LincRNAs MONC and MIR100HG act as oncogenes in acute megakaryoblastic leukemia

Exosomal lncRNA Mir100hg from lung cancer stem cells activates H3K14 lactylation to enhance metastatic activity in non-stem lung cancer cells

The mean survival of metastatic lung adenocarcinoma is less than 1 year, highlighting the urgent need to understand the mechanisms underlying its high mortality rate. The role of Extracellular vesicles (EVs) in facilitating the interactions between cancer cells and the metastatic microenvironment has garnered increasing attention. Previous studies on the role of EVs in metastasis have been primarily focused on cancer cell-derived EVs in modulating the functions of stromal cells. However, whether cancer stem cells (CSCs) can alter the metastatic properties of non-CSC cells, and whether EV crosstalk can mediate such interaction, have not been demonstrated prior to this report. In the present study, we integrated multi-omics sequencing and public database analysis with experimental validation to demonstrate, for the first time, the exosomal Mir100hg, derived from CSCs, could enhance the metastatic potential of non-CSCs both in vitro and in vivo. Mechanistically, HNRNPF and HNRNPA2B1 directly binds to Mir100hg, facilitating its trafficking via exosomes to non-CSCs. In non-CSCs, Mir100hg upregulates ALDOA expression, subsequently leading to elevated lactate production. Consequently, the increased lactate levels enhance H3K14 lactylation by 2.5-fold and promote the transcription of 169 metastasis-related genes. This cascade of events ultimately results in enhanced ALDOA-driven glycolysis and histone lactylation-mediated metastatic potential of non-CSC lung cancer cells. We have delineated a complex regulatory network utilized by CSCs to transfer their high metastatic activity to non-CSCs through exosomal Mir100hg, providing new mechanistic insights into the communication between these two heterogeneous tumor cell populations. These mechanistic insights provide novel therapeutic targets for metastatic lung cancer, including HNRNPF/HNRNPA2B1-mediated Mir100hg trafficking and the histone lactylation pathway, advancing our understanding of CSC-mediated metastasis while suggesting promising strategies for clinical intervention.

A complete sojourn on exosomes: Potential diagnostic and therapeutic agents

Exosomes are vesicles produced by the human body for carrying certain information from one cell to another. The carriers are nanosized vesicles carrying a wide variety of cargo like RNA, DNA, and proteins. Exosomes are also being used in the early diagnosis of various diseases and disorders. Current research focuses on exosomes tailoring for achieving therapeutic potential in various diseases and disorders. Besides this, their biocompatibility, stability, adjustable efficacy, and targeting properties make them attractive vehicles for formulation developers. Various preclinical studies suggested that the exosome culture cells are also modified with certain genes to achieve the desirable properties of resultant exosomes. The human body also produces some other vesicles like Ectosomes and Exomeres produced along with exosomes. Additionally, vesicles like Migrasomes are produced by migrating cells and apoptotic bodies, and Oncosomes are produced by cancer cells which can also be useful for the diagnosis of various diseases and disorders. For the separation of desired exosomes from other vesicles some latest techniques that can be useful viz differential centrifugation, density gradient centrifugation, and immunoaffinity purification have been discussed. Briefly, this review summarized various techniques of isolation of purified exosomes along with an overview of the application of exosomes in various neurodegenerative disorders and cancer along with various latest aspects of exosomes in disease progression and management which might be beneficial for the researchers.

Exosomal lncRNA Mir100hg derived from cancer stem cells enhance glycolysis and promote metastasis of melanoma through miR-16-5p and miR-23a-3p

Increasing evidence demonstrate that the significant role of long non-coding RNA (lncRNA) in metastasis and the remodeling of the tumor microenvironment. However, the precise mechanisms of lncRNAs in cancer metastasis are still poorly understood. The function of lncRNA-Mir100hg in melanoma and its involvement in mediating communication between tumor stem cells and non-stemness tumor cells remains unknown. We found that Mir100hg is upregulated in melanoma stem cells (CSCs) known as OLSD. Furthermore, Mir100hg can be transferred from OLSD to non-stem cancer cells (OL) through exosomes. Once Mir100hg enters OL cells, it operates through a competitive endogenous RNA (ceRNA) mechanism. It competes with microRNAs (miR-16-5p and miR-23a-3p) by binding to them, thus preventing these miRNAs from targeting their mRNAs. As a result, the expression of glycolysis-related mRNA was restored. This ultimately enhances the metastatic capability of OL cells. In summary, our study uncovers a network used by CSCs to transfer their high metastatic activity to non-stem cancer cells through the exosomal Mir100hg. This mechanism sheds new light on the communication between heterogeneous cancer cell populations in melanoma. Importantly, it provides novel insights into the role of lncRNAs in cancer metastasis and highlights the significance of the tumor microenvironment in facilitating metastasis.

RUNX1::MIR99AHG Chimera in Acute Myeloid Leukemia

RUNX1 fuses with over 70 different partner genes in hematological neoplasms. While common RUNX1 chimeras have been extensively studied and their prognosis is well established, our current understanding of less common RUNX1 chimeras is limited. Here, we present a case of acute myeloid leukemia (AML) with a rare RUNX1 chimera. Bone marrow cells obtained at diagnosis from a 71-year-old patient diagnosed with AML-M5 were studied using G-banding, fluorescence in situ hybridization, array comparative genomic hybridization, RNA sequencing, PCR, and Sanger sequencing. Combined findings from the abovementioned assays suggested three cytogenetic clones: one with a normal karyotype, one with inv(21)(q21q22), and one with two inv(21)(q21q22). The molecular analysis revealed the fusion of RUNX1 with MIR99AHG (at 21q21.1), further supporting the presence of an inv(21)(q21q22). The present case is the third reported AML harboring a RUNX1::MIR99AHG chimera. Similar to the two previously described AML patients, our case also had an FLT3 aberration.

Transfer of miR-100 and miR-125b increases 3D growth and invasiveness in recipient cancer cells

Aim

Extracellular communication via the transfer of vesicles and nanoparticles is now recognized to play an important role in tumor microenvironment interactions. Cancer cells upregulate and secrete abundant levels of miR-100 and miR-125b that can alter gene expression in donor and recipient cells. In this study, we sought to identify targets of miR-100 and miR-125b and conclusively demonstrate that microRNAs (miRNAs) can be functionally transferred from donor to recipient cells.

Methods

To identify targets of miR-100 and miR-125b, we used bioinformatic approaches comparing multiple colorectal cancer (CRC) cell lines, including knockout lines lacking one or both of these miRNAs. We also used spheroid and 3D growth conditions in collagen to test colony growth and invasiveness. We also used Transwell co-culture systems to demonstrate functional miRNA transfer.

Results

From an initial list of 96 potential mRNA targets, we identified and tested 15 targets, with 8 showing significant downregulation in the presence of miR-100 and miR-125b. Among these, cingulin (CGN) and protein tyrosine phosphatase receptor type-R (PTPRR) are downregulated in multiple cancers, consistent with regulation by increased levels of miR-100 and miR-125b. We also show that increased cellular levels of miR-100 and miR-125b enhance 3D growth and invasiveness in CRC and glioblastoma cell lines. Lastly, we demonstrate that extracellular transfer of miR-100 and miR-125b can silence both reporter and endogenous mRNA targets in recipient cells and also increase the invasiveness of recipient spheroid colonies when grown under 3D conditions in type I collagen.

Conclusion

miR-100 and miR-125b target multiple mRNAs that can regulate 3D cell-autonomous growth and invasiveness. By extracellular transfer, miR-100 and miR-125b can also increase colony growth and invasiveness in recipient cells through non-cell-autonomous mechanisms.

A 69 long noncoding RNA signature predicts relapse and acts as independent prognostic factor in pediatric AML

ABSTRACT

Risk stratification using genetics and minimal residual disease has allowed for an increase in the cure rates of pediatric acute myeloid leukemia (pedAML) to up to 70% in contemporary protocols. Nevertheless, ∼30% of patients still experience relapse, indicating a need to optimize stratification strategies. Recently, long noncoding RNA (lncRNA) expression has been shown to hold prognostic power in multiple cancer types. Here, we aimed at refining relapse prediction in pedAML using lncRNA expression. We built a relapse-related lncRNA prognostic signature, named AMLlnc69, using 871 transcriptomes of patients with pedAML obtained from the Therapeutically Applicable Research to Generate Effective Treatments repository. We identified a 69 lncRNA signature AMLlnc69 that is highly predictive of relapse risk (c-index = 0.73), with area under the receiver operating characteristic curve (AUC) values for predicting the 1-, 2-, and 3-year relapse-free survival (RFS) of 0.78, 0.77, and 0.77, respectively. The internal validation using a bootstrap method (resampling times = 1000) resulted in a c-index of 0.72 and AUC values for predicting the 1-, 2-, and 3-year RFS of 0.77, 0.76, and 0.76, respectively. Through a Cox regression analysis, AMLlnc69, nucleophosmin mutation, and white blood cell at diagnosis were identified as independent predictors of RFS. Finally, a nomogram was build using these 2 parameters, showing a c-index of 0.80 and 0.71 after bootstrapping (n = 1000). In conclusion, the identified AMLlnc69 will, after prospective validation, add important information to guide the management of patients with pedAML. The nomogram is a promising tool for easy stratification of patients into a novel scheme of relapse-risk groups.

miR-100 and miR-125b Contribute to Enhanced 3D Growth and Invasiveness and can be Functionally Transferred to Silence Target Genes in Recipient Cells

Extracellular communication via the transfer of vesicles and nanoparticles is now recognized to play an important role in tumor microenvironment interactions. Cancer cells upregulate and secrete abundant levels of miR-100 and miR-125b that can alter gene expression by both cell- and non-cell-autonomous mechanisms. We previously showed that these miRNAs activate Wnt signaling in colorectal cancer (CRC) through noncanonical pairing with 5 negative regulators of Wnt signaling. To identify additional targets of miR-100 and miR-125b , we used bioinformatic approaches comparing multiple CRC cell lines, including knockout lines lacking one or both of these miRNAs. From an initial list of 96 potential mRNA targets, we tested 15 targets with 8 showing significant downregulation in the presence of miR-100 and miR-125b . Among these, Cingulin (CGN) and Protein tyrosine phosphatase receptor type-R (PTPRR) are downregulated in multiple cancers, consistent with regulation by increased levels of miR-100 and miR-125b. We also show that increased cellular levels of miR-100 and miR-125b enhance 3D growth and invasiveness in CRC and glioblastoma cell lines. Lastly, we demonstrate that extracellular transfer of miR-100 and miR-125b can silence both reporter and endogenous mRNA targets in recipient cells and also increase the invasiveness of recipient spheroid colonies when grown under 3D conditions in type I collagen.

Molecular detection of exosomal miRNAs of blood serum for prognosis of colorectal cancer

Colorectal cancer (CRC) is the third most common cancer affecting people. The discovery of new, non-invasive, specific, and sensitive molecular biomarkers for CRC may assist in the diagnosis and support therapeutic decision making. Exosomal miRNAs have been demonstrated in carcinogenesis and CRC development, which makes these miRNAs strong biomarkers for CRC. Deep sequencing allows a robust high-throughput informatics investigation of the types and abundance of exosomal miRNAs. Thus, exosomal miRNAs can be efficiently examined as diagnostic biomarkers for disease screening. In the present study, a number of 660 mature miRNAs were detected in patients diagnosed with CRC at different stages. Of which, 29 miRNAs were differentially expressed in CRC patients compared with healthy controls. Twenty-nine miRNAs with high abundance levels were further selected for subsequent analysis. These miRNAs were either highly up-regulated (e.g., let-7a-5p, let-7c-5p, let-7f-5p, let-7d-3p, miR-423-5p, miR-3184-5p, and miR-584) or down-regulated (e.g., miR-30a-5p, miR-99-5p, miR-150-5p, miR-26-5p and miR-204-5p). These miRNAs influence critical genes in CRC, leading to either tumor growth or suppression. Most of the reported diagnostic exosomal miRNAs were shown to be circulating in blood serum. The latter is a novel miRNA that was found in exosomal profile of blood serum. Some of the predicted target genes of highly expressed miRNAs participate in several cancer pathways, including CRC pathway. These target genes include tumor suppressor genes, oncogenes and DNA repair genes. Main focus was given to multiple critical signaling cross-talking pathways including transforming growth factor β (TGFβ) signaling pathways that are directly linked to CRC. In conclusion, we recommend further analysis in order to experimentally confirm exact relationships between selected differentially expressed miRNAs and their predicted target genes and downstream functional consequences.

Competing Endogenous RNAs Crosstalk in Hippocampus: A Potential Mechanism for Neuronal Developing Defects in Down Syndrome

Down syndrome (DS) is the most example of aneuploidy, resulting from an additional copy of all or part of chromosome 21. Competing endogenous RNAs (ceRNAs) play important roles in neuronal development and neurological defects. This study aimed to identify hub genes and synergistic crosstalk among ceRNAs in the DS fetal hippocampus as potential targets for the treatment of DS-related neurodegenerative diseases. We profiled differentially expressed long non-coding RNAs (DElncRNAs), differentially expressed circular RNAs (DEcircRNAs), differentially expressed microRNAs (DEmiRNAs), and differentially expressed messenger RNAs (DEmRNAs) in hippocampal samples from patients with or without DS. Functional enrichment analysis and gene set enrichment analysis were performed, and chromosome 21-related ceRNA and protein-protein interaction networks were constructed. Additionally, the correlations between lncRNA-mRNA and miRNA-mRNA expression in the samples and HEK293T cells were validated. Our finding of changes in the expression of some key genes and ncRNAs on chromosome 21 in DS might not fully conform to the gene dosage hypothesis. Moreover, we found that four lncRNAs (MIR99AHG, PLCB4, SNHG14, GIGYF2) and one circRNA (hsa_circ_0061697) may competitively bind with three miRNAs (hsa-miR-548b-5p, miR-730-5p, and hsa-miR-548i) and subsequently regulate five mRNAs (beta-1,3-galactosyltransferase 5 [B3GALT5], helicase lymphoid-specific [HELLS], thrombospondin-2 [THBS2], glycinamide ribonucleotide transformylase [GART], clathrin heavy chain like 1 [CLTCL1]). These RNAs, whether located on chromosome 21 or not, interact with each other and might activate the PI3K/Akt/mTOR and Wnt signaling pathways, which are involved in autophagosome formation and tau hyperphosphorylation, possibly leading to adverse consequences of trisomy 21. These findings provide researchers with a better understanding of the fundamental molecular mechanisms underlying DS-related progressive defects in neuronal development.

miR-125 in Breast Cancer Etiopathogenesis: An Emerging Role as a Biomarker in Differential Diagnosis, Regenerative Medicine, and the Challenges of Personalized Medicine

Breast Cancer (BC) is one of the most common cancer types worldwide, and it is characterized by a complex etiopathogenesis, resulting in an equally complex classification of subtypes. MicroRNA (miRNA or miR) are small non-coding RNA molecules that have an essential role in gene expression and are significantly linked to tumor development and angiogenesis in different types of cancer. Recently, complex interactions among coding and non-coding RNA have been elucidated, further shedding light on the complexity of the roles these molecules fulfill in cancer formation. In this context, knowledge about the role of miR in BC has significantly improved, highlighting the deregulation of these molecules as additional factors influencing BC occurrence, development and classification. A considerable number of papers has been published over the past few years regarding the role of miR-125 in human pathology in general and in several types of cancer formation in particular. Interestingly, miR-125 family members have been recently linked to BC formation as well, and complex interactions (competing endogenous RNA networks, or ceRNET) between this molecule and target mRNA have been described. In this review, we summarize the state-of-the-art about research on this topic.

Graph Reasoning Method Based on Affinity Identification and Representation Decoupling for Predicting lncRNA-Disease Associations

An increasing number of studies have shown that dysregulation of lncRNAs is related to the occurrence of various diseases. Most of the previous methods, however, are designed based on homogeneity assumption that the representation of a target lncRNA (or disease) node should be updated by aggregating the attributes of its neighbor nodes. However, the assumption ignores the affinity nodes that are far from the target node. We present a novel prediction method, GAIRD, to fully leverage the heterogeneous information in the network and the decoupled node features. The first major innovation is a random walk strategy based on width-first searching and depth-first searching. Different from previous methods that only focus on homogeneous information, our new strategy learns both the homogeneous information within local neighborhoods and the heterogeneous information within higher-order neighborhoods. The second innovation is a representation decoupling module to extract the purer attributes and the purer topologies. Third, a module based on group convolution and deep separable convolution is developed to promote the pairwise intrachannel and interchannel feature learning. The experimental results show that GAIRD outperforms comparing state-of-the-art methods, and the ablation studies prove the contributions of major innovations. We also performed case studies on 3 diseases to further demonstrate the effectiveness of the GAIRD model in applications.

The long non-coding RNA OTX2-AS1 promotes tumor growth and predicts response to BCL-2 inhibition in medulloblastoma

PURPOSE

Primary brain tumors are a leading cause of cancer-related death in children, and medulloblastoma is the most common malignant pediatric brain tumor. The current molecular characterization of medulloblastoma is mainly based on protein-coding genes, while little is known about the involvement of long non-coding RNAs (lncRNAs). This study aimed to elucidate the role of the lncRNA OTX2-AS1 in medulloblastoma.

METHODS

Analyses of DNA copy number alterations, methylation profiles, and gene expression data were used to characterize molecular alterations of OTX2-AS1 in medulloblastoma tissue samples. In vitro analyses of medulloblastoma cell models and orthotopic in vivo experiments were carried out for functional characterization of OTX2-AS1. High-throughput drug screening was employed to identify pharmacological inhibitors, while proteomics and metabolomics analyses were performed to address potential mechanisms of drug action.

RESULTS

We detected amplification and consecutive overexpression of OTX2 and OTX2-AS1 in a subset of medulloblastomas. In addition, OTX2-AS1 promoter methylation was linked to OTX2-AS1 expression. OTX2-AS1 knockout reduced medulloblastoma cell viability and cell migration in vitro and prolonged survival in the D283 orthotopic medulloblastoma mouse xenograft model. Pharmacological inhibition of BCL-2 suppressed the growth of OTX2-AS1 overexpressing medulloblastoma cells in vitro.

CONCLUSIONS

Our study revealed a pro-tumorigenic role of OTX2-AS1 in medulloblastoma and identified BCL-2 inhibition as a potential therapeutic approach to target OTX2-AS1 overexpressing medulloblastoma cells.

Integrative Genomic Analyses Identify LncRNA Regulatory Networks across Pediatric Leukemias and Solid Tumors

Long noncoding RNAs (lncRNA) play an important role in gene regulation and contribute to tumorigenesis. While pan-cancer studies of lncRNA expression have been performed for adult malignancies, the lncRNA landscape across pediatric cancers remains largely uncharted. Here, we curated RNA sequencing data for 1,044 pediatric leukemia and extracranial solid tumors and integrated paired tumor whole genome sequencing and epigenetic data in relevant cell line models to explore lncRNA expression, regulation, and association with cancer. A total of 2,657 lncRNAs were robustly expressed across six pediatric cancers, including 1,142 exhibiting histotype-elevated expression. DNA copy number alterations contributed to lncRNA dysregulation at a proportion comparable to protein coding genes. Application of a multidimensional framework to identify and prioritize lncRNAs impacting gene networks revealed that lncRNAs dysregulated in pediatric cancer are associated with proliferation, metabolism, and DNA damage hallmarks. Analysis of upstream regulation via cell type-specific transcription factors further implicated distinct histotype-elevated and developmental lncRNAs. Integration of these analyses prioritized lncRNAs for experimental validation, and silencing of TBX2-AS1, the top-prioritized neuroblastoma-specific lncRNA, resulted in significant growth inhibition of neuroblastoma cells, confirming the computational predictions. Taken together, these data provide a comprehensive characterization of lncRNA regulation and function in pediatric cancers and pave the way for future mechanistic studies.

SIGNIFICANCE

Comprehensive characterization of lncRNAs in pediatric cancer leads to the identification of highly expressed lncRNAs across childhood cancers, annotation of lncRNAs showing histotype-specific elevated expression, and prediction of lncRNA gene regulatory networks.

Exosomal lncRNA Mir100hg derived from cancer stem cells enhance glycolysis and promote metastasis of lung adenocarcinoma through mircroRNA-15a-5p/31-5p

BACKGROUND

Exosomes are a new class of molecular entities in the metastatic microenvironment, which can mediate bidirectional communication between cells. While exosomes-mediated interactions between tumor cells and other cell populations in the tumor microenvironment have attracted most attention, little is known about the significance of exosomes in mediating the interaction between non-stemness cancer cells and cancer stem cells during cancer progression.

METHODS

The structure, sequence and downstream target miRNAs of lncRNA Mir100hg were predicted by online web resources. The bioinformatics prediction results were validated with experimental verification: exosome tracing, electron microscopy, Luciferase assay, metabolomics sequencing and mouse tail vein model of pulmonary metastasis. A complex regulatory network of "cancer stem cells-exosomal lncRNA-non-stem cancer cells" was constructed.

RESULTS

This study demonstrates firstly that lncRNA Mir100hg is upregulated in lung cancer stem cell LLC-SD (Lung cancer stem cells) and can be delivered to non-stemness cancer cells LLC (Lewis lung cancer cells) via exosomes. In LLC, Mir100hg targets miR-15a-5p and miR-31-5p which leads to the increase of the global glycolytic activity of lung cancer cells and consequently, the enhancement of their metastatic capability.

CONCLUSION

We delineated a complex regulatory network that utilized by cancer stem cells to transfer their high metastatic activity to the low-metastatic non-stemness cancer cells through exosomal Mir100hg, thereby providing new mechanistic insights into the communication between two heterogeneous tumor cells. Video Abstract.

The lncRNA MIR99AHG directs alternative splicing of SMARCA1 by PTBP1 to enable invadopodia formation in colorectal cancer cells

Alternative splicing regulates gene expression and functional diversity and is often dysregulated in human cancers. Here, we discovered that the long noncoding RNA (lncRNA) MIR99AHG regulated alternative splicing to alter the activity of a chromatin remodeler and promote metastatic behaviors in colorectal cancer (CRC). MIR99AHG was abundant in invasive CRC cells and metastatic tumors from patients and promoted motility and invasion in cultured CRC cells. MIR99AHG bound to and stabilized the RNA splicing factor PTBP1, and this complex increased cassette exon inclusion in the mRNA encoding the chromatin remodeling gene SMARCA1. Specifically, MIR99AHG altered the nature of PTBP1 binding to the splice sites on intron 12 of SMARCA1 pre-mRNA, thereby triggering a splicing switch from skipping to including exon 13 to produce the long isoform, SMARCA1-L. SMARCA1, but not SMARCA1-L, suppressed invadopodia formation, cell migration, and invasion. Analysis of CRC samples revealed that the abundance of MIR99AHG transcript positively correlated with that of SMARCA1-L mRNA and PTBP1 protein and with poor prognosis in patients with CRC. Furthermore, TGF-β1 secretion from cancer-associated fibroblasts increased MIR99AHG expression in CRC cells. Our findings identify an lncRNA that is induced by cues from the tumor microenvironment and that interacts with PTBP1 to regulate alternative splicing, potentially providing a therapeutic target and predictive biomarker for metastatic CRC.

Transcriptional repression of lncRNA and miRNA subsets mediated by LRF during erythropoiesis

Non-coding RNA (ncRNA) species, mainly long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been currently imputed for lesser or greater involvement in human erythropoiesis. These RNA subsets operate within a complex circuit with other epigenetic components and transcription factors (TF) affecting chromatin remodeling during cell differentiation. Lymphoma/leukemia-related (LRF) TF exerts higher occupancy on DNA CpG rich sites and is implicated in several differentiation cell pathways and erythropoiesis among them and also directs the epigenetic regulation of hemoglobin transversion from fetal (HbF) to adult (HbA) form by intervening in the γ-globin gene repression. We intended to investigate LRF activity in the evolving landscape of cells' commitment to the erythroid lineage and specifically during HbF to HbA transversion, to qualify this TF as potential repressor of lncRNAs and miRNAs. Transgenic human erythroleukemia cells, overexpressing LRF and further induced to erythropoiesis, were subjected to expression analysis in high LRF occupancy genetic loci-producing lncRNAs. LRF abundance in genetic loci transcribing for studied lncRNAs was determined by ChIP-Seq data analysis. qPCRs were performed to examine lncRNA expression status. Differentially expressed miRNA pre- and post-erythropoiesis induction were assessed by next-generation sequencing (NGS), and their promoter regions were charted. Expression levels of lncRNAs were correlated with DNA methylation status of flanked CpG islands, and contingent co-regulation of hosted miRNAs was considered. LRF-binding sites were overrepresented in LRF overexpressing cell clones during erythropoiesis induction and exerted a significant suppressive effect towards lncRNAs and miRNA collections. Based on present data interpretation, LRF's multiplied binding capacity across genome is suggested to be transient and associated with higher levels of DNA methylation. KEY MESSAGES: During erythropoiesis, LRF displays extensive occupancy across genetic loci. LRF significantly represses subsets of lncRNAs and miRNAs during erythropoiesis. Promoter region CpG islands' methylation levels affect lncRNA expression. MiRNAs embedded within lncRNA loci show differential regulation of expression.

A concise review on the role of MIR100HG in human disorders

MIR100HG is a long non-coding RNA (lncRNA) encoded by a locus on chr11:122,028,203-122,556,721. This gene can regulate cell proliferation, apoptosis, cell cycle transition and cell differentiation. MIR100HG was firstly identified through a transcriptome analysis and found to regulate differentiation of human neural stem cells. It is functionally related with a number of signalling pathways such as TGF-β, Wnt, Hippo and ERK/MAPK signalling pathways. Dysregulation of MIR100HG has been detected in a diversity of cancers in association with clinical outcomes. Moreover, it has a role in the pathophysiology of dilated cardiomyopathy, intervertebral disk degeneration and pulmonary fibrosis. The current study summarizes the role of these lncRNAs in human disorders.

Integrated analysis of competitive endogenous RNA networks in elder patients with non-small cell lung cancer

BACKGROUND

Lung cancer is one of the most prevalent cancers and the leading cause of cancer-related deaths worldwide; non-small cell lung cancer (NSCLC) comprises approximately 80% of all lung cancer cases. This study aimed to construct a competing endogenous RNA (ceRNA) network and identify prognostic signatures in elderly patients with NSCLC.

METHODS

We extracted data from elderly patients with NSCLC from The Cancer Genome Atlas and identified differentially expressed (DE) messenger RNAs (mRNAs), microRNAs (miRNAs), and long non-coding RNAs (lncRNAs). Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were performed to investigate the functions of DEmRNAs. The interactions between RNAs were predicted using starBase, TargetScan, miRTarBase, and miRanda. Cytoscape version 3.0 was used to construct and visualize the lncRNA-miRNA-mRNA ceRNA network. The association between the expression levels of DERNAs in the constructed ceRNA network and overall survival was determined using the survival package in R software. Furthermore, another Gene Expression Omnibus cohort was studied to externally validate the ceRNA network.

RESULTS

In total, 2865 DEmRNAs, 62 DEmiRNAs, and 131 DElncRNAs were identified. Dysregulated mRNAs are enriched in cancer-related processes and pathways. A ceRNA network was constructed using 38 miRNAs, 61 lncRNAs, and 164 mRNAs. Of these, 3 lncRNAs, 3 miRNAs, and 16 mRNAs were closely related to overall survival. The MIR99AHG-hsa-miR-31-5p-PRKCE axis has been identified as a potential ceRNA network involved in the development of NSCLC in elderly individuals. External validation of the MIR99AHG-hsa-miR-31-5p-PRKCE axis in the GSE19804 cohort showed that PRKCE was downregulated and that MIR99AHG was upregulated in the tumor tissues of elderly patients with NSCLC compared with normal lung tissues.

CONCLUSIONS

This study provides novel insights into the lncRNA-miRNA-mRNA ceRNA network and reveals potential biomarkers for the diagnosis and prognosis of elderly patients with NSCLC.

METTL3-mediated long non-coding RNA MIR99AHG methylation targets miR-4660 to promote bone marrow mesenchymal stem cell osteogenic differentiation

Whether long non-coding RNA Mir-99a-Let-7c Cluster Host Gene (LncRNA MIR99AHG) is involved in osteoporosis (OP) remains vague, so we hereby center on its implication. Old C57BL/6J mice were injected with the silencing lentivirus of MIR99AHG and subjected to microCT analysis and immunohistochemistry on osteogenic cells. The osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) with or without transfection was determined by alkaline phosphatase (ALP) and Alizarin Red S staining. Total N(6)-methyladenosine (m6A) on the bone marrow mesenchymal stem cells (BMSCs) was quantified. The potential methylation site and the complementary binding sites with candidate microRNA (miR) were predicted via bioinformatic analyses, with the latter being confirmed via dual-luciferase reporter, RNA immunoprecipitation and RNA pull-down assays. Quantitative real-time PCR and Western blot were used for quantification assays. MIR99AHG was decreased during the osteogenic differentiation of BMSCs, where increased Osterix (OSX), Collagen, Type I, Alpha 1 (Col1A1), Osteocalcin (OCN) and RUNX Family Transcription Factor 2 (RUNX2) as well as more color-stained areas were found. Also, silencing MIR99AHG relieved the OP in mice and reduced the loss of osteogenic cells. M6A methylation in undifferentiated BMSCs was low and MIR99AHG overexpression abolished the effects of overexpressed METTL3 on promoting osteogenic differentiation. MiR-4660, which was downregulated in BMSCs without differentiation but increased during osteogenic differentiation, could bind with MIR99AHG. Furthermore, miR-4660 promoted osteogenic differentiation and reversed the effects of overexpressed MIR99AHG. The present study demonstrated that METTL3-mediated LncRNA MIR99AHG methylation enhanced the osteogenic differentiation of BMSCs via targeting miR-4660.

MiR-100 rs1834306 A>G Increases Biliary Atresia Risk in Southern Han Chinese Children

Background

Biliary atresia (BA) is a type of severe cholestatic childhood disease that may have a genetic component. miR-100 plays a key role in regulating cell apoptosis, proliferation, and inflammatory reactions. A single-nucleotide polymorphism in miR-100 has been proven to modulate susceptibility to various diseases.

Methods

We conducted a case-control retrospective study to explore the correlation between miR-100 gene polymorphism (rs1834306 A>G) and biliary atresia susceptibility in 484 Chinese patients and 1445 matched control subjects.

Results

Our results showed that rs1834306 A>G was correlated with a significantly increased risk for BA (GG vs. AA: adjusted odds ratio (OR) = 1.44, 95%confidence interval (CI) = 1.02-2.03, p = 0.041; and GG vs. AA/AG: adjusted OR = 1.39, 95%CI = 1.02-1.89, p = 0.036).

Conclusions

Our results showed that the rs1834306 A>G polymorphism is associated with an increased risk for BA and contributes to BA susceptibility.

The lncRNA LUCAT1 is elevated in inflammatory disease and restrains inflammation by regulating the splicing and stability of NR4A2

The nuclear long non-coding RNA LUCAT1 has previously been identified as a negative feedback regulator of type I interferon and inflammatory cytokine expression in human myeloid cells. Here, we define the mechanistic basis for the suppression of inflammatory gene expression by LUCAT1. Using comprehensive identification of RNA-binding proteins by mass spectrometry as well as RNA immunoprecipitation, we identified proteins important in processing and alternative splicing of mRNAs as LUCAT1-binding proteins. These included heterogeneous nuclear ribonucleoprotein C, M, and A2B1. Consistent with this finding, cells lacking LUCAT1 have altered splicing of selected immune genes. In particular, upon lipopolysaccharide stimulation, the splicing of the nuclear receptor 4A2 (NR4A2) gene was particularly affected. As a consequence, expression of NR4A2 was reduced and delayed in cells lacking LUCAT1. NR4A2-deficient cells had elevated expression of immune genes. These observations suggest that LUCAT1 is induced to control the splicing and stability of NR4A2, which is in part responsible for the anti-inflammatory effect of LUCAT1. Furthermore, we analyzed a large cohort of patients with inflammatory bowel disease as well as asthma and chronic obstructive pulmonary disease. In these patients, LUCAT1 levels were elevated and in both diseases, positively correlated with disease severity. Collectively, these studies define a key molecular mechanism of LUCAT1-dependent immune regulation through post-transcriptional regulation of mRNAs highlighting its role in the regulation of inflammatory disease.

Long Non-Coding RNAs as Cellular Metabolism and Haematopoiesis Regulators

Long non-coding RNAs (lncRNAs) are a category of non-coding RNAs (ncRNAs) that are more than 200 bases long and play major regulatory roles in a wide range of biologic processes, including hematopoeisis and metabolism. Metabolism in cells is an immensely complex process that involves the interconnection and unification of numerous signaling pathways. A growing body of affirmation marks that lncRNAs do participate in metabolism, both directly and indirectly, via metabolic regulation of enzymes and signaling pathways, respectively. The complexities are disclosed by the latest studies demonstrating how lncRNAs could indeed alter tissue-specific metabolism. We have entered a new realm for discovery that is both intimidating and intriguing. Understanding the different functions of lncRNAs in various cellular pathways aids in the advancement of predictive and therapeutic capabilities for a wide variety of myelodysplastic and metabolic disorders. This review has tried to give an overview of the different ncRNAs and their effects on hematopoiesis and metabolism. We have focused on the pathway of action of several lncRNAs and have also delved into their prognostic value. Their use as biomarkers and possible therapeutic targets has also been discussed. SIGNIFICANCE STATEMENT: This review has tried to give an overview of the different ncRNAs and their effects on hematopoiesis and metabolism. The pathway of action of several lncRNAs and their prognostic value was discussed. Their use as biomarkers and possible therapeutic targets has also been elaborated.

Host-Directed Targeting of LincRNA-MIR99AHG Suppresses Intracellular Growth of Mycobacterium tuberculosis

Tuberculosis (TB) caused by Mycobacterium tuberculosis (Mtb) kills 1.6 million people worldwide every year, and there is an urgent need for targeting host-pathogen interactions as a strategy to reduce mycobacterial resistance to current antimicrobials. Noncoding RNAs are emerging as important regulators of numerous biological processes and avenues for exploitation in host-directed therapeutics. Although long noncoding RNAs (lncRNAs) are abundantly expressed in immune cells, their functional role in gene regulation and bacterial infections remains understudied. In this study, we identify an immunoregulatory long intergenic noncoding RNA, lincRNA-MIR99AHG, which is upregulated in mouse and human macrophages upon IL-4/IL-13 stimulation and downregulated after clinical Mtb HN878 strain infection and in peripheral blood mononuclear cells from active TB patients. To evaluate the functional role of lincRNA-MIR99AHG, we used antisense locked nucleic acid (LNA) GapmeR-mediated antisense oligonucleotide (ASO) lncRNA knockdown experiments. Knockdown of lincRNA-MIR99AHG with ASOs significantly reduced intracellular Mtb growth in mouse and human macrophages and reduced pro-inflammatory cytokine production. In addition, in vivo treatment of mice with MIR99AHG ASOs reduced the mycobacterial burden in the lung and spleen. Furthermore, in macrophages, lincRNA-MIR99AHG is translocated to the nucleus and interacts with high affinity to hnRNPA2/B1 following IL-4/IL-13 stimulation and Mtb HN878 infection. Together, these findings identify lincRNA-MIR99AHG as a positive regulator of inflammation and macrophage polarization to promote Mtb growth and a possible target for adjunctive host-directed therapy against TB.

LncmiRHG-MIR100HG: A new budding star in cancer

MIR100HG, also known as lncRNA mir-100-let-7a-2-mir-125b-1 cluster host gene, is a new and critical regulator in cancers in recent years. MIR100HG is dysregulated in various cancers and plays an oncogenic or tumor-suppressive role, which participates in many tumor cell biology processes and cancer-related pathways. The errant expression of MIR100HG has inspired people to investigate the function of MIR100HG and its diagnostic and therapeutic potential in cancers. Many studies have indicated that dysregulated expression of MIR100HG is markedly correlated with poor prognosis and clinicopathological features. In this review, we will highlight the characteristics and introduce the role of MIR100HG in different cancers, and summarize the molecular mechanism, pathways, chemoresistance, and current research progress of MIR100HG in cancers. Furthermore, some open questions in this rapidly advancing field are proposed. These updates clarify our understanding of MIR100HG in cancers, which may pave the way for the application of MIR100HG-targeting approaches in future cancer diagnosis, prognosis, and therapy.

MIR99AHG inhibits EMT in pulmonary fibrosis via the miR-136-5p/USP4/ACE2 axis

Background

Long non-coding RNAs (lncRNAs) are closely related to the occurrence and development of cancer. Abnormally expressed lncRNA can be used as a diagnostic marker for cancer. In this study, we aim to investigate the clinical significance of MIR99AHG expression in lung adenocarcinoma (LUAD), and its biological roles in LUAD progression.

Methods

The relative expression of MIR99AHG in LUAD tissues and cell lines was analyzed using public databases and RT-qPCR. The biological functions of MIR99AHG were investigated using a loss-of-function approach. The effect of MIR99AHG on lung fibrosis was assessed by scratch assay, invasion assay and lung fibrosis rat model. FISH, luciferase reporter assay and immunofluorescence were performed to elucidate the underlying molecular mechanisms.

Results

LncRNA MIR99AHG expression level was downregulated in LUAD tissues and cell lines. Low MIR99AHG levels were associated with poorer patient overall survival. Functional analysis showed that MIR99AHG is associated with the LUAD malignant phenotype in vitro and in vivo. Further mechanistic studies showed that, MIR99AHG functions as a competitive endogenous RNA (ceRNA) to antagonize miR-136-5p-mediated ubiquitin specific protease 4 (USP4) degradation, thereby unregulated the expression of angiotensin-converting enzyme 2 (ACE2), a downstream target gene of USP4, which in turn affected alveolar type II epithelial cell fibrosis and epithelial–mesenchymal transition (EMT). In summary, the MIR99AHG/miR-136-5p/USP4/ACE2 signalling axis regulates lung fibrosis and EMT, thus inhibiting LUAD progression.

Conclusion

This study showed that downregulated MIR99AHG leads to the development of pulmonary fibrosis. Therefore, overexpression of MIR99AHG may provide a new approach to preventing LUAD progression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03633-y.

Identification of Prognostic Factors in Cholangiocarcinoma Based on Integrated ceRNA Network Analysis

This study is aimed at screening prognostic biomarkers in cholangiocarcinoma (CHOL) based on competitive endogenous RNA (ceRNA) regulatory network analysis. Microarray data for lncRNAs, mRNA, and miRNAs were downloaded from the GEO and TCGA databases. Differentially expressed RNAs (DERs) were identified in CHOL and normal liver tissue samples. WGCNA was used to identify disease-related gene modules. By integrating the information from the starBase and DIANA-LncBasev2 databases, we constructed a ceRNA network. Survival analysis was performed, and a prognostic gene-based prognostic score (PS) model was generated. The correlation between gene expression and immune cell infiltration or immune-related feature genes was analyzed using TIMER. Finally, real-time quantitative PCR (RT-qPCR) was used to verify the expression of the 10 DERs with independent prognosis. A large cohort of DERs was identified in the CHOL and control samples. The ceRNA network consisted of 6 lncRNAs, 2 miRNAs, 90 mRNAs, and 98 nodes. Ten genes were identified as prognosis-related genes, and a ten-gene signature PS model was constructed, which exhibited a good prognosis predictive ability for risk assessment of CHOL patients (AUC value = 0.975). Four genes, ELF4, AGXT, ABCG2, and LDHD, were associated with immune cell infiltration and closely correlated with immune-related feature genes (CD14, CD163, CD33, etc.) in CHOL. Additionally, the consistency rate of the RT-qPCR results and bioinformatics analysis was 80%, implying a relatively high reliability of the bioinformatic analysis results. Our findings suggest that the ten-signature gene PS model has significant prognostic predictive value for patients with CHOL. These four immune-related DERs are involved in the progression of CHOL and may be useful prognostic biomarkers for CHOLs.

Integrated risk scores from N6-methyladenosine-related lncRNAs are potential biomarkers for predicting the overall survival of bladder cancer patients

Background: N6-methyladenosine (m6A) is the most common form of mRNA- and long noncoding RNA (lncRNA)-specific internal modification encountered in eukaryotes, with important effects on mRNA stability, translation, and splicing. The role of m6A-modified lncRNAs (m6A-lncRNAs) in bladder cancer (BLCA) is rarely reported. This study aimed to evaluate an efficient prognostic model of BLCA in patients, based on m6A-lncRNAs, and to discover potential biological targets.

Methods: Differentially expressed lncRNAs were investigated in 433 BLCA samples derived from The Cancer Genome Atlas (TCGA) database. Kaplan–Meier and univariate Cox regression analyses were performed to screen for m6A-lncRNAs with prognostic roles in BLCA. We implemented Pearson correlation analysis to analyze 18 potentially prognostic lncRNAs and 20 known m6A-associated genes. Next, the data were imputed using least absolute shrinkage and selection operator (LASSO) Cox regression to establish an m6A-lncRNA prognostic signature.

Results: We established an integrated risk score (RS) containing five m6A-lncRNAs and constructed a nomogram that had the ability to forecast the overall survival (OS) of patients with BLCA. We showed that the predictive accuracy of the RS for BLCA prognosis was high, which was confirmed by the area under the receiver operating characteristic (ROC) curve. We analyzed the correlation between tumor immune infiltrating cells and RS in high- and low-risk patients with BLCA and used tumor immune dysfunction and exclusion to predict the effect of immunotherapy. We screened out the most relevant modules of RS through the weighted gene co-expression network analysis network and explored their potential biological functions using GO and KEGG analyses.

Conclusion: Our findings demonstrate that, compared with nomograms constructed using a single prognostic factor, the integrated RS represents a superior model for predicting survival in patients with BLCA, which may improve the clinical management of BLCA.

MIR99AHG/miR-204-5p/TXNIP/Nrf2/ARE Signaling Pathway Decreases Glioblastoma Temozolomide Sensitivity

Glioblastoma (GBM) is the most prevalent primary cerebral tumor in adults with high aggressiveness. Temozolomide (TMZ) is considered as the most widely used chemotherapy for GBM patients. Accumulating studies have proved that long non-coding RNAs (lncRNAs) participate in the pathogenesis of tumors. The aim of our study is to disclose the role of mir-99a-let-7c cluster host gene (MIR99AHG) in GBM. MIR99AHG expression was discovered to be elevated in GBM cells through quantitative real-time polymerase chain reaction (RT-qPCR) analysis. Loss-of-function experiments demonstrated that MIR99AHG silencing enhanced TMZ sensitivity of GBM both in vitro and in vivo. RNA pull down, RNA-binding protein immunoprecipitation (RIP), and luciferase reporter assays were implemented to unveil the underlying mechanism of MIR99AHG in GBM. The results of the mechanism assays implied that MIR99AHG interacted with microRNA-204-5p (miR-204-5p) and enhanced thioredoxin interacting protein (TXNIP) expression to inactivate the Nrf2/ARE signaling pathway. MIR99AHG/miR-204-5p/TXNIP regulatory axis was verified by rescue experiments in GBM. To summarize, MIR99AHG plays a promoting role in the TMZ resistance of GBM cells. The findings in this study might provide novel sight for the treatment for GBM.

Preliminary Study of Genome-Wide Association Identified Novel Susceptibility Genes for Hemorheological Indexes in a Chinese Population

Background

Genome-wide association studies for various hemorheological characteristics have not been reported. We aimed to identify genetic loci associated with hemorheological indexes in a cohort of healthy Chinese Han individuals.

Methods

Genotyping was performed using Applied Biosystems Axiom™ Precision Medicine Diversity Array in 838 individuals, and 6,423,076 single nucleotide polymorphisms were available for genotyping. The relations were examined in an additive genetic model using mixed linear regression and combined with identical by descent matrix.

Results

We identified 38 genetic loci (p < 5 × 10^-6) related to hemorheological traits. In which, LOC102724502-OLIG2 rs28371438 was related to the levels of nd30 (p = 8.58 × 10^-07), nd300 (p = 1.89 × 10^-06), erythrocyte rigidity (p = 1.29 × 10^-06), assigned viscosity (p = 6.20 × 10^-08) and whole blood high cut relative (p = 7.30 × 10^-08). The association of STK32B rs4689231 for nd30 (p = 3.85 × 10^-06) and nd300 (p = 2.94 × 10^-06) and GTSCR1-LINC01541 rs11661911 for erythrocyte rigidity (p = 9.93 × 10^-09) and whole blood high cut relative (p = 2.09 × 10^-07) was found. USP25-MIR99AHG rs1297329 was associated with erythrocyte rigidity (p = 1.81 × 10^-06) and erythrocyte deformation (p = 1.14 × 10^-06). Moreover, the association of TMEM232-SLC25A46 rs3985087 and LINC00470-METTL4 rs9966987 for fibrinogen (p = 1.31 × 10^-06 and p = 4.29 × 10^-07) and plasma viscosity (p = 1.01 × 10^-06 and p = 4.59 × 10^-07) was found.

Conclusion

These findings may represent biological candidates for hemorheological indexes and contribute to hemorheological study.

Hepatic Expression of the Na+-Taurocholate Cotransporting Polypeptide Is Independent from Genetic Variation

The hepatic Na+-taurocholate cotransporting polypeptide NTCP/SLC10A1 is important for the uptake of bile salts and selected drugs. Its inhibition results in increased systemic bile salt concentrations. NTCP is also the entry receptor for the hepatitis B/D virus. We investigated interindividual hepatic SLC10A1/NTCP expression using various omics technologies. SLC10A1/NTCP mRNA expression/protein abundance was quantified in well-characterized 143 human livers by real-time PCR and LC-MS/MS-based targeted proteomics. Genome-wide SNP arrays and SLC10A1 next-generation sequencing were used for genomic analyses. SLC10A1 DNA methylation was assessed through MALDI-TOF MS. Transcriptomics and untargeted metabolomics (UHPLC-Q-TOF-MS) were correlated to identify NTCP-related metabolic pathways. SLC10A1 mRNA and NTCP protein levels varied 44-fold and 10.4-fold, respectively. Non-genetic factors (e.g., smoking, alcohol consumption) influenced significantly NTCP expression. Genetic variants in SLC10A1 or other genes do not explain expression variability which was validated in livers (n = 50) from The Cancer Genome Atlas. The identified two missense SLC10A1 variants did not impair transport function in transfectants. Specific CpG sites in SLC10A1 as well as single metabolic alterations and pathways (e.g., peroxisomal and bile acid synthesis) were significantly associated with expression. Inter-individual variability of NTCP expression is multifactorial with the contribution of clinical factors, DNA methylation, transcriptional regulation as well as hepatic metabolism, but not genetic variation.

LncRNA MIR99AHG enhances adipocyte differentiation by targeting miR-29b-3p to upregulate PPARγ

AIM

The aim is to identify new long noncoding RNAs (lncRNAs) involved in adipocyte differentiation.

METHODS

High-throughput RNA sequencing of 3T3-L1 preadipocytes was carried out before and after differentiation to identify the target lncRNAs and miRNAs. The effects of lncRNA, miRNA and the network mechanism on adipocyte differentiation were evaluated in vitro and in vivo. Visceral adipose tissue (VAT) was collected from Chinese subjects with obesity or a normal body mass index (BMI), and the levels of lncRNAs, adipogenic genes and miRNAs were measured.

RESULTS

MIR99AHG, miR-29b-3p were selected as the target lncRNA and miRNA. Short hairpin RNA against MIR99AHG inhibited the differentiation of 3T3-L1 preadipocytes, reduced the expression of the peroxisome proliferator-activated receptor gamma (PPARγ), CCAAT enhancer-binding protein alpha (C/EBPα) and fatty acid binding protein 4 (FABP4) genes, upregulated the expression of miR-29b-3p. Overexpression of MIR99AHG showed the opposite effects. Overexpression of miR-29b-3p inhibited the differentiation of 3T3-L1 preadipocytes and decreased the PPARγ level, while inhibition of miR-29b-3p showed the opposite effects. MIR99AHG and PPARγ competed for binding to miR-29b-3p. In mice with high-fat diet-induced obesity, MIR99AHG and miR-29b-3p mRNA level were increased and decreased, respectively. Tail vein injection of adeno-associated virus 9-MIR99AHG-RNA interference (AAV9-MIR99AHG-RNAi) reduced the body weight, epididymal fat mass, MIR99AHG level and increased the expression of miR-29b-3p. The expression levels of MIR99AHG, PPARγ, C/EBPα and FABP4 in human visceral adipose tissue were higher in the obese group than in the normal weight group.

CONCLUSIONS

MIR99AHG enhances adipogenesis by regulating miR-29b-3p and PPARγ, providing a new target for therapeutic intervention in obesity.

Aminoflavone upregulates putative tumor suppressor miR-125b-2-3p to inhibit luminal A breast cancer stem cell-like properties

Metastatic breast cancer is incurable and often due to breast cancer stem cell (CSC)-mediated self-renewal. We previously determined that the aryl hydrocarbon receptor (AhR) agonist aminoflavone (AF) inhibits the expression of the CSC biomarker α6-integrin (ITGA6) to disrupt the formation of luminal (hormone receptor-positive) mammospheres (3D breast cancer spheroids). In this study, we performed miRNA-sequencing analysis of luminal A MCF-7 mammospheres treated with AF to gain further insight into the mechanism of AF-mediated anti-cancer and anti-breast CSC activity. AF significantly induced the expression of >70 microRNAs (miRNAs) including miR125b-2-3p, a predicted stemness gene regulator. AF-mediated miR125b-2-3p induction was validated in MCF-7 mammospheres and cells. miR125b-2-3p levels were low in breast cancer tissues irrespective of subtype compared to normal breast tissues. While miR125b-2-3p levels were low in MCF-7 cells, they were much lower in AHR100 cells (MCF-7 cells made unresponsive to AhR agonists). The miR125b-2-3p mimic decreased, while the antagomiR125b-2-3p increased the expression of stemness genes ITGA6 and SOX2 in MCF-7 cells. In MCF-7 mammospheres, the miR125b-2-3p mimic decreased only ITGA6 expression although the antagomiR125b-2-3p increased ITGA6, SOX2 and MYC expression. AntagomiR125b-2-3p reversed AF-mediated suppression of ITGA6. The miR125b-2-3p mimic decreased proliferation, migration, and mammosphere formation while the antagomiR125b-2-3p increased proliferation and mammosphere formation in MCF-7 cells. The miR125b-2-3p mimic also inhibited proliferation, mammosphere formation, and migration in AHR100 cells. AF induced AhR- and miR125b2-3p-dependent anti-proliferation, anti-migration, and mammosphere disruption in MCF-7 cells. Our findings suggest that miR125b-2-3p is a tumor suppressor and AF upregulates miR125b-2-3p to disrupt mammospheres via mechanisms that rely at least partially on AhR in luminal A breast cancer cells.

Long noncoding RNAs as regulators of pediatric acute myeloid leukemia

Long noncoding RNAs (lncRNAs) are increasingly emerging as regulators across human development and disease, and many have been described in the context of hematopoiesis and leukemogenesis. These studies have yielded new molecular insights into the contribution of lncRNAs to AML development and revealed connections between lncRNA expression and clinical parameters in AML patients. In this mini review, we illustrate the versatile functions of lncRNAs in AML, with a focus on pediatric AML, and present examples that may serve as future therapeutic targets or predictive factors.

An Unanticipated Modulation of Cyclin-Dependent Kinase Inhibitors: The Role of Long Non-Coding RNAs

It is now definitively established that a large part of the human genome is transcribed. However, only a scarce percentage of the transcriptome (about 1.2%) consists of RNAs that are translated into proteins, while the large majority of transcripts include a variety of RNA families with different dimensions and functions. Within this heterogeneous RNA world, a significant fraction consists of sequences with a length of more than 200 bases that form the so-called long non-coding RNA family. The functions of long non-coding RNAs range from the regulation of gene transcription to the changes in DNA topology and nucleosome modification and structural organization, to paraspeckle formation and cellular organelles maturation. This review is focused on the role of long non-coding RNAs as regulators of cyclin-dependent kinase inhibitors’ (CDKIs) levels and activities. Cyclin-dependent kinases are enzymes necessary for the tuned progression of the cell division cycle. The control of their activity takes place at various levels. Among these, interaction with CDKIs is a vital mechanism. Through CDKI modulation, long non-coding RNAs implement control over cellular physiology and are associated with numerous pathologies. However, although there are robust data in the literature, the role of long non-coding RNAs in the modulation of CDKIs appears to still be underestimated, as well as their importance in cell proliferation control.

Skin cutaneous melanoma properties of immune-related lncRNAs identifying potential prognostic biomarkers

Skin cutaneous melanoma (SKCM) is one of the most aggressive and life-threatening cancers with high incidence rate, metastasis rate and mortality. Early detection and stratification of risk assessment are essential to treat SKCM and to improve survival rate. The aim of this study is to construct an immune-related lncRNAs (immlncRNAs) prognosis risk model to identify immune biomarkers for early diagnosis, prognosis assessment and target immunotherapy of SKCM. For this purpose, we identified 46 immlncRNAs significantly correlated with SKCM prognosis to construct the prognostic risk model and patients were stratified into the high- and low-risk subgroups according to the developed model. The predictive efficiency of this model has been proved by K-M survival analysis and receiver operating characteristic curve. Moreover, CIBERSORT algorithms confirmed that there were differences in immune cell infiltration between the high- and low-risk groups. Functional enrichment analysis further indicated that immlncRNAs were related to a variety of immune response process signaling pathways, suggesting that relevant immlncRNAs could play an important role in the immune regulation of SKCM. Finally, subgroup analysis and multiple Cox regression analysis further proved the stability of the model. In summary, we successfully constructed a 46 immlncRNA-related prognostic risk score model with excellent predictive efficacy and provided more possibilities to investigate the immune regulation mechanisms and to develop immunotherapy of SKCM.

Non-coding RNAs: are they the protagonist or antagonist in the regulation of leukemia?

The idea of functional non-coding RNAs is taking precedence over the previous notion which believed that they only comprise the auxiliary and junk material of the genome. Newer technologies and studies have proven their importance in regulating and affecting several cellular processes. One such area of research wherein their importance has started to take light is in cancer research, particularly leukemia. Myeloid leukemia is a blood malignancy birthed from mutations in hematopoiesis that disable myeloid progenitor cells from proper differentiation. This review will compile the most recent findings regarding the effects of these regulatory non-coding RNAs on the two types of myeloid leukemia. In particular, the effects of circular RNAs, micro RNAs and long non-coding RNAs, on the pathogenesis and proliferation of Acute and Chronic myeloid leukemia will be revealed in a molecular, cellular and prognostic light. The mechanisms of proliferation, gene-to-gene interactions and possible therapeutic effects will also be discussed. Finally, an understanding of the overall "goodness" and "badness" of these non-coding RNAs will be summarised. This review hopes to provide a platform for easy access to data regarding the current non-coding RNAs in myeloid leukemia, for faster and easier research. Finally, the review will summarize a few key players that have protagonistic and antagonistic functions, and those that regulate multiple pathways in leukemia simultaneously.

Testing lncRNAs signature as clinical stage–related prognostic markers in gastric cancer progression using TCGA database

LncRNA expression can be conducive to gastric cancer (GC) prognosis. The objective of this study is to ascertain five specific lncRNAs involved in tumor progression of GC and their role as prognostic markers to diagnose clinical stage-wise GC. High-throughput RNA sequencing data were obtained from The Cancer Genome Atlas (TCGA) database and performed genome-wide lncRNA expression analysis using edgeR package, Bioconductor.org , and R-statistical computing to analyze differentially expressed lncRNA analysis. Cutoff parameters were FDR < 0.05 and |Log2FC| > 2. Total 351 tumor samples with differentially expressed lncRNAs were divided into group-1 lncRNAs such as AC019117.2 and LINC00941, and group-2 lncRNAs such as LINC02410, AC012317.2, and AC141273.1 by 2:1. The Spearman correlation coefficients ( p < 0.05) and correlation test function (cor.test ()) were performed for lncRNAs as per clinical stage. Cytoscape software was used to construct lncRNA–mRNA interaction networks. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway ( p < 0.05) analysis were conducted using the clusterProfiler package. Kaplan–Meier survival analysis was performed to determine the overall survival of patients based on the expression of five lncRNAs in different clinical stages of GC. AC019117.2 and LINC00941 of group 1 inferred a positive correlation with clinical stages of stage I to stage IV, and their expressions were higher in tumor tissues than normal tissues. On the contrary, LINC02410, AC012317.2, and AC141273.1 of group 2 exhibited a negative correlation with clinical stage, and they exhibited more expression in normal tissues compared to tumor tissues. GO and KEGG pathway analysis reported that AC019117.2 may interact with LINC00941 via ITGA3 and trophoblast glycoprotein (TPBG) to foster tumor progression. Tumor-specific group-1 lncRNAs were conducive to the poor overall survival and exhibited a positive correlation with the clinical stages of stage I to stage IV in GC as per the lncRNA–mRNA networking analysis. These five lncRNAs could be considered as clinically useful lncRNA-based prognostic markers to predict clinical stage-wise GC progression.

Fusion gene detection by RNA-sequencing complements diagnostics of acute myeloid leukemia and identifies recurring NRIP1-MIR99AHG rearrangements

Identification of fusion genes in clinical routine is mostly based on cytogenetics and targeted molecular genetics, such as metaphase karyotyping, fluorescence in situ hybridization and reverse-transcriptase polymerase chain reaction. However, sequencing technologies are becoming more important in clinical routine as processing time and costs per sample decrease. To evaluate the performance of fusion gene detection by RNAsequencing compared to standard diagnostic techniques, we analyzed 806 RNA-sequencing samples from patients with acute myeloid leukemia using two state-of-the-art software tools, namely Arriba and FusionCatcher. RNA-sequencing detected 90% of fusion events that were reported by routine with high evidence, while samples in which RNA-sequencing failed to detect fusion genes had overall lower and inhomogeneous sequence coverage. Based on properties of known and unknown fusion events, we developed a workflow with integrated filtering strategies for the identification of robust fusion gene candidates by RNA-sequencing. Thereby, we detected known recurrent fusion events in 26 cases that were not reported by routine and found discrepancies in evidence for known fusion events between routine and RNA-sequencing in three cases. Moreover, we identified 157 fusion genes as novel robust candidates and comparison to entries from ChimerDB or Mitelman Database showed novel recurrence of fusion genes in 14 cases. Finally, we detected the novel recurrent fusion gene NRIP1- MIR99AHG resulting from inv(21)(q11.2;q21.1) in nine patients (1.1%) and LTN1-MX1 resulting from inv(21)(q21.3;q22.3) in two patients (0.25%). We demonstrated that NRIP1-MIR99AHG results in overexpression of the 3' region of MIR99AHG and the disruption of the tricistronic miRNA cluster miR-99a/let-7c/miR-125b-2. Interestingly, upregulation of MIR99AHG and deregulation of the miRNA cluster, residing in the MIR99AHG locus, are known mechanisms of leukemogenesis in acute megakaryoblastic leukemia. Our findings demonstrate that RNA-sequencing has a strong potential to improve the systematic detection of fusion genes in clinical applications and provides a valuable tool for fusion discovery.

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

Background

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

Methods

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

Results

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

Conclusions

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

Overexpression of lncRNAs with endogenous lengths and functions using a lncRNA delivery system based on transposon

Background

Long noncoding RNAs (lncRNAs) play important roles in many physiological and pathological processes, this indicates that lncRNAs can serve as potential targets for gene therapy. Stable expression is a fundamental technology in the study of lncRNAs. The lentivirus is one of the most widely used delivery systems for stable expression. However, it was initially designed for mRNAs, and the applicability of lentiviral vectors for lncRNAs is largely unknown.

Results

We found that the lentiviral vector produces lncRNAs with improper termination, appending an extra fragment of ~ 2 kb to the 3ʹ-end. Consequently, the secondary structures were changed, the RNA–protein interactions were blocked, and the functions were impaired in certain lncRNAs, which indicated that lentiviral vectors are not ideal delivery systems of lncRNAs. Here, we developed a novel lncRNA delivery method called the Expression of LncRNAs with Endogenous Characteristics using the Transposon System (ELECTS). By inserting a termination signal after the lncRNA sequence, ELECTS produces transcripts without 3ʹ-flanking sequences and retains the native features and function of lncRNAs, which cannot be achieved by lentiviral vectors. Moreover, ELECTS presents no potential risk of infection for the operators and it takes much less time. ELECTS provides a reliable, convenient, safe, and efficient delivery method for stable expression of lncRNAs.

Conclusions

Our study demonstrated that improper transcriptional termination from lentiviral vectors have fundamental effects on molecular action and cellular function of lncRNAs. The ELECTS system developed in this study will provide a convenient and reliable method for the lncRNA study.

Graphic Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-021-01044-7.

Long noncoding RNAs: A novel insight in the leukemogenesis and drug resistance in acute myeloid leukemia

Acute myeloid leukemia (AML) is a common hematological disorder with heterogeneous nature that resulted from blocked myeloid differentiation and an enhanced number of immature myeloid progenitors. During several decades, different factors, including cytogenetic, genetic, and epigenetic have been reported to contribute to the pathogenesis of AML by inhibiting the differentiation and ensuring the proliferation of myeloid blast cells. Recently, long noncoding RNAs (lncRNAs) have been considered as potential diagnostic, therapeutic, and prognostic factors in different human malignancies including AML. Altered expression of lncRNAs is correlated with the transformation of hematopoietic stem and progenitor cells into leukemic blast cells because of their distinct role in the key cellular processes. We discuss the significant role of lncRNAs in the proliferation, survival, differentiation, leukemic stem cells in AML and their involvement in different molecular pathways (insulin-like growth factor type I receptor, FLT3, c-KIT, Wnt, phosphatidylinositol 3-kinase/protein kinase-B, microRNAs), and associated mechanisms such as autophagy, apoptosis, and glucose metabolism. In addition, we aim to highlight the role of lncRNAs as reliable biomarkers for diagnosis, prognosis, and drug resistance for precision medicine in AML.

Drug resistance in colorectal cancer: An epigenetic overview

Colorectal cancer (CRC) is a leading cause of cancer-related deaths worldwide. Despite significant progress that has been made in therapies against CRC over the past decades, drug resistance is still a major limitation in CRC treatment. Numerous investigations have unequivocally shown that epigenetic regulation plays an important role in CRC drug resistance because of the high rate of epigenetic alterations in multiple genes during cancer development or drug treatment. Furthermore, the reversibility of epigenetic alterations provides novel therapeutic strategies to overcome drug resistance using small molecules, which can target non-coding RNAs or reverse histone modification and DNA methylation. In this review, we discuss epigenetic regulation in CRC drug resistance and the possible role of preventing or reversing CRC drug resistance using epigenetic therapy in CRC treatment.

LncRNA as a multifunctional regulator in cancer multi-drug resistance

BACKGROUND

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

METHODS AND RESULTS

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

CONCLUSIONS

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

Long Noncoding RNA MIR100HG Knockdown Attenuates Hepatocellular Carcinoma Progression by Regulating MicroRNA-146b-5p/Chromobox 6

PURPOSE

Hepatocellular carcinoma (HCC) accounts for approximately ninety percent of primary liver cancer. This study attempted to investigate the effects of the long noncoding RNA MIR100HG (MIR100HG) in HCC and the underlying molecular mechanism.

MATERIALS AND METHODS

qRT-PCR was implemented to analyze the expression of MIR100HG, microRNA-146b-5p (miR-146b-5p), and Chromobox 6 (CBX6). The correlation between MIR100HG and clinicopathological features of HCC patients was assessed. Additionally, the effects of MIR100HG knockdown on HCC cell viability, migration, and invasion were explored. The interactions among MIR100HG, miR-146b-5p, and CBX6 were confirmed. Furthermore, rescue experiments were conducted to investigate whether MIR100HG knockdown modulates HCC cell behaviors through modulating the miR-146b-5p/CBX6 axis.

RESULTS

The expression of MIR100HG and CBX6 was enhanced, while miR-146b-5p was inhibited in HCC cells. High MIR100HG expression was positively associated with the TNM tumor stage and Edmondson-Steiner grading in HCC patients. MIR100HG knockdown considerably reduced the HCC cell viability, migration, and invasion. In addition, MIR100HG directly targeted miR-146b-5p, and miR-146b-5p directly targeted CBX6 in HCC cells. Moreover, miR-146b-5p suppression or CBX6 elevation evidently rescued the suppressed viability, migration, and invasion of HCC cells caused by MIR100HG knockdown.

CONCLUSIONS

Knockdown of MIR100HG inhibited the viability, migration, and invasion of HCC cells by targeting the miR-146b-5p/CBX6 axis, offering a potential therapeutic target for HCC therapy.

An immunotherapeutic approach to decipher the role of long non-coding RNAs in cancer progression, resistance and epigenetic regulation of immune cells

Immunotherapeutic treatments are gaining attention due to their effective anti-tumor response. Particularly, the revolution of immune checkpoint inhibitors (ICIs) produces promising outcomes for various cancer types. However, the usage of immunotherapy is limited due to its low response rate, suggesting that tumor cells escape the immune surveillance. Rapid advances in transcriptomic profiling have led to recognize immune-related long non-coding RNAs (LncRNAs), as regulators of immune cell-specific gene expression that mediates immune stimulatory as well as suppression of immune response, indicating LncRNAs as targets to improve the efficacy of immunotherapy against tumours. Moreover, the immune-related LncRNAs acting as epigenetic modifiers are also under deep investigation. Thus, herein, is a summarised knowledge of LncRNAs and their regulation in the adaptive and innate immune system, considering their importance in autophagy and predicting putative immunotherapeutic responses.

Role of mammalian long non-coding RNAs in normal and neuro oncological disorders

Long non-coding RNAs (lncRNAs) are expressed at lower levels than protein-coding genes but have a crucial role in gene regulation. LncRNA is distinct, they are being transcribed using RNA polymerase II, and their functionality depends on subcellular localization. Depending on their niche, they specifically interact with DNA, RNA, and proteins and modify chromatin function, regulate transcription at various stages, forms nuclear condensation bodies and nucleolar organization. lncRNAs may also change the stability and translation of cytoplasmic mRNAs and hamper signaling pathways. Thus, lncRNAs affect the physio-pathological states and lead to the development of various disorders, immune responses, and cancer. To date, ~40% of lncRNAs have been reported in the nervous system (NS) and are involved in the early development/differentiation of the NS to synaptogenesis. LncRNA expression patterns in the most common adult and pediatric tumor suggest them as potential biomarkers and provide a rationale for targeting them pharmaceutically. Here, we discuss the mechanisms of lncRNA synthesis, localization, and functions in transcriptional, post-transcriptional, and other forms of gene regulation, methods of lncRNA identification, and their potential therapeutic applications in neuro oncological disorders as explained by molecular mechanisms in other malignant disorders.

Identification and Roles of miR-29b-1-3p and miR29a-3p-Regulated and Non-Regulated lncRNAs in Endocrine-Sensitive and Resistant Breast Cancer Cells

Despite improvements in the treatment of endocrine-resistant metastatic disease using combination therapies in patients with estrogen receptor α (ERα) primary tumors, the mechanisms underlying endocrine resistance remain to be elucidated. Non-coding RNAs (ncRNAs), including microRNAs (miRNA) and long non-coding RNAs (lncRNA), are targets and regulators of cell signaling pathways and their exosomal transport may contribute to metastasis. Previous studies have shown that a low expression of miR-29a-3p and miR-29b-3p is associated with lower overall breast cancer survival before 150 mos. Transient, modest overexpression of miR-29b1-3p or miR-29a-3p inhibited MCF-7 tamoxifen-sensitive and LCC9 tamoxifen-resistant cell proliferation. Here, we identify miR-29b-1/a-regulated and non-regulated differentially expressed lncRNAs in MCF-7 and LCC9 cells using next-generation RNA seq. More lncRNAs were miR-29b-1/a-regulated in LCC9 cells than in MCF-7 cells, including DANCR, GAS5, DSCAM-AS1, SNHG5, and CRND. We examined the roles of miR-29-regulated and differentially expressed lncRNAs in endocrine-resistant breast cancer, including putative and proven targets and expression patterns in survival analysis using the KM Plotter and TCGA databases. This study provides new insights into lncRNAs in endocrine-resistant breast cancer.

LncRNA MONC suppresses the malignant phenotype of Endometrial Cancer Stem Cells and Endometrial Carcinoma Cells by regulating the MiR-636/GLCE axis

Background

Emerging evidence shows that abnormal expression of long non-coding RNA is involved in the occurrence and development of various tumors. LncRNA MONC is abnormally expressed in head and neck squamous cell carcinoma, lung cancer, colorectal cancer, and acute megakaryocytic leukemia, but the biological function and potential regulatory mechanism of MONC in endometrial cancer stem cells (ECSCs) and endometrial cancer cells (ECCs) have not been studied. In this study, we aimed to explore the tumor suppressive effect and mechanism of MONC in regulating ECSCs and ECCs.

Methods

We used qRT-PCR to detect the expression of MONC, miR-636 and GLCE in normal human endometrial tissues and endometrial carcinoma (EC) tissues. Luciferase assay was used to verify the binding sites between MONC and miR-636 and between miR-636 and GLCE. Double fluorescence in situ hybridization was used to locate MONC and miR-636 in cells. ECSCs were obtained by flow cytometry sorting assay. Sphere formation assay, CCK-8 assay, transwell invasion assay, cell cycle analysis and apoptosis assay were used to detect the effects of MONC/miR-636/GLCE axis on the malignant biological behavior of ECSCs and ECCs. The effect of MONC on the epithelial-to-mesenchymal transition (EMT) process was detected using western blot. Finally, we conducted in vivo verification through Tumor xenografts in BALB/C nude mice.

Results

In this study, we found MONC is low expression in endometrial carcinoma (EC) and patients in the MONC high-expression group had a better prognosis. MONC and miR-636 are relatively co-localized in the cytoplasm. MONC directly inhibits the malignant biological behavior of ECSCs and ECCs by directly inhibiting miR-636. Simultaneously, miR-636 may indirectly reduce the expression of MONC. Down-regulation of miR-636 may promote GLCE expression by targeting the 3′-untranslated region (UTR) of the downstream gene GLCE, thereby inhibiting the progression of ECSCs. MONC combined with miR-636 inhibited tumor epithelial-to-mesenchymal transition (EMT) process. In addition, we verified the tumor suppressive effect of MONC in nude mice, miR-636 can rescue the tumor suppressive effect of overexpressing MONC.

Conclusions

In conclusion, this study showed that MONC inhibits the malignant phenotypes of ECSCs and ECCs by regulating the miR-636/GLCE axis. Thus the MONC/miR-636/GLCE axis may provide novel treatment avenues for human EC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-01911-1.

The Landscape of Coding and Noncoding RNAs in Platelets

Significance: Levels of platelet noncoding RNAs (ncRNAs) are altered by disease, and ncRNAs may exert functions inside and outside of platelets. Their role in physiologic hemostasis and pathologic thrombosis remains to be explored. Recent Advances: The number of RNA classes identified in platelets has been growing since the past decade. Apart from coding messenger RNAs, the RNA landscape in platelets comprises ncRNAs such as microRNAs, circular RNAs, long ncRNAs, YRNAs, and potentially environmentally derived exogenous ncRNAs. Recent research has focused on the function of platelet RNAs beyond platelets, mediated through protective RNA shuttles or even cellular uptake of entire platelets. Multiple studies have also explored the potential of platelet RNAs as novel biomarkers. Critical Issues: Platelet preparations can contain contaminating leukocytes. Even few leukocytes may contribute a substantial amount of RNA. As biomarkers, platelet RNAs have shown associations with platelet activation, but it remains to be seen whether their measurements could improve diagnostics. It also needs to be clarified whether platelet RNAs influence processes beyond platelets. Future Directions: Technological advances such as single-cell RNA-sequencing might help to identify hyperreactive platelet subpopulations on a single-platelet level, avoid the common problem of leukocyte contamination in platelet preparations, and allow simultaneous profiling of native megakaryocytes and their platelet progeny to clarify to what extent the platelet RNA content reflects their megakaryocyte precursors or changes in the circulation. Antioxid. Redox Signal. 34, 1200-1216.

Cis-acting: A pattern of lncRNAs for gene regulation in induced pluripotent stem cells from patients with Down syndrome determined by integrative analysis of lncRNA and mRNA profiling data

Down syndrome (DS), caused by the trisomy of chromosome 21, is one of the common chromosomal disorders, the main clinical manifestations of which are delayed nervous development and intellectual disability. Long non-coding RNAs (lncRNAs) have critical roles in various biological processes, including cell growth, cell cycle regulation and differentiation. The roles of abnormally expressed lncRNAs have been previously reported; however, the biological functions and regulatory patterns of lncRNAs in DS have remained largely elusive. The aim of the present study was to perform a whole-genome-wide identification of lncRNAs and mRNAs associated with DS. In addition, global expression profiling analysis of DS-induced pluripotent stem cells was performed and differentially expressed (DE) lncRNAs and mRNAs were screened. Furthermore, the target genes and functions of the DE lncRNAs were predicted using Gene Ontology annotation and Kyoto Encyclopedia of Genes and Genomes signaling pathway enrichment analysis. The results revealed that the majority of the lncRNAs exerted functions in DS via cis-acting target genes. In addition, the results of the enrichment analysis indicated that these target genes were mainly involved in nervous and muscle development in DS. In conclusion, this integrative analysis using lncRNA and mRNA profiling provided novel insight into the pathogenesis of DS and it may promote the diagnosis and development of novel therapeutics for this disease.