Non-coding RNA Metastasis-associated Lung Adenocarcinoma Research Articles

LncRNA MALAT1 Promotes Tumor Angiogenesis by Regulating MicroRNA-150-5p/VEGFA Signaling in Osteosarcoma: In-Vitro and In-Vivo Analyses.

The present study aims to analyze the expression of long noncoding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in human osteosarcoma (OS) cells and to investigate its role in OS-induced angiogenesis. MALAT1 expression in OS cells was significantly higher than in normal osteoblasts. The functional analysis indicated that MALAT1 appears to enhance OS-induced angiogenesis, in vitro and in vivo analyses, endothelial cell proliferation and migration, chick embryo angiogenesis assay, and zebrafish xenograft model. Mechanistically, silencing MALAT1 downregulated vascular endothelial growth factor A (VEGFA) expression and upregulated miR-150-5p expression in OS cells, and MALAT1-mediated angiogenic induction by VEGFA in OS microenvironment. Moreover, MALAT1 directly targeted miR-150-5p and miR-150-5p directly target VEGFA in OS. Overexpression of miR-150-5p downregulates VEGFA expression in OS. More notably, we showed that MALAT1 induced angiogenesis in OS microenvironment by upregulating the expression of VEGFA via targeting miR-150-5p. Overall, our findings suggest that MALAT1 promotes angiogenesis by regulating the miR-150-5p/VEGFA signaling in OS microenvironment. The findings of the molecular mechanisms of MALAT1 in tumor angiogenesis offer a new viewpoint on OS treatment.

Long non-coding RNA MALAT1 silencing elevates microRNA-26a-5p to ameliorate myocardial injury in sepsis by reducing regulator of calcineurin 2

ObjectiveSepsis is a leading cause of morbidity and mortality after surgery. We aimed to explore the role of long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) sponging microRNA-26a-5p in sepsis-induced myocardial injury by regulating regulator of calcineurin 2 (Rcan2). MethodsHL-1 cells were incubated with lipopolysaccharide (LPS) to induce in vitro cardiomyocyte injury models, which were then treated with silenced MALAT1 vector, miR-26a-5p mimic or Rcan2 overexpression vector. Next, inflammatory factor level and apoptosis of cells were determined. The in vivo mouse models were constructed by intraperitoneal injection of LPS. The modeled mice were injected with relative oligonucleotides and the pathology, apoptosis, and inflammation in mouse myocardial tissues were assessed. Expression of MALAT1, miR-26a-5p and Rcan2 in vivo and in vitro was evaluated. ResultsMALAT1 and Rcan2 were upregulated while miR-26a-5p was downregulated in LPS-treated HL-1 cells and mice. MALAT1 silencing or miR-26a-5p upregulation suppressed LPS-induced inflammation and apoptosis of cardiomyocytes in cellular and animal models. These effects of elevated miR-26a-5p could be reversed by upregulating Rcan2, and MALAT1 knockdown-induced ameliorative impacts could be reversed by miR-26a-5p downregulation. ConclusionMALAT1 silencing elevated miR-26a-5p to ameliorate LPS-induced myocardial injury by reducing Rcan2. Our research may provide novel biomarkers for the treatment of sepsis.

Associations between LncRNA MALAT1 Polymorphisms and Lymph Node Metastasis in Prostate Cancer.

Current evidence elucidates that long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) could regulate genetic expression and play a crucial role in both the diagnosis and prognosis of prostate cancer. Single-nucleotide polymorphisms (SNPs) of MALAT1 could alter the oncogenesis in various cancers. However, the associations between MALAT1 SNPs and prostate cancer have barely been investigated to date. This study included 579 patients with prostate cancer who received robotic-assisted radical prostatectomy at Taichung Veterans General Hospital from 2012 to 2017. Three SNPs of MALAT1 were analyzed to identify the impacts of SNPs on the clinicopathologic features in Taiwanese prostate cancer. Our results show that patients with a polymorphic G allele at rs619586 had a significantly higher risk of being in an advanced Gleason grade group (AOR: 1.764; 95% CI: 1.011–3.077; p = 0.046). Moreover, individuals with at least one polymorphic A allele at MALAT1 rs1194338 in the PSA >10 ng/mL group were positively associated with node-positive prostate cancer. In conclusion, MALAT1 SNPs are significantly associated with the susceptibility to both advanced Gleason grade and nodal metastasis in prostate cancer. The presence of MALAT1 SNPs rs619586 and rs1194338 seems to enhance oncogenesis in prostate cancer.

Long Noncoding RNA Metastasis-Associated Lung Adenocarcinoma Transcript 1 Promotes the Osteoblast Differentiation of Human Bone Marrow-Derived Mesenchymal Stem Cells by Targeting the microRNA-96/Osterix Axis.

To investigate whether and how the long noncoding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) sponges microRNA-96 (miR-96) to achieve the osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (hBMSCs). Protein levels were detected by Western blot. Mineralized bone matrix formation was studied by alizarin red staining. Metastasis-associated lung adenocarcinoma transcript 1, miR-96, and osteogenesis-related Messenger RNA expression was assessed by Quantitative Real-time Polymerase Chain Reaction (qRT-PCR). The interactions between miR-96 and osterix (Osx), MALAT1, and miR-96 were determined by luciferase reporter assay. The expression of MALAT1 was upregulated whereas that of miR-96 was downregulated in osteogenic hBMSCs. In addition, the expression of MALAT1 significantly decreased whereas that of miR-96 increased in the hBMSCs of osteoporosis (OP) patients. qRT-PCR and alizarin red staining assays showed that MALAT1 silencing or miR-96 overexpression inhibits hBMSC osteogenic differentiation and vice versa. overexpression of miR-96 reversed the promotive effect of MALAT1 on the osteogenic differentiation of hBMSCs. Dual luciferase report assay verified that miR-96 is a regulatory target of MALAT1 and that Osx is a gene target of miR-96. Taken together, the results demonstrate that MALAT1 promotes the osteogenic differentiation of hBMSCs by regulating the miR-96/Osx axis. Our study provides novel mechanistic insights into the critical role of lncRNA MALAT1 as a microRNA sponge in OP patients and sheds new light on lncRNA-directed diagnostics and therapeutics in OP.

MALAT1: A Pivotal lncRNA in the Phenotypic Switch of Gastric Smooth Muscle Cells via the Targeting of the miR-449a/DLL1 Axis in Diabetic Gastroparesis.

Diabetic gastroparesis (DGP) is a common complication of diabetes mellitus (DM). Our previous study suggested that the expression of the long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is closely related to DGP. However, the role of MALAT1 in DGP pathogenesis remains unclear. Here, we aim to characterize the role of MALAT1 in DGP. First, we analyzed the lncRNA expression profiles through lncRNA sequencing. Next, we detected MALAT1 expression in the stomach tissues of DGP model mice and diabetic patients. Then, we investigated the role and mechanisms of MALAT1 in the proliferation, migration, phenotypic switch, and carbachol-induced intracellular Ca2+ changes in human gastric smooth muscle cells (HGSMCs) under high glucose (HG) conditions, using short hairpin RNA technology, RNA immunoprecipitation, and dual-luciferase reporter assays. We show that MALAT1 expression was upregulated in the gastric tissues of DGP model mice, the adjacent healthy tissues collected from diabetic gastric cancer patients with DGP symptoms, and in HGSMCs cultured under HG conditions. Functionally, MALAT1 knockdown in vitro impacted the viability, proliferation, migration and promoted the phenotypic switch of HGSMCs under HG conditions. Additionally, we show that MALAT1 sponged miR-449a, regulating Delta-like ligand 1 (DLL1) expression in HGSMCs; any disturbance of the MALAT1/miR-449a/DLL1 pathway affects the proliferation, migration, phenotypic switch, and carbachol-induced Ca2+ transient signals in HGSMCs under HG conditions. Collectively, our data highlight a novel regulatory signaling pathway, the MALAT1/miR-449a/DLL1 axis, in the context of DGP.

Mechanism of tumor‑derived extracellular vesicles in regulating renal cell carcinoma progression by the delivery of MALAT1.

Renal cell carcinoma (RCC) is a major healthcare burden globally. Tumor-derived extracellular vesicles (EVs) contribute to the formation of a pro-metastatic microenvironment. In the present study, we explored the role and mechanism of RCC cell 786-O-derived EVs (786-O-EVs) in RCC. First, 786-O-EVs were extracted and identified, and EV internalization of RCC cells was observed. RCC cell malignant behaviors and long noncoding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) expression patterns were detected before and after 786-O-EV treatment. MALAT1 was intervened to evaluate RCC cell behaviors. The downstream mechanism involving MALAT1 was predicted. In addition, the relationship among MALAT1, transcription factor CP2 like 1 (TFCP2L1) and ETS proto-oncogene 1, transcription factor (ETS1) was analyzed. TFCP2L1 expression patterns were measured after 786-O-EV exposure. Tumor xenograft formation assay and lung metastasis model were adopted to verify the role of 786-O-EVs in vivo in RCC. It was found that 786-O-EVs could be internalized by RCC cells. 786-O-EVs promoted RCC cell malignant behaviors, accompanied by elevated MALAT1 expression levels. The 786-O-EVs with MALAT1 knockdown attenuated the promotive effect of sole 786-O-EVs on RCC cells. MALAT1 located ETS1 in the TFCP2L1 promoter and negatively regulated TFCP2L1, and ETS1 protein could specifically bind to MALAT1. 786-O-EVs enhanced the binding of ETS1 and the TFCP2L1 promoter and decreased TFCP2L1 expression. In vivo, 786-O-EVs promoted tumor growth and RCC lung metastasis, which was suppressed following inhibition of MALAT1. Our findings indicated that 786-O-EVs promoted RCC invasion and metastasis by transporting MALAT1 to promote the binding of transcription factor ETS1 and TFCP2L1 promoter.

Propofol attenuates renal ischemia/reperfusion injury by regulating the MALAT1/miR-126-5p axis.

Propofol (PPF) plays a protective role in ischemia-reperfusion (I/R) in multiple organs, including renal ischemia-reperfusion injury (RIRI). The present study aimed to investigate the underlying mechanisms by which PPF exerts its protective functions in RIRI. BALB/c mice were employed for the construction of RIRI animal model. PPF pre-treatment was carried out before I/R. An in vitro I/R model was established with HK-2 cells after hypoxia/reoxygenation (H/R) culture, and PPF was utilized to treat the cells before H/R. A quantitative-polymerase chain reaction (qPCR) was conducted to detect long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) and miR-126-5p expression levels. Flow cytometry was adopted to detect the apoptosis of HK-2 cells. Bioinformatics analysis, qPCR, a luciferase reporter gene experiment and a RNA immunoprecipitation experiment were used to determine the regulatory relationship between MALAT1 and miR-126-5p. The expression level of vascular endothelial growth factor A (VEGFA) was examined by western blotting. MALAT1 expression was augmented and miR-126-5p was decreased in RIRI models. PPF pre-treatment remarkably reduced creatinine and urea nitrogen levels in the serum of BALB/c mice with RIRI, and diminished the apoptosis of HK-2 cells treated with H/R. In addition, PPF pre-treatment markedly restrained the expression of MALAT1 in both in vivo and in vitro models and up-regulated miR-126-5p expression. MALAT1 could adsorb miR-126-5p to repress it and up-regulate VEGFA. MALAT1 overexpression reversed the protective effects of PPF on RIRI. PPF protects the kidney against RIRI by inhibiting MALAT1 and up-regulating miR-126-5p expression, as well as indirectly inhibiting the expression of VEGFA.

LncRNA MALAT1 regulated ATAD2 to facilitate retinoblastoma progression via miR-655-3p.

Long noncoding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) was reported as an oncogene in many tumors including retinoblastoma (RB). This research mainly focused on the functions and mechanism of MALAT1 in RB. MALAT1 was upregulated in RB tissues and cells, and it served as a competing endogenous RNA (ceRNA) and inhibited miRNA-655-3p (miR-655-3p) expression, which eventually regulated the expression of miR-655-3p downstream target ATPase Family AAA Domain Containing 2 (ATAD2). The level of ATAD2 significantly increased, while that of miR-655-3p remarkably decreased in RB tissues and cells. MALAT1 depletion inhibited cell proliferation, metastasis, and epithelial–mesenchymal transition (EMT), but promoted apoptosis in vitro and blocked xenograft tumor growth in vivo. MALAT1 exerted its oncogenic functions in RB by regulating miR-655-3p/ATAD2 axis.

Long Noncoding RNA MALAT1 Regulates the Progression of Atherosclerosis by miR-330-5p/NF-κB Signal Pathway.

Long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) was reported to be related to atherosclerosis (AS) progression. However, the underlying mechanism of MALAT1 in AS remains unknown. Quantitative real-time polymerase chain reaction was performed to detect the expression of MALAT1 and miR-330-5p. Western blot was applied to assess the protein levels of cluster of differentiation 36, interleukin-1β, interleukin-6 and tumor necrosis factor-α, phosphorylation of nuclear factor kappa-B inhibitor alpha and phosphorylation of p65. Flow cytometry assay, cell counting kit 8 assay, triglyceride, and total cholesterol detection assays were used to detect the apoptosis, viability, and lipid indexes of THP-1 macrophages-derived foam cells. Online database starbasev2.0 was used to predict the binding sequences between MALAT1 and miR-330-5p and it was verified by dual-luciferase reporter system and RNA immunoprecipitation assay. Besides, an AS mice model was used to evaluate the effect of MALAT1 in vivo. As a result, MALAT1 was overexpressed, whereas miR-330-5p was downregulated in THP-1 macrophages-derived foam cells. MiR-330-5p was a target of MALAT1. MALAT1 depletion inhibited cell formation, apoptosis, and inflammation in THP-1 macrophages-derived foam cells. Besides, MALAT1 overexpression promoted the inflammation in AS mice model, which promoted the pathogenesis of AS. Furthermore, miR-330-5p regulated the nuclear factor kappa light chain enhancer of activated B cells (NF-κB) pathway in THP-1 macrophages-derived foam cells. Moreover, MALAT1 regulated NF-κB signal pathway to mediate the pathogenesis of AS by sponging miR-330-5p. MALAT1 sponges miR-330-5p to activate NF-κB signal pathway in THP-1 macrophages-derived foam cells. This finding may provide a novel biomarker for AS diagnosis.

MascRNA and its parent lncRNA MALAT1 promote proliferation and metastasis of hepatocellular carcinoma cells by activating ERK/MAPK signaling pathway

MALAT1-associated small cytoplasmic RNA (mascRNA) is a cytoplasmic tRNA-like small RNA derived from nucleus-located long noncoding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1). While MALAT1 was extensively studied and was found to function in multiple cellular processes, including tumorigenesis and tumor progression, the role of mascRNA was largely unknown. Here we show that mascRNA is upregulated in multiple cancer cell lines and hepatocellular carcinoma (HCC) clinical samples. Using HCC cells as model, we found that mascRNA and its parent lncRNA MALAT1 can both promote cell proliferation, migration, and invasion in vitro. Correspondingly, both of them can enhance the tumor growth in mice subcutaneous tumor model and can promote metastasis by tail intravenous injection of HCC cells. Furthermore, we revealed that mascRNA and MALAT1 can both activate ERK/MAPK signaling pathway, which regulates metastasis-related genes and may contribute to the aggressive phenotype of HCC cells. Our results indicate a coordination in function and mechanism of mascRNA and MALAT1 during development and progress of HCC, and provide a paradigm for deciphering tRNA-like structures and their parent transcripts in mammalian cells.

Long non\u2010coding RNA MALAT1 regulates cell proliferation and apoptosis via miR-135b-5p/GPNMB axis in Parkinson\u2019s disease cell model

BackgroundsParkinson’s disease (PD) is a common age-related neurodegenerative disorder worldwide. This research aimed to investigate the effects and mechanism underlying long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in PD.MethodsSK-N-SH and SK-N-BE cells were treated with MPP+ to establish the MPP+-stimulated cell model of PD, and MALAT1 expression was determined. Then, the effects of MALAT1 depletion on cell proliferation and apoptosis were determined in the MPP+-stimulated cell model of PD. Besides, the correlations between microRNA-135b-5p (miR-135b-5p) and MALAT1 or glycoprotein nonmetastatic melanoma protein B (GPNMB) in MPP+-stimulated cell model of PD were explored.ResultsMALAT1 was increasingly expressed and downregulation of MALAT1 promoted cell proliferation while inhibited apoptosis in MPP+-stimulated cells. Besides, miR-135b-5p was a target of MALAT1 and directly targeted to GPNMB. Further investigation indicated that suppression of MALAT1 regulated cell proliferation and apoptosis by miR-135b-5p/GPNMB axis.ConclusionOur findings reveal that MALAT1/miR-135b-5p/GPNMB axis regulated cell proliferation and apoptosis in MPP+-stimulated cell model of PD, providing a potential biomarker and therapeutic target for PD.

Long non‐coding RNA MALAT1 and its target microRNA‐125b associate with disease risk, severity, and major adverse cardiovascular event of coronary heart disease

BackgroundThis study aimed to explore the correlation of long non‐coding RNA metastasis‐associated lung adenocarcinoma transcript 1 (lncRNA MALAT1) with microRNA (miR)‐125b and further investigated their associations with disease risk, severity, and prognosis of coronary heart disease (CHD).MethodsTotally, 230 patients who underwent diagnostic coronary angiography were recruited; meanwhile, 140 of them were diagnosed as CHD and the remaining 90 non‐CHD patients served as controls. Plasma sample was collected from each participant for lncRNA MALAT1 and miR‐125b mRNA expression detection by reverse transcription‐quantitative polymerase chain reaction. The extent of coronary stenosis was evaluated by the Gensini score, and major adverse cardiovascular event (MACE) occurrence during the follow‐up was documented in CHD patients.ResultsLong non‐coding RNA metastasis‐associated lung adenocarcinoma transcript 1 relative expression was increased, but miR‐125b relative expression was decreased in CHD patients compared with controls. ROC curve exhibited that lncRNA MALAT1 and miR‐125b were of good value in differentiating CHD patients from controls, and further logistic regression analysis verified their independent correlation with CHD risk. Furthermore, lncRNA MALAT1 presented a closely negative correlation with miR‐125b in CHD patients, while it presented a weakly negative association with miR‐125b in controls. In CHD patients, lncRNA MALAT1 was positively correlated with Gensini score, total cholesterol, low‐density lipoprotein cholesterol, C‐reactive protein, tumor necrosis factor α, interleukin (IL)‐1β, IL‐6, IL‐17, and accumulating MACE occurrence; reversely, miR‐125b presented a opposite trend.ConclusionLong non‐coding RNA metastasis‐associated lung adenocarcinoma transcript 1 might be associated with increased CHD risk, severity, and accumulating MACE incidence via negative interaction with miR‐125b, suggesting their possible clinical application as biomarkers in the CHD screening and surveillance.

Long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 correlates with microRNA-125b/microRNA-146a/microRNA-203 and predicts 2-year restenosis risk in coronary heart disease patients.

Aim: To investigate correlations of long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (lnc-MALAT1) and its target microRNAs with clinical features and restenosis risk in coronary heart disease (CHD) patients post drug-eluting stent-percutaneous coronary intervention(DES-PCI). Materials & methods: A total of274 CHD patients undergoing DES-PCI were enrolled, pre-operative plasma samples were obtained to detect lnc-MALAT1, miR-125b, miR-146a, miR-203 by RT-qPCR; 2-year restenosis was determined by quantitative coronary angiography. Results: Lnc-MALAT1 negatively correlated with miR-125b, miR-146a and miR-203. Furthermore, lnc-MALAT1, miR-125b, miR-146a and miR-203 correlated with diabetes mellitus, hyperuricemia, lesion properties, cholesterol, inflammation and cardiac function indexes. Additionally, lnc-MALAT1 was increased, while miR-125b and miR-146a were decreased in patients with 2-year restenosis than patients without 2-year restenosis; however, miR-203 did not differ. Conclusion: Lnc-MALAT1 and its target miRNAs might help manage restenosis risk in CHD patients post DES-PCI.

Aerobic exercise improves cardiac function in rats with chronic heart failure through inhibition of the long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1).

BackgroundTo explore the beneficial effects and underlying mechanisms of aerobic exercise on chronic heart failure (CHF).MethodsA CHF rat model was induced via left anterior descending coronary artery ligation. Four weeks post-surgery, CHF rats received aerobic exercise training over an 8-week period and cardiac function indexes including xxx were analyzed. To investigate the mechanisms involved in the aerobic exercise-induced benefits on CHF, overexpression of the long non-coding RNA MALAT1 was examined both in vivo and in vitro. Furthermore, the interaction between MALAT1 and the microRNA miR-150-5p and the downstream PI3K/Akt signaling pathway was investigated.ResultsCompared to the control group, the CHF rats showed evidence of left ventricular dysfunction including aggravated cardiac function indexes and lung to body weight ratio. The Masson staining demonstrated a significant degree of blue-stained fibrotic myocardial tissue in CHF rats compared to control rats. Furthermore, the levels of collagen I and collagen II were also markedly increased in CHF rats. Aerobic exercise improved cardiac function and left ventricular remodeling in rats with CHF. There was a significant reduction in the levels of the reactive oxygen species (ROS), inflammatory cytokines including TNF-α, IL-6, and IL-1β, and inflammatory mediums containing the matrix metalloproteinases (MMPs) MMP-2 and MMP-9. Moreover, CHF rats receiving aerobic exercise showed decreased myocardial apoptosis and increased expression of autophagy-related proteins including beclin-1 and LC3B-II. Overexpression of the lncRNA MALAT1 eliminated all the beneficial effects related to aerobic exercise in CHF rats. Subsequent investigations demonstrated that miR-150-5p expression was up-regulated in CHF-Tr rats and down-regulated in CHF-Tr-MALAT1 rats. Furthermore, the downstream PI3K/Akt signaling pathway was re-activated in CHF-Tr-MALAT1 rats. In vitro experiments revealed that overexpression of MALAT1 reduced the miR-150-5p levels, resulting in increased cellular apoptosis and less autophagy. In addition, overexpression of MALAT1 suppressed the downstream PI3K/Akt signaling pathway. Restoring miR-150-5p level with a miR-150-5p mimic decreased the cellular apoptosis and increased autophagy, and the downstream PI3K/Akt signaling pathway was re-activated.ConclusionsAerobic exercise improved cardiac function through inhibition of the lncRNA MALAT1 in CHF, and the potential mechanisms may be mediated via the miR-150-5p/PI3K/Akt signaling pathway.

Long Non-coding RNAMALAT1 Knockdown Alleviates Cerebral Ischemia/Reperfusion Injury of Rats Through Regulating the miR-375/PDE4D Axis.

Objectives: Cerebral ischemic/reperfusion injury (CI/RI) is the clinical manifestation of cerebral ischemic stroke, which severely affects the health and life of the patients. We aimed to investigate the regulatory mechanism of long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) on CI/RI in this study.Methods: The expression of lncRNA MALAT1 and miR-375 was detected by qRT-PCR. MTT was utilized to measure the viability of PC-12 cells. The levels of lactate dehydrogenase (LDH), superoxide dismutase (SOD), and reactive oxygen species (ROS) were detected by LDH assay, SOD assay, and ROS assay, respectively. The apoptosis rate of PC-12 cells was measured by flow cytometry analysis. Through enzyme-linked immunosorbent assay, the levels of NF-α, IL-1β, and IL-6 were determined. The interactions between miR-375 and MALAT1/PDE4D were predicted by Starbase/Targetscan software and verified by the dual-luciferase reporter assay. Western blot assay was performed to determine the protein expression of Bcl-2, Caspase-3, and PDE4D.Results: LncRNA MALAT1 expression was highly upregulated in the middle cerebral artery occlusion (MCAO)/reperfusion (R) model of rats. Both MALAT1 downregulation and miR-375 upregulation reversed the inhibitory effect of oxygen and glucose deprivation (OGD)/R on cell viability and the promoting effects on LDH level, cell apoptosis, and inflammatory factors levels. MALAT1 targeted miR-375, whereas miR-375 targeted PDE4D. Overexpression of miR-375 attenuated OGD/R-induced injury in PC-12 cells by targeting PDE4D. Both the low expression of miR-375 and high expression of PDE4D reversed the promoting effect of MALAT1 knockdown on SOD level and the inhibitory effects on ROS level, inflammatory factor levels, and cell apoptosis.Conclusion: Suppression of MALAT1 alleviates CI/RI of rats through regulating the miR-375/PDE4D axis. This study provides a possible therapeutic strategy for human CI/RI in clinic.

Suppression of lncRNA MALAT1 Reduces LPS- or IL-17A-Induced Inflammatory Response in Human Middle Ear Epithelial Cells via the NF-κB Signaling Pathway.

Otitis media (OM) is a common inflammatory disease of the middle ear cavity and mainly occurs in children. As a critical regulator of inflammation response, the nuclear factor kappa B (NF-κB) pathway has been found to play an essential role in the pathogenesis of various human diseases. The aim of this study was to explore the potential mechanism under the inflammatory response of human middle ear epithelial cells (HMEECs). We established in vitro models of OM by treating HMEECs with lipopolysaccharide (LPS) or interleukin 17A (IL-17A). Enzyme-linked immunosorbent assay and western blot analysis were used to measure the inflammatory response of HMEECs under LPS or IL-17A stimulation. The results revealed that the concentrations of proinflammatory cytokines (p < 0.001) and protein levels of mucin (MUC) (for MUC5AC, p = 0.002, p = 0.004; for MUC8, p = 0.004, p < 0.001) were significantly elevated by LPS or IL-17A stimulation in HMEECs. Moreover, we found that LPS or IL-17A treatment promoted the phosphorylation of IκBα (for p-IκBα, p = 0.018, p = 0.002; for IκBα, p = 0.238, p = 0.057) and the translocation of p65 from cytoplasm to nucleus in HMEECs (for nucleus p65, p = 0.01; for cytoplasm p65, p < 0.001). In addition, RT-qPCR analysis revealed that long noncoding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) was verified to be upregulated in LPS- or IL-17A-stimulated HMEECs (p < 0.001). Western blot analysis and immunofluorescence staining assay revealed that that MALAT1 knockdown significantly suppressed the activation of the NF-κB pathway by reducing phosphorylated IκBα levels and inhibiting the nuclear translocation of p65 (p < 0.001) in LPS- or IL-17A-stimulated HMEECs (for p-IκBα, p < 0.001; for IκBα, p = 0.242, p = 0.647). Silence of MALAT1 decreased the proinflammatory cytokine production and MUC protein levels (p < 0.001). Furthermore, rescue assays revealed that the increase of proinflammatory cytokine production (for TNF-α, p = 0.002, p = 0.015; for IL-1β, p < 0.001, p = 0.006; for IL-6, p = 0.002, p < 0.001) and MUC protein levels (for MUC5AC, p = 0.001, p < 0.001; for MUC8, p < 0.001, p = 0.001) induced by MALAT1 overexpression was neutralized by 4-N-[2-(4-phenoxyphenyl) ethyl] quinazoline-4, 6-diamine (QNZ) treatment in LPS- or IL-17A-stimulated HMEECs. In conclusion, MALAT1 promotes inflammatory response in LPS- or IL-17A- stimulated HMEECs via the NF-κB signaling pathway, which may provide a potential novel insight for the treatment of OM.

An Integrated Transcriptomics and Proteomics Analysis Implicates lncRNA MALAT1 in the Regulation of Lipid Metabolism

Long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is upregulated in various cancers, and its overexpression is associated with tumor growth and metastasis. MALAT1 has been recognized as a key player in the regulation of RNA splicing and transcription; however, the landscape of gene expression regulated by MALAT1 remains unclear. In this study, we employed an integrated transcriptomics and proteomics strategy to characterize the alterations in gene expression induced by MALAT1 knockdown in hepatocellular carcinoma (HCC) cells and identified 2662 differentially expressed transcripts and 1149 differentially expressed proteins. Interestingly, downregulation of MALAT1 reduced the abundances of multiple genes in the AMP-activated protein kinase (AMPK) signaling and biosynthesis of unsaturated fatty acids pathways. Further investigation showed that MALAT1 knockdown inhibited glucose uptake and lipogenesis by reducing the expression levels of these lipid metabolism related genes, which contributes to the oncogenic role of MALAT1 in tumor cell proliferation and invasion. This study uncovers the function of MALAT1 in the modulation of cancer lipid metabolism, reveals the underlying molecular mechanism, and further supports the potential therapeutic opportunities for targeting MALAT1 in HCC treatment.

Peripheral Blood-Based DNA Methylation of Long Non-Coding RNA H19 and Metastasis-Associated Lung Adenocarcinoma Transcript 1 Promoters are Potential Non-Invasive Biomarkers for Gastric Cancer Detection.

IntroductionThe early diagnosis and detection could greatly improve the clinical outcome of gastric cancer (GC) patients. However, the non-invasive biomarkers for GC detection remain to be identified.MethodWe used online databases (GEPIA, UALCAN, Kaplan-Meier plotter, TIMER, and MEXPRESS) to explore the association between H19 or metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) expression in tissues and the occurrence, development, prognosis, the levels of immune cell infiltration, and methylation of GC; the correlation between mRNA expression and DNA methylation levels of genes were also examined. Methylation levels of H19 or MALAT1 in peripheral blood were compared between 150 GC patients and 100 healthy controls (HCs). Predictive nomograms were constructed among female and male groups for GC diagnosis. The calibration curves, Hosmer–Lemeshow test, and decision curve analysis were also used to examine the nomograms’ predictive ability and clinical values.ResultsUsing multiple online databases, we found that the mRNA expressions of H19 and MALAT1 in tissues were related to the occurrence of GC, and such expressions were associated with immune cell infiltration of GC and negatively correlated with DNA methylation levels of H19 and MALAT1. H19 gene, H19C island, and MALAT1B island, as well as 20 CpG sites were hypermethylated in peripheral blood of GC patients compared with HCs; similar results were also found in female and male groups (P < .05 for all). The combination of H19c3, H19c4, MALAT1b12, and age, as well as the combination of H19b7, H19c1, H19c5, and age in the nomograms could distinguish GC patients from HCs in the female group and male group, respectively.ConclusionWe found statistically significant hypermethylation of H19 and MALAT1 promoters in GC patients, and meaningful sensitivity and specificity of MALAT1 and H19 methylation in discriminating GC and HCs were observed in both female and male groups, which indicates that the peripheral blood-based DNA methylation of H19 and MALAT1 could act as potential non-invasive biomarkers for the diagnosis of GC.

LncRNA-MALAT1/miRNA-204-5p/Smad4 Axis Regulates Epithelial–Mesenchymal Transition, Proliferation and Migration of Lens Epithelial Cells

ABSTRACT Purpose: Posterior capsular opacification (PCO), a common complication after cataract surgery, primarily originated from the epithelial–mesenchymal transition (EMT), proliferation, and migration of human lens epithelial cells (LECs). This study aimed to explore whether the long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1)/miR-204-5p/Smad4 axis are involved in EMT of LECs. Materials and methods LECs were cultured and induced with TGF-β2 (10 ng/mL). SiRNA against MALAT1 (Si‐MALAT1) was transfected into LECs to knockdown the expression of MALAT1. To overexpress or knockdown miR‐204-5p, miR-204-5p mimics (miR-204-5p mimics) and anti-miR-204-5p (miR-204-5p inhibitor) were transfected into LECs. We used RNA FISH to identify the location of MALAT1. RNA levels of MALAT1 and miR-204-5p were analyzed by RT-qPCR. Additionally, target protein levels of Smad4, epithelial differentiation and mesenchymal markers were analyzed with Western blot. We employed EdU Labeling to measured cell proliferation and performed Transwell Assay to analyze the cell migration. Dual-luciferase reporter assays in LECs were conducted to verify whether miRNA-204-5p was negatively regulated by MALAT1 and Smad4 was a direct target of miR-204-5p. Results The expression of MALAT1 was upregulated in PCO specimens. MALAT1 was overexpressed in TGF-β2 induced LECs, and the knockdown of MALAT1 could attenuate TGF-β2 induced EMT. Besides, the upregulation of MALAT1 was correlated with the downregulation of miR-204-5p and upregulation of Smad4. Importantly, MALAT1 was revealed to be located in the cytoplasm of LECs. Furthermore, luciferase reporter assays confirmed that MALAT1 could negatively regulate the expression of miR-204-5p and then regulate its direct target Smad4. Finally, the knockdown of MALAT1 could inhibit the EMT, proliferation, and migration of LECs; however, those can be reversed by anti-miR-204-5p. Conclusions Our findings reveal that MALAT1 may regulate EMT, proliferation, and migration of LECs as a ceRNA by “sponging” miR-204-5p and targeting Smad4, and serve as a promising therapeutic target in preventing PCO.

Vitamin D status influences cytokine production and MALAT1 expression from the PBMCs of patients with coronary artery disease and healthy controls.

This study aimed to investigate the long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (lncRNA MALAT1) expression and its role in cytokine production from peripheral blood mononuclear cells (PBMCs) in patients with coronary artery disease (CAD) and non-CAD participants (NCAD). Blood samples were taken from 15 patients with CAD and 15 NCAD individuals. The plasma was used for biochemical analyses. MALAT1 and CD36 expressions were evaluated in the isolated peripheral blood mononuclear cells (PBMCs) by real-time PCR. Furthermore, the levels of inflammatory cytokines e.g. interleukin (IL)-6, IL-10, and IL-22 were measured in the supernatants of the cultured PBMCs by flow cytometry. The levels of MALAT1 and CD36 were not significantly different between the CAD and NCAD groups. However, a lower level of MALAT1 and CD36 was observed in PBMCs of vitamin D deficient (<15 ng/ml) CAD and NCAD participants. Furthermore, the vitamin D deficient (<15 ng/ml) group showed a significantly higher plasma level of IL-6, IL-10, and IL-22 compared to the non-deficient (≥15 ng/ml) group. In addition, significant positive correlations were found between CD36, IL-22, and fasting blood sugar (FBS) with MALAT1. Given that in vitamin D deficient individuals a decreased level of MALAT1 was associated with CD36 expression and increased IL-22 production, vitamin D supplementation may play a role in reducing MALAT1/CD36/IL-22 mediated complications such as T2DM and CAD, especially in vitamin D deficiency.