An expanded landscape of human long noncoding RNA

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

Long non-coding RNA exploration for mesenchymal stem cell characterisation

BACKGROUND

The development of RNA sequencing (RNAseq) and the corresponding emergence of public datasets have created new avenues of transcriptional marker search. The long non-coding RNAs (lncRNAs) constitute an emerging class of transcripts with a potential for high tissue specificity and function. Therefore, we tested the biomarker potential of lncRNAs on Mesenchymal Stem Cells (MSCs), a complex type of adult multipotent stem cells of diverse tissue origins, that is frequently used in clinics but which is lacking extensive characterization.

RESULTS

We developed a dedicated bioinformatics pipeline for the purpose of building a cell-specific catalogue of unannotated lncRNAs. The pipeline performs ab initio transcript identification, pseudoalignment and uses new methodologies such as a specific k-mer approach for naive quantification of expression in numerous RNAseq data. We next applied it on MSCs, and our pipeline was able to highlight novel lncRNAs with high cell specificity. Furthermore, with original and efficient approaches for functional prediction, we demonstrated that each candidate represents one specific state of MSCs biology.

CONCLUSIONS

We showed that our approach can be employed to harness lncRNAs as cell markers. More specifically, our results suggest different candidates as potential actors in MSCs biology and propose promising directions for future experimental investigations.

Multi-omics annotation of human long non-coding RNAs

LncRNAs (long non-coding RNAs) are pervasively transcribed in the human genome and also extensively involved in a variety of essential biological processes and human diseases. The comprehensive annotation of human lncRNAs is of great significance in navigating the functional landscape of the human genome and deepening the understanding of the multi-featured RNA world. However, the unique characteristics of lncRNAs as well as their enormous quantity have complicated and challenged the annotation of lncRNAs. Advances in high-throughput sequencing technologies give rise to a large volume of omics data that are generated at an unprecedented rate and scale, providing possibilities in the identification, characterization and functional annotation of lncRNAs. Here, we review the recent important discoveries of human lncRNAs through analysis of various omics data and summarize specialized lncRNA database resources. Moreover, we highlight the multi-omics integrative analysis as a powerful strategy to efficiently discover and characterize the functional lncRNAs and elucidate their potential molecular mechanisms.

Integrated Analysis of Long Noncoding RNA Expression Profiles in Acute-on-Chronic Liver Failure

People infected with chronic hepatitis B virus (HBV) might progress to acute-on-chronic liver failure (ACLF) with a high fatality rate. Long noncoding RNAs (lncRNAs) are involved in human diseases, but it is unknown whether lncRNAs are involved in the progression of chronic HBV infection to ACLF. Hence, this study is aimed at systemically identifying and characterizing the landscape and the molecular mechanism of lncRNAs in the pathogenesis of chronic HBV infection progress to ACLF. RNA sequencing (RNA-Seq) of peripheral blood samples from 5 ACLF and 5 HBV infection patients was performed. We detected 9733 lncRNAs, including 406 annotated lncRNAs and 9327 novel lncRNAs. A total of 407 lncRNAs were found to be significantly dysregulated in the patients with ACLF as compared with those in the chronic HBV infection patients. The flanking protein-coding genes of differentially expressed lncRNAs were enriched with pathways that might contribute to the pathogenesis of ACLF, such as the WNT signaling pathway. Furthermore, 9 selected differentially expressed lncRNAs validated by the qRT-PCR, showing that the expression patterns of these 9 lncRNAs were consistent with the RNA-Seq data. Four selected differentially expressed lncRNAs were also validated in another patient cohort comprising 80 patients with ACLF and 65 patients with chronic HBV infection. Aberrant lncRNAs might be used to develop novel diagnostic biomarkers or drug targets for ACLF.

Global miRNA dosage control of embryonic germ layer specification

MicroRNAs (miRNAs) have essential functions during embryonic development, and their dysregulation causes cancer^1,2. Altered global miRNA abundance is found in different tissues and tumours, which implies that precise control of miRNA dosage is important^1,3,4, but the underlying mechanism(s) of this control remain unknown. The protein complex Microprocessor, which comprises one DROSHA and two DGCR8 proteins, is essential for miRNA biogenesis^5-7. Here we identify a developmentally regulated miRNA dosage control mechanism that involves alternative transcription initiation (ATI) of DGCR8. ATI occurs downstream of a stem-loop in DGCR8 mRNA to bypass an autoregulatory feedback loop during mouse embryonic stem (mES) cell differentiation. Deletion of the stem-loop causes imbalanced DGCR8:DROSHA protein stoichiometry that drives irreversible Microprocessor aggregation, reduced primary miRNA processing, decreased mature miRNA abundance, and widespread de-repression of lipid metabolic mRNA targets. Although global miRNA dosage control is not essential for mES cells to exit from pluripotency, its dysregulation alters lipid metabolic pathways and interferes with embryonic development by disrupting germ layer specification in vitro and in vivo. This miRNA dosage control mechanism is conserved in humans. Our results identify a promoter switch that balances Microprocessor autoregulation and aggregation to precisely control global miRNA dosage and govern stem cell fate decisions during early embryonic development.

Population-scale tissue transcriptomics maps long non-coding RNAs to complex disease

Long non-coding RNA (lncRNA) genes have well-established and important impacts on molecular and cellular functions. However, among the thousands of lncRNA genes, it is still a major challenge to identify the subset with disease or trait relevance. To systematically characterize these lncRNA genes, we used Genotype Tissue Expression (GTEx) project v8 genetic and multi-tissue transcriptomic data to profile the expression, genetic regulation, cellular contexts, and trait associations of 14,100 lncRNA genes across 49 tissues for 101 distinct complex genetic traits. Using these approaches, we identified 1,432 lncRNA gene-trait associations, 800 of which were not explained by stronger effects of neighboring protein-coding genes. This included associations between lncRNA quantitative trait loci and inflammatory bowel disease, type 1 and type 2 diabetes, and coronary artery disease, as well as rare variant associations to body mass index.

Clinical value of lncRNA CCAT1 in serum extracellular vesicles as a potential biomarker for gastric cancer

Long non-coding RNAs (lncRNAs) in extracellular vesicles (EVs) are considered to be novel non-invasive biomarkers for gastric cancer (GC). lncRNA colon cancer-associated transcript 1 (CCAT1) is aberrantly expressed in certain types of cancer. However, the role of EV lncRNA CCAT1 in patients with GC remains unclear. The current study aimed to assess the expression levels of lncRNA CCAT1 in the serum EVs of patients with GC and evaluate its potential clinical value. EVs were isolated from serum using a commercial kit and ultracentrifugation, and were identified by transmission electron microscopy, nanoparticle tracking analysis and western blotting. Serum EV lncRNA CCAT1 levels in patients with GC, chronic gastritis or atypical hyperplasia and healthy control subjects were detected by reverse transcription-quantitative PCR. Additionally, lncRNA CCAT1 was detected in GC and adjacent non-cancerous tissue samples. Serum EVs were successfully isolated and identified in all patients. The results revealed that serum EV lncRNA CCAT1 levels in patients with GC were significantly higher compared with those in healthy controls, patients with chronic gastritis or atypical hyperplasia (all P<0.05). Additionally, EV lncRNA CCAT1 expression levels were significantly different among various groups based on the depth of invasion, distant metastasis and the Tumor-Node-Metastasis stage. The area under the curve (AUC) value of EV lncRNA CCAT1 was 0.890 [95% confidence interval (CI), 0.826–0.937] with 79.6% sensitivity and 92.6% specificity. The combination of EV lncRNA CCAT1 and carcinoembryonic antibody produced an AUC value of 0.910 (95% CI, 0.849–0.951) with the sensitivity and specificity of 80.5 and 92.6%, respectively. In addition, lncRNA CCAT1 was determined to be stable in serum EVs. The expression levels of lncRNA CCAT1 in GC tissue were positively correlated with those in serum EVs, and high levels of lncRNA CCAT1 were associated with a low disease-free survival rate in patients with GC. The results of the present study demonstrated that serum EV lncRNA CCAT1 levels were upregulated in patients with GC compared with those healthy subjects and patients with other illnesses, and may therefore be used as a novel biomarker for this type of cancer.

Long noncoding RNA (lncRNA) EIF3J-DT induces chemoresistance of gastric cancer via autophagy activation

Chemotherapy is currently the main treatment for unresectable or advanced postoperative gastric cancers. However, its efficacy is negatively affected by the occurrence of chemoresistance, which severely affects patient prognosis. Recently, dysregulation in autophagy has been suggested as a potential mechanism for chemoresistence, and long noncoding RNA (lncRNA) also shows its regulatory role in cancer drug resistance. Using RNA sequencing, we found that lncRNA EIF3J-DT was highly expressed in drug-resistant gastric cancer cells. In-vitro and in-vivo experiments showed that EIF3J-DT activated autophagy and induced drug resistance in gastric cancer cells by targeting ATG14. Bioinformatics and experimental results showed that EIF3J-DT regulated the expression of ATG14 through direct binding to enhance stabilization of ATG14 mRNA and via blocking the degradation of ATG14 mRNA through competitively binding with microRNA (miRNA) MIR188-3p. Therefore, EIF3J-DT increased the expression of ATG14, contributing to activation of autophagy and chemoresistance. Furthermore, it was confirmed that EIF3J-DT and ATG14 were highly expressed in gastric cancer patients resistant to chemotherapy, and this was closely associated with patient prognosis. In conclusion, EIF3J-DT is involved in the regulation of autophagy and chemoresistance in gastric cancer cells by targeting ATG14. It may be a suitable new target for enhancing chemosensitivity and improving prognosis.Abbreviations: 3-MA: 3-methyladenine; 5-Fu: 5-fluorouracil; ATG: autophagy related; C-CASP3: cleaved caspase 3; C-CASP7: cleaved caspase 7; C-PARP: cleaved PARP; CQ: chloroquine; CR: complete response; DIG: digoxigenin; ESR1: estrogen receptor 1; FBS: fetal bovine serum; FISH: fluorescence in situ hybridization; IHC: immunohistochemistry; ISH: in situ hybridization; lncRNA: long noncoding RNA; miRNA: microRNA; MUT: mutant; NC: negative control; OXA: oxaliplatin; PBS: phosphate-buffered saline; PD: progressive disease; PFA: paraformaldehyde; PR: partial response; qPCR: quantitative polymerase chain reaction; RAPA: rapamycin; SD: stable disease; TEM: transmission electron microscopy; WT: wild type.

Non-Coding RNAs in Cancer Diagnosis and Therapy: Focus on Lung Cancer

Over the last several decades, clinical evaluation and treatment of lung cancers have largely improved with the classification of genetic drivers of the disease, such as EGFR, ALK, and ROS1. There are numerous regulatory factors that exert cellular control over key oncogenic pathways involved in lung cancers. In particular, non-coding RNAs (ncRNAs) have a diversity of regulatory roles in lung cancers such that they have been shown to be involved in inducing proliferation, suppressing apoptotic pathways, increasing metastatic potential of cancer cells, and acquiring drug resistance. The dysregulation of various ncRNAs in human cancers has prompted preclinical studies examining the therapeutic potential of restoring and/or inhibiting these ncRNAs. Furthermore, ncRNAs demonstrate tissue-specific expression in addition to high stability within biological fluids. This makes them excellent candidates as cancer biomarkers. This review aims to discuss the relevance of ncRNAs in cancer pathology, diagnosis, and therapy, with a focus on lung cancer.

A Five Immune-Related lncRNA Signature as a Prognostic Target for Glioblastoma

Background: A variety of regulatory approaches including immune modulation have been explored as approaches to either eradicate antitumor response or induce suppressive mechanism in the glioblastoma microenvironment. Thus, the study of immune-related long noncoding RNA (lncRNA) signature is of great value in the diagnosis, treatment, and prognosis of glioblastoma.

Methods: Glioblastoma samples with lncRNA sequencing and corresponding clinical data were acquired from the Cancer Genome Atlas (TCGA) database. Immune-lncRNAs co-expression networks were built to identify immune-related lncRNAs via Pearson correlation. Based on the median risk score acquired in the training set, we divided the samples into high- and low-risk groups and demonstrate the survival prediction ability of the immune-related lncRNA signature. Both principal component analysis (PCA) and gene set enrichment analysis (GSEA) were used for immune state analysis.

Results: A cohort of 151 glioblastoma samples and 730 immune-related genes were acquired in this study. A five immune-related lncRNA signature (AC046143.1, AC021054.1, AC080112.1, MIR222HG, and PRKCQ-AS1) was identified. Compared with patients in the high-risk group, patients in the low-risk group showed a longer overall survival (OS) in the training, validation, and entire TCGA set (p = 1.931e-05, p = 1.706e-02, and p = 3.397e-06, respectively). Additionally, the survival prediction ability of this lncRNA signature was independent of known clinical factors and molecular features. The area under the ROC curve (AUC) and stratified analyses were further performed to verify its optimal survival predictive potency. Of note, the high-and low-risk groups exhibited significantly distinct immune state according to the PCA and GSEA analyses.

Conclusions: Our study proposes that a five immune-related lncRNA signature can be utilized as a latent indicator of prognosis and potential therapeutic approach for glioblastoma.

LncExpDB: an expression database of human long non-coding RNAs

Expression profiles of long non-coding RNAs (lncRNAs) across diverse biological conditions provide significant insights into their biological functions, interacting targets as well as transcriptional reliability. However, there lacks a comprehensive resource that systematically characterizes the expression landscape of human lncRNAs by integrating their expression profiles across a wide range of biological conditions. Here, we present LncExpDB (https://bigd.big.ac.cn/lncexpdb), an expression database of human lncRNAs that is devoted to providing comprehensive expression profiles of lncRNA genes, exploring their expression features and capacities, identifying featured genes with potentially important functions, and building interactions with protein-coding genes across various biological contexts/conditions. Based on comprehensive integration and stringent curation, LncExpDB currently houses expression profiles of 101 293 high-quality human lncRNA genes derived from 1977 samples of 337 biological conditions across nine biological contexts. Consequently, LncExpDB estimates lncRNA genes' expression reliability and capacities, identifies 25 191 featured genes, and further obtains 28 443 865 lncRNA-mRNA interactions. Moreover, user-friendly web interfaces enable interactive visualization of expression profiles across various conditions and easy exploration of featured lncRNAs and their interacting partners in specific contexts. Collectively, LncExpDB features comprehensive integration and curation of lncRNA expression profiles and thus will serve as a fundamental resource for functional studies on human lncRNAs.

NEAT1 Decreasing Suppresses Parkinson's Disease Progression via Acting as miR-1301-3p Sponge

Long non-coding RNA (lncRNA) plays a crucial role in multiple disorders, while the role of it in Parkinson's disease (PD) is still unclear. Here, the increased lncRNA NEAT1 was discovered in MPP+-induced SH-SY5Y cells. Then, we proved that NEAT1 decreasing suppressed MPP+-induced neuronal apoptosis, upregulation of α-syn and activation of NLRP3 inflammasome. Rescue experiments shown that the inhibition of NEAT1 decreasing to MPP+-induced activation of NLRP3 inflammasome and subsequent neuronal apoptosis can be reversed by overexpressed α-syn. Subsequently, we indicated the interaction between NEAT1 and miR-1301-3p, as well as between NEAT1 and miR-5047. Interesting, we found that NEAT1 decreasing repressed the expression of GJB1, a downstream target of miR-1301-3p and miR-5047, through promoting miR-1301-3p rather than miR-5047 expression. Finally, we transfected miR-1301-3p inhibitor to MPP+-induced SH-SY5Y cells following si-NEAT1, and found that downregulation of NEAT1 repressed α-syn-mediated the activation of NLRP3 inflammasome through regulating miR-1301-3p/GJB1 signaling pathway. Overall, our data demonstrated that NEAT1 decreasing effectively suppressed MPP+-induced neuronal apoptosis. Mechanismly, downregulation of NEAT1 repressed α-syn-induced activation of NLRP3 inflammasome via inhibiting the expression of GJB1 by targeting miR-1301-3p. Our study supported a new and reliable evidence for lncRNA NEAT1 as a potential target for PD treatment.

The dual functions of the long noncoding RNA CASC15 in malignancy

Emerging evidence has demonstrated that long noncoding RNAs (lncRNAs) play vital roles in tumorigenesis and progression. LncRNAs can participate in various biological processes, such as cell growth, anti-apoptosis functions, migration, and invasion. Cancer susceptibility candidate 15 (CASC15) is a cancer-related lncRNA that has been reported to play opposite roles in the pathogenesis of different types of cancers. Studies have shown that CASC15 is downregulated in ovarian cancer and neuroblastoma, acting mainly as a tumour suppressor, while it is highly expressed and carcinogenic in hepatocellular carcinoma (HCC), lung cancer, tongue squamous cell carcinoma, gastric cancer, colorectal cancer, cervical cancer, and breast cancer. Furthermore, aberrant CASC15 expression is associated with tumorigenesis, progression, and patient outcomes via regulation of target genes and signalling pathways. In this review, we summarize current data concerning the regulatory functions and underlying mechanisms of CASC15 in tumour development. We also highlight its potential clinical utility as a biomarker for early detection or as a therapeutic target in human cancers.

LINC00494 Promotes Ovarian Cancer Development and Progression by Modulating NFκB1 and FBXO32

BACKGROUND

Ovarian cancer represents one of the most frequent gynecological cancers and is significant cause of death for women around the world. Long non-coding RNAs (lncRNAs) are recognized as critical governors of gene expression during carcinogenesis, but their effects on the occurrence and development of ovarian cancer require further investigation. In this report, we characterized LINC00494 as a novel oncogenic lncRNA in ovarian cancer.

METHODS

Bioinformatics analysis predicted potential interactions among LINC00494, NFκB1, and FBXO32 in ovarian cancer, which were tested by dual-luciferase reporter assay, RNA pull-down, RIP, and ChIP assay. Cancer cells were transfected with relevant treated plasmids, followed by scratch and Transwell assays. The treated cells were injected into nude mice to establish a xenograft model for testing effects of LINC00494 and its target gene in vivo.

RESULTS

LINC00494 and NFκB1 were highly expressed whereas FBXO32 had low expression in ovarian cancer cells and tissues. LINC00494 was found to bind NFκB1 and increase its activity, while NFκB1 was enriched at the FBXO32 promoter region, where it acted to reduce FBXO32 transcription. Overexpression of LINC00494 elevated NFκB1 expression and enhanced cell migration, invasion and tumorigenesis, but additional overexpression of FBXO32 interfered with the tumorgenicity of ovarian cancer cells in vitro and in vivo.

CONCLUSION

Our work demonstrated that LINC00494 promoted ovarian cancer progression by modulating FBXO32 via binding with the transcription factor NFκB1. These results provided new insight into the mechanism of ovarian cancer pathogenesis and suggested new therapeutic targets.

Biological Aspects of Cancer Health Disparities

Racial and ethnic disparities span the continuum of cancer care and are driven by a complex interplay among social, psychosocial, lifestyle, environmental, health system, and biological determinants of health. Research is needed to identify these determinants of cancer health disparities and to develop interventions to achieve cancer health equity. Herein, we focus on the overall burden of ancestry-related molecular alterations, the functional significance of the alterations in hallmarks of cancer, and the implications of the alterations for precision oncology and immuno-oncology. In conclusion, we reflect on the importance of estimating ancestry, improving diverse racial and ethnic participation in cancer clinical trials, and examining the intersection among determinants of cancer health disparities.

A chromatin-associated splicing isoform of OIP5-AS1 acts in cis to regulate the OIP5 oncogene

A large portion of the human genome is transcribed into long noncoding RNAs that can range from 200 nucleotides to several kilobases in length. The number of identified lncRNAs is still growing, but only a handful of them have been functionally characterized. However, it is known that the functions of lncRNAs are closely related to their subcellular localization. Cytoplasmic lncRNAs can regulate mRNA stability, affect translation and act as miRNA sponges, while nuclear-retained long noncoding RNAs have been reported to be involved in transcriptional control, chromosome scaffolding, modulation of alternative splicing and chromatin remodelling. Through these processes, lncRNAs have diverse regulatory roles in cell biology and diseases. OIP5-AS1 (also known as Cyrano), a poorly characterized lncRNA expressed antisense to the OIP5 oncogene, is deregulated in multiple cancers. We showed that one of the OIP5-AS1 splicing forms (ENST00000501665.2) is retained in the cell nucleus where it associates with chromatin, thus narrowing down the spectrum of its possible mechanisms of action. Its knockdown with antisense LNA gapmeRs led to inhibited expression of a sense partner, OIP5, strongly suggesting a functional coupling between OIP5 and ENST00000501665.2. A subsequent bioinformatics analysis followed by RAP-MS and RNA Immunoprecipitation experiments suggested its possible mode of action; in particular, we found that ENST00000501665.2 directly binds to a number of nuclear proteins, including SMARCA4, a component of the SWI/SNF chromatin remodelling complex, whose binding motif is located in the promoter of the OIP5 oncogene.

Single-Cell Profiling of Coding and Noncoding Genes in Human Dopamine Neuron Differentiation

Dopaminergic (DA) neurons derived from human pluripotent stem cells (hPSCs) represent a renewable and available source of cells useful for understanding development, developing disease models, and stem-cell therapies for Parkinson's disease (PD). To assess the utility of stem cell cultures as an in vitro model system of human DA neurogenesis, we performed high-throughput transcriptional profiling of ~20,000 ventral midbrain (VM)-patterned stem cells at different stages of maturation using droplet-based single-cell RNA sequencing (scRNAseq). Using this dataset, we defined the cellular composition of human VM cultures at different timepoints and found high purity DA progenitor formation at an early stage of differentiation. DA neurons sharing similar molecular identities to those found in authentic DA neurons derived from human fetal VM were the major cell type after two months in culture. We also developed a bioinformatic pipeline that provided a comprehensive long noncoding RNA landscape based on temporal and cell-type specificity, which may contribute to unraveling the intricate regulatory network of coding and noncoding genes in DA neuron differentiation. Our findings serve as a valuable resource to elucidate the molecular steps of development, maturation, and function of human DA neurons, and to identify novel candidate coding and noncoding genes driving specification of progenitors into functionally mature DA neurons.

Web tools to perform long non-coding RNAs analysis in oncology research

Accumulated evidence suggests that the widely expressed long-non-coding RNAs (lncRNAs) are involved in biogenesis. Some aberrant lncRNAs are closely related to pathological changes, for instance, in cancer. Both in tumorigenesis and cancer progression, depending on the interplay with cellular molecules, lncRNAs can modulate transcriptional interference, chromatin remodeling, post-translational regulation and protein modification, and further interfere with signaling pathways. Aiming to the diagnosis/ prognosis markers or potential therapeutical targets, it is important to figure out the specific mechanism and the tissue-specific expressing patterns of lncRNAs. Generally, the bioinformatics analysis is the first step. More and more in silico databases are increasing. But the existing integrative online platforms’ functions are not only having their unique features but also share some common features, which may lead to a waste of time for researchers. Here, we reviewed these web tools according to the functions. For each database, we clarified the data source, analysis method and the evidence that the analysis result is derived from. This review also illustrated examples in practical use for a specific lncRNA by these web tools. It will provide convenience for researchers to quickly choose the appropriate bioinformatics web tools in oncology studies.

Longitudinal transcriptome analyses show robust T cell immunity during recovery from COVID-19

Understanding the processes of immune regulation in patients infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is crucial for improving treatment. Here, we performed longitudinal whole-transcriptome RNA sequencing on peripheral blood mononuclear cell (PBMC) samples from 18 patients with coronavirus disease 2019 (COVID-19) during their treatment, convalescence, and rehabilitation. After analyzing the regulatory networks of differentially expressed messenger RNAs (mRNAs), microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) between the different clinical stages, we found that humoral immunity and type I interferon response were significantly downregulated, while robust T-cell activation and differentiation at the whole transcriptome level constituted the main events that occurred during recovery from COVID-19. The formation of this T cell immune response might be driven by the activation of activating protein-1 (AP-1) related signaling pathway and was weakly affected by other clinical features. These findings uncovered the dynamic pattern of immune responses and indicated the key role of T cell immunity in the creation of immune protection against this disease.

An integrative atlas of chicken long non-coding genes and their annotations across 25 tissues

Long non-coding RNAs (LNC) regulate numerous biological processes. In contrast to human, the identification of LNC in farm species, like chicken, is still lacunar. We propose a catalogue of 52,075 chicken genes enriched in LNC (http://www.fragencode.org/), built from the Ensembl reference extended using novel LNC modelled here from 364 RNA-seq and LNC from four public databases. The Ensembl reference grew from 4,643 to 30,084 LNC, of which 59% and 41% with expression ≥ 0.5 and ≥ 1 TPM respectively. Characterization of these LNC relatively to the closest protein coding genes (PCG) revealed that 79% of LNC are in intergenic regions, as in other species. Expression analysis across 25 tissues revealed an enrichment of co-expressed LNC:PCG pairs, suggesting co-regulation and/or co-function. As expected LNC were more tissue-specific than PCG (25% vs. 10%). Similarly to human, 16% of chicken LNC hosted one or more miRNA. We highlighted a new chicken LNC, hosting miR155, conserved in human, highly expressed in immune tissues like miR155, and correlated with immunity-related PCG in both species. Among LNC:PCG pairs tissue-specific in the same tissue, we revealed an enrichment of divergent pairs with the PCG coding transcription factors, as for example LHX5, HXD3 and TBX4, in both human and chicken.

The Long Non-coding RNAs: Paramount Regulators of the NLRP3 Inflammasome

The NOD LRR pyrin domain containing protein 3 (NLRP3) inflammasome is a cytosolic multi-proteins conglomerate with intrinsic ATPase activity. Their predominant presence in the immune cells emphasizes its significant role in immune response. The downstream effector proteins IL-1β and IL-18 are responsible for the biological functions of the NLRP3 inflammasome upon encountering the alarmins and microbial ligands. Although the NLRP3 inflammasome is essential for host defense during infections, uncontrolled activation and overproduction of IL-1β and IL-18 increase the risk of developing autoimmune and metabolic disorders. Emerging evidences suggest the action of lncRNAs in regulating the activity of NLRP3 inflammasome in various disease conditions. The long non-coding RNA (lncRNA) is an emerging field of study and evidence on their regulatory role in various diseases is grabbing attention. Recent studies emphasize the functions of lncRNAs in the fine control of the NLRP3 inflammasome at nuclear and cytoplasmic levels by interfering in chromatin architecture, gene transcription and translation. Recently, lncRNAs are also found to control the activity of various regulators of NLRP3 inflammasome. Understanding the precise role of lncRNA in controlling the activity of NLRP3 inflammasome helps us to design targeted therapies for multiple inflammatory diseases. The present review is a novel attempt to consolidate the substantial role of lncRNAs in the regulation of the NLRP3 inflammasome. A deeper insight on the NLRP3 inflammasome regulation by lncRNAs will help in developing targeted and beneficial therapeutics in the future.

GATA6-AS1 Regulates GATA6 Expression to Modulate Human Endoderm Differentiation

Transcriptome analysis has uncovered a series of long noncoding RNAs (lncRNAs) transcribed during cell differentiation, but how lncRNA is integrated with known transcriptional regulatory network is poorly understood. Here, we utilize human definitive endoderm differentiation as a model system and decipher the functional interaction between lncRNA and key transcriptional factor. We have identified GATA6-AS1, an lncRNA divergently transcribed from the GATA6 locus, is highly expressed during endoderm differentiation. Knockdown of GATA6-AS1 in human pluripotent stem cells has no influence on morphology and pluripotency; however, GATA6-AS1 depletion causes the deficiency of definitive endoderm differentiation. GATA6-AS1 positively regulates the expression of endoderm key factor GATA6. Further investigation shows GATA6-AS1 interacts with SMAD2/3 and activates the transcription of GATA6. In addition, overexpression of GATA6 is able to rescue the defect of endoderm differentiation due to the absence of GATA6-AS1, suggesting that GATA6 is the functional target of GATA6-AS1 during endoderm differentiation. Ultimately, our study reveals that GATA6-AS1 is necessary for human endoderm specification and reveals the underlying mechanism between GATA6-AS1 and GATA6.

Long non-coding RNA ADAMTS9-AS1 suppresses colorectal cancer by inhibiting the Wnt/β-catenin signalling pathway and is a potential diagnostic biomarker

Long non‐coding RNAs (lncRNAs) have come out as critical molecular regulators of human tumorigenesis. In this study, we sought to identify and functionally characterize lncRNAs as potential mediators of colorectal cancer progression. We screened and identified a novel lncRNA, ADAMTS9‐AS1, which was significantly decreased in colorectal cancer tissues and was correlated with clinical outcome of patients according to The Cancer Genome Atlas (TCGA) database. In addition, ADAMTS9‐AS1 regulated cell proliferation and migration both in vitro and in vivo. Bioinformatics analysis revealed that overexpression of lncRNA‐ADAMTS9‐AS1 preferentially affected genes that were linked to proliferation and migration. Mechanistically, we found that ADAMTS9‐AS1 obviously suppressed β‐catenin, suggesting that Wnt signalling pathway participates in ADAMTS9‐AS1‐mediated gene transcriptional regulation in the suppression of colorectal tumorigenesis. Finally, we found that exosomal ADAMTS9‐AS1 could serve as a diagnostic biomarker for colorectal cancer with AUC = 0.835 and 95% confidence interval = 0.777‐0.911. Our data demonstrated that ADAMTS9‐AS1 might play important roles in colorectal cancer by suppressing oncogenesis. Targeting ADAMTS9‐AS1 may have potential clinical applications in colorectal cancer prognosis and treatment as an ideal therapeutic target. Finally, exosomal lncRNA‐ADAMTS9‐AS1 is a promising, novel diagnostic biomarker for colorectal cancer.

Long noncoding RNA HCG18 up-regulates the expression of WIPF1 and YAP/TAZ by inhibiting miR-141-3p in gastric cancer

BACKGROUND

Accumulating works show that lncRNAs play critical roles in the development of gastric cancer (GC). LncRNA HLA complex group 18 (HCG18) was implicated in the progression of bladder cancer and glioma, but its role in GC is unknown.

METHODS

RT-PCR was used to detect HCG18 and miR-141-3p expression in GC specimen. GC cell lines (AGS and MKN-28) were exploited as cell model. The biological effect of HCG18 on cancer cells was probed by CCK-8, colony formation, flow cytometry, Transwell and wound-healing experiments in vitro, and subcutaneous xenotransplanted tumor model and tail vein injection model in vivo. Interaction between HCG18 and miR-141-3p was determined by bioinformatics analysis, RT-PCR, and luciferase reporter experiments. Downstream gene expression of miR-141-3p, including Wiskott-Aldrich syndrome protein interacting protein family member 1 (WIPF1), Yes associated protein 1 (YAP), and tafazzin (TAZ) were detected using Western blot.

RESULTS

HCG18 was markedly up-regulated in GC specimens, while miR-141-3p was markedly down-regulated. Down-regulation of HCG18 inhibited viability, migration, and invasion of GC cells, while miR-141-3p transfection led to opposite effect. HCG18 could down-regulate miR-141-3p through adsorbing it, and a negative association between HCG18 and miR-141-3p was found in GC specimens. HCG18 promoted WIPF1, YAP and TAZ expression, nonetheless, such influence was reversed by co-transfecting with miR-141-3p.

CONCLUSION

HCG18 was aberrantly up-regulated in GC tissues, and it indirectly regulated the activity of Hippo signaling through counteracting miR-141-3p expression.

miR-138 and miR-193 target long non-coding RNA UCA1 to inhibit cell proliferation, migration, and invasion of lung cancer

Background

Long non‐coding RNA‐urothelial carcinoma associated 1 (LncRNA‐UCA1) is a crucial oncogene that is deregulated in many types of cancers. However, the mechanism of UCA1 function, especially for its posttranscriptional regulation in lung cancer, remains unclear.

Methods

miRCode was used to predict potential miRNA candidates that might target UCA1. The targets of miR‐138 and miR‐193 on UCA1 and CDK6 were verified by luciferase reporter analysis. Western blotting was used to detect protein levels. The RNA level was evaluated using quantitative real‐time polymerase chain reaction (PCR). Proliferation, wound healing, and transwell invasion assays were performed to assess cell proliferation and invasion abilities. Correlations between miR‐138 or miR‐193 and UCA1 in lung cancer tissues was assessed using quantitative real‐time PCR.

Results

miR‐138 and miR‐193 specifically targeted and regulated lncRNA‐UCA1. MiR‐138 and miR‐193 both suppressed cell proliferation and cell cycle progression. Moreover, miR‐138 and miR‐193 inhibited cell migration and invasion. Overexpression of UCA1 reversed the proliferation, migration, and invasion suppression effects of miR‐138 or miR‐193. Furthermore, miR‐138/193 affected the expression of UCA1 downstream genes. UCA1 regulated the expression of CDK6 as a miR‐138 and miR‐193 common target. In human lung cancer tissues, our study showed a significant negative correlation between miR‐138 or miR‐193 and UCA1 in lung cancer tissues.

Conclusions

Our results demonstrated that miR‐138 and miR‐193 affect cell function by directly targeting and regulating UCA1 in lung cancer.

LncRNA PCGEM1 enhances metastasis and gastric cancer invasion through targeting of miR-129-5p to regulate P4HA2 expression

AIM

Aberrantly expressed long non-coding RNAs (lncRNAs) are critical instigators of gastric cancer (GC) progression and metastasis. The ceRNA (competing endogenous RNAs) network is well-known in modulating tumor pathological and physiological processes. This research aims to determine the more effective molecular mechanisms of lncRNA PCGEM1 (prostate cancer gene expression marker 1).

METHODS

Bioinformatics database and Ago2-RIP were performed to predict and verify the potential targets of lncRNA PCGEM1. Both gain- and loss-of-function experiments were carried out to dissect the biological functions of RNAs. Fluorescence in situ hybridization, dual-luciferase reporter assays, western blot, and real-time PCR (RT-PCR) experiments were utilized to determine the pathophysiological pathways of competitive endogenous RNAs (ceRNAs).

RESULTS

GC cells expressed high levels of cytoplasmic PCGEM1. Loss-of-function experiments displayed that the silencing of PCGEM1 suppressed metastatic and invasive cell qualities. PCGEM1 was also found to have associations with miR-129-5p. Subsequently, luciferase reporter and RIP experiments, together with RT-PCR, verified that PCGEM1 functioned as a ceRNA of P4HA2 (Prolyl 4-Hydroxylase Subunit Alpha 2) via sponging miR-129-5p to up-regulate P4HA2 expression. Finally, the rescue assays determined that P4HA2 overexpression rescued the inhibited cell invasion and metastasis caused by PCGEM1 down-regulation.

CONCLUSION

These findings found that an over-expression of PCGEM1 in GC acts as a miR-129-5p sponge, leading to higher levels of P4HA2. The PCGEM1/miR-129-5p/P4HA2 axis was confirmed to possess a crucial role in GC metastasis and invasion, suggesting its utility as a potential diagnostic and therapeutic biomarker.

Long noncoding RNAs in endometriosis: Biological functions, expressions, and mechanisms

Endometriosis refers to a benign chronic gynecological disorder, and is defined as the ectopic growth of endometrium in pelvic cavity. Endometriosis affects about 10% of reproductive-aged women. Unfortunately, the pathogenesis of endometriosis remains obscure, and the disease witnesses a lack of effective therapy approaches. Therefore, more research needs to be performed to throw light on endometriosis, its pathogenesis, and therapy. Long noncoding RNAs (lncRNAs), which are defined as functional cellular RNA longer than 200 nucleotides, have been implicated in many chronic disorders. It has been suggested that lncRNAs are closely related to the endometriosis process. Nevertheless, the molecular mechanisms by which lncRNAs associate with endometriosis should be elucidated more detailed. In our brief review, we first exhibit the aberrant lncRNAs expression in endometriosis. Then, we talk about the molecular mechanisms underlying lncRNAs in endometriosis. Finally, we also present the potential of lncRNAs as biomarkers for endometriosis.

A Panel of Four-lncRNA Signature as a Potential Biomarker for Predicting Survival in Clear Cell Renal Cell Carcinoma

Long non-coding RNAs (lncRNAs) have been considered as biomarkers for the carcinogenesis and development of various cancers. However, the prognostic significance of lncRNAs in renal cell carcinoma (RCC) remains unclear. This study aimed to determine the predictive ability of lncRNAs in clear cell RCC (ccRCC). Among the cohort of kidney renal clear cell carcinoma (KIRC) of the The Cancer Genome Atlas (TCGA), 525 patients were enrolled in our study. Expression of lncRNAs based on RNAseq was obtained from TCGA. Kaplan-Meier prognostic analysis and a Cox proportional hazards regression model were used to assess related factors. The lncRNA signature was then validated in an independent cohort of an additional 60 ccRCC patients. Hierarchical clustering of the KIRC TCGA dataset identified 26 differentially expressed lncRNAs (11 down-regulated and 15 up-regulated) using average linkage clustering. Kaplan-Meier survival analysis identified 30 statistically significant lncRNAs that strongly predicted prognosis, with 4 ccRCC-specific lncRNAs (TCL6, PVT1, MIR155HG, and HAR1B) being differentially expressed and correlating significantly with OS. Patients assigned to the high-risk group were associated with poor OS compared with patients in the low-risk group (HR = 2.57; 95%CI, 1.89-3.50; p < 0.001). This finding was validated in the Tongji Hospital cohort, and the four-lncRNA signature was shown to be significantly predictive of ccRCC prognosis (p < 0.001). In this study, we constructed an applicable four-lncRNA-based classifier as a reliable prognostic and predictive tool for OS in patients with ccRCC.

Sex differences in cancer mechanisms

We now know that cancer is many different diseases, with great variation even within a single histological subtype. With the current emphasis on developing personalized approaches to cancer treatment, it is astonishing that we have not yet systematically incorporated the biology of sex differences into our paradigms for laboratory and clinical cancer research. While some sex differences in cancer arise through the actions of circulating sex hormones, other sex differences are independent of estrogen, testosterone, or progesterone levels. Instead, these differences are the result of sexual differentiation, a process that involves genetic and epigenetic mechanisms, in addition to acute sex hormone actions. Sexual differentiation begins with fertilization and continues beyond menopause. It affects virtually every body system, resulting in marked sex differences in such areas as growth, lifespan, metabolism, and immunity, all of which can impact on cancer progression, treatment response, and survival. These organismal level differences have correlates at the cellular level, and thus, males and females can fundamentally differ in their protections and vulnerabilities to cancer, from cellular transformation through all stages of progression, spread, and response to treatment. Our goal in this review is to cover some of the robust sex differences that exist in core cancer pathways and to make the case for inclusion of sex as a biological variable in all laboratory and clinical cancer research. We finish with a discussion of lab- and clinic-based experimental design that should be used when testing whether sex matters and the appropriate statistical models to apply in data analysis for rigorous evaluations of potential sex effects. It is our goal to facilitate the evaluation of sex differences in cancer in order to improve outcomes for all patients.

NCResNet: Noncoding Ribonucleic Acid Prediction Based on a Deep Resident Network of Ribonucleic Acid Sequences

Noncoding RNA (ncRNA) is a kind of RNA that plays an important role in many biological processes, diseases, and cancers, while cannot translate into proteins. With the development of next-generation sequence technology, thousands of novel RNAs with long open reading frames (ORFs, longest ORF length > 303 nt) and short ORFs (longest ORF length ≤ 303 nt) have been discovered in a short time. How to identify ncRNAs more precisely from novel unannotated RNAs is an important step for RNA functional analysis, RNA regulation, etc. However, most previous methods only utilize the information of sequence features. Meanwhile, most of them have focused on long-ORF RNA sequences, but not adapted to short-ORF RNA sequences. In this paper, we propose a new reliable method called NCResNet. NCResNet employs 57 hybrid features of four categories as inputs, including sequence, protein, RNA structure, and RNA physicochemical properties, and introduces feature enhancement and deep feature learning policies in a neural net model to adapt to this problem. The experiments on benchmark datasets of 8 species shows NCResNet has higher accuracy and higher Matthews correlation coefficient (MCC) compared with other state-of-the-art methods. Particularly, on four short-ORF RNA sequence datasets, specifically mouse, Saccharomyces cerevisiae, zebrafish, and cow, NCResNet achieves greater than 10 and 15% improvements over other state-of-the-art methods in terms of accuracy and MCC. Meanwhile, for long-ORF RNA sequence datasets, NCResNet also has better accuracy and MCC than other state-of-the-art methods on most test datasets. Codes and data are available at https://github.com/abcair/NCResNet.

LncRNA FGD5-AS1 can be predicted as therapeutic target in oral cancer

BACKGROUND

Long non-coding RNAs (lncRNAs) have been extensively studied to participate in the carcinogenesis of various tumors. LncRNA FGD5-AS1 has been studied as an oncogene in several cancers; however, the role it plays in oral squamous cell carcinoma (OSCC) still remains unclear.

METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) was used to assess relevant RNAs expression. CCK-8 and colony formation were combined to investigate cell proliferation. Flow cytometry was implemented to test the apoptosis of cell. Wound healing assay and transwell assays were conducted to investigate cell migration and invasion. Western blot assay was conducted to measure relevant protein expression.

RESULTS

FGD5-AS1 expression was aberrantly up-regulated in OSCC tissue and cells. FDG5-AS1 up-regulation induced USP21 overexpression advances OSCC development. Knockdown of FGD5-AS1 inhibited cell growth, migration, and invasion, yet promoted apoptosis.

CONCLUSION

FGD5-AS1 regulates OSCC via competitively binding to miR-520b against USP21. It could become a potential diagnostic biomarker for OSCC.

LINC00163 inhibits the invasion and metastasis of gastric cancer cells as a ceRNA by sponging miR-183 to regulate the expression of AKAP12

BACKGROUND

Gastric cancer (GC) is the most common and aggressive cancer of the digestive system and poses a serious threat to human health. Since genes do not work alone, our aim was to elucidate the potential network of mRNAs and noncoding RNAs (ncRNAs) in this study.

METHODS

Transcriptome data of GC were obtained from TCGA. R and Perl were used to obtain the differentially expressed RNAs and construct a competing endogenous RNA (ceRNA) regulatory network. To investigate the biological functions of differentially expressed RNAs, loss-of-function and gain-of-function experiments were performed. Real-time PCR (RT-qPCR), western blot analysis, dual-luciferase reporter assays and fluorescence in situ hybridization were conducted to explore the underlying mechanisms of competitive endogenous RNAs (ceRNAs).

RESULTS

Based on TCGA data and bioinformatics analysis, we identified the LINC00163/miR-183/A-Kinase Anchoring Protein 12 (AKAP12) axis. We observed that AKAP12 was weakly expressed in GC and suppressed invasion and metastasis in GC cells, which could be abolished by miR-183. In addition, LINC00163 can be used as a ceRNA to inhibit the expression of miR-183, thus enhancing the anticancer effect of AKAP12.

CONCLUSION

Our results demonstrated that weak LINC00163 expression in GC can sponge miR-183 to promote AKAP12. We established that the LINC00163/miR-183/AKAP12 axis plays an important role in GC invasion and metastasis and may be a potential biomarker and target for GC treatment.