LncRNA MAGI2-AS3 promotes fracture healing through downregulation of miR-223-3p.

BACKGROUND: Long non-coding RNAs (LncRNAs) are recognized as a pivotal element in the processes of fracture healing and the osteogenic differentiation of stem cells. This study investigated the molecular mechanism and regulatory significance of lncRNA MAGI2-AS3 (MAGI2-AS3) in fracture healing. METHODS: Serum levels of MAGI2-AS3 in patients with normal and delayed fracture healing were verified by RT-qPCR assays. The predictive efficacy of MAGI2-AS3 for delayed fracture healing was analyzed by ROC curve. Osteogenic markers were quantified by RT-qPCR assays. MC3T3-E1 cell viability was detected using CCK-8 assay, and flow cytometry was utilized to measure cell apoptosis. The dual-luciferase reporter gene assay was used to determine the targeted binding between MAGI2-AS3 and miR-223-3p. RESULTS: Serum MAGI2-AS3 expression was decreased in patients with delayed fracture healing compared with patients with normal healing. Elevated MAGI2-AS3 resulted in an upregulation of the proliferative capacity of MC3T3-E1 cells and a decrease in mortality, along with increased levels of both osteogenic markers. However, after transfection silencing MAGI2-AS3, the trend was reversed. Additionally, miR-223-3p was the downstream target of MAGI2-AS3 and was controlled by MAGI2-AS3. miR-223-3p mimic reversed the promoting effects of MAGI2-AS3 overexpression on osteogenic marker levels and cell growth, and induced cell apoptosis. CONCLUSION: The upregulation of MAGI2-AS3 may expedite the healing of fracture patients by targeting miR-223-3p, offering a novel biomarker for diagnosing patients with delayed healing.

BMSC derived EVs inhibit colorectal Cancer progression by transporting MAGI2-AS3 or something similar.

In this study, we investigated the molecular mechanisms underlying the impact of extracellular vesicles (EVs) derived from bone marrow stromal cells (BMSCs) on colorectal cancer (CRC) development. The focus was on the role of MAGI2-AS3, delivered by BMSC-EVs, in regulating USP6NL DNA methylation-mediated MYC protein translation modification to promote CDK2 downregulation. Utilizing bioinformatics analysis, we identified significant enrichment of MAGI2-AS3 related to copper-induced cell death in CRC. In vitro experiments demonstrated the downregulation of MAGI2-AS3 in CRC cells, and BMSC-EVs were found to deliver MAGI2-AS3 to inhibit CRC cell proliferation, migration, and invasion. Further exploration revealed that MAGI2-AS3 suppressed MYC protein translation modification by regulating USP6NL DNA methylation, leading to CDK2 downregulation and prevention of colorectal cancer. Overexpression of MYC reversed the functional effects of BMSC-EVs-MAGI2-AS3. In vivo experiments validated the inhibitory impact of BMSC-EVs-MAGI2-AS3 on CRC tumorigenicity by promoting CDK2 downregulation through USP6NL DNA methylation-mediated MYC protein translation modification. Overall, BMSC-EVs-MAGI2-AS3 may serve as a potential intervention to prevent CRC occurrence by modulating key molecular pathways.

Long non-coding RNAs PTENP1, GNG12-AS1, MAGI2-AS3 and MEG3 as tumor suppressors in breast cancer and their associations with clinicopathological parameters.

BACKGROUND: Breast cancer is the most commonly occurring cancer worldwide and is the main cause of death from cancer in women. Novel biomarkers are highly warranted for this disease. OBJECTIVE: Evaluation of novel long non-coding RNAs biomarkers for breast cancer. METHODS: The study comprised the analysis of the expression of 71 candidate lncRNAs via screening, six of which (four underexpressed, two overexpressed) were validated and analyzed by qPCR in tumor tissues associated with NST breast carcinomas, compared with the benign samples and with respect to their clinicopathological characteristics. RESULTS: The results indicated the tumor suppressor roles of PTENP1, GNG12-AS1, MEG3 and MAGI2-AS3. Low levels of both PTENP1 and GNG12-AS1 were associated with worsened progression-free and overall survival rates. The reduced expression of GNG12-AS1 was linked to the advanced stage. A higher grade was associated with the lower expression of PTENP1, GNG12-AS1 and MAGI2-AS3. Reduced levels of both MEG3 and PTENP1 were linked to Ki-67 positivity. The NRSN2-AS1 and UCA1 lncRNAs were overexpressed; higher levels of UCA1 were associated with multifocality. CONCLUSIONS: The results suggest that the investigated lncRNAs may play important roles in breast cancer and comprise a potential factor that should be further evaluated in clinical studies.

LncRNA MAGI2-AS3 inhibites tumor progression by up-regulating STAM via interacting with miR-142-3p in clear cell renal cell carcinoma.

Revealing the role of non-coding RNAs (ncRNAs) in inducing dysregulated pathological responses to external signals may identify therapeutic targets for inhibiting the progression of clear cell renal cell carcinoma (ccRCC). Non-coding RNAs belong to a class of RNA molecules that do not encode proteins but possess diverse biological functions, playing essential roles in the occurrence and development of metastatic and proliferative tumors. To investigate the impact of the upstream interaction between miR-142-3p and lncRNA MAGI2-AS3 on the tumor-suppressive activity of the STAM gene, we firstly conducted bioinformatics analysis to predict the upstream miRNAs of STAM and the upstream lncRNAs of the miRNAs through online databases (miRanda, miRDB, TargetScan, LncBase v2), which were further validated by the starBasev2.0 database. Subsequently, multiple experimental techniques were employed to validate these findings, including RT-qPCR, Western blotting, measurement of cellular functional activity, and luciferase reporter assays. Through these experimental methods, we provided compelling evidence regarding the role of miR-142-3p and MAGI2-AS3 in regulating STAM gene expression and functionality, revealing their potential significance in tumor suppression. Our research demonstrates the importance of the MAGI2-AS3/miR-142-3p/STAM signaling pathway axis in ccRCC. MAGI2-AS3 competes for binding with miR-142-3p, resulting in upregulated STAM gene expression. This upregulation inhibits tumor proliferation and metastasis in ccRCC cells. Conversely, overexpression of miR-142-3p or silencing of MAGI2-AS3 promotes tumor behavior, while downregulation of miR-142-3p inhibits the development of ccRCC. Targeting the MAGI2-AS3/miR-142-3p/STAM axis holds promise as a therapeutic strategy for ccRCC treatment.

MAGI2 ameliorates podocyte apoptosis of diabetic kidney disease through communication with TGF-ß-Smad3/nephrin pathway.

Podocytes, the key component of the glomerular filtration barrier (GFB), are gradually lost during the progression of diabetic kidney disease (DKD), severely compromising kidney functionality. The molecular mechanisms regulating the survival of podocytes in DKD are incompletely understood. Here, we show that membrane-associated guanylate kinase inverted 2 (MAGI2) is specifically expressed in renal podocytes, and promotes podocyte survival in DKD. We found that MAGI2 expression was downregulated in podocytes cultured with high-glucose in vitro, and in kidneys of db/db mice as well as DKD patients. Conversely, we found enforced expression of MAGI2 via AAV transduction protected podocytes from apoptosis, with concomitant improvement of renal functions. Mechanistically, we found that MAGI2 deficiency induced by high glucose levels activates TGF-ß signaling to decrease the expression of anti-apoptotic proteins. These results indicate that MAGI2 protects podocytes from cell death, and can be harnessed therapeutically to improve renal function in diabetic kidney disease.

Targeting MAGI2-AS3-modulated Akt-dependent ATP-binding cassette transporters as a possible strategy to reverse temozolomide resistance in temozolomide-resistant glioblastoma cells.

Drug resistance is a major impediment to the successful treatment of glioma. This study aimed to elucidate the effects and mechanisms of the long noncoding RNA membrane-associated guanylate kinase inverted-2 antisense RNA 3 (MAGI2-AS3) on temozolomide (TMZ) resistance in glioma cells. MAGI2-AS3 expression in TMZ-resistant glioblastoma (GBM) cells was analyzed using the Gene Expression Omnibus data set GSE113510 and quantitative real-time PCR (qRT-PCR). Cell viability and TMZ half-maximal inhibitory concentration values were determined using the MTT assay. Apoptosis and cell cycle distribution were evaluated using flow cytometry. The expression of multidrug resistance 1 (MDR1), ATP-binding cassette superfamily G member 2 (ABCG2), protein kinase B (Akt), and phosphorylated Akt was detected using qRT-PCR and/or western blot analysis. MAGI2-AS3 was expressed at low levels in TMZ-resistant GBM cells relative to that in their parental cells. MAGI2-AS3 re-expression alleviated TMZ resistance in TMZ-resistant GBM cells. MAGI2-AS3 overexpression also accelerated TMZ-induced apoptosis and G2/M phase arrest. Mechanistically, MAGI2-AS3 overexpression reduced MDR1 and ABCG2 expression and inhibited the Akt pathway, whereas Akt overexpression abrogated the reduction in MDR1 and ABCG2 expression induced by MAGI2-AS3. Moreover, activation of the Akt pathway inhibited the effects of MAGI2-AS3 on TMZ resistance. MAGI2-AS3 inhibited tumor growth and enhanced the suppressive effect of TMZ on glioma tumorigenesis in vivo. In conclusion, MAGI2-AS3 reverses TMZ resistance in glioma cells by inactivating the Akt pathway.

Role of MAGI2-AS3 in malignant and non-malignant disorders.

MAGI2 Antisense RNA 3 (MAGI2-AS3) is a long non-coding RNA (lncRNA) transcribed from a locus on 7q21.11. This lncRNA has been described to be abnormally expressed in a variety of malignancies in correlation with many clinical characteristics. Moreover, it might participate in the pathogenesis of congenital diaphragmatic hernia, Alzheimer's disease and intervertebral disc degeneration. Mechanistically, MAGI2-AS3 can serve as a molecular sponge for miR-142-3p, miR-424-5p, miR-15b, miR-233, miR-452-5p, miR-629-5p, miR-25, miR-155, miR-23a-3p, miR-519c-3p, miR-374b-5p, miR-374a, miR-31-5p, miR-3163, miR-525-5p, miR-15-5p, miR-374a-5p, miR-374b-5p, miR-218-5p, miR-141-3p and miR-200a-3p to regulate expression of their mRNA targets. The current review summarizes the role of MAGI2-AS3 in different disorders to highlight its importance in their pathophysiology.

Comprehensive analysis of the FOXA1-related ceRNA network and identification of the MAGI2-AS3/DUSP2 axis as a prognostic biomarker in prostate cancer.

Background: Prostate cancer (PCa) is the second most common cause of cancer-related deaths in American men. Even though increasing evidence has disclosed the competitive endogenous RNA (ceRNA) regulatory networks among cancers, the complexity and behavior characteristics of the ceRNA network in PCa remain unclear. Our study aimed to investigate the forkhead box A1 (FOXA1)-related ceRNA regulatory network and ascertain potential prognostic markers associated with PCa. Methods: RNA sequence profiles downloaded from The Cancer Genome Atlas (TCGA) were analyzed to recognize differentially expressed genes (DEGs) derived from tumor and non-tumor adjacent samples as well as FOXA1low and FOXA1high tumor samples. The enrichment analysis was conducted for the dysregulated mRNAs. The network for the differentially expressed long non-coding RNA (lncRNA)-associated ceRNAs was then established. Survival analysis and univariate Cox regression analysis were executed to determine independent prognostic RNAs associated with PCa. The correlation between DUSP2 and immune cell infiltration level was analyzed. Tissue and blood samples were collected to verify our network. Molecular experiments were performed to explore whether DUSP2 is involved in the development of PCa. Results: A ceRNA network related to FOXA1 was constructed and comprised 18 lncRNAs, 5 miRNAs, and 44 mRNAs. The MAGI2-AS3~has-mir-106a/has-mir-204~DUSP2 ceRNA regulatory network relevant to the prognosis of PCa was obtained by analysis. We markedly distinguished the MAGI2-AS3/DUSP2 axis in the ceRNA. It will most likely become a clinical prognostic model and impact the changes in the tumor immune microenvironment of PCa. The abnormal MAGI2-AS3 expression level from the patients' blood manifested that it would be a novel potential diagnostic biomarker for PCa. Moreover, down-expressed DUSP2 suppressed the proliferation and migration of PCa cells. Conclusions: Our findings provide pivotal clues to understanding the role of the FOXA1-concerned ceRNA network in PCa. Simultaneously, this MAGI2-AS3/DUSP2 axis might be a new significant prognostic factor associated with the diagnosis and prognosis of PCa.

MAGI2-AS3 and miR-374b-5p as Putative Regulators of Multiple Sclerosis via Modulating the PTEN/AKT/IRF-3/IFN-ß Axis: New Clinical Insights.

Multiple sclerosis (MS) is a chronic disease and one of the leading causes of disability in young adults. The current study aims to investigate the pathogenesis of MS via studying the regulatory role of novel lncRNA MAGI2-AS3 in miR-374b-5p and their downstream targets PTEN/AKT/IRF-3/IFN-ß and the relationship of this pathway with disease severity. Moreover, it aims to assess the role of MAGI2-AS3/miR-374b-5p as diagnostic and/or prognostic biomarkers for MS. Overall, 150 contributors were recruited: 100 patients with MS and 50 healthy volunteers. Gene expression of MAGI2-AS3, miR-374b-5p, PTEN, AKT, and IRF-3 were assessed using RT-qPCR, and IFN-ß was measured by ELISA. Compared with the healthy control group, serum MAGI2-AS3 and PTEN were downregulated in MS patients, whereas miR-374b-5p, PI3K, AKT, IRF-3, and IFN-ß were upregulated in MS patients. Furthermore, MAGI2-AS3 was downregulated, while miR-374b-5p was upregulated in MS patients with an expanded disability status scale (EDSS) ≥3.5, compared to patients with an EDSS <3.5. Receiver-operating-characteristic curve analysis revealed that MAGI2-AS3 and miR-374b-5p can be used in the diagnosis of MS. Remarkably, multivariate logistic analysis revealed that MAGI2-AS3, miR-374b-5p, PTEN, and AKT act as independent variables in MS. Moreover, MAGI2-AS3 was directly correlated with PTEN and inversely correlated with miR-374b-5p, AKT, and EDSS. Regarding miR-374b-5p, it was positively correlated with AKT and EDSS. In conclusion, the study showed for the first time that the crosstalk between MAGI2-AS3 and miR-374b-5p could affect the AKT/IRF3/IFN-ß axis in MS. Interestingly, MAGI2-AS3 and miR-374b-5p could be genetic noninvasive biomarkers for MS.

lncRNA MAGI2-AS3 suppresses castration-resistant prostate cancer proliferation and migration via the miR-106a-5p/RAB31 axis.

Prostate cancer (PCa) is a common malignant cancer in elderly males in Western countries. Whole-genome sequencing confirmed that long non-coding RNAs (lncRNAs) are frequently altered in castration-resistant prostate cancer (CRPC) and promote drug resistance to cancer therapy. Therefore, elucidating the prospective role of lncRNAs in PCa oncogenesis and progression is of remarkable clinical significance. In this study, gene expression in prostate tissues was determined using RNA-sequencing datasets, and the gene diagnostic and prognostic values of CRPC were analyzed using bioinformatics. Further, the expression levels and clinical significance of MAGI2 Antisense RNA 3 (MAGI2-AS3) in PCa clinical specimens were evaluated. The tumor-suppressive activity of MAGI2-AS3 was functionally explored in PCa cell lines and animal xenograft models. MAGI2-AS3 was found to be aberrantly decreased in CRPC and was negatively correlated with Gleason score and lymph node status. Notably, low MAGI2-AS3 expression positively correlated with poorer survival in patients with PCa. The overexpression of MAGI2-AS3 significantly inhibited the proliferation and migration of PCa in vitro and in vivo. Mechanistically, MAGI2-AS3 could play a tumor suppressor function in CRPC through a novel miR-106a-5p/RAB31 regulatory network and could be a target for future cancer therapy.

Hypermethylation-Mediated lncRNA MAGI2-AS3 Downregulation Facilitates Malignant Progression of Laryngeal Squamous Cell Carcinoma via Interacting With SPT6.

Long noncoding RNAs (lncRNAs) have an effect on the occurrence and progression of a considerable number of diseases, especially cancer. Existing research has suggested that MAGI2 antisense RNA 3 (MAGI2-AS3) takes on a critical significance in the development of hepatocellular carcinoma and lung cancer. However, the functions of MAGI2-AS3 in laryngeal squamous cell carcinoma (LSCC) remain unclear. In this study, MAGI2-AS3 expression level in LSCC tissue and cell lines was detected, and the effect of MAGI2-AS3 overexpressed on LSCC phenotypes and the possible influence mechanisms were examined. MAGI2-AS3 was downregulated in the tissues of LSCC patients versus non-tumor tissues, and it was correlated with advanced TNM (tumor, node, metastasis) stage and lymph node metastases, as indicated by the results of this study. MAGI2-AS3 inhibited the proliferation, migration, and invasion of LSCC cells in vitro and in vivo. Furthermore, the hypermethylation level of the MAGI2-AS3 promoter region was indicated by bisulfite genomic sequencing and methylation-specific polymerase chain reaction, such that MAGI2-AS3 expression was downregulated. Besides, MAGI2-AS3 promoter hypermethylation was regulated by DNA methyltransferase 1 (DNMT1), and MAGI2-AS3 expression was reversed by 5-Aza-2'-deoxycytidine (5-Aza). Moreover, the result of the RNA pull-down experiment suggested that 38 proteins were enriched in the MAGI2-AS3 group versus the control group in TU177 cells. To be specific, SPT6 (ie, a conserved protein) was enriched by fold change >10. SPT6 knockdown reduced the antitumor effect of MAGI2-AS3 in TU177 and AMC-HN-8 cells. Meanwhile, SPT6 overexpression inhibited the proliferation, metastasis, and invasion of TU177 and AMC-HN-8 cells. As revealed by the above findings, DNMT1-regulated MAGI2-AS3 promoter hypermethylation led to downregulated MAGI2-AS3 expression, such that the presence and progression of LSCC were inhibited in an SPT6 binding-dependent manner.

Identification and Verification of a Novel MAGI2-AS3/miRNA-374-5p/FOXO1 Network Associated with HBV-Related HCC.

BACKGROUND: Hepatocellular carcinoma (HCC) is a very common neoplasm worldwide, and competitive endogenous RNA (ceRNA) plays an important role in the development of HCC. The purpose of this study is to investigate the molecular mechanisms of ceRNAs in HCC. METHODS: This study detects potential ceRNAs from HCC through whole genome analysis of lncRNA, miRNA and mRNA expression. We then performed high-throughput sequencing of tissues from five hepatitis B related HCC patients to screen ceRNAs and those screened ceRNAs expressions were verified on tissues from an independent group of six patients. Finally, the function of ceRNAs of interest was illustrated in vitro. RESULT: Functional and pathway analysis of The Cancer Genome Atlas revealed ceRNA networks. The high-throughput sequencing identified 985 upregulated and 1612 downregulated lncRNAs and 887 upregulated and 1116 downregulated mRNAs in HCC patients. Differentially expressed genes were parallel to cancer-associated processes, comprising 18 upregulated and 35 downregulated significantly enriched pathways including alcoholism and viral carcinogenesis. Among them, a potential ceRNA network was detected and verified in six HCC patients. CeRNAs of the lncRNA MAGI2-AS3/miR-374-5p/FOXO1 pathway were significantly dysregulated in HCC, and validation in vitro showed that FOXO1 is positively regulated by MAGI2-AS3 through the induction of miR-374a/b-5p in HCC cells. In addition, the overexpression of FOXO1 is associated with proliferation, migration, and invasion of HCC cells and increases apoptosis of HCC cells. MiR-374a/b-5p caused an opposite effect by directly suppressing FOXO1 in HCC cells. CONCLUSION: CeRNA networks were found in HCC and aberrantly expressed ceRNAs of lncRNA MAGI2-AS3/miR-374-5p/FOXO1 plays a crucial role in HCC, assisting in diagnosis and providing a method for treatment.

Long noncoding RNA MAGI2-AS3 regulates the H2O2 level and cell senescence via HSPA8.

The redox homeostasis system regulates many biological processes, intracellular antioxidant production and redox signaling. However, long noncoding RNAs (lncRNAs) involved in redox regulation have rarely been reported. Herein, we reported that downregulation of MAGI2-AS3 decreased the superoxide level in Human fibroblasts (Fbs), a replicative aging model, as detected by the fluorescent probes dihydroethidium (DHE) and MitoSOX™ Red. RNA pulldown combined with mass spectrometry showed that HSPA8 is a novel interacting protein of MAGI2-AS3, which was further confirmed by photoactivatable ribonucleoside-enhanced crosslinking and immunoprecipitation (PAR-CLIP). Downregulation of MAGI2-AS3 decreased the hydrogen peroxide (H2O2) content by stabilizing the HSPA8 protein level via inhibiting the protesome degradation of HSPA8. Further evidence showed that MAGI2-AS3 interacted with the C-terminal domain (CTD) of HSPA8. Downregulation of MAGI2-AS3 delayed cell senescence, while this antiaging effect was abolished by HSPA8 knockdown. The underlying molecular mechanism by which MAGI2-AS3 knockdown inhibited cell senescence was mediated via suppression of the ROS/MAP2K6/p38 signaling pathway. Taken together, these findings revealed that downregulation of lncRNA MAGI2-AS3 decreased the H2O2 content and delayed cell senescence by stabilizing the HSPA8 protein level, identifying a potential antiaging application.

MAGI2-AS3 restrains proliferation, glycolysis, and triggers apoptosis in acute lymphoblastic leukemia via regulating miR-452-5p/FOXN3 pathway.

Objectives: MAGI2-AS3 is a cancer suppressor gene of multiple malignancies. Acute lymphoblastic leukemia (ALL) is an important type of leukemia that especially occurs in children. Our work evaluated the modulation of MAGI2-AS3 in ALL. Materials and Methods: qPCR and Western blotting were adopted for detection of target molecular expression. Growth and apoptosis were determined by CCK8 assay and Annexin V/PI staining. Glycolysis was detected by commercial kits. The direct binding between miR-452-5p and MAGI2-AS3 or FOXN3 was assessed by luciferase reporter assay. Tumor growth was measured in nude mice in vivo. Results: MAGI2-AS3 was down-regulated in ALL. Enforced expression of MAGI2-AS3 inhibited growth and glycolysis while promoting apoptosis of ALL cells. Moreover, MAGI2-AS3 up-regulated FOXN3 via sponging miR-452-5p. FOXN3 depletion abrogated MAGI2-AS3-mediated anti-cancer action. More importantly, MAGI2-AS3 repressed ALL cell growth in nude mice through regulation of miR-452-5p/FOXN3. Conclusion: MAGI2-AS3 inhibits ALL development via modulating miR-452-5p/FOXN3.

MicroRNA MiR-490-5p suppresses pancreatic cancer through regulating epithelial-mesenchymal transition via targeting MAGI2 antisense RNA 3.

Pancreatic cancer with about 5% five-year overall survival rate remains a challenge. Invasion and migration of pancreatic cancer cells are the main factors leading to poor prognosis. MicroRNA-490-5p (miR-490-5p) has anti-cancer effects in a variety of tumors, but its role in pancreatic cancer has not been reported. The mRNA expressions of miR-490-5p, MAGI2 antisense RNA 3 (MAGI2-AS3), Matrix metalloproteinase (MMP)2, MMP9, N-cadherin, and E-cadherin were detected by quantitative real-time PCR, while the protein expressions of these genes except miR-490-5p were measured by Western blot analysis. The cell viability, apoptosis, migration and invasion were detected by cell counting kit-8 (CCK-8), apoptosis and transwell assays. MiR-490-5p was abnormally low-expressed in pancreatic cancer, whose down-regulation generated enhanced effects on viability, migration and invasion in pancreatic cancer cells, as well as MAGI2-AS3 expression. MiR-490-5p mimic exerted the opposite effect on cells, which also down-regulated MMP2, MMP9, and N-cadherin protein expressions, while up-regulating E-cadherin protein expression. MAGI2-AS3, which was the targeted binding site of miR-490-5p, promoted viability, migration and invasion, and inhibited apoptosis of cancer cells. More importantly, miR-490-5p played an anti-cancer role in pancreatic cancer by targeting MAGI2-AS3 and regulating epithelial-mesenchymal transition (EMT), which was partially offset by MAGI2-AS3.

Long non-coding RNA MAGI2-AS3 inactivates STAT3 pathway to inhibit prostate cancer cell proliferation via acting as a microRNA-424-5p sponge.

Aberrant expression of long non-coding RNAs (lncRNAs) that results in sustained activation of cell growth promoting pathways is an important mechanism in driving prostate cancer progression. In the present study, we explored differentially expressed lncRNAs in two microarray datasets of prostate benign and malignant tissues. We found that MAGI2-AS3 was one of the most downregulated lncRNAs in prostate tumors, which was further confirmed in our collected clinical samples. The function assays showed that MAGI2-AS3 overexpression decreased cell viability and led to obvious cell apoptosis in PC-3 and DU145 prostate cancer cells. Elevation of MAGI2-AS3 decreased the activity of STAT3 in PC-3 and DU145. In addition, microRNA-424-5p (miR-424-5p), a positive regulator of STAT3 pathway, was predicted as a target of MAGI2-AS3, furthermore, the interaction between MAGI2-AS3 and miR-424-5p was confirmed via reverse-transcript polymerase chain reaction (RT-qPCR), dual luciferase reporter assay and RNA immunoprecipitation (RIP). MAGI2-AS3 upregulated miR-424-5p and downregulated COP1 in PC-3 and DU145. More importantly, IL6-induced activation of STAT3 pathway could attenuate the biological effect of MAGI2-AS3 in PC-3 and DU145. In clinical samples, MAGI2-AS3 levels were negatively correlated with miR-424-5p expression, while positively correlated with COP1 mRNA expression. Altogether, the current study revealed MAGI2-AS3 as a novel negative regulator of prostate cancer development.

A New Story of the Three Magi: Scaffolding Proteins and lncRNA Suppressors of Cancer.

Scaffolding molecules exert a critical role in orchestrating cellular response through the spatiotemporal assembly of effector proteins as signalosomes. By increasing the efficiency and selectivity of intracellular signaling, these molecules can exert (anti/pro)oncogenic activities. As an archetype of scaffolding proteins with tumor suppressor property, the present review focuses on MAGI1, 2, and 3 (membrane-associated guanylate kinase inverted), a subgroup of the MAGUK protein family, that mediate networks involving receptors, junctional complexes, signaling molecules, and the cytoskeleton. MAGI1, 2, and 3 are comprised of 6 PDZ domains, 2 WW domains, and 1 GUK domain. These 9 protein binding modules allow selective interactions with a wide range of effectors, including the PTEN tumor suppressor, the ß-catenin and YAP1 proto-oncogenes, and the regulation of the PI3K/AKT, the Wnt, and the Hippo signaling pathways. The frequent downmodulation of MAGIs in various human malignancies makes these scaffolding molecules and their ligands putative therapeutic targets. Interestingly, MAGI1 and MAGI2 genetic loci generate a series of long non-coding RNAs that act as a tumor promoter or suppressor in a tissue-dependent manner, by selectively sponging some miRNAs or by regulating epigenetic processes. Here, we discuss the different paths followed by the three MAGIs to control carcinogenesis.

GLIDR promotes the progression of glioma by regulating the miR-4677-3p/MAGI2 axis.

Gliomas are the most common and fatal primary brain tumors. Growing evidence suggests that long non-coding RNAs (lncRNAs) constitute novel and potential therapeutic targets for glioma. However, the biological role of glioblastoma down-regulated RNA (GLIDR) in glioma remains largely elusive. In the current study, we used quantitative real-time polymerase chain reaction (qRT-PCR) to detect GLIDR expression in glioma cells. Cell counting kit 8 (CCK-8) assay, colony formation assay, JC-1 staining, and flow cytometry were used to evaluate the role of GLIDR in proliferation and apoptosis of glioma cells. Western blotting was performed to assess the effect of GLIDR on the level of apoptosis-related proteins. In addition, bioinformatics prediction, RNA immunoprecipitation (RIP), RNA pull-down, and luciferase reporter gene assays were used to study the regulatory mechanisms of GLIDR in glioma. GLIDR was found to be highly expressed in glioma cells and silencing of GLIDR inhibited cell proliferation and promoted apoptosis. Functionally, GLIDR bound to miR-4677-3p that directly targeted membrane-associated guanylate kinase, WW, and PDZ domain-containing protein 2 (MAGI2). Our data showed that GLIDR affects the proliferation and apoptosis of glioma cells by targeting miR-4677-3p to regulate the expression of MAGI2. In conclusion, our study determined the oncogenic role of GLIDR in glioma, which may provide a new perspective for the treatment of glioma.

Phase Separation of MAGI2-Mediated Complex Underlies Formation of Slit Diaphragm Complex in Glomerular Filtration Barrier.

BACKGROUND: Slit diaphragm is a specialized adhesion junction between the opposing podocytes, establishing the final filtration barrier to urinary protein loss. At the cytoplasmic insertion site of each slit diaphragm there is an electron-dense and protein-rich cellular compartment that is essential for slit diaphragm integrity and signal transduction. Mutations in genes that encode components of this membrane-less compartment have been associated with glomerular diseases. However, the molecular mechanism governing formation of compartmentalized slit diaphragm assembly remains elusive. METHODS: We systematically investigated the interactions between key components at slit diaphragm, such as MAGI2, Dendrin, and CD2AP, through a combination of biochemical, biophysical, and cell biologic approaches. RESULTS: We demonstrated that MAGI2, a unique MAGUK family scaffold protein at slit diaphragm, can autonomously undergo liquid-liquid phase separation. Multivalent interactions among the MAGI2-Dendrin-CD2AP complex drive the formation of the highly dense slit diaphragm condensates at physiologic conditions. The reconstituted slit diaphragm condensates can effectively recruit Nephrin. A nephrotic syndrome-associated mutation of MAGI2 interfered with formation of the slit diaphragm condensates, thus leading to impaired enrichment of Nephrin. CONCLUSIONS: Key components at slit diaphragm (e.g., MAGI2 and its complex) can spontaneously undergo phase separation. The reconstituted slit diaphragm condensates can be enriched in adhesion molecules and cytoskeletal adaptor proteins. Therefore, the electron-dense slit diaphragm assembly might form via phase separation of core components of the slit diaphragm in podocytes.

Roles of lncRNA MAGI2-AS3 in human cancers.

Long noncoding RNAs (lncRNAs) are noncoding RNAs more than 200 nucleotides in length. A growing number of reports indicate that lncRNAs play a key role in multiple cancers by serving as oncogenes or tumor suppressor genes. MAGI2 antisense RNA 3 (MAGI2-AS3) is ubiquitously expressed in human cancers, and the level of MAGI2-AS3 expression is associated with the progression and prognosis of cancers. Moreover, dysregulation of MAGI2-AS3 has been found to regulate cancer cell proliferation, cell death, invasion and metastasis and treatment resistance by serving as a competing endogenous RNA (ceRNA), epigenomic regulator, and transcriptional regulator. Moreover, increasing evidence shows that MAGI2-AS3 may be a potential biomarker for cancer prognosis and a potential target for cancer therapy. In this review, we summarize current research on the functions, mechanisms and clinical significance of the lncRNA MAGI2-AS3 in cancer development.