miR-124 suppresses glioblastoma growth and potentiates chemosensitivity by inhibiting AURKA

Aurora kinase A inhibition plus Tumor Treating Fields suppress glioma cell proliferation in a cilium-independent manner

Tumor Treating Fields (TTFields) extend the survival of glioblastoma (GBM) patients by interfering with a broad range of tumor cellular processes. Among these, TTFields disrupt primary cilia stability on GBM cells. Here we asked if concomitant treatment of TTFields with other agents that interfere with GBM ciliogenesis further suppress GBM cell proliferation in vitro. Aurora kinase A (AURKA) promotes both cilia disassembly and GBM growth. Inhibitors of AURKA, such as Alisertib, inhibit cilia disassembly and increase ciliary frequency in various cell types. However, we found that Alisertib treatment significantly reduced GBM cilia frequency in gliomaspheres across multiple patient derived cell lines, and in patient biopsies treated ex vivo. This effect appeared glioma cell-specific as it did not reduce normal neuronal or glial cilia frequencies. Alisertib-mediated depletion of glioma cilia appears specific to AURKA and not AURKB inhibition, and attributable in part to autophagy pathway activation. Treatment of two different GBM patient-derived cell lines with TTFields and Alisertib resulted in a significant reduction in cell proliferation compared to either treatment alone. However, this effect was not cilia-dependent as the combined treatment reduced proliferation in cilia-depleted cell lines lacking, ARL13B, or U87MG cells which are naturally devoid of ARL13B+ cilia. Thus, Alisertib-mediated effects on glioma cilia may be a useful biomarker of drug efficacy within tumor tissue. Considering Alisertib can cross the blood brain barrier and inhibit intracranial growth, our data warrant future studies to explore whether concomitant Alisertib and TTFields exposure prolongs survival of brain tumor-bearing animals in vivo.

Use of microRNAs as Diagnostic, Prognostic, and Therapeutic Tools for Glioblastoma

Glioblastoma (GB) is the most aggressive and common type of cancer within the central nervous system (CNS). Despite the vast knowledge of its physiopathology and histology, its etiology at the molecular level has not been completely understood. Thus, attaining a cure has not been possible yet and it remains one of the deadliest types of cancer. Usually, GB is diagnosed when some symptoms have already been presented by the patient. This diagnosis is commonly based on a physical exam and imaging studies, such as computed tomography (CT) and magnetic resonance imaging (MRI), together with or followed by a surgical biopsy. As these diagnostic procedures are very invasive and often result only in the confirmation of GB presence, it is necessary to develop less invasive diagnostic and prognostic tools that lead to earlier treatment to increase GB patients' quality of life. Therefore, blood-based biomarkers (BBBs) represent excellent candidates in this context. microRNAs (miRNAs) are small, non-coding RNAs that have been demonstrated to be very stable in almost all body fluids, including saliva, serum, plasma, urine, cerebrospinal fluid (CFS), semen, and breast milk. In addition, serum-circulating and exosome-contained miRNAs have been successfully used to better classify subtypes of cancer at the molecular level and make better choices regarding the best treatment for specific cases. Moreover, as miRNAs regulate multiple target genes and can also act as tumor suppressors and oncogenes, they are involved in the appearance, progression, and even chemoresistance of most tumors. Thus, in this review, we discuss how dysregulated miRNAs in GB can be used as early diagnosis and prognosis biomarkers as well as molecular markers to subclassify GB cases and provide more personalized treatments, which may have a better response against GB. In addition, we discuss the therapeutic potential of miRNAs, the current challenges to their clinical application, and future directions in the field.

Tumor-specific polycistronic miRNA delivered by engineered exosomes for the treatment of glioblastoma

BACKGROUND

Glioblastoma (GBM) has poor prognosis due to ineffective agents and poor delivery methods. MicroRNAs (miRs) have been explored as novel therapeutics for GBM, but the optimal miRs and the ideal delivery strategy remain unresolved. In this study, we sought to identify the most effective pan-subtype anti-GBM miRs and to develop an improved delivery system for these miRs.

METHODS

We conducted an unbiased screen of over 600 miRs against 7 glioma stem cell (GSC) lines representing all GBM subtypes to identify a set of pan-subtype-specific anti-GBM miRs and then used available TCGA GBM patient outcomes and miR expression data to hone in on miRs that were most likely to be clinically effective. To enhance delivery and expression of the miRs, we generated a polycistronic plasmid encoding 3 miRs (pPolymiR) and used HEK293T cells as biofactories to package pPolymiR into engineered exosomes (eExos) that incorporate viral proteins (Gag/VSVg) in their structure (eExos+pPolymiR) to enhance function.

RESULTS

Our stepwise screen identified miR-124-2, miR-135a-2, and let-7i as the most effective miRs across all GBM subtypes with clinical relevance. Delivery of eExos+pPolymiR resulted in high expression of all 3 miRs in GSCs, and significantly decreased GSC proliferation in vitro. eExos+pPolymiR prolonged survival of GSC-bearing mice in vivo when compared with eExos carrying each of the miRs individually or as a cocktail.

CONCLUSION

eExos+pPolymiR, which includes a pan-subtype anti-glioma-specific miR combination encoded in a polycistronic plasmid and a novel exosome delivery platform, represents a new and potentially powerful anti-GBM therapeutic.

Use of cutting-edge RNA-sequencing technology to identify biomarkers and potential therapeutic targets in canine and feline cancers and other diseases

With the growing interest in companion animals and the rapidly expanding animal healthcare and pharmaceuticals market worldwide. With the advancements in RNA-sequencing (RNA-seq) technology, it has become a valuable tool for understanding biological processes in companion animals and has multiple applications in animal healthcare. Historically, veterinary diagnoses and treatments relied solely on clinical symptoms and drugs used in human diseases. However, RNA-seq has emerged as an effective technology for studying companion animals, providing insights into their genetic information. The sequencing technology has revealed that not only messenger RNAs (mRNAs) but also non-coding RNAs (ncRNAs) such as long ncRNAs and microRNAs can serve as biomarkers. Based on the examination of RNA-seq applications in veterinary medicine, particularly in dogs and cats, this review concludes that RNA-seq has significant potential as a diagnostic and research tool. It has enabled the identification of potential biomarkers for cancer and other diseases in companion animals. Further research and development are required to maximize the utilization of RNA-seq for improved disease diagnosis and therapeutic targeting in companion animals.

MicroRNA (miR)-124: A Promising Therapeutic Gateway for Oncology

MicroRNA (miR) are a class of small non-coding RNA that are involved in post-transcriptional gene regulation. Altered expression of miR has been associated with several pathological conditions. MicroRNA-124 (miR-124) is an abundantly expressed miR in the brain as well as the thymus, lymph nodes, bone marrow, and peripheral blood mono-nuclear cells. It plays a key role in the regulation of the host immune system. Emerging studies show that dysregulated expression of miR-124 is a hallmark in several cancer types and it has been attributed to the progression of these malignancies. In this review, we present a comprehensive summary of the role of miR-124 as a promising therapeutic gateway in oncology.

The CNS-penetrating taxane drug TPI 287 potentiates antiglioma activity of the AURKA inhibitor alisertib in vivo

INTRODUCTION

Glioblastoma (GBM) has a very poor prognosis despite current treatment. We previously found cytotoxic synergy between the AURKA inhibitor alisertib and the CNS-penetrating taxane TPI 287 against GBM tumor cells in vitro.

METHODS

We used an orthotopic human GBM xenograft mouse model to test if TPI 287 potentiates alisertib in vivo. Western blotting, immunohistochemistry, siRNA knockdown, annexin V binding, and 3-dimensional Matrigel invasion assays were used to investigate potential mechanisms of alisertib and TPI 287 treatment interactions.

RESULTS

Alisertib + TPI 287 combination therapy significantly prolonged animal survival compared to vehicle (p = 0.011), but only marginally compared to alisertib alone. Alisertib, TPI 287, and combined alisertib + TPI 287 reduced animal tumor volume compared to vehicle-treated controls. This was statistically significant for the combination therapy at 4 weeks (p < 0.0001). Alisertib + TPI 287 treatment decreased anti-apoptotic Bcl-2 protein levels in vivo and in vitro. Expression of the pro-apoptotic protein Bak was significantly increased by combination treatment (p < 0.0001). Pro-apoptotic Bim and Bak knockdown by siRNA decreased apoptosis by alisertib + TPI 287 in GB9, GB30, and U87 cells (p = 0.0005 to 0.0381). Although alisertib and TPI 287 significantly reduced GBM cell invasion (p < 0.0001), their combination was no more effective than TPI 287 alone.

CONCLUSIONS

Results suggest that apoptosis is the dominant mechanism of potentiation of GBM growth inhibition by alisertib + TPI 287, in part through effects on Bcl-2 family proteins, providing a rationale for further laboratory testing of an AURKA inhibitor plus TPI 287 as a potential therapy against GBM.

The Role of microRNAs in Multidrug Resistance of Glioblastoma

Simple Summary

Glioblastoma (GBM) is one of the most malignant types of central nervous system tumor which accounts for more than 60% of all brain tumors in adults. Owing to poor prognosis and drug resistance of most GBM, it is urged to further develop the diagnosis and treatment strategies. The aim of this article is to highlight the roles of some functional microRNAs in the diagnosis and treatment of drug-resistant GBM. Besides, we suggest effective treatment strategies based on the expression profiles of these effective miRNAs to provide an alternative solution to deal with this cancer.

Abstract

Glioblastoma (GBM) is an aggressive brain tumor that develops from neuroglial stem cells and represents a highly heterogeneous group of neoplasms. These tumors are predominantly correlated with a dismal prognosis and poor quality of life. In spite of major advances in developing novel and effective therapeutic strategies for patients with glioblastoma, multidrug resistance (MDR) is considered to be the major reason for treatment failure. Several mechanisms contribute to MDR in GBM, including upregulation of MDR transporters, alterations in the metabolism of drugs, dysregulation of apoptosis, defects in DNA repair, cancer stem cells, and epithelial–mesenchymal transition. MicroRNAs (miRNAs) are a large class of endogenous RNAs that participate in various cell events, including the mechanisms causing MDR in glioblastoma. In this review, we discuss the role of miRNAs in the regulation of the underlying mechanisms in MDR glioblastoma which will open up new avenues of inquiry for the treatment of glioblastoma.

Determining KLF14 tertiary structure and diagnostic significance in brain cancer progression

Expression analysis of new protein targets may play a crucial role in the early detection and diagnosis of brain tumor progression. The study aimed to investigate the possible relation of KLF14, TPD52, miR-124, and PKCε in the development and progression of brain cancer and space occupying lesion (SOL) of the brain. One hundred human blood samples comprising varying diagnostic groups (SOL brain, grade I, II, III, IV) were analyzed by real-time quantitative PCR to determine the expression level of KLF14, TPD52, miR-124, and PKCε. TPD52 and PKCε were upregulated in brain cancer by 2.5- and 1.6-fold, respectively, whereas, KLF14 and miR-124 were downregulated in brain cancer. In metastatic and high-grade brain cancer, TPD52 and PKCε expression were up-regulated and KLF14 and miR-124 expression were down-regulated. Further, these genes were found to be differentially expressed in the blood of patients with SOL. Upregulation of TPD52 and PKCε, however, reduced expression of KLF14 and miR-124 in SOL of the brain as compared to healthy controls. Expression analysis of TPD52, KLF14, miR-124, and PKCε provided useful information on the differences existing between the normal brain and SOL, in addition to gliomas; thus, might prove to be useful having diagnostic or prognostic value.

In Vivo miRNA Decoy Screen Reveals miR-124a as a Suppressor of Melanoma Metastasis

Melanoma is a highly prevalent cancer with an increasing incidence worldwide and high metastatic potential. Brain metastasis is a major complication of the disease, as more than 50% of metastatic melanoma patients eventually develop intracranial disease. MicroRNAs (miRNAs) have been found to play an important role in the tumorigenicity of different cancers and have potential as markers of disease outcome. Identification of relevant miRNAs has generally stemmed from miRNA profiling studies of cells or tissues, but these approaches may have missed miRNAs with relevant functions that are expressed in subfractions of cancer cells. We performed an unbiased in vivo screen to identify miRNAs with potential functions as metastasis suppressors using a lentiviral library of miRNA decoys. Notably, we found that a significant fraction of melanomas that metastasized to the brain carried a decoy for miR-124a, a miRNA that is highly expressed in the brain/neurons. Additional loss- and gain-of-function in vivo validation studies confirmed miR-124a as a suppressor of melanoma metastasis and particularly of brain metastasis. miR-124a overexpression did not inhibit tumor growth in vivo, underscoring that miR-124a specifically controls processes required for melanoma metastatic growth, such as seeding and growth post-extravasation. Finally, we provide proof of principle of this miRNA as a promising therapeutic agent by showing its ability to impair metastatic growth of melanoma cells seeded in distal organs. Our efforts shed light on miR-124a as an antimetastatic agent, which could be leveraged therapeutically to impair metastatic growth and improve patient survival.

Epi-miRNAs: Regulators of the Histone Modification Machinery in Human Cancer

Cancer is a leading cause of death and disability worldwide. Epigenetic deregulation is one of the most critical mechanisms in carcinogenesis and can be classified into effects on DNA methylation and histone modification. MicroRNAs are small noncoding RNAs involved in fine-tuning their target genes after transcription. Various microRNAs control the expression of histone modifiers and are involved in a variety of cancers. Therefore, overexpression or downregulation of microRNAs can alter cell fate and cause malignancies. In this review, we discuss the role of microRNAs in regulating the histone modification machinery in various cancers, with a focus on the histone-modifying enzymes such as acetylases, deacetylases, methyltransferases, demethylases, kinases, phosphatases, desumoylases, ubiquitinases, and deubiquitinases. Understanding of microRNA-related aberrations underlying histone modifiers in pathogenesis of different cancers can help identify novel therapeutic targets or early detection approaches that allow better management of patients or monitoring of treatment response.

AURKA gene polymorphisms and central nervous system tumor susceptibility in Chinese children

INTRODUCTION

Central nervous system (CNS) tumors comprise 15-20% of all malignancies occurring in childhood and adolescence. Previous researches have shown that overexpression and amplification of the AURKA gene could induce multiple human malignancies, with which the connection of CNS tumor susceptibility has not been extensively studied.

MATERIAL AND METHODS

In this study, we assessed whether and to what extent AURKA gene single nucleotide polymorphisms (SNPs) (rs1047972 C > T, rs2273535 T > A, rs8173 G > C) were associated with CNS tumor susceptibility, based on a case-control analysis in 191 CNS tumor patients and 248 controls. We determined this correlation using odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

AURKA gene rs8173 G > C exhibited a crucial function to CNS tumor susceptibility fall-off (GC/CC vs. GG: adjusted OR = 0.68, 95% CI = 0.46-0.998, P = 0.049). In addition, the combined effect of lowering the risk of developing CNS tumors was more pronounced in carriers with 3 protective genotypes than others (adjusted OR = 0.55, 95% CI = 0.31-0.98, P = 0.044). Further stratification analysis illustrated that the existence of rs8173 GC/CC and three protective genotypes lowered CNS tumor risk in some subgroups.

CONCLUSIONS

Our research suggested that the AURKA gene rs8173 G > C could significantly reduce CNS tumor susceptibility in Chinese children. More functional experiments are needed to explore the role of the AURKA gene rs8173 G > C.

Tumor Suppressive Effects of miR-124 and Its Function in Neuronal Development

MicroRNA-124 (miR-124) is strongly expressed in neurons, and its expression increases as neurons mature. Through DNA methylation in the miR-124 promoter region and adsorption of miR-124 by non-coding RNAs, miR-124 expression is known to be reduced in many cancer cells, especially with high malignancy. Recently, numerous studies have focused on miR-124 due to its promising tumor-suppressive effects; however, the overview of their results is unclear. We surveyed the tumor-suppressive effect of miR-124 in glial cell lineage cancers, which are the most frequently reported cancer types involving miR-124, and in lung, colon, liver, stomach, and breast cancers, which are the top five causes of cancer death. Reportedly, miR-124 not only inhibits proliferation and accelerates apoptosis, but also comprehensively suppresses tumor malignant transformation. Moreover, we found that miR-124 exerts its anti-tumor effects by regulating a wide range of target genes, most notably STAT3 and EZH2. In addition, when compared to the original role of miR-124 in neuronal development, we found that the miR-124 target genes that contribute to neuronal maturation share similarities with genes that cause cancer cell metastasis and epithelial-mesenchymal transition. We believe that the two apparently unrelated fields, cancer and neuronal development, can bring new discoveries to each other through the study of miR-124.

An update on the role of miR-124 in the pathogenesis of human disorders

MicroRNA-124 (miR-124) is a copious miRNA in the brain, but it is expressed in a wide range of human/animal tissues participating in the pathogenesis of several disorders. Based on its important function in the development of the nervous system, abnormal expression of miR-124 has been detected in nervous system diseases including Alzheimer's disease, Parkinson's disease, Hypoxic-Ischemic Encephalopathy, Huntington's disease, and ischemic stroke. In addition to these conditions, miR-124 contributes to the pathogenesis of cardiovascular disorders, hypertension, and atherosclerosis. Besides, it has been shown to be down-regulated in a wide range of human cancers such as colorectal cancer, breast cancer, gastric cancer, glioma, pancreatic cancer, and other types of cancer. Yet, few studies have reported upregulation of miR-124 in some cancer types. In the current study, we describe the role of miR-124 in these malignant and non-malignant conditions.

Transcriptome analysis evinces anti-neoplastic mechanisms of hypericin: A study on U87 glioblastoma cell line

AIMS

Hypericin (HYP) from Hypericum perforatum has cytotoxic effects on a variety of malignant cell types, but the pattern of gene expression mediating the effect is largely unknown. Here we sought to analyze the response of U87 glioblastoma (GBM) cell lines in response to HYP.

MATERIALS AND METHODS

U87 cell line was treated by HYP. Cytotoxicity was assessed using MTT and Annexin V/PI assays. Gene expression profile was obtained using high-throughput sequencing. Enrichment analysis was performed on differentially expressed genes (DEGs). Upstream transcription factors and microRNAs regulating DEGs were predicted. The effects of DEGs on survival of GBM patients were calculated. Protein-protein interaction analysis was conducted to obtain key altered genes. The possible effect of HYP treatment on immunity response was evaluated.

KEY FINDINGS

The IC50 of HYP on U87 cell line was determined to be 1.5 μg/ml. The main type of cell death was apoptosis. A total of 312 DEGs were found. Affected Gene Ontology terms and pathways were identified. Analysis of upstream modulators of DEGs pointed out to transcription factors that significantly overlap with GBM stem cell transcription factor. Survival analysis suggested that HYP works best for the mesenchymal subtype patients. Tumor infiltration analysis predicted that HYP may affect Treg and macrophage infiltration in vivo. Using expression pattern of GBM patients and HYP-induced DEGs we suggested Fedratinib as a complementary drug to HYP.

SIGNIFICANCE

Our study represents the response of U87 cell line to HYP, with analyses on survival, transcription factors and personalization according to GBM subtype.

Disentangling the therapeutic tactics in GBM: From bench to bedside and beyond

Glioblastoma multiforme (GBM) is one of the most common and malignant form of adult brain tumor with a high mortality rate and dismal prognosis. The present standard treatment comprising surgical resection followed by radiation and chemotherapy using temozolomide can broaden patient's survival to some extent. However, the advantages are not palliative due to the development of resistance to the drug and tumor recurrence following the multimodal treatment approaches due to both intra- and intertumoral heterogeneity of GBM. One of the major contributors to temozolomide resistance is O⁶ -methylguanine-DNA methyltransferase. Furthermore, deficiency of mismatch repair, base excision repair, and cytoprotective autophagy adds to temozolomide obstruction. Rising proof additionally showed that a small population of cells displaying certain stem cell markers, known as glioma stem cells, adds on to the resistance and tumor progression. Collectively, these findings necessitate the discovery of novel therapeutic avenues for treating glioblastoma. As of late, after understanding the pathophysiology and biology of GBM, some novel therapeutic discoveries, such as drug repurposing, targeted molecules, immunotherapies, antimitotic therapies, and microRNAs, have been developed as new potential treatments for glioblastoma. To help illustrate, "what are the mechanisms of resistance to temozolomide" and "what kind of alternative therapeutics can be suggested" with this fatal disease, a detailed history of these has been discussed in this review article, all with a hope to develop an effective treatment strategy for GBM.

miRNA signature in glioblastoma: Potential biomarkers and therapeutic targets

MicroRNAs (miRNAs) are transcripts with sizes of about 22 nucleotides, which are produced through a multistep process in the nucleus and cytoplasm. These transcripts modulate the expression of their target genes through binding with certain target regions, particularly 3' suntranslated regions. They are involved in the pathogenesis of several kinds of cancers, such as glioblastoma. Several miRNAs, including miR-10b, miR-21, miR-17-92-cluster, and miR-93, have been up-regulated in glioblastoma cell lines and clinical samples. On the other hand, expression of miR-7, miR-29b, miR-32, miR-34, miR-181 family members, and a number of other miRNAs have been decreased in this type of cancer. In the current review, we explain the role of miRNAs in the pathogenesis of glioblastoma through providing a summary of studies that reported dysregulation of these epigenetic effectors in this kind of brain cancer.

miR-124 Intensified Oxaliplatin-Based Chemotherapy by Targeting CAPN2 in Colorectal Cancer

Our previous study demonstrated that miR-124 was downregulated in colorectal cancer (CRC) compared with normal mucosa, and the downregulated expression of miR-124 was an independent prognostic factor in CRC patients. However, the function of miR-124 in CRC patients treated with chemotherapy is currently unclear. The aim of this study was to determine the miR-124 expression and its regulative role in oxaliplatin (L-OHP)-based chemotherapy of CRC patients. We observed that low miR-124 expression was correlated with worse overall survival (OS) in the 220 patients who received postoperative chemotherapy of 5-fluorouracil [5-FU]+leucovorin+L-OHP (FOLFOX) or capecitabine+L-OHP (XELOX). miR-124 overexpression promoted L-OHP-induced, but not 5-FU-induced, cytotoxicity and apoptosis in HT29 and SW480 cells. CAPN2 was a direct target of miR-124, and its protein expression was reduced by forced expression of miR-124. miR-124 inhibited tumorigenesis and promoted OS of mice bearing xenograft tumors, especially upon L-OHP treatment. miR-124 also promoted L-OHP-induced apoptosis and restrained CAPN2 protein expression in xenograft tumors. Our results suggest that miR-124 could be considered as both a predictor of L-OHP-based chemotherapy for personalized treatment and a therapeutic target for CRC.

Emerging Roles and Potential Applications of Non-Coding RNAs in Glioblastoma

Non-coding RNAs (ncRNAs) comprise a diversity of RNA species, which do not have the potential to encode proteins. Non-coding RNAs include two classes of RNAs, namely: short regulatory ncRNAs and long non-coding RNAs (lncRNAs). The short regulatory RNAs, containing up to 200 nucleotides, include small RNAs, such as microRNAs (miRNA), short interfering RNAs (siRNAs), piwi-interacting RNAs (piRNAs), and small nucleolar RNAs (snoRNAs). The lncRNAs include long antisense RNAs and long intergenic RNAs (lincRNAs). Non-coding RNAs have been implicated as master regulators of several biological processes, their expression being strictly regulated under physiological conditions. In recent years, particularly in the last decade, substantial effort has been made to investigate the function of ncRNAs in several human diseases, including cancer. Glioblastoma is the most common and aggressive type of brain cancer in adults, with deregulated expression of small and long ncRNAs having been implicated in onset, progression, invasiveness, and recurrence of this tumor. The aim of this review is to guide the reader through important aspects of miRNA and lncRNA biology, focusing on the molecular mechanism associated with the progression of this highly malignant cancer type.

The therapeutic potential of Aurora kinases targeting in glioblastoma: from preclinical research to translational oncology

Glioblastoma is the most common aggressive primary brain tumor. Standard care includes maximal safe surgical resection, radiation, and chemotherapy with temozolomide. However, the impact of this therapeutic approach on patient survival is disappointing and poor outcomes are frequently observed. Therefore, new therapeutic targets are needed to treat this potentially deadly tumor. Aurora kinases are one of today's most sought-after classes of therapeutic targets to glioblastoma therapy. They are a family of proteins composed of three members: Aurora-A, Aurora-B, and Aurora-C that play different roles in the cell division through regulation of chromosome segregation. Deregulation of these genes has been reported in glioblastoma and a progressive number of studies have shown that inhibition of these proteins could be a promising strategy for the treatment of this tumor. This review discusses the preclinical and early clinical findings on the potential use of the Aurora kinases as new targets for the treatment of glioblastoma. KEY MESSAGES: GBM is a very aggressive tumor with limited therapeutic options. Aurora kinases are a family of serine/threonine kinases implicated in GBM pathology. Aurora kinases are critical for glioblastoma cell growth, apoptosis, and chemoresistance. Inhibition of Aurora kinases has a synergistic or sensitizing effect with chemotherapy drugs, radiotherapy, or with other targeted molecules in GBM. Several Aurora kinase inhibitors are currently in clinical trials.

Natural killer T cell cytotoxic activity in cervical cancer is facilitated by the LINC00240/microRNA-124-3p/STAT3/MICA axis

Long noncoding RNAs play significant roles in diverse cancers. In this study, we found that LINC00240 expression was markedly increased in cervical cancer. Functional in vitro assays in cervical cancer cells showed that LINC00240 enhanced the growth, migration, and invasion of cervical cancer cells. The target of LINC00240 was confirmed as microRNA(miR)-124-3p. Inhibition of miR-124-3p significantly enhanced cervical cancer progression via targeting of STAT3, which is greatly activated in tumor-infiltrating immune cells. LINC00240 expression was able to induce STAT3 expression via sponging of miR-124-3p, and showed a positive association with STAT3 expression in cervical cancer tissues. MHC class I-related chain (MIC)-A plays a key role in activating natural killer T (NKT) cells and serves as a downstream target of STAT3. Here, MICA was inhibited by up-regulation of LINC00240, and could be rescued by STAT3 knockdown. In addition, LINC00240 overexpression suppressed the cytotoxic activity of NKT cells by affecting the STAT3/MICA axis. Subsequently, we found that LINC00240 expression promoted cervical cancer progression via induction of miR-124-3p/STAT3/MICA-mediated NKT cell tolerance. Considering these findings, we conclude that LINC00240 might be a novel target for cervical cancer.

p62 acts as an oncogene and is targeted by miR-124-3p in glioma

Background

Glioma is the most common central nervous system (CNS) tumour. p62, an important autophagy adaptor, plays a crucial role in cancer. However, the role of p62 in the progression of glioma is poorly characterized.

Methods

We examined the expression of p62 in glioma tissues and cell lines. Then we investigated the function of p62 in vitro, and clarified the mechanism underlying the regulation of p62 expression.

Results

We revealed that p62 was upregulated at both the mRNA and protein levels in human glioma tissues irrelevant to isocitrate dehydrogenase (IDH) status. Then, we found that overexpression of p62 promoted glioma progression by promoting proliferation, migration, glycolysis, temozolomide (TMZ) resistance and nuclear factor κB (NF-κB) signalling pathway, and repressing autophagic flux and reactive oxygen species (ROS) in vitro. In accordance with p62 overexpression, knockdown of p62 exerted anti-tumour effects in glioma cells. Subsequently, we demonstrated that miR-124-3p directly targeted the 3′-UTR of p62 mRNA, leading to the downregulation of p62. Finally, we found that p62 function could be partially reversed by miR-124-3p overexpression.

Conclusions

Our results demonstrate that p62 can be targeted by miR-124-3p and acts as an oncogene in glioma, suggesting the potential value of p62 as a novel therapeutic target for glioma.

MicroRNA-124-3p suppresses cell migration and invasion by targeting ITGA3 signaling in bladder cancer

BACKGROUND

A growing body of studies have demonstrated the aberrant expression of microRNAs (miRNAs) contributes to human tumor metastasis. MicroRNA-124-3p (miR-124-3p), which is down-regulated in various cancers, has been found to be involved in several signaling pathways relevant to tumor cell migration and invasion. However, the roles of miR-124-3p in human bladder cancer remain unclear. This study aims to investigate the functional significance of miR-124-3p and to understand how it targets the integrin receptor, and thus affects the progression of human bladder cancer.

METHODS

Clinical specimens from 36 patients and three human bladder cancer cell lines were analyzed for miR-124-3p and integrin α3 (ITGA3) . To investigate the effects of miR-124-3p and ITGA3 on proliferation of bladder cancer cells, the MTT assay, colon-formation assay and flow cytometry were performed. In addition, wound healing assay and transwell assay were carried out to examine the migration and invasion of the bladder cancer cells transfected with miR-124-3p mimics or si-ITGA3. The luciferase reporter assay, quantitative real-time polymerase chain reaction (qRT-PCR) and western blot were applied to validate the miR-124-3p directly binding with ITGA3. Finally, western blot was used to examine the expression level of the proteins involved in FAK/PI3K/AKT and FAK/Src signal pathway as well as epithelial-mesenchymal transition (EMT) process.

RESULTS

The down-regulation of miR-124-3p and up-regulation of ITGA3 were observed in clinical specimens and bladder cancer cell lines. Overexpression of miR-124-3p or silencing ITGA3 inhibited tumor cell migration and invasion. Luciferase assay confirmed miR-124-3p directly targets ITGA3, and western blot suggested that miR-124-3p plays a crucial role in the EMT and metastasis of human bladder cancer through FAK/PI3K/AKT and FAK/Src signaling mechanism. Also, by targeting ITGA3, miR-124-3p can modulate the expression of N- and E-cadherin, and thus inhibit the EMT.

CONCLUSIONS

By targeting ITGA3 and downstream FAK/PI3K/AKT and FAK/Src signaling pathways, miR-124-3p suppresses cell migration and invasion in bladder cancer. Our study reasonably speculates that miR-124-3p can be potentially developed as a therapeutic target and prognostic biomarker for bladder cancer.

Inhibition of microRNA-124a attenuates non-alcoholic fatty liver disease through upregulation of adipose triglyceride lipase and the effect of liraglutide intervention

AIM

Glucagon-like peptide-1 receptor agonists (GLP-1Ras) have been reported to prevent non-alcoholic fatty liver disease (NAFLD), but the potential mechanisms are still debated. MicroRNAs (miRNAs) play a prominent role in the field of metabolic disorders, including NAFLD. Our study was designed to further evaluate the effect of GLP-1Ra liraglutide on NAFLD in terms of miRNAs.

METHODS

MicroRNA expression was evaluated by clustering analysis of microRNA arrays in high fat diet-fed mice. The luciferase reporter assay was carried out to validate the cross-talk between adipose triglyceride lipase (ATGL) and miR-124a. MicroRNA-124a mimics and inhibitor plasmids were transfected to study the role of miR-124a in palmitate-treated normal human liver cell line (HL-7702). Liraglutide treatment was used to observe the effect of GLP-1Ra on the miR-124a/ATGL pathway.

RESULTS

Expression of ATGL decreased and miR-124a expression increased in hepatosteatosis in vivo and in vitro. Mechanistically, miR-124a interacted with the 3'-untranslated region of ATGL mRNA and induced its degradation. MicroRNA-124a overexpression antagonized the effect of liraglutide on NAFLD by inhibiting ATGL expression, whereas miR-124a knockdown led to elevated ATGL and sirtuin 1 (Sirt1) expression, and subsequently decreased lipid accumulation and inflammation in cells.

CONCLUSIONS

MicroRNA-124a overexpression contributes to the progression of NAFLD through reduction of ATGL expression, whereas miR-124a knockdown can reverse this trend, suggesting that miR-124a and its downstream target ATGL can be novel therapeutic targets of NAFLD. We reveal a novel mechanism by which liraglutide attenuates NAFLD by the miR-124a/ATGL/Sirt1 pathway.

Hypermethylation-mediated inactivation of miR-124 predicts poor prognosis and promotes tumor growth at least partially through targeting EZH2/H3K27me3 in ESCC

Accumulating evidences indicated that some microRNAs (miRNAs) play a critical role during the carcinogenesis. In the present study, we found that miR-124 is down-regulated in esophageal squamous cell carcinoma (ESCC) tissues. Three miR-124 encoding genes, including mir-124-1, mir-124-2, and mir-124-3, harboring CpG islands undergo methylation-mediated miR-124 inactivation in ESCC tissues. The methylation status of all these three genes was negatively associated with the expression of miR-124. The low expression of miR-124 and the hypermethylation of mir-124-1 and mir-124-3 were associated with the clinico-pathological parameters indicating the poor prognosis. In addition, promoter methylation of all three genes plus low expression of miR-124 was the independent poor prognostic marker for ESCC patients. In conclusion, miR-124 may function as a tumor suppressive miRNA, and hypermethylation-mediated inactivation of miR-124 may be useful for a poor prognostic marker for ESCC patients.

Resveratrol (3, 5, 4'-Trihydroxy-trans-Stilbene) Attenuates a Mouse Model of Multiple Sclerosis by Altering the miR-124/Sphingosine Kinase 1 Axis in Encephalitogenic T Cells in the Brain

Resveratrol (3,5,4'-trihydroxy-trans-stilbene) (RES) is a naturally-derived phytoestrogen found in the skins of red grapes and berries and has potential as a novel and effective therapeutic agent. In the current study, we investigated the role of microRNA (miRNA) in RES-mediated attenuation of experimental autoimmune encephalomyelitis (EAE), a murine model of multiple sclerosis. Administration of RES effectively decreased disease severity, including inflammation and central nervous system immune cell infiltration. miRNA microarray analysis revealed an altered miRNA profile in encephalitogenic CD4+ T cells from EAE mice exposed to RES treatment. Additionally, bioinformatics and in silico pathway analysis suggested the involvement of RES-induced miRNA in pathways and processes that regulated cellular proliferation. Additional studies confirmed that RES affected cell cycle progression and apoptosis in activated T cells, specifically in the brain. RES treatment significantly upregulated miR-124 during EAE, while suppressing associated target gene, sphingosine kinase 1 (SK1), and this too was specific to mononuclear cells in the brains of treated mice, as peripheral immune cells remained unaltered upon RES treatment. Collectively, these studies demonstrate that RES treatment leads to amelioration of EAE development through mechanism(s) potentially involving suppression of neuroinflammation via alteration of the miR-124/SK1 axis, thereby halting cell-cycle progression and promoting apoptosis in activated encephalitogenic T cells. Graphical Abstract Resveratrol alters the miR-124/sphingosine kinase 1 (SK1) axis in encephalitogenic T cells, promotes cell-cycle arrest and apoptosis, and decreases neuroinflammation in experiemental autoimmune encephalomyelitis (EAE).

The functional synergism of microRNA clustering provides therapeutically relevant epigenetic interference in glioblastoma

MicroRNA deregulation is a consistent feature of glioblastoma, yet the biological effect of each single gene is generally modest, and therapeutically negligible. Here we describe a module of microRNAs, constituted by miR-124, miR-128 and miR-137, which are co-expressed during neuronal differentiation and simultaneously lost in gliomagenesis. Each one of these miRs targets several transcriptional regulators, including the oncogenic chromatin repressors EZH2, BMI1 and LSD1, which are functionally interdependent and involved in glioblastoma recurrence after therapeutic chemoradiation. Synchronizing the expression of these three microRNAs in a gene therapy approach displays significant anticancer synergism, abrogates this epigenetic-mediated, multi-protein tumor survival mechanism and results in a 5-fold increase in survival when combined with chemotherapy in murine glioblastoma models. These transgenic microRNA clusters display intercellular propagation in vivo, via extracellular vesicles, extending their biological effect throughout the whole tumor. Our results support the rationale and feasibility of combinatorial microRNA strategies for anticancer therapies.

The delivery of single therapeutic microRNAs in brain cancers is challenging. Here, the authors engineer three neuronal microRNAs (miR-124, 128 and 137) into a cluster that, targeting oncogenic chromatin repressors, increases survival of GBM-bearing mice when combined with chemotherapy.

Phase I trial of alisertib with concurrent fractionated stereotactic re-irradiation for recurrent high grade gliomas

BACKGROUND AND PURPOSE

We conducted a phase I trial of alisertib, an oral aurora kinase inhibitor, with fractionated stereotactic re-irradiation therapy (FSRT) for patients with recurrent high grade glioma (HGG).

MATERIALS AND METHODS

Adult patients with recurrent HGG were enrolled from Feb 2015 to Feb 2017. Patients were treated with concurrent FSRT and alisertib followed by maintenance alisertib. Concurrent alisertib dose was escalated from 20 mg to 50 mg twice daily (BID).

RESULTS

17 patients were enrolled. Median follow-up was 11 months. Median FSRT dose was 35 Gy. There were 6, 6, 3, and 2 patients enrolled in 20 mg, 30 mg, 40 mg, and 50 mg cohort, respectively. Only one DLT was observed. One patient in the 20 mg cohort had severe headache (Grade 3) resolved with steroids. There was no non-hematological grade 3 or higher toxicity. There were two Grade 4 late toxicities (one with grade 4 neutropenia and leukopenia, one with pulmonary embolism). One patient developed radiation necrosis (Grade 3). Sixteen patients finished concurrent treatment and received maintenance therapy (median cycles was 3, range 1-9). OS for all cohorts at 6 months was 88.2% with median survival time of 11.1 months. PFS at 6 months was 35.3% with median time to progression of 4.9 months. The trial stopped early due to closure of alisertib program with only 2 of 3 planned patients enrolled in the 50 mg cohort.

CONCLUSION

Re-irradiation with FSRT combined with alisertib is safe and well tolerated for HGG with doses up to 40 mg BID. Although no DLT observed in the 50 mg cohort, this cohort was not fully enrolled and MTD was not reached. Clinical outcomes appear comparable to historical results. (NCT02186509).

Identification of Core Biomarkers Associated with Outcome in Glioma: Evidence from Bioinformatics Analysis

Glioma is the most common neoplasm of the central nervous system (CNS); the progression and outcomes of which are affected by a complicated network of genes and pathways. We chose a gene expression profile of GSE66354 from GEO database to search core biomarkers during the occurrence and development of glioma. A total of 149 samples, involving 136 glioma and 13 normal brain tissues, were enrolled in this article. 1980 differentially expressed genes (DEGs) including 697 upregulated genes and 1283 downregulated genes between glioma patients and healthy individuals were selected using GeoDiver and GEO2R tool. Then, gene ontology (GO) analysis as well as Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were carried out using the Database for Annotation, Visualization and Integrated Discovery (DAVID). Moreover, Cytoscape with Search Tool for the Retrieval of Interacting Genes (STRING) and Molecular Complex Detection (MCODE) plug-in was employed to imagine protein-protein interaction (PPI) of these DEGs. The upregulated genes were enriched in cell cycle, ECM-receptor interaction, and p53 signaling pathway, while the downregulated genes were enriched in retrograde endocannabinoid signaling, glutamatergic synapse, morphine addiction, GABAergic synapse, and calcium signaling pathway. Subsequently, 4 typical modules were discovered by the PPI network utilizing MCODE software. Besides, 15 hub genes were chosen according to the degree of connectivity, including TP53, CDK1, CCNB1, and CCNB2, the Kaplan-Meier analysis of which was further identified. In conclusion, this bioinformatics analysis indicated that DEGs and core genes, such as TP53, might influence the development of glioma, especially in tumor proliferation, which were expected to be promising biomarkers for diagnosis and treatment of glioma.

An Aurora kinase inhibitor, AMG900, inhibits glioblastoma cell proliferation by disrupting mitotic progression

The Aurora kinase family of serine/threonine protein kinases comprises Aurora A, B, and C and plays an important role in mitotic progression. Several inhibitors of Aurora kinase have been developed as anti‐cancer therapeutics. Here, we examined the effects of a pan‐Aurora kinase inhibitor, AMG900, against glioblastoma cells. AMG900 inhibited proliferation of A172, U‐87MG, and U‐118MG glioblastoma cells by upregulating p53 and p21 and subsequently inducing cell cycle arrest and senescence. Abnormal cell cycle progression was triggered by dysregulated mitosis. Mitosis was prolonged due to a defect in mitotic spindle assembly. Despite the presence of an unattached kinetochore, BubR1, a component of the spindle assembly checkpoint, was not recruited. In addition, Aurora B was not recruited to central spindle at anaphase. Abnormal mitotic progression resulted in accumulation of multinuclei and micronuclei, a type of chromosome missegregation, and ultimately inhibited cell survival. Therefore, the data suggest that AMG900‐mediated inhibition of Aurora kinase is a potential anti‐cancer therapy for glioblastoma.

Amentoflavone induces apoptosis and suppresses glycolysis in glioma cells by targeting miR-124-3p

Malignant glioma is the most common type of brain tumor with poor clinical outcome and survival. Therefore, it is imperative to develop novel therapeutic agents for managing glioma. The aim of this study was to investigate the role of amentoflavone (AF), an active flavonoid component in Selaginella tamariscina Spring, in glioma cells and the underlying mechanism of its action. Our results showed that miR-124-3p expression was significantly down-regulated in glioma tissues relative to normal brain tissues. AF decreased cell viability and triggered apoptosis in both glioma cell lines in a dose-dependent manner. AF induced apoptosis and inhibited glycolysis in the glioma cells by upregulating miR-124-3p. Furthermore, AF upregulated miR-124-3p by repressing DNMT1 through Sp1, which in turn was caused by the activation of ROS/AMPK signaling pathway by AF. In conclusion, AF could induce apoptosis and inhibited glycolysis in glioma cells via miR-124-3p. Our findings provide preliminary experimental data that support further investigation on the therapeutic efficacy of AF in glioma.

MiR-129 regulates growth and invasion by targeting MAL2 in papillary thyroid carcinoma

MAL2, a member of the MAL proteolipid family, is essential for raft-mediated transport. In this study, we investigated the roles and underlying mechanism of MAL2 in the development of papillary thyroid carcinoma (PTC). Up-regulation of MAL2 was found in human PTC tissues and significantly correlated with poor overall survival (OS). Knockdown of MAL2 dramatically suppressed PTC cell proliferation and invasion in vitro and inhibited tumor growth in vivo. We further found that miR-129 suppressed the expression of MLA through directly binding to the 3' untranslated region (3' UTR). While forced miR-129 expression suppressed growth and invasion of PTC cells, re-expression of MAL2 rescued these effects. Taken together, our data indicated that MAL2 acted as an oncogene and was negatively regulated by miR-129, supporting the potential therapeutic strategy against PTC by targeting miR-129-MAL2 axis.

Molecular Determinants of Malignant Brain Cancers: From Intracellular Alterations to Invasion Mediated by Extracellular Vesicles

Malignant glioma cells invade the surrounding brain parenchyma, by migrating along the blood vessels, thus promoting cancer growth. The biological bases of these activities are grounded in profound alterations of the metabolism and the structural organization of the cells, which consequently acquire the ability to modify the surrounding microenvironment, by altering the extracellular matrix and affecting the properties of the other cells present in the brain, such as normal glial-, endothelial- and immune-cells. Most of the effects on the surrounding environment are probably exerted through the release of a variety of extracellular vesicles (EVs), which contain many different classes of molecules, from genetic material to defined species of lipids and enzymes. EV-associated molecules can be either released into the extracellular matrix (ECM) and/or transferred to neighboring cells: as a consequence, both deep modifications of the recipient cell phenotype and digestion of ECM components are obtained, thus causing cancer propagation, as well as a general brain dysfunction. In this review, we first analyze the main intracellular and extracellular transformations required for glioma cell invasion into the brain parenchyma; then we discuss how these events may be attributed, at least in part, to EVs that, like the pawns of a dramatic chess game with cancer, open the way to the tumor cells themselves.