An expanded landscape of human long noncoding RNA

Long non-coding RNA variability in porcine skeletal muscle

Recently, numerous studies including various tissues have been carried out on long non-coding RNAs (lncRNAs), but still, its variability has not yet been fully understood. In this study, we characterised the inter-individual variability of lncRNAs in pigs, in the context of number, length and expression. Transcriptomes collected from muscle tissue belonging to six Polish Landrace boars (PL1-PL6), including half-brothers (PL1-PL3), were investigated using bioinformatics (lncRNA identification and functional analysis) and statistical (lncRNA variability) methods. The number of lncRNA ranged from 1289 to 3500 per animal, and the total number of common lncRNAs among all boars was 232. The number, length and expression of lncRNAs significantly varied between individuals, and no consistent pattern has been found between pairs of half-brothers. In detail, PL5 exhibits lower expression than the others, while PL4 has significantly higher expression than PL2-PL3 and PL5-PL6. Noteworthy, comparing the inter-individual variability of lncRNA and mRNA expression, they exhibited concordant patterns. The enrichment analysis for common lncRNA target genes determined a variety of biological processes that play fundamental roles in cell biology, and they were mostly related to whole-body homeostasis maintenance, energy and protein synthesis as well as dynamics of multiple nucleoprotein complexes. The high variability of lncRNA landscape in the porcine genome has been revealed in this study. The inter-individual differences have been found in the context of three aspects: the number, length and expression of lncRNAs, which contribute to a better understanding of its complex nature.

Research on the mechanism of exosomes from different sources influencing the progression of lung cancer

As a key regulator of intercellular communication, exosomes are essential for tumor cells. In our study, we will explore the mechanisms of exosomes from different sources on lung cancer. We isolated CD8+T cells and cancer-associated fibroblasts (CAFs) from venous blood and tumor tissues of lung cancer patients, and isolated exosomes. MiR-2682 was high expression in CD8+T-derived exosomes, and lncRNA-FOXD3-AS1 was upregulated in CAF-derived exosomes. Online bioinformatics database analysis showed that RNA Binding Motif Protein 39 (RBM39) was identified as the target of miR-2682, and eukaryotic translation initiation factors 3B (EIF3B) was identified as the RNA binding protein of FOXD3-AS1. CD8+T-derived exosomes inhibited the growth of A549 cells and promoted apoptosis, while miR-2682 inhibits reversed these effects of CD8+T-derived exosomes. CAF-derived exosomes promoted the growth of A549 cells and inhibited apoptosis, while FOXD3-AS1 siRNA reversed the effect of CAF-derived exosomes. Mechanism studies have found that miR-2682 inhibits the growth of lung cancer cells by inhibiting the expression of RBM39. FOXD3-AS1 promoted the growth of lung cancer cells by binding to EIF3B. In vivo experiments showed that CD8+T cell-derived exosome miR-2682 inhibited lung cancer tumor formation, while CAF-derived exosome FOXD3-AS1 promoted lung cancer tumor formation. This study provides mechanistic insights into the role of miR-2682 and FOXD3-AS1 in lung cancer progression and provides new strategies for lung cancer treatment.

An emerging link between lncRNAs and cancer sex dimorphism

The prevalence and progression of cancer differ in males and females, and thus, sexual dimorphism in tumor development directly impacts clinical research and medicine. Long non-coding RNAs (lncRNAs) are increasingly recognized as important players in gene expression and various cellular processes, including cancer development and progression. In recent years, lncRNAs have been implicated in the differences observed in cancer incidence, progression, and treatment responses between men and women. Here, we present a brief overview of the current knowledge regarding the role of lncRNAs in cancer sex dimorphism, focusing on how they affect epigenetic processes in male and female mammalian cells. We discuss the potential mechanisms by which lncRNAs may contribute to sex differences in cancer, including transcriptional control of sex chromosomes, hormonal signaling pathways, and immune responses. We also propose strategies for studying lncRNA functions in cancer sex dimorphism. Furthermore, we emphasize the importance of considering sex as a biological variable in cancer research and the need to investigate the role lncRNAs play in mediating these sex differences. In summary, we highlight the emerging link between lncRNAs and cancer sex dimorphism and their potential as therapeutic targets.

Cervical cancer-specific long non-coding RNA landscape reveals the favorable prognosis predictive performance of an ion-channel-related signature model

BACKGROUND

Ion channels play an important role in tumorigenesis and progression of cervical cancer. Multiple long non-coding RNA genes are widely involved in ion channel-related signaling regulation. However, the association and potential clinical application of lncRNAs in the prognosis of cervical cancer are still poorly explored.

METHODS

Thirteen patients with cervical cancer were enrolled in current study. Whole transcriptome (involving both mRNAs and lncRNAs) sequencing was performed on fresh tumor and adjacent normal tissues that were surgically resected from patients. A comprehensive cervical cancer-specific lncRNA landscape was obtained by our custom pipeline. Then, a prognostic scoring model of ion-channel-related lncRNAs was established by regression algorithms. The performance of the predictive model as well as its association with the clinical characteristics and tumor microenvironment (TME) status were further evaluated.

RESULTS

To comprehensively identify cervical cancer-specific lncRNAs, we sequenced 26 samples of cervical cancer patients and integrated the transcriptomic results. We built a custom analysis pipeline to improve the accuracy of lncRNA identification and functional annotation and obtained 18,482 novel lncRNAs in cervical cancer. Then, 159 ion channel- and tumorigenesis-related (ICTR-) lncRNAs were identified. Based on nine ICTR-lncRNAs, we also established a prognostic scoring model and validated its accuracy and robustness in assessing the prognosis of patients with cervical cancer. Besides, the TME was characterized, and we found that B cells, activated CD8+ T, and tertiary lymphoid structures were significantly associated with ICTR-lncRNAs signature scores.

CONCLUSION

We provided a thorough landscape of cervical cancer-specific lncRNAs. Through integrative analyses, we identified ion-channel-related lncRNAs and established a predictive model for assessing the prognosis of patients with cervical cancer. Meanwhile, we characterized its association with TME status. This study improved our knowledge of the prominent roles of lncRNAs in regulating ion channel in cervical cancer.

Enriched atlas of lncRNA and protein-coding genes for the GRCg7b chicken assembly and its functional annotation across 47 tissues

Gene atlases for livestock are steadily improving thanks to new genome assemblies and new expression data improving the gene annotation. However, gene content varies across databases due to differences in RNA sequencing data and bioinformatics pipelines, especially for long non-coding RNAs (lncRNAs) which have higher tissue and developmental specificity and are harder to consistently identify compared to protein coding genes (PCGs). As done previously in 2020 for chicken assemblies galgal5 and GRCg6a, we provide a new gene atlas, lncRNA-enriched, for the latest GRCg7b chicken assembly, integrating "NCBI RefSeq", "EMBL-EBI Ensembl/GENCODE" reference annotations and other resources such as FAANG and NONCODE. As a result, the number of PCGs increases from 18,022 (RefSeq) and 17,007 (Ensembl) to 24,102, and that of lncRNAs from 5789 (RefSeq) and 11,944 (Ensembl) to 44,428. Using 1400 public RNA-seq transcriptome representing 47 tissues, we provided expression evidence for 35,257 (79%) lncRNAs and 22,468 (93%) PCGs, supporting the relevance of this atlas. Further characterization including tissue-specificity, sex-differential expression and gene configurations are provided. We also identified conserved miRNA-hosting genes with human counterparts, suggesting common function. The annotated atlas is available at gega.sigenae.org.

Long Noncoding RNA GAS5-Involved Progression of Neonatal Hydrocephalus and Inflammatory Responses

Intraventricular hemorrhage results in posthemorrhagic hydrocephalus (PHH). Neonatal hydrocephalus remains a challenging disease due to the high failure rate of all management strategies. We evaluated long noncoding RNA growth arrest-specific 5 (GAS5)-mediated network in neonatal hydrocephalus, providing a new direction for the treatment of hydrocephalus. The PHH model was constructed in neonatal rats after intracerebroventricular injection with GAS5, miR-325-3p, and chaperonin containing T-complex protein 1, subunit 8 (CCT8) plasmids, or oligonucleotides. Next, behavioral tests, measurement of serum inflammation, observation of brain tissue pathology, and calculation of hemoglobin and brain water contents were implemented. GAS5, miR-325-3p, and CCT8 expression, in combination with their interactions, was checked. As the results reported, collagenase infusion induced hydrocephalus, impairing neurological function, enhancing inflammation and neuronal apoptosis, and increasing hemoglobin and brain water contents. GAS5 and CCT8 were up-regulated, while miR-325-3p was down-regulated in hydrocephalic rats. Downregulating GAS5/CCT8 or upregulating miR-325-3p could inhibit inflammatory response and improve neurological function in young hydrocephalic rats. GAS5 promotes CCT8 expression through sponge adsorption of miR-325-3p. GAS5 silencing-mediated protections against hydrocephalus were counteracted by CCT8 overexpression. In summary, GAS5 aggravates neonatal hydrocephalus and inflammatory responses in a way of leasing miR-325-3p-involved regulation of CCT8.

New Insights on NLRP3 Inflammasome: Mechanisms of Activation, Inhibition, and Epigenetic Regulation

Inflammasomes are important modulators of inflammation. Dysregulation of inflammasomes can enhance vulnerability to conditions such as neurodegenerative diseases, autoinflammatory diseases, and metabolic disorders. Among various inflammasomes, Nucleotide-binding oligomerization domain leucine-rich repeat and pyrin domain-containing protein 3 (NLRP3) is the best-characterized inflammasome related to inflammatory and neurodegenerative diseases. NLRP3 is an intracellular sensor that recognizes pathogen-associated molecular patterns and damage-associated patterns resulting in the assembly and activation of NLRP3 inflammasome. The NLRP3 inflammasome includes sensor NLRP3, adaptor apoptosis-associated speck-like protein (ASC), and effector cysteine protease procaspase-1 that plays an imperative role in caspase-1 stimulation which further initiates a secondary inflammatory response. Regulation of NLRP3 inflammasome ameliorates NLRP3-mediated diseases. Much effort has been invested in studying the activation, and exploration of specific inhibitors and epigenetic mechanisms controlling NLRP3 inflammasome. This review gives an overview of the established NLRP3 inflammasome assembly, its brief molecular mechanistic activations as well as a current update on specific and non-specific NLRP3 inhibitors that could be used in NLRP3-mediated diseases. We also focused on the recently discovered epigenetic mechanisms mediated by DNA methylation, histone alterations, and microRNAs in regulating the activation and expression of NLRP3 inflammasome, which has resulted in a novel method of gaining insight into the mechanisms that modulate NLRP3 inflammasome activity and introducing potential therapeutic strategies for CNS disorders.

The Impact of Alcohol-Induced Epigenetic Modifications in the Treatment of Alcohol use Disorders

Alcohol use disorders are responsible for 5.9% of all death annually and 5.1% of the global disease burden. It has been suggested that alcohol abuse can modify gene expression through epigenetic processes, namely DNA and histone methylation, histone acetylation, and microRNA expression. The alcohol influence on epigenetic mechanisms leads to molecular adaptation of a wide number of brain circuits, including the hypothalamus-hypophysis-adrenal axis, the prefrontal cortex, the mesolimbic-dopamine pathways and the endogenous opioid pathways. Epigenetic regulation represents an important level of alcohol-induced molecular adaptation in the brain. It has been demonstrated that acute and chronic alcohol exposure can induce opposite modifications in epigenetic mechanisms: acute alcohol exposure increases histone acetylation, decreases histone methylation and inhibits DNA methyltransferase activity, while chronic alcohol exposure induces hypermethylation of DNA. Some studies investigated the chromatin status during the withdrawal period and the craving period and showed that craving was associated with low methylation status, while the withdrawal period was associated with elevated activity of histone deacetylase and decreased histone acetylation. Given the effects exerted by ethanol consumption on epigenetic mechanisms, chromatin structure modifiers, such as histone deacetylase inhibitors and DNA methyltransferase inhibitors, might represent a new potential strategy to treat alcohol use disorder. Further investigations on molecular modifications induced by ethanol might be helpful to develop new therapies for alcoholism and drug addiction targeting epigenetic processes.

LncRNA-mediated Modulation of Endothelial Cells: Novel Progress in the Pathogenesis of Coronary Atherosclerotic Disease

Coronary atherosclerotic disease (CAD) is a common cardiovascular disease and an important cause of death. Moreover, endothelial cells (ECs) injury is an early pathophysiological feature of CAD, and long noncoding RNAs (lncRNAs) can modulate gene expression. Recent studies have shown that lncRNAs are involved in the pathogenesis of CAD, especially by regulating ECs. In this review, we summarize the novel progress of lncRNA-modulated ECs in the pathogenesis of CAD, including ECs proliferation, migration, adhesion, angiogenesis, inflammation, apoptosis, autophagy, and pyroptosis. Thus, as lncRNAs regulate ECs in CAD, lncRNAs will provide ideal and novel targets for the diagnosis and drug therapy of CAD.

Comprehensive Analysis of Disulfidptosis-Related LncRNAs in Molecular Classification, Immune Microenvironment Characterization and Prognosis of Gastric Cancer

BACKGROUND

Disulfidptosis is a novel form of programmed cell death that unveils promising avenues for the exploration of tumor treatment modalities. Gastric cancer (GC) is a malignant tumor characterized by high incidence and mortality rate. However, there has been no systematic study of disulfidptosis-related long noncoding RNAs (DRLs) signature in GC patients.

METHODS

The lncRNA expression profiles containing 412 GC samples were acquired from the Cancer Genome Atlas (TCGA) database. Differential expression analysis was performed alongside Pearson correlation analysis to identify DRLs. Prognostically significant DRLs were further screened using univariate COX regression analysis. Subsequently, LASSO regression and multifactorial COX regression analyses were employed to establish a risk signature composed of DRLs that exhibit independent prognostic significance. The predictive value of this risk signature was further validated in a test cohort. The ESTIMATE, CIBERSORT and ssGSEA methodologies were utilized to investigate the tumor immune microenvironment of GC populations with different DRLs profiles. Finally, the correlation between DRLs and various GC drug responses was explored.

RESULTS

We established a prognostic signature comprising 12 disulfidptosis-related lncRNAs (AC110491.1, AL355574.1, RHPN1-AS1, AOAH-IT1, AP001065.3, MEF2C-AS1, AC016394.2, LINC00705, LINC01952, PART1, TNFRSF10A-AS1, LINC01537). The Kaplan-Meier survival analysis revealed that patients in the high-risk group exhibited a poor prognosis. Both univariate and multivariate COX regression models demonstrated that the DRLs signature was an independent prognostic indicator in GC patients. Furthermore, the signature exhibited accurate predictions of survival at 1-, 3- and 5- years with the area under the curve (AUC) values of 0.708, 0.689 and 0.854, respectively. In addition, we also observed significant associations between the DRLs signature and various clinical variables, distinct immune landscape and drug sensitivity profiles in GC patients. The low-risk group patients may be more likely to benefit from immunotherapy and chemotherapy.

CONCLUSIONS

Our study investigated the role and potential clinical implications of DRLs in GC. The risk model constructed by DRLs demonstrated high accuracy in predicting the survival outcomes of GC and improving the treatment efficacy for GC patients.

Long non-coding RNA LHX1-DT regulates cardiomyocyte differentiation through H2A.Z-mediated LHX1 transcriptional activation

Long non-coding RNAs (lncRNAs) play widespread roles in various processes. However, there is still limited understanding of the precise mechanisms through which they regulate early stage cardiomyocyte differentiation. In this study, we identified a specific lncRNA called LHX1-DT, which is transcribed from a bidirectional promoter of LIM Homeobox 1 (LHX1) gene. Our findings demonstrated that LHX1-DT is nuclear-localized and transiently elevated expression along with LHX1 during early differentiation of cardiomyocytes. The phenotype was rescued by overexpression of LHX1 into the LHX1-DT-/- hESCs, indicating LHX1 is the downstream of LHX1-DT. Mechanistically, we discovered that LHX1-DT physically interacted with RNA/histone-binding protein PHF6 during mesoderm commitment and efficiently replaced conventional histone H2A with a histone variant H2A.Z at the promoter region of LHX1. In summary, our work uncovers a novel lncRNA, LHX1-DT, which plays a vital role in mediating the exchange of histone variants H2A.Z and H2A at the promoter region of LHX1.

Long noncoding RNA study: Genome-wide approaches

Long noncoding RNAs (lncRNAs) have been confirmed to play a crucial role in various biological processes across several species. Though many efforts have been devoted to the expansion of the lncRNAs landscape, much about lncRNAs is still unknown due to their great complexity. The development of high-throughput technologies and the constantly improved bioinformatic methods have resulted in a rapid expansion of lncRNA research and relevant databases. In this review, we introduced genome-wide research of lncRNAs in three parts: (i) novel lncRNA identification by high-throughput sequencing and computational pipelines; (ii) functional characterization of lncRNAs by expression atlas profiling, genome-scale screening, and the research of cancer-related lncRNAs; (iii) mechanism research by large-scale experimental technologies and computational analysis. Besides, primary experimental methods and bioinformatic pipelines related to these three parts are summarized. This review aimed to provide a comprehensive and systemic overview of lncRNA genome-wide research strategies and indicate a genome-wide lncRNA research system.

Global mapping of RNA-chromatin contacts reveals a proximity-dominated connectivity model for ncRNA-gene interactions

Non-coding RNAs (ncRNAs) are transcribed throughout the genome and provide regulatory inputs to gene expression through their interaction with chromatin. Yet, the genomic targets and functions of most ncRNAs are unknown. Here we use chromatin-associated RNA sequencing (ChAR-seq) to map the global network of ncRNA interactions with chromatin in human embryonic stem cells and the dynamic changes in interactions during differentiation into definitive endoderm. We uncover general principles governing the organization of the RNA-chromatin interactome, demonstrating that nearly all ncRNAs exclusively interact with genes in close three-dimensional proximity to their locus and provide a model predicting the interactome. We uncover RNAs that interact with many loci across the genome and unveil thousands of unannotated RNAs that dynamically interact with chromatin. By relating the dynamics of the interactome to changes in gene expression, we demonstrate that activation or repression of individual genes is unlikely to be controlled by a single ncRNA.

Comprehensive transcriptomic analysis of long non-coding RNAs in bovine ovarian follicles and early embryos

Long non-coding RNAs (lncRNAs) have been the subject of numerous studies over the past decade. First thought to come from aberrant transcriptional events, lncRNAs are now considered a crucial component of the genome with roles in multiple cellular functions. However, the functional annotation and characterization of bovine lncRNAs during early development remain limited. In this comprehensive analysis, we review lncRNAs expression in bovine ovarian follicles and early embryos, based on a unique database comprising 468 microarray hybridizations from a single platform designed to target 7,724 lncRNA transcripts, of which 5,272 are intergenic (lincRNA), 958 are intronic, and 1,524 are antisense (lncNAT). Compared to translated mRNA, lncRNAs have been shown to be more tissue-specific and expressed in low copy numbers. This analysis revealed that protein-coding genes and lncRNAs are both expressed more in oocytes. Differences between the oocyte and the 2-cell embryo are also more apparent in terms of lncRNAs than mRNAs. Co-expression network analysis using WGCNA generated 25 modules with differing proportions of lncRNAs. The modules exhibiting a higher proportion of lncRNAs were found to be associated with fewer annotated mRNAs and housekeeping functions. Functional annotation of co-expressed mRNAs allowed attribution of lncRNAs to a wide array of key cellular events such as meiosis, translation initiation, immune response, and mitochondrial related functions. We thus provide evidence that lncRNAs play diverse physiological roles that are tissue-specific and associated with key cellular functions alongside mRNAs in bovine ovarian follicles and early embryos. This contributes to add lncRNAs as active molecules in the complex regulatory networks driving folliculogenesis, oogenesis and early embryogenesis all of which are necessary for reproductive success.

AP003352.1/miR-141-3p axis enhances the proliferation of osteosarcoma by LPAR3

Osteosarcoma (OS) is a highly malignant tumor with a poor prognosis and a growing incidence. LncRNAs and microRNAs control the occurrence and development process of osteosarcoma through ceRNA patterns. The LPAR3 gene is important in cancer cell proliferation, apoptosis and disease development. However, the regulatory mechanism of the ceRNA network through which LPAR3 participates in osteosarcoma has not been clarified. Herein, our study demonstrated that the AP003352.1/miR-141-3p axis drives LPAR3 expression to induce the malignant progression of osteosarcoma. First, the expression of LPAR3 is regulated by the changes in AP003352.1 and miR-141-3p. Similar to the ceRNA of miR-141-3p, AP003352.1 regulates the expression of LPAR3 through this mechanism. In addition, the regulation of AP003352.1 in malignant osteosarcoma progression depends to a certain degree on miR-141-3p. Importantly, the AP003352.1/miR-141-3p/LPAR3 axis can better serve as a multi-gene diagnostic marker for osteosarcoma. In conclusion, our research reveals a new ceRNA regulatory network, which provides a novel potential target for the diagnosis and treatment of osteosarcoma.

Clinical Importance of the lncRNA NEAT1 in Cancer Patients Treated with Immune Checkpoint Inhibitors

PURPOSE

mAbs targeting the PD-1/PD-L1 immune checkpoint are powerful tools to improve the survival of patients with cancer. Understanding the molecular basis of clinical response to these treatments is critical to identify patients who can benefit from this immunotherapy. In this study, we investigated long noncoding RNA (lncRNA) expression in patients with cancer treated with anti-PD-1/PD-L1 immunotherapy.

EXPERIMENTAL DESIGN

lncRNA expression profile was analyzed in one cohort of patients with melanoma and two independent cohorts of patients with glioblastoma (GBM) undergoing anti-PD-1/PD-L1 immunotherapy. Single-cell RNA-sequencing analyses were performed to evaluate lncRNA expression in tumor cells and tumor-infiltrating immune cells.

RESULTS

We identified the lncRNA NEAT1 as commonly upregulated between patients with melanoma with complete therapeutic response and patients with GBM with longer survival following anti-PD-1/PD-L1 treatment. Gene set enrichment analyses revealed that NEAT1 expression was strongly associated with the IFNγ pathways, along with downregulation of cell-cycle-related genes. Single-cell RNA-sequencing analyses revealed NEAT1 expression across multiple cell types within the GBM microenvironment, including tumor cells, macrophages, and T cells. High NEAT1 expression levels in tumor cells correlated with increased infiltrating macrophages and microglia. In these tumor-infiltrating myeloid cells, we found that NEAT1 expression was linked to enrichment in TNFα/NFκB signaling pathway genes. Silencing NEAT1 suppressed M1 macrophage polarization and reduced the expression of TNFα and other inflammatory cytokines.

CONCLUSIONS

These findings suggest an association between NEAT1 expression and patient response to anti-PD-1/PD-L1 therapy in melanoma and GBM and have important implications for the role of lncRNAs in the tumor microenvironment.

Long noncoding RNA signatures in intrauterine infection/inflammation-induced lung injury: an integrative bioinformatics study

BACKGROUND

Intrauterine infection/inflammation can result in fetal and neonatal lung injury. However, the biological mechanisms of intrauterine infection/inflammation on fetal and neonatal lung injury and development are poorly known. To date, there are no reliable biomarkers for improving intrauterine infection/inflammation-induced lung injury.

METHODS

An animal model of intrauterine infection/inflammation-induced lung injury was established with pregnant Sprague-Dawley rats inoculated with Escherichia coli suspension. The intrauterine inflammatory status was assessed through the histological examination of the placenta and uterus. A serial of histological examinations of the fetal and neonatal rats lung tissues were performed. The fetal and neonatal rat lung tissues were harvested for next generation sequencing at embryonic day 17 and postnatal day 3, respectively. Differentially expressed mRNAs and lncRNAs were identified by conducting high-throughput sequencing technique. The target genes of identified differentially expressed lncRNAs were analyzed. Homology analyses for important differentially expressed lncRNAs were performed.

RESULTS

The histopathological results showed inflammatory infiltration, impaired alveolar vesicular structure, less alveolar numbers, and thickened alveolar septa in fetal and neonatal rat lung tissues. Transmission electron micrographs revealed inflammatory cellular swelling associated with diffuse alveolar damage and less surfactant-storing lamellar bodies in alveolar epithelial type II cells. As compared with the control group, there were 432 differentially expressed lncRNAs at embryonic day 17 and 125 differentially expressed lncRNAs at postnatal day 3 in the intrauterine infection group. The distribution, expression level, and function of these lncRNAs were shown in the rat genome. LncRNA TCONS_00009865, lncRNA TCONS_00030049, lncRNA TCONS_00081686, lncRNA TCONS_00091647, lncRNA TCONS_00175309, lncRNA TCONS_00255085, lncRNA TCONS_00277162, and lncRNA TCONS_00157962 may play an important role in intrauterine infection/inflammation-induced lung injury. Fifty homologous sequences in Homo sapiens were also identified.

CONCLUSIONS

This study provides genome-wide identification of novel lncRNAs which may serve as potential diagnostic biomarkers and therapeutic targets for intrauterine infection/inflammation-induced lung injury.

The Clinical Utility of lncRNAs and Their Application as Molecular Biomarkers in Breast Cancer

Given their tumor-specific and stage-specific gene expression, long non-coding RNAs (lncRNAs) have demonstrated to be potential molecular biomarkers for diagnosis, prognosis, and treatment response. Particularly, the lncRNAs DSCAM-AS1 and GATA3-AS1 serve as examples of this because of their high subtype-specific expression profile in luminal B-like breast cancer. This makes them candidates to use as molecular biomarkers in clinical practice. However, lncRNA studies in breast cancer are limited in sample size and are restricted to the determination of their biological function, which represents an obstacle for its inclusion as molecular biomarkers of clinical utility. Nevertheless, due to their expression specificity among diseases, such as cancer, and their stability in body fluids, lncRNAs are promising molecular biomarkers that could improve the reliability, sensitivity, and specificity of molecular techniques used in clinical diagnosis. The development of lncRNA-based diagnostics and lncRNA-based therapeutics will be useful in routine medical practice to improve patient clinical management and quality of life.

Analysis of long noncoding RNAs expression profiles in the human cardiac fibroblasts with cardiac fibrosis

Cardiac fibrosis is a common pathological feature of cardiac remodelling process with disordered expression of multiple genes and eventually lead to heart failure. Emerging evidence suggests that long noncoding RNAs (lncRNAs) have emerged as critical regulators of various biological processes. However, the exact mechanisms of lncRNAs as mediators in cardiac fibrosis have not been fully elucidated. This study aimed to profile the lncRNA expression pattern in human cardiac fibroblasts (HCFs) with cardiac fibrosis. We treated HCFs with transforming growth factor-β (TGF-β) to induce their activation. Then, strand-specific RNA-seq was performed to profile and classify lncRNAs; and perform functional analysis in HCFs. We study the transformation of HCFs with molecular and cell biology methods. Among all identified lncRNA candidates, 176 and 526 lncRNAs were upregulated and downregulated respectively in TGF-β-stimulated HCFs compared with controls. Functional analyses revealed that the target genes of differentially expressed lncRNAs were mainly related to focal adhesion, metabolic pathways, Hippo signaling pathway, PI3K-Akt signaling pathway, regulation of actin cytoskeleton, and hypertrophic cardiomyopathy. As a representative, novel lncRNAs NONHSAG005537 and NONHSAG017620 inhibited the proliferation, migration, invasion, and transformation of HCFs induced by TGF-β. Collectively, our study established the expression signature of lncRNAs in cardiac fibrosis and demonstrated the cardioprotective role of NONHSAG005537 and NONHSAG017620 in cardiac fibrosis, providing a promising target for anti-fibrotic therapy.

Long Noncoding RNA PCGEM1 Facilitates Tumor Growth and Metastasis of Osteosarcoma by Sponging miR-433-3p and Targeting OMA1

OBJECTIVE

Osteosarcoma (OS) is regarded as one of the most common malignant bone tumors, mainly occurring in children and adolescents with high mortality. The dysregulation of lncRNAs is reported to regulate tumor development and be closely related to patient prognosis. Nevertheless, the role of long noncoding RNAs (lncRNAs) prostate-specific transcript 1 (PCGEM1) in OS remains uncharacterized. The current study aimed to explore the role of PCGEM1 in OS.

METHODS

Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to examine the expression of PCGEM1 in OS cell lines. CCK-8, colony formation, Transwell, and western blotting analyses were applied to measure OS cell viability, proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) after PCGEM1 downregulation. Nuclear-cytoplasmic fractionation, RNA pulldown, RNA immunoprecipitation (RIP), luciferase reporter assays were performed to verify the relationship among PCGEM1, miR-433-3p. and OMA1 in OS. The xenograft tumor models were established to evaluate the effect of PCGEM1 on tumor growth of OS.

RESULTS

In this study, we discovered that PCGEM1 knockdown inhibited cell proliferation, migration, invasion and EMT in OS (P < 0.05). Additionally, PCGEM1 directly bound to miR-433-3p (P < 0.01). OMA1 was confirmed to be a target gene of miR-433-3p (P < 0.05), positively regulated by PCGEM1 but negatively regulated by miR-433-3p. Rescue assays further verified that overexpression of OMA1 reversed the PCGEM1 knockdown-mediated inhibitory effect on the malignant phenotype in OS cells (P < 0.05). Moreover, knockdown of PCGEM1 inhibited tumor growth and metastasis in vivo (P < 0.05).

CONCLUSIONS

Overall, PCGEM1 mediated tumor growth and metastasis of OS by sponging miR-433-3p and regulating OMA1, which might provide an innovative strategy for OS diagnosis or treatment.

Distinct dosage compensations of ploidy-sensitive and -insensitive X chromosome genes during development and in diseases

The active X chromosome in mammals is upregulated to balance its dosage to autosomes during evolution. However, it is elusive why the known dosage compensation machinery showed uneven and small influence on X genes. Here, based on >20,000 transcriptomes, we identified two X gene groups (ploidy-sensitive [PSX] and ploidy-insensitive [PIX]), showing distinct but evolutionarily conserved dosage compensations (termed XAR). We demonstrated that XAR-PIX was downregulated whereas XAR-PSX upregulated at both RNA and protein levels across cancer types, in contrast with their trends during stem cell differentiation. XAR-PIX, but not XAR-PSX, was lower and correlated with autoantibodies and inflammation in patients of lupus, suggesting that insufficient dosage of PIX genes contribute to lupus pathogenesis. We further identified and experimentally validated two XAR regulators, TP53 and ATRX. Collectively, we provided insights into X dosage compensation in mammals and demonstrated different regulation of PSX and PIX and their pathophysiological roles in human diseases.

Systematic characterization of cancer transcriptome at transcript resolution

Transcribed RNAs undergo various regulation and modification to become functional transcripts. Notably, cancer transcriptome has not been fully characterized at transcript resolution. Herein, we carry out a reference-based transcript assembly across >1000 cancer cell lines. We identify 498,255 transcripts, approximately half of which are unannotated. Unannotated transcripts are closely associated with cancer-related hallmarks and show clinical significance. We build a high-confidence RNA binding protein (RBP)-transcript regulatory network, wherein most RBPs tend to regulate transcripts involved in cell proliferation. We identify numerous transcripts that are highly associated with anti-cancer drug sensitivity. Furthermore, we establish RBP-transcript-drug axes, wherein PTBP1 is experimentally validated to affect the sensitivity to decitabine by regulating KIAA1522-a6 transcript. Finally, we establish a user-friendly data portal to serve as a valuable resource for understanding cancer transcriptome diversity and its potential clinical utility at transcript level. Our study substantially extends cancer RNA repository and will facilitate anti-cancer drug discovery.

LncRNA HOXA11-AS promotes glioma malignant phenotypes and reduces its sensitivity to ROS via Tpl2-MEK1/2-ERK1/2 pathway

Our previous studies showed that dysregulation of the long noncoding RNA (lncRNA) HOXA11-AS plays an important role in the development of glioma. However, the molecular mechanism of HOXA11-AS in glioma remains largely unknown. In this study, we explore the molecular mechanisms underlying abnormal expression and biological function of HOXA11-AS for identifying novel therapeutic targets in glioma. The expression of HOXA11-AS, and the relationship between HOXA11-AS and the prognosis of glioma patients were analyzed using databases and glioma samples. Transcriptomics, proteomics, RIP, ChIRP, luciferase, and ChIP assays were used to explore its upstream and downstream targets in glioma. The role of HOXA11-AS in regulating the sensitivity of glioma cells to reactive oxygen species (ROS) was also investigated in vitro and in vivo. We found that HOXA11-AS was significantly upregulated in glioma, and was correlated with the poor prognosis of glioma patients. Ectopic expression of HOXA11-AS promoted the proliferation, migration, and invasion of glioma cells in vitro and in vivo. Mechanistically, HOXA11-AS acted as a molecular sponge for let-7b-5p in the cytoplasm, antagonizing its ability to repress the expression of CTHRC1, which activates the β-catenin/c-Myc pathway. In addition, c-Myc was involved in HOXA11-AS dysregulation via binding to its promoter region to form a self-activating loop. HOXA11-AS, functioned as a scaffold in the nucleus, also recruited transcription factor c-Jun to the Tpl2 promoter, which activates the Tpl2-MEK1/2-ERK1/2 pathway to promote ROS resistance in glioma. Importantly, HOXA11-AS knockdown could sensitize glioma cells to ROS. Above, oncogenic HOXA11-AS upregulates CTHRC1 expression as a ceRNA by adsorbing let-7b-5p, which activates c-Myc to regulate itself transcription. HOXA11-AS knockdown promotes ROS sensitivity in glioma cells by regulating the Tpl2-MEK1/2-ERK1/2 axis, demonstrating that HOXA11-AS may be translated to increase ROS sensitivity therapeutically.

LncBook 2.0: integrating human long non-coding RNAs with multi-omics annotations

LncBook, a comprehensive resource of human long non-coding RNAs (lncRNAs), has been used in a wide range of lncRNA studies across various biological contexts. Here, we present LncBook 2.0 (https://ngdc.cncb.ac.cn/lncbook), with significant updates and enhancements as follows: (i) incorporation of 119 722 new transcripts, 9632 new genes, and gene structure update of 21 305 lncRNAs; (ii) characterization of conservation features of human lncRNA genes across 40 vertebrates; (iii) integration of lncRNA-encoded small proteins; (iv) enrichment of expression and DNA methylation profiles with more biological contexts and (v) identification of lncRNA-protein interactions and improved prediction of lncRNA-miRNA interactions. Collectively, LncBook 2.0 accommodates a high-quality collection of 95 243 lncRNA genes and 323 950 transcripts and incorporates their abundant annotations at different omics levels, thereby enabling users to decipher functional significance of lncRNAs in different biological contexts.

RiceNCexp: a rice non-coding RNA co-expression atlas based on massive RNA-seq and small-RNA seq data

Non-coding RNAs (ncRNAs) play important roles in regulating expression of protein-coding genes. Although gene expression databases have emerged in a timely manner, a comprehensive expression database for ncRNAs is still lacking. Herein, we constructed a rice ncRNA co-expression atlas (RiceNCexp), based on 491 RNA-seq and 274 small RNA (sRNA)-seq datasets. RiceNCexp hosts four types of ncRNAs, namely lncRNAs, PHAS genes, miRNAs, and phasiRNAs. RiceNCexp provides comprehensive expression information for rice ncRNAs in 22 tissues/organs, an efficient tau-based mining tool for tissue-specific ncRNAs, and the robust co-expression analysis among ncRNAs or between ncRNAs and protein-coding genes, based on 116 pairs of RNA-seq and sRNA-seq libraries from the same experiments. In summary, RiceNCexp is a user-friendly and comprehensive rice ncRNA co-expression atlas and can be freely accessed at https://cbi.njau.edu.cn/RiceNCexp/.

Cell Taxonomy: a curated repository of cell types with multifaceted characterization

Single-cell studies have delineated cellular diversity and uncovered increasing numbers of previously uncharacterized cell types in complex tissues. Thus, synthesizing growing knowledge of cellular characteristics is critical for dissecting cellular heterogeneity, developmental processes and tumorigenesis at single-cell resolution. Here, we present Cell Taxonomy (https://ngdc.cncb.ac.cn/celltaxonomy), a comprehensive and curated repository of cell types and associated cell markers encompassing a wide range of species, tissues and conditions. Combined with literature curation and data integration, the current version of Cell Taxonomy establishes a well-structured taxonomy for 3,143 cell types and houses a comprehensive collection of 26,613 associated cell markers in 257 conditions and 387 tissues across 34 species. Based on 4,299 publications and single-cell transcriptomic profiles of ∼3.5 million cells, Cell Taxonomy features multifaceted characterization for cell types and cell markers, involving quality assessment of cell markers and cell clusters, cross-species comparison, cell composition of tissues and cellular similarity based on markers. Taken together, Cell Taxonomy represents a fundamentally useful reference to systematically and accurately characterize cell types and thus lays an important foundation for deeply understanding and exploring cellular biology in diverse species.

Transcriptome analysis identifies TODL as a novel lncRNA associated with proliferation, differentiation, and tumorigenesis in liposarcoma through FOXM1 Running Title: TODL lncRNA as a potential therapeutic target for liposarcoma

Liposarcoma, the most common soft tissue sarcoma, is a group of fat cell mesenchymal tumors with different histological subtypes. The dysregulation of long non-coding RNAs (lncRNAs) has been observed in human cancers including a few studies in sarcoma. However, the global transcriptome analysis and potential role of lncRNAs remain unexplored in liposarcoma. The present investigation uncovers the transcriptomic profile of liposarcoma by RNA sequencing to gain insight into the global transcriptional changes in liposarcoma. Our RNA sequencing analysis has identified that many oncogenic lncRNAs are differentially expressed in different subtypes of liposarcoma including MALAT1, PVT1, SNHG15, LINC00152, and MIR210HG. Importantly, we identified a highly overexpressed, unannotated, and novel lncRNA in dedifferentiated liposarcomas. We have named it TODL, transcript overexpressed in dedifferentiated liposarcoma. TODL lncRNA displayed significantly higher expression in dedifferentiated liposarcoma cell lines and patient samples. Interestingly, functional studies revealed that TODL lncRNA has an oncogenic function in liposarcoma cells by regulating proliferation, cell cycle, apoptosis, differentiation, and tumorigenesis in the murine model. Silencing of TODL lncRNA highlighted the enrichment of several key oncogenic signaling pathways including cell cycle, transcriptional misregulation, FOXM1 network, p53 signaling, PLK1 signaling, FoxO, and signaling Aurora signaling pathways. RNA pull-down assay revealed the binding of TODL lncRNA with FOXM1, an oncogenic transcription factor, and the key regulator of the cell cycle. Silencing of TODL lncRNA also induces adipogenesis in dedifferentiated liposarcomas. Altogether, our finding indicates that TODL could be utilized as a novel, specific diagnostic biomarker, and a pharmacological target for therapeutic development in controlling aggressive and metastatic dedifferentiated liposarcomas.

lncRNA DARS-AS1 Modulates TSPAN1-Mediated ITGA2 Hypomethylation by Interaction with miR-194-5p Thus Promoting Ovarian Cancer Progression

Objective

Ovarian cancer (OC) is usually called the "silent killer" due to its asymptomatic characteristics until advanced stages, thus being a significant threat to female health worldwide. In this work, we characterized an oncogenic DARS-AS1 role in OC.

Methods

The aggressiveness behaviors of the OC cell model were examined by CCK-8 assay, transwell invasion assay, flow cytometry, and immunoblotting analysis of apoptosis-related proteins. Interactions of miR-194-5p with lncRNA DARS-AS1 or TSPAN1 and of TSPAN1 with ITGA2 were validated by using a luciferase activity assay and chromatin immunoprecipitation (ChIP) assay.

Results

The OC cell model exhibited overexpressed lncRNA DARS-AS1 compared to normal cells. lncRNA DARS-AS1 knockdown led to reduced OC cell growth and metastasis while inducing the apoptosis in the OC cell model. lncRNA DARS-AS1 positively regulated TSPAN1 expression by binding with miR-194-5p and TSPAN1-mediated ITGA2 hypomethylation in OC cells. Further rescue function studies demonstrated that lncRNA DARS-AS1 affected OC cell viability, migration, invasion, and apoptosis ability by modulating miR-194-5p and TSPAN1 expressions.

Conclusion

Our work demonstrates that lncRNA DARS-AS1 promotes OC progression by modulating TSPAN1 and ITGA2 hypomethylation by binding with miR-194-5p.

Peroxidase is a novel potential marker in glioblastoma through bioinformatics method and experimental validation

Peroxidase (PXDN), a specific extracellular matrix (ECM)-associated protein, has been determined as a tumor indicator and therapeutic target in various tumors. However, the effects of PXDN in prognostic performance and clinical implications in glioblastoma multiforme (GBM) remains unknown. Here, we assessed PXDN expression pattern and its performance on prognosis among GBM cases from TCGA and CGGA databases. PXDN was up-regulated within GBM samples in comparison with normal control. High PXDN expression was a dismal prognostic indicator in GBM. Single cell RNA analysis was conducted to detect the cell localization of PXDN. We also set up a PPI network to explore the interacting protein associated with PXDN, including TSKU, COL4A1 and COL5A1. Consistently, functional enrichment analysis revealed that several cancer hallmarks were enriched in the GBM cases with high PXDN expression, such as epithelial-mesenchymal transition (EMT), fatty acid metabolism, glycolysis, hypoxia, inflammatory response, and Wnt/beta-catenin signaling pathway. Next, this study analyzed the association of PXDN expression and immunocyte infiltration. PXDN expression was in direct proportion to the infiltrating degrees of NK cells resting, T cells regulatory, M0 macrophage, monocytes and eosinophils. The roles of PXDN on immunity were further estimated by PXDN-associated immunomodulators. In addition, four prognosis-related lncRNAs co-expressed with PXDN were identified. Finally, we observed that PXDN depletion inhibits GBM cell proliferation and migration by in vitro experiments. Our data suggested that PXDN has the potential to be a powerful prognostic biomarker, which might offer a basis for developing therapeutic targets for GBM.

LINC-PINT suppresses cisplatin resistance in gastric cancer by inhibiting autophagy activation via epigenetic silencing of ATG5 by EZH2

Resistance to cisplatin (DDP) is a major obstacle in the clinical treatment of advanced gastric cancer (GC). Long noncoding RNA (lncRNA) play a significant regulatory role in the development and drug resistance of GC. In this study, we reported that the lncRNA LINC-PINT was downregulated in DDP-resistant GC cells. Functional studies showed that LINC-PINT inhibited proliferation and migration of DDP-resistant GC cells in vitro, and overexpression of LINC-PINT could enhance the sensitivity of DDP-resistant GC cells to DDP. Further investigation revealed that LINC-PINT recruited enhancer of zeste homolog 2 (EZH2) to the promotor of ATG5 to inhibit its transcription, leading to the suppression of autophagy and DDP resensitization. Collectively, our results revealed how the LINC-PINT/EZH2/ATG5 axis regulates autophagy and DDP resistance in GC. These data suggest that LINC-PINT may be a potential therapeutic target in GC.

Long Noncoding RNAs That Function in Nutrition: Lnc-ing Nutritional Cues to Metabolic Pathways

Long noncoding RNAs (lncRNAs) are sensitive to changing environments and play key roles in health and disease. Emerging evidence indicates that lncRNAs regulate gene expression to shape metabolic processes in response to changing nutritional cues. Here we review various lncRNAs sensitive to fasting, feeding, and high-fat diet in key metabolic tissues (liver, adipose, and muscle), highlighting regulatory mechanisms that trigger expression changes of lncRNAs themselves, and how these lncRNAs regulate gene expression of key metabolic genes in specific cell types or across tissues. Determining how lncRNAs respond to changes in nutrition is critical for our understanding of the complex downstream cascades following dietary changes and can shape how we treat metabolic disease. Furthermore, investigating sex biases that might influence lncRNA-regulated responses will likely reveal contributions toward the observed disparities between the sexes in metabolic diseases.

MOBT Alleviates Pulmonary Fibrosis through an lncITPF-hnRNP-l-Complex-Mediated Signaling Pathway

Pulmonary fibrosis is characterized by the destruction of alveolar architecture and the irreversible scarring of lung parenchyma, with few therapeutic options and effective therapeutic drugs. Here, we demonstrate the anti-pulmonary fibrosis of 3-(4-methoxyphenyl)-4-oxo-4H-1-benzopyran-7-yl(αS)-α,3,4-trihydroxybenzenepropanoate (MOBT) in mice and a cell model induced by bleomycin and transforming growth factor-β1. The anti-pulmonary fibrosis of MOBT was evaluated using a MicroCT imaging system for small animals, lung function analysis and H&E and Masson staining. The results of RNA fluorescence in situ hybridization, chromatin immunoprecipitation (ChIP)-PCR, RNA immunoprecipitation, ChIP-seq, RNA-seq, and half-life experiments demonstrated the anti-pulmonary fibrotic mechanism. Mechanistic dissection showed that MOBT inhibited lncITPF transcription by preventing p-Smad2/3 translocation from the cytoplasm to the nucleus, resulting in a reduction in the amount of the lncITPF–hnRNP L complex. The decreased lncITPF–hnRNP L complex reduced MEF2c expression by blocking its alternative splicing, which in turn inhibited the expression of MEF2c target genes, such as TAGLN2 and FMN1. Briefly, MOBT alleviated pulmonary fibrosis through the lncITPF–hnRNP-l-complex-targeted MEF2c signaling pathway. We hope that this study will provide not only a new drug candidate but also a novel therapeutic drug target, which will bring new treatment strategies for pulmonary fibrosis.

Identification and Validation of Immune-Related Long Non-Coding RNA Signature for Predicting Immunotherapeutic Response and Prognosis in NSCLC Patients Treated With Immunotherapy

Background

Numerous studies have reported that long non-coding RNAs (lncRNAs) play important roles in immune-related pathways in cancer. However, immune-related lncRNAs and their roles in predicting immunotherapeutic response and prognosis of non-small cell lung cancer (NSCLC) patients treated with immunotherapy remain largely unexplored.

Methods

Transcriptomic data from NSCLC patients were used to identify novel lncRNAs by a custom pipeline. ImmuCellAI was utilized to calculate the infiltration score of immune cells. The marker genes of immunotherapeutic response-related (ITR)-immune cells were used to identify immune-related (IR)-lncRNAs. A co-expression network was constructed to determine their functions. LASSO and multivariate Cox analyses were performed on the training set to construct an immunotherapeutic response and immune-related (ITIR)-lncRNA signature for predicting the immunotherapeutic response and prognosis of NSCLC. Four independent datasets involving NSCLC and melanoma patients were used to validate the ITIR-lncRNA signature.

Results

In total, 7,693 novel lncRNAs were identified for NSCLC. By comparing responders with non-responders, 154 ITR-lncRNAs were identified. Based on the correlation between the marker genes of ITR-immune cells and lncRNAs, 39 ITIR-lncRNAs were identified. A co-expression network was constructed and the potential functions of 38 ITIR-lncRNAs were annotated, most of which were related to immune/inflammatory-related pathways. Single-cell RNA-seq analysis was performed to confirm the functional prediction results of an ITIR-lncRNA, LINC01272. Four-ITIR-lncRNA signature was identified and verified for predicting the immunotherapeutic response and prognosis of NSCLC. Compared with non-responders, responders had a lower risk score in both NSCLC datasets (P<0.05). NSCLC patients in the high-risk group had significantly shorter PFS/OS time than those in the low-risk group in the training and testing sets (P<0.05). The AUC value was 1 of responsiveness in the training set. In melanoma validation datasets, patients in the high-risk group also had significantly shorter OS/PFS time than those in the low-risk group (P<0.05). The ITIR-lncRNA signature was an independent prognostic factor (P<0.001).

Conclusion

Thousands of novel lncRNAs in NSCLC were identified and characterized. In total, 39 ITIR-lncRNAs were identified, 38 of which were functionally annotated. Four ITIR-lncRNAs were identified as a novel ITIR-lncRNA signature for predicting the immunotherapeutic response and prognosis in NSCLC patients treated with immunotherapy.

Systematic Investigation of Immune-Related lncRNA Landscape Reveals a Potential Long Non-Coding RNA Signature for Predicting Prognosis in Renal Cell Carcinoma

Background: Renal cell carcinoma (RCC) is the predominant type of malignant tumor in kidney cancer. Finding effective biomarkers, particularly those based on the tumor immune microenvironments (TIME), is critical for the prognosis and diagnosis of RCC. Increasing evidence has revealed that long non-coding RNAs (lncRNAs) play a crucial role in cancer immunity. However, the comprehensive landscape of immune infiltration-associated lncRNAs and their potential roles in the prognosis and diagnosis of RCC remain largely unexplored.

Methods: Based on transcriptomic data of 261 RCC samples, novel lncRNAs were identified using a custom pipeline. RCC patients were classified into different immune groups using unsupervised clustering algorithms. Immune-related lncRNAs were obtained according to the immune status of RCC. Competing endogenous RNAs (ceRNA) regulation network was constructed to reveal their functions. Expression patterns and several tools such as miRanda, RNAhybrid, miRWalk were used to define lncRNAs-miRNAs-mRNAs interactions. Univariate Cox, LASSO, and multivariate Cox regression analyses were performed on the training set to construct a tumorigenesis-immune-infiltration-related (TIR)-lncRNA signature for predicting the prognosis of RCC. Independent datasets involving 531 RCC samples were used to validate the TIR-lncRNA signature.

Results: Tens of thousands of novel lncRNAs were identified in RCC samples. Comparing tumors with controls, 1,400 tumorigenesis-related (TR)-lncRNAs, 1269 TR-mRNAs, and 192 TR-miRNAs were obtained. Based on the infiltration of immune cells, RCC patients were classified into three immune clusters. By comparing immune-high with immune-low groups, 241 TIR-lncRNAs were identified, many of which were detected in urinary samples. Based on lncRNA-miRNA-mRNA interactions, we constructed a ceRNA network, which included 25 TR-miRNAs, 28 TIR-lncRNAs, and 66 TIR-mRNAs. Three TIR lncRNAs were identified as a prognostic signature for RCC. RCC patients in the high-risk group exhibited worse OS than those in the low-risk group in the training and testing sets (p &lt; 0.01). The AUC was 0.9 in the training set. Univariate and multivariate Cox analyses confirmed that the TIR-lncRNA signature was an independent prognostic factor in the training and testing sets.

Conclusion: Based on the constructed immune-related lncRNA landscape, 241 TIR-lncRNAs were functionally characterized, three of which were identified as a novel TIR-lncRNA signature for predicting the prognosis of RCC.

PINTology: A short history of the lncRNA LINC-PINT in different diseases

LINC-PINT is a p53-induced long intergenic noncoding transcript that plays a crucial role in many diseases, especially cancer. This long noncoding RNA (lncRNA) gene produces in total 102 (LNCipedia) alternatively spliced variants (LINC-PINT:1 to LINC-PINT:102). The functions of known variants include RNA transcripts, host transcripts for circular RNA (circRNA) generation and as sources for the translation of short peptides. In most human tumors, LINC-PINT is down-regulated where it serves as a tumor suppressor. However, the diversity of its functions in other maladies signifies its general clinical importance. Current LINC-PINT molecular functions include RNA-protein interactions, miRNA sponging and epigenetic modulation with these mechanisms operating in different cellular contexts to exert effects on biological processes ranging from DNA damage responses, cell cycle and growth arrest, senescence, cell migration and invasion, and apoptosis. Genetic polymorphisms in LINC-PINT have also been functionally associated with cancer and other pathologies including the autoimmune diseases pemphigus foliaceus and arthritis. Hence, LINC-PINT shows great potential as a clinical biomarker, especially for the diagnosis and prognosis of cancer. In this review, we explore the current knowledge highlighting the distinctive molecular functions of LINC-PINT in specific cancers and other disease states. This article is categorized under: RNA in Disease and Development > RNA in Disease.

Long Noncoding RNA HCP5 Contributes to Nasopharyngeal Carcinoma Progression by Targeting MicroRNA-128-3p

Aim

To determine the role and underlying mechanism of lncRNA HCP5 in nasopharyngeal carcinoma (NPC).

Method

The expression of HCP5 and miR-128-3p was assessed by qRT-PCR. CCK-8, EdU staining, and transwell were performed to determine cell progression. A nude mouse xenograft tumor model was carried out to detect the role of HCP5 in vivo. The luciferase assay was performed to confirm the function between lncRNA HCP5 and miR-128-3p.

Results

The increased level of HCP5 was observed in NPC tissues. Silencing of HCP5 prevented tumor progression in vitro and in vivo. The luciferase assay verified that HCP5 could bind with miR-128-3p. Furthermore, forced expression of miR-128-3p could prevent the function of HCP5 on NPC cells.

Conclusion

lncRNA HCP5 could regulate NPC cell progression via sponging miR-128-3p, which might serve as a potential therapy target of NPC.

Circulating lnc-LOC as a novel noninvasive biomarker in the treatment surveillance of acute promyelocytic leukaemia

BACKGROUND

Acute promyelocytic leukaemia (APL) is a unique subtype of acute myeloid leukaemia (AML) characterized by haematopoietic failure caused by the accumulation of abnormal promyelocytic cells in bone marrow (BM). However, indispensable BM biopsy frequently afflicts patients in leukaemia surveillance, which increases the burden on patients and reduces compliance. This study aimed to explore whether the novel circulating long noncoding RNA LOC100506453 (lnc-LOC) could be a target in diagnosis, assess the treatment response and supervise the minimal residual disease (MRD) of APL, thereby blazing a trail in noninvasive lncRNA biomarkers of APL.

METHODS

Our study comprised 100 patients (40 with APL and 60 with non-APL AML) and 60 healthy donors. BM and peripheral blood (PB) sample collection was accomplished from APL patients at diagnosis and postinduction. Quantitative real-time PCR (qRT-PCR) was conducted to evaluate lnc-LOC expression. A receiver operating characteristic (ROC) analysis was implemented to analyse the value of lnc-LOC in the diagnosis of APL and treatment monitoring. For statistical analysis, the Mann-Whitney U test, a t test, and Spearman's rank correlation test were utilized.

RESULTS

Our results showed that BM lnc-LOC expression was significantly different between APL and healthy donors and non-APL AML. lnc-LOC was drastically downregulated in APL patients' BM after undergoing induction therapy. Lnc-LOC was upregulated in APL cell lines and downregulated after all-trans retinoic acid (ATRA)-induced myeloid differentiation, preliminarily verifying that lnc-LOC has the potential to be considered a treatment monitoring biomarker. PB lnc-LOC was positively correlated with BM lnc-LOC in APL patients, non-APL AML patients and healthy donors and decreased sharply after complete remission (CR). However, upregulated lnc-LOC was manifested in relapsed-refractory patients. A positive correlation was revealed between PB lnc-LOC and PML-RARα transcript levels in BM samples. Furthermore, we observed a positive correlation between PB lnc-LOC and BM lnc-LOC expression in APL patients, suggesting that lnc-LOC can be utilized as a noninvasive biomarker for MRD surveillance.

CONCLUSIONS

Our study demonstrated that PB lnc-LOC might serve as a novel noninvasive biomarker in the treatment surveillance of APL, and it innovated the investigation and application of newly found lncRNAs in APL noninvasive biomarkers used in diagnosis and detection.

LncRNA SND1-IT1 facilitates TGF-β1-induced epithelial-to-mesenchymal transition via miR-124/COL4A1 axis in gastric cancer

The transformation of tumor cells from an epithelial to a mesenchymal-like phenotype, designated as epithelial-to-mesenchymal transition (EMT), represents a key hallmark of human cancer metastasis, including gastric cancer (GC). However, a large set of non-coding RNAs have been studied for their functions that initiate or inhibit this phenotypic switch in GC cells by regulating oncogenes or tumor suppressors. In this paper, we aimed to identify lncRNA SND1-IT1, miR-124, and COL4A1 gene in the context of GC with a specific focus on their effects on transforming growth factor β1 (TGF-β1)-induced EMT. The study included 52 paired samples of lesion tissues and adjacent lesion-free tissues surgically resected from patients diagnosed with GC. HGC-27 cells were stimulated with exogenous TGF-β1 (2 ng/mL). Expression of lncRNA SND1-IT1, miR-124, and COL4A1 was determined by RT-qPCR. CCK-8 assays, Transwell assays, immunoblotting analysis of EMT-specific markers, and tumor invasion markers were performed to evaluate cell viability, migration, and invasion of cultured HGC-27 cells. Luciferase activity assay was employed to examine miR-124 binding with lncRNA SND1-IT1 and COL4A1, respectively. LncRNA SND1-IT1 was upregulated in GC tissues and cells. TGF-β1-stimulated EMT and regulated lncRNA SND1-IT1, miR-124, and COL4A1 expressions in HGC-27 cells. LncRNA SND1-IT1 knockdown tempered HGC-27 cell viability, migration and invasion. LncRNA SND1-IT1 participated in TGF-β1-stimulated EMT in GC by sponging miR-124. MiR-124 attenuated TGF-β1-stimulated EMT in GC by targeting COL4A1. These results primarily demonstrated TGF-β1 can regulate cancer cell migration, invasion and stimulate EMT through the SND1-IT1/miR-124/COL4A1 axis in GC.

Prediction of New Risk Genes and Potential Drugs for Rheumatoid Arthritis from Multiomics Data

Rheumatoid arthritis (RA) is an autoimmune and inflammatory disease for which there is a lack of therapeutic options. Genome-wide association studies (GWASs) have identified over 100 genetic loci associated with RA susceptibility; however, the most causal risk genes (RGs) associated with, and molecular mechanism underlying, RA remain unknown. In this study, we collected 95 RA-associated loci from multiple GWASs and detected 87 candidate high-confidence risk genes (HRGs) from these loci via integrated multiomics data (the genome-scale chromosome conformation capture data, enhancer-promoter linkage data, and gene expression data) using the Bayesian integrative risk gene selector (iRIGS). Analysis of these HRGs indicates that these genes were indeed, markedly associated with different aspects of RA. Among these, 36 and 46 HRGs have been reported to be related to RA and autoimmunity, respectively. Meanwhile, most novel HRGs were also involved in the significantly enriched RA-related biological functions and pathways. Furthermore, drug repositioning prediction of the HRGs revealed three potential targets (ERBB2, IL6ST, and MAPK1) and nine possible drugs for RA treatment, of which two IL-6 receptor antagonists (tocilizumab and sarilumab) have been approved for RA treatment and four drugs (trastuzumab, lapatinib, masoprocol, and arsenic trioxide) have been reported to have a high potential to ameliorate RA. In summary, we believe that this study provides new clues for understanding the pathogenesis of RA and is important for research regarding the mechanisms underlying RA and the development of therapeutics for this condition.

FibroDB: Expression Analysis of Protein-Coding and Long Non-Coding RNA Genes in Fibrosis

Most long non-coding RNAs (lncRNAs) are expressed at lower levels than protein-coding genes and their expression is often restricted to specific cell types, certain time points during development, and various stress and disease conditions, respectively. To revisit this long-held concept, we focused on fibroblasts, a common cell type in various organs and tissues. Using fibroblasts and changes in their expression profiles during fibrosis as a model system, we show that the overall expression level of lncRNA genes is significantly lower than that of protein-coding genes. Furthermore, we identified lncRNA genes whose expression is upregulated during fibrosis. Using dermal fibroblasts as a model, we performed loss-of-function experiments and show that the knockdown of the lncRNAs LINC00622 and LINC01711 result in gene expression changes associated with cellular and inflammatory responses, respectively. Since there are no lncRNA databases focused on fibroblasts and fibrosis, we built a web application, FibroDB, to further promote functional and mechanistic studies of fibrotic lncRNAs.

Long RNA-Mediated Chromatin Regulation in Fission Yeast and Mammals

As part of a complex network of genome control, long regulatory RNAs exert significant influences on chromatin dynamics. Understanding how this occurs could illuminate new avenues for disease treatment and lead to new hypotheses that would advance gene regulatory research. Recent studies using the model fission yeast Schizosaccharomyces pombe (S. pombe) and powerful parallel sequencing technologies have provided many insights in this area. This review will give an overview of key findings in S. pombe that relate long RNAs to multiple levels of chromatin regulation: histone modifications, gene neighborhood regulation in cis and higher-order chromosomal ordering. Moreover, we discuss parallels recently found in mammals to help bridge the knowledge gap between the study systems.

Illuminating lncRNA Function Through Target Prediction

Most of the transcribed human genome codes for noncoding RNAs (ncRNAs), and long noncoding RNAs (lncRNAs) make for the lion's share of the human ncRNA space. Despite growing interest in lncRNAs, because there are so many of them, and because of their tissue specialization and, often, lower abundance, their catalog remains incomplete and there are multiple ongoing efforts to improve it. Consequently, the number of human lncRNA genes may be lower than 10,000 or higher than 200,000. A key open challenge for lncRNA research, now that so many lncRNA species have been identified, is the characterization of lncRNA function and the interpretation of the roles of genetic and epigenetic alterations at their loci. After all, the most important human genes to catalog and study are those that contribute to important cellular functions-that affect development or cell differentiation and whose dysregulation may play a role in the genesis and progression of human diseases. Multiple efforts have used screens based on RNA-mediated interference (RNAi), antisense oligonucleotide (ASO), and CRISPR screens to identify the consequences of lncRNA dysregulation and predict lncRNA function in select contexts, but these approaches have unresolved scalability and accuracy challenges. Instead-as was the case for better-studied ncRNAs in the past-researchers often focus on characterizing lncRNA interactions and investigating their effects on genes and pathways with known functions. Here, we focus most of our review on computational methods to identify lncRNA interactions and to predict the effects of their alterations and dysregulation on human disease pathways.

Long Noncoding RNA ENSG00000254693 Promotes Diabetic Kidney Disease via Interacting with HuR

Diabetic kidney disease (DKD) is one of the most common complications of diabetes mellitus (DM), without suitable therapies, causing end-stage renal diseases (ESRDs) ultimately. Moreover, there is increasing evidence demonstrating that long noncoding RNAs (lncRNAs) play crucial roles in the development of DKD. Our RNA sequencing data revealed a large group of differentially expressed lncRNAs in renal tissues of DKD, of which lncRNA ENSG00000254693 (lncRNA 254693 for short) changed drastically. In this study, we found that the expression of lncRNA 254693 was increased in both DKD patients and high-glucose-induced human podocytes. 5'/3'RACE and Northern blot assays were used to find the full length of lncRNA ENSG00000254693 which is 558 nucleotides and nonisoform that existed in human podocyte. Downregulation of lncRNA 254693 remarkably reversed the elevation of inflammation, apoptosis, and podocyte injury caused by high glucose. Then, we did bioinformatics analysis via RBPDB and found that lncRNA 254693 can combine with HuR, a RNA binding protein. Meanwhile, immunofluorescence and in situ hybridization double staining was used to prove the existence of colocalization between them. Intriguingly, lncRNA 254693 knockdown decreased HuR levels, while HuR knockdown also decreased the level of lncRNA 254693 and its stability. After this, RNA immunoprecipitation assay results confirmed the binding association between them again. In addition, we found that HuR was increased in high glucose-induced podocytes, and the silence of HuR could alleviate podocyte injury, inflammation, and apoptosis. These results together suggested a novel feedback regulation between lncRNA 254693 and HuR which could involve in podocyte injury and may serve as a predicted target for DKD therapies.

H19: A vital long noncoding RNA in the treatment of diabetes and diabetic complications

BACKGROUND

Increasing academic efforts have been made to explore the correlation of long noncoding RNAs (lncRNAs) with human diseases, particularly metabolic diseases like diabetes mellitus. Taking lncRNA H19 as an example, this review intends to reveal the functions and mechanism of lncRNA H19 in diabetes mellitus and diabetic complications.

METHODS

The research results associated with lncRNA H19 and diabetes mellitus are collected and summarized on PubMed.

CONCLUSION

LncRNA H19 is a potential instructive marker for the treatment of diabetes mellitus and diabetic complications.

Targeting Epigenetic Mechanisms to Treat Alcohol Use Disorders (AUD)

BACKGROUND

The impact of abusive alcohol consumption on human health is remarkable. According to the World Health Organization (WHO), approximately 3.3 million people die annually because of harmful alcohol consumption (the figure represents around 5.9% of global deaths). Alcohol Use Disorder (AUD) is a chronic disease where individuals exhibit compulsive alcohol drinking and present negative emotional states when they do not drink. In the most severe manifestations of AUD, the individuals lose control over intake despite a decided will to stop drinking. Given the multiple faces and the specific forms of this disease, the term AUD often appears in the plural (AUDs). Since only a few approved pharmacological treatments are available to treat AUD and they do not apply to all individuals or AUD forms, the search for compounds that may help to eliminate the burden of the disease and complement other therapeutical approaches is necessary.

METHODS

This work reviews recent research focused on the involvement of epigenetic mechanisms in the pathophysiology of AUD. Excessive drinking leads to chronic and compulsive consumption that eventually damages the organism. The central nervous system is a key target and is the focus of this study. The search for the genetic and epigenetic mechanisms behind the intricated dysregulation induced by ethanol will aid researchers in establishing new therapy approaches.

CONCLUSION

Recent findings in the field of epigenetics are essential and offer new windows for observation and research. The study of small molecules that inhibit key epienzymes involved in nucleosome architecture dynamics is necessary in order to prove their action and specificity in the laboratory and to test their effectivity and safety in clinical trials with selected patients bearing defined alterations caused by ethanol.

Non-coding Natural Antisense Transcripts: Analysis and Application

Non-coding natural antisense transcripts (ncNATs) are regulatory RNA sequences that are transcribed in the opposite direction to protein-coding or non-coding transcripts. These transcripts are implicated in a broad variety of biological and pathological processes, including tumorigenesis and oncogenic progression. With this complex field still in its infancy, annotations, expression profiling and functional characterisations of ncNATs are far less comprehensive than those for protein-coding genes, pointing out substantial gaps in the analysis and characterisation of these regulatory transcripts. In this review, we discuss ncNATs from an analysis perspective, in particular regarding the use of high-throughput sequencing strategies, such as RNA-sequencing, and summarize the unique challenges of investigating the antisense transcriptome. Finally, we elaborate on their potential as biomarkers and future targets for treatment, focusing on cancer.

LncGSEA: a versatile tool to infer lncRNA associated pathways from large-scale cancer transcriptome sequencing data

Background

Long non-coding RNAs (lncRNAs) are a growing focus in cancer research. Deciphering pathways influenced by lncRNAs is important to understand their role in cancer. Although knock-down or overexpression of lncRNAs followed by gene expression profiling in cancer cell lines are established approaches to address this problem, these experimental data are not available for a majority of the annotated lncRNAs.

Results

As a surrogate, we present lncGSEA, a convenient tool to predict the lncRNA associated pathways through Gene Set Enrichment Analysis of gene expression profiles from large-scale cancer patient samples. We demonstrate that lncGSEA is able to recapitulate lncRNA associated pathways supported by literature and experimental validations in multiple cancer types.

Conclusions

LncGSEA allows researchers to infer lncRNA regulatory pathways directly from clinical samples in oncology. LncGSEA is written in R, and is freely accessible at https://github.com/ylab-hi/lncGSEA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-021-07900-y.

The role of long noncoding RNA THAP9-AS1 in the osteogenic differentiation of dental pulp stem cells via the miR-652-3p/VEGFA axis

Dental pulp stem cells (DPSCs) are multipotent and may play crucial roles in dentin-pulp regeneration. Recent studies have revealed that long noncoding RNAs (lncRNAs) are implicated in the osteogenic differentiation of DPSCs. However, the specific role and potential mechanisms of the lncRNA trihydroxyacetophenone domain containing nine antisense RNA 1 (THAP9-AS1) during osteogenic differentiation of DPSCs remain unknown. In the present study, we determined that THAP9-AS1 expression was upregulated during osteogenic differentiation of DPSCs. Moreover, we investigated the biological functions of THAP9-AS1 during osteogenic differentiation of DPSCs by loss-of-function assays. THAP9-AS1 knockdown inhibited osteogenic differentiation of DPSCs by decreasing alkaline phosphatase activity, alkaline phosphatase-positive cell ratio, mineralizing matrix and mRNA, and protein levels of early osteogenic-markers. We also found that THAP9-AS1 interacted with miR-652-3p, whose downstream gene target is vascular endothelial growth factor A (VEGFA). In addition, rescue assays indicated that VEGFA rescued the effects of THAP9-AS1 knockdown during osteogenic differentiation of DPSCs. In summary, we verified that knockdown of THAP9-AS1 inhibits osteogenic differentiation of DPSCs via the miR-652-3p/VEGFA axis. Our findings may be helpful to extend research on the mechanisms underlying osteogenic differentiation of DPSCs.

Single-cell Long Non-coding RNA Landscape of T Cells in Human Cancer Immunity

The development of new biomarkers or therapeutic targets for cancer immunotherapies requires deep understanding of T cells. To date, the complete landscape and systematic characterization of long noncoding RNAs (lncRNAs) in T cells in cancer immunity are lacking. Here, by systematically analyzing full-length single-cell RNA sequencing (scRNA-seq) data of more than 20,000 libraries of T cells across three cancer types, we provided the first comprehensive catalog and the functional repertoires of lncRNAs in human T cells. Specifically, we developed a custom pipeline for de novotranscriptome assembly and obtained a novel lncRNA catalog containing 9433 genes. This increased the number of current human lncRNA catalog by 16% and nearly doubled the number of lncRNAs expressed in T cells. We found that a portion of expressed genes in single T cells were lncRNAs which had been overlooked by the majority of previous studies. Based on metacell maps constructed by the MetaCell algorithm that partitions scRNA-seq datasets into disjointed and homogenous groups of cells (metacells), 154 signature lncRNA genes were identified. They were associated with effector, exhausted, and regulatory T cell states. Moreover, 84 of them were functionally annotated based on the co-expression networks, indicating that lncRNAs might broadly participate in the regulation of T cell functions. Our findings provide a new point of view and resource for investigating the mechanisms of T cell regulation in cancer immunity as well as for novel cancer-immune biomarker development and cancer immunotherapies