The lncRNA-MALAT1/miR-330-3p Axis Promotes Growth and Metastasis of Gastric Cancer Through Regulation of Vascular Endothelial Growth Factor A: A Genetic and Cell Evaluation Study

SUMMARY: Overexpression of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in various tumor tissues and cell lines was found to promote tumor cell proliferation, migration, and invasion. However, the role of MALAT1 in gastric cancer (GC) is still unclear. We aimed to investigate the correlation between long-chain non-coding RNAs (lncRNAs), MALAT1, MicroRNAs (miRNA) and vascular endothelial growth factor A (VEGFA) in gastric cancer and to disclose underlying mechanism. The correlation between MALAT1 levels and clinical features was analyzed by bioinformatics data and human samples. The expression of MALAT1 was down regulated in AGS cells to detect the cell proliferation, migration, and invasion characteristics, as well as the effects on signal pathways. Furthermore, we validated the role of MALAT1/miR-330-3p axis in GC by dual luciferase reporter gene assays. Expression of MALAT1 was higher in cancer tissues than in para-cancerous tissues. The high MALAT1 level predicted malignancy and worse prognosis. Down-regulation of MALAT1 expression in AGS cells inhibited cell proliferation, migration, and invasion by targeting VEGFA. By dual luciferase reporter gene assay and miR-330-3p inhibitor treatment, we demonstrate that MALAT1 sponged miR-330-3p in GC, leading to VEGFA upregulation and activation of the mTOR signaling pathway. The MALAT1/miR-330-3p axis regulates VEGFA through the mTOR signaling pathway and promotes the growth and metastasis of gastric cancer.

Se descubrió que la sobreexpresión del transcrito 1 de adenocarcinoma de pulmón asociado a metástasis (MALAT1) en varios tejidos tumorales y líneas celulares promueve la proliferación, migración e invasión de células tumorales. Sin embargo, el papel de MALAT1 en el cáncer gástrico (CG) aún no está claro. Nuestro objetivo fue investigar la correlación entre los ARN no codificantes de cadena larga (lncRNA), MALAT1, los microARN (miARN) y el factor de crecimiento endotelial vascular A (VEGFA) en el cáncer gástrico y revelar el mecanismo subyacente. La correlación entre los niveles de MALAT1 y las características clínicas se analizó mediante datos bioinformáticos y muestras humanas. La expresión de MALAT1 se reguló negativamente en las células AGS para detectar las características de proliferación, migración e invasión celular, así como los efectos sobre las vías de señales. Además, validamos el papel del eje MALAT1/miR- 330-3p en GC mediante ensayos de genes indicadores de luciferasa dual. La expresión de MALAT1 fue mayor en tejidos cancerosos que en tejidos paracancerosos. El alto nivel de MALAT1 predijo malignidad y peor pronóstico. La regulación negativa de la expresión de MALAT1 en células AGS inhibió la proliferación, migración e invasión celular al apuntar a VEGFA. Mediante un ensayo de gen indicador de luciferasa dual y un tratamiento con inhibidor de miR-330-3p, demostramos que MALAT1 esponjaba miR-330-3p en GC, lo que lleva a la regulación positiva de VEGFA y la activación de la vía de señalización mTOR. El eje MALAT1/miR-330-3p regula VEGFA a través de la vía de señalización mTOR y promueve el crecimiento y la metástasis del cáncer gástrico.

Effect and Potential Mechanism of Inhibition of Long Non-coding RNA MALAT1 on Glycolipipotoxicity-induced Endothelial Cell Dysfunction / 中国循环杂志

Objectives:To investigate the effect of inhibition of long non-coding RNA(lnc RNA)in human metastasis associated lung adenocarcinoma transcript 1(MALAT1)on glycolipitoxicity-induced human umbilical vein endothelial cell dysfunction. Methods:Human umbilical vein endothelial cells were treated with glucose and palmitic acid in vitro to establish the glycolipitoxic endothelial cell models.Following groups were examined:control group,high-glucose and high-fat group,high-glucose and high-fat + non-targeting RAN control group,high-glucose and high-lipid+MALAT1 siRNA group,and high-glucose and high-lipid+MAPK1 siRNA group.RT-qPCR was used to detect the mRNA expression of MALAT1 and MAPK1.Western blot was used to detect the expression levels of autophagy,mitochondrial fusion division,apoptosis,and pathway-related proteins.Immunofluorescence confocal localization was used to detect the fluorescence colocalization of autophagy and lysosome-related proteins.The number of autophagolysosomes in endothelial cells was observed by transmission electron microscopy.Mitochondrial probe staining was used to detect mitochondrial morphology,immunofluorescence was used to detect intracellular reactive oxygen species(ROS)production,flow cytometry was used to detect the apoptosis of cells in each group,cell proliferation and scratch assays were used to detect the proliferation and migration ability of cells in different groups at different time points.The angiogenesis was quantified by counting the number of new blood vessels in each group. Results:Compared with the control group,the expression of lncRNA MALAT1 mRNA and the expression of phosphorylated mito-activated protein kinase 1(p-MAPK1)were upregulated(both P＜0.05)and the expression of phosphorylated mammalian target protein(p-mTOR)was downregulated in the high-glucose and high-fat group and the high-sugar and high-fat control group(all P＜0.01).Compared with the high-glucose and high-fat non-targeting RNA control group,the expressions of microtubule-associated protein 1A/1B-light chain 3(LC3)and p62 were downregulated(P＜0.01,P＜0.05),LC3 and lysosome-associated membrane protein 2(LAMP2)protein co-localized positive fluorescence particles were increased(both P＜0.01),number of lysosomes were decreased,the expression of ROS was decreased(P＜0.01),the expression level of mitochondrial fusion protein optic nerve atrophin 1(OPA1)was increased(P＜0.05),the expressions of cleaved caspase-3 and BCL-2-related X protein(BAX)were decreased and BCL-2 was increased(all P＜0.05),cell proliferation,migration,and tube-forming ability were increased(all P＜0.01),and the expression of p-MAPK1 was decreased(P＜0.05)and p-mTOR expression was increased(both P＜0.05)in the high-glucose and high-lipid+si-MALAT1 group.Compared with the high-glucose and high-fat non-targeting RNA control group,the expression of p-MAPK1 in endothelial cells was decreased and the expression of p-mTOR was increased in the high-glucose and high-lipid+si-MAPK1 group(both P＜0.01). Conclusions:Inhibition of lncRNA MALAT1 expression can reduce the level of mitophagy in glycolipidotoxic environments,reduce apoptosis of endothelial cells and improve endothelial cell function,which may be related to the regulation of MAPK1/mTOR signaling pathway.

Research on the lncRNA MALAT1 promoting the proliferation, migration and angiogenesis of retinal vascular endothelial cells in diabetic retinopathy through the molecular axis of miR-124-3p/SOX7 / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the effect of lncRNA MALAT1 on the proliferation, migration and angiogenesis of retinal vascular endothelial cells and its molecular mechanism.METHODS: The expression levels of lncRNA MALAT1 in plasma of normal control group, diabetic without retinopathy group and diabetic retinopathy group were detected by qPCR and the effect of glucose culture on the expression levels of lncRNA MALAT1 were detected by qPCR too. The expression level of miR-124-3p was detected by qRT-PCR; Western blotting was used to detect the expression level of SOX7; The targeting relationship between lncRNA MALAT1 and miR-124-3p, miR-124-3p and SOX7 were detected by the dual-luciferase reporter system; CCK-8 assay was used to detect cell proliferation activity; Transwell assay was used to detect the migration ability of cells; Angiogenesis of hRMECs cells was measured by in vitro tube formation assay.RESULTS:The expression level of lncRNA MALAT1 in plasma of diabetic retinopathy patients was significantly higher than that of diabetic without retinopathy group and normal control group(P<0.001). In vitro glucose culture significantly promoted the expression of lncRNA MALAT1 in hRMECs cells, as well as the proliferation, migration and angiogenesis of hRMECs cells(all P<0.05). Knockdown of lncRNA MALAT1 significantly inhibited the proliferation, migration and tubule formation of hRMECs cells(all P<0.05). Dual-luciferase reporter gene assay showed that lncRNA MALAT1 targeted with miR-124-3p, and miR-124-3p targeted with SOX7. Overexpression of miR-124-3p significantly inhibited the proliferation, migration and tubule formation of hRMECs cells(all P<0.05). Overexpression of lncRNA MALAT1+miR-124-3p, miR-124-3p+SOX7, and knockdown of lncRNA MALAT1+overexpression of SOX7 all significantly eliminated the inhibitory effect of hRMECs cells(all P<0.05).CONCLUSION: lncRNA MALAT1 promote the proliferation, migration and angiogenesis of retinal endothelial cells in diabetic retinopathy by down-regulating the negative regulation of miR-124-3p on SOX7. Therefore, abnormal upregulation of lncRNA MALAT1 in patients with diabetic retinopathy is a potential biomarker.

Association of circulating long non-coding RNA MALAT1 in diagnosis, disease surveillance, and prognosis of acute ischemic stroke

We aimed to investigate the association of long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (lnc-MALAT1) with acute ischemic stroke (AIS), and its association with disease severity, inflammation, and recurrence-free survival (RFS) in AIS patients. One hundred and twenty AIS patients and 120 controls were recruited. Venous blood samples from AIS patients (within 24 h after symptoms onset) and controls (at entry to study) were collected to detect plasma lnc-MALAT1 expression by real-time quantitative polymerase chain reaction. AIS severity was assessed by the National Institutes of Health Stroke Scale (NIHSS) score. Plasma concentrations of inflammation factors (including C-reactive protein (CRP), tumor necrosis factor α (TNF-α), interleukin (IL)-6, IL-8, IL-10, IL-17, and IL-22) were measured and RFS was calculated. lnc-MALAT1 expression was decreased in AIS patients compared to controls, and it had a close correlation with AIS (AUC=0.791, 95% CI: 0.735-0.846). For disease condition, lnc-MALAT1 expression negatively correlated with NIHSS score and pro-inflammatory factor expression (including CRP, TNF-α, IL-6, IL-8, and IL-22), while it positively correlated with anti-inflammatory factor IL-10 expression. Furthermore, lnc-MALAT1 expression was elevated in AIS patients with diabetes. For prognosis, no statistical correlation of lnc-MALAT1 expression with RFS was found, while a trend for longer RFS was observed in patients with lnc-MALAT1 high expression compared to those with lnc-MALAT1 low expression.

MALAT1 upregulates SMYD3 by competition with miR-124 and promotes proliferation and migration of breast cancer cells / 中国药科大学学报

@#To investigate whether lncRNA MALAT1 affects the migration and proliferation of breast cancer cells through the regulation with histone methyltransferase SMYD3, the endogenous MALAT1 in the MCF-7 and MDA-MB-231 breast cancer cells were knocked down by siRNA, and then the migration and proliferation of cells were detected by wound healing migration and MTT assay. The effects of si-MALAT1 on the mRNA and protein levels of miRNA-124, SMYD3 and its downstream genes were detected by Real time PCR and Western blot. The results showed that siRNA-targeted knockdown of MALAT1 reduced the migration and proliferation of breast cancer cells, and inhibited the transcriptional expression of SMYD3 and its downstream genes, including N-cadherin, MYL9, MMP9 and CYR61, and up-regulated miR-124. Overexpression of miR-124 reduced the expression of SMYD3 in breast cancer cells, and knockdown of MALAT1 attenuated the promotion of SMYD3 protein expression by miR-124 inhibitors. In addition, SMYD3 overexpression activated MALAT1 transcription, whereas siRNA interference with SMYD3 downregulated MALAT1. These results indicate that LncRNA MALAT1 acted as a competing endogenous RNA(ceRNA)of miR-124 to regulate expression of SMYD3 in breast cancer cells, and SMYD3 can activate the transcription of MALAT1, which will affect the proliferation and migration of breast cancer cells.

Curcumin combining with si-MALAT1 inhibits the invasion and migration of colon cancer SW480 cells

To study the effect of small interfering RNA targeting metastasis-associated lung adenocarcinoma transcript1 (si-MALAT1) combining with curcumin on the invasion and migration abilities of human colon cancer SW480 cells, and to explore the involved molecular mechanism. The recombinant lentiviral vector expressing si-MALAT1 was constructed, and its titer was determined by gradient dilution method. The colon cancer SW480 cells with stable expression of si-MALAT1 was established, followed by treatment with curcumin at different concentrations. The effect of curcumin or si-MALAT1 alone and the combination of the two on the cell activity was detected by MTT assay. The cell invasion and migration abilities were detected by transwell and scratch-wound assay. The relative expression level of MALAT1 was detected by RT-qPCR. The protein expression was determined by Western blot analysis. The IC50 of curcumin alone was 77.69 mmol/L, which was 51.17 mol/L when combined with curcumin and random sequence. The IC50 of curcumin was 30.02 mmol/L when combined with si-MALAT1. The increased susceptibility multiples was 2.58. The wound healing rates were 30.9% and 67.5% after treatment with si-MALAT1 combined with curcumin for 24 hrs and 48 hrs, respectively. The numbers of invasion cells were 200±12, 162±13, 66±8, 53±4 and 16±3 after treatment with si-MALAT1 combined with curcumin for 48 hrs. The relative expression level of lncRNA-MALAT1 in the curcumin group was 68%, and the relative expression level of lncRNA-MALAT1 in si-MALAT1group was 56%, and that for the combination treatment group was about 21%. The protein expression levels of β- catenin, c-myc and cyclinD1 were significantly down-regulated upon treatment with certain concentration of si-MALAT1 alone or combined with curcumin.si-MALAT1 could significantly inhibit the invasion and migration of SW480 cells by enhancing the sensitivity of SW480 cells to curcumin. The mechanism involved mignt be related to the down-regulation of β-catenin, c-myc and cyclinD1 proteins.

LncRNA MALAT-1 regulates expression of miR-205 and affects growth and migration of non-small cell lung cancer cells / 中国免疫学杂志

Objective:To investigate the relationship between LncRNA MALAT-1 and miR-205 in non-small cell lung cancer and the mechanism of biological behavior in lung cancer cells.Methods: The expression of LncRNA MALAT-1 in different non-small cell lung cancer was detected by qPCR.The interaction between MALAT-1 and miR-205 was detected by double luciferase reporter gene.Transwell invasion assay and scratch test were used to detect the changes of invasion and migration abilities of lung cancer cells after silencing MALAT-1 and the recovery the abilities after inhibition of miR-205 expression.The tumor volume and quality of lung cancer cells were detected by subcutaneous tumor formation in nude mice after silencing MALAT-1.Results:Compared with other lung cancer cell lines,the expression of MALAT-1 was the highest and the expression level of miR-205 was the lowest in A549 cells.The double luciferase assay confirmed that MALAT-1 could specifically bind to 3′UTR of miR-205,and could regulate the expression and activity of miR-205.Inhibition of MALAT-1 expression could reduce the migration and invasion of lung cancer cells;while inhibiting the expression of miR-205 level,the migration and invasion of lung cancer cells could recovery.The tumor volume and quality of lung cancer cells were reduced after silencing MALAT-1 in subcutaneous tumorigenesis of nude mice.Conclusion: MALAT-1 can regulate the expression of miR-205 and affect the invasion and migration of lung cancer cell line A549.