liver pathologies affecting patients worldwide. It results from an improper tissue repair process following liver injury or inflammation. If left untreated, it ultimately leads to liver cirrhosis and liver failure. Long non‑coding RNAs (lncRNAs) have been implicated in a wide variety of diseases. They can regulate gene expression and modulate signaling. Some of the lncRNAs promote, while others inhibit liver fibrosis. Similarly, other epigenetic processes, such as methylation and acetylation regulate gene transcription and can modulate gene expression. Notably, there are several regulatory associations of lncRNAs with other epigenetic processes. A major mechanism of action of long non‑coding RNAs is to competitively bind to their target microRNAs (miRNAs or miRs), which in turn affects miRNA availability and bioactivity. In the present review, the role of lncRNAs and related epigenetic processes contributing to liver fibrosis is discussed. Finally, various potential therapeutic approaches targeting lncRNAs and related epigenetic processes, which are being considered as possible future treatment targets for liver fibrosis are identified.

Protective effect of lncRNA CRNDE on myocardial cell apoptosis in heart failure by regulating HMGB1 cytoplasm translocation through PARP-1

Long non-coding RNAs (lncRNAs) are bound up with the regulation of various diseases. Here, we probed into the effect of lncRNA colorectal neoplasia differentially expressed (CRNDE) on heart failure (HF). The pathological alterations and cell apoptosis of heart tissues were observed by hematoxylin-eosin and TUNEL staining. The viability or apoptosis of mouse myocardial cells HL-1 was tested by XTT or flow cytometry. The interaction between lncRNA CRNDE and poly-ADP-ribose polymerase 1 (PARP-1) was verified by RNA immunoprecipitation and RNA pull-down. The stability of the PARP-1 protein and the acetylation level of high mobility group box-1 (HMGB1) were determined by cycloheximide-chase and immunoprecipitation, respectively. LncRNA CRNDE expression was decreased in HF mice tissues and doxorubicin (Dox)-treated HL-1 cells, whereas PARP-1 and HMGB1 were increased. The overexpression of lncRNA CRNDE restrained HL-1 cell apoptosis induced by Dox. Moreover, the interaction between CRNDE and PARP-1 was corroborated, CRNDE negatively regulated PARP-1 expression, and the overexpression of CRNDE reduced PARP-1 protein stability. In HL-1 cells, PARP-1 positively regulated the acetylation level and cytoplasm translocation of HMGB1. CRNDE restrained Dox-induced apoptosis in mouse myocardial cells via the PARP-1/HMGB1 pathway.

The prognostic significance of long non-coding RNAs in hepatocellular carcinoma: An updated meta-analysis

BACKGROUND

Recently, many studies have demonstrated that long non-coding RNAs (lncRNAs) are abnormally expressed in hepatocellular carcinoma (HCC) and may serve as a potential molecular biomarker to evaluate the prognosis of hepatocellular carcinoma. Therefore, we accomplished a meta-analysis built on current studies to assess the prognostic value of lncRNAs in hepatocellular carcinoma.

METHODS

The PubMed database was carefully searched to collect all eligible studies until February 20, 2019. The pooled hazard ratios (HRs) and 95% confidence intervals (CIs) of the overall survival, relapse-free survival, and progression-free survival were calculated to evaluate the prognostic significance of lncRNAs expression in hepatocellular carcinoma using Stata12.0 software. Heterogeneity, sensitivity analysis, and publication bias were also evaluated.

RESULTS

The results showed that the expression level of lncRNAs was significantly correlated with clinical outcomes. Abnormally expressed lncRNAs predicted poor overall survival (HR=2.19, 95% CI: 1.99-2.42, P<0.001; I²=44.7%, P=0.005), relapse-free survival (HR=2.68, 95% CI: 1.74-4.14, P<0.001; I²=0.0%, P=0.763) and progression-free survival of hepatocellular carcinoma patients (HR=2.44, 95% CI: 1.53-3.89, P<0.001; I²=0.0%, P=0.336). Statistical significance was also noted in subgroup meta-analyses that were stratified by follow-up time, cutoff value, and quality score. Moreover, the pooled results indicated that lncRNAs expression was significantly associated with tumor size (HR=1.48, 95% CI: 1.24-1.79), tumor number (HR=1.34, 95% CI: 1.08-1.66), and tumor node metastasis stage (HR=2.10, 95% CI: 1.48-2.99), but not liver cirrhosis and tumor differentiation (P>0.05).

CONCLUSIONS

This meta-analysis indicates that lncRNAs are strongly associated with prognosis in hepatocellular carcinoma and may serve as a promising indicator for prognostic evaluation of patients with hepatocellular carcinoma. But larger clinical studies are needed to verify its feasibility.

The AC006262.5-miR-7855-5p-BPY2C axis facilitates hepatocellular carcinoma proliferation and migration

Hepatocellular carcinoma (HCC) is typically fatal, and patients with hepatocellular carcinoma are usually diagnosed at the late stages. Although the treatments for HCC have been rapidly advancing, novel targets for HCC are still desperately needed, especially for targeted therapies. Here, we identified an enriched long non-coding RNA, AC006262.5, associated with HCC, that promoted the proliferation, migration, and invasiveness of HCC cells, both in vitro and in vivo. In addition, our results revealed that AC006262.5 bound to and regulated miR-7855-5p, a tumor-suppressive miRNA, in HCC. Moreover, our data show that AC006262.5 regulates the expression of BPY2C via miR-7855-5p. Finally, we found that AC006262.5 and miR-7855-5p formed a regulatory loop. Upregulation of AC006262.5 resulted in decreased expression of miR-7855-5p, and downregulation of miR-7855-5p further facilitated the expression of AC006262.5. Our work provides novel targets for HCC diagnosis and treatment, and sheds light on the lncRNA-miRNA regulatory nexus that controls the pathology of HCC.

Influence of Genetic Variance on Biomarker Levels After Occupational Exposure to 1,6-Hexamethylene Diisocyanate Monomer and 1,6-Hexamethylene Diisocyanate Isocyanurate

We evaluated the impact of genetic variance on biomarker levels in a population of workers in the automotive repair and refinishing industry who were exposed to respiratory sensitizers 1,6-hexamethylene diisocyanate (HDI) monomer and one of its trimers, HDI isocyanurate. The exposures and respective urine and plasma biomarkers 1,6-diaminohexane (HDA) and trisaminohexyl isocyanurate (TAHI) were measured in 33 workers; and genome-wide microarrays (Affymetrix 6.0) were used to genotype the workers' single-nucleotide polymorphisms (SNPs). Linear mixed model analyses have indicated that interindividual variations in both inhalation and skin exposures influenced these biomarker levels. Using exposure values as covariates and a false discovery rate < 0.10 to assess statistical significance, we observed that seven SNPs were associated with HDA in plasma, five were associated with HDA in urine, none reached significance for TAHI in plasma, and eight were associated with TAHI levels in urine. The different genotypes for the 20 significant SNPs accounted for 4- to 16-fold changes observed in biomarker levels. Associated gene functions include transcription regulation, calcium ion transport, vascular morphogenesis, and transforming growth factor beta signaling pathway, which may impact toxicokinetics indirectly by altering inflammation levels. Additionally, in an expanded analysis using a minor allele cutoff of 0.05 instead of 0.10, there were biomarker-associated SNPs within three genes that have been associated with isocyanate-induced asthma: ALK, DOCK2, and LHPP. We demonstrate that genetic variance impacts the biomarker levels in workers exposed to HDI monomer and HDI isocyanurate and that genetics can be used to refine exposure predictions in small cohorts when quantitative personal exposure and biomarker measurements are included in the models.

Long Noncoding RNAs Coregulated by Annexin A7 and JNK in Hepatocellular Carcinoma Cells Identified by Whole-Genome Expression Profiling

Knockdown of Annexin A7 (ANXA7) or C-Jun N-terminal kinase (JNK) inhibits the proliferation, migration, invasion, and lymphatic adhesion of hepatocellular carcinoma (HCC) cells, suggesting that ANXA7 and JNK signaling pathways contribute to HCC growth and lymph node metastasis (LNM). While the intervening molecular pathways are largely unknown, emerging evidence suggests that long noncoding RNAs (lncRNAs) participate in ANXA7 and JNK signaling. To identify potential therapeutic targets for HCC, we screened for lncRNAs differentially expressed among Hca-P cells stably expressing shRNA-ANXA7, shRNA-JNK, or control-shRNA. RNA sequencing identified 216 lncRNAs differentially expressed between shRNA-ANXA7 and control-shRNA cells, of which 101 were downregulated and 115 upregulated, as well as 436 lncRNAs differentially expressed between shRNA-JNK and control-shRNA cells, of which 236 were downregulated and 200 upregulated. Fifty-six lncRNAs were differentially expressed under both ANXA7 and JNK knockdown. We selected 4 of these for verification based on putative involvement in cancer regulation according to GO and KEEG analyses of target genes. Knockdown of ANXA7 or JNK suppressed expression of NONMMUT012084.2, NONMMUT024756.2, and ENSMUST00000130486, and enhanced expression of ENSMUST00000197932. These lncRNAs are intriguing candidate targets for mechanistic analysis of HCC progression and therapeutic intervention.

LINC00689 participates in proliferation, chemoresistance and metastasis via miR-31-5p/YAP/β-catenin axis in colorectal cancer

As a kind of high-incidence malignant tumors in the digestive tract, colorectal cancer (CRC) has extremely morbidity and mortality in the population. LncRNAs have been proved to regulate the proliferation, chemoresistance and metastasis of tumors including CRC. LINC00689 and miR-31-5p in CRC were found misregulated in CRC by TCGA analysis. However, the mechanism of LINC00689 and miR-31-5p in regulating CRC remains unknown. The expression levels of LINC00689, miR-31-5p and LATS2 in CRC tissues and cell lines were examined by qRT-PCR assay. Cell proliferation, metastasis (including invasion and migration) were quantified by MTT assay, colony formation and Transwell assay, respectively. Western blotting assay was then performed to verify the levels of YAP/β-catenin and metastasis-related proteins. Dual-luciferase reporter assay and RIP assay were performed to evaluate the interaction between LINC00689 (LATS2) and miR-31-5p. Moreover, the function of LINC00689 and miR-31-5p were confirmed by CRC xenograft in nude mice. LINC00689 was decreased while miR-31-5p was increased in CRC. The overexpression of LINC00689 or the knockdown of miR-31-5p inhibited cell proliferation, chemoresistance and metastasis of CRC cells. Meanwhile, the up-regulated LATS2 suppressed the activity of YAP/β-catenin pathway to repress CRC occurrence. Silencing LATS2 reversed the inhibition effects of overexpression of LINC00689 or knockdown of miR-31-5p on proliferation, chemoresistance and metastasis of CRC cells. LINC00689 indeed acted as a miR-31-5p sponge to inhibit CRC proliferation, chemoresistance and metastasis through up-regulating LATS2 and repressing YAP/β-catenin signaling pathway.

Non-coding RNAs and Ischemic Cardiovascular Diseases

The Ischemic Heart Disease (IHD) is considered a clinical condition characterized by myocardial ischemia causing an imbalance between myocardial blood supply and demand, leading to morbidity and mortality across the worldwide. Prompt diagnostic and prognostic represents key factors for the treatment and reduction of the mortality rate. Therefore, one of the newest frontiers in cardiovascular research is related to non-coding RNAs (ncRNAs), which prompted a huge interest in exploring ncRNAs candidates for utilization as potential therapeutic targets for diagnostic and prognostic and/or biomarkers in IHD. However, there are undoubtedly many more functional ncRNAs yet to be discovered and characterized. Here we will discuss our current knowledge and we will provide insight on the roles and effects elicited by some ncRNAs related to IHD.

LncRNAs Act as a Link between Chronic Liver Disease and Hepatocellular Carcinoma

Long non-coding RNAs (lncRNAs) are emerging as important contributors to the biological processes underlying the pathophysiology of various human diseases, including hepatocellular carcinoma (HCC). However, the involvement of these molecules in chronic liver diseases, such as nonalcoholic fatty liver disease (NAFLD) and viral hepatitis, has only recently been considered in scientific research. While extensive studies on the pathogenesis of the development of HCC from hepatic fibrosis have been conducted, their regulatory molecular mechanisms are still only partially understood. The underlying mechanisms related to lncRNAs leading to HCC from chronic liver diseases and cirrhosis have not yet been entirely elucidated. Therefore, elucidating the functional roles of lncRNAs in chronic liver disease and HCC can contribute to a better understanding of the molecular mechanisms, and may help in developing novel diagnostic biomarkers and therapeutic targets for HCC, as well as in preventing the progression of chronic liver disease to HCC. Here, we comprehensively review and briefly summarize some lncRNAs that participate in both hepatic fibrosis and HCC.

The Roles and Mechanisms of lncRNAs in Liver Fibrosis

Many studies have revealed that circulating long noncoding RNAs (lncRNAs) regulate gene and protein expression in the process of hepatic fibrosis. Liver fibrosis is a reversible wound healing response followed by excessive extracellular matrix accumulation. In the development of liver fibrosis, some lncRNAs regulate diverse cellular processes by acting as competing endogenous RNAs (ceRNAs) and binding proteins. Previous investigations demonstrated that overexpression of lncRNAs such as H19, maternally expressed gene 3 (MEG3), growth arrest-specific transcript 5 (GAS5), Gm5091, NR_002155.1, and HIF 1alpha-antisense RNA 1 (HIF1A-AS1) can inhibit the progression of liver fibrosis. Furthermore, the upregulation of several lncRNAs [e.g., nuclear paraspeckle assembly transcript 1 (NEAT1), hox transcript antisense RNA (Hotair), and liver-enriched fibrosis-associated lncRNA1 (lnc-LFAR1)] has been reported to promote liver fibrosis. This review will focus on the functions and mechanisms of lncRNAs, the lncRNA transcriptome profile of liver fibrosis, and the main lncRNAs involved in the signalling pathways that regulate hepatic fibrosis. This review provides insight into the screening of therapeutic and diagnostic markers of liver fibrosis.

Can small nucleolar RNA be a novel molecular target for hepatocellular carcinoma?

BACKGROUND

Globally, hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death. Recently, many studies have demonstrated that small nucleolar RNA (snoRNA) was closely related to HCC.

OBJECTIVE

To explore whether snoRNA can be used as a molecular target for HCC.

METHODS

The PubMed, Embase, and Cochrane databases were searched for the published literatures related to snoRNA and HCC until August 12, 2019. After identification, screening, and verification, this study finally included 26 studies correlating small nucleolar RNA host gene (SNHG) and HCC, and 8 studies correlating snoRNA and HCC. Based on the collation of the relevant literature, the correlation network diagram between snoRNAs and HCC was constructed.

RESULTS

The SNHGs, such as SNHG1, SNHG6, SNHG16, and SNHG20 can play varied roles in HCC through different regulatory mechanisms. These SNHGs can promote and inhibit tumorigenesis. SNORD76 can promote the proliferation of tumor tissues and cells in vitro through different pathways. SnoU2_19 and SNORD76 can function through the same pathway. SNHG3, SNHG20, SNHG6, SNORD76, and snoRA47 can modulate epithelial-mesenchymal transition (EMT) to regulate the development of HCC cell or tissue. SNHG16, SNORD76, and SnoU2_19 can regulate the development of HCC through Wnt/β-catenin signaling pathway.

CONCLUSION

snoRNA can regulate the occurrence of HCC by modulating multiple molecular signaling pathways. Hence, snoRNA can be a potential molecular target for HCC.

Role of MicroRNA in the Diagnosis and Management of Hepatocellular Carcinoma

INTRODUCTION

Hepatocellular Carcinoma (HCC) is one of the most common malignant tumors in the world and comes third in cancer-induced mortality. The need for improved and more specific diagnostic methods that can detect early-stage disease is immense, as it is amenable to curative modalities, while advanced HCC is associated with low survival rates. microRNA (miRNA) expression is deregulated in HCC and this can be implemented both diagnostically and therapeutically.

OBJECTIVE

To provide a concise review on the role of miRNA in diagnosis, prognosis, and treatment of HCC.

METHODS

We conducted a comprehensive review of the PubMed bibliographic database.

RESULTS

Multiple miRNAs are involved in the pathogenesis of HCC. Measurement of the levels of these miRNAs either in tumor tissue or in the blood constitutes a promising diagnostic, as well as prognostic tool. OncomiRs are miRNAs that promote tumorigenesis, thus inhibiting them by administering antagomiRs is a promising treatment option. Moreover, replacement of the depleted miRNAs is another potential therapeutic approach for HCC. Modification of miRNA levels may also regulate sensitivity to chemotherapeutic agents.

CONCLUSION

miRNA play a pivotal role in HCC pathogenesis and once the underlying mechanisms are elucidated, they will become part of everyday clinical practice against HCC.

Identification Of Novel lncRNAs For Detection Of HBV-Associated Hepatocellular Carcinoma

Purpose

This study was conducted to investigate the differentially expressed profiles of long non-coding RNAs (lncRNAs) in HBV-associated HCC (HBV-HCC), which may serve as potential diagnostic biomarkers and therapeutic targets.

Methods

To examine the differentially expressed profiles of lncRNAs and mRNAs using microarray analysis, we collected 15 specimens: five HBV-associated HCC tissues, five paired adjacent peritumoral liver tissues (APLT), and five distant peritumoral liver tissues (DPLT). Then, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to predict the biological roles and potential signaling pathways of these dysregulated mRNAs. In addition, lncRNA-mRNA co-expression network and signal transduction pathway network (Signal-net) were employed to further explore the potential target genes and roles of dysregulated lncRNAs in HBV-HCC pathogenesis. Finally, quantitative real-time PCR (qRT-PCR) was used to confirm the expression of six selected dysregulated lncRNAs.

Results

A total number of 719 lncRNAs and 3438 mRNAs were significantly more dysregulated in HBV-HCC tissues than in APLT and DPLT (fold change > 2, P < 0.05, FDR < 0.05). Additionally, 337 GO terms and 53 KEGG pathways were established to be significantly enriched. These dysregulated mRNAs were mainly enriched in metabolism-related biological processes. Additionally, lncRNA-mRNA coexpression network analysis showed that NONHSAT053785 is at the core of the network. Furthermore, the Signal-net analysis showed that CYP3A4 was gene with the highest degree. Finally, the data of five of the six selected differentially expressed lncRNAs were in agreement with the microarray data obtained by qRT-PCR verification.

Conclusion

Our study revealed the differentially expressed profiles of lncRNAs and mRNAs for HBV-HCC, and five novel dysregulated lncRNAs were identified in HBV-HCC tissues. The aforementioned dysregulated lncRNAs may represent potential diagnostic biomarkers and therapeutic targets of HBV-HCC, which needs to be validated in future studies.

Circular RNA expression and circPTPRM promotes proliferation and migration in hepatocellular carcinoma

Circular RNAs (circRNAs) play a critical role during hepatocellular carcinoma (HCC) development. CircRNA PTPRM (circPTPRM) has not been reported to cause disease and its role in HCC is unclear. This study explored circRNA expression and the function of circPTPRM in HCC. RNA sequencing (RNA-seq) was performed on 3 randomly selected pairs of HCC tissues and their corresponding adjacent non-tumor tissues. Three differentially expressed circRNAs, circPTPRM, circSMAD2 and circPTBP3 were selected and verified by real-time quantitative reverse transcription-polymerase chain reactions in 30 pairs of tissue samples, In vitro cultured hepatoma cells, and normal liver cells. Clinical data analysis was performed to select target circRNAs. Anti-target circRNA siRNAs were transfected into hepatoma cell lines, and the biological behavior of hepatoma cells following silencing of the target circRNA were detected by cell proliferation, plate cloning, and transwell assays. There were 86 differentially expressed circRNAs from RNA-seq, of which 53 were significantly upregulated and 33 were significantly downregulated in HCC. CircPTPRM expression was significantly upregulated in HCC tissue (p = 0.023) based on the analysis of 30 paired samples. CircPTPRM expression positively correlated with HCC recurrence and metastasis (p = 0.039). CircPTPRM silencing reduced HCC cell proliferation, migration and invasion. CircRNAs were differentially expressed in HCC samples. CircPTPRM was significantly upregulated in HCC and may function during the tumorigenesis and metastasis of HCC.