MicroRNA-361-5p inhibits epithelial-to-mesenchymal transition of glioma cells through targeting Twist1

An overview of Twist1 in glioma progression and recurrence

Glioma cells are characterized by high migration ability, resulting in the aggressive growth of the tumors and poor prognosis of patients. Epithelial-to-mesenchymal transition (EMT) is one of the most important steps for tumor migration and metastasis and be elevated during glioma progression and recurrence. Twist1 is a basic helix-loop-helix transcription factor and a key transcription factor involved in the process of EMT. Twist1 is related to glioma mesenchymal change, invasion, heterogeneity, self-renewal of tumor stem cells, angiogenesis, etc., and may be used as a prognostic indicator and therapeutic target for glioma patients. This paper mainly reviews the structural characteristics, regulatory mechanisms, and apparent regulation of Twist1, as well as the roles of Twist1 during glioma progression and recurrence, providing new revelations for its use as a potential drug target and glioma treatment research.

Zinc Finger E-Box Binding Homeobox Family: Non-Coding RNA and Epigenetic Regulation in Gliomas

Gliomas are the most common malignant brain tumours. Among them, glioblastoma (GBM) is a grade four tumour with a median survival of approximately 15 months and still limited treatment options. Although a classical epithelial to mesenchymal transition (EMT) is not the case in glioma due to its non-epithelial origin, the EMT-like processes may contribute largely to the aggressive and highly infiltrative nature of these tumours, thus promoting invasive phenotype and intracranial metastasis. To date, many well-known EMT transcription factors (EMT-TFs) have been described with clear, biological functions in glioma progression. Among them, EMT-related families of molecules such as SNAI, TWIST and ZEB are widely cited, well-established oncogenes considering both epithelial and non-epithelial tumours. In this review, we aimed to summarise the current knowledge with a regard to functional experiments considering the impact of miRNA and lncRNA as well as other epigenetic modifications, with a main focus on ZEB1 and ZEB2 in gliomas. Although we explored various molecular interactions and pathophysiological processes, such as cancer stem cell phenotype, hypoxia-induced EMT, tumour microenvironment and TMZ-resistant tumour cells, there is still a pressing need to elucidate the molecular mechanisms by which EMT-TFs are regulated in gliomas, which will enable researchers to uncover novel therapeutic targets as well as improve patients' diagnosis and prognostication.

An evaluation of the role of miR-361-5p in senescence and systemic ageing

Senescent cells are key regulators of ageing and age-associated disease. MicroRNAs (miRs) are a key component of the molecular machinery governing cellular senescence, with several known to regulate important genes associated with this process. We sought to identify miRs associated with both senescence and reversal by pinpointing those showing opposing directionality of effect in senescence and in response to senotherapy. Cellular senescence phenotypes were assessed in primary human endothelial cells following targeted manipulation of emergent miRNAs. Finally, the effect of conserved target gene knockdown on lifespan and healthspan was assessed in a C. elegans system in vivo. Three miRNAs (miR-5787, miR-3665 and miR-361-5p) demonstrated associations with both senescence and rejuvenation, but miR-361-5p alone demonstrated opposing effects in senescence and rescue. Treatment of late passage human endothelial cells with a miR-361-5p mimic caused a 14 % decrease in the senescent load of the culture. RNAi gene knockdown of conserved miR-361-5p target genes in a C. elegans model however resulted in adverse effects on healthspan and/or lifespan. Although miR-361-5p may attenuate aspects of the senescence phenotype in human primary endothelial cells, many of its validated target genes also play essential roles in the regulation or formation of the cytoskeletal network, or its interaction with the extracellular matrix. These processes are essential for cell survival and cell function. Targeting miR-361-5p alone may not represent a promising target for future senotherapy; more sophisticated approaches to attenuate its interaction with specific targets without roles in essential cell processes would be required.

B-cell Lymphoma 6 (BCL6): From Master Regulator of Humoral Immunity to Oncogenic Driver in Pediatric Cancers

B-cell lymphoma 6 (BCL6) is a protooncogene in adult and pediatric cancers, first identified in diffuse large B-cell lymphoma (DLBCL) where it acts as a repressor of the tumor suppressor TP53, conferring survival, protection, and maintenance of lymphoma cells. BCL6 expression in normal B cells is fundamental in the regulation of humoral immunity, via initiation and maintenance of the germinal centers (GC). Its role in B cells during the production of high affinity immunoglobins (that recognize and bind specific antigens) is believed to underpin its function as an oncogene. BCL6 is known to drive the self-renewal capacity of leukemia-initiating cells (LIC), with high BCL6 expression in acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), and glioblastoma (GBM) associated with disease progression and treatment resistance. The mechanisms underpinning BCL6-driven therapy resistance are yet to be uncovered; however, high activity is considered to confer poor prognosis in the clinical setting. BCL6's key binding partner, BCL6 corepressor (BCOR), is frequently mutated in pediatric cancers and appears to act in concert with BCL6. Using publicly available data, here we show that BCL6 is ubiquitously overexpressed in pediatric brain tumors, inversely to BCOR, highlighting the potential for targeting BCL6 in these often lethal and untreatable cancers. In this review, we summarize what is known of BCL6 (role, effect, mechanisms) in pediatric cancers, highlighting the two sides of BCL6 function, humoral immunity, and tumorigenesis, as well as to review BCL6 inhibitors and highlight areas of opportunity to improve the outcomes of patients with pediatric cancer.

PTBP3 promotes tumorigenesis of glioblastoma by stabilizing Twist1

•

PTBP3 is upregulated in GBM and predicts poor prognosis.

•

PTBP3 promotes proliferation, EMT, migration, and invasion of GBM.

•

PTBP3 stabilizes Twist1 by decreasing its ubiquitination and degradation.

Objective

Glioblastoma (GBM) is the most common malignancy tumor of central nervous system. PTBP3 was closely associated with the development of tumor. However, the function and molecular mechanism of PTBP3 in GBM is little known.

Methods

qPCR and immunoblotting were used to detect PTBP3 expression levels in glioma tissues and cells. CCK8, Edu, flow cytometry, wound healing, and transwell assays were used to examined the function of PTBP3 in GBM. qPCR, Immunoblotting, and ubiquitination assays were performed to identify the mechanism of PTBP3.

Results

We found that PTBP3 was upregulated in GBM, and high expression of PTBP3 correlated with the poor survival of GBM patients. PTBP3 knockdown reduced proliferation, invasion, and migration of GBM. Conversely, overexpressing PTBP3 has an opposite effect. Moreover, PTBP3 had an effect on the EMT of GBM. More importantly, we found that PTBP3 stabilized Twist1 by decreasing its ubiquitination and degradation. Furthermore, orthotopic xenograft models were used to demonstrate the PTBP3 on the development of GBM in vivo.

Conclusion

This study proved that PTBP3 promoted tumorigenesis of GBM by stabilizing Twist1, which provided a new therapeutic target for GBM.

The Crucial Roles of Bmi-1 in Cancer: Implications in Pathogenesis, Metastasis, Drug Resistance, and Targeted Therapies

B-cell-specific Moloney murine leukemia virus integration region 1 (Bmi-1, also known as RNF51 or PCGF4) is one of the important members of the PcG gene family, and is involved in regulating cell proliferation, differentiation and senescence, and maintaining the self-renewal of stem cells. Many studies in recent years have emphasized the role of Bmi-1 in the occurrence and development of tumors. In fact, Bmi-1 has multiple functions in cancer biology and is closely related to many classical molecules, including Akt, c-MYC, Pten, etc. This review summarizes the regulatory mechanisms of Bmi-1 in multiple pathways, and the interaction of Bmi-1 with noncoding RNAs. In particular, we focus on the pathological processes of Bmi-1 in cancer, and explore the clinical relevance of Bmi-1 in cancer biomarkers and prognosis, as well as its implications for chemoresistance and radioresistance. In conclusion, we summarize the role of Bmi-1 in tumor progression, reveal the pathophysiological process and molecular mechanism of Bmi-1 in tumors, and provide useful information for tumor diagnosis, treatment, and prognosis.

LncRNA GATA3-AS1 promoted invasion and migration in human endometrial carcinoma by regulating the miR-361/ARRB2 axis

Endometrial carcinoma (EC) is a kind of fatal female malignancy. lncRNA GATA3-AS1 has been identified as an oncogene in various cancers. However, the functions and mechanisms of GATA3-AS1 in EC remain to be explored. Human EC tissues and four EC cell lines were used. Western blotting and quantitative real-time PCR (qRT-PCR) were used to evaluate the expression of GATA3-AS1, miR-361, and ARRB2. Dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were used to validate the interaction among GATA3-AS1, miR-361, and ARRB2. Flow cytometry, colony formation assay, scratch assay, and transwell assay were used to examine the cell apoptosis, proliferation, migration, and invasion of EC cells, respectively. In vivo tumor growth was monitored in nude mice. GATA3-AS1 and ARRB2 were upregulated while miR-361 was downregulated in human EC tissues and EC cells. GATA3-AS1 knockdown constrained cell proliferation, invasion, migration, and EMT while promoting the apoptosis of EC cells by upregulating miR-361. GATA3-AS1 negatively regulated miR-361 expression. ARRB2 was the direct target of miR-361 and could activate the Src/Akt pathway. In vivo, GATA3-AS1 knockdown suppressed tumor progression by upregulating the miR-361 expression. lncRNA GATA3-AS1 promoted EC invasion and migration by the miR-361/ARRB2 axis, which indicated that GATA3-AS1 might be a promising therapeutic option for advanced EC progression. KEY MESSAGES: GATA3-AS1 knockdown suppressed EC proliferation, invasion, and migration. GATA3-AS1 directly inhibited miR-361 as a ceRNA. MiR-361 knockdown reversed the tumor suppressive effect caused by GATA3-AS1 knockdown. MiR-361 bound to ARRB2 directly and suppressed its expression. The GATA3-AS1/miR-361/ARRB2 axis regulated EC cell proliferation, invasion, and migration.

Comprehensive analysis of negatively correlated miRNA-mRNA regulatory pairs associated with microsatellite instability in colorectal cancer

BACKGROUND: Several studies have demonstrated that microRNAs (miRNAs) and target mRNAs are associated with different frequencies of microsatellite instability. OBJECTIVE: The study aimed to elucidate the profiles of miRNAs and target mRNAs expression and their associations with the phenotypic hallmarks of microsatellite instability in colorectal cancers (CRC) by integrating transcriptomic, immunophenotype, methylation, mutation, and survival data. METHODS: Differentially expressed miRNAs (DEmiRNAs) and mRNAs (DEmRNAs) were screened out and then the miRNA-mRNA regulatory pairs were identified through two databases. We verified that the expression levels were detected in 40 microsatellite instable (MSI) and 40 microsatellite stable (MSS) CRC samples and used the logistic regression and the Cox regression method to evaluate the diagnostic and prognostic value of negative regulatory pairs respectively. RESULTS: The best diagnostic model that combines miR-31-5p, PLAGL2, miR-361-5p, and RAB27B, which were associated with immune microenvironment, tumor mutation burden (TMB), and overall DNA methylation, could significantly predict microsatellite instability in colon tissues. MiR-31-5p and RAB27B could also predict the overall survival of MSS CRCs. CONCLUSION: This study generated a predictive model of the combination of miRNAs and mRNAs to distinguish MSI versus MSS CRCs and elaborated their potential molecular mechanisms and biological functions.

G-protein Coupled Receptor 34 Promotes Gliomagenesis by Inducing Proliferation and Malignant Phenotype via TGF-Beta/Smad Signaling Pathway

Background: G-protein coupled receptor 34 (GPR34) is involved in cell motility, differentiation, and mitosis. GPR34 was reported to be highly expressed and play an oncogenic role in several solid tumors. Here, we investigated the mechanisms underlying how GPR34 promotes glioma progression. Methods: Bioinformatic analysis was performed on RNA-seq and clinical data from the gene expression omnibus (GEO), cancer genome atlas (TCGA), and Genotype-Tissue Expression (GTEx) databases. TIMER database and single-sample GSEA (ssGAEA) method were used to investigate the association between the GPR34 expression and immune infiltration level in glioma. Cox regression analysis was employed to ascertain whether the risk signature was an independent prognostic indicator for glioma. The viability and migratory/invasive potential of glioma cells were assessed using Cell Counting Kit-8, colony formation, wound healing, and Transwell assays. Results: We found that GPR34 expression was positively correlated with immune infiltration level and that high GPR34 level may be associated with poor prognosis in glioma. We further found that GPR34 may serve as an independent prognostic marker and prediction factor for the clinicopathological features of glioma. We showed that knocking down GPR34 attenuated the viability and migratory/invasive capacity of glioma cells (U251 and LN229), while GPR34 overexpression exerted the opposite effects. Additionally, core enrichment in the GSEA analysis indicated that GPR34-mediated gliomagenesis was associated with the cell cycle arrest, epithelial–mesenchymal transition (EMT), and activation of the TGF-β/Smad pathway; furthermore, inhibiting TGF-β/Smad signaling using LY2157299, a TGF-β inhibitor, reversed the oncogenic effects and malignant phenotype associated with GPR34 overexpression. Conclusion: GPR34 enhances the malignancy and carcinogenesis of glioma by promoting an EMT-like process, G1/S phase cell cycle transition, and TGF-β/Smad signaling. Accordingly, GPR34 likely functions as an oncogene in glioma and may represent a potential therapeutic target for this cancer.

MicroRNA-361-5p slows down gliomas development through regulating UBR5 to elevate ATMIN protein expression

MicroRNA (miR)-361-5p has been studied to suppress gliomas development. Based on that, an insight into the regulatory mechanism of miR-361-5p in gliomas was supplemented from ubiquitin protein ligase E3 component N-recognin 5 (UBR5)-mediated ubiquitination of ataxia-telangiectasia mutated interactor (ATMIN). miR-361-5p, ATMIN, and UBR5 levels were clinically analyzed in gliomas tissues, which were further validated in gliomas cell lines. Loss/gain-of-function method was applied to determine the roles of miR-361-5p and UBR5 in gliomas, as to cell viability, migration, invasion, colony formation ability, and apoptosis in vitro and tumorigenesis in vivo. The relationship between miR-361-5p and UBR5 was verified and the interaction between UBR5 and ATMIN was explored. It was detected that reduced miR-361-5p and ATMIN and enhanced UBR5 levels showed in gliomas. Elevating miR-361-5p was repressive in gliomas progression. UBR5 was directly targeted by miR-361-5p. UBR5 can ubiquitinate ATMIN. miR-361-5p suppressed gliomas by regulating UBR5-mediated ubiquitination of ATMIN. Downregulating UBR5 impeded gliomas tumor growth in vivo. Upregulating miR-361-5p targets UBR5 to promote ATMIN protein expression, thus to recline the malignant phenotype of gliomas cells.

Competing Endogenous RNA Networks in Glioma

Gliomas are the most common and malignant primary brain tumors. Various hallmarks of glioma, including sustained proliferation, migration, invasion, heterogeneity, radio- and chemo-resistance, contribute to the dismal prognosis of patients with high-grade glioma. Dysregulation of cancer driver genes is a leading cause for these glioma hallmarks. In recent years, a new mechanism of post-transcriptional gene regulation was proposed, i.e., "competing endogenous RNA (ceRNA)." Long non-coding RNAs, circular RNAs, and transcribed pseudogenes act as ceRNAs to regulate the expression of related genes by sponging the shared microRNAs. Moreover, coding RNA can also exert a regulatory role, independent of its protein coding function, through the ceRNA mechanism. In the latest glioma research, various studies have reported that dysregulation of certain ceRNA regulatory networks (ceRNETs) accounts for the abnormal expression of cancer driver genes and the establishment of glioma hallmarks. These achievements open up new avenues to better understand the hidden aspects of gliomas and provide new biomarkers and potential efficient targets for glioma treatment. In this review, we summarize the existing knowledge about the concept and logic of ceRNET and highlight the emerging roles of some recently found ceRNETs in glioma progression.

The interplay between non-coding RNAs and Twist1 signaling contribute to human disorders

Twist-related protein 1 (Twist1) is a basic helix-loop-helix (bHLH) transcription factor (TF) being coded by the TWIST1 gene. This TF has a fundamental effect on the normal development and in the pathogenesis of various diseases especially cancer. Twist1 has interactions with some long non-coding RNAs and miRNAs. The interactions between this TF and various miRNAs such as miR-16, miR-26b-5p, miR-1271, miR-539, miR-214, miR-200b/c, miR-335, miR-10b, and miR-381 are implicated in the carcinogenic processes. TP73-AS1, LINC01638, ATB, NONHSAT101069, CASC15, H19, PVT1, LINC00339, LINC01385, TANAR, SNHG5, DANCR, CHRF, and TUG1 are among long non-coding RNAs which interact with Twist1 and participate in the carcinogenesis. This review aims at depicting the interaction between these non-coding transcripts and Twist1 and the consequence of these interactions in human neoplasms.

MicroRNA-361-5p Inhibits Tumorigenesis and the EMT of HCC by Targeting Twist1

MicroRNA-361-5p (miR-361-5p) is a tumor suppressor miRNA that is dysregulated in several types of human cancer. However, the functional significance of miR-361-5p in hepatocellular carcinoma (HCC) is unclear. This study explored the biological function of miR-361-5p in regulating the progression of HCC and the underlying molecular mechanism. RT-qPCR analysis showed that miR-361-5p was downregulated in HCC tissues and cell lines. Functional analysis revealed that miR-361-5p acted as a tumor suppressor, inhibiting cell proliferation, migration, and invasion in HCC cell lines. Bioinformatics analyses identified Twist1 as a direct target of miR-361-5p, which was validated by dual-luciferase reporter assays, RT-qPCR, and western blotting. Rescue experiments indicated that Twist1 may mediate the tumor-suppressive effect of miR-361-5p in HCC cells, and this was supported by the effect of miR-361-5p on inhibiting the epithelial-mesenchymal transition (EMT) by targeting Twist1. This study is the first to suggest that miR-361-5p inhibits tumorigenesis and EMT in HCC by targeting Twist1. These findings are valuable for the diagnosis and clinical management of HCC.

CircPOSTN/miR-361-5p/TPX2 axis regulates cell growth, apoptosis and aerobic glycolysis in glioma cells

Background

Glioma is the most primary central nervous system tumor in adults. The 5 year survival rate for glioma patients remains poor, although treatment strategies had improved in the past few decades. The cumulative studies have shown that circular RNA (circRNA) is associated with glioma process, so the purpose of this study is to clarify the function of circPOSTN in glioma.

Methods

The expression levels of circPOSTN, miR-361-5p, and targeting protein for Xenopus kinesin-like protein 2 (TPX2) were assessed with real-time quantitative polymerase chain reaction (RT-qPCR). The 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazol-3-ium bromide (MTT) and flow cytometry assays were executed to examine proliferation and apoptosis of glioma cells, respectively. Western blot was applied to assess protein expression. The glucose metabolism of glioma cells was analyzed by testing the glucose consumption, lactate production, ATP level, reactive oxygen species (ROS) accumulation and performing Seahorse XF assay. The interaction relationship between miR-361-5p and circPOSTN or TPX2 was analyzed by bioinformatics database and dual-luciferase reporter assay. The influences of circPOSTN silencing in vivo were observed by a xenograft experiment.

Results

CircPOSTN was overexpressed in glioma tissues and cells. Absence of circPOSTN in glioma cells promoted apoptosis while impeded proliferation and aerobic glycolysis, which were mitigated by silencing miR-361-5p. What’s more, loss-of-functional experiment suggested that knockdown of TPX2 repressed proliferation and aerobic glycolysis, while induced apoptosis in glioma cells. In addition, circPOSTN targetedly regulated TPX2 expression in glioma cells via sponging miR-361-5p. In vivo study revealed that deficiency of circPOSTN restrained tumor growth.

Conclusion

Mechanistically, circPOSTN regulated cell growth, apoptosis, and aerobic glycolysis in glioma through miR-361-5p/TPX2 axis.

Chemotherapeutic Stress Influences Epithelial-Mesenchymal Transition and Stemness in Cancer Stem Cells of Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is a subtype of breast cancer characterized by the absence of estrogen and progesterone receptors (ER, PR) and lacking an overexpression of human epidermal growth factor receptor 2 (HER2). Apart from this lack of therapeutic targets, TNBC also shows an increased capacity for early metastasis and therapy resistance. Currently, many TNBC patients receive neoadjuvant chemotherapy (NACT) upon detection of the disease. With TNBC likely being driven at least in part by a cancer stem-like cell type, we wanted to evaluate the response of primary cancer stem cells (CSCs) to standard chemotherapeutics. Therefore, we set up a survival model using primary CSCs to mimic tumor cells in patients under chemotherapy. Breast cancer stem cells (BCSCs) were exposed to chemotherapeutics with a sublethal dose for six days. Surviving cells were allowed to recover in culture medium without chemotherapeutics. Surviving and recovered cells were examined in regard to proliferation, migratory capacity, sphere forming capacity, epithelial–mesenchymal transition (EMT) factor expression at the mRNA level, and cancer-related microRNA (miRNA) profile. Our results indicate that chemotherapeutic stress enhanced sphere forming capacity of BCSCs, and changed cell morphology and EMT-related gene expression at the mRNA level, whereas the migratory capacity was unaffected. Six miRNAs were identified as potential regulators in this process.

Protective Role of Astrocyte-Derived Exosomal microRNA-361 in Cerebral Ischemic-Reperfusion Injury by Regulating the AMPK/mTOR Signaling Pathway and Targeting CTSB

BACKGROUND

Evidence has shown that microRNAs (miRNAs) are implicated in ischemic diseases. Therefore, the aim of the present study was to identify the functions of astrocyte (ATC)-derived exosomal miR-361 on cerebral ischemic-reperfusion (I/R) injury.

METHODS

A rat model of cerebral I/R injury was initially established, followed by injection of ATC-derived exosomes. Next, the protective function of ATC-derived exosomes in rats with cerebral I/R injury was evaluated, and then the effect of miR-361 on rats with cerebral I/R injury was evaluated by changing miR-361 expression in exosomes. PC12 cells that underwent oxygen-glucose deprivation/reoxygenation were used to simulate I/R in vitro. The effect of ATC-derived exosomal miR-361 on the viability and apoptosis of OGD/R-treated PC12 cells was also assessed. The bioinformatic analysis predicted the targeted gene of miR-361.

RESULTS

It was found that I/R was damaging to the brain nerves of rats, while ATC-derived exosomal miR-361 relieved nerve damage caused by I/R. Furthermore, the in vitro experiments demonstrated that ATC-derived exosomal miR-361 increased OGD/R-inhibited PC12 cell activity and suppressed cell apoptosis. Bioinformatics predicted that miR-361 targeted cathepsin B (CTSB). CTSB upregulation blocked the protective roles of miR-361. In addition, miR-361 was found to downregulate the AMPK / mTOR signaling pathway by targeting CTSB.

CONCLUSION

The present study demonstrated that ATC-derived exosomal miR-361 alleviates nerve damage in rats with cerebral I/R injury by targeting CTSB and downregulating the AMPK/mTOR pathway. This may offer novel insights into treatment for I/R injury.

MicroRNA-361: A Multifaceted Player Regulating Tumor Aggressiveness and Tumor Microenvironment Formation

MicroRNA-361-5p (miR-361) expression frequently decreases or is lost in different types of cancers, and contributes to tumor suppression by repressing the expression of its target genes implicated in tumor growth, epithelial-to-mesenchymal transition (EMT), metastasis, drug resistance, glycolysis, angiogenesis, and inflammation. Here, we review the expression pattern of miR-361 in human tumors, describe the mechanisms responsible for its dysregulation, and discuss how miR-361 modulates the aggressive properties of tumor cells and alter the tumor microenvironment by acting as a novel tumor suppressor. Furthermore, we describe its potentials as a promising diagnostic or prognostic biomarker for cancers and a promising target for therapeutic development.

STAT3-induced upregulation of lncRNA MEG3 regulates the growth of cardiac hypertrophy through miR-361-5p/HDAC9 axis

Cardiac hypertrophy is closely correlated with diverse cardiovascular diseases, augmenting the risk of heart failure and sudden death. Long non-coding RNAs (lncRNAs) have been studied in cardiac hypertrophy for their regulatory function. LncRNA MEG3 has been reported in human cancers. Whereas, it is unknown whether MEG3 regulates the growth of cardiac hypertrophy. Therefore, this study aims to investigate the specific role of MEG3 in the progression of cardiac hypertrophy. Here, we found that MEG3 contributed to the pathogenesis of cardiac hypertrophy. MEG3 expression was remarkably strengthened in the mice heart which undergone the transverse aortic constriction (TAC). Moreover, qRT-PCR analysis revealed that MEG3 was upregulated in the cardiomyocytes which were treated with Ang-II. Silenced MEG3 inhibited the increasing size of hypertrophic cardiomyocytes and reversed other hypertrophic responses. Mechanically, MEG3 could affect cardiac hypertrophy by regulating gene expression. Mechanically, we found that MEG3 could be upregulated by the transcription factor STAT3 and could regulate miR-361-5p and HDAC9 by acting as a ceRNA. Finally, rescue assays were made to do further confirmation. All our findings revealed that STAT3-inducetd upregulation of lncRNA MEG3 controls cardiac hypertrophy by regulating miR-362-5p/HDAC9 axis.

miR-186 inhibits proliferation, migration, and epithelial-mesenchymal transition in breast cancer cells by targeting Twist1

OBJECTIVE

Breast cancer (BC) is the most prevalent malignancy in women worldwide. Our study aimed to investigate the expression and biological effect of miR-186 in BC.

METHODS

Expression of miR-186 was determined by quantitative reverse transcription PCR. Kaplan-Meier curves were calculated for the survival data analysis. Functional assays were performed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and wound healing assay. Protein expression was analyzed by Western blot.

RESULTS

miR-186 was downregulated in BC tissues and cells. Downregulation of miR-186 was associated with tumor metastasis and a poor overall survival in patients with BC. Overexpression of miR-186 inhibited BC cells proliferation, migration, and epithelial-mesenchymal transition process; while suppression of miR-186 exhibited an opposite effects on BC cells. In addition, Twist1 was identified as a direct target of miR-186 in BC and restoration of Twist1 attenuated the biological effect of miR-186 on BC cells.

CONCLUSION

Our findings suggest that miR-186 functions as a tumor suppressor by targeting Twist1 in BC. miR-186 may serve as a novel biomarker in BC diagnosis or a new therapeutic target in BC treatment.

miR-361-5p inhibits glioma migration and invasion by targeting SND1

Background

Downregulation of miR-361-5p contributes to epithelial–mesenchymal transition of glioma cells. However, the relevance of miR-361-5p to migration and invasion of gliomas remains unknown.

Materials and methods

The relationship between miR-361-5p and SND1 expression was analyzed in 120 human gliomas and 8 glioma cell lines by in situ hybridization, immunohistochemistry, and Western blot. Dual-luciferase reporter assay was used to identify SND1 as a target of miR-361-5p. The mechanisms through which miR-361-5p inhibits glioma cell migration and invasion were studied by in vitro assays.

Results

miR-361-5p expression was significantly downregulated in glioma tissues and glioma cell lines, and was inversely correlated with glioma grades. However, SND1 expression was positively correlated with glioma grades and inversely correlated with miR-361-5p expression. miR-361-5p overexpression suppressed glioma cell migration and invasion through targeting SND1 and subsequently decreasing MMP-2 expression. In glioma cell lines, SND1 overexpression could partly reverse the antitumor effects of miR-361-5p.

Conclusion

The findings provide evidence that miR-361-5p directly targets SND1 to degradation and then reduces MMP-2 gene transcription, thus inhibiting glioma migration and invasion. miR-361-5p is an important tumor suppressor and a novel diagnostic biomarker of glioma, and miR-361-5p and SND1 are potential therapeutic candidates for malignant gliomas.

MiR-361-5p inhibits the mobility of gastric cancer cells through suppressing epithelial-mesenchymal transition via the Wnt/β-catenin pathway

MiR-361-5p has been reported to be dysregulated in several types of cancers. However, the function of miR-361-5p in gastric cancer (GC) is still not clear. In our present study, we aimed to investigate the effects of miR-361-5p in the mobility of GC and its potential mechanism. We found that miR-361-5p was significantly decreased in GC cell lines and tumor tissues. Decreased miR-361-5p expression was correlated with larger tumor size and advanced TNM stage. Functional analysis revealed that overexpression of miR-361-5p inhibited cell proliferation and mobility through suppressing the expression of MMP-3, MMP-9 and VEGF. Moreover, the expression of epithelial marker E-cadherin was increased while the expression of mesenchymal marker (Snail, N-cadherin, b-catenin) and Wnt/β-catenin pathway related proteins (TCF4, Cyclin-D1, c-Myc) was increased by overexpression of miR-361-5p, indicating that overexpression of miR-361-5p suppressed epithelial-mesenchymal transition (EMT) via inhibiting Wnt/β-catenin pathway in GC cells. In order to further verify our conjecture that miR-361-5p mimic inhibited cell mobility through suppressing EMT via Wnt/β-catenin pathway in GC, the Wnt/β-catenin pathway activator LiCl was used in this study. Our data showed that activation of Wnt/β-catenin pathway by LiCl counteracted the regulating roles of miR-361-5p mimic through promoting EMT and cell mobility. In addition, TCF4 was knockdown and overexpressed in GC cells, and the results convinced the involvement of Wnt pathway in the regulation of EMT. Finally, results from in vivo experiments suggested that overexpression of miR-361-5p suppressed tumor growth and the expression of VEGF markedly through inhibiting EMT via the Wnt/β-catenin pathway in GC nude mice. Taken together, our in vitro and in vivo experiments indicated that miR-361-5p suppressed cell mobility in GC through the inhibition of EMT via Wnt/β-catenin pathway. Our findings indicated that miR-361-5p could be a promising therapeutic target for GC treatment.

RETRACTED: MicroRNA-361-5p inhibits papillary thyroid carcinoma progression by targeting ROCK1

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Authors and Editor-in-Chief. The authors notified the journal and requested retraction of the article, stating: “We recently found that miR-361 did not affect the tumor growth in vivo. All the authors want to retract this paper. Furthermore, we apologize to the readership of the Journal for any inconvenience caused”. The journal was also alerted to an associated PubPeer post, in which images of xenograft tumors within Figure 6B, and images of colony formation assays within Figure 2C, appear to have been published in other articles, as detailed here: https://pubpeer.com/publications/0DA940799BE0D567BAC4659CDAB13F#. The journal requested the corresponding author provide a more detailed explanation to these concerns and associated raw data, but this request was not satisfactorily fulfilled. The Editor-in-Chief assessed the case and decided to retract the article.

MicroRNA-485-5p reduces O-GlcNAcylation of Bmi-1 and inhibits colorectal cancer proliferation

Emerging evidences showed that miRNAs are involved in the oncogenesis of many cancers. Here, miRNA microarray analysis was performed to screen the significant miRNAs involved in the progression of colorectal cancer (CRC), miR-485-5p was chosen for further study. We found that the expression of miR-485-5p was significantly lower in CRC specimens and cell lines. In addition, low expression level of miR-485-5p is correlated with tumor progression and poor survival in CRC patients. Based on in vitro and in vivo assays, we found that miR-485-5p significantly inhibits CRC proliferation. Moreover, our results showed that miR-485-5p inhibits cell proliferation by reducing Bmi-1 protein expression, which has been reported to control the proliferation of many cancers. Mechanistically, OGT is a direct target of miR-485-5p, and miR-485-5p could inhibit the O-GlcNAcylation level of Bmi-1 by OGT. Overall, these results suggested that as a tumor suppressor, miR-485-5p may regulate CRC cells proliferation, which could regulate the O-GlcNAcylation and the stability of Bmi-1 through targeting OGT. This may give insight into a novel mechanism and therapy of CRC growth.

MiR-361-5p suppresses chemoresistance of gastric cancer cells by targeting FOXM1 via the PI3K/Akt/mTOR pathway

Gastric cancer is a prevalent cancer and chemotherapy is a main treatment for patients. Docetaxel is commonly used as a chemotherapeutic drug for gastric cancer patients. With the increasing emergence of docetaxel resistance, exploring the mechanism of chemoresistance may improve prognosis of patients. In this study, we found that overexpressed miR-361-5p suppressed chemoresistance to docetaxel of gastric cancer cells (SGC-7901, MKN-28) by decreasing IC₅₀ values of docetaxel while increasing cell apoptosis rate, especially in docetaxel resistant SGC-7901 cells. Further researches revealed that overexpressed miR-361-5p inhibited chemoresistance through inhibiting autophagy with a characteristic of declined number of LC3⁺ puncta, decreased expression of Beclin-1 and the ratio of LC3 II/I and increased expression of p62. Bioinformatics study and Luciferase reporter assay indicated that FOXM1 was a target of miR-361-5p and FOXM1 was negatively regulated by miR-361-5p in gastric cancer. Simultaneously, overexpression of FOXM1 counteracted the inhibitory effects of miR-361-5p on chemoresistance of gastric cancer cells through activating autophagy, further certifying the targeting relationship between the two. Moreover, overexpressed miR-361-5p activated the PI3K/Akt/mTOR pathway. The adding of PI3K inhibitor LY294002 played an opposite role to miR-361-5p mimic by inducing autophagy and chemoresistance to docetaxel of gastric cancer cells compared with docetaxel + miR-361-5p mimic group, indicating that miR-361-5p suppressed autophagy-induced chemoresistance via the PI3K/Akt/mTOR pathway in gastric cancer cells. In conclusion, we found that miR-361-5p suppressed autophagy-induced chemoresistance of gastric cancer cells through targeting FOXM1 via the PI3K/Akt/mTOR pathway, providing a foundation for the mechanism research and treatment of gastric cancer.

MiR-361-5p inhibits glycolytic metabolism, proliferation and invasion of breast cancer by targeting FGFR1 and MMP-1

Background

MicroRNAs function as key regulators in various human cancers, including breast cancer (BC). MiR-361-5p has been proved to be a tumor suppressor in colorectal cancer and gastric cancer in our previous study. In this study, we aim to find out the function of miR-361-5p in breast cancer progression and elaborate the mechanism that miR-361-5p acts its function in breast cancer.

Methods and results

Here we reported that miR-361-5p was down-regulated in breast cancer tissue compared with normal breast tissue and the expression of miR-361-5p was positively associated with prognosis in BC patients. Functional studies showed that overexpression of miR-361-5p suppressed the proliferation, invasion and metastasis of breast cancer cells both in vivo and in vitro. Mechanistically, we found that miR-361-5p inhibited the proliferation of BC cells by suppressing glycolysis. FGFR1, a promoter of glycolysis-related enzyme, was identified as the target of miR-361-5p that promoted glycolysis and repressed oxidative phosphorylation. Furthermore, we demonstrated that miR-361-5p inhibited breast cancer cells invasion and metastasis by targeting MMP-1. An inverse expression pattern was also found between miR-361-5p and FGFR1 or MMP-1 in a cohort of 60 BC tissues.

Conclusion

Our results indicate that miR-361-5p inhibits breast cancer cells glycolysis and invasion by respectively repressing FGFR1 and MMP-1, suggesting that miR-361-5p and its targets may serve as therapeutic targets in breast cancer treatment.

MiR-26b reverses temozolomide resistance via targeting Wee1 in glioma cells

Emerging evidence has demonstrated that microRNAs (miRNA) play a critical role in chemotherapy-induced epithelial-mesenchymal transition (EMT) in glioma. However, the underlying mechanism of chemotherapy-triggered EMT has not been fully understood. In the current study, we determined the role of miR-26b in regulation of EMT in stable temozolomide (TMZ)-resistant (TR) glioma cells, which have displayed mesenchymal features. Our results illustrated that miR-26b was significantly downregulated in TR cells. Moreover, ectopic expression of miR-26b by its mimics reversed the phenotype of EMT in TR cells. Furthermore, we found that miR-26b governed TR-mediate EMT partly due to governing its target Wee1. Notably, overexpression of miR-26b sensitized TR cells to TMZ. These findings suggest that upregulation of miR-26b or targeting Wee1 could serve as novel approaches to reverse chemotherapy resistance in glioma.