MiR-27a regulates Wnt/beta-catenin signaling through targeting SFRP1 in glioma

Comprehensive analysis of distinct circadian clock subtypes of adult diffuse glioma and their associations with clinicopathological, genetic, and epigenetic profiles

The circadian clock (CC) has biological and clinical implications in gliomas. Most studies focused on CC effects on the tumor microenvironment and the application of chronotherapy. The present study focused on CC gene expression patterns and intracellular oncogenic activities. Glioma gene expression data were collected from The Human Cancer Genome Atlas (TCGA) project. After applying inclusion and exclusion criteria, we selected 666 patients from TCGA-GBM and TCGA-LGG projects and included important clinicopathological variables. The entire cohort was subjected to clustering analysis and divided into CC1 and CC2 subtypes based on statistical, biological, and clinical criteria. CC2 gliomas showed higher expression of BMAL1 and CRY1 and lower expression of CRY2 and PER2 (adjusted P < .001). CC2 gliomas had q higher activity of cell proliferation, metabolic reprogramming, angiogenesis, hypoxia, and many oncogenic signals (P < .001). The CC2 subtype contained a higher proportion of glioblastomas (P < .001) and had a worse prognosis (P < .001). Stratified Kaplan-Meier and multivariable Cox analyses illustrated that the CC subtype is an independent prognostic factor to clinicopathological characteristics (P < .001), genetic aberrations (P = .006), and biological processes (P < .001). Thus, this study shows statistical evidence of CC subtypes and their biological, and clinicopathological significance in adult gliomas.

The importance of the circRNA/Wnt axis in gliomas: Biological functions and clinical opportunities

Gliomas are among the most common cancers in the central nervous system, arising through various signaling pathways. One significant pathway is Wnt signaling, a tightly regulated process that plays a crucial role in gliomagenesis and development. The current study aims to explore the relationship between circular RNAs (circRNAs) and the Wnt/β-catenin signaling pathway in gliomas, considering the growing recognition of circRNAs in disease pathogenesis. A comprehensive review of recent research was conducted to investigate the roles of circRNAs in gliomas, focusing on their expression patterns and interactions with the Wnt signaling pathway. The analysis included studies examining circRNAs' function as microRNA sponges and their impact on glioma biology. The findings reveal that circRNAs are differentially expressed in gliomas and significantly influence the occurrence, growth, and metastasis of these tumors. Specifically, circRNAs interact with the Wnt signaling pathway, affecting glioma development and progression. This interaction highlights the importance of circRNAs in glioma pathophysiology. Understanding the regulatory network involving circRNAs and Wnt signaling offers valuable insights into glioma pathophysiology. CircRNAs hold promise as diagnostic and prognostic biomarkers and may serve as targets for novel therapeutic strategies in glioma treatment.

Regulatory role of miRNAs on Wnt/β-catenin signaling in tumorigenesis of glioblastoma

Glioblastoma (GBM) is one of the most aggressive tumors in the brain with high mortality worldwide. Despite recent advances in therapeutic strategies, the survival rate remains low in patients with GBM. The pathogenesis of GBM is a very complicated process involving various genetic mutations affecting several oncogenic signaling pathways like Wnt/β-catenin axis. Overactivation of the Wnt/β-catenin signaling pathway is associated with decreased survival and poor prognosis in patients with GBM. MicroRNAs (miRNAs) were shown to play important roles in the regulation of cell proliferation, differentiation, apoptosis, and tumorigenesis by modulating the expression of their target genes. Aberrant expression of miRNAs were reported in various human malignancies including GBM, breast, colorectal, liver, and prostate cancers, but little is known about their cellular mechanisms. Therefore, recognition of the expression profile and regulatory effects of miRNAs on the Wnt/β-catenin pathway may offer a novel approach for the classification, diagnosis, prognosis, and treatment of patients with GBM. This review summarizes previous data on the modulatory role of miRNAs on the Wnt/β-catenin pathway implicated in tumorigenesis of GBM.

Comparison of Oncogenes, Tumor Suppressors, and MicroRNAs Between Schizophrenia and Glioma: The Balance of Power

The risk of cancer in schizophrenia has been controversial. Confounders of the issue are cigarette smoking in schizophrenia, and antiproliferative effects of antipsychotic medications. The author has previously suggested comparison of a specific cancer like glioma to schizophrenia might help determine a more accurate relationship between cancer and schizophrenia. To accomplish this goal, the author performed three comparisons of data; the first a comparison of conventional tumor suppressors and oncogenes between schizophrenia and cancer including glioma. This comparison determined schizophrenia has both tumor-suppressive and tumor-promoting characteristics. A second, larger comparison between brain-expressed microRNAs in schizophrenia with their expression in glioma was then performed. This identified a core carcinogenic group of miRNAs in schizophrenia offset by a larger group of tumor-suppressive miRNAs. This proposed "balance of power" between oncogenes and tumor suppressors could cause neuroinflammation. This was assessed by a third comparison between schizophrenia, glioma and inflammation in asbestos-related lung cancer and mesothelioma (ALRCM). This revealed that schizophrenia shares more oncogenic similarity to ALRCM than glioma.

Marsdenia tenacissima extract prevents the malignant progression of glioma through upregulating lncRNA MEG3 and SFRP1-dependent inhibition of Wnt/β-catenin pathway

BACKGROUND/AIM

Recent studies have highlighted the tumor-suppressive effect of Marsdenia tenacissima extract (MTE) on human cancers. This research unveils the potential impact of MTE on glioma and ascertains the relevant molecular mechanisms.

METHODS

Glioma cells were treated with MTE, with normal human astrocytes (NHAs) as controls. A battery of function experiments, including the CCK-8 viability test, colony formation assay, scratch migration assay, and Transwell invasion assay, was executed to address the responses of glioma cells to MTE treatment and gain or loss of function of lncMEG3, miR-542-3p, and SFRP1. FISH, RIP, and dual-luciferase reporter assays were adopted for assessing gene interactions. U251-GFP-Luc cells were delivered into nude mice through intracranial injection to develop an orthotopic glioma model for in vivo validation.

RESULTS

200 mg/mL MTE could suppress the proliferating, migrating, and invading properties of glioma cells but not affect those of NHAs. MTE treatment enhanced the expression of lncMEG3, which competes with SFRP1 for binding miR-542-3p. SFRP1 could inactivate the Wnt/β-catenin pathway. Animal experimentation substantiated the antitumor activity and mechanism of MTE in nude mice.

CONCLUSIONS

MTE suppresses glioma via the lncMEG3/miR-542-3p/SFRP1/Wnt/β-catenin axis. These findings contribute to a theoretical basis for the use of MTE for glioma patients.

TCF3 Induces DNMT1 Expression to Regulate Wnt Signaling Pathway in Glioma

The epigenetic alteration is widely understood as the key to cancer initiation. Herein, we intended to clarify the role of transcription factor 3 (TCF3) in the development of glioma and the behind epigenetic mechanism. Through bioinformatics analysis, we identified a TCF3-DNA methyltransferase 1 (DNMT1)-secreted frizzled related protein 1 (SFRP1) axis which was differentially expressed and interacted in gliomas. More specifically, TCF3 activated DNMT1 transcription, and DNMT1 repressed SFRP1 expression. TCF3 and DNMT1 were overexpressed, while SFRP1 was downregulated in glioma. Functionally, TCF3 silencing inhibited cell proliferation and migration, and promoted apoptosis, which were reversed by DNMT1. SFRP1 inhibited the tumor supporting effects of DNMT1 on glioma cells. Moreover, TCF3 downregulation or SFRP1 overexpression inhibited tumorigenesis and enhanced apoptosis of glioma cells, while DNMT1 enhanced tumorigenesis and repressed apoptosis in tumor tissues in vivo. The Wnt pathway was a downstream effector of the TCF3-DNMT1-SFRP1 axis. Collectively, this study determined a novel therapeutic target TCF3 for glioma from the perspective of epigenetic alteration via regulation of SFRP1 expression in a DNMT1-dependent manner.

Regulatory interplay between microRNAs and WNT pathway in glioma

Glioma is one of the most common neoplasms of the central nervous system with a poor survival. Due to the obstacles in treating this disease, a part of recent studies mainly focuses on identifying the underlying molecular mechanisms that contribute to its malignancy. Altering microRNAs (miRNAs) expression pattern has been identified obviously in many cancers. Through regulating various targets and signaling pathways, miRNAs play a pivotal role in cancer progression. As one of the essential signaling pathways, WNT pathway is dysregulated in many cancers, and a growing body of evidence emphasis its dysregulation in glioma. Herein, we provide a comprehensive review of miRNAs involved in WNT pathway in glioma. Moreover, we show the interplay between miRNAs and WNT pathway in regulating different processes such as proliferation, invasion, migration, radio/chemotherapy resistance, and epithelial-mesenchymal-transition. Then, we introduce several drugs and treatments against glioma, which their effects are mediated through the interplay of WNT pathway and miRNAs.

Wnt/β-catenin signaling as an emerging potential key pharmacological target in cholangiocarcinoma

Cholangiocarcinoma (CCA) is a fatal malignant tumor of biliary epithelial cells involving intra- or extra-hepatic bile ducts. The prognosis of CCA is generally poor due to its diagnosis at the late stages. The currently employed chemotherapeutic agents do not increase the survival rate in patients with unresectable CCA. Accordingly, there is a need to identify new therapeutic agents for the effective management of intra- and extra-hepatic CCA. Clinical as well as preclinical studies have suggested the key role of the activation of Wnt/β-catenin signaling pathway in the induction and progression of CCA. There is an up-regulation of different Wnt ligands including Wnt2, Wnt3, Wnt5, Wnt7 and Wnt10 along with redistribution of β-catenin (more expression in the nucleus and lesser on the cell surface due to nuclear translocation of β-catenin) in different types of malignant biliary tumors. Apart from the role of this pathway in the induction and progression of CCA, this pathway is also involved in inducing multidrug resistance by inducing the expression of P-glycoprotein efflux pump on the cancer cells. These deleterious effects of Wnt/β-catenin signaling are mediated in association with other signaling pathways involving microRNAs (miRNAs), PI3K/AKT/PTEN/GSK-3β, retinoic acid receptors (RARs), dickkopf-1 (DKK1), protein kinase A regulatory subunit 1 α (PRKAR1A/PKAI), (SLAP), liver kinase B1 (LKB1) and CXCR4. The selective inhibitors of Wnt/β-catenin signaling may be potentially employed to overcome multidrug-resistant, fatal CCA. The present review discusses the role of Wnt/β-catenin along with its relation with other signaling pathways in the induction and progression of CCA.

MicroRNA-27a targets Sfrp1 to induce renal fibrosis in diabetic nephropathy by activating Wnt/β-Catenin signalling

Diabetic nephropathy (DN) commonly causes end-stage renal disease (ESRD). Increasing evidence indicates that abnormal miRNA expression is tightly associated with chronic kidney disease (CKD). This work aimed to investigate whether miR-27a can promote the occurrence of renal fibrosis in DN by suppressing the expression of secreted frizzled-related protein 1 (Sfrp1) to activate Wnt/β-catenin signalling. Therefore, we assessed the expression levels of miR-27a, Sfrp1, Wnt signalling components, and extracellular matrix (ECM)-related molecules in vitro and in vivo. Sfrp1 was significantly down-regulated in a high-glucose environment, while miR-27a levels were markedly increased. A luciferase reporter assay confirmed that miR-27a down-regulated Sfrp1 by binding to the 3′ untranslated region directly. Further, NRK-52E cells under high-glucose conditions underwent transfection with miR-27a mimic or the corresponding negative control, miR-27a inhibitor or the corresponding negative control, si-Sfrp1, or combined miR-27a inhibitor and si-Sfrp1. Immunoblotting and immunofluorescence were performed to assess the relative expression levels of Wnt/β-catenin signalling and ECM components. The mRNA levels of Sfrp1, miR-27a, and ECM-related molecules were also detected by quantitative real-time PCR (qPCR). We found that miR-27a inhibitor inactivated Wnt/β-catenin signalling and reduced ECM deposition. Conversely, Wnt/β-catenin signalling was activated, while ECM deposition was increased after transfection with si-Sfrp1. Interestingly, miR-27a inhibitor attenuated the effects of si-Sfrp1. We concluded that miR-27a down-regulated Sfrp1 and activated Wnt/β-catenin signalling to promote renal fibrosis.

Oncogenic miR-27a delivered by exosomes binds to SFRP1 and promotes angiogenesis in renal clear cell carcinoma

Exosomes derived from cancer cells have emerged as important mediators of malignant phenotypes of tumors, being involved in the transmission of biological signals between cells. Herein, we intended to clarify the role of exosome-mediated transfer of oncogenic microRNA-27a (miR-27a) in angiogenesis of renal clear cell carcinoma (RCCC). Through bioinformatics analysis, we identified the differentially expressed genes of RCCC and predicted miRNAs targeting SFRP1. We manipulated the expression of miR-27a and/or SFRP1 in RCCC cells to explore their roles in angiogenesis through Cell Counting Kit-8 (CCK-8), Transwell, and Matrigel tubule formation assays. miR-27a loaded in exosomes was overexpressed and downregulated in vitro and in vivo to verify its effect on angiogenesis. SFRP1 was poorly expressed and miR-27a was highly expressed in RCCC tissues, showing a negative correlation. Dual-luciferase assay verified that miR-27a targeted and downregulated SFRP1 expression. Notably, miR-27a enhanced angiogenesis by downregulating SFRP1 expression. miR-27a-loaded exosomes can be delivered from RCCC cells to human umbilical vein endothelial cells (HUVECs). In vitro and in vivo experiments substantiated that miR-27a-loaded exosomes from RCCC cells repressed SFRP1, augmenting the viability, migration, and angiogenesis of RCCC cells. Together, RCCC-derived miR-27a-loaded exosomes inhibit SFRP1 expression and accelerate tumor angiogenesis in RCCC.

Effects of long non-coding RNA (lncRNA) cancer susceptibility candidate 2c (CASC2c) on proliferation, metastasis and drug resistance of non-small cell lung cancer (NSCLC) cells through ERK1/2 and β-catenin signaling pathways

OBJECTIVES

This study was aimed to investigate the effects of long non-coding RNA (lncRNA) cancer susceptibility candidate 2c (CASC2c) on the proliferation, metastasis and drug resistance of non-small cell lung cancer (NSCLC) cells.

METHODS

The expression of CASC2c in NSCLC tissues and cell lines was detected by real-time fluorescence quantitative PCR (RT-qPCR). MTT and Transwell assay were used to determine the proliferation and migration of NSCLC cells in the experimental group and the control group respectively. The drug sensitivity test was used to confirm whether increasing the CASC2c expression level could reverse the resistance of NSCLC cells to the chemotherapy drug cisplatin. The effects of CASC2c on the expression levels of p-ERK1/2 and β-catenin were detected by western blot.

RESULTS

The results of RT-qPCR showed that CASC2c was under-expressed in NSCLC tissues and cells compared with normal adjacent lung tissues cells (p < 0.05). In addition, the CASC2c expression was remarkably correlated with TNM staging, tumor cell differentiation, lymph node metastasis, smoking and other pathological indicators of patients with NSCLC (p < 0.05). MTT and Transwell assay showed that the high-expression of CASC2c significantly reduced the proliferation and migration of NSCLC cells compared to that of the control group (p < 0.05). Western blot assay showed that the high-expressed CASC2c can decrease the expression of phosphorylated-ERK1/2 (p-ERK1/2) and β-catenin.

CONCLUSIONS

CASC2c was low expressed in NSCLC tissues and cells. What's more, it inhibited the proliferation and migration of NSCLC cells by inhibiting the expression of p-ERK1/2 and β-catenin and reversed NSCLC cells' resistance to the chemotherapy drug cisplatin. Therefore, CASC2c may serve as a new biomarker and therapeutic target in the diagnosis and treatment of NSCLC.

Silencing microRNA-27a inhibits proliferation and invasion of human osteosarcoma cells through the SFRP1-dependent Wnt/β-catenin signaling pathway

Osteosarcoma is the most common malignant tumor of bone with a high potential for metastasis. Importantly, microRNA-27a (miR-27a) is involved in the progression of osteosarcoma. The present study aims to discuss the effects of miR-27a and its target gene secreted frizzled related protein 1 (SFRP1) on proliferation and invasion of human osteosarcoma cells via Wnt/β-catenin signaling pathway. The expression of miR-27a and SFRP1 in osteosarcoma tissues and cells was detected, followed by identification of their relations. Subsequently, miR-27a mimic, miR-27a inhibitor, or siRNA against SFRP1 were introduced into cells (HOS and U2OS) to investigate their role in cell proliferation and invasion. The expression of Wnt/β-catenin signaling pathway-related gene was analyzed to further uncover the regulatory mechanism of miR-27a. The osteosarcoma tissues and cells exhibited elevated miR-27 expression and reduced SFRP1 expression. SFRP1 was verified to be a target gene of miR-27a. Meanwhile, silenced miR-27a inhibited proliferation and invasion of human osteosarcoma cells. Finally, silencing miR-27a inhibited the activation of Wnt/β-catenin signaling pathway, evidenced by reduced β-catenin expression. Our study draws a conclusion that silencing miR-27a dampens osteosarcoma progression, which might be achieved through the inactivation of the Wnt/β-catenin signaling pathway by up-regulating SFRP1.

Relationship between microRNA-27a and efficacy of neoadjuvant chemotherapy in gastric cancer and its mechanism in gastric cancer cell growth and metastasis

Objective: The aim of the present study is to investigate the relationship between microRNA-27a (miR-27a) and the efficacy of neoadjuvant chemotherapy in gastric cancer (GC) and its mechanism in the growth and metastasis of GC cells.

Methods: The expression of miR-27a in serum of 74 GC patients received neoadjuvant chemotherapy was detected by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). Clinical value and prognosis of miR-27a expression in predicting the efficacy of neoadjuvant chemotherapy in GC were evaluated. Besides, GC cells with low miR-27a expression were transfected with miR-27a mimics, and cells with high miR-27a expression were transfected with miR-27a inhibitors and secreted frizzled-related protein 1 (SFRP1) siRNA. A series of experiments were applied for the determination of cell viability, invasion and migration of GC cells.

Results: After neoadjuvant chemotherapy, the expression of miR-27a in serum of GC patients decreased significantly. Additionally, the expression of miR-27a in GC cell line was significantly higher than that in normal gastric mucosa cell line. Meanwhile, after down-regulating the expression of miR-27a in GC cells, the mRNA and protein expression of SFRP1 increased, the proliferation rate of cells slowed down, and the ability of invasion and migration decreased. Furthermore, combined with low expression of miR-27a and SFRP1, the proliferation rate of GC cells increased and the ability of invasion and migration increased.

Conclusion: Collectively, our study highlights that the high expression of miR-27a indicates the poor efficacy and prognosis of neoadjuvant chemotherapy in GC patients. Down-regulation of miR-27a can inhibit the growth and metastasis of GC cells via up-regulation of SFRP1.

Down-regulation of microRNA-31-5p inhibits proliferation and invasion of osteosarcoma cells through Wnt/β-catenin signaling pathway by enhancing AXIN1

OBJECTIVES

Recently, the role of microRNA-31-5p (miR-31-5p) in gene expression regulation has been reported in various cancers. Studies have shown that Wnt/β-catenin signaling pathway is involved in the proliferation and invasion of osteosarcoma (OS) cells. Therefore, this study aims to probe into the regulatory role of miR-31-5p targeting AXIN1 in OS cells through Wnt/β-catenin signaling pathway.

METHODS

Firstly, microarray expression profiles were used to screen differentially expressed miRNAs associated with OS. Next, OS and normal fibrous connective tissues as well as OS cell lines were obtained for investigating the role of miR-31-5p on OS. Then, the putative binding sites between miR-31-5p and AXIN1 were predicted and verified. The regulatory effects of miR-31-5p on proliferation and invasion as well as tumorigenic potential of OS cells targeting AXIN1 were also analyzed. Besides, the relationship between miR-31-5p and Wnt/β-catenin signaling pathway was assessed by immunofluorescence staining.

RESULTS

The microarray dataset GSE63939 showed that miR-31-5p and AXIN1 were involved in OS. miR-31-5p expression increased while the expression of AXIN1 decreased in OS tissues and cells. AXIN1 was identified as a target gene of miR-31-5p, intense expression of which inhibited the transcription of AXIN1. Down-regulated miR-31-5p suppressed proliferation, invasion and tumorigenicity of OS cells through promoting AXIN1. Decreased miR-31-5p activated Wnt/β-catenin signaling pathway, as reflected by increased β-catenin translocation into nuclei, through up-regulating the transcription of AXIN1.

CONCLUSIONS

All in all, repression of miR-31-5p targets AXIN1 to activate the Wnt/β-catenin signaling pathway, thus suppressing proliferation, invasion and tumorigenicity of OS cells.

miR-370 Sensitizes TMZ Response Dependent of MGMT Status in Primary Central Nervous System Lymphoma

Primary central nervous system lymphoma (PCNSL) is an aggressive and rare subtype of non-Hodgkin lymphoma, arising exclusively in the CNS with a poor prognosis. Previous evidence has proved that MGMT was a promising target involving in TMZ resistance of PCNSL. Our study described a new miR-370-mediated mechanism of MGMT regulation in PCNSL. We first showed that miR-370 was downregulated in PCNSL tissues, while MGMT was inversely overexpressed. It was also observed that miR-370 suppressed the expression of MGMT. Additionally, upregulation of miR-370 significantly increased TMZ sensitivity dependent of MGMT, thus suppressed Raji cell proliferation and induced apoptosis in vitro. In conclusion, these results suggest that miR-370 is a potential target in PCNSL treatment.

Retracted: Inhibition of microRNA-940 suppresses the migration and invasion of human osteosarcoma cells through the secreted frizzled-related protein 1-mediated Wnt/β-catenin signaling pathway

Osteosarcoma (OS) is the most common malignant tumor of bone with a high potential for metastasis. This study intends to explore whether microRNA-940 (miR-940) affects the development of OS cells and the underlying mechanism. OS and adjacent normal tissues were collected from OS patients; the OS cell line with the highest expression of miR-940 was selected, which was then subjected to transfection of miR-940 mimic, miR-940 inhibitor, siRNA-secreted frizzled-related protein 1 (SFRP1) or LiCl (agonists of Wnt/β-catenin pathway) to identify regulation of miR-940 to OS cells through SFRP1. The targeting relationship between miR-940 and SFRP1 was verified using dual-luciferase reporter gene assay. Reverse-transcription quantitative polymerase chain reaction and Western blot assay were performed to determine miR-940, SFRP1, β-catenin, and cyclinD1 and apoptosis-related genes Fas, Bax, and Bcl-2. MTT (3-(4, 5-dimethylthiazol-2-Yl)-2, 5-diphenyltetrazolium bromide) assay, scratch test, transwell assay, and flow cytometry were carried out to detect proliferation, migration, invasion, and apoptosis, respectively. Nude mice models were established to observe the tumor formation. Higher expression of miR-940, β-catenin, and cyclinD1 and lower SFRP1 expression were identified in OS tissues. miR-940 targeted and negatively regulated SFRP1 expression. Furthermore, upregulated miR-940 expression activated the Wnt/β-catenin signaling pathway in OS. With the treatment of miR-940 mimic, LiCL, or siRNA-SFRP1, OS cells showed promoted proliferation, migration, invasion, tumor formation, and impeded apoptosis (further reflected by elevated Bcl-2 expression and reduced Fas and Bax expression). The study demonstrates that miR-940 can promote the proliferation, migration, and invasion but suppress the apoptosis of human OS cells by downregulating SFRP1 through activating Wnt/β-catenin signaling pathway.

Obesity-associated miR-27a upregulation promotes hepatocellular carcinoma metastasis through suppressing SFRP1

Background

Obesity was a recognized risk factor for the development and progression of hepatocellular carcinoma (HCC). However, the effects and mechanisms by which obesity promotes HCC metastasis remain poorly understood.

Materials and methods

We cultured adipocyte induced by preadipocyte 3T3-L1 in vitro and established HCC metastasis model in obesity mouse in vivo to mimic the tumor microenvironment in obese status. The mechanisms underlying obesity-associated miR-27a upregulation promoting HCC metastasis were investigated.

Results

In this study, we showed that miR-27a was upregulated in adipocytes, obese mouse model and clinical samples, and the increased miR-27a level promoted migration and invasion in HCC cells, increased the number of metastasis nodes in obese mouse model, and was associated with poor clinical outcomes. Overexpressed secreted frizzled-related protein 1 in HCC cells and tissues significantly alleviated the upregulation of β-catenin and matrix metalloproteinase-7 induced by high level of miR-27a. Meanwhile, the E-cadherin expression decreased and Vimentin expression increased, linking with high level of β-catenin in high-fat group.

Conclusion

Taken together, our results have elucidated the critical role of extracellular miR-27a as a pro-metastatic factor in HCC and revealed that obesity-associated miR-27a upregulation promoted HCC metastasis through activated Wnt/β-catenin signaling by suppressing secreted frizzled-related protein 1. Our findings shed light on the novel mechanism underlying HCC metastasis and provided miR-27a as a promising target for obese liver cancer therapy.

MicroRNA-target cross-talks: Key players in glioblastoma multiforme

The role of microRNAs in brain cancer is still naive. Some act as oncogene and others as tumor suppressors. Discovery of efficient biomarkers is mandatory to debate that aggressive disease. Bioinformatically selected microRNAs and their targets were investigated to evaluate their putative signature as diagnostic and prognostic biomarkers in primary glioblastoma multiforme. Expression of a panel of seven microRNAs (hsa-miR-34a, hsa-miR-16, hsa-miR-17, hsa-miR-21, hsa-miR-221, hsa-miR-326, and hsa-miR-375) and seven target genes ( E2F3, PI3KCA, TOM34, WNT5A, PDCD4, DFFA, and EGFR) in 43 glioblastoma multiforme specimens were profiled compared to non-cancer tissues via quantitative reverse transcription-polymerase chain reaction. Immunohistochemistry staining for three proteins (VEGFA, BAX, and BCL2) was performed. Gene enrichment analysis identified the biological regulatory functions of the gene panel in glioma pathway. MGMT ( O-6-methylguanine-DNA methyltransferase) promoter methylation was analyzed for molecular subtyping of tumor specimens. Our data demonstrated a significant upregulation of five microRNAs (hsa-miR-16, hsa-miR-17, hsa-miR-21, hsa-miR-221, and hsa-miR-375), three genes ( E2F3, PI3KCA, and Wnt5a), two proteins (VEGFA and BCL2), and downregulation of hsa-miR-34a and three other genes ( DFFA, PDCD4, and EGFR) in brain cancer tissues. Receiver operating characteristic analysis revealed that miR-34a (area under the curve = 0.927) and miR-17 (area under the curve = 0.900) had the highest diagnostic performance, followed by miR-221 (area under the curve = 0.845), miR-21 (area under the curve = 0.836), WNT5A (area under the curve = 0.809), PDCD4 (area under the curve = 0.809), and PI3KCA (area under the curve = 0.800). MGMT promoter methylation status was associated with high miR-221 levels. Moreover, patients with VEGFA overexpression and downregulation of TOM34 and BAX had poor overall survival. Nevertheless, miR-17, miR-221, and miR-326 downregulation were significantly associated with high recurrence rate. Multivariate analysis by hierarchical clustering classified patients into four distinct groups based on gene panel signature. In conclusion, the explored microRNA-target dysregulation could pave the road toward developing potential therapeutic strategies for glioblastoma multiforme. Future translational and functional studies are highly recommended to better understand the complex bio-molecular signature of this difficult-to-treat tumor.

In vivo and in vitro effects of microRNA-27a on proliferation, migration and invasion of breast cancer cells through targeting of SFRP1 gene via Wnt/β-catenin signaling pathway

This study aims to explore the effects of microRNA-27a (miR-27a) targeting of SFRP1 on the proliferation, migration and invasion of breast cancer (BC) cells through the regulation of Wnt/β-catenin signaling pathway. BC and normal breast tissues were obtained from 396 female BC patients and 308 female patients with benign breast lesions respectively. Human normal mammary epithelial (MCF-10A) and BC cell lines (BT-20, MCF-7, T-47D and MDA-MB-231) were cultured. After cell transfection, BC cells were assigned to six groups: control, miR-27a mimics, miR-27a inhibitors, negative control (NC), si-SFRP1 and si-SFRP1 + miR-27a inhibitors groups. qRT-PCR assay and Western blot were employed to detect the expressions of miR-27a, SFRP1, Wnt, β-catenin and GSK3β. MTT assay, wound-healing test and Transwell assay were used to test cell proliferation, migration and invasion. BC tissues were found to have higher miR-27a expression and lower SFRP1 mRNA and protein expressions than MCF-10A cells and normal breast tissues. Compared with the control and NC groups, the miR-27a mimics and si-SFRP1 groups exhibited down-regulation of SFRP1, up-regulation of Wnt, β-catenin and GSK3β, and promotion of cell proliferation, migration and invasion. The miR-27a inhibitor group showed up-regulation of SFRP1 and inhibition of cell proliferation, migration and invasion in comparison to the miR-27a mimic group. The si-SFRP1 + miR-27a inhibitors group also exhibited up-regulation of SFRP1 and inhibition of cell proliferation, migration and invasion in comparison to the si-SFRP1 group. miR-27a may activate the Wnt/β-catenin signaling pathway by negatively regulating SFRP1 to promote the proliferation, migration and invasion of BC cells.

Characterization of Lgr5+ Progenitor Cell Transcriptomes after Neomycin Injury in the Neonatal Mouse Cochlea

Lgr5+ supporting cells (SCs) are enriched hair cell (HC) progenitors in the cochlea. Both in vitro and in vivo studies have shown that HC injury can spontaneously activate Lgr5+ progenitors to regenerate HCs in the neonatal mouse cochlea. Promoting HC regeneration requires the understanding of the mechanism of HC regeneration, and this requires knowledge of the key genes involved in HC injury-induced self-repair responses that promote the proliferation and differentiation of Lgr5+ progenitors. Here, as expected, we found that neomycin-treated Lgr5+ progenitors (NLPs) had significantly greater HC regeneration ability, and greater but not significant proliferation ability compared to untreated Lgr5+ progenitors (ULPs) in response to neomycin exposure. Next, we used RNA-seq analysis to determine the differences in the gene-expression profiles between the transcriptomes of NLPs and ULPs from the neonatal mouse cochlea. We first analyzed the genes that were enriched and differentially expressed in NLPs and ULPs and then analyzed the cell cycle genes, the transcription factors, and the signaling pathway genes that might regulate the proliferation and differentiation of Lgr5+ progenitors. We found 9 cell cycle genes, 88 transcription factors, 8 microRNAs, and 16 cell-signaling pathway genes that were significantly upregulated or downregulated after neomycin injury in NLPs. Lastly, we constructed a protein-protein interaction network to show the interaction and connections of genes that are differentially expressed in NLPs and ULPs. This study has identified the genes that might regulate the proliferation and HC regeneration of Lgr5+ progenitors after neomycin injury, and investigations into the roles and mechanisms of these genes in the cochlea should be performed in the future to identify potential therapeutic targets for HC regeneration.

Wnt5a Drives an Invasive Phenotype in Human Glioblastoma Stem-like Cells

Brain invasion by glioblastoma determines prognosis, recurrence, and lethality in patients, but no master factor coordinating the invasive properties of glioblastoma has been identified. Here we report evidence favoring such a role for the noncanonical WNT family member Wnt5a. We found the most invasive gliomas to be characterized by Wnt5a overexpression, which correlated with poor prognosis and also discriminated infiltrating mesenchymal glioblastoma from poorly motile proneural and classical glioblastoma. Indeed, Wnt5a overexpression associated with tumor-promoting stem-like characteristics (TPC) in defining the character of highly infiltrating mesenchymal glioblastoma cells (Wnt5a^High). Inhibiting Wnt5a in mesenchymal glioblastoma TPC suppressed their infiltrating capability. Conversely, enforcing high levels of Wnt5a activated an infiltrative, mesenchymal-like program in classical glioblastoma TPC and Wnt5a^Low mesenchymal TPC. In intracranial mouse xenograft models of glioblastoma, inhibiting Wnt5a activity blocked brain invasion and increased host survival. Overall, our results highlight Wnt5a as a master regulator of brain invasion, specifically TPC, and they provide a therapeutic rationale to target it in patients with glioblastoma. Cancer Res; 77(4); 996-1007. ©2016 AACR.

MicroRNA-27a Negatively Modulates the Inflammatory Response in Lipopolysaccharide-Stimulated Microglia by Targeting TLR4 and IRAK4

microRNA, a family of small non-coding RNA, plays significant roles in regulating gene expression, mainly via binding to the 3'-untranslated region of target genes. Although the role of miRNA in regulating neuroinflammation via the innate immune pathway has been studied, its role in the production of inflammatory mediators during microglial activation is poorly understood. In this study, we investigated the effect of miR-27a on lipopolysaccharide (LPS)-induced microglial inflammation. miR-27a expression was found to be rapidly decreased in microglia by real-time polymerase chain reaction (real-time PCR) after LPS stimulation. Over-expression of miR-27a significantly decreased the production of inflammatory cytokines, such as interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and nitric oxide (NO), whereas knockdown of miR-27a increased the expression of these inflammatory factors. We also demonstrated by loss- and gain-of-function studies that miR-27a directly suppressed the expression of toll-like receptor 4 (TLR4) and interleukin-1 receptor-associated kinase 4 (IRAK4)-a pivotal adaptor kinase in the TLR4/MyD88 signaling pathway-by directly binding their 3'-UTRs: knocking down TLR4 or IRAK4 in microglia significantly decreased TLR4 or IRAK4 expression and inhibited the downstream production of inflammatory mediators. Moreover, the inflammatory cytokines IL-6 and IL-1β were regulated by IRAK4, whereas TNF-α and NO were more dependent on TLR4 activation. Thus, miR-27a might regulate the LPS-induced production of inflammatory cytokines in microglia independently of TLR4 and IRAK4. Taken together, our results suggest that miR-27a is associated with microglial activation and the inflammatory response.