HOXD-AS1 is a novel lncRNA encoded in HOXD cluster and a marker of neuroblastoma progression revealed via integrative analysis of noncoding transcriptome

Long non-coding RNAs in cancer: multifaceted roles and potential targets for immunotherapy

Cancer remains a major global health concern with high mortality rates mainly due to late diagnosis and poor prognosis. Long non-coding RNAs (lncRNAs) are emerging as key regulators of gene expression in human cancer, functioning through various mechanisms including as competing endogenous RNAs (ceRNAs) and indirectly regulating miRNA expression. LncRNAs have been found to have both oncogenic and tumor-suppressive roles in cancer, with the former promoting cancer cell proliferation, migration, invasion, and poor prognosis. Recent research has shown that lncRNAs are expressed in various immune cells and are involved in cancer cell immune escape and the modulation of the tumor microenvironment, thus highlighting their potential as targets for cancer immunotherapy. Targeting lncRNAs in cancer or immune cells could enhance the anti-tumor immune response and improve cancer immunotherapy outcomes. However, further research is required to fully understand the functional roles of lncRNAs in cancer and the immune system and their potential as targets for cancer immunotherapy. This review offers a comprehensive examination of the multifaceted roles of lncRNAs in human cancers, with a focus on their potential as targets for cancer immunotherapy. By exploring the intricate mechanisms underlying lncRNA-mediated regulation of cancer cell proliferation, invasion, and immune evasion, we provide insights into the diverse therapeutic applications of these molecules.

Long Non-Coding RNAs in Neuroblastoma: Pathogenesis, Biomarkers and Therapeutic Targets

Neuroblastoma is the most common malignant extracranial solid tumor of childhood. Recent studies involving the application of advanced high-throughput "omics" techniques have revealed numerous genomic alterations, including aberrant coding-gene transcript levels and dysfunctional pathways, that drive the onset, growth, progression, and treatment resistance of neuroblastoma. Research conducted in the past decade has shown that long non-coding RNAs, once thought to be transcriptomic noise, play key roles in cancer development. With the recent and continuing increase in the amount of evidence for the underlying roles of long non-coding RNAs in neuroblastoma, the potential clinical implications of these RNAs cannot be ignored. In this review, we discuss their biological mechanisms of action in the context of the central driving mechanisms of neuroblastoma, focusing on potential contributions to the diagnosis, prognosis, and treatment of this disease. We also aim to provide a clear, integrated picture of future research opportunities.

HAGLR, stabilized by m6A modification, triggers PTEN-Akt signaling cascade-mediated RPE cell pyroptosis via sponging miR-106b-5p

Consistent hyperglycaemia on retinal microvascular tissues is recognized as a vital inducer of diabetic retinopathy (DR) pathogenesis. In view of the essential functionality of long noncoding RNAs (lncRNAs) in multiple human diseases, we aim to figure out the exact role and underlying mechanisms of lncRNA HOXD Cluster Antisense RNA 1 (HAGLR) in DR pathogenesis. Serum specimens from patients with proliferative DR and healthy volunteers were collected for measuring HAGLR levels. Human primary retinal pigment epithelium (HRPE) cells kept in high glucose (HG) condition were applied to simulating hyperglycaemia of DR pathology in vitro. Cell proliferation, apoptosis, either pyroptosis was assess using Cell Counting Kit-8 TUNEL, flow cytometry, and enzyme-linked immunoassay assays. Bioinformatics analysis was subjected to examine the interaction between HAGLR and N6-methyladenosine (m6A)-bind protein IGF2BP2, as determined using RNA immunoprecipitation and RNA pull-down. Luciferase reporter assay was performed to assess the HAGLR-miR-106b-5p-PTEN axis. Levels of pyroptosis-associated biomarkers were detected using western blotting. Aberrantly overexpressed HAGLR was uncovered in the serum samples of DR patients and HG-induced HRPE cells, of which knockdown attenuated HG-induced cytotoxic impacts on cell apoptosis and pyroptosis. Whereas, reinforced HAGLR further aggravated these effects. IGF2BP2 positively regulated HAGLR in a m6A-dependent manner. HAGLR served as a sponge for miR-106b-5p to upregulate PTEN, thereby activating Akt signaling cascade. Rescue assays demonstrated that PTEN overexpression abolished the inhibition of silenced HAGLR on pyroptosis in HRPE cells. HAGLR, epigenetically modified by IGF2BP2 in an m6A-dependent manner, functioned as a sponge for miR-106b-5p, thereby activating PTEN/Akt signaling cascade to accelerate DR pathology.

NLR family pyrin domain containing 3 (NLRP3) inflammasomes and peripheral neuropathic pain - Emphasis on microRNAs (miRNAs) as important regulators

Neuropathic pain is caused by the lesion or disease of the somatosensory system and can be initiated and/or maintained by both central and peripheral mechanisms. Nerve injury leads to neuronal damage and apoptosis associated with the release of an array of pathogen- or damage-associated molecular patterns to activate inflammasomes. The activation of the NLR family pyrin domain containing 3 (NLRP3) inflammasome contributes to neuropathic pain and may represent a novel target for pain therapeutic development. In the current review, we provide an up-to-date summary of the recent findings on the involvement of NLRP3 inflammasome in modulating neuropathic pain development and maintenance, focusing on peripheral neuropathic conditions. Here we provide a detailed review of the mechanisms whereby NLRP3 inflammasomes contribute to neuropathic pain via (1) neuroinflammation, (2) apoptosis, (3) pyroptosis, (4) proinflammatory cytokine release, (5) mitochondrial dysfunction, and (6) oxidative stress. We then present the current research literature reporting on the antinociceptive effects of several natural products and pharmacological interventions that target activation, expression, and/or regulation of NLRP3 inflammasome. Furthermore, we emphasize the effects of microRNAs as another regulator of NLRP3 inflammasome. In conclusion, we summarize the possible caveats and future perspectives that might provide successful therapeutic approaches against NLRP3 inflammasome for treating or preventing neuropathic pain conditions.

lncRNAs-EZH2 interaction as promising therapeutic target in cutaneous melanoma

Melanoma is the most lethal skin cancer with increasing incidence worldwide. Despite a great improvement of diagnostics and treatment of melanoma patients, this disease is still a serious clinical problem. Therefore, novel druggable targets are in focus of research. EZH2 is a component of the PRC2 protein complex that mediates epigenetic silencing of target genes. Several mutations activating EZH2 have been identified in melanoma, which contributes to aberrant gene silencing during tumor progression. Emerging evidence indicates that long non-coding RNAs (lncRNAs) are molecular "address codes" for EZH2 silencing specificity, and targeting lncRNAs-EZH2 interaction may slow down the progression of many solid cancers, including melanoma. This review summarizes current knowledge regarding the involvement of lncRNAs in EZH2-mediated gene silencing in melanoma. The possibility of blocking lncRNAs-EZH2 interaction in melanoma as a novel therapeutic option and plausible controversies and drawbacks of this approach are also briefly discussed.

Long Non-coding RNAs and CRISPR-Cas Edition in Tumorigenesis

Long non-coding RNAs (lncRNAs) are one of the most abundant and heterogeneous transcripts with key roles in chromatin remodeling and gene regulation at the transcriptional and post-transcriptional levels. Due to their role in cell growth and differentiation, lncRNAs have emerged as an important biomarker in cancer diagnosis, prognosis, and targeted treatment. Recent studies have focused on elucidating lncRNA function during malignant transformation, tumor progression and drug resistance. The advent of the CRISPR system has made it possible to precisely edit complex genomic loci such as lncRNAs. Thus, we summarized the advances in CRISPR-Cas approaches for functional studies of lncRNAs including gene knockout, knockdown, overexpression and RNA targeting in tumorigenesis and drug resistance. Additionally, we highlighted the perspectives and potential applications of CRISPR approaches to treat cancer, as an emerging and promising target therapy.

Pediatric Pan-Central Nervous System Tumor Methylome Analyses Reveal Immune-Related LncRNAs

Pediatric central nervous system (CNS) tumors are the second most common cancer diagnosis among children. Long noncoding RNAs (lncRNAs) emerge as critical regulators of gene expression, and they play fundamental roles in immune regulation. However, knowledge on epigenetic changes in lncRNAs in diverse types of pediatric CNS tumors is lacking. Here, we integrated the DNA methylation profiles of 2,257 pediatric CNS tumors across 61 subtypes with lncRNA annotations and presented the epigenetically regulated landscape of lncRNAs. We revealed the prevalent lncRNA methylation heterogeneity across pediatric pan-CNS tumors. Based on lncRNA methylation profiles, we refined 14 lncRNA methylation clusters with distinct immune microenvironment patterns. Moreover, we found that lncRNA methylations were significantly correlated with immune cell infiltrations in diverse tumor subtypes. Immune-related lncRNAs were further identified by investigating their correlation with immune cell infiltrations and potentially regulated target genes. LncRNA with methylation perturbations potentially regulate the genes in immune-related pathways. We finally identified several candidate immune-related lncRNA biomarkers (i.e., SSTR5-AS1, CNTN4-AS1, and OSTM1-AS1) in pediatric cancer for further functional validation. In summary, our study represents a comprehensive repertoire of epigenetically regulated immune-related lncRNAs in pediatric pan-CNS tumors, and will facilitate the development of immunotherapeutic targets.

The role of ncRNAs in neuroblastoma: mechanisms, biomarkers and therapeutic targets

Neuroblastoma (NB) is a malignant tumor in young children that originates from the neural crest of the sympathetic nervous system. Generally, NB occurs in the adrenal glands, but it can also affect the nerve tissues of the neck, chest, abdomen, and pelvis. Understanding the pathophysiology of NB and developing novel therapeutic approaches are critical. Noncoding RNAs (ncRNAs) are associated with crucial aspects of pathology, metastasis and drug resistance in NB. Here, we summarized the pretranscriptional, transcriptional and posttranscriptional regulatory mechanisms of ncRNAs involved in NB, especially focusing on regulatory pathways. Furthermore, ncRNAs with the potential to serve as biomarkers for risk stratification, drug resistance and therapeutic targets are also discussed, highlighting the clinical application of ncRNAs in NB.

There and Back Again: Hox Clusters Use Both DNA Strands

Bilaterian animals operate the clusters of Hox genes through a rich repertoire of diverse mechanisms. In this review, we will summarize and analyze the accumulated data concerning long non-coding RNAs (lncRNAs) that are transcribed from sense (coding) DNA strands of Hox clusters. It was shown that antisense regulatory RNAs control the work of Hox genes in cis and trans, participate in the establishment and maintenance of the epigenetic code of Hox loci, and can even serve as a source of regulatory peptides that switch cellular energetic metabolism. Moreover, these molecules can be considered as a force that consolidates the cluster into a single whole. We will discuss the examples of antisense transcription of Hox genes in well-studied systems (cell cultures, morphogenesis of vertebrates) and bear upon some interesting examples of antisense Hox RNAs in non-model Protostomia.

Deciphering the Long Non-Coding RNAs and MicroRNAs Coregulation Networks in Ovarian Cancer Development: An Overview

Non-coding RNAs are emergent elements from the genome, which do not encode for proteins but have relevant cellular functions impacting almost all the physiological processes occurring in eukaryotic cells. In particular, microRNAs and long non-coding RNAs (lncRNAs) are a new class of small RNAs transcribed from the genome, which modulate the expression of specific genes at transcriptional and posttranscriptional levels, thus adding a new regulatory layer in the flux of genetic information. In cancer cells, the miRNAs and lncRNAs interactions with its target genes and functional pathways are deregulated as a consequence of epigenetic and genetic alterations occurring during tumorigenesis. In this review, we summarize the actual knowledge on the interplay of lncRNAs with its cognate miRNAs and mRNAs pairs, which interact in coregulatory networks with a particular emphasis on the mechanisms underlying its oncogenic behavior in ovarian cancer. Specifically, we reviewed here the evidences unraveling the relevant roles of lncRNAs/miRNAs pairs in altered regulation of cell migration, angiogenesis, therapy resistance, and Warburg effect. Finally, we also discussed its potential clinical implications in ovarian cancer and related endocrine disease therapies.

Non-Coding RNAs Participate in the Pathogenesis of Neuroblastoma

Neuroblastoma is one of the utmost frequent neoplasms during the first year of life. This pediatric cancer is believed to be originated during the embryonic life from the neural crest cells. Previous studies have detected several types of chromosomal aberrations in this tumor. More recent studies have emphasized on expression profiling of neuroblastoma samples to identify the dysregulated genes in this type of cancer. Non-coding RNAs are among the mostly dysregulated genes in this type of cancer. Such dysregulation has been associated with a number of chromosomal aberrations that are frequently detected in neuroblastoma. In this study, we explain the role of non-coding transcripts in the malignant transformation in neuroblastoma and their role as biomarkers for this pediatric cancer.

HAGLR aggravates neuropathic pain and promotes inflammatory response and apoptosis of lipopolysaccharide-treated SH-SY5Y cells by sequestering miR-182-5p from ATAT1 and activating NLRP3 inflammasome

BACKGROUND

Chronic neuropathic pain is characterized by neuroinflammation. Previously, long noncoding RNA (lncRNA) HAGLR was reported to regulate the inflammatory response of SH-SY5Y cells. However, neither the specific function nor the potential mechanism of HAGLR in neuropathic pain has been explored.

AIM OF THE STUDY

Our study is aimed to figure out the role of HAGLR in neuropathic pain.

METHODS

SH-SY5Y cells were treated with lipopolysaccharide (LPS) to mimic neuron injury in vitro. The chronic constriction injury (CCI) rat models were established by ligation of sciatic nerve to mimic neuropathic pain in vivo. Behavioral assessment assays were performed to determine the effects of HAGLR on hypersensitivity in neuropathic pain. Enzyme-linked immunosorbent assay kits were used for detection of inflammatory cytokines. Flow cytometry analysis and Western blot were applied to detect apoptosis.

RESULTS

HAGLR displayed high levels in spinal cords of CCI rats and in LPS treated SH-SY5Y cells. Knockdown of HAGLR inhibited inflammation and neuron apoptosis of LPS treated SH-SY5Y cells. Mechanistically, HAGLR bound with miR-182-5p in SH-SY5Y cells. ATAT1 served as a target of miR-182-5p. HAGLR activated the NLRP3 inflammasome by ATAT1. Rescue assays demonstrated that overexpression of ATAT1 or NLRP3 reversed the suppressive effects of HAGLR silencing on apoptosis and inflammatory response in SH-SY5Y cells and in spinal cords of CCI rats. The inhibitory effects of silenced HAGLR on hypersensitivity in neuropathic pain were also rescued by ATAT1 or NLRP3.

CONCLUSIONS

HAGLR aggravates neuropathic pain by sequestering miR-182-5p from ATAT1 and activating NLRP3 inflammasome, which may provide a potential therapeutic target for neuropathic pain treatment.

LncRNAs and Immunity: Coding the Immune System with Noncoding Oligonucleotides

Long noncoding RNAs (lncRNAs) represent key regulators of gene transcription during the inflammatory response. Recent findings showed lncRNAs to be dysregulated in human diseases, such as inflammatory bowel disease, diabetes, allergies, asthma, and cancer. These noncoding RNAs are crucial for immune mechanism, as they are involved in differentiation, cell migration and in the production of inflammatory mediators through regulating protein–protein interactions or their ability to assemble with RNA and DNA. The last interaction can occur in cis or trans and is responsible for all the possible lncRNAs biological effects. Our proposal is to provide an overview on lncRNAs roles and functions related to immunity and immune mediated diseases, since these elucidations could be beneficial to untangle the complex bond between them.

Long noncoding RNA LINC01410 promotes the tumorigenesis of neuroblastoma cells by sponging microRNA-506-3p and modulating WEE1

OBJECTIVE

Neuroblastoma (NBL) is an extra-cranial solid tumor in children. This study was attempted to investigate the regulatory mechanism of long noncoding RNA LINC01410 (LINC01410) on NBL.

METHODS

The expression of LINC01410, miR-506-3p, and WEE1 in NBL was evaluated by quantitative real time polymerase chain reaction. The proliferation and colony formation ability of NBL cells were analyzed by MTT and colony formation assay. Flow cytometry assay was executed to measure the apoptosis and cell cycle. Dual-luciferase reporter assay was used to detect the targeted relationships among LINC01410, miR-506-3p, and WEE1. Additionally, the role of LINC01410 on NBL in vivo was evaluated according to a tumor xenograft model.

RESULTS

The expression of LINC01410 and WEE1 was enhanced and miR-506-3p was inhibited in NBL. LINC01410 knockdown attenuated the cell proliferation, colony formation ability, and inhibited tumor growth. Moreover, LINC01410 silencing facilitated the apoptosis and arrested the cell cycle. LINC01410 interacted with miR-506-3p to elevate the WEE1 expression in NBL. Additionally, miR-506-3p inhibition or WEE1 overexpression weakened the reduction effects of sh-LINC01410 on cell proliferation, colony formation ability, apoptosis, and cell cycle.

CONCLUSIONS

Knockdown of LINC01410 inhibited the development of NBL by miR-506-3p/WEE1 axis in vitro, which could serve as a potential therapeutic target for NBL therapy.

Long non-coding RNAs in ovarian cancer: expression profile and functional spectrum

Long non-coding RNAs (lncRNAs), initially recognized as byproducts of the transcription process, have been proven to play crucial modulatory roles in preserving overall homoeostasis of cells and tissues. Furthermore, aberrant levels of these transcripts have been shown to contribute many diseases, including cancer. Among these, many aspects of ovarian cancer biology have been found to be regulated by lncRNAs, including cancer initiation, progression and dissemination. In this review, we summarize recent studies to highlight the various roles of lncRNAs in ovary in normal and pathological conditions, immune system, diagnosis, prognosis, and therapy. We address lncRNAs that have been extensively studied in ovarian cancer and their contribution to cellular dynamics.

LncRNA DLX6-AS1 Promotes the Progression of Neuroblastoma by Activating STAT2 via Targeting miR-506-3p

Background

Neuroblastoma (NB) is a common malignant tumor of the sympathetic nervous system, mainly disturbing children. Long non-coding RNAs (lncRNAs) serving as promising cancer biomarkers have been well recognized. Our study intends to explore the functions of lncRNA X–inactive specific transcript (DLX6-AS1) in NB and provide a potential action mechanism.

Methods

The expression of DLX6-AS1, miR-506-3p and signal transducer and activator of transcription 2 (STAT2) was measured by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and colony formation assay. Cell cycle distribution was determined by flow cytometry assay. The protein level of cell cycle-related markers and STAT2 was detected by Western blot. Glycolysis progress was evaluated according to glucose consumption, lactate production and ATP level. The target genes were predicted by the online database Starbase3.0 and verified by dual-luciferase reporter assay.

Results

DLX6-AS1 expression was highly elevated in NB tissues and cells. DLX6-AS1 deficiency inhibited NB cell proliferation, cell cycle and glycolysis in vitro. MiR-506-3p was a target of DLX6-AS1, and miR-506-3p absence partly reversed the effects of DLX6-AS1 deficiency. Besides, STAT2 was targeted by miR-506-3p, and its expression was regulated by DLX6-AS1 through miR-506-3p. MiR-506-3p restoration also inhibited NB cell malignant behaviors, and STAT2 overexpression partially abolished the role of miR-506-3p restoration. Moreover, DLX6-AS1 deficiency weakened tumor growth in vivo.

Conclusion

DLX6-AS1 regulated cell proliferation, cell cycle and glycolysis in vitro and tumor growth in vivo to promote the development of NB by upregulating STAT2 via targeting miR-506-3p.

Contributions of HOX genes to cancer hallmarks: Enrichment pathway analysis and review

Homeobox genes function as master regulatory transcription factors during development, and their expression is often altered in cancer. The HOX gene family was initially studied intensively to understand how the expression of each gene was involved in forming axial patterns and shaping the body plan during embryogenesis. More recent investigations have discovered that HOX genes can also play an important role in cancer. The literature has shown that the expression of HOX genes may be increased or decreased in different tumors and that these alterations may differ depending on the specific HOX gene involved and the type of cancer being investigated. New studies are also emerging, showing the critical role of some members of the HOX gene family in tumor progression and variation in clinical response. However, there has been limited systematic evaluation of the various contributions of each member of the HOX gene family in the pathways that drive the common phenotypic changes (or "hallmarks") and that underlie the transformation of normal cells to cancer cells. In this review, we investigate the context of the engagement of HOX gene targets and their downstream pathways in the acquisition of competence of tumor cells to undergo malignant transformation and tumor progression. We also summarize published findings on the involvement of HOX genes in carcinogenesis and use bioinformatics methods to examine how their downstream targets and pathways are involved in each hallmark of the cancer phenotype.

Long non-coding RNA SNHG7 promotes neuroblastoma progression through sponging miR-323a-5p and miR-342-5p

Dysregulation of long non-coding RNAs (lncRNAs) has been known to be relevant to the progression of human cancers, including neuroblastoma (NB). Small nucleolar RNA host gene 7 (SNHG7) has been identified as an oncogene in a series of human cancers. The purpose of the present study was to investigate the function and underlying mechanism of SNHG7 in NB progression. qRT-PCR was used to determine the levels of SNHG7, cyclin D1 (CCND1), miR-323a-5p and miR-342-5p. Cell migration and invasion abilities were detected by transwell assays. Glucose consumption and lactate production were assessed using the corresponding assay kits. The targeted interaction between SNHG7 and miR-323a-5p or miR-342-5p was verified by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Xenograft tumor assays were performed to observe the effect of SNHG7 silencing on tumor growth in vivo. We found that SNHG7 was upregulated in NB tissues and cell lines, and high SNHG7 level was relevant to poor prognosis of NB patients. SNHG7 silencing resulted in the repression of NB cell migration, invasion and glycolysis. SNHG7 directly targeted miR-323a-5p and miR-342-5p and negatively modulated their expression in NB cells. The overexpression of miR-323a-5p or miR-342-5p weakened NB cell migration, invasion and glycolysis. Moreover, miR-323a-5p or miR-342-5p mediated the suppressive effect of SNHG7 silencing on NB cell progression. CCND1 was a direct target of miR-323a-5p and miR-342-5p. Additionally, SNHG7 knockdown repressed tumor growth in vivo. In conclusion, our study suggested that SNHG7 silencing hindered NB progression at least partly though sponging miR-323a-5p and miR-342-5p, illuminating its potential value as a therapeutic target.

Integrated analysis of lncRNA-mRNA networks associated with an SLA titanium surface reveals the potential role of HIF1A-AS1 in bone remodeling

Microstructured titanium surface implants, such as typical sandblasted and acid-etched (SLA) titanium implants, are widely used to promote bone apposition in prosthetic treatment by dental implants following tooth loss. Although there are multiple factors associated with the superior osseointegration of an SLA titanium surface, the molecular mechanisms of long noncoding RNAs (lncRNAs) are still unclear. In this study, we characterized smooth (SMO) and SLA surfaces, and compared the osteoinduction of these surfaces using human bone marrow-derived mesenchymal stem cells (hBMSCs) in vitro and implants in a rat model in vivo. Then, we used microarrays and bioinformatics analysis to investigate the differential expression profiles of mRNAs and lncRNAs on SMO and SLA titanium surfaces. An lncRNA–mRNA network was constructed, which showed an interaction between lncRNA HIF1A antisense RNA 1 (HIF1A-AS1) and vascular endothelial growth factor. We further found that knockdown of HIF1A-AS1 significantly decreased osteogenic differentiation of hBMSCs. This study screened SLA-induced lncRNAs using a systemic strategy and showed that lncRNA HIF1A-AS1 plays a role in promotion of new bone formation in the peri-implant area, providing a novel insight for future surface modifications of implants.

Long non-coding RNA HIF1A-AS1 plays a role in SLA titanium surface-induced osteogenic differentiation of hBMSCs by regulating p38 MAPK.

Bioinformatics analysis of prognosis-related long non-coding RNAs in invasive breast carcinoma

Breast cancer is one of the most common types of cancer among women worldwide and needs more sensitive prognostic biomarkers to improve its treatment. In the present study, differentially expressed long non-coding RNAs (lncRNAs) in invasive breast carcinoma from The Cancer Genome Atlas and cBioPortal database were investigated, identifying 292 differentially expressed lncRNAs in 1,100 cases. By analyzing the overall survival rate, 10 lncRNAs were significantly correlated with poor prognosis. To explore the underlying molecular mechanisms of the 10 prognosis-related lncRNAs, bioinformatic methods were used to predict the potential target miRNAs, mRNAs and proteins, and to construct a lncRNA-miRNA-mRNA regulatory network and lncRNA-protein interaction network. Finally, the functions of the target genes and proteins were insvestigated using Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses. The results showed that these 10 lncRNAs could be novel prognostic markers for invasive breast carcinoma and the present study aimed to provide novel insight into the diagnosis and treatment of breast cancer.

Transcriptome Analysis of lncRNAs in Pheochromocytomas and Paragangliomas

CONTEXT

Pheochromocytomas and paragangliomas (PPGLs) are neuroendocrine tumors explained by germline or somatic mutations in about 70% of cases. Patients with SDHB mutations are at high risk of developing metastatic disease, yet no reliable tumor biomarkers are available to predict tumor aggressiveness.

OBJECTIVE

We aimed at identifying long noncoding RNAs (lncRNAs) specific for PPGL molecular groups and metastatic progression.

DESIGN AND METHODS

To analyze the expression of lncRNAs, we used a mining approach of transcriptome data from a well-characterized series of 187 tumor tissues. Clustering consensus analysis was performed to determine a lncRNA-based classification, and informative transcripts were validated in an independent series of 51 PPGLs. The expression of metastasis-related lncRNAs was confirmed by RT-qPCR. Receiver operating characteristic (ROC) curve analysis was used to estimate the predictive accuracy of potential markers.

MAIN OUTCOME MEASURE

Univariate/multivariate and metastasis-free survival (MFS) analyses were carried out for the assessment of risk factors and clinical outcomes.

RESULTS

Four lncRNA-based subtypes strongly correlated with mRNA expression clusters (chi-square P-values from 1.38 × 10-32 to 1.07 × 10-67). We identified one putative lncRNA (GenBank: BC063866) that accurately discriminates metastatic from benign tumors in patients with SDHx mutations (area under the curve 0.95; P = 4.59 × 10-05). Moreover, this transcript appeared as an independent risk factor associated with poor clinical outcome of SDHx carriers (log-rank test P = 2.29 × 10-05).

CONCLUSION

Our findings extend the spectrum of transcriptional dysregulations in PPGL to lncRNAs and provide a novel biomarker that could be useful to identify potentially metastatic tumors in patients carrying SDHx mutations.

PABPC1-induced stabilization of BDNF-AS inhibits malignant progression of glioblastoma cells through STAU1-mediated decay

Glioblastoma is the most common and malignant form of primary central nervous tumor in adults. Long noncoding RNAs (lncRNAs) have been reported to play a pivotal role in modulating gene expression and regulating human tumor’s malignant behaviors. In this study, we confirmed that lncRNA brain-derived neurotrophic factor antisense (BDNF-AS) was downregulated in glioblastoma tissues and cells, interacted and stabilized by polyadenylate-binding protein cytoplasmic 1 (PABPC1). Overexpression of BDNF-AS inhibited the proliferation, migration, and invasion, as well as induced the apoptosis of glioblastoma cells. In the in vivo study, PABPC1 overexpression combined with BDNF-AS overexpression produced the smallest tumor and the longest survival. Moreover, BDNF-AS could elicit retina and anterior neural fold homeobox 2 (RAX2) mRNA decay through STAU1-mediated decay (SMD), and thereby regulated the malignant behaviors glioblastoma cells. Knockdown of RAX2 produced tumor-suppressive function in glioblastoma cells and increased the expression of discs large homolog 5 (DLG5), leading to the activation of the Hippo pathway. In general, this study elucidated that the PABPC1-BDNF-AS-RAX2-DLG5 mechanism may contribute to the anticancer potential of glioma cells and may provide potential therapeutic targets for human glioma.

Identification of plasma exosomes long non-coding RNA HAGLR and circulating tumor cells as potential prognosis biomarkers in non-small cell lung cancer

Background

The main purpose of this study was to identify the correlation between the expression of long non-coding RNA (lncRNA) HAGLR in plasma exosomes and the detection rate of circulating tumor cells (CTCs) in patients with non-small cell lung cancer (NSCLC).

Methods

LncRNA HAGLR expression was detected in plasma exosomes of 40 patients with NSCLC and 8 healthy subjects using qRT-PCR. CTCs were enriched and separated using CTC-BIOPSY^® abnormal cell separator. The correlations between lncRNA HAGLR expression in plasma exosomes and CTCs of patients with NSCLC and clinical pathological parameters were also analyzed. Bioinformatics analyses indicated HAGLR was evidently down-regulated in NSCLC tissues when compared to normal controls. The relationship between differential expression of HAGLR with different stages of NSCLC and clinical prognosis were elucidated using corresponding statistical methods.

Results

HAGLR was significantly decreased in NSCLC, and there was obvious correlation with overall survival (P<0.05). CTCs were detected in peripheral blood of patients with NSCLC with the positive rate of 70.0%. In lung squamous cell carcinoma (LUSC), compared with the high expression group of HAGLR, the low expression group had a better overall survival (P<0.05). At the same time, the high expression of HAGLR was positively correlated with the high detection rate of CTCs (P<0.05), suggesting that the disease may have a later tumor stage, and poor prognosis.

Conclusions

lncRNA HAGLR and CTCs could be used as potential biomarkers for NSCLC metastasis risk prediction.

HOXD-AS1 confers cisplatin resistance in gastric cancer through epigenetically silencing PDCD4 via recruiting EZH2

Increasing evidence suggests that dysregulation of long non-coding RNAs (lncRNAs) is implicated in chemoresistance in cancers. However, the function and molecular mechanisms of lncRNAs in gastric cancer chemoresistance are still not well understood. In this study, we aimed to investigate the functional role and the underlying molecular mechanisms of lncRNA HOXD cluster antisense RNA 1 (HOXD-AS1) in cisplatin (DDP) resistance in gastric cancer. Our results revealed that HOXD-AS1 was upregulated in DDP-resistant gastric cancer tissues and cells. Patients with gastric cancer with high HOXD-AS1 expression levels had a poor prognosis. Knockdown of HOXD-AS1 facilitated the sensitivity of DDP-resistant gastric cancer cells to DDP. Additionally, HOXD-AS1 epigenetically silenced PDCD4 through binding to the histone methyltransferase enhancer of zeste homologue 2 (EZH2) on the promoter of PDCD4, thus increasing H3K27me3. More importantly, PDCD4 silencing counteracted HOXD-AS1 knockdown-mediated enhancement of DDP sensitivity in DDP-resistant gastric cancer cells. In summary, HOXD-AS1 led to DDP resistance in gastric cancer by epigenetically suppressing PDCD4 expression, providing a novel therapeutic strategy for patients with gastric cancer with chemoresistance.

A prognostic 10-lncRNA expression signature for predicting the risk of tumour recurrence in breast cancer patients

Breast cancer is one of the most frequently diagnosed malignancies and a leading cause of cancer death among females. Multiple molecular alterations are observed in breast cancer. LncRNA transcripts were proved to play important roles in the biology of tumorigenesis. In this study, we aimed to identify lncRNA expression signature that can predict breast cancer patient survival. We developed a 10‐lncRNA signature‐based risk score which was used to separate patients into high‐risk and low‐risk groups. Patients in the low‐risk group had significantly better survival than those in the high‐risk group. Receiver operating characteristic analysis indicated that this signature exhibited excellent diagnostic efficiency for 1‐, 3‐ and 5‐year disease‐relapse events. Moreover, multivariate Cox regression analysis demonstrated that this 10‐lncRNA signature was an independent risk factor when adjusting for several clinical signatures such as age, tumour size and lymph node status. The prognostic value of risk scores was validated in the validation set. In addition, a nomogram was established and the calibration plots analysis indicated the good performance and clinical utility of the nomogram. In conclusion, our results demonstrated that this 10‐lncRNA signature effectively grouped patients at low and high risk of disease recurrence.

LncRNA XIST facilitates cell growth, migration and invasion via modulating H3 histone methylation of DKK1 in neuroblastoma

Long non-coding RNAs (lncRNAs) have been confirmed to be aberrantly expressed and involved in the progression of neuroblastoma. This study aimed to explore the expression profile of lncRNA X-inactive specific transcript (XIST) and its functional involvement in neuroblastoma. In this study, the relative level of XIST in neuroblastoma tissues and cell lines was detected by qPCR, and DKK1 protein expression was determined using western blot. The effect of XIST on cell growth, invasion and migration in vitro and in tumorigenesis of neuroblastoma was assessed. The level of H3K27me3 in DKK1 promoter was analyzed with ChIP-qPCR. Interaction between XIST and EZH2 was verified by RNA immunoprecipitation (RIP) and RNA pull-down assay. XIST was significantly upregulated in neuroblastoma tissues (n = 30) and cells lines, and it was statistically associated with the age and International Neuroblastoma Staging System (INSS) staging in neuroblastoma patients. Downregulation of XIST suppressed the growth, migration and invasion of neuroblastoma cells. EZH2 inhibited DKK1 expression through inducing H3 histone methylation in its promoter. XIST increased the level of H3K27me3 in DKK1 promoter via interacting with EZH2. Downregulation of XIST increased DKK1 expression to suppress neuroblastoma cell growth, invasion, and migration, which markedly restrained the tumor progression. In conclusion, XIST downregulated DKK1 by inducing H3 histone methylation via EZH2, thereby facilitating the growth, migration and invasion of neuroblastoma cells and retarding tumor progression.

LncRNA GClnc1 promotes proliferation and invasion of bladder cancer through activation of MYC

Various studies demonstrate that long noncoding RNAs (lncRNAs) act as oncogenes or tumor suppressors in cancer. However, the function of lncRNAs in bladder cancer still remains largely unknown. In this study, we identified an lncRNA, gastric cancer-associated lncRNA1 (GClnc1), which was in high abundance in bladder cancer tissues and its expression was related to poor survival rates in patients with bladder cancer. In vitro and in vivo assays showed that GClnc1 significantly promoted cell proliferation, metastasis, and invasiveness in bladder cancer. Mechanistically, we first found that GClnc1 bound to LIN28B and promoted the expression of myelocytomatosis proto-oncogene (MYC) through the LIN28B/let-7a/MYC pathway. In short, GClnc1 is clinically, functionally, and mechanistically oncogenic in bladder cancer. GClnc1 may be a potential target for treating patients with bladder cancer.-Zhuang, C., Ma, Q., Zhuang, C., Ye, J., Zhang, F., Gui, Y. LncRNA GClnc1 promotes proliferation and invasion of bladder cancer through activation of MYC.

Silencing of long noncoding RNA HOXD-AS1 inhibits proliferation, cell cycle progression, migration and invasion of hepatocellular carcinoma cells through MEK/ERK pathway

Accumulating findings reveal that long noncoding RNAs (lncRNAs) as crucial regulatory molecules serve vital functions in the progression of hepatocellular carcinoma (HCC). This study aims to investigate the biological roles and mechanisms of lncRNA HOXD cluster antisense RNA 1 (HOXD-AS1) in HCC cells based on transcriptome analysis. The Cancer Genome Atlas data analysis and experimental validation showed that HOXD-AS1 was increased in HCC tissues/cell lines and positively relevant to histologic grade. The subcellular localization results indicated HOXD-AS1 was dispersed both in the nucleus as well as the cytoplasm of HCC cells. In vitro loss-of-function experiments revealed that silencing of HOXD-AS1 could dramatically suppress the proliferation, migration, and invasion, and induce S or/and G2/M phase cell cycle arrest as well as apoptosis of Bel-7402 and MHCC97H cells accompanying the changes in expression levels of cyclin B1, cyclin D1, BCL-2, BAX, and MMP2. In vivo assay also showed that HOXD-AS1 silencing could markedly reduce xenograft tumor volume and weight of HCC cells. Transcriptome and bioinformatic analysis indicated that a total of 1103 genes were significantly altered by HOXD-AS1 silencing, of which 132 genes exhibited a significant correlation with HOXD-AS1 expression in HCC tissues. Gene Ontology (GO) enrichment analysis revealed differentially expressed genes were remarkably enriched in several cancer-related biological processes (cell proliferation, cell cycle, apoptosis, migration, angiogenesis, and hypoxic response). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis indicated that HOXD-AS1 has the potential to affect p53, tumor necrosis factor (TNF), mitogen-activated protein kinase (MAPK) pathway, and Western blot results further validated that HOXD-AS1 silencing could inhibit the MEK/ERK pathway in Bel-7402 cells. Collectively, HOXD-AS1, as an oncogenic lncRNA, might exert crucial functions in HCC progression and serve as a potential diagnostic biomarker and therapeutic target for HCC.

lncRNA SNHG16 is associated with proliferation and poor prognosis of pediatric neuroblastoma

Neuroblastoma (NB) is one of the most common extracranial solid tumors in children, which has complex molecular mechanisms. Increasing evidence has suggested that long noncoding RNAs (lncRNAs) account for NB pathogenesis. However, the function of small nucleolar RNA host gene 16 (SNHG16) in NB is currently unclear. In the present study, publically available data and clinical specimens were employed to verify the expression of SNHG16 in NB. Colony formation, real‑time cell proliferation and migration assays were performed to demonstrate the status of cellular proliferation and migration. Flow cytometry was used to examine cell cycle progression in SH‑SY5Y cells, and acridine orange/ethidium bromide staining and caspase‑3/7 activity measurements were applied to study cell apoptosis. To explore the underlying mechanism of SNHG16 function, an online database was used to identify potential RNA‑binding proteins that bind SNHG16. The expression of SNHG16 was revealed to be in line with the clinical staging of NB, and high SNHG16 expression was positively associated with poor clinical outcome. Furthermore, SNHG16 silencing inhibited cell proliferation, repressed migration, and induced cell cycle arrest at the G0/G1 phase in SH‑SY5Y cells. Additionally, apoptosis was undetectable in SH‑SY5Y cells following SNHG16 silencing. Bioinformatics analysis revealed that SNHG16 regulated cell proliferation in NB through transcriptional and translational pathways. These results suggested that SNHG16 may serve important roles in the development and progression of NB, and could represent a potential target for NB therapy.

Nuclear lncRNA HOXD-AS1 suppresses colorectal carcinoma growth and metastasis via inhibiting HOXD3-induced integrin β3 transcriptional activating and MAPK/AKT signalling

Background

Long noncoding RNAs (lncRNAs) have been indicated to play critical roles in cancer development and progression. LncRNA HOXD cluster antisense RNA1 (HOXD-AS1) has recently been found to be dysregulated in several cancers. However, the expression levels, cellular localization, precise function and mechanism of HOXD-AS1 in colorectal carcinoma (CRC) are largely unknown.

Methods

Real-time PCR and in situ hybridization were used to detect the expression of HOXD-AS1 in CRC tissue samples and cell lines. Gain- and loss-of-function experiments were performed to investigate the biological roles of HOXD-AS1 in CRC cell line. RNA pull down, RNA immunoprecipitation and chromatin immunoprecipitation assays were conducted to investigate the mechanisms underlying the functions of HOXD-AS1 in CRC.

Results

We observed that HOXD-AS1 was located in the nucleus of CRC cells and that nuclear HOXD-AS1 was downregulated in most CRC specimens and cell lines. Lower levels of nuclear HOXD-AS1 expression were associated with poor outcomes of CRC patients. HOXD-AS1 downregulation enhanced proliferation and migration of CRC cells in vitro and facilitated CRC tumourigenesis and metastasis in vivo. Mechanistic investigations revealed that HOXD-AS1 could suppress HOXD3 transcription by recruiting PRC2 to induce the accumulation of the repressive marker H3K27me3 at the HOXD3 promoter. Subsequently, HOXD3, as a transcriptional activator, promoted Integrin β3 transcription, thereby activating the MAPK/AKT signalling pathways.

Conclusion

Our results reveal a previously unrecognized HOXD-AS1-HOXD3-Integrin β3 regulatory axis involving in epigenetic and transcriptional regulation constitutes to CRC carcinogenesis and progression.

Electronic supplementary material

The online version of this article (10.1186/s12943-019-0955-9) contains supplementary material, which is available to authorized users.

Comprehensive analysis of long noncoding RNA expression in dorsal root ganglion reveals cell-type specificity and dysregulation after nerve injury

Dorsal root ganglion (DRG) neurons provide connectivity between peripheral tissues and the spinal cord. Transcriptional plasticity within DRG sensory neurons after peripheral nerve injury contributes to nerve repair but also leads to maladaptive plasticity, including the development of neuropathic pain. This study presents tissue and neuron-specific expression profiling of both known and novel long noncoding RNAs (LncRNAs) in the rodent DRG after nerve injury. We have identified a large number of novel LncRNAs expressed within the rodent DRG, a minority of which were syntenically conserved between the mouse, rat, and human, and including, both intergenic and antisense LncRNAs. We have also identified neuron type-specific LncRNAs in the mouse DRG and LncRNAs that are expressed in human IPS cell-derived sensory neurons. We show significant plasticity in LncRNA expression after nerve injury, which in mice is strain and gender dependent. This resource is publicly available and will aid future studies of DRG neuron identity and the transcriptional landscape in both the naive and injured DRG. We present our work regarding novel antisense and intergenic LncRNAs as an online searchable database, accessible from PainNetworks (http://www.painnetworks.org/). We have also integrated all annotated gene expression data in PainNetworks, so they can be examined in the context of their protein interactions.

Decoding epigenetic cell signaling in neuronal differentiation

Neurogenesis is the process by which new neurons are generated in the brain. Neural stem cells (NSCs) are differentiated into neurons, which are integrated into the neural network. Nowadays, pluripotent stem cells, multipotent stem cells, and induced pluripotent stem cells can be artificially differentiated into neurons utilizing several techniques. Specific transcriptional profiles from NSCs during differentiation are frequently used to approach and observe phenotype alteration and functional determination of neurons. In this context, the role of non-coding RNA, transcription factors and epigenetic changes in neuronal development and differentiation has gained importance. Epigenetic elucidation has become a field of intense research due to distinct patterns of normal conditions and different neurodegenerative disorders, which can be explored to develop new diagnostic methods or gene therapies. In this review, we discuss the complexity of transcription factors, non-coding RNAs, and extracellular vesicles that are responsible for guiding and coordinating neural development.

Long noncoding RNA HOXD-AS1 in various cancers: a meta-analysis and TCGA data review

Background and aims: HOXD antisense growth-associated long noncoding RNA (HOXD-AS1) was reported to be upregulated in various cancers, such as gastric cancer, hepatocellular carcinoma, colorectal cancer, and glioma. Here, we conducted a meta-analysis and The Cancer Genome Atlas data review to investigate the clinicopathologic and prognostic value of HOXD-AS1 in patients with malignant tumors.

Materials and methods: Systematic literatures were searched from PubMed, Medline, Cochrane Library, Web of Science, EMBASE database, Ovid, Chinese CNKI, and the Chinese WanFang database. The role of HOXD-AS1 in cancers was evaluated by pooled ORs and HRs with 95% CIs. The Cancer Genome Atlas dataset was used to explore the prognostic value of HOXD-AS1 in various cancers.

Global identification and characterization of lncRNAs that control inflammation in malignant cholangiocytes

BACKGROUND

Long noncoding RNAs (lncRNAs) are known to play important roles in different cell contexts, including cancers. However, little is known about lncRNAs in cholangiocarcinoma (CCA), a cholangiocyte malignancy with poor prognosis, and associated with chronic inflammation and damage to the biliary epithelium. This study determined whether lncRNAs were dysregulated and participated in disease diagnosis or pivotal inflammation pathways through a genome-wide lncRNA screening and functional analysis.

RESULTS

We firstly identified a large number of lncRNAs abnormally expressed between 9 pairs of cancerous and adjacent tissues of CCA, and between intra-hepatic CCA and extra-hepatic CCA through a genome-wide profiling. A set of aberrant differentially expressed lncRNAs were further validated in a training set (16 pairs) and a test set (11 pairs) of CCA patient samples. Following assessment of the diagnostic value of the 7 differentially expressed lncRNAs, we confirmed the optimal combination of H19, C3P1, AC005550.3, PVT1, and LPAL2 with area under the curve of 0.8828 [95% CI: 0.7441-1.021, P < 0.001], with 93.75% sensitivity and 81.25% specificity, at the cutoff point of - 0.2884 to distinguish the CCA tissue from the normal ones, suggesting that specific lncRNAs may have potential for detecting CCA. More importantly, the genome-wide locus and lncRNA/mRNA co-expression analyses revealed a set of lncRNAs that participated in inflammation and oxidative stress response pathways by regulating genes in cis or in trans. Finally, APOC1P1, PVT1, and LPAL2 were validated to regulate the migration and some pivotal inflammation genes under the CCA pathogenesis.

CONCLUSIONS

Our findings are the first to show that lncRNAs may not only be potential biomarkers of CCA progression but also respond to inflammation in CCA.

The clinical spectrum of CASQ1-related myopathy

OBJECTIVE

To identify and characterize patients with calsequestrin 1 (CASQ1)-related myopathy.

METHODS

Patients selected according to histopathologic features underwent CASQ1 genetic screening. CASQ1-mutated patients were clinically evaluated and underwent muscle MRI. Vacuole morphology and vacuolated fiber type were characterized.

RESULTS

Twenty-two CASQ1-mutated patients (12 families) were identified, 21 sharing the previously described founder mutation (p.Asp244Gly) and 1 with the p.Gly103Asp mutation. Patients usually presented in the sixth decade with exercise intolerance and myalgias and later developed mild to moderate, slowly progressive proximal weakness with quadriceps atrophy and scapular winging. Muscle MRI (n = 11) showed a recurrent fibrofatty substitution pattern. Three patients presented subclinical cardiac abnormalities. Muscle histopathology in patients with p.Asp244Gly showed vacuoles in type II fibers appearing empty in hematoxylin-eosin, Gomori, and nicotinamide adenine dinucleotide (NADH) tetrazolium reductase stains but strongly positive for sarcoplasmic reticulum proteins. The muscle histopathology of p.Gly103Asp mutation was different, showing also NADH-positive accumulation consistent with tubular aggregates.

CONCLUSIONS

We report the clinical and molecular details of the largest cohort of CASQ1-mutated patients. A possible heart involvement is presented, further expanding the phenotype of the disease. One mutation is common due to a founder effect, but other mutations are possible. Because of a paucity of symptoms, it is likely that CASQ1 mutations may remain undiagnosed if a muscle biopsy is not performed.

Integrated analysis of long non-coding RNAs and mRNAs associated with peritendinous fibrosis

The dysregulation of long non-coding RNAs (lncRNAs) is associated with the development of various diseases. However, little is known about the regulatory function of lncRNAs in peritendinous fibrosis. Therefore, the expression profiles of lncRNAs and mRNAs in normal tendon and fibrotic peritendinous tissues were analyzed in this study using RNA sequencing. In total, 219 lncRNAs and 3403 mRNAs were identified that were differentially expressed between the two sets of tissues. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed that the dysregulated mRNAs were mainly associated with immune regulation, inflammation, extracellular matrix (ECM) production and remodeling, and cell cycle regulation. An lncRNA-mRNA co-expression network revealed 181 network pairs comprising eight dysregulated lncRNAs and 146 mRNAs. The results of the bioinformatics analysis indicated that the dysregulated lncRNAs play a role in fibrogenesis through regulation of the cell cycle, inflammation, and ECM production. Furthermore, silencing the lncRNA dnm3os prevented transforming growth factor (TGF)-β1-induced tenocyte proliferation and expression of genes related to fibrogenesis. These findings provide a basis for investigations into the regulatory mechanisms underlying the development and progression of peritendinous fibrosis.

Pathological bases and clinical impact of long noncoding RNAs in prostate cancer: a new budding star

Long non-coding RNAs (lncRNAs) are functional RNAs longer than 200 nucleotides. Recent advances in the non-protein coding part of human genome analysis have discovered extensive transcription of large RNA transcripts that lack coding protein function, termed non-coding RNA (ncRNA). It is becoming evident that lncRNAs may be an important class of pervasive genes involved in carcinogenesis and metastasis. However, the biological and molecular mechanisms of lncRNAs in diverse diseases are not yet fully understood. Thus, it is anticipated that more efforts should be made to clarify the lncRNA world. Moreover, accumulating evidence has demonstrated that many lncRNAs are dysregulated in prostate cancer (PC) and closely related to tumorigenesis, metastasis, and prognosis or diagnosis. In this review, we will briefly outline the regulation and functional role of lncRNAs in PC. Finally, we discussed the potential of lncRNAs as prospective novel targets in PC treatment and biomarkers for PC diagnosis.

Long noncoding RNA HOXD-AS1 aggravates osteosarcoma carcinogenesis through epigenetically inhibiting p57 via EZH2

Osteosarcoma is the most common primary malignant bone tumor and long non-coding RNAs (lncRNAs) have been proved to epigenetically regulate the oncogenesis of osteosarcoma. In this research, we investigate the role of lncRNA HOXD-AS1 on the osteosarcoma oncogenesis. Results revealed that HOXD-AS1 expression level was significantly up-regulated in osteosarcoma tissue and cells, moreover, the aberrant overexpression predicted the poor prognosis of osteosarcoma patients. Loss-of-functional experiments indicated that HOXD-AS1 silencing inhibited the osteosarcoma cells proliferation and induced G1/G0 phase arrest in vitro, and repressed tumor cell growth in vivo. Mechanistic investigations showed that HOXD-AS1 epigenetically repressed p57 through recruiting enhancer of zeste homolog 2 (EZH2) to the promoter of p57. Rescue experiments revealed that p57 could recover the oncogenic role of HOXD-AS1 on osteosarcoma. In conclusion, our study confirmed that HOXD-AS1 could interact with EZH2, and then repress p57 expression, to aggravate osteosarcoma oncogenesis. which provide new idea for the osteosarcoma tumorigenesis.

Comprehensive identification of long noncoding RNAs in colorectal cancer

Colorectal cancer (CRC) is one of the most common cancers in humans and a leading cause of cancer-related deaths worldwide. As in the case of other cancers, CRC heterogeneity leads to a wide range of clinical outcomes and complicates therapy. Over the years, multiple factors have emerged as markers of CRC heterogeneity, improving tumor classification and selection of therapeutic strategies. Understanding the molecular mechanisms underlying this heterogeneity remains a major challenge. A considerable research effort is therefore devoted to identifying additional features of colorectal tumors, in order to better understand CRC etiology and to multiply therapeutic avenues. Recently, long noncoding RNAs (lncRNAs) have emerged as important players in physiological and pathological processes, including CRC. Here we looked for lncRNAs that might contribute to the various colorectal tumor phenotypes. We thus monitored the expression of 4898 lncRNA genes across 566 CRC samples and identified 282 lncRNAs reflecting CRC heterogeneity. We then inferred potential functions of these lncRNAs. Our results highlight lncRNAs that may participate in the major processes altered in distinct CRC cases, such as WNT/β-catenin and TGF-β signaling, immunity, the epithelial-to-mesenchymal transition (EMT), and angiogenesis. For several candidates, we provide experimental evidence supporting our functional predictions that they may be involved in the cell cycle or the EMT. Overall, our work identifies lncRNAs associated with key CRC characteristics and provides insights into their respective functions. Our findings constitute a further step towards understanding the contribution of lncRNAs to CRC heterogeneity. They may open new therapeutic opportunities.

Angio-LncRs: LncRNAs that regulate angiogenesis and vascular disease

Long noncoding RNAs (lncRNAs) represent a large subgroup of RNAs that are longer than 200 nucleotides and have no apparent protein coding potential. They have diverse functions in different biological processes by regulating chromatin remodeling or protein translation. This review summarizes the recent progress of lncRNAs in angiogenesis and vascular diseases. A general overview of lncRNA functional mechanisms will be introduced. A list of lncRNAs, which are termed "Angio-LncRs", including MALAT1, MANTIS, PUNISHER, MEG3, MIAT, SENCR and GATA6-AS, will be discussed regarding their expression, regulation, function and mechanism of action in angiogenesis. Implications of lncRNAs in vascular diseases, such as atherosclerosis, hypertension, vascular retinopathies and tumor angiogenesis will also be discussed.

HOXD-AS1/miR-130a sponge regulates glioma development by targeting E2F8

Glioma development is an extremely complex process with changes occurring in numerous genes. HOXD antisense growth-associated long noncoding RNA (HOXD-AS1), an important long noncoding RNA (lncRNA), is known to regulate metastasis-related gene expression in bladder cancer, ovarian cancer and neuroblastoma. Here, we elucidated the function and possible molecular mechanisms of lncRNA HOXD-AS1 in human glioma cells. Our results proved that HOXD-AS1 expression was upregulated in glioma tissues and in glioma cell lines. HOXD-AS1 overexpression promoted cell migration and invasion in vitro, whereas knockdown of HOXD-AS1 expression repressed these cellular processes. Mechanistic studies further revealed that HOXD-AS1 could compete with the transcription factor E2F8 to bind with miR-130a, thus affecting E2F8 expression. Additionally, reciprocal repression was observed between HOXD-AS1 and miR-130a, and miR-130a mediated the tumor-suppressive effects of HOXD-AS1 knockdown. Taken together, these results provide a comprehensive analysis of the role of HOXD-AS1 in glioma cells and offer important clues to understand the key roles of competing endogenous RNA (ceRNA) mechanisms in human glioma.

Long non-coding RNA SNHG15 interacts with and stabilizes transcription factor Slug and promotes colon cancer progression

Slug is a fast-turnover transcription factor critical for controlling cell fate and cancer cell invasion and metastasis. The stability of Slug is important and maintained by diverse mechanisms. In this study, we presented a paradigm of this activity by identifying long noncoding RNA (lncRNA) small nucleolar RNA host gene 15 (SNHG15) that binds to and stabilizes Slug in colon cancer cells. LncRNA SNHG15 transcription is upregulated in a variety of human cancers according to The Cancer Genome Atlas. Here, ectopic expression of SNHG15 promoted colon cancer cell migration in vitro, accelerated xenografted tumor growth in vivo, and elevated levels of SNHG15 were associated with poor prognosis for colon cancer patients. Mechanistically, SNHG15 maintains Slug stability in living cells by impeding its ubiquitination and degradation through interaction with the zinc finger domain of Slug. These findings revealed a novel mechanism underlying the control of Slug stability by demonstrating that oncogenic lncRNA SNHG15 interacts with and blocks Slug degradation via the ubiquitin-proteasome system.

The Long (lncRNA) and Short (miRNA) of It: TGFβ-Mediated Control of RNA-Binding Proteins and Noncoding RNAs

RNA-binding proteins (RBP) and noncoding RNAs (ncRNA), such as long noncoding RNAs (lncRNA) and microRNAs (miRNA), control co- and posttranscriptional gene regulation (PTR). At the PTR level, RBPs and ncRNAs contribute to pre-mRNA processing, mRNA maturation, transport, localization, turnover, and translation. Deregulation of RBPs and ncRNAs promotes the onset of cancer progression and metastasis. Both RBPs and ncRNAs are altered by signaling cascades to cooperate or compete with each other to bind their nucleic acid targets. Most importantly, transforming growth factor-beta (TGFβ) signaling plays a significant role in controlling gene expression patterns by targeting RBPs and ncRNAs. Because of TGFβ signaling in cancer, RBP-RNA or RNA-RNA interactions are altered and cause enhanced cell growth and tumor cell dissemination. This review focuses on the emerging concepts of TGFβ signaling on posttranscriptional gene regulation and highlights the implications of RBPs and ncRNAs in cancer progression and metastasis. Mol Cancer Res; 16(4); 567-79. ©2018 AACR.

The long non-coding RNA GAS5 differentially regulates cell cycle arrest and apoptosis through activation of BRCA1 and p53 in human neuroblastoma

The long non-coding RNA GAS5 has been shown to modulate cancer proliferation in numerous human cancer systems and has been correlated with successful patient outcome. Our examination of GAS5 in neuroblastoma has revealed robust expression in both MYCN-amplified and non-amplified cell lines. Knockdown of GAS5 In vitro resulted in defects in cell proliferation, apoptosis, and induced cell cycle arrest. Further analysis of GAS5 clones revealed multiple novel splice variants, two of which inversely modulated with MYCN status. Complementation studies of the variants post-knockdown of GAS5 indicated alternate phenotypes, with one variant (FL) considerably enhancing cell proliferation by rescuing cell cycle arrest and the other (C2) driving apoptosis, suggesting a unique role for each in neuroblastoma cancer physiology. Global sequencing and ELISA arrays revealed that the loss of GAS5 induced p53, BRCA1, and GADD45A, which appeared to modulate cell cycle arrest in concert. Complementation with only the FL GAS5 clone could rescue cell cycle arrest, stabilizing HDM2, and leading to the loss of p53. Together, these data offer novel therapeutic targets in the form of lncRNA splice variants for separate challenges against cancer growth and cell death.

Angiogenic patterning by STEEL, an endothelial-enriched long noncoding RNA

Endothelial cell (EC)-enriched protein coding genes, such as endothelial nitric oxide synthase (eNOS), define quintessential EC-specific physiologic functions. It is not clear whether long noncoding RNAs (lncRNAs) also define cardiovascular cell type-specific phenotypes, especially in the vascular endothelium. Here, we report the existence of a set of EC-enriched lncRNAs and define a role for spliced-transcript endothelial-enriched lncRNA (STEEL) in angiogenic potential, macrovascular/microvascular identity, and shear stress responsiveness. STEEL is expressed from the terminus of the HOXD locus and is transcribed antisense to HOXD transcription factors. STEEL RNA increases the number and integrity of de novo perfused microvessels in an in vivo model and augments angiogenesis in vitro. The STEEL RNA is polyadenylated, nuclear enriched, and has microvascular predominance. Functionally, STEEL regulates a number of genes in diverse ECs. Of interest, STEEL up-regulates both eNOS and the transcription factor Kruppel-like factor 2 (KLF2), and is subject to feedback inhibition by both eNOS and shear-augmented KLF2. Mechanistically, STEEL up-regulation of eNOS and KLF2 is transcriptionally mediated, in part, via interaction of chromatin-associated STEEL with the poly-ADP ribosylase, PARP1. For instance, STEEL recruits PARP1 to the KLF2 promoter. This work identifies a role for EC-enriched lncRNAs in the phenotypic adaptation of ECs to both body position and hemodynamic forces and establishes a newer role for lncRNAs in the transcriptional regulation of EC identity.

Knockdown of long non-coding RNA HOXD-AS1 inhibits the progression of osteosarcoma

Long non-coding RNA HOXD-AS1 (HOXD-AS1) has recently been shown to be involved in the development and progression of multiple cancers. However, the expression, significance, and biological function of HOXD-AS1 in osteosarcoma (OS) remain unknown. Here, we found that the expression level of HOXD-AS1 was significantly upregulated in OS tissues and cells. Furthermore, high expression of HOXD-AS1 was positively associated with the clinical and pathological characteristics of OS, including tumor stage and lymph node metastasis, and negatively correlated with overall survival rate. in vitro assays confirmed that knockdown of HOXD-AS1 suppressed cell proliferation, colony formation, migration, and invasion, and promoted cell cycle arrest at G1 stage and apoptosis in OS cells. in vivo assays confirmed that knockdown of HOXD-AS1 significantly decreased tumor growth in xenograft mice, and decreased tumor size and weight. Importantly, we also showed that knockdown of HOXD-AS1 significantly reduced signal transducer and activator of transcription 3 and its target protein (CyclinD1, Bcl-2, and MMP-2) expression in vitro and in vivo. Moreover, overexpression of STAT3 could reverse the suppression of proliferation ability induced by sh-HOXD-AS1 in U2OS cells. Collectively, our data indicated that HOXD-AS1 might be an oncogenic long non-coding RNA (lncRNA) and might be a potential attractive therapeutic target for OS.