lncRNA LUCAT1 Research Articles

Role of lncRNA LUCAT1 in Promoting Radioresistance of Lung Cancer Cells through Sponging with miR-199a-5p

Role of lncRNA LUCAT1 in Promoting Radioresistance of Lung Cancer Cells through Sponging with miR-199a-5p

Low LncRNA LUCAT1 Expression Assists in the Diagnosis of Chronic Heart Failure and Predicts Poor Prognosis.

Chronic heart failure (CHF) is a complicated syndrome caused by structural and functional abnormalities. Long noncoding RNA (LncRNA) lung cancer-associated transcript 1 (LUCAT1) downregulation inhibits cardiomyocyte apoptosis. This study aimed to measure LUCAT1 expression in patients with CHF and to explore its clinical value on CHF diagnosis and prognosis. A total of 94 patients with CHF and 90 participants without CHF were registered, followed by recording of their clinical characteristics and grading of their cardiac function. LUCAT1 expression in sera of patients with CHF and participants without CHF was detected. The correlation of LUCAT1 with brain natriuretic peptide (BNP) and left ventricular ejection fraction (LVEF) in patients with CHF and the diagnostic efficiency of LUCAT1, BNP, and LUCAT1 combined with BNP on patients with CHF were analyzed. Patients with CHF were treated with conventional drugs and followed up. The LUCAT1 expression in patients with CHF was lower than that in participants without CHF and was downregulated with the increase of New York Heart Association stage. LUCAT1 expression was negatively associated with BNP but positively associated with LVEF in the sera of patients with CHF. The receiver operating characteristic curve of LUCAT1 combined with BNP had better result than that of LUCAT1 and BNP alone. Low LUCAT1 expression indicated poor prognosis of patients with CHF and was an independent prognostic factor for the survival of patients with CHF. To summarize, low lncRNA LUCAT1 expression might help diagnose and predict the poor prognosis of CHF.

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

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

Single-cell RNA sequencing uncovers the nuclear decoy lincRNA PIRAT as a regulator of systemic monocyte immunity during COVID-19

The systemic immune response to viral infection is shaped by master transcription factors, such as NF-κB, STAT1, or PU.1. Although long noncoding RNAs (lncRNAs) have been suggested as important regulators of transcription factor activity, their contributions to the systemic immunopathologies observed during SARS-CoV-2 infection have remained unknown. Here, we employed a targeted single-cell RNA sequencing approach to reveal lncRNAs differentially expressed in blood leukocytes during severe COVID-19. Our results uncover the lncRNA PIRAT (PU.1-induced regulator of alarmin transcription) as a major PU.1 feedback-regulator in monocytes, governing the production of the alarmins S100A8/A9, key drivers of COVID-19 pathogenesis. Knockout and transgene expression, combined with chromatin-occupancy profiling, characterized PIRAT as a nuclear decoy RNA, keeping PU.1 from binding to alarmin promoters and promoting its binding to pseudogenes in naïve monocytes. NF-κB-dependent PIRAT down-regulation during COVID-19 consequently releases a transcriptional brake, fueling alarmin production. Alarmin expression is additionally enhanced by the up-regulation of the lncRNA LUCAT1, which promotes NF-κB-dependent gene expression at the expense of targets of the JAK-STAT pathway. Our results suggest a major role of nuclear noncoding RNA networks in systemic antiviral responses to SARS-CoV-2 in humans.

Key LncRNAs Associated With Oxidative Stress Were Identified by GEO Database Data and Whole Blood Analysis of Intervertebral Disc Degeneration Patients.

Background: Intervertebral disc degeneration (IDD) is a major cause of low back pain, but the onset and progression of IDD are unknown. Long non-coding RNA (lncRNA) has been validated to play a critical role in IDD, while an increasing number of studies have linked oxidative stress (OS) to the initiation and progression of IDD. We aim to investigate key lncRNAs in IDD through a comprehensive network of competing endogenous RNA (ceRNA) and to identify possible underlying mechanisms. Methods: We downloaded IDD-related gene expression data from the Gene Expression Omnibus (GEO) database and obtained differentially expressed-lncRNAs (DE-lncRNA), -microRNAs (DE-miRNA), and -messenger RNAs (DE-mRNA) by bioinformatics analysis. The OS-related lncRNA-miRNA-mRNA ceRNA interaction axis was constructed and key lncRNAs were identified based on ceRNA theory. We performed gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses on mRNAs regulated by lncRNAs in the ceRNA network. Single sample gene set enrichment analysis (ssGSEA) was used to reveal the immune landscape. Expression of key lncRNAs in IDD was assessed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Results: In this study, 111 DE-mRNAs, 20 DE-lncRNAs, and 502 DE-miRNAs were identified between IDD patients and controls, and 16 OS-related DE-lncRNAs were also identified. The resulting lncRNA-miRNA-mRNA network consisted of eight OS-related DE-lncRNA nodes, 24 DE-miRNA nodes, 70 DE-mRNA nodes, and 183 edges. Functional enrichment analysis suggested that the ceRNA network may be involved in regulating biological processes related to cytokine secretion, lipid, and angiogenesis. We also identified four key lncRNAs, namely lncRNA GNAS-AS1, lncRNA MIR100HG, lncRNA LINC01359, and lncRNA LUCAT1, which were also found to be significantly associated with immune cells. Conclusion: These results provide novel insights into the potential applications of OS-related lncRNAs in patients with IDD.

Increased expression of prokineticin 2 and its receptor in endometrium of recurrent implantation failure patients decreased the expression of MMP9 important for decidualization

BackgroundStudies have shown that abnormalities in the decidualization process were closely related to recurrent implantation failure (RIF). Prokineticin 2 (PK2) is a secreted protein with angiogenic and tissue remodeling functions but its role in the endometrium is unknown.MethodsPK2 levels and its receptor PKR1 mRNA and protein levels in mid-secretory endometrium from normal and RIF women were examined by real-time PCR and western blotting, respectively. The effects of PK2 were evaluated by overexpressed PK2 in immortalized endometrial T-HESC cells using lentivirus vector and found different expression of Matrix metalloproteinase 9(MMP9) and lncRNA LUCAT1 by RNA-sequencing. The ability of PK2 to regulate LUCAT1 and MMP9 was verified in endometrial cells by real-time PCR and western blotting.ResultsUsing endometrial biopsies from normal and RIF patients, we found increased expression of PK2, together with its receptor PKR1 in RIF patients. We then overexpressed PK2 in immortalized endometrial T-HESC cells using lentivirus vector and found decreased expression of Matrix metalloproteinase 9(MMP9), and increased expression of lncRNA LUCAT1. We verified the ability of PK2 to stimulate LUCAT1 and decrease MMP9 in endometrial cells. We further demonstrated that increased expression of a long noncoding RNA LUCAT1 and decreased expression of MMP9 in endometrial biopsies of patients with RIF. Thus, we highlighted the important role of PK2 and its receptor PKR1 in decidualization and RIF.ConclusionProkineticin 2 and its receptor are important in endometrium decidualization. PK2 may affect endometrial decidualization through the LUCAT1- MMP9 pathway, thereby affecting embryo implantation.

Knockdown of lncRNA LUCAT1 attenuates sepsis‑induced myocardial cell injury by sponging miR-642a.

The heart is one of the most common organs involved in sepsis-induced organ dysfunction and about 50% septic patients complicated with myocardial injury. So far, the molecular mechanisms underlying sepsis-induced cardiac damage remain unclear. In this study we aimed to evaluate the effect of miR-642a on sepsis-induced cardiac injury in vitro and explore the possible lncRNA-microRNA mechanism. We first downloaded GSE101639 to identify differentially expressed genes (DEGs) in sepsis. The expression of miR-642a in LPS-induced H9C2 cells was detected by qRT-PCR. MTT assay, cell migration, flow cytometry analysis, ELISA, qRT-PCR and Western blotting analysis were applied to evaluating the effect of miR-642a mimic on LPS-induced H9C2 cells. The bioinformatics analysis and the rescue experiment were devoted to the underlying mechanism. The results showed miR-642a expression was decreased in septic patients and LPS-induced H9C2 cells. Besides, MiR-642a mimic promoted cell viability and migration, inhibited cell apoptosis of LPS-induced H9C2 cells. Bioinformatics analysis showed miR-642a directly targets with 3'-UTR of ROCK1. Moreover, LUCAT1 regulated ROCK1 expression act as a competing endogenous RNA (ceRNA) for miR-642a. Our data demonstrated that lncRNA LUCAT1 could function via sponging miR-642a to regulate ROCK1 expression in LPS-induced H9C2 cells. And knockdown of lncRNA LUCAT1 could suppress LPS-induced cardiac injury in vitro.

Expression of long non-coding RNA LUCAT1 in patients with chronic obstructive pulmonary disease and its potential functions in regulating cigarette smoke extract-induced 16HBE cell proliferation and apoptosis.

BackgroundChronic obstructive pulmonary disease (COPD), characterized by persistent airflow limitation, was a disease mediated by a combination of inflammatory factors, immune cells, and immune mediators. COPD was an inflammatory and autoimmune disease involving T‐lymphocytes triggered by cigarette smoke and other factors that progressively affected the bronchi, lung parenchyma, and pulmonary blood vessels. LncRNAs were reported to be implicated in COPD pathogenesis and development.MethodsNon‐smokers, smokers (non‐COPD), and COPD patients were randomly selected in an established COPD surveillance cohort. Demographic and clinical information of all subjects were collected. Pulmonary function was measured by post‐bronchodilator testing. qRT‐PCR and ELISA assays were performed to detect the expression levels of lncRNA LUCAT1, miR‐181a‐5p, and inflammatory cytokines. An in vitro exposure model was constructed using cigarette smoke extract (CSE)‐induced human bronchial epithelial (16HBE) cells. The dual‐luciferase reporter and RNA pull‐down assays were used to detect the binding relationship between lncRNA LUCAT1 and miR‐181a‐5p; meanwhile, Spearman's correlation assay was used to verify the correlation between lncRNA LUCAT1 and miR‐181a‐5p. Afterward, the lncRNA LUCAT1 silencing plasmid was constructed and co‐transfected with a miR‐181a‐5p inhibitor to evaluate the effects on CSE‐induced 16HBE cell proliferation and apoptosis. Finally, a Western blot assay was utilized to determine the mechanism of lncRNA LUCAT1/miR‐181a‐5p/Wnt/β‐catenin axis in COPD.ResultsLncRNA LUCAT1 was upregulated in the serums of COPD patients. Correlation analysis further confirmed the strong correlation between LUCAT1 expression and inflammatory cytokines IL‐1β, IL‐6, and TNF‐α. Receiver operating characteristic (ROC) analysis verified the potential of LUCAT1 in COPD diagnosis. After treatment with CSE, LUCAT1 was significantly increased while its target miR‐181a‐5p was decreased in 16HBE cells. Cell proliferation and apoptosis assays showed that LUCAT1 silencing alleviated CSE’s effects on 16HBE cell proliferation and apoptosis. Mechanically, rescue assays demonstrated that miR‐181a‐5p inhibition could partially counteract the impact of LUCAT1 on COPD progression through the Wnt/β‐catenin pathway.ConclusionsLncRNA LUCAT1 may be a valuable indicator for differentiating COPD. Moreover, LncRNA LUCAT1/miR‐181‐5p/Wnt/β‐catenin axis behaved as a critical role in COPD development, shedding new sights for clinical treatment.

Retraction: Study of the biological function of LncRNA LUCAT1 on cervical cancer cells by targeting miR-199b-5p

Retraction: Study of the biological function of LncRNA LUCAT1 on cervical cancer cells by targeting miR-199b-5p

Retraction: Study of the biological function of LncRNA LUCAT1 on cervical cancer cells by targeting miR-199b-5p.

This Retraction follows an Expression of Concern relating to this article previously published by Portland Press.This article is being retracted from Bioscience Reports at the request of the Editor-in-Chief and the Editorial Board following receipt of a notification from a reader, alerting the Editorial Board to unusual repeated background features in the Western blots.The authors have been contacted in regard to the retraction and were asked to provide the raw images for these Western blots. However as the images provided during the investigation differed from those in the published paper and appear to show signs of editing, the Editorial Board stands by the decision to retract. The authors were asked to agree to the retraction but did not respond to the Editorial Office.

LUCAT1 as an oncogene in tongue squamous cell carcinoma by targeting miR-375 expression.

Emerging studies suggested that lncRNAs play a crucial molecular role in cancer development and progression. LncRNA LUCAT1 has been proved as oncogenic molecular in lung cancer, glioma, osteosarcoma, renal carcinoma and oesophageal squamous cell carcinoma. However, its roles and function mechanisms in tongue squamous cell carcinoma (TSCC) are still unknown. We showed that the expression of LUCAT1 was up‐regulated in the TSCC cells and tissues and the higher LUCAT1 expression was associated with the poor overall survival (OS). Knockdown expression of LUCAT1 suppressed TSCC cell proliferation, cycle and migration. In addition, we demonstrated that miR‐375 overexpression inhibited the luciferase activity of LUCAT1 wild‐type and knockdown LUCAT1 promoted the miR‐375 expression in TSCC cell. Furthermore, we indicated that miR‐375 expression was down‐regulated in the TSCC cell lines and tissues and the lower expression of miR‐375 was associated with poor OS. The expression of miR‐375 was inversely correlated with LUCAT1 expression in the TSCC tissues. Knockdown LUCAT1 promoted TSCC cell proliferation, cell cycle and migration partly through regulating miR‐375 expression. In summary, this study suggested the tumorigenic effect of lncRNA LUCAT1 in TSCC cells by targeting miR‐375 expression.

IncRNA LUCAT1 acts as a Potential Biomarker and Demonstrates Malignant Biological Behaviors in Gastric Cancer

Gastric cancer (GC) remains the fourth-leading malignancy worldwide and has a high mortality rate. Accumulating evidence reveals that long noncoding RNAs (lncRNAs) play essential roles in tumorigenesis and metastasis and can be used as potential biomarkers for diagnosis and prognosis. We downloaded gene expression profiles from the National Center of Biotechnology Information Gene Expression Omnibus (GEO), screened lncRNAs differentially expressed in gastric cancer tissues and adjacent tissues, and then constructed a lncRNA-miRNA-mRNA network. Seventy patients with gastric cancer were divided into two groups according to different clinical characteristics. The expression of lncRNA LUCAT1 in gastric cancer was detected by reverse transcription polymerase chain reaction (RT-PCR). The AGS and SGC-7901 cell lines were used in CCK8 assay, apoptosis, cell cycle test, transwell assay, and wound healing assay. The expression level of LUCAT1 was associated with tumor diameter (p < 0.001), tissue differentiation grade (p = 0.026), and LNM status (p = 0.020) in GC. The results showed that the lncRNA LUCAT1 could promote the proliferation, invasion, and migration of GC cells, inhibit the apoptosis of GC cells, and affect the process of cell cycles. The lncRNA LUCAT1 may be used as a potential biomarker for early signs of LNM in GC and may play a crucial role in the development of GC.

Long non-coding RNA LUCAT1 inhibits myocardial oxidative stress and apoptosis after myocardial infarction via targeting microRNA-181a-5p

ABSTRACT This study hoped to explore the effects and mechanism of long non-coding RNA (lncRNA) LUCAT1 regulating microRNA-181a-5p (miR-181a-5p) on oxidative stress and apoptosis of cardiomyocytes induced by H2O2. Totally, 72 patients with acute myocardial infarction (AMI) were included. H9c2 cardiomyocytes were cultured in vitro, and the H2O2 model of cardiomyocytes was established. The expression levels of LUCAT1 and miR-181a-5p were detected by qRT-PCR after H2O2 induction. The contents of reactive oxygen species (ROS), superoxide dismutase (SOD), and malondialdehyde (MDA) in cells were detected. The survival rate of the cells was detected by the Cell Counting Kit-8 (CCK-8) method; the apoptosis was detected by flow cytometry. The luciferase reporter experiment and quantitative real-time PCR (qRT-PCR) were used to verify the targeted relationship between LUCAT1 and miR-181a-5p. LUCAT1 was lowly expressed in the AMI patients. After H2O2 induction, the expression of LUCAT1 in H9c2 cells lessened significantly, while the expression of miR-181a-5p elevated significantly (P < 0.001). Transfection of p-LUCAT1 significantly reversed the decreased SOD levels, the increased MDA and ROS content, and the elevated tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1 beta (IL-1β) in H2O2-stimulated cells (P < 0.001). Upregulation of LUCAT1 contributed to the mitigation of H2O2 injury by promoting viable cells and repressing apoptotic cells (P < 0.01). LUCAT1 targeted miR-181a-5p and negatively regulated miR-181a-5p expression (P < 0.001). Collectively, LUCAT1 played a protective role on oxidative stress injury, inflammation, viability, and apoptosis of cardiomyocytes induced by H2O2 via regulating miR-181a-5p.

The progression of pancreatic cancer cells is promoted by a long non-coding RNA LUCAT1 by activating AKT phosphorylation.

In many cancers, long non-coding RNAs (lncRNA) are largely involved; they can regulate cell proliferation, migration, and invasion. However, the research of lncRNA regulation on pancreatic ductal adenocarcinoma is vacant. The aim of this article was to lucubrate the specific role of lncRNA LUCAT1 in regulating the progression of pancreatic cancer. Pancreatic cancer and adjacent tissues were collected, and the expression of LUCAT1, one potential involved LucRNA, was measured using real-time qPCR (RT-qPCR). Different pathological types of pancreatic cancer cell lines were cultured, and the expression difference of LncRNA LUCAT1 was detected by RT-qPCR, and two cell lines were selected for downstream experiments. si-RNA was used to knockdown the expression of LUCAT1, comparing the difference in expression of LUCAT1, characterizing cell proliferation by MTT and BrdU staining, detecting apoptosis, and cell cycle changes by flow cytometry. Meanwhile, Western blotting was used for the detection of cyclin expression and thus investigate two important associated signaling pathways. Besides, the expression of signaling pathway was validated by signaling inhibitor. In comparison to normal cells, LUCAT1 was highly expressed in human pancreatic cancer cell lines (p<0.05). The higher expression of LUCAT1 resulted in enhanced pathogenesis of PDA cells and motivated the development to S phase by regulation of cyclin D1, CDK4. Furthermore, LUCAT1 promoted PDA cells development by inducing AKT's and p38 MAPK's phosphorylation. LUCAT1, as the key factor, played a positive role in the proliferation and invasion of pancreatic cells via AKT/MAPK signaling.

The long non-coding RNA LUCAT1 is a negative feedback regulator of interferon responses in humans

Long non-coding RNAs are important regulators of biological processes including immune responses. The immunoregulatory functions of lncRNAs have been revealed primarily in murine models with limited understanding of lncRNAs in human immune responses. Here, we identify lncRNA LUCAT1 which is upregulated in human myeloid cells stimulated with lipopolysaccharide and other innate immune stimuli. Targeted deletion of LUCAT1 in myeloid cells increases expression of type I interferon stimulated genes in response to LPS. By contrast, increased LUCAT1 expression results in a reduction of the inducible ISG response. In activated cells, LUCAT1 is enriched in the nucleus where it associates with chromatin. Further, LUCAT1 limits transcription of interferon stimulated genes by interacting with STAT1 in the nucleus. Together, our study highlights the role of the lncRNA LUCAT1 as a post-induction feedback regulator which functions to restrain the immune response in human cells.

Long Non-Coding RNA LUCAT1 Promotes Progression of Thyroid Carcinoma by Reinforcing ADAM10 Expression Through Sequestering microRNA-493.

BackgroundLong non-coding RNA (lncRNA) LUCAT1 has recently been recognized as an oncogene in several malignancies. This study was launched to probe its role in thyroid carcinoma (TC) development and the implicated molecules.MethodsLUCAT1 expression in TC cell lines and in normal thyroid follicular epithelial cell line Nthy-ori3-1 was determined by RT-qPCR. Binding relationships between LUCAT1 and microRNA (miR)-493, and between miR-493 and a disintegrin and metalloproteinase-10 (ADAM10) were predicted on a bioinformatics system and then validated through luciferase reporter gene assays. Expression of miR-493 and ADAM10 in TC cells was determined. Gain- and loss-of functions of LUCAT1, miR-493 and ADAM10 were performed to explore their influences on the behaviors of TC cells. Xenograft tumors were induced in nude mice for in vivo studies.ResultsLUCAT1 and ADAM10 were highly expressed, while miR-493 was poorly expressed in TC cell lines. LUCAT1 served as a miR-493 sponge to upregulate ADAM10 expression. Silencing of LUCAT1 discouraged proliferation, invasion, and migration but triggered apoptosis of TC cells. By contrast, these changes were abrogated by further miR-493 inhibition or ADAM10 upregulation. The in vitro experiment results were reproduced in vivo. In addition, miR-493 inhibition or ADAM10 overexpression was found to increase the phosphorylation of STAT3 in cells.ConclusionThis study evidenced that LUCAT1 increases ADAM10 expression through sequestering miR-493, leading to JAK-STAT activation and TC cell growth and metastasis. LUCAT1 and ADAM10 may serve as therapeutic targets for TC treatment.

The long noncoding RNA LUCAT1 promotes colorectal cancer cell proliferation by antagonizing Nucleolin to regulate MYC expression

The long noncoding RNA (lncRNA) LUCAT1 was recently reported to be upregulated and to play an essential role in multiple cancer types, especially colorectal cancer (CRC), but the molecular mechanisms of LUCAT1 in CRC are mostly unreported. Here, a systematic analysis of LUACT1 expression is performed with data from TCGA database and clinic CRC samples. LUCAT1 is identified as a putative oncogene, which is significantly upregulated in CRC and is associated with poor prognosis. Loss of LUCAT1 restricts CRC proliferative capacities in vitro and in vivo. Mechanically, NCL is identified as the protein binding partner of LUCAT1 by using chromatin isolation by RNA purification coupled with mass spectrometry (ChIRP-MS) and RNA immunoprecipitation assays. We also show that NCL directly binds to LUCAT1 via its putative G-quadruplex-forming regions from nucleotides 717 to 746. The interaction between LUCAT1 and NCL interferes NCL-mediated inhibition of MYC and promote the expression of MYC. Cells lacking LUCAT1 show a decreased MYC expression, and NCL knockdown rescue LUCAT1 depletion-induced inhibition of CRC cell proliferation and MYC expression. Our results suggest that LUCAT1 plays a critical role in CRC cell proliferation by inhibiting the function of NCL via its G-quadruplex structure and may serve as a new prognostic biomarker and effective therapeutic target for CRC.

LncRNA LUCAT1/miR-181a-5p axis promotes proliferation and invasion of breast cancer via targeting KLF6 and KLF15

BackgroundLong non-coding RNAs (lncRNAs) are novel regulatory molecules in breast cancer development. LncRNA LUCAT1 is a potential tumor promoter in human cancers. In this study, we aimed to explore the role of LUCAT1 in human breast cancer tissues and cells.MethodsA total of 31 breast cancer patients who underwent tumor resection, but without chemo- or radiotherapy or acute lung/heart/kidney diseases, provided tumor and adjacent normal tissues. Bioinformatic analysis, qRT-PCR, and luciferase reporter assay were carried out during the study.ResultsqRT-PCR analysis indicated that, compared with the adjacent tissues and MCF-10A normal breast epithelial cells, LUCAT1 was markedly up-regulated in the breast cancer tissues and five BC cell lines, including MDA-MB-231, MDA-MB-468, MDA-MB-435, SKBR3, and MCF-7. The knockdown of LUCAT1, through the transfection of small interfering RNA (siRNA) specific to LUCAT1, resulted in inhibition of proliferation in breast cancer cells. The expression levels of miR-181a-5p were decreased in the breast cancer tissues and five BC cell lines. Bioinformatic analysis and luciferase reporter assay suggested the interaction between miR-181a-5p and LUCAT1. In addition, the effects of LUCAT1 on promoting cell proliferation were attenuated by overexpression of miR-181a-5p through the transfection of miR-181a-5p mimic. Moreover, bioinformatics and luciferase reporter assay confirmed that miR-181a-5p targeted the 3′-UTR region of KLF6 and KLF15 mRNA, which were two tumor suppressor genes. LUCAT1/miR-181a-5p axis regulated the expression of KLF6 and KLF15 both in vitro and in vivo.ConclusionsOur data indicate that LUCAT1/miR-181a-5p axis can serve as a novel therapeutic target in breast cancer.

Prognostic value of long non-coding RNAs in triple negative breast cancer: A PRISMA-compliant meta-analysis.

BackgroundTriple-negative breast cancer (TNBC) is the most aggressive and lethal subtype of breast cancer. Accumulating evidence showed long non-coding RNAs (lncRNAs) are abnormally expressed in TNBC and could be valuable prognostic tools for TNBC patients. This study aims to research the prognostic value of lncRNAs in TNBC, using the meta-analysis method.MethodsWe performed a detailed literature search on Pubmed, Scopus, and Web of Science for studies on the prognostic value of lncRNAs in TNBC. The meta-analysis method was used to determine the relationship between lncRNAs expression and survival of TNBC patients.ResultsA total of 2803 TNBC patients and 24 lncRNAs from 27 different articles were included in the present study. Subgroup analysis demonstrated that overexpression of lncRNAs in a group that is upregulated in TBNC showed a significant association with poor overall survival (HR = 1.86, 95%CI = 1.45–2.27, I2 = 41.9%) and disease-free survival (HR = 1.85, 95%CI = 1.37–2.33, I2 = 0%). Conversely, overexpression of lncRNAs in a downregulation group was markedly related to good overall survival (HR = 0.60, 95%CI = 0.43–0.77, I2 = 28.6%). Moreover, expression of lncRNA SNHG12, MALAT1, HOTAIR, HIF1A-AS2, HULC, LINC00096, ZEB2-AS1, LUCAT1, and LINC000173 showed a marked correlation with positive lymph node metastasis (LNM), while lncRNA MIR503HG, GAS5, TCONS_l2_00002973 showed the opposite effect. High expression level of MALAT1, HIF1A-AS2, HULC, LINC00096, ADPGK-AS1, ZEB2-AS1, LUCAT1 were positively correlated with distant metastasis (DM), while lncRNA MIR503HG showed the opposite effect. In addition, the mechanisms of lncRNAs in TNBC were summarized.ConclusionsThis meta-analysis demonstrated that abnormally expressed lncRNA were significantly associated with the survival of TNBC patients and may serve as biomarkers and therapeutic targets for TNBC prognosis.

Expression of Concern: Study of the biological function of LncRNA LUCAT1 on cervical cancer cells by targeting miR-199b-5p.

The Editorial Office has been made aware of potential issues surrounding the scientific validity of this paper, hence has issued an expression of concern to notify readers whilst the Editorial Office investigates.