lncRNAs in development and disease: from functions to mechanisms

Autophagy-related lncRNAs and exosomal lncRNAs in colorectal cancer: focusing on lncRNA-targeted strategies

Autophagy is a cellular process that involves the degradation and recycling of cellular components, including damaged proteins and organelles. It is an important mechanism for maintaining cellular homeostasis and has been implicated in various diseases, including cancer. Long non-coding RNAs (lncRNAs) are a class of RNA molecules that do not code for proteins but instead play regulatory roles in gene expression. Emerging evidence suggests that lncRNAs can influence autophagy and contribute to the development and progression of colorectal cancer (CRC). Several lncRNAs have been identified as key players in modulating autophagy in CRC. The dysregulation of autophagy and non-coding RNAs (ncRNAs) in CRC suggests a complex interplay between these two factors in the pathogenesis of the disease. Modulating autophagy may sensitize cancer cells to existing therapies or improve the efficacy of new treatment approaches. Additionally, targeting specific lncRNAs involved in autophagy regulation could potentially be used as a therapeutic intervention to inhibit tumor growth, metastasis, and overcome drug resistance in CRC. In this review, a thorough overview is presented, encompassing the functions and underlying mechanisms of autophagy-related lncRNAs in a range of critical areas within tumor biology. These include cell proliferation, apoptosis, migration, invasion, drug resistance, angiogenesis, and radiation resistance.

In silico identification and functional study of long non-coding RNA involved in acute hepatopancreatic necrosis disease caused by Vibrio parahaemolyticus infection in white shrimp, Litopenaeus vannamei

Acute hepatopancreatic necrosis disease (AHPND) caused by toxin-producing Vibrio parahaemolyticus (VpAHPND) has severely affected shrimp production. Long non-coding RNA (lncRNA), a regulatory non-coding RNA, which can play important function in shrimp disease responses. This study aimed to identify and investigate the role of lncRNA involved in VpAHPND infection in Pacific white shrimp, Litopenaeus vannamei. From a total of 368,736 de novo assembled transcripts, 67,559 were identified as putative lncRNAs, and only 72 putative lncRNAs showed differential expression between VpAHPND-infected and normal shrimp. The six candidate lncRNAs were validated for their expression profiles during VpAHPND infection and tissue distribution using RT-qPCR. The role of lnc2088 in response to VpAHPND infection was investigated through RNA interference. The result indicated that the suppression of lnc2088 expression led to an increase in shrimp mortality after VpAHPND infection. To explore the set of genes involved in lnc2088 knockdown, RNA sequencing was performed. A total of 275 differentially expressed transcripts were identified in the hepatopancreas of lnc2088 knockdown shrimp. The expression profiles of five candidate metabolic and immune-related genes were validated in lnc2088 knockdown and VpAHPND-infected shrimp. The result showed that the expression of ChiNAG was significantly increased, while that of NCBP1, WIPF2, and NFKB1 was significantly downregulated in ds2088-injected shrimp. Additionally, the expression of NFKB1, NCBP1 and WIPF2 was significantly increased, whereas that of ChiNAG and CUL5 were significantly decreased after infection with VpAHPND. Our work identified putative lncRNA profiles in L. vannamei in response to VpAHPND infection and investigated the role of lncRNA in shrimp immunity.

LncRNAs and asymmetric cell division: the epigenetic mechanisms

Asymmetric cell division (ACD) plays a pivotal role in development, tissue homeostasis, and stem cell maintenance. Emerging evidence suggests that long non-coding RNAs (lncRNAs) are key regulators of ACD, orchestrating the intricate molecular machinery that governs cell fate determination. This review summarizes current literature to elucidate the diverse roles of lncRNAs in modulating ACD across various biological contexts. The regulatory mechanisms of asymmetric cell division mediated by lncRNAs, including their interactions with protein effectors, epigenetic regulation, and subcellular localization are explored. Additionally, we discuss the implications of dysregulated lncRNAs in mediating ACD that lead to tumorigenesis. By integrating findings from diverse experimental models and cell types, this review provides insights into the multifaceted roles of lncRNAs in governing asymmetric cell division, shedding light on fundamental biological processes. Further research in this area may lead to the development of novel therapies targeting dysregulated lncRNAs to restore proper cell division and function. The knowledge of lncRNAs regulating ACD could potentially revolutionize the field of regenerative medicine and cancer therapy by targeting specific lncRNAs involved in ACD. By unraveling the complex interactions between lncRNAs and cellular processes, the potential novel opportunities for precision medicine approaches may be uncovered.

Identification of SLC7A11-AS1/SLC7A11 pair as a ferroptosis-related therapeutic target for hepatocellular carcinoma

Hepatocellular carcinoma (HCC), a prevalent malignancy worldwide, poses significant challenges in terms of prognosis, necessitating innovative therapeutic approaches. Ferroptosis offers notable advantages over apoptosis, holding promise as a novel therapeutic approach for HCC complexities. Moreover, while the interaction between long non-coding RNAs (lncRNAs) and mRNAs is pivotal in various physiological and pathological processes, their involvement in ferroptosis remains relatively unexplored. In this study, we constructed a ferroptosis-related lncRNA-mRNA correlation network in HCC using Pearson correlation analysis. Notably, the SLC7A11-AS1/SLC7A11 pair, exhibiting high correlation, was identified. Bioinformatics analysis revealed a significant correlation between the expression levels of this pair and key clinical characteristics of HCC patients, including gender, pathology, Ishak scores and tumour size. And poor prognosis was associated with high expression of this pair. Functional experiments demonstrated that SLC7A11-AS1, by binding to the 3'UTR region of SLC7A11 mRNA, enhanced its stability, thereby promoting HCC cell growth and resistance to erastin- induced ferroptosis. Additionally, in vivo studies confirmed that SLC7A11-AS1 knockdown potentiated the inhibitory effects of erastin on tumour growth. Overall, our findings suggest that targeting the SLC7A11-AS1/SLC7A11 pair holds promise as a potential therapeutic strategy for HCC patients.

Novel insights on the positive correlation between sense and antisense pairs on gene expression

A considerable proportion of the eukaryotic genome undergoes transcription, leading to the generation of noncoding RNA molecules that lack protein-coding information and are not subjected to translation. These noncoding RNAs (ncRNAs) are well recognized to have essential roles in several biological processes. Long noncoding RNAs (lncRNAs) represent the most extensive category of ncRNAs found in the human genome. Much research has focused on investigating the roles of cis-acting lncRNAs in the regulation of specific target gene expression. In the majority of instances, the regulation of sense gene expression by its corresponding antisense pair occurs in a negative (discordant) manner, resulting in the suppression of the target genes. The notion that a negative correlation exists between sense and antisense pairings is, however, not universally valid. In fact, several recent studies have reported a positive relationship between corresponding cis antisense pairs within plants, budding yeast, and mammalian cancer cells. The positive (concordant) correlation between anti-sense and sense transcripts leads to an increase in the level of the sense transcript within the same genomic loci. In addition, mechanisms such as altering chromatin structure, the formation of R loops, and the recruitment of transcription factors can either enhance transcription or stabilize sense transcripts through their antisense pairs. The primary objective of this work is to provide a comprehensive understanding of both aspects of antisense regulation, specifically focusing on the positive correlation between sense and antisense transcripts in the context of eukaryotic gene expression, including its implications towards cancer progression. This article is categorized under: RNA Processing > 3' End Processing Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs.

RNA biomarkers in cancer therapeutics: The promise of personalized oncology

Cancer therapy is a rapidly evolving and constantly expanding field. Current approaches include surgery, conventional chemotherapy and novel biologic agents as in immunotherapy, that together compose a wide armamentarium. The plethora of choices can, however, be clinically challenging in prescribing the most suitable treatment for any given patient. Fortunately, biomarkers can greatly facilitate the most appropriate selection. In recent years, RNA-based biomarkers have proven most promising. These molecules that range from small noncoding RNAs to protein coding gene transcripts can be valuable in cancer management and especially in cancer therapeutics. Compared to their DNA counterparts which are stable throughout treatment, RNA-biomarkers are dynamic. This allows prediction of success prior to treatment start and can identify alterations in expression that could reflect response. Moreover, improved nucleic acid technology allows RNA to be extracted from practically every biofluid/matrix and evaluated with exceedingly high analytic sensitivity. In addition, samples are largely obtained by minimally invasive procedures and as such can be used serially to assess treatment response real-time. This chapter provides the reader insight on currently known RNA biomarkers, the latest research employing Artificial Intelligence in the identification of such molecules and in clinical decisions driving forward the era of personalized oncology.

An extensive overview of the role of lncRNAs generated from immune cells in the etiology of cancer

Long non-coding RNAs (lncRNAs) are involved in the control of critical tumor-suppressor and oncogenic pathways in cancer. These types of non-coding RNAs could affect both immune and cancer cells. The thorough analysis of lncRNAs derived from immune cells and the incorporation of new findings significantly advance our understanding of the complex role of lncRNAs in the context of cancer. This work highlights the promise of lncRNAs for translational therapeutic approaches while also establishing a solid foundation for comprehending the complex link between lncRNAs and cancer through a coherent narrative. The main findings of this article are that types of lncRNAs derived from immune cells, such as MM2P and MALAT1, can affect the behaviors of cancer cells, like invasion, angiogenesis, and proliferation. As research in this area grows, the therapeutic potential of targeting these lncRNAs offers promising opportunities for expanding our understanding of cancer biology and developing cutting-edge, precision-based therapies for cancer therapy.

Deciphering the oncogenic landscape: Unveiling the molecular machinery and clinical significance of LncRNA TMPO-AS1 in human cancers

The in-depth exploration of long non-coding RNAs (lncRNAs) reveals their pivotal and diverse roles in various disorders, particularly cancer. Within this intricate landscape, thymopoietin-antisense RNA-1 (TMPO-AS1) emerges as a noteworthy instigator of oncogenesis in humans. This exhaustive review seeks to intricately unravel the present understanding of TMPO-AS1, emphasizing its molecular foundations and highlighting its clinical applications in the realm of cancer research. TMPO-AS1 consistently exhibits heightened expression across a spectrum of cancer types, encompassing lung, colorectal, breast, cervical, bladder, pancreatic, hepatocellular, gastric, ovarian, and osteosarcoma. Elevated levels of TMPO-AS1 are intricately linked to unfavorable prognoses, accompanied by distinctive clinical and pathological characteristics. Functionally, TMPO-AS1 showcases its prowess in enhancing cancer cell migration, invasion, proliferation, and orchestrating epithelial-mesenchymal transition (EMT) through a myriad of molecular mechanisms. These mechanisms entail intricate interactions with proteins, microRNAs, and intricate signaling pathways. Furthermore, TMPO-AS1 is intricately involved in regulating critical cellular processes, including apoptosis and the cell cycle. The mounting evidence converges towards the potential of TMPO-AS1 serving as a diagnostic and prognostic biomarker, further entwined with its potential role in influencing chemoresistance in cancer. This potential is underscored by its consistent associations with clinical outcomes and treatment responses. This comprehensive investigation not only consolidates our existing knowledge of TMPO-AS1's multifaceted roles but also sheds illuminating insights on its profound significance in the intricate landscape of cancer biology, paving the way for potential applications in clinical practice.

Long noncoding RNA ABHD11-AS1 interacts with SART3 and regulates CD44 RNA alternative splicing to promote lung carcinogenesis

Hexavalent chromium [Cr(VI)] is a common environmental pollutant and chronic exposure to Cr(VI) causes lung cancer in humans, however, the mechanism of Cr(VI) carcinogenesis has not been well understood. Lung cancer is the leading cause of cancer-related death, although the mechanisms of how lung cancer develops and progresses have been poorly understood. While long non-coding RNAs (lncRNAs) are found abnormally expressed in cancer, how dysregulated lncRNAs contribute to carcinogenesis remains largely unknown. The goal of this study is to investigate the mechanism of Cr(VI)-induced lung carcinogenesis focusing on the role of the lncRNA ABHD11 antisense RNA 1 (tail to tail) (ABHD11-AS1). It was found that the lncRNA ABHD11-AS1 expression levels are up-regulated in chronic Cr(VI) exposure-transformed human bronchial epithelial cells, chronically Cr(VI)-exposed mouse lung tissues, and human lung cancer cells as well. Bioinformatics analysis revealed that ABHD11-AS1 levels are up-regulated in lung adenocarcinomas (LUADs) tissues and associated with worse overall survival of LUAD patients but not in lung squamous cell carcinomas. It was further determined that up-regulation of ABHD11-AS1 expression plays an important role in chronic Cr(VI) exposure-induced cell malignant transformation and tumorigenesis, and the stemness of human lung cancer cells. Mechanistically, it was found that ABHD11-AS1 directly binds SART3 (spliceosome associated factor 3, U4/U6 recycling protein). The interaction of ABHD11-AS1 with SART3 promotes USP15 (ubiquitin specific peptidase 15) nuclear localization. Nuclear localized USP15 interacts with pre-mRNA processing factor 19 (PRPF19) to increase CD44 RNA alternative splicing activating β-catenin and enhancing cancer stemness. Together, these findings indicate that lncRNA ABHD11-AS1 interacts with SART3 and regulates CD44 RNA alternative splicing to promote cell malignant transformation and lung carcinogenesis.

LncRNADisease v3.0: an updated database of long non-coding RNA-associated diseases

Systematic integration of lncRNA-disease associations is of great importance for further understanding their underlying molecular mechanisms and exploring lncRNA-based biomarkers and therapeutics. The database of long non-coding RNA-associated diseases (LncRNADisease) is designed for the above purpose. Here, an updated version (LncRNADisease v3.0) has curated comprehensive lncRNA (including circRNA) and disease associations from the burgeoning literatures. LncRNADisease v3.0 exhibits an over 2-fold increase in experimentally supported associations, with a total of 25440 entries, compared to the last version. Besides, each lncRNA-disease pair is assigned a confidence score based on experimental evidence. Moreover, all associations between lncRNAs/circRNAs and diseases are classified into general associations and causal associations, representing whether lncRNAs or circRNAs can directly lead to the development or progression of corresponding diseases, with 15721 and 9719 entries, respectively. In a case study, we used the data of LncRNADisease v3.0 to calculate the phenotypic similarity between human and mouse lncRNAs. This database will continue to serve as a valuable resource for potential clinical applications related to lncRNAs and circRNAs. LncRNADisease v3.0 is freely available at http://www.rnanut.net/lncrnadisease.

MALAT1: A key regulator in lung cancer pathogenesis and therapeutic targeting

Lung cancer remains a formidable global health burden, necessitating a comprehensive understanding of the underlying molecular mechanisms driving its progression. Recently, lncRNAs have become necessary controllers of various biological functions, including cancer development. MALAT1 has garnered significant attention due to its multifaceted role in lung cancer progression. Lung cancer, among other malignancies, upregulates MALAT1. Its overexpression has been associated with aggressive tumor behavior and poor patient prognosis. MALAT1 promotes cellular proliferation, epithelial-mesenchymal transition (EMT), and angiogenesis in lung cancer, collectively facilitating tumor growth and metastasis. Additionally, MALAT1 enhances cancer cell invasion by interacting with numerous signaling pathways. Furthermore, MALAT1 has been implicated in mediating drug resistance in lung cancer, contributing to the limited efficacy of conventional therapies. Recent advancements in molecular biology and high-throughput sequencing technologies have offered fresh perspectives into the regulatory networks of MALAT1 in lung cancer. It exerts its oncogenic effects by acting as a ceRNA to sponge microRNAs, thereby relieving their inhibitory effects on target genes. Moreover, MALAT1 also influences chromatin remodeling and post-translational modifications to modulate gene expression, further expanding its regulatory capabilities. This review sheds light on the multifaceted roles of MALAT1 in lung cancer progression, underscoring its potential as an innovative therapeutic target and diagnostic biomarker. Targeting MALAT1 alone or combined with existing therapies holds promise to mitigate lung cancer progression and improve patient outcomes.

Involvement of FAM170B-AS1, hsa-miR-1202, and hsa-miR-146a-5p in breast cancer

BACKGROUND

FAM170B-AS1 is usually expressed low in all organs except for testicular tissues. No study was performed to explore its role in breast cancer (BC). Contradictory results were reported about hsa-miR-1202 and hsa-miR-146a-5p in BC.

OBJECTIVE

The present study aimed to explore the involvement of FAM170B-AS1 in BC using bioinformatics predictive tools, followed by a practical validation besides exploring the impact of hsa-miR-1202 and hsa-miR-146a-5p in BC.

METHODS

This study enrolled 96 female patients with BC, 30 patients with benign breast diseases (BBD), and 25 control subjects. The expressions of circulating FAM170B-AS1, hsa-miR-1202, and hsa-miR-146a-5p were quantified using qRT-PCR. These ncRNAs' associations, predictive, and diagnostic roles in BC were statistically tested. The underlying miRNA/mRNA targets of FAM170B-AS1 in BC were bioinformatically predicted followed by confirmation based on the GEPIA and TCGA databases.

RESULTS

The expression of FAM170B-AS1 was upregulated in sera of BC patients and hsa-miR-1202 was upregulated in sera of BBD and BC patients while that of hsa-miR-146a-5p was downregulated in BC. These FAM170B-AS1 was significantly associated with BC when compared to BBD. FAM170B-AS1 and hsa-miR-1202 were statistically associated with the BC's stage, grade, and LN metastasis. FAM170B-AS1 and hsa-miR-146a-5p gave the highest specificity and sensitivity for BC. KRAS and EGFR were predicted to be targeted by FAM170B-AS1 through interaction with hsa-miR-143-3p and hsa-miR-7-5p, respectively. Based on the TCGA database, cancer patients having mutations in FAM170B show good overall survival.

CONCLUSIONS

The present study reported that for the first time, FAM170B-AS1 may be a potential risk factor, predictive, and diagnostic marker for BC. In addition, FAM170B-AS1 might be involved in BC by interacting with hsa-miR-143-3p/KRAS and hsa-miR-7-5p/EGFR through enhancement or repression that may present a new therapeutic option for BC.

Decoding mitochondrial-nuclear (epi)genome interactions: the emerging role of ncRNAs

Bidirectional communication between the mitochondria and the nucleus is required for several physiological processes, and the nuclear epigenome is a key mediator of this relationship. ncRNAs are an emerging area of discussion for their roles in cellular function and regulation. In this review, we highlight the role of mitochondrial-encoded ncRNAs as mediators of communication between the mitochondria and the nuclear genome. We focus primarily on retrograde signaling, a process in which the mitochondrion relays ncRNAs to translate environmental stress signals to changes in nuclear gene expression, with implications on stress responses that may include disease(s). Other biological roles of mitochondrial-encoded ncRNAs, such as mitochondrial import of proteins and regulation of cell signaling, will also be discussed.

Regulatory Roles of Long Non-Coding RNAs Relevant to Antioxidant Enzymes and Immune Responses of Apis cerana Larvae Following Ascosphaera apis Invasion

Long non-coding RNAs (lncRNAs) play an essential part in controlling gene expression and a variety of biological processes such as immune defense and stress-response. However, whether and how lncRNAs regulate responses of Apis cerana larvae to Ascosphaera apis invasion has remained unclear until now. Here, the identification and structural analysis of lncRNAs in the guts of A. cerana worker larvae were conducted, and the expression profile of larval lncRNAs during the A. apis infection process was then analyzed, followed by an investigation of the regulatory roles of differentially expressed lncRNAs (DElncRNAs) in the host response. In total, 76 sense lncRNAs, 836 antisense lncRNAs, 184 intron lncRNAs, 362 bidirectional lncRNAs, and 2181 intron lncRNAs were discovered in the larval guts. Additionally, 30 known and 9 novel lncRNAs were potential precursors for 36 and 11 miRNAs, respectively. In the three comparison groups, 386, 351, and 272 DElncRNAs were respectively identified, indicating the change in the overall expression pattern of host lncRNAs following the A. apis invasion. Analysis of cis-acting effect showed that DElncRNAs in the 4-, 5-, and 6-day-old comparison groups putatively regulated 55, 30, and 20 up- and down-stream genes, respectively, which were involved in a series of crucial functional terms and pathways, such as MAPK signaling pathway, and cell process. Analysis showed that 31, 8, and 11 DElncRNAs as potential antisense lncRNAs may interact with 26, 8, and 9 sense-strand mRNAs. Moreover, investigation of the competing endogenous RNA (ceRNA) network indicated that 148, 283, and 257 DElncRNAs were putatively regulated. The expression of target genes by targeting corresponding DEmiRNAs included those associated with antioxidant enzymes and immune responses. These results suggested that DElncRNAs played a potential part in the larval guts responding to the A. apis infection through a cis-acting manner and ceRNA mechanisms. Our findings deepen our understanding of interactions between A. cerana larvae and A. apis and offer a basis for clarifying the DElncRNA-mediated mechanisms underlying the host response to fungal invasion.

Single-cell profiling of lncRNA expression during Ebola virus infection in rhesus macaques

Long non-coding RNAs (lncRNAs) are involved in numerous biological processes and are pivotal mediators of the immune response, yet little is known about their properties at the single-cell level. Here, we generate a multi-tissue bulk RNAseq dataset from Ebola virus (EBOV) infected and not-infected rhesus macaques and identified 3979 novel lncRNAs. To profile lncRNA expression dynamics in immune circulating single-cells during EBOV infection, we design a metric, Upsilon, to estimate cell-type specificity. Our analysis reveals that lncRNAs are expressed in fewer cells than protein-coding genes, but they are not expressed at lower levels nor are they more cell-type specific when expressed in the same number of cells. In addition, we observe that lncRNAs exhibit similar changes in expression patterns to those of protein-coding genes during EBOV infection, and are often co-expressed with known immune regulators. A few lncRNAs change expression specifically upon EBOV entry in the cell. This study sheds light on the differential features of lncRNAs and protein-coding genes and paves the way for future single-cell lncRNA studies.

lncRNA NORAD, soluble ICAM1 and their correlations may be related to the regulation of the tumor immune microenvironment in laryngeal squamous cell carcinoma (LSCC)

NORAD, non-coding RNA activated by DNA damage, is a Long non-coding RNA (lncRNA) transcript that modulates genome stability and has been reported to be dysregulated in different cancers. Although it has been reported to be upregulated in tumor cells mostly for solid organ cancers, it has also been reported to be downregulated in some cancers. Although the pathophysiological mechanism is not fully understood, a negative correlation between NORAD and intercellular cell adhesion molecule-1 (ICAM-1) has been shown in experimental models, but this situation has not been evaluated in terms of cancer. We aimed to evaluate the potential roles of these two biomarker candidates together and separately in the clinicopathological axis in Laryngeal squamous cell carcinoma (LSCC) in a case-control study setting. The interactions of NORAD and ICAM1 at the RNA level were evaluated interactively by the RIblast program. sICAM1 (soluble intercellular cell adhesion molecule-1) levels were determined by ELISA in one hundred and five individuals (forty-four LSCC, sixty-one control) and lncRNA NORAD expression in eighty-eight tissues (forty-four LSCC tumors, forty-four tumor-free surrounding tissues) was determined by Real-time PCR. While the energy treesholud was - 16 kcal/mol between NORAD and ICAM1, the total energy was 176.33 kcal/mol, and 9 base pair pairings from 4 critical points were detected. NORAD expression level was found to be higher in tumor surrounding tissue compared to tumor tissue, and sICAM1 was higher in the control group compared to LSCC (p = 0.004; p = 0.02). NORAD discreminte tumor surrounding tissue from tumor (AUC: 0.674; optimal sensitivity:87.50%; optimal specificity 54.55%; cut-off point as >1.58 fold change; P = 0.034). The sICAM1 level was found to be higher in the control (494,814 ± 93.64 ng/L) than LSCC (432.95 ± 93.64 ng/L) (p = 0.02). sICAM1 discreminte control group from LSCC (AUC: 0.624; optimal sensitivity 68,85%; optimal specificity 61,36%; cut-off point ≤115,0 ng/L; (p = 0.033). A very strong negative correlation was found between NORAD expression and patients' sICAM1 levels (r = -.967; n = 44; p = 0.033). sICAM1 levels were found to be 1.63 times higher in NORAD downregulated subjects compared to upregulated ones (p = 0.031). NORAD was 3.63 times higher in those with alcohol use, and sICAM 1 was 5.77 times higher in those without distant organ metastasis (p = 0.043; 0.004). The increased NORAD expression in the tumor microenvironment in LSCC, the activation of T cells via TCR signaling, and the decrease of sICAM in the control group in correlation with NORAD suggests that ICAM1 may be needed as a membrane protein in the tumor microenvironment. NORAD and ICAM1 may be functionally related to tumor microenvironment and immune control in LSCC.

Differential Expression of Non-Coding RNAs in Stem Cell Development and Therapeutics of Bone Disorders

Stem cells' self-renewal and multi-lineage differentiation are regulated by a complex network consisting of signaling factors, chromatin regulators, transcription factors, and non-coding RNAs (ncRNAs). Diverse role of ncRNAs in stem cell development and maintenance of bone homeostasis have been discovered recently. The ncRNAs, such as long non-coding RNAs, micro RNAs, circular RNAs, small interfering RNA, Piwi-interacting RNAs, etc., are not translated into proteins but act as essential epigenetic regulators in stem cells' self-renewal and differentiation. Different signaling pathways are monitored efficiently by the differential expression of ncRNAs, which function as regulatory elements in determining the fate of stem cells. In addition, several species of ncRNAs could serve as potential molecular biomarkers in early diagnosis of bone diseases, including osteoporosis, osteoarthritis, and bone cancers, ultimately leading to the development of new therapeutic strategies. This review aims to explore the specific roles of ncRNAs and their effective molecular mechanisms in the growth and development of stem cells, and in the regulation of osteoblast and osteoclast activities. Furthermore, we focus on and explore the association of altered ncRNA expression with stem cells and bone turnover.

Co-expression analysis of lncRNA and mRNA identifies potential adipogenesis regulatory non-coding RNAs involved in the transgenerational effects of tributyltin

The obesity epidemic is considered a global public health crisis, with an increase in caloric intake, sedentary lifestyles and/or genetic predispositions as contributing factors. Although the positive energy balance is one of the most significant causes of obesity, recent research has linked early exposure to Endocrine-Disrupting Chemicals (EDCs) such as the obesogen tributyltin (TBT) to the disease epidemic. In addition to their actions on the hormonal profile, EDCs can induce long-term changes in gene expression, possibly due to changes in epigenetic patterns. Long non-coding RNAs (lncRNAs) are epigenetic mediators that play important regulatory roles in several biological processes, through regulation of gene transcription and/or translation. In this study, we explored the differential expression of lncRNAs in gonadal white adipose tissue samples from adult male C57BL/6J F4 generation, female C57BL/6J offspring exposed (F0 generation) to 50 nM TBT or 0.1% DMSO (control of vehicle) via drinking water provided during pregnancy and lactation, analyzing RNA-seq data from a publicly available dataset (GSE105051). A total of 74 lncRNAs were differentially expressed (DE), 22 were up-regulated and 52 were down-regulated in the group whose F4 ancestor was exposed in utero to 50nM TBT when compared to those exposed to 0.1% DMSO (control). Regulation of DE lncRNAs and their potential partner genes in gonadal white adipose tissue of mice ancestrally exposed to EDC TBT may be related to the control of adipogenesis, as pathway enrichment analyses showed that these gene partners are mainly involved in the metabolism of lipids and glucose and in insulin-related pathways, which are essential for obesity onset and control.

Drugging non-coding RNAs-A new light of hope in senescence-related cancer therapy

Cancer is the most prevalent disease of concern worldwide for several decades. Diverse therapeutic aspects are in applications to control this phenomenal disease and also for decennaries. Among many causes and consequences of cancer, senescence has gained much interest in recent times. Senescence, also termed aging, is the natural process that induces cancer in neighboring cells through Senescence-Associated-Secretory Phenotypes (SASPs) production. As a cure or preventive measure of cancer progression, studies already light upon multiple proteins and their roles in associated pathways but the aspect of different non-coding RNAs (ncRNAs) is emerging recently and is under extensive research. Different approaches toward controlling senescence and inhibiting senescent cell accumulation are other aspects of cancer procurement. Thus, the role of ncRNA molecules in senescence and aging is getting much more interest as an alternate therapy for cancer treatment. In this review, at first, the roles of different ncRNAs related to several cellular processes are described. Then we tried to highlight the roles of different non-coding RNAs in senescence-induced cancer formation that extends with increasing age and emphasized non-coding RNAs as a therapeutic target solely or in combination with small molecules where drugging of small molecules targeting these non-coding RNAs can control cancer development.

LncRNA MSC-AS1, as an oncogene in melanoma, promotes the proliferation and glutaminolysis by regulating the miR-330-3p/YAP1 axis

Melanoma is a kind of aggressive skin neoplasms with high mortality. The purpose of this present research was to investigate the effects and potential mechanisms of long-noncoding RNA (lncRNA) MSC antisense RNA 1 (MSC-AS1) in melanoma. MSC-AS1, miR-330-3p and YAP1 expression levels in melanoma tissues and cells were assessed by quantitative real-time polymerase chain reaction. Melanoma cells were evaluated using cell count kit-8, clone formation and ELISA in vitro. The relationship among MSC-AS1, YAP1 and miR-330-3p was validated by pull-down and luciferase reporter assays. Finally, the role of MSC-AS1 in vivo was determined by the xenograft model. Results showed that lncRNA MSC-AS1 was upregulated in melanoma tissues and cells. High expression of MAS-AS1 was positively correlated with a poor prognosis. Pull-down and luciferase reporter demonstrated that miR-330-3p specifically binds directly to YAP1 and MSC-AS1, respectively. MSC-AS1 promoted the expression of YAP1 by downregulating miR-330-3p. Functional experiments suggested that knockdown of MSC-AS1 suppressed the proliferation of melanoma cells and decreased the levels of glutamine, glutamate and α-ketoglutarate, glutaminase and glutamine transporter alanine-serine-cysteine transporter 2. Upregulation of miR-330-3p alleviated the promotion effect of MSC-AS1 overexpression on the proliferation and glutaminolysis of melanoma cells. The above changes could be reversed by YAP1 overexpression. In addition, knockdown of MSC-AS1 dramatically restrained the growth of melanoma cells in xenograft model. In conclusion, our results revealed that MSC-AS1 facilitated the proliferation and glutaminolysis of melanoma cells by regulating miR-330-3p/YAP1 pathway, suggesting that MSC-AS1 could provide a new idea for the treatment of melanoma.

A novel regulated network mediated by downregulation HIF1A-AS2 lncRNA impairs placental angiogenesis by promoting ANGPTL4 expression in preeclampsia

Preeclampsia (PE) is the predominant medical condition leading to maternal and fetal mortality, and the lack of effective treatment increases its risk to the public health. Among the numerous predisposing factors, the ineffectual remodeling of the uterine spiral arteries, which can induce abnormal placental angiogenesis, has been focused to solve the pathogenesis of PE. According to the preceding research results, abnormal expression of long non-coding RNAs (lncRNA)s could be associated with the pathological changes inducing PE. To be more specific, lncRNA HIF1A-AS2 was proposed for its potential to participate in the molecular mechanisms underlying PE. In vitro, in trophoblast cell lines HTR-8/SVneo and human umbilical vein endothelial cells HUVECs, HIF1A-AS2 knockdown inhibited cell proliferation, migration and tube formation. Mechanistically, transcription factor FOXP1 could regulate the expression of HIF1A-AS2. Moreover, a series of assays, including RNA pull down and mass spectrometry, RNA immunoprecipitation and chromatin immunoprecipitation assay, revealed that HIF1A-AS2 interacted with Lamin A/C (LMNA) to inhibit ANGPTL4 expression in trophoblast cells, thus further participating in the progression of PE. Taken together, these findings suggested that further analysis on HIF1A-AS2 could contribute to the development of prospective therapeutic strategy for PE.

Epithelial cells-enriched lncRNA SNHG8 regulates chromatin condensation by binding to Histone H1s

Linker histone H1 proteins contain many variants in mammalian and can stabilize the condensed state of chromatin by binding to nucleosomes and promoting a more inaccessible structure of DNA. However, it is poorly understood how the binding of histone H1s to chromatin DNA is regulated. Screened as one of a collection of epithelial cells-enriched long non-coding RNAs (lncRNAs), here we found that small nucleolar RNA host gene 8 (SNHG8) is a chromatin-localized lncRNA and presents strong interaction and phase separation with histone H1 variants. Moreover, SNHG8 presents stronger ability to bind H1s than linker DNA, and outcompetes linker DNA for H1 binding. Consequently, loss of SNHG8 increases the amount of H1s that bind to chromatin, promotes chromatin condensation, and induces an epithelial differentiation-associated gene expression pattern. Collectively, our results propose that the highly abundant SNHG8 in epithelial cells keeps histone H1 variants out of nucleosome and its loss contributes to epithelial cell differentiation.

LPInsider: a webserver for lncRNA–protein interaction extraction from the literature

Background

Long non-coding RNA (LncRNA) plays important roles in physiological and pathological processes. Identifying LncRNA–protein interactions (LPIs) is essential to understand the molecular mechanism and infer the functions of lncRNAs. With the overwhelming size of the biomedical literature, extracting LPIs directly from the biomedical literature is essential, promising and challenging. However, there is no webserver of LPIs relationship extraction from literature.

Results

LPInsider is developed as the first webserver for extracting LPIs from biomedical literature texts based on multiple text features (semantic word vectors, syntactic structure vectors, distance vectors, and part of speech vectors) and logistic regression. LPInsider allows researchers to extract LPIs by uploading PMID, PMCID, PMID List, or biomedical text. A manually filtered and highly reliable LPI corpus is integrated in LPInsider. The performance of LPInsider is optimal by comprehensive experiment on different combinations of different feature and machine learning models.

Conclusions

LPInsider is an efficient analytical tool for LPIs that helps researchers to enhance their comprehension of lncRNAs from text mining, and also saving their time. In addition, LPInsider is freely accessible from http://www.csbg-jlu.info/LPInsider/ with no login requirement. The source code and LPIs corpus can be downloaded from https://github.com/qiufengdiewu/LPInsider.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12859-022-04665-3.

Ion channel long non-coding RNAs in neuropathic pain

Neuropathic pain is one of the primary forms of chronic pain and is the consequence of the somatosensory system's direct injury or disease. It is a relevant public health problem that affects about 10% of the world's general population. In neuropathic pain, alteration in neurotransmission occurs at various levels, including the dorsal root ganglia, the spinal cord, and the brain, resulting from the malfunction of diverse molecules such as receptors, ion channels, and elements of specific intracellular signaling pathways. In this context, there have been exciting advances in elucidating neuropathic pain's cellular and molecular mechanisms in the last decade, including the possible role that long non-coding RNAs (lncRNAs) may play, which open up new alternatives for the development of diagnostic and therapeutic strategies for this condition. This review focuses on recent studies associated with the possible relevance of lncRNAs in the development and maintenance of neuropathic pain through their actions on the functional expression of ion channels. Recognizing the changes in the function and spatio-temporal patterns of expression of these membrane proteins is crucial to understanding the control of neuronal excitability in chronic pain syndromes.

Integrative Analysis of lncRNA-mRNA Co-expression Provides Novel Insights Into the Regulation of Developmental Transitions in Female Varroa destructor

Varroa destructor is a major pathogenic driver of the Western honeybee colony losses globally. Understanding the developmental regulation of V. destructor is critical to develop effective control measures. Development is a complex biological process regulated by numerous genes and long non-coding RNAs (lncRNAs); however, the underlying regulation of lncRNAs in the development of V. destructor remains unknown. In this study, we analyzed the RNA sequencing (RNA-Seq) data derived from the four stages of female V. destructor in the reproductive phase (i.e., egg, protonymph, deutonymph, and adult). The identified differentially expressed mRNAs and lncRNAs exhibited a stage-specific pattern during developmental transitions. Further functional enrichment established that fat digestion and absorption, ATP-binding cassette (ABC) transporters, mitogen-activated protein kinase (MAPK) signaling pathway, and ubiquitin-proteasome pathway play key roles in the maturation of female V. destructor. Moreover, the lncRNAs and mRNAs of some pivotal genes were significantly upregulated at the deutonymph stage, such as cuticle protein 65/6.4/63/38 and mucin 5AC, suggesting that deutonymph is the key stage of metamorphosis development and pathogen resistance acquisition for female V. destructor. Our study provides novel insights into a foundational understanding of V. destructor biology.

Long Noncoding RNA Mediated Regulation in Human Embryogenesis, Pluripotency, and Reproduction

Long noncoding RNAs (lncRNAs), a class of noncoding RNAs with more than 200 bp in length, are produced by pervasive transcription in mammalian genomes and regulate gene expression through various action mechanisms. Accumulating data indicate that lncRNAs mediate essential biological functions in human development, including early embryogenesis, induction of pluripotency, and germ cell development. Comprehensive analysis of sequencing data highlights that lncRNAs are expressed in a stage-specific and human/primate-specific pattern during early human development. They contribute to cell fate determination through interacting with almost all classes of cellular biomolecules, including proteins, DNA, mRNAs, and microRNAs. Furthermore, the expression of a few of lncRNAs is highly associated with the pathogenesis and progression of many reproductive diseases, suggesting that they could serve as candidate biomarkers for diagnosis or novel targets for treatment. Here, we review research on lncRNAs and their roles in embryogenesis, pluripotency, and reproduction. We aim to identify the underlying molecular mechanisms essential for human development and provide novel insight into the causes and treatments of human reproductive diseases.

Illuminating lncRNA Function Through Target Prediction

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

Noncoding RNA Roles in Pharmacogenomic Responses to Aspirin: New Molecular Mechanisms for an Old Drug

Aspirin, as one of the most frequently prescribed drugs, can have therapeutic effects on different conditions such as cardiovascular and metabolic disorders and malignancies. The effects of this common cardiovascular drug are exerted through different molecular and cellular pathways. Altered noncoding RNA (ncRNA) expression profiles during aspirin treatments indicate a close relationship between these regulatory molecules and aspirin effects through regulating gene expressions. A better understanding of the molecular networks contributing to aspirin efficacy would help optimize efficient therapies for this very popular drug. This review is aimed at discussing and highlighting the identified interactions between aspirin and ncRNAs and their targeting pathways and better understanding pharmacogenetic responses to aspirin.

LncRNA miR205HG hinders HNRNPA0 translation: anti-oncogenic effects in esophageal carcinoma

Esophageal carcinoma (ESCA) affects 4 450 000 people and causes approximately 400 000 deaths annually worldwide, making it the sixth most lethal and eighth most common cancer. Patients with ESCA are often diagnosed at the later stages in which cancer cell metastasis is the main factor contributing to the low 5‐year survival rate (< 20%) of this disease. Long noncoding RNAs (lncRNAs) are a group of regulatory RNAs with a length of > 200 nucleotides but which fail to encode proteins. In this study, by using real‐time quantitative PCR, we found that the expression of the miR205 host gene (miR205HG; a lncRNA) was downregulated in ESCA tumors when compared with normal esophageal tissues or adjacent normal tissues of tumors. Furthermore, we demonstrated that miR205HG modulates the expression of extracellular matrix‐related genes in ESCA cells. In the transwell assay, downregulation of miR205HG contributes to migration and invasion of ESCA cells. In relation to the mechanism, our data show that miR205HG interacts with heterogeneous nuclear ribonucleoprotein A0 (HNRNPA0) mRNA and then hamper its translation by interacting with lin‐28 homolog A (LIN28A). Altogether, we highlight that the miR205HG‐HNRNPA0 axis is implicated in the migration and invasion of ESCA cells and that these members of this pathway may serve as therapeutic targets to inhibit metastasis of ESCA.

Pattern of Repetitive Element Transcription Segregate Cell Lineages during the Embryogenesis of Sea Urchin Strongylocentrotus purpuratus

Repetitive elements (REs) occupy a significant part of eukaryotic genomes and are shown to play diverse roles in genome regulation. During embryogenesis of the sea urchin, a large number of REs are expressed, but the role of these elements in the regulation of biological processes remains unknown. The aim of this study was to identify the RE expression at different stages of embryogenesis. REs occupied 44% of genomic DNA of Strongylocentrotus purpuratus. The most prevalent among these elements were the unknown elements-in total, they contributed 78.5% of REs (35% in total genome occupancy). It was revealed that the transcription pattern of genes and REs changes significantly during gastrulation. Using the de novo transcriptome assembly, we showed that the expression of RE is independent of its copy number in the genome. We also identified copies that are expressed. Only active RE copies were used for mapping and quantification of RE expression in the single-cell RNA sequencing data. REs expression was observed in all cell lineages and they were detected as population markers. Moreover, the primary mesenchyme cell (PMC) line had the greatest diversity of REs among the markers. Our data suggest a role for RE in the organization of developmental domains during the sea urchin embryogenesis at the single-cell resolution level.

Identification of Potential Long Non-Coding RNA Candidates that Contribute to Triple-Negative Breast Cancer in Humans through Computational Approach

Breast cancer (BC) is the most frequent malignancy identified in adult females, resulting in enormous financial losses worldwide. Owing to the heterogeneity as well as various molecular subtypes, the molecular pathways underlying carcinogenesis in various forms of BC are distinct. Therefore, the advancement of alternative therapy is required to combat the ailment. Recent analyses propose that long non-coding RNAs (lncRNAs) perform an essential function in controlling immune response, and therefore, may provide essential information about the disorder. However, their function in patients with triple-negative BC (TNBC) has not been explored in detail. Here, we analyzed the changes in the genomic expression of messenger RNA (mRNA) and lncRNA in standard control in response to cancer metastasis using publicly available single-cell RNA-Seq data. We identified a total of 197 potentially novel lncRNAs in TNBC patients of which 86 were differentially upregulated and 111 were differentially downregulated. In addition, among the 909 candidate lncRNA transcripts, 19 were significantly differentially expressed (DE) of which three were upregulated and 16 were downregulated. On the other hand, 1901 mRNA transcripts were significantly DE of which 1110 were upregulated and 791 were downregulated by TNBCs subtypes. The Gene Ontology (GO) analyses showed that some of the host genes were enriched in various biological, molecular, and cellular functions. The Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis showed that some of the genes were involved in only one pathway of prostate cancer. The lncRNA-miRNA-gene network analysis showed that the lncRNAs TCONS_00076394 and TCONS_00051377 interacted with breast cancer-related micro RNAs (miRNAs) and the host genes of these lncRNAs were also functionally related to breast cancer. Thus, this study provides novel lncRNAs as potential biomarkers for the therapeutic intervention of this cancer subtype.

The Role of Long Non-Coding RNAs in Endometriosis

Endometriosis is a chronic gynecological disorder affecting the quality of life and fertility of many women around the world. Heterogeneous and non-specific symptoms may lead to a delay in diagnosis, with treatment options limited to surgery and hormonal therapy. Hence, there is a need to better understand the pathogenesis of the disease to improve diagnosis and treatment. Long non-coding RNAs (lncRNAs) have been increasingly shown to be involved in gene regulation but remain relatively under investigated in endometriosis. Mutational and transcriptomic studies have implicated lncRNAs in the pathogenesis of endometriosis. Single-nucleotide polymorphisms (SNPs) in lncRNAs or their regulatory regions have been associated with endometriosis. Genome-wide transcriptomic studies have identified lncRNAs that show deregulated expression in endometriosis, some of which have been subjected to further experiments, which support a role in endometriosis. Mechanistic studies indicate that lncRNAs may regulate genes involved in endometriosis by acting as a molecular sponge for miRNAs, by directly targeting regulatory elements via interactions with chromatin or transcription factors or by affecting signaling pathways. Future studies should concentrate on determining the role of uncharacterized lncRNAs revealed by endometriosis transcriptome studies and the relevance of lncRNAs implicated in the disease by in vitro and animal model studies.

LncRNA H19 Regulates Proliferation, Apoptosis and ECM Degradation of Aortic Smooth Muscle Cells Via miR-1-3p/ADAM10 Axis in Thoracic Aortic Aneurysm

Thoracic aortic aneurysm (TAA) is a prevalent health problem worldwide. Long non-coding RNA H19was highly expressed in TAA patients, but the function and mechanism of H19 in TAA remain unknown. The expression levels of H19, microRNA-1-3p (miR-1-3p), and a disintegrin and metalloproteinase 10 (ADAM10) were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Receiver operating characteristic (ROS) cure was performed to evaluate the diagnostic value of H19 on TAA patients. Proliferation and apoptosis were detected by Cell Counting Kit-8 (CCK-8), colony formation, and flow cytometry. Protein levels of proliferating cell nuclear antigen (PCNA), Cleaved-caspase 3 (Cleaved-cas3), Cleaved-caspase 9 (Cleaved-cas9), Collagen I, Collagen III, and ADAM10 were tested by western blot assay. The binding relationship between miR-1-3p and H19 or ADAM10 was predicted by LncBase Predicted v.2 or Starbase, and verified by the dual-luciferase reporter, RNA pull-down assay, and RNA Immunoprecipitation (RIP) assays. H19 was increased in TAA aorta tissues and serum and vascular smooth muscle cell (VSMC), and hindered proliferation as well as promoted apoptosis and extracellular matrix (ECM) degradation of VSMC. Moreover, miR-1-3p was decreased, and ADAM10 was upregulated in TAA aorta tissues and VSMC. The mechanical analysis confirmed that H19 affected ADAM10 expression by targeting miR-1-3p. Our results indicated that H19 inhibited proliferation, and accelerated apoptosis and ECM degradation of VSMC, providing an underlying lncRNA-targeted therapy for TAA treatment.

Roles of miRNA and lncRNA in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is currently the most malignant subtype of breast cancer without effective targeted therapies, which makes its pathogenesis an important target for research. A growing number of studies have shown that non-coding RNA (ncRNA), including microRNA (miRNA) and long non-coding RNA (lncRNA), plays a significant role in tumorigenesis. This review summarizes the roles of miRNA and lncRNA in the progression, diagnosis, and neoadjuvant chemotherapy of TNBC. Aberrantly expressed miRNA and lncRNA are listed according to their roles. Further, it describes the multiple mechanisms that lncRNA shows for regulating gene expression in the nucleus and cytoplasm, and more importantly, describes lncRNA-regulated TNBC progression through complete combining with miRNA at the post-transcriptional level. Focusing on miRNA and lncRNA associated with TNBC can provide new insights for early diagnosis and treatment-they can be targeted in the future as a novel anticancer target of TNBC.

Long non-coding RNAs and their involvement in bipolar disorders

Non-coding RNAs (nc-RNAs) can be defined as RNA molecules that are not translated into proteins. Although the functional meaning of many nc-RNAs remains still to be verified, several of these molecules have a clear biological importance, which goes from translation of mRNAs to DNA replication. Indeed, regulatory nc-RNAs can be classified into two groups: short non-coding RNAs (sncRNAs) and long-non coding RNAs (lncRNAs). In the last years, lncRNAs have gained increasing importance in the study of gene regulation, helping authors understand the molecular mechanisms underlying cellular physiology and pathology. LncRNAs are greater than 200 bp and accumulate in nucleus, cytoplasm and exosomes with high tissue specificity, acting in cis or in trans in order to exert enhancer or silencer modulation on gene expression. Such regulatory features, which are widespread in human cells and tissues, can be disrupted in several morbid states. Recent evidences may suggest a disruption of lncRNAs in bipolar disorders, a cluster of severe, chronic and disabling psychiatric diseases, which are characterized by major depressive states cyclically alternating with manic episodes. Here, the authors reviewed genes, classification, biogenesis, structures, functions and databases regarding lncRNAs, and also focused on bipolar disorders, in which some lncRNAs, especially those involved in inflammation and neuronal development, has reported to be dysregulated.

Expression and prognostic relevance of long noncoding RNAs CRNDE and AOX2P in adult acute myeloid leukemia

INTRODUCTION

Several long noncoding RNAs (lncRNAs) have been demonstrated to play a critical role in the tumorigenesis of acute myeloid leukemia (AML), and altered expression of certain lncRNAs has been recognized as a potential prognostic marker in AML patients. Here, we sought to determine whether the expression of the lncRNA colorectal neoplasia differentially expressed (CRNDE) and aldehyde oxidase 2 pseudogene (AOX2P) is associated with clinicopathological features and clinical outcome of patients with AML.

METHODS

CRNDE and AOX2P expression levels were measured in diagnostic blood samples from 200 adult patients with de novo AML, along with 50 healthy control blood samples, using quantitative real-time polymerase chain reaction (qRT-PCR). The association of CRNDE and AOX2P expression with the clinicopathological characteristics and outcome of AML patients was analyzed.

RESULTS

Upregulated CRNDE expression was independently associated with lower complete remission (CR) rates in the whole cohort of AML (P < .001). AOX2P overexpression was identified as an independent adverse prognostic marker for CR in the CN-AML (P = .009) and non-t (15;17) AML (P < .001) subgroups. Patients with high CRNDE expression had a significantly shorter event-free survival (EFS, whole cohort of AML: P = .017; CN-AML: P = .001; non-t (15;17) AML: P = .006) and inferior overall survival (OS, whole cohort of AML: P = .002; t(15;17) AML: P = .001) than those with low CRNDE expression. EFS and OS did not differ significantly between patients with high AOX2P expression and those with low expression.

CONCLUSION

Aberrantly upregulated CRNDE expression and, to a lesser extent, AOX2P overexpression, are associated with poor prognosis in AML patients, suggesting that the determination of CRNDE and, perhaps, AOX2P, expression level at diagnosis provides valuable prognostic information, allows refinement of risk stratification, and helps clinical decision-making in AML.

Regulation of Hippo, TGFβ/SMAD, Wnt/β-Catenin, JAK/STAT, and NOTCH by Long Non-Coding RNAs in Pancreatic Cancer

Rapidly evolving and ever-increasing knowledge of the molecular pathophysiology of pancreatic cancer has leveraged our understanding altogether to a next level. Compared to the exciting ground-breaking discoveries related to underlying mechanisms of pancreatic cancer onset and progression, however, there had been relatively few advances in the therapeutic options available for the treatment. Since the discovery of the DNA structure as a helix which replicates semi-conservatively to pass the genetic material to the progeny, there has been conceptual refinement and continuous addition of missing pieces to complete the landscape of central dogma. Starting from transcription to translation, modern era has witnessed non-coding RNA discovery and central role of these versatile regulators in onset and progression of pancreatic cancer. Long non-coding RNAs (lncRNAs) have been shown to act as competitive endogenous RNAs through sequestration and competitive binding to myriad of microRNAs in different cancers. In this article, we set spotlight on emerging evidence of regulation of different signaling pathways (Hippo, TGFβ/SMAD, Wnt/β-Catenin, JAK/STAT and NOTCH) by lncRNAs. Conceptual refinements have enabled us to understand how lncRNAs play central role in post-translational modifications of various proteins and how lncRNAs work with epigenetic-associated machinery to transcriptionally regulate gene network in pancreatic cancer.

Long non-coding RNA H19: Physiological functions and involvements in central nervous system disorders

Central nervous system (CNS) disorders are some of the most complex and challenging diseases because of the intricate structure and functions of the CNS. Long non-coding RNA (LncRNA) H19, which had been mistaken for "transcription noise" previously, has now been found to be closely related to the development and homeostasis of the CNS. Several recent studies indicate that it plays an important role in the pathogenesis, treatment, and even prognosis of CNS disorders. LncRNA H19 is correlated with susceptibility to various CNS disorders such as intracranial aneurysms, ischemic stroke, glioma, and neuroblastoma. Moreover, it participates in the pathogenesis of CNS disorders by regulating transcription, translation, and signaling pathways, suggesting that it is a promising biomarker and therapeutic target for these disorders. This article reviews the functions and mechanisms of lncRNA H19 in various CNS disorders, including cerebral ischemia, cerebral hemorrhage, glioma, pituitary adenoma, neuroblastoma, Parkinson's disease, Alzheimer's disease, traumatic spinal cord injury, neuropathic pain, and temporal lobe epilepsy, to provide a theoretical basis for further research on the role of lncRNA H19 in CNS disorders.

New epigenetic players in stroke pathogenesis: From non-coding RNAs to exosomal non-coding RNAs

Non-coding RNAs (ncRNAs) have critical role in the pathophysiology as well as recovery after ischemic stroke. ncRNAs, particularly microRNAs, and the long non-coding RNAs (lncRNAs) are critical for angiogenesis and neuroprotection, and they have been suggested to be therapeutic, diagnostic and prognostic tools in cerebrovascular diseases, including stroke. Moreover, exosomes have been considered as nanocarriers capable of transferring various cargos, such as lncRNAs and miRNAs to recipient cells, with prominent inter-cellular roles in the mediation of neuro-restorative events following strokes and neural injuries. In this review, we summarize the pathogenic role of ncRNAs and exosomal ncRNAs in the stroke.

Recent Advances of MicroRNAs, Long Non-coding RNAs, and Circular RNAs in Preeclampsia

Preeclampsia is a clinical syndrome characterized by multiple-organ dysfunction, such as maternal hypertension and proteinuria, after 20 weeks of gestation. It is a common cause of fetal growth restriction, fetal malformation, and maternal death. At present, termination of pregnancy is the only way to prevent the development of the disease. Non-coding RNAs, including microRNAs, long non-coding RNAs, and circular RNAs, are involved in important pathological and physiological functions in life cycle activities including ontogeny, reproduction, apoptosis, and cell reprogramming, and are closely associated with human diseases. Accumulating evidence suggests that non-coding RNAs are involved in the pathogenesis of preeclampsia through regulation of various physiological functions. In this review, we discuss the current evidence of the pathogenesis of preeclampsia, introduce the types and biological functions of non-coding RNA, and summarize the roles of non-coding RNA in the pathophysiological development of preeclampsia from the perspectives of oxidative stress, hypoxia, angiogenesis, decidualization, trophoblast invasion and proliferation, immune regulation, and inflammation. Finally, we briefly discuss the potential clinical application and future prospects of non-coding RNA as a biomarker for the diagnosis of preeclampsia.

Suppression of choroidal neovascularization by silencing of long non-coding RNA IPW

Long noncoding RNAs (lncRNAs) have emerged as the key regulators in the pathogenesis of human disorders. This study aimed to investigate the role of lncRNA-IPW in the progression of choroidal neovascularization (CNV) and the underlying molecular mechanism. IPW was significantly up-regulated in the choroidal tissues of laser-induced CNV mice and in the endothelial cells in response to hypoxic stress. IPW silencing led to reduced formation of CNV in laser-induced CNV model and ex vivo choroidal sprouting model, which could achieve similar therapeutic effects of anti-VEGF on CNV formation. Silencing or transgenic overexpression of IPW could alter endothelial cell viability, proliferation, migration, and tube formation ability in vitro. Mechanistically, IPW silencing led to increased expression of miR-370. Increased miR-370 could mimic the effects of IPW silencing on CNV formation and endothelial angiogenic phenotypes in vivo and in vitro. This study suggests that IPW silencing is a promising strategy for the treatment of neovascular ocular diseases.

Knockdown of Nuclear lncRNAs by Locked Nucleic Acid (LNA) Gapmers in Nephron Progenitor Cells

Despite recent advance in our understanding on the role of long noncoding RNAs (lncRNAs), the function of the vast majority of lncRNAs remains poorly understood. To characterize the function of lncRNAs, knockdown studies are essential. However, the conventional silencing methods for mRNA, such as RNA interference (RNAi), may not be as efficient against lncRNAs, partly due to the mismatch of the localization of lncRNAs and RNAi machinery. To circumvent such limitation, a new technique has recently been developed, i.e., locked nucleic acid (LNA) gapmers. This system utilizes RNase H that distributes evenly in both nucleus and cytoplasm and is expected to knock down lncRNAs of interest more consistently regardless of their localization in the cell. In this chapter, we describe the procedure with tips to silence lncRNAs by LNA gapmers, by using mouse nephron progenitor cells as an example.

Long non-coding RNA-regulated pathways in pancreatic β cells: Their role in diabetes

Long non-coding RNAs (lncRNAs) are transcripts of more than 200 nucleotides that have not coding potential, but act as gene expression regulators through several molecular mechanisms. Several studies have identified tons of lncRNAs that are expressed in pancreatic β cells and many of them have been shown to have β cell-specific expression, suggesting a potential role in the regulation of basal β cell functions. Indeed, accumulating evidence based on numerous studies, has highlighted the implication of lncRNAs in the regulation of pancreatic β cell differentiation and proliferation, insulin synthesis and secretion, and apoptosis. In addition, several lncRNAs have shown to be implicated in pancreatic β cell dysfunction linked to different types of diabetes, including type 1 and type 2 diabetes, and monogenic forms of the disease. Pathogenic conditions linked to diabetes (inflammation or lipoglucotoxicity, for example) dysregulate the expression of several lncRNAs, suggesting that changes in lncRNA may alter potentially important pathways for β cell function, and eventually leading to β cell dysfunction and diabetes development. In this sense, functional characterization of some lncRNAs has demonstrated that these non-coding molecules participate in the regulation of several crucial pathways at the pancreatic β cell level, and dysregulation of these pathways leads to pathogenic phenotypes. In this review, we provide an overview of the action mechanisms of functionally characterized lncRNAs in healthy β cells and describe the contribution of some diabetes-associated lncRNAs to pancreatic β cell failure.

The Roles of Epigenetics Regulation in Bone Metabolism and Osteoporosis

Osteoporosis is a metabolic disease characterized by decreased bone mineral density and the destruction of bone microstructure, which can lead to increased bone fragility and risk of fracture. In recent years, with the deepening of the research on the pathological mechanism of osteoporosis, the research on epigenetics has made significant progress. Epigenetics refers to changes in gene expression levels that are not caused by changes in gene sequences, mainly including DNA methylation, histone modification, and non-coding RNAs (lncRNA, microRNA, and circRNA). Epigenetics play mainly a post-transcriptional regulatory role and have important functions in the biological signal regulatory network. Studies have shown that epigenetic mechanisms are closely related to osteogenic differentiation, osteogenesis, bone remodeling and other bone metabolism-related processes. Abnormal epigenetic regulation can lead to a series of bone metabolism-related diseases, such as osteoporosis. Considering the important role of epigenetic mechanisms in the regulation of bone metabolism, we mainly review the research progress on epigenetic mechanisms (DNA methylation, histone modification, and non-coding RNAs) in the osteogenic differentiation and the pathogenesis of osteoporosis to provide a new direction for the treatment of bone metabolism-related diseases.

Transposable element-derived sequences in vertebrate development

Transposable elements (TEs) are major components of all vertebrate genomes that can cause deleterious insertions and genomic instability. However, depending on the specific genomic context of their insertion site, TE sequences can sometimes get positively selected, leading to what are called "exaptation" events. TE sequence exaptation constitutes an important source of novelties for gene, genome and organism evolution, giving rise to new regulatory sequences, protein-coding exons/genes and non-coding RNAs, which can play various roles beneficial to the host. In this review, we focus on the development of vertebrates, which present many derived traits such as bones, adaptive immunity and a complex brain. We illustrate how TE-derived sequences have given rise to developmental innovations in vertebrates and how they thereby contributed to the evolutionary success of this lineage.

A novel long intergenic non-coding RNA, Nostrill, regulates iNOS gene transcription and neurotoxicity in microglia

BACKGROUND

Microglia are resident immunocompetent and phagocytic cells in the CNS. Pro-inflammatory microglia, stimulated by microbial signals such as bacterial lipopolysaccharide (LPS), viral RNAs, or inflammatory cytokines, are neurotoxic and associated with pathogenesis of several neurodegenerative diseases. Long non-coding RNAs (lncRNA) are emerging as important tissue-specific regulatory molecules directing cell differentiation and functional states and may help direct proinflammatory responses of microglia. Characterization of lncRNAs upregulated in proinflammatory microglia, such as NR_126553 or 2500002B13Rik, now termed Nostrill (iNOS Transcriptional Regulatory Intergenic LncRNA Locus) increases our understanding of molecular mechanisms in CNS innate immunity.

METHODS

Microglial gene expression array analyses and qRT-PCR were used to identify a novel long intergenic non-coding RNA, Nostrill, upregulated in LPS-stimulated microglial cell lines, LPS-stimulated primary microglia, and LPS-injected mouse cortical tissue. Silencing and overexpression studies, RNA immunoprecipitation, chromatin immunoprecipitation, chromatin isolation by RNA purification assays, and qRT-PCR were used to study the function of this long non-coding RNA in microglia. In vitro assays were used to examine the effects of silencing the novel long non-coding RNA in LPS-stimulated microglia on neurotoxicity.

RESULTS

We report here characterization of intergenic lncRNA, NR_126553, or 2500002B13Rik now termed Nostrill (iNOS Transcriptional Regulatory Intergenic LncRNA Locus). Nostrill is induced by LPS stimulation in BV2 cells, primary murine microglia, and in cortical tissue of LPS-injected mice. Induction of Nostrill is NF-κB dependent and silencing of Nostrill decreased inducible nitric oxide synthase (iNOS) expression and nitric oxide (NO) production in BV2 and primary microglial cells. Overexpression of Nostrill increased iNOS expression and NO production. RNA immunoprecipitation assays demonstrated that Nostrill is physically associated with NF-κB subunit p65 following LPS stimulation. Silencing of Nostrill significantly reduced NF-κB p65 and RNA polymerase II recruitment to the iNOS promoter and decreased H3K4me3 activating histone modifications at iNOS gene loci. In vitro studies demonstrated that silencing of Nostrill in microglia reduced LPS-stimulated microglial neurotoxicity.

CONCLUSIONS

Our data indicate a new regulatory role of the NF-κB-induced Nostrill and suggest that Nostrill acts as a co-activator of transcription of iNOS resulting in the production of nitric oxide by microglia through modulation of epigenetic chromatin remodeling. Nostrill may be a target for reducing the neurotoxicity associated with iNOS-mediated inflammatory processes in microglia during neurodegeneration.

Emerging Roles of Long Non-Coding RNAs in Diabetic Foot Ulcers

Diabetes mellitus is one of the most widespread metabolic diseases in the world, and diabetic foot ulcer (DFU), as one of its chronic complications, not only causes a large amount of physiological and psychological pain to patients but also places a tremendous burden on the entire economy and society. Despite significant advances in knowledge on the mechanism and in the treatment of DFU, clinical practice is still not satisfactory, and our understanding of its cellular and molecular pathogenesis is far from complete. Fortunately, progress in studying the roles of long non-coding RNAs (lncRNAs), which play important regulatory roles in the expression of genes at multiple levels, suggests that we can apply them in the early diagnosis and potential targeted intervention of DFU. In this review, we briefly summarize the current knowledge regarding the functional roles and potential mechanisms of reported lncRNAs in regulating DFU.

Evolution of Genome-Organizing Long Non-coding RNAs in Metazoans

Long non-coding RNAs (lncRNAs) have important regulatory functions across eukarya. It is now clear that many of these functions are related to gene expression regulation through their capacity to recruit epigenetic modifiers and establish chromatin interactions. Several lncRNAs have been recently shown to participate in modulating chromatin within the spatial organization of the genome in the three-dimensional space of the nucleus. The identification of lncRNA candidates is challenging, as it is their functional characterization. Conservation signatures of lncRNAs are different from those of protein-coding genes, making identifying lncRNAs under selection a difficult task, and the homology between lncRNAs may not be readily apparent. Here, we review the evidence for these higher-order genome organization functions of lncRNAs in animals and the evolutionary signatures they display.