The various and shared roles of lncRNAs during development

Long non-coding RNA CASC15 enhances learning and memory in mice by promoting synaptic plasticity in hippocampal neurons

Alzheimer's disease (AD) is a debilitating systemic disorder that has a detrimental impact on the overall well-being of individuals. Emerging research suggests that long non-coding RNAs play a role in neural development and function. Nevertheless, the precise relationship between lncRNAs and Alzheimer's disease remains uncertain. The authors' recent discoveries have uncovered an unconventional mechanism involving the regulation of synaptic plasticity and the functioning of the hippocampal fragile X mental retardation protein 1 (FMR1)-neurotrophin 3 (NTF3) pathway, which is mediated by cancer susceptibility candidate 15 (CASC15). Subsequently, functional rescue experiments were performed to illustrate the efficient delivery of exosomes harboring a significant amount of 2610307p16Rik transcripts, which is the murine equivalent of human CASC15, to the hippocampal region of mice. This resulted in significant improvements in synaptic morphological plasticity and cognitive function in APP/PS1 mice. Given the pivotal involvement of CASC15 in synaptic plasticity and the distinctive regulatory mechanisms of the CASC15-FMR1-NTF3 axis, CASC15 emerges as a promising biomarker for Alzheimer's disease and may even possess potential as a feasible therapeutic target.

Sex differences on constitutive long non-coding RNA expression: Modulatory effect of estradiol and testosterone in muscle cells

INTRODUCTION

Despite the growing awareness of sexual dimorphism between males and females under pathological and physiological conditions, sex bias in biomedical research in animal models and patients is still present nowadays. The main objective of this work was to investigate sex differences in constitutive long non-coding RNA expression in spinal cord and skeletal muscle from wild-type mice.

MATERIALS AND METHODS

To assess the influence of gender on long non-coding RNAs, we extracted RNA from tissues of male and female mice and analyzed the expression on nine long non-coding RNAs, selected for being among the most commonly studied or exerting an important role in muscle, at 50, 60, and 120 days of age.

RESULTS AND DISCUSSION

We observed age- and tissue-dependent significant sex differences, being more prominent in skeletal muscle. We also studied the effect of sex steroid hormones on long non-coding RNA expression in vitro, noticing a modulation of long non-coding RNA levels upon estradiol and dihydrotestosterone treatment in muscle.

CONCLUSIONS

Taken together, results obtained evidenced sex differences on constitutive long non-coding RNA expression and suggested an influence of steroid hormones complementary to other possible factors. These findings emphasize the importance of including both sexes in experimental design to minimize any potential sex bias.

Long non-coding RNA MEG3 knockdown represses airway smooth muscle cells proliferation and migration via sponging miR-143-3p/FGF9 in asthma

BACKGROUND

Asthma is a respiratory disease characterized by airway remodeling. We aimed to find out the role and mechanism of lncRNA MEG3 in asthma.

METHODS

We established a cellular model of asthma by inducing human airway smooth muscle cells (HASMCs) with PDGF-BB, and detected levels of lncRNA MEG3, miR-143-3p and FGF9 in HASMCs through qRT-PCR. The functions of lncRNA MEG3 or miR-143-3p on HASMCs were explored by cell transfection. The binding sites of miR-143-3p and FGF9 were subsequently analyzed with bioinformatics software, and validated with dual-luciferase reporter assay. MTT, 5-Ethynyl-2'-deoxyuridine (EdU) assay, and Transwell were used to detect the effects of lncRNA MEG3 or miR-143-3p on proliferation and migration of HASMCs. QRT-PCR and western blot assay were used to evaluate the level of proliferation-related marker PCNA in HASMCs.

RESULTS

The study found that lncRNA MEG3 negatively correlated with miR-143-3p, and miR-143-3p could directly target with FGF9. Silence of lncRNA MEG3 can suppress migration and proliferation of PDGF-BB-induced HASMCs via increasing miR-143-3p. Further mechanistic studies revealed that miR-143-3p negatively regulated FGF9 expression in HASMCs. MiR-143-3p could inhibit PDGF-BB-induced HASMCs migration and proliferation through downregulating FGF9.

CONCLUSION

LncRNA MEG3 silencing could inhibit the migration and proliferation of HASMCs through regulating miR-143-3p/FGF9 signaling axis. These results imply that lncRNA MEG3 plays a protective role against asthma.

lncRNA Biomarkers of Glioblastoma Multiforme

Long noncoding RNAs (lncRNAs) are RNA molecules of 200 nucleotides or more in length that are not translated into proteins. Their expression is tissue-specific, with the vast majority involved in the regulation of cellular processes and functions. Many human diseases, including cancer, have been shown to be associated with deregulated lncRNAs, rendering them potential therapeutic targets and biomarkers for differential diagnosis. The expression of lncRNAs in the nervous system varies in different cell types, implicated in mechanisms of neurons and glia, with effects on the development and functioning of the brain. Reports have also shown a link between changes in lncRNA molecules and the etiopathogenesis of brain neoplasia, including glioblastoma multiforme (GBM). GBM is an aggressive variant of brain cancer with an unfavourable prognosis and a median survival of 14-16 months. It is considered a brain-specific disease with the highly invasive malignant cells spreading throughout the neural tissue, impeding the complete resection, and leading to post-surgery recurrences, which are the prime cause of mortality. The early diagnosis of GBM could improve the treatment and extend survival, with the lncRNA profiling of biological fluids promising the detection of neoplastic changes at their initial stages and more effective therapeutic interventions. This review presents a systematic overview of GBM-associated deregulation of lncRNAs with a focus on lncRNA fingerprints in patients' blood.

LINC02086 inhibits ferroptosis and promotes malignant phenotypes of pancreatic cancer via miR-342-3p/CA9 axis

Long noncoding RNAs (lncRNAs) play important roles in modulating the tumorigenesis and progression of malignant tumors. LINC02086 is a newly identified oncogene associated with tumorigenesis, but its role in pancreatic cancer (PC) has not been fully elucidated. In this study we examined the expression levels of LINC02086, miR-342-3p, and CA9 in PC. The relationship of ferroptosis with these factors was analyzed by detecting the expression levels of Fe2+, reactive oxygen species (ROS), and ferroptosis marker proteins. The expression of these genes was altered to observe their effects on cell proliferation, migration, and invasion ability. Bioinformatics was used to predict target genes, and the binding relationship was verified luciferase reporter assay. Finally, the function of LINC02086 was evaluated in vivo. The findings suggest that LINC02086 is highly expressed in PC tissues and cell lines and is correlated with a poor prognosis. In vitro experiments demonstrated that LINC02086 knockdown promoted ferroptosis in PC cells to suppress their malignant phenotype. LINC02086 acts as a competitive endogenous RNA that adsorbed miR-342-3p. miR-342-3p hinders the malignant progression of PC by promoting ferroptosis. In addition, miR-342-3p targets CA9 and affects its function. Further mechanistic studies revealed that LINC02086 inhibits ferroptosis and promotes PC progression by acting as a sponge for miR-342-3p to upregulate CA9 expression. In vivo experiments further confirmed this mechanism. Taken together, LINC02086 upregulates CA9 expression by competitively binding with miR-342-3p, thereby inhibiting ferroptosis in PC cells and promoting their malignant phenotype. The results of our study provide new insights into how LINC02086 contributes to the progression of PC.

Molecular mechanism of lncRNAs in pathogenesis and diagnosis of auto-immune diseases, with a special focus on lncRNA-based therapeutic approaches

Autoimmune diseases are a diverse set of conditions defined by organ damage due to abnormal innate and acquired immune system responses. The pathophysiology of autoimmune disorders is exceedingly intricate and has yet to be fully understood. The study of long non-coding RNAs (lncRNAs), non-protein-coding RNAs with at least 200 nucleotides in length, has gained significant attention due to the completion of the human genome project and the advancement of high-throughput genomic approaches. Recent research has demonstrated how lncRNA alters disease development to different degrees. Although lncRNA research has made significant progress in cancer and generative disorders, autoimmune illnesses are a relatively new research area. Moreover, lncRNAs play crucial functions in differentiating various immune cells, and their potential relationships with autoimmune diseases have received growing attention. Because of the importance of Th17/Treg axis in auto-immune disease development, in this review, we discuss various molecular mechanisms by which lncRNAs regulate the differentiation of Th17/Treg cells. Also, we reviewed recent findings regarding the several approaches in the application of lncRNAs in the diagnosis and treatment of human autoimmune diseases, as well as current challenges in lncRNA-based therapeutic approaches to auto-immune diseases.

The expression and function of long noncoding RNAs in hepatocellular carcinoma

With the deepening of the genome project study, attention on noncoding RNAs is increasing. Long noncoding RNAs (lncRNAs) have become a new research hotspot. A growing number of studies have revealed that lncRNAs are involved in tumorigenesis and tumor suppressor pathways. Aberrant expressions of lncRNAs have been found in a variety of human tumors including hepatocellular carcinoma (HCC). In this review, we provide a brief introduction to lncRNA and highlight recent research on the functions and clinical significance of lncRNAs in HCC.

Expression Profiles of Long Non-Coding RNAs in the Articular Cartilage of Rats Exposed to T-2 Toxin

T-2 toxin could induce bone damage. But there is no specific mechanism about the long non-coding RNAs (lncRNAs) involved in T-2 toxin-induced articular cartilage injury. In this study, 24 SD rats were randomly divided into a control group and a T-2 group, which were administered 4% absolute ethanol and 100 ng/g · bw/day of T-2 toxin, respectively. After treatment for 4 weeks, safranin O/fast green staining identified the pathological changes in the articular cartilage of rats, and immunofluorescence verified the autophagy level increase in the T-2 group. Total RNA was isolated, and high-throughput sequencing was performed. A total of 620 differentially expressed lncRNAs (DE-lncRNAs) were identified, and 326 target genes were predicted. Enrichment analyses showed that the target genes of DE-lncRNAs were enriched in the autophagy-related biological processes and pathways. According to the autophagy database, a total of 23 autophagy-related genes were identified, and five hub genes (Foxo3, Foxo1, Stk11, Hdac4, and Rela) were screened using the Maximal Clique Centrality algorithm. The Human Protein Atlas database indicated that Rela and Hdac4 proteins were highly expressed in the bone marrow tissue, while Foxo3, Foxo1, and Stk11 proteins were reduced. According to Enrichr, etoposide and diatrizoic acid were identified as the key drugs. The real-time quantitative PCR results were consistent with the RNA sequencing (RNA-Seq) results. These results suggested that autophagy was involved in the rat articular cartilage lesions induced by T-2 toxin. The lncRNAs of NONRATG014223.2, NONRATG012484.2, NONRATG021591.2, NONRATG024691.2, and NONRATG002808.2, and their target genes of Foxo3, Foxo1, Stk11, Hdac4, and Rela, respectively, were the key regulator factors of autophagy.

Transcriptome analysis reveals mRNAs and long non-coding RNAs associated with fecundity in the hypothalamus of high-and low-fecundity goat

As an important organ that coordinates the neuroendocrine system, the hypothalamus synthesizes and secretes reproductive hormones that act on the goat organism, thereby precisely regulating follicular development and reproductive processes in goats. However, it is still elusive to explore the mechanism of hypothalamic effects on goat fertility alone. Therefore, RNA-seq was used to analyze the gene expression in hypothalamic tissues of goats in high fertility group (HFG: litter size per litter ≥2) and low fertility group (LFG: litter size per litter = 1), and identified the differential lncRNAs and mRNAs and their associated pathways related to their fertility. The results showed that a total of 23 lncRNAs and 57 mRNAs were differentially expressed in the hypothalamic tissue of high and low fertility goats. GO terms and KEGG functional annotation suggest that DE lncRNAs and DE mRNAs were significantly enriched in hormone-related pathways regulating ovarian development, hormone synthesis and secretion, regulation of reproductive processes, Estrogen signaling pathway, Oxytocin signaling pathway and GnRH signaling pathway. And we constructed a co-expression network of lncRNAs and target genes, and identified reproduction-related genes such as NMUR2, FEZF1, and WT1. The sequencing results of the hypothalamic transcriptome have broadened our understanding of lncRNA and mRNA in goat hypothalamic tissue and provided some new insights into the molecular mechanisms of follicle development and regulation of its fertility in goats.

Systematic Characterization and Regulatory Role of lncRNAs in Asian Honey Bees Responding to Microsporidian Infestation

Long noncoding RNAs (lncRNAs) are pivotal regulators in gene expression and diverse biological processes, such as immune defense and host-pathogen interactions. However, little is known about the roles of lncRNAs in the response of the Asian honey bee (Apis cerana) to microsporidian infestation. Based on our previously obtained high-quality transcriptome datasets from the midgut tissues of Apis cerana cerana workers at 7 days post inoculation (dpi) and 10 dpi with Nosema ceranae (AcT7 and AcT10 groups) and the corresponding un-inoculated midgut tissues (AcCK7 and AcCK10 groups), the transcriptome-wide identification and structural characterization of lncRNAs were conducted, and the differential expression pattern of lncRNAs was then analyzed, followed by investigation of the regulatory roles of differentially expressed lncRNAs (DElncRNAs) in host response. Here, 2365, 2322, 2487, and 1986 lncRNAs were, respectively, identified in the AcCK7, AcT7, AcCK7, and AcT10 groups. After removing redundant ones, a total of 3496 A. c. cerana lncRNAs were identified, which shared similar structural characteristics with those discovered in other animals and plants, such as shorter exons and introns than mRNAs. Additionally, 79 and 73 DElncRNAs were screened from the workers' midguts at 7 dpi and 10 dpi, respectively, indicating the alteration of the overall expression pattern of lncRNAs in host midguts after N. ceranae infestation. These DElncRNAs could, respectively, regulate 87 and 73 upstream and downstream genes, involving a suite of functional terms and pathways, such as metabolic process and Hippo signaling pathway. Additionally, 235 and 209 genes co-expressed with DElncRNAs were found to enrich in 29 and 27 terms, as well as 112 and 123 pathways, such as ABC transporters and the cAMP signaling pathway. Further, it was detected that 79 (73) DElncRNAs in the host midguts at 7 (10) dpi could target 321 (313) DEmiRNAs and further target 3631 (3130) DEmRNAs. TCONS_00024312 and XR_001765805.1 were potential precursors for ame-miR-315 and ame-miR-927, while TCONS_00006120 was the putative precursor for both ame-miR-87-1 and ame-miR-87-2. These results together suggested that DElncRNAs are likely to play regulatory roles in the host response to N. ceranae infestation through the regulation of neighboring genes via a cis-acting effect, modulation of co-expressed mRNAs via trans-acting effect, and control of downstream target genes' expression via competing endogenous RNA networks. Our findings provide a basis for disclosing the mechanism underlying DElncRNA-mediated host N. ceranae response and a new perspective into the interaction between A. c. cerana and N. ceranae.

The ferroptosis-related long non-coding RNAs signature predicts biochemical recurrence and immune cell infiltration in prostate cancer

BACKGROUND

Findings from numerous studies have revealed that ferroptosis is closely related to tumorigenesis and immune cell infiltration. Long non-coding RNAs (lncRNAs) are reportedly involved in the progression of various cancers, including prostate cancer (PCa). This study was designed to establish a ferroptosis-related lncRNA (frlncRNA) signature to predict PCa prognosis.

METHODS

The frlncRNAs were identified by studying their expression by Pearson's correlation analysis. Differentially expressed prognosis related frlncRNAs were identified by the Wilcoxon test and univariate Cox regression analysis. The LASSO Cox regression model was used to build a model to predict biochemical recurrence (BCR) based on frlncRNAs. The GSEA software (version 4.1.0) was used to explore the enriched pathways in high- and low- risk groups. Patients with PCa were clustered into different subgroups by unsupervised clustering based on the frlncRNAs considered in the prognostic model. Real-time PCR and CCK8 assays were performed to verify the expression and function of frlncRNAs.

RESULTS

We identified 35 differentially expressed prognosis related frlncRNAs based on data on PCa from TCGA. A risk signature based on five frlncRNAs (AP006284.1, AC132938.1, BCRP3, AL360181.4 and AL135999.1), was confirmed to perform well in predicting BCR. The high-risk group had higher disease grades and a greater number of infiltrating immune cells. Besides this, we found that the five frlncRNAs were connected with typical immune checkpoints. With respect to molecular mechanisms, several metabolic pathways were found to enriched in the low-risk group. Furthermore, patients could be classified into different subtypes with different PSA-free times using the five frlncRNAs. Notably, AP006284.1, AC132938.1, BCRP3 and AL135999.1 were upregulated in PCa cells and tissues, whereas AL360181.4 exhibited the opposite trend. The downregulation of BCRP3 and AP006284.1 impaired the proliferation of 22RV1 cells.

CONCLUSION

We generated a prognostic model based on five frlncRNAs, with clinical usefulness, and thus provided a novel strategy for predicting the BCR of patients with PCa.

LINC01234 regulates microRNA-27b-5p to induce the migration, invasion and self-renewal of ovarian cancer stem cells through targeting SIRT5

LINC01234 has been suggested to correlate with the survival of ovarian cancer (OS), but its role in the properties of OC stem cells (OCSCs) has been rarely described. We aim to investigate the effect of LINC01234 on the differentiation and self-renewal of OCSCs through adsorption of microRNA (miR)-27b-5p to target sirtuins 5 (SIRT5). Expression of LINC01234 and SIRT5 in OC and normal samples included in TCGA and GTEx was searched through the GEPIA2 database. Bioinformatics analysis was conducted to predict the relation of LINC01234, miR-27b-5p and SIRT5. Expression of LINC01234, miR-27b-5p and SIRT5 in OC tissues and cells was detected. OCSCs were cultured and identified. CD133⁺ OCSCs were introduced with related oligonucleotides or vectors of LINC01234 or miR-27b-5p and SIRT5 to figure out their roles in OCSCs progression and tumorigenesis in vivo. The interaction of miR-27b-5p with LINC01234 or SIRT5 was analyzed. Bioinformatics analysis suggested that LINC01234 was very likely to influence SIRT5 and regulate the development of OC through miR-27b-5p. Up-regulated LINC01234 exhibited in OC tissues and cells. Down-regulated LINC01234 or elevated miR-27b-5p suppressed OCSCs progression and tumorigenesis in vivo. LINC01234 could restore SIRT5 expression by binding to miR-27b-5p. Down-regulated miR-27b-5p reversed the effect of silenced LINC01234 on OCSCs development and tumorigenesis in vivo. Up-regulation of SIRT5 reduced the effects of elevated miR-27b-5p on OCSCs progression and tumorigenesis in vivo. LINC01234 regulates miR-27b-5p to induce the migration, invasion and self-renewal of OCSCs through targeting SIRT5.

lncRNA TUG1 protects intestinal epithelial cells from damage induced by high glucose and high fat via AMPK/SIRT1

he incidence of obesity and type 2 diabetes mellitus (T2DM) is increasing year by year and shows a trend towards younger age groups worldwide. It has become a disease that endangers the health of individuals all over the world. Among numerous weight loss surgeries, sleeve gastrectomy (SG) has become one of the most common surgical strategies for the treatment of T2DM. However, SG‑mediated alterations to the molecular mechanism of metabolism require further investigation. Thus, reverse transcription‑quantitative PCR was used to detect the expression levels of long non‑coding (lnc)RNA taurine‑upregulated gene 1 (TUG1), Sirtuin 1 (SIRT1), AMP‑activated protein kinase (AMPK) and uncoupling protein 2 (UCP2) in the serum of T2DM patients, as well as in HIEC‑6 and SW480 cells following treatment with high glucose and high fat (HGHF). Protein expression was detected by western blotting. Cell Counting Kit‑8 assays were performed to analyze cell viability, and flow cytometry and a TUNEL assay was performed to evaluate cell apoptosis. The secretion of ILs in the culture medium was detected by conducting ELISAs. The results showed that lncRNA TUG1 and UCP2 expression was upregulated, SIRT1 and AMPK expression levels were decreased by SG. Under HGHF conditions, HIEC‑6 and SW480 cell viability was inhibited, apoptosis was promoted, TUG1 expression was downregulated, and SIRT1 and AMPK expression levels were upregulated. The secretory levels of IL‑1β, IL‑6 and IL‑8 were increased, whereas the secretion of IL‑10 was decreased under HGHF conditions. lncRNA TUG1 overexpression significantly reversed the effects of HGHF on cell viability, apoptosis and SIRT1, AMPK, UCP2 and Bcl‑2 expression levels. Together, the findings of the present study demonstrated that lncRNA TUG1 alleviated the damage induced by HGHF in intestinal epithelial cells by downregulating SIRT1 and AMPK expression, and upregulating UCP2 expression. Thus, the lncRNA TUG1/AMPK/SIRT1/UCP2 axis may serve an important role in the treatment of T2DM.

LncRNA KCNQ1OT1 promotes apoptosis and oxidative stress of human lens epithelial cells through epigenetic regulation of WRN

PURPOSE

Long non-coding RNA KCNQ1OT1 is fundamental to age-related cataract (ARC), whereas the underlying mechanism is still unknown. Here, we explored the possible mechanism of KCNQ1OT1 in ARC.

METHODS

The expression of KCNQ1OT1 in ARC patients and H₂O₂-treated human lens epithelial cell line SRA01/04 was detected. Gene and protein expression were examined by quantitative real-time PCR and western blot. Cell viability and apoptosis were detected by CCK-8 assay and flow cytometry. The content of reactive oxygen species (ROS) was assessed by fluorescent probe DCFH-DA. The relationship among KCNQ1OT1, G9a, H3K9me1/2 and WRN was verified by RNA pull down and Chromatin immunoprecipitation.

RESULTS

KCNQ1OT1 was up-regulated in the anterior lens capsule tissues of ARC patients and H₂O₂-treated SRA01/04 cells. KCNQ1OT1 overexpression suppressed cell viability and facilitated apoptosis in H₂O₂-treated SRA01/04 cells. KCNQ1OT1 up-regulation enhanced the levels of ROS and malondialdehyde (MDA), and reduced the levels of superoxide dismutase (SOD) and catalase (CAT) in H₂O₂-treated SRA01/04 cells. WRN up-regulation led to a result opposite to KCNQ1OT1 overexpression. The influence of WRN up-regulation on cell viability, apoptosis and oxidative stress of SRA01/04 cells was rescued by KCNQ1OT1 overexpression. Additionally, KCNQ1OT1 interacted with G9a. Both G9a and H3K9me1/2 interacted with WRN promoter. G9a deficiency significantly enhanced WRN expression and repressed H3K9me1/2 expression in SRA01/04 cells, which was abrogated by KCNQ1OT1 up-regulation.

CONCLUSION

This study demonstrated that KCNQ1OT1 promoted apoptosis and oxidative stress of human LECs through G9a-driven epigenetic regulation of WRN. This work highlights a novel lncRNA involving key regulators of ARC.

Integrated Dissection of lncRNA-miRNA-mRNA Pairs and Potential Regulatory Role of lncRNA PCAT19 in Lung Adenocarcinoma

Lung adenocarcinoma (LUAD) is the main cause of cancer-related deaths worldwide. Long noncoding RNAs have been reported to play an important role in various cancers due to their special functions. Therefore, identifying the lncRNAs involved in LUAD tumorigenesis and development can help improve therapeutic strategies. The TCGA-LUAD RNA expression profile was downloaded from The Cancer Genome Atlas, and a total of 49 differential lncRNAs, 112 differential miRNAs, and 2,953 differential mRNAs were screened. Through Kaplan–Meier curves, interaction networks, hub RNAs (lncRNAs, miRNAs, and mRNAs) were obtained. These hub genes are mainly involved in cell proliferation, cell cycle, lung development, and tumor-related signaling pathways. Two lncRNAs (SMIM25 and PCAT19) more significantly related to the prognosis of LUAD were screened by univariate Cox analysis, multivariate Cox analysis, and risk model analysis. The qPCR results showed that the expression levels of SMIM25 and PCAT19 were downregulated in clinical tissues, A549 and SPC-A1 cells, which were consistent with the bioinformatics analysis results. Subsequently, the PCAT19/miR-143-3p pairs were screened through the weighted gene co-expression network analysis and miRNA-lncRNA regulatory network. Dual luciferase detection confirmed that miR-143-3p directly targets PCAT19, and qPCR results indicated that the expression of the two is positively correlated. Cell function tests showed that overexpression of PCAT19 could significantly inhibit the proliferation, migration, and invasion of A549 and SPC-A1 cells. In contrast, knockout of PCAT19 can better promote the proliferation and migration of A549 and SPC-A1 cells. The expression of PCAT19 was negatively correlated with tumor grade, histological grade, and tumor mutation load in LUAD. In addition, co-transfection experiments confirmed that the miR-143-3p mimic could partially reverse the effect of PCAT19 knockout on the proliferation of A549 and SPC-A1 cells. In summary, PCAT19 is an independent prognostic factor in patients with LUAD that can regulate the proliferation, migration, and invasion of LUAD cells and may be a potential biomarker for the diagnosis of LUAD. PCAT19/miR-143-3p plays a very important regulatory role in the occurrence and development of LUAD.

Long non-coding RNA TPTEP1 exerts inhibitory effects on hepatocellular carcinoma by impairing microRNA-454-3p-mediated DLG5 downregulation

BACKGROUND

Hepatocellular carcinoma (HCC) is usually diagnosed at late stages, making it the second cause of malignancy-related death across the world. Long noncoding RNAs (lncRNAs) are of significance to tumorigenesis, highly suggestive of their functional roles as novel biomarkers for cancer therapy. The current study investigated the specific role of lncRNA TPTE pseudogene 1 (TPTEP1) in HCC.

METHODS

Expression of lncRNA TPTEP1, microRNA-454-3p (miR-454-3p) and discs large homolog 5 (DLG5) was determined in tissues samples from the recruited patients with HCC. Cell proliferation, migration and invasion assays were performed to determine effects of lncRNA TPTEP1, miR-454-3p and DLG5 on the malignant phenotype of tumor cells. Finally, the mouse HCC model was also established to disclose the tumor suppressor effects of lncRNA TPTEP1 in vivo.

RESULTS

LncRNA TPTEP1 was downregulated both in HCC cells and tissues, and played a negative regulatory role in HCC cell proliferation, migration and invasion. Mechanistically, lncRNA TPTEP1 competitively bound to miR-454-3p, thereby upregulating its endogenous target DLG5. Moreover, lncRNA TPTEP1 hindered activation of the protein kinase B signaling pathway, causing inhibited malignant phenotypes of HCC cells. Also, lncRNA TPTEP1 suppressed tumor growth and extrahepatic metastasis (lung) via miR-454-3p/DLG5 axis.

CONCLUSION

Taken together, this research revealed a concrete mechanism of lncRNA TPTEP1 in HCC.

Genomic and functional conservation of lncRNAs: lessons from flies

Over the last decade, the increasing interest in long non-coding RNAs (lncRNAs) has led to the discovery of these transcripts in multiple organisms. LncRNAs tend to be specifically, and often lowly, expressed in certain tissues, cell types and biological contexts. Although lncRNAs participate in the regulation of a wide variety of biological processes, including development and disease, most of their functions and mechanisms of action remain unknown. Poor conservation of the DNA sequences encoding for these transcripts makes the identification of lncRNAs orthologues among different species very challenging, especially between evolutionarily distant species such as flies and humans or mice. However, the functions of lncRNAs are unexpectedly preserved among different species supporting the idea that conservation occurs beyond DNA sequences and reinforcing the potential of characterising lncRNAs in animal models. In this review, we describe the features and roles of lncRNAs in the fruit fly Drosophila melanogaster, focusing on genomic and functional comparisons with human and mouse lncRNAs. We also discuss the current state of advances and limitations in the study of lncRNA conservation and future perspectives.

Long non‑coding RNA MBI‑52 inhibits the development of liver fibrosis by regulating the microRNA‑466g/SMAD4 signaling pathway

Liver fibrosis is a wound healing response triggered by liver injury. In severe cases, it may develop into liver cirrhosis, liver cancer and liver failure. Long non-coding RNAs (lncRNAs) play key roles in the development of liver fibrosis. The present study aimed to investigate the role of lncRNA-MBI-52 (lnc-MBI-52) in the progression of liver fibrosis. Carbon tetrachloride (CCl₄)-induced injury was performed to establish a mouse liver fibrosis model, and exogenous transforming growth factor-β1 was used to establish a hepatic stellate cell (HSC) activation model. Reverse transcription-quantitative PCR and western blot analyses were performed to detect mRNA and protein expression, respectively. RNA pull-down assay was performed to assess the interaction between microRNA (miR)-466g and lnc-MBI-52 or SMAD4. Dual-luciferase reporter assay was performed to verify the target of miR-466g. lnc-MBI-52 was overexpressed in CCl₄-induced mouse liver fibrosis models and activated HSCs. lnc-MBI-52 knockdown suppressed liver fibrosis in vitro. Moreover, knockdown of lnc-MBI-52 downregulated α-smooth muscle actin and collagen type I expression. In addition, lnc-MBI-52 and SMAD4 were identified as targets of miR-466g. The effects of lnc-MBI-52 on HSC activation were reversed following transfection with miR-466g mimics or SMAD4 knockdown. lnc-MBI-52 miR-466g significantly decreased lnc-MBI-52 expression, while overexpression of lnc-MBI-52 suppressed miR-466g expression. The results of the RNA pull-down assay confirmed the interaction between miR-466g and lnc-MBI-52. Taken together, lnc-MBI-52 induced liver fibrosis by regulating the miR-466g/SMAD4 axis, which may provide a new possible strategy for liver fibrosis.

Clinical significance and effect of lncRNA BBOX1-AS1 on the proliferation and migration of lung squamous cell carcinoma

Long non-coding RNAs (lncRNAs) have a role in the occurrence and development of lung squamous cell carcinoma (LUSC). lncRNA γ-butyrobetaine hydroxylase 1 (BBOX1)-antisense 1 (AS1) may contribute to disease development. However, there are no studies on the role of BBOX1-AS1 in LUSC to date. In the present study, an in-house gene microarray analysis was performed to detect the differentially expressed lncRNAs and mRNAs between three pairs of LUSC and normal lung tissues. Only one lncRNA, BBOX1-AS1, was differentially expressed in the in-house microarray and The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO) and ArrayExpress databases. Reverse transcription-quantitative PCR (RT-qPCR) was then performed and the original RNA-sequencing data from the TCGA, GEO and ArrayExpress datasets were used to determine the expression and clinical value of BBOX1-AS1 in LUSC. In addition, a Cell Counting Kit-8 assay, cell cycle analysis and scratch assay were performed to explore whether BBOX1-AS1 expression affected the proliferation and migration of LUSC cells in vitro. The results of the RT-qPCR analysis and data obtained from the TCGA database, GEO datasets, in-house gene microarray and standard mean deviation analysis all supported the upregulated expression level of BBOX1-AS1 in LUSC. Furthermore, silencing of BBOX1-AS1 inhibited the proliferation and migration of LUSC cells according to in vitro assays. In addition, the cells were arrested in S-phase after knockdown of BBOX1-AS1. In conclusion, the expression level of BBOX1-AS1 was upregulated in LUSC tissues. BBOX1-AS1 may exert an oncogenic effect on LUSC by regulating various biological functions. However, additional functional experiments should be performed to verify the exact mechanism.

Baseline lncRNA PCAT1 high expression and its longitude increment during induction therapy predict worse prognosis in multiple myeloma patients

BACKGROUND

Long noncoding RNA PCAT1 (lnc-PCAT1) involves in the proliferation and drug sensitivity of multiple myeloma (MM), while its prognostic role in MM patients is still obscure. This study aimed to explore the association of lnc-PCAT1 with MM risk, clinical characteristics, treatment response, progression-free survival (PFS), and overall survival (OS).

METHODS

A total of 83 symptomatic MM patients were enrolled in this study. Additionally, 30 healthy bone marrow donors as health controls were also recruited. Bone marrow plasma cell samples of MM patients and health donors were collected. Lnc-PCAT1 in bone marrow plasma cells was detected by reverse transcription-quantitative polymerase chain reaction.

RESULTS

Lnc-PCAT1 was increased in MM patients than in health donors (p < 0.001), and receiver operating characteristic (ROC) curve showed that lnc-PCAT1 had excellent capability of discriminating MM patients from health donors (area under curve: 0.932, 95% confidence interval: 0.889-0.976). In MM patients, lnc-PCAT1 was correlated with bone lesion (p = 0.024), higher β2 -MG (p = 0.005), LDH (p = 0.037), and presence of Del (17p) (p = 0.029). Lnc-PCAT1 was also associated with poor ISS stage (p = 0.013) and R-ISS stage (p = 0.005). Besides, lnc-PCAT1 was reduced after treatment (p < 0.001); meanwhile, lnc-PCAT1 before treatment was correlated with lower CR (p = 0.046) but not ORR (p = 0.185). Additionally, lnc-PCAT1 after treatment was associated with lower CR (p = 0.003) and ORR (p = 0.010). Furthermore, baseline Inc-PCAT1 high and Inc-PCAT1 increase after treatment were correlated with worse PFS and OS (all p < 0.05).

CONCLUSION

Lnc-PCAT1 dysregulation serves as a biomarker for diagnosis and prognosis for MM.

Regulation of Metabolic Reprogramming by Long Non-Coding RNAs in Cancer

Metabolic reprogramming is a well described hallmark of cancer. Oncogenic stimuli and the microenvironment shape the metabolic phenotype of cancer cells, causing pathological modifications of carbohydrate, amino acid and lipid metabolism that support the uncontrolled growth and proliferation of cancer cells. Conversely, metabolic alterations in cancer can drive changes in genetic programs affecting cell proliferation and differentiation. In recent years, the role of non-coding RNAs in metabolic reprogramming in cancer has been extensively studied. Here, we review this topic, with a focus on glucose, glutamine, and lipid metabolism and point to some evidence that metabolic alterations occurring in cancer can drive changes in non-coding RNA expression, thus adding an additional level of complexity in the relationship between metabolism and genetic programs in cancer cells.

LncRNA LINC00467 acted as an oncogene in esophageal squamous cell carcinoma by accelerating cell proliferation and preventing cell apoptosis via the miR-485-5p/DPAGT1 axis

BACKGROUND AND AIM

Esophageal carcinoma has been regarded as one of the top 10 common malignancies globally. Esophageal squamous cell carcinoma (ESCC) is an important subtype of esophageal carcinoma with approximately 20% survival rate. Long noncoding RNAs were documented to regulate the occurrence or progression of several tumors. However, neither the biological role nor the molecular mechanism of LINC00467 has been explored. This research is aimed to investigating the regulatory mechanism of LINC00467 in ESCC.

METHODS

In this study, a series of experiments including reverse transcription-quantitative polymerase chain reaction, Cell Counting Kit-8, luciferase reporter, western blot, and RNA immunoprecipitation were designed and conducted to explore the potential function and mechanism of LINC00467 in ESCC.

RESULTS

According to experimental results, we found out upregulated LINC00467 improved cell proliferation, but hindered cell apoptosis. In mechanism, miR-485-5p was predicted, screened out, and validated to combine with LINC00467, which displayed lower expression in ESCC. Additionally, miR-485-5p negatively regulated and directly targeted DPAGT1. Rescue assays suggested that DPAGT1 amplification was able to recover the influence of LINC00467 deficiency on cell proliferation and apoptosis. Furthermore, knockdown of LINC00467 suppressed tumor growth in vivo.

CONCLUSION

We proved that LINC00467 acted as an oncogene in ESCC by accelerating cell proliferation and preventing cell apoptosis via miR-485-5p/DPAGT1 axis. This may provide a potential diagnostic marker for ESCC treatment.

Identification of Potential Therapeutic Targets and Pathways of Liraglutide Against Type 2 Diabetes Mellitus (T2DM) Based on Long Non-Coding RNA (lncRNA) Sequencing

BACKGROUND The aim of this study was to explore the potential therapeutic targets and pathways of liraglutide against type 2 diabetes mellitus (T2DM) in streptozotocin-induced diabetic rats based on lncRNA sequencing. MATERIAL AND METHODS Male Wistar rats were randomly divided into 3 groups: the control group (n=10), the T2DM model group (high-sugar and high-fat diet, and streptozotocin-induced, n=11), and the liraglutide group (model plus liraglutide, n=10). After 8 weeks of drug treatment, lncRNA sequencing was used to identify the lncRNA therapeutic targets and their related protein-coding genes of liraglutide against T2DM, which were further studied by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis to determine the major biological processes and pathways involved in the action of liraglutide treatment. Lastly, several lncRNA targets were randomly detected based on quantitative real-time polymerase chain reaction (QRT-PCR) to verify the accuracy of sequencing results. RESULTS A total of 104 lncRNA targets of liraglutide against T2DM were screened, with 27 upregulated and 77 downregulated, including NONRATT030354.2, MSTRG.1456.6, and NONRATT011758.2. The major biological processes involved were glucose and lipid metabolism and amino acid metabolism. Liraglutide had a therapeutic effect in T2DM, mainly through the Wnt, PPAR, amino acid metabolism signaling, mTOR, and lipid metabolism-related pathways. CONCLUSIONS In this study, we screened 104 lncRNA therapeutic targets and several signaling pathways (Wnt, PPAR, amino acid metabolism signaling pathway, mTOR, and lipid metabolism-related pathways) of liraglutide against T2DM based on lncRNA sequencing.