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Malignant gliomas are known to be one of the most difficult diseases to diagnose and treat because of the infiltrative growth pattern, rapid progression, and poor prognosis. Many antitumor drugs are not ideal for the treatment of gliomas due to the blood-brain barrier. Temozolomide (TMZ) is a DNA alkylating agent that can cross the blood-brain barrier. As the only first-line chemotherapeutic drug for malignant gliomas at present, TMZ is widely utilized to provide a survival benefit; however, some patients are inherently insensitive to TMZ. In addition, patients could develop acquired resistance during TMZ treatment, which limits antitumor efficacy. To clarify the mechanism underlying TMZ resistance, numerous studies have provided multilevel solutions, such as improving the effective concentration of TMZ in tumors and developing novel small molecule drugs. This review discusses the in-depth mechanisms underlying TMZ drug resistance, thus aiming to provide possibilities for the establishment of personalized therapeutic strategies against malignant gliomas and the accelerated development and transformation of new targeted drugs.

Background Temozolomide (TMZ) resistance has become an important obstacle affecting its therapeutic benefits. O6-methylguanine DNA methyltransferase (MGMT) is primarily responsible for the TMZ resistance in Glioblastoma multiforme (GBM) patients. In addition, active DNA damage repair pathways can also lead to TMZ resistance. Here, we reported a novel small-molecule inhibitor EPIC-0412 that improved the therapeutic efficacy of TMZ by inhibiting the DNA damage repair pathway and MGMT in GBM via epigenetic pathways. Methods The small-molecule compound EPIC-0412 was obtained through high-throughput screening. RNA immunoprecipitation (RIP), chromatin isolation by RNA purification (ChIRP), and chromatin immunoprecipitation (ChIP) assays were used to verify the effect of EPIC-0412. Co-immunoprecipitation (Co-IP) was used to elucidate the interactions of transcription factors at the MGMT promoter region. Animal experiments using a mouse model were performed to verify the efficacy of EPIC-0412 in sensitizing GBM cells to TMZ. Results EPIC-0412 physically interrupts the binding of HOTAIR and EZH2, leading to the upregulation of CDKN1A and BBC3, causing cell cycle arrest and apoptosis in GBM cells. EPIC-0412 inhibits DNA damage response in GBM cells through the p21-E2F1 DNA damage repair axis. EPIC-0412 epigenetically silences MGMT through its interaction with the ATF3-p-p65-HADC1 axis at the MGMT promoter region. The application of EPIC-0412 restored the TMZ sensitivity in GBM in vivo experiments. Conclusion This study discovered a small-molecule inhibitor EPIC-0412, which enhanced the chemotherapeutic effect of TMZ by acting on the p21-E2F1 DNA damage repair axis and ATF3-p-p65-MGMT axis, providing evidence for combining epigenetic drugs to increase the sensitization toward TMZ in GBM patients.

Background Targeting glioblastoma (GBM) energy metabolism through multiple metabolic pathways has emerged as an effective therapeutic approach. Dual inhibition of phospholipid and mitochondrial metabolism with cytoplasmic phospholipase A2 (cPLA2) knockdown and metformin treatment could be a potential strategy. However, the strategic prerequisite is to explore a carrier capable of co-delivering the therapeutic combination to cross the blood-brain barrier (BBB) and preferentially accumulate at the GBM site. Methods Blood exosomes (Exos) were selected as the combination delivery carriers. The cellular uptake of Exos and the therapeutic effects of the combination strategy were evaluated in primary GBM cells. In vivo GBM-targeted delivery efficiency and anti-GBM efficacy were tested in a patient-derived xenograft (PDX) model. Results Here, we showed that the Exos-mediated cPLA2 siRNA/metformin combined strategy could regulate GBM energy metabolism for personalized treatment. Genomic analysis and experiments showed that polymerase 1 and transcript release factor (PTRF, a biomarker of GBM) positively regulated the uptake of Exos by GBM cells, confirming the feasibility of the delivery strategy. Further, Exos could co-load cPLA2 siRNA (sicPLA2) and metformin and co-deliver them across the BBB and into GBM tissue. The mitochondrial energy metabolism of GBM was impaired with this combination treatment (Exos-Met/sicPLA2). In the PDX GBM model, systemic administration of Exos-Met/sicPLA2 reduced tumor growth and prolonged survival. Conclusions Our findings demonstrated that Exos-based combined delivery of sicPLA2 and metformin selectively targeted the GBM energy metabolism to achieve antitumor effects, showing its potential as a personalized therapy for GBM patients.

To follow the revision of the fourth edition of WHO classification and the recent progress on the management of diffuse gliomas, the joint guideline committee of Chinese Glioma Cooperative Group (CGCG), Society for Neuro-Oncology of China (SNO-China) and Chinese Brain Cancer Association (CBCA) updated the clinical practice guideline. It provides recommendations for diagnostic and management decisions, and for limiting unnecessary treatments and cost. The recommendations focus on molecular and pathological diagnostics, and the main treatment modalities of surgery, radiotherapy, and chemotherapy. In this guideline, we also integrated the results of some clinical trials of immune therapies and target therapies, which we think are ongoing future directions. The guideline should serve as an application for all professionals involved in the management of patients with adult diffuse glioma and also a source of knowledge for insurance companies and other institutions involved in the cost regulation of cancer care in China and other countries.

Background Metabolism remodeling is a hallmark of glioblastoma (GBM) that regulates tumor proliferation and the immune microenvironment. Previous studies have reported that increased polymerase 1 and transcript release factor (PTRF) levels are associated with a worse prognosis in glioma patients. However, the biological role and the molecular mechanism of PTRF in GBM metabolism remain unclear. Methods The relationship between PTRF and lipid metabolism in GBM was detected by nontargeted metabolomics profiling and subsequent lipidomics analysis. Western blotting, quantitative real-time PCR, and immunoprecipitation were conducted to explore the molecular mechanism of PTRF in lipid metabolism. A sequence of in vitro and in vivo experiments (both xenograft tumor and intracranial tumor mouse models) were used to detect the tumor-specific impacts of PTRF. Results Here, we show that PTRF triggers a cytoplasmic phospholipase A2 (cPLA2)–mediated phospholipid remodeling pathway that promotes GBM tumor proliferation and suppresses tumor immune responses. Research in primary cell lines from GBM patients revealed that cells overexpressing PTRF show increased cPLA2 activity—resulting from increased protein stability—and exhibit remodeled phospholipid composition. Subsequent experiments revealed that PTRF overexpression alters the endocytosis capacity and energy metabolism of GBM cells. Finally, in GBM xenograft and intracranial tumor mouse models, we showed that inhibiting cPLA2 activity blocks tumor proliferation and prevents PTRF-induced reduction in CD8+ tumor-infiltrating lymphocytes. Conclusions The PTRF-cPLA2 lipid remodeling pathway promotes tumor proliferation and suppresses immune responses in GBM. In addition, our findings highlight multiple new therapeutic targets for GBM.

Glioblastoma (GBM) is the most common and lethal type of primary malignant central nervous system (CNS) tumor with an extremely poor prognosis, and the mesenchymal subtype of GBM has the worst prognosis. Here, we found that lncRNA PRADX was overexpressed in the mesenchymal GBM and was transcriptionally regulated by RUNX1-CBFβ complex, overexpressed PRADX suppressed BLCAP expression via interacting with EZH2 and catalyzing trimethylation of lysine 27 on histone H3 (H3K27me3). Moreover, we showed that BLCAP interacted with STAT3 and reduced STAT3 phosphorylation, overexpressed PRADX activated STAT3 phosphorylation, and promoted ACSL1 expression via suppressing BLCAP expression, accelerating tumor metabolism. Finally, we determined that combined of ACSL1 and CPT1 inhibitors could reverse the accelerated cellular metabolism and tumor growth induced by PRADX overexpression in vivo and in vitro. Collectively, PRADX/PRC2 complex activated the STAT3 pathway and energy metabolism in relation to mesenchymal GBM progression. Furthermore, our findings provided a novel therapeutic strategy targeting the energy metabolism activity of GBM.

Objective: The introduction of therapeutic antibodies (tAbs) into clinical practice has revolutionized tumor treatment strategies, but their tumor therapy efficiency is still far below expectations because of the rapid degradation and limited tumor accumulation of tAbs. Methods: We developed a nanocapsule-based delivery system to induce the self-augmentation of the enhanced permeability and retention (EPR) effect. This system constantly penetrated across the blood-tumor barrier into the tumor while avoiding the attack of tAbs by the immune system. The biodistribution and therapeutic effect were tested with single dose administration of nanocapsule-tAbs in vivo. Results: The accumulation of Nano(cetuximab) within subcutaneous PC9 tumors was gradually enhanced over 6 days after single dose administration, which was contrary to the biodistribution of native cetuximab. Nano(cetuximab) accumulated in tumor tissues via the EPR effect and released cetuximab. The released cetuximab acted on vascular endothelial cells to destroy the blood-tumor barrier and induce self-augmentation of the EPR effect, which in turn contributed to further tumor accumulation of long-circulating Nano(cetuximab). Compared with single dose administration of native cetuximab, Nano(cetuximab) showed an effective tumor suppressive effect for 3 weeks. Conclusions: The nanocapsule-based delivery system efficiently delivered tAbs to tumor tissues and released them to boost the EPR effect, which facilitated further tumor accumulation of the tAbs. This novel self-augmentation of the EPR effect facilitated by the biological characteristics of tAbs and nanotechnology contributed to the improvement of the therapeutic effect of tAbs, and stimulated new ideas for antibody-based tumor therapy.

BackgroundThe main immune cells in GBM are tumor-associated macrophages (TAMs). Thus far, the studies investigating the activation status of TAM in GBM are mainly limited to bulk RNA analyses of individual tumor biopsies. The activation states and transcriptional signatures of TAMs in GBM remain poorly characterized.MethodsWe comprehensively analyzed single-cell RNA-sequencing data, covering a total of 16,201 cells, to clarify the relative proportions of the immune cells infiltrating GBMs. The origin and TAM states in GBM were characterized using the expression profiles of differential marker genes. The vital transcription factors were examined by SCENIC analysis. By comparing the variable gene expression patterns in different clusters and cell types, we identified components and characteristics of TAMs unique to each GBM subtype. Meanwhile, we interrogated the correlation between SPI1 expression and macrophage infiltration in the TCGA-GBM dataset.ResultsThe expression patterns of TMEM119 and MHC-II can be utilized to distinguish the origin and activation states of TAMs. In TCGA-Mixed tumors, almost all TAMs were bone marrow-derived macrophages. The TAMs in TCGA-proneural tumors were characterized by primed microglia. A different composition was observed in TCGA-classical tumors, which were infiltrated by repressed microglia. Our results further identified SPI1 as a crucial regulon and potential immunotherapeutic target important for TAM maturation and polarization in GBM.ConclusionsWe describe the immune landscape of human GBM at a single-cell level and define a novel categorization scheme for TAMs in GBM. The immunotherapy against SPI1 would reprogram the immune environment of GBM and enhance the treatment effect of conventional chemotherapy drugs.

The dynamic changes of RNA N6-methyl-adenosine (m6A) during cancer progression contribute to quick adaption to microenvironmental changes. Here, we profiled the cancer cell m6A dynamics in the hypoxic tumor niche and its pathological consequences in glioblastoma multiforme (GBM). The m6A demethylase ALKBH5 was induced in GBM models under hypoxic conditions and was associated with a hypoxic gene signature in GBM patient samples. Depletion or inactivation of ALKBH5 in GBM cells significantly suppressed hypoxia-induced tumor-associated macrophage (TAM) recruitment and immunosuppression in allograft tumors. Expression and secretion of CXCL8/IL8 were significantly suppressed in ALKBH5-deficient tumors. However, ALKBH5 did not regulate CXCL8 m6A directly. Instead, hypoxia-induced ALKBH5 erased m6A deposition from the lncRNA NEAT1, stabilizing the transcript and facilitating NEAT1-mediated paraspeckle assembly, which led to relocation of the transcriptional repressor SFPQ from the CXCL8 promoter to paraspeckles and, ultimately, upregulation of CXCL8/IL8 expression. Accordingly, ectopic expression of CXCL8 in ALKBH5-deficient GBM cells partially restored TAM recruitment and tumor progression. Together, this study links hypoxia-induced epitranscriptomic changes to the emergence of an immunosuppressive microenvironment facilitating tumor evasion. Significance: Hypoxia induces tumor immune microenvironment remodeling through an ALKBH5-mediated epigenetic and epitranscriptomic mechanism, providing potential immunotherapeutic strategies for treating glioblastoma.

Objective: ATRX is a multifunctional protein that is tightly regulated by and implicated in transcriptional regulation andchromatin remodeling. Numerous studies have shown that genetic alterations in ATRX play a significant role in gliomas. Thisstudy aims to further determine the relationship between ATRX and glioma prognosis and identify possible mechanisms forexploring the biological significance of ATRX using large data sets. Methods: We used The Cancer Genome Atlas (TCGA) database and 130 immunohistochemical results to confirm the differencein ATRX mutations in high- and low-grade gliomas. An online analysis of the TCGA glioma datasets using the cBioPortal platformwas performed to study the relationship between ATRX mutations and IDH1, TP53, CDKN2A and CDKN2B mutations in thecorresponding TCGA glioma dataset. In combination with clinical pathology data, the biological significance of the relationshipswere analyzed. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses and annotationsof all adjacent genes in the network were performed the Database for Annotation, Visualization and Integrated Discovery(DAVID) and R language. A protein-protein interaction (PPI) network was constructed, and the interactions of all adjacent nodeswere analyzed by the String database and using Cytoscape software. Results: In the selected TCGA glioma datasets, a total of 2,228 patients were queried, 21% of whom had ATRX alterations, whichco-occurred frequently with TP53 and IDH1 mutations. ATRX alterations are associated with multiple critical molecular events,which results in a significantly improved overall survival (OS) rate. In low-grade gliomas, ATRX mutations are significantlyassociated with multiple important molecular events, such as ZNF274 and FDXR at mRNA and protein levels. A functional clusteranalysis revealed that these genes played a role in chromatin binding and P53, and a link was observed between ATRX and IDH1and TP53 in the interaction network. ATRX and TP53 are important nodes in the network and have potential links with the bloodoxygen imbalance. Conclusions: ATRX mutations have clinical implications for the molecular diagnosis of gliomas and can provide diagnostic andprognostic information for gliomas. ATRX is expected to serve as a new therapeutic target. Cite this article as: Xie Y, Tan Y, Yang C, Zhang X, Xu C, Qiao X, et al.Omics-based integrated analysis identified ATRX as a biomarker associatedwith glioma diagnosis and prognosis. Cancer Biol Med. 2019; 16: 784-96. doi:10.20892/j.issn.2095-3941.2019.0143

Dysregulation of the cell cycle is a key indicator of tumors, including lung cancer. Recently, the study of cell cycle inhibitors has made great progress in relation to lung cancer. However, the question of what kinds of patients can use cell cycle inhibitors has plagued us. Therefore, seeking an accurate and convenient marker for the abnormal cell cycle in lung cancer is very important. In the present research, we showed that lncRNA HOTAIR is an optimal indicator of cell cycle dysregulation in lung cancer. In the present study, we investigated HOTAIR-specific expression in lung primary tumor samples by analyzing the TCGA public database and 67 pairs of patients' tissues collected from our department. Through the TCGA public database KEGG analysis, HOTAIR correlates with the cell cycle pathway. We identified that HOTAIR and its 2 segments, HOTAIR3' and HOTAIR5', promote the cell cycle passing through the restriction point during G1-S phase by regulating the Rb-E2F pathway and influence non-small-cell lung cancer cell proliferation, migration and invasion through epithelial-mesenchymal transition (EMT) and the β-catenin pathway in vitro and vivo. Finally, we showed that the high expression of HOTAIR was associated with resistance to gefitinib through the dysregulated cell cycle. In conclusion, HOTAIR could be an ideal indicator of cell cycle dysregulation and guide the use of cell cycle inhibitors.

Mesenchymal subtype of glioblastoma (mesGBM) is a refractory disease condition characterized by therapeutic failure and tumor recurrence, and for the past decade, no treatment option has improved the dismal prognosis of this disease. In Cancer Genome Atlas (TCGA) GBM datasets, two of the 840 transcriptomic signature genes for GBM subtyping, TGFβ1 and TGFβ receptor type II (TβRII), were exclusively upregulated in mesGBM, indicating hyperactive TGFβ signaling. In the present study, dysregulated microRNAs (miRNAs) were identified after LY2109761 (a TβRI/II inhibitor) treatment in a mesGBM-derived cell line. Importantly, several novel miRNAs that may be missing pieces of the puzzle of TGFβ signaling-mediated pathogenesis in mesGBM were identified. Novel_miR26/56/93/97/119 were validated by quantitative PCR to correlate with TGFβ signaling activity, and novel_miR56 was selected as a promising candidate for further functional verification. A proline-rich akt substrate of 40 kDa (PRAS40), which regulates autophagy initiation by targeting mTORC1, was confirmed to be a functional target of novel_miR56. Autophagy plays dichotomous roles in the determination of GBM cell fate, and in this study, TGFβ signaling-induced novel_miR56 seemed to inhibit autophagic activity in GBM and its mesenchymal subtype, resulting in the maintenance of proliferative capability. The pro-survival effect of novel_miR56 can be impeded by intentionally downregulating its expression both in vivo and in vitro. In summary, we provide novel insight into TGFβ signaling-mediated pathogenesis and targets for the development of novel therapeutic interventions for mesGBM.

Mutations in ATRX constitute the most prevalent genetic abnormalities in gliomas. The presence of ATRX mutations in glioma serves as a marker of better prognosis with longer patient survival although the underlying mechanisms are poorly understood. In the present study, we found that ATRX biological function was significantly involved in DNA replication and repair. CRISPR/Cas9-mediated genetic inactivation of ATRX induced inhibition of cell proliferation, invasion and vasculogenic mimicry. In addition, temozolomide (TMZ) treatment induced greater DNA damage and apoptotic changes in ATRX knockout glioma cells. Moreover, we confirmed that ATRX knockout resulted in a failure to trigger ATM phosphorylation and finally restrained the activation of downstream proteins of the ATM pathway. The ATM-associated DNA repair pathway was extensively compromised in ATRX knockout cells owing to decreased histone H3K9me3 availability. Public databases also showed that patients with low ATRX expression exhibited preferable overall survival and profited more from TMZ treatment. These data suggest that ATRX is involved in DNA damage repair by regulating the ATM pathway and might serve as a prognostic maker in predicting TMZ chemosensitivity.

The diagnostic, monitoring and therapeutic options for cancers currently remain limited. These limitations represent a large threat to human health. Adaptive immunity, which is dependent on diverse repertoires of B cell receptors (BCRs) and T cell receptors (TCRs), plays a critical role in the anti-tumor immune response. Modulation and surveillance of adaptive immunity has become a powerful weapon to combat cancers. Recently, the high-throughput sequencing of immune repertoire (HTS-IR) technology, which provides a robust tool for deep sequencing repertoires of BCRs or TCRs, has been applied in the development of tumor biomarkers and immunotherapeutics for cancers. This review will first provide an overview of the advancement of HTS-IR technology at the population-cell and single-cell levels. It will then provide a current summary of the applications of HTS-IR technology in the diagnosis and monitoring of minimal residual disease (MRD), focusing on immune reconstitution after the treatment of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in B/T-cell malignancies, and the precise detection of tumor-infiltrating lymphocytes (TILs) in non-B/T-cell malignancies. Finally, current advances of HTS-IR technology in cancer immunotherapeutic applications, such as therapeutic antibodies, CAR-T cell based-adoptive immunotherapies, and neoantigen-specific TCR-T cell-based adoptive immunotherapies, will be introduced.

Intratumor heterogeneity of tumor clones and an immunosuppressive microenvironment in cancer ecosystems contribute to inherent difficulties for tumor treatment. Recently, chimeric antigen receptor (CAR) T-cell therapy has been successfully applied in the treatment of B-cell malignancies, underscoring its great potential in antitumor therapy. However, functional challenges of CAR-T cell therapy, especially in solid tumors, remain. Here, we describe cancer-immunity phenotypes from a clonal-stromal-immune perspective and elucidate mechanisms of T-cell exhaustion that contribute to tumor immune evasion. Then we assess the functional challenges of CAR-T cell therapy, including cell trafficking and infiltration, targeted-recognition and killing of tumor cells, T-cell proliferation and persistence, immunosuppressive microenvironment and self-control regulation. Finally, we delineate tumor precision informatics and advancements in engineered CAR-T cells to counteract inherent challenges of the CAR-T cell therapy, either alone or in combination with traditional therapeutics, and highlight the therapeutic potential of this approach in future tumor precision treatment.

Purpose: Long noncoding RNAs have been implicated in gliomagenesis, but their mechanisms of action are mainly undocumented. Through public glioma mRNA expression data sets, we found that NEAT1 was a potential oncogene. We systematically analyzed the clinical significance and mechanism of NEAT1 in glioblastoma. Experimental Design: Initially, we evaluated whether NEAT1 expression levels could be regulated by EGFR pathway activity. We subsequently evaluated the effect of NEAT1 on the WNT/β-catenin pathway and its target binding gene. The animal model supported the experimental findings. Results: We found that NEAT1 levels were regulated by EGFR pathway activity, which was mediated by STAT3 and NFκB (p65) downstream of the EGFR pathway. Moreover, we found that NEAT1 was critical for glioma cell growth and invasion by increasing β-catenin nuclear transport and downregulating ICAT, GSK3B, and Axin2. Taken together, we found that NEAT1 could bind to EZH2 and mediate the trimethylation of H3K27 in their promoters. NEAT1 depletion also inhibited GBM cell growth and invasion in the intracranial animal model. Conclusions: The EGFR/NEAT1/EZH2/β-catenin axis serves as a critical effector of tumorigenesis and progression, suggesting new therapeutic directions in glioblastoma. Clin Cancer Res; 24(3); 684–95. ©2017 AACR.

Background The communication between carcinoma associated fibroblasts (CAFs) and cancer cells facilitate tumor metastasis. In this study, we further underlying the epigenetic mechanisms of CAFs feed the cancer cells and the molecular mediators involved in these processes. Methods MCF-7 and MDA-MB-231 cells were treated with CAFs culture conditioned medium, respectively. Cytokine antibody array, enzyme-linked immunosorbent assay, western blotting and immunofluorescence were used to identify the key chemokines. Chromatin immunoprecipitation and luciferase reporter assay were performed to explore the transactivation of target LncRNA by CAFs. A series of in vitro assays was performed with RNAi-mediated knockdown to elucidate the function of LncRNA. An orthotopic mouse model of MDA-MB-231 was conducted to confirm the mechanism in vivo. Results Here we reported that TGF-β1 was top one highest level of cytokine secreted by CAFs as revealed by cytokine antibody array. Paracrine TGF-β1 was essential for CAFs induced EMT and metastasis in breast cancer cells, which is a crucial mediator of the interaction between stromal and cancer cells. CAF-CM significantly enhanced the HOTAIR expression to promote EMT, whereas treatment with small-molecule inhibitors of TGF-β1 attenuated the activation of HOTAIR. Most importantly, SMAD2/3/4 directly bound the promoter site of HOTAIR, located between nucleotides -386 and -398, -440 and -452, suggesting that HOTAIR was a directly transcriptional target of SMAD2/3/4. Additionally, CAFs mediated EMT by targeting CDK5 signaling through H3K27 tri-methylation. Depletion of HOTAIR inhibited CAFs-induced tumor growth and lung metastasis in MDA-MB-231 orthotopic animal model. Conclusions Our findings demonstrated that CAFs promoted the metastatic activity of breast cancer cells by activating the transcription of HOTAIR via TGF-β1 secretion, supporting the pursuit of the TGF-β1/HOTAIR axis as a target in breast cancer treatment. Electronic supplementary material The online version of this article (10.1186/s12943-018-0758-4) contains supplementary material, which is available to authorized users.

The epidermal growth factor receptor (EGFR) frequently undergoes high-level genomic amplification and variant III (vIII) deletion in adult glioblastoma. MicroRNAs (miRNAs) are recognized to participate in gene expression regulation. We found that miR-524-3p and miR-524-5p were suppressed in the classical molecular subtype of glioblastoma (GBM) from Chinese Glioma Genome Atlas (CGGA) data, and the suppression was associated with EGFR overexpression and EGFRvIII mutation. These two miRNAs improved overall survival time of patients with glioma, and their overexpression could restrain glioma cell migration, proliferation, and cell cycle, and control tumor formation in vivo. Interestingly, both of the miRNAs had a synergistic inhibitory effect on glioma cells. Furthermore, we confirmed that EGFR amplification/EGFRvIII mutation can repress the expression of Pri-miR-524 by histone modification. MiR-524-3p and miR-524-5p inhibited TGF/β, Notch and the Hippo pathway by targeting Smad2, Hes1 and Tead1, respectively; these pathways repressed their common downstream transcription factor, C-myc. More interestingly, C-myc bound to the promoter region of EGFR/EGFRvIII and activated its expression. These findings indicate that miR-524 mediates the EGFR/EGFRvIII stimulating effect. It may serve as a potential therapeutic agent and classical-specific biomarker for the development of glioma.

SNORD47 is a member of the C/D box small nucleolar RNAs, which have been implicated in cancer development. We intended to investigate the therapeutic potential of SNORD47 in glioma. We found that the expression of SNORD47 was downregulated in glioma tissues samples and inversely associated with advanced tumor stage (WHO grade IV). Kaplan-Meier survival analysis revealed that glioma patients with high SNORD47 expression had longer overall survival than those with low SNORD47 expression. SNORD47 suppressed the proliferation of glioma cells and induced G2 phase arrest. In addition, upregulation of SNORD47 suppressed invasion and epithelial-mesenchymal transition in glioma cells, and combination treatment with lenti-SNORD47 could augment the anti-tumor effect of temozolomide. These results showed that SNORD47 acted as a tumor suppressor in glioma, and provided the potential anti-tumor function in glioma treatment.

HOTAIR is a tumor promoting long non-coding RNA (lncRNA) with roles in multiple cancers. However, the role of HOTAIR in glioma has not been well charaterized. Genes that positively correlated with HOTAIR were identified from the Chinese Glioma Genome Atlas and constructed into an interacting network. In total, 18 genes with P-values

Worldwide, glioblastoma (GBM) is the most lethal and frequent intracranial tumor. Despite decades of study, the overall survival of GBM patients remains unchanged. epidermal growth factor receptor (EGFR) amplification and gene mutation are thought to be negatively correlated with prognosis. In this study, we used proteomics to determine that UBXN1 is a negative downstream regulator of the EGFR mutation vIII (EGFRvIII). Via bioinformatics analysis, we found that UBXN1 is a factor that can improve glioma patients' overall survival time. We also determined that the down-regulation of UBXN1 is mediated by the upregulation of H3K27me3 in the presence of EGFRvIII. Because NF-κB can be negatively regulated by UBXN1, we believe that EGFRwt/vIII activates NF-κB by suppressing UBXN1 expression. Importantly, we used the latest genomic editing tool, CRISPR/Cas9, to knockout EGFRwt/vIII on exon 17 and further proved that UBXN1 is negatively regulated by EGFRwt/vIII. Furthermore, knockout of EGFR/EGFRvIII could benefit GBM in vitro and in vivo, indicating that CRISPR/Cas9 is a promising therapeutic strategy for both EGFR amplification and EGFR mutation-bearing patients.

The ubiquitin-conjugating enzyme 2C (UBE2C) is the key component in the ubiquitin proteasome system (UPS) by partnering with the anaphase-promoting complex (APC/C). A high UBE2C protein expression level has been reported in various types of human tumors. However, little is known about the precise mechanism by which UBE2C expression is downregulated in gastric cancer. We found in MGC-803 and SGC-7901 gastric cancer cells UBE2C-deficient G2/M phase arrest in the cell cycle and subsequently decreased gastric adenocarcinoma tumorigenesis. In the previous study, we identified Aurora-A (AURKA) as the hub gene of the gastric cancer linkage network based genome-wide association study (eGWAS). Furthermore, knockdown of UBE2C using siRNA markedly reduced the level of phosphorylation AURKA (p-AURKA) via Wnt/β-catenin and PI3K/Akt signaling pathways suppressed the occurrence and development of gastric cancer. Additionally, the expression of E-cadherin was up-regulated and N-cadherin was down-regulated in response to UBE2C knockdown and inhibits epithelial-mesenchymal transition (EMT). Collectively, our data suggest that the activity of AURKA might be regulated by UBE2C through regulating the activity of APC/C. UBE2C may be a new marker in the diagnosis of gastric cancer and may be a potential therapeutic target for the treatment of gastric adenocarcinoma.

Epigenetics is a discipline that studies heritable changes in gene expression that do not involve altering the DNA sequence. Over the past decade, researchers have shown that epigenetic regulation plays a momentous role in cell growth, differentiation, autoimmune diseases, and cancer. The main epigenetic mechanisms include the well-understood phenomenon of DNA methylation, histone modifications, and regulation by non-coding RNAs, a mode of regulation that has only been identified relatively recently and is an area of intensive ongoing investigation. It is generally known that the majority of human transcripts are not translated but a large number of them nonetheless serve vital functions. Non-coding RNAs are a cluster of RNAs that do not encode functional proteins and were originally considered to merely regulate gene expression at the post-transcriptional level. However, taken together, a wide variety of recent studies have suggested that miRNAs, piRNAs, endogenous siRNAs, and long non-coding RNAs are the most common regulatory RNAs, and, significantly, there is a growing body of evidence that regulatory non-coding RNAs play an important role in epigenetic control. Therefore, these non-coding RNAs (ncRNAs) highlight the prominent role of RNA in the regulation of gene expression. Herein, we summarize recent research developments with the purpose of coming to a better understanding of non-coding RNAs and their mechanisms of action in cells, thus gaining a preliminary understanding that non-coding RNAs feed back into an epigenetic regulatory network.

Objective: Mesenchymal subtype of glioblastoma (mesGBM) is a refractory disease condition characterized by therapeutic failure and tumor recurrence. Hyperactive transforming growth factor-β (TGF-β) signaling could be a signature event in mesGBM, which leads to dysregulation of downstream targets and contribute to malignant transformation. In this study we aimed to investigate the hyperactive TGFβ signaling-mediated pathogenesis and possible downstream targets for the development of novel therapeutic interventions for mesGBM. Methods: GBM-BioDP is an online resource for accessing and displaying interactive views of the TCGA GBM data set. Transcriptomic sequencing followed by bioinformatic analysis was performed to identify dysregulated microRNAs. Target prediction by MR-microT and dual luciferase reporter assay were utilized to confirm the predicted target of novel_miR56. CCK-8 assays was used to assesse cell viability. The miRNA manipulation was proceeded by cell transfection and lentivirus delivery. A plasmid expressing GFP-LC3 was introduced to visualize the formation of autophagosomes. Orthotopic GBM model was constructed for in vivo study. Results: TGFβ1 and TGFβ receptor type II (TβRII) were exclusively upregulated in mesGBM (P < 0.01). Dysregulated miRNAs were identified after LY2109761 (a TβRI/II inhibitor) treatment in a mesGBM-derived cell line, and novel_miR56 was selected as a promising candidate for further functional verification. Novel_miR56 was found to potentially bind to PRAS40 via seed region complementarity in the 3' untranslated region, and we also confirmed that PRAS40 is a direct target of novel_miR56 in glioma cells. In vitro, over expression of novel_miR56 in tumor cells significantly promoted proliferation and inhibited autophagy (P < 0.05). The expression levels of P62/SQSTM was significantly increased accompanied by the decrease of BECN1 and LC3B-II/I, which indicated that autophagic activity was reduced after novel_miR56 treatment. In addition, over expression of novel_miR56 also promoted tumor growth and inhibited autophagy in vivo, which is associated with worse prognosis (P < 0.05). Conclusions: In summary, we provide novel insight into TGFβ signaling-mediated pathogenesis in mesGBM and TGFβ signaling-induced novel_miR56 may be a novel target for mesGBM management.

Simple Summary The current understanding of miRNA biology is greatly derived from studies on the guide strands and the passenger strands, also called miRNAs*, which are considered as carriers with no sense for long periods. As such, various studies alter the expression of guide strands by manipulating the expression of their primary transcripts or precursors, both of which are premature miRNAs. In this situation, the regulatory miRNA* species may interfere with the phenotypic interpretation against the target miRNA. However, such methods could manipulate the expression of two functionally synergistic miRNAs of the same precursor, leading to therapeutic potential against various diseases, including cancers. Premature miRNAs represent an underappreciated target reservoir and provide molecular targets for “one-two punch” against cancers. Examples of targetable miRNA precursors and available targeting strategies are provided in this review. Abstract Up-to-date knowledge regarding the biogenesis and functioning of microRNAs (miRNAs) has provided a much more comprehensive and concrete view of miRNA biology than anyone ever expected. Diverse genetic origins and biogenesis pathways leading to functional miRNAs converge on the synthesis of ≈21-nucleotide RNA duplex, almost all of which are processed from long premature sequences in a DICER- and/or DROSHA-dependent manner. Formerly, it was assumed that one mature strand of the duplex is preferentially selected for entry into the silencing complex, and the paired passenger strands (miRNA*) are subjected to degradation. However, given the consolidated evidence of substantial regulatory activity of miRNA* species, currently, this preconception has been overturned. Here, we see the caveat and opportunity toward exogenously manipulating the expression of premature miRNA, leading to simultaneous upregulation or downregulation of dual regulatory strands due to altered expressions. The caveat is the overlooked miRNA* interference while manipulating the expression of a target miRNA at the premature stage, wherein lies the opportunity. If the dual strands of a pre-miRNA function synergistically, the overlooked miRNA* interference may inversely optimize the therapeutic performance. Insightfully, targeting the premature miRNAs may serve as the “one-two punch” against diseases, especially cancers, and this has been discussed in detail in this review.

The Chinese Glioma Cooperative Group (CGCG) Guideline Panel for adult diffuse gliomas provided recommendations for diagnostic and therapeutic procedures. The Panel covered all fields of expertise in neuro-oncology, i.e. neurosurgeons, neurologists, neuropathologists, neuroradiologists, radiation and medical oncologists and clinical trial experts. The task made clearer and more transparent choices about outcomes considered most relevant through searching the references considered most relevant and evaluating their value. The scientific evidence of papers collected from the literature was evaluated and graded based on the Oxford Centre for Evidence-based Medicine Levels of Evidence and recommendations were given accordingly. The recommendations will provide a framework and assurance for the strategy of diagnostic and therapeutic measures to reduce complications from unnecessary treatment and cost. The guideline should serve as an application for all professionals involved in the management of patients with adult diffuse glioma and also as a source of knowledge for insurance companies and other institutions involved in the cost regulation of cancer care in China.

MicroRNAs (miRNAs) are able to function as either oncogenes or tumor suppressor genes in tumorigenesis, and have been proposed as novel targets for anticancer treatment. It has previously been suggested that miRNAs have important roles in the initiation and progression of glioblastoma; however, the effects of miR‑566 in glioblastoma are currently unclear. The present study aimed to demonstrate that miR-566 can modulate vascular endothelial growth factor (VEGF) by targeting Von Hippel‑Lindau (VHL) in glioblastoma in vitro and in vivo by inhibiting the expression of miR-566. Glioblastoma is a highly vascularized tumor, which exhibits increased expression of angiogenic factors, including VEGF, which are crucial in the process of glioblastoma angiogenesis. Existing research has demonstrated that VHL is a tumor suppressor gene that is associated with various tumors. In addition, VHL is able to regulate the expression of VEGF by promoting the degradation of hypoxia‑inducible factor‑1α via ubiquitination. It has been predicted, using bioinformatics, that the VHL gene is regulated by miR‑566. Therefore, the present study hypothesized that miR‑566 may regulate VEGF expression by targeting VHL during the angiogenic process of glioblastoma multiforme. The results of the present study demonstrated that inhibition of miR‑566 expression increases the expression levels of VHL, decreases the expression levels of VEGF, and inhibits the invasive and migratory abilities of glioblastoma. In addition, VHL was identified as a functional target of miR‑566.

Long noncoding RNAs (lncRNAs) have emerged as new regulatory molecules implicated in diverse biological processes, including therapeutic resistance. However, the mechanisms underlying lncRNA-mediated temozolomide (TMZ) resistance in glioblastoma (GBM) remain largely unknown. To illustrate the role of lncRNA in TMZ resistance, we induce TMZ-resistant GBM cells, perform a lncRNA microarray of the parental and TMZ-resistant cells, and find an unreported lncRNA in GBM, lnc-TALC (temozolomide-associated lncRNA in glioblastoma recurrence), correlated with TMZ resistance via competitively binding miR-20b-3p to facilitate c-Met expression. A phosphorylated AKT/FOXO3 axis regulated lnc-TALC expression in TMZ-resistant GBM cells. Furthermore, lnc-TALC increased MGMT expression by mediating the acetylation of H3K9, H3K27 and H3K36 in MGMT promoter regions through the c-Met/Stat3/p300 axis. In clinical patients, lnc-TALC is required for TMZ resistance and GBM recurrence. Our results reveal that lnc-TALC in GBM could serve as a therapeutic target to overcome TMZ resistance, enhancing the clinical benefits of TMZ chemotherapy., Temozolomide resistance in glioblastoma is associated with MGMT overexpression. Here, the authors identify a lncRNA that is a competitive endogenous RNA for miR-20b-3p, which causes c-Met activation to modulate acetylation of histone H3 on MGMT promoter through Stat3/p300 complex to increase MGMT expression and temozolomide resistance.

Glioblastoma multiforme (GBM) is a highly malignant and notably aggressive primary tumour. Variant III of the epidermal growth factor receptor (EGFRvIII) is one of the most common types of variants in GBM, and serves an important role in tumour invasion, proliferation and treatment resistance. In the present study, statistical analyses were performed on data from 57 patients with GBM, and polymerase chain reaction detection was conducted on the tumour tissues from 32 of these patients. The results indicated that the EGFRvIII mutation was significantly associated with tumour malignancy. Human GBMU87-EGFRvIII cell lines were cultured and treated with radiosurgery and temozolomide individually, or with combined radiosurgery and temozolomide treatment. In vitro and in vivo experimental methods were used to detect the expression levels of Ki-67 and EGFRvIII. As verified in the present study, the EGFRvIII mutation is positively correlated with the malignancy of tumours, and combined radiosurgery and temozolomide therapy may inhibit the invasion and proliferation abilities of U87-EGFRvIII more effectively than treatment alone.

Air pollution plays a role in cancer risk, particularly in lung cancer, which is the leading cause of cancer-related mortality worldwide. Diesel exhaust particles (DEPs), a component of diesel exhaust products, is a complex mixture of particle compounds that include a large number of known and suspected human carcinogens. Historically, lung cancer, which is associated with DEPs, has been the focus of attention as a health risk in human and animal studies. However, the mechanism by which DEPs cause lung cancer remains unclear. The present study reports that DEPs increased miR-21 expression and then activated the PTEN/PI3K/AKT pathway in human bronchial epithelial (HBE) cells, which may serve as an important carcinogenic mechanism. However, the data revealed that short-term exposure to a high DEP concentration did not cause evident cell carcinogenesis in HBE cells.

// Xuan Zhou 1, 2, * , Yu Ren 3, * , Jing Zhang 4, * , Chuanbao Zhang 5, * , Kailiang Zhang 1, 6 , Lei Han 1 , Lingping Kong 2 , Jianwei Wei 1 , Luyue Chen 1 , Jingxuan Yang 6 , Qixue Wang 1 , Jianning Zhang 1 , Yuqi Yang 7 , Tao Jiang 5 , Min Li 2, 6 , Chunsheng Kang 1 1 Department of Neurosurgery, Tianjin Medical University General Hospital, Laboratory of Neuro-oncology, Tianjin Neurological Institute, Tianjin 300052, China 2 The Department of Otorhinolaryngology and Maxillofacial Oncology, Tianjin Medical University Cancer Institute & Hospital, Key Laboratory of Cancer Prevention and Therapy, Tianjin Cancer Institute, National Clinical Research Center of Cancer, Tianjin 300060, China 3 Tianjin Research Center of Basic Medical Science, Tianjin Medical University, Tianjin 300070, China 4 Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China 5 Beijing Neurosurgical Institute, Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing 100050, China 6 Department of Medicine, Department of Surgery, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104,USA 7 Department of Pharmacology, Tianjin Medical University, Tianjin 300070, China * These authors have contributed equally to this work Correspondence to: Chunsheng Kang, e-mail: kang97061@gmail.com Tao Jiang, e-mail: jiangtao369@sohu.com Min Li, e-mail: Min-Li@ouhsc.edu Keywords: HOTAIR, NLK (Nemo-like kinase), β-catenin, PRC2 (Polycomb repressive complex 2), Glioblastoma Received: December 01, 2014 Accepted: January 28, 2015 Published: March 21, 2015 ABSTRACT HOTAIR is a negative prognostic factor and is overexpressed in multiple human cancers including glioblastoma multiform (GBM). Survival analysis of Chinese Glioma Genome Atlas (CGGA) patient data indicated that high HOTAIR expression was associated with poor outcome in GBM patients. NLK (Nemo-like kinase), a negative regulator of the β-catenin pathway, was negatively correlated with HOTAIR expression. When the β-catenin pathway was inhibited, GBM cells became susceptible to cell cycle arrest and inhibition of invasion. Introduction of the HOTAIR 5’ domain in human glioma-derived astrocytoma induced β-catenin. An intracranial animal model was used to confirm that HOTAIR depletion inhibited GBM cell migration/invasion. In the orthotopic model, HOTAIR was required for GBM formation in vivo . In summary, HOTAIR is a potential therapeutic target in GBM.

The identification of single or less genes based on mRNA expression as clinical diagnostic markers for glioblastoma (GBM) remains a challenge. Recent data have shown the potential oncogenic role and prognostic significance of EZH2 in several human cancers. However, the clinical signature and further mechanisms of EZH2 function in gliomagenesis are still poorly understood. In this study, we found that increased EZH2 expression was associated with tumor grade. High expression of EZH2 in GBM was determined to be a strong and independent predictor of short overall survival. Further, we screened EZH2 targets and associated genes in GBM. Repression of EZH2 induced cell cycle arrest and inhibited tumor growth in vivo. This event represents a positive feedback loop with β-catenin/TCF4 and STAT3 signaling. Taken together, EZH2 could be an independent prognostic factor and potential therapeutic target for GBM.

The long non-coding RNA Hox transcript antisense intergenic RNA (HOTAIR) was recently implicated in breast cancer metastasis and is predictive of poor prognosis in colorectal and pancreatic cancers. We recently discovered that HOTAIR is a cell cycle-related lncRNA in human glioma, and its expression is closely associated with glioma staging and poor prognosis. Although lysine specific demethylase 1 (LSD1) and polycomb repressive complex 2 (PRC2) have been demonstrated to be functional targets of HOTAIR, how HOTAIR regulates glioma cell cycle progression remains largely unknown. In this study, we found that EZH2 (predominant PRC2 complex component) inhibition blocked cell cycle progression in glioma cells, consistent with the effects elicited by HOTAIR siRNA. However, the inhibition of LSD1 did not affect cell cycle progression in glioma cells. These results suggest that HOTAIR might regulate cell cycle progression through EZH2. Our intracranial mice model also revealed delayed tumor growth in HOTAIR siRNA- and EZH2 inhibitor-treated groups. Moreover, in HOTAIR knock-down cell lines, the expression of the PRC2-binding domain of HOTAIR (5′ domain) but not of the LSD1-binding domain of HOTAIR (3′ domain) resulted in accelerated cell cycle progression. In conclusion, HOTAIR promotes cell cycle progression in glioma as a result of the binding of its 5′ domain to the PRC2 complex.

Glioblastoma (GBM) is an aggressive, highly invasive, vascularized tumor with a long-term survival of

Abnormalities in signal transducer and activator of transcription 3 (STAT3) are involved in the oncogenesis of oral squamous cell carcinoma (OSCC). MicroRNA-21 (miR-21) is an important gene expression regulator to OSCC. miR-21 induction by STAT3 has been reported in multiple human cancers. In the present study, we found that STAT3 (-/p) expression was positively correlated with miR-21 in 60 OSCC samples. A reporter gene assay showed that miR-21 overexpression was dependent on STAT3 activation. WP1066, a small molecular inhibitor of STAT3, was used to suppress STAT3 expression in OSCC cells. TSCCA and TCA8113 showed reduction in tumor cell proliferation, invasion ability and miR-21 expression by WP1066 treatment. In addition, the expression of miR-21 target proteins [programmed cell death 4 (PDCD4), tissue inhibitor of metalloproteinase 3 (TIMP-3) and phosphatase and tensin homolog (PTEN)] was upregulated. Restored STAT3 expression by IL-6 induced miR-21 overexpression, which further confirmed the correlation between STAT3 and miR-21. WP1066 inhibited tumor growth and induced tumor cell apoptosis in the TSCCA xenograft tumor model. Western blotting and immunohistochemistry staining indicated that STAT3 (-/p), Ki67, Bcl-2 and MMP-2 expressions decreased in the WP1066-treated group; PDCD4, TIMP-3 and PTEN expression increased simulta-neously. The present study provides evidence that targeting STAT3 could regulate OSCC cell growth in a miR-21-dependent manner and WP1066 could be a novel candidate drug to treat OSCC by inhibiting STAT3/miR-21 axis.

Previous studies identified the frequent loss of adherens junction-associated protein 1 (AJAP1) expression in glioblastoma (GBM) and its correlation with worse survival. AJAP1 may suppress glioma cell migration, which plays an important role in tumor progression in malignant gliomas such as GBM. However, the role of AJAP1 in cell cycle arrest or apoptosis and resistance to chemotherapy remains unclear. Based on microarray screening results, quantitative PCR and luciferase plasmid reporter constructs were used to evaluate the possible regulatory role of AJAP1 on MAGEA2 expression and function. Cell death assays, TUNEL and other markers of apoptosis were utilized to detect cell apoptosis. Restoration of AJAP1 expression in glioma cells was analyzed after temozolomide exposure. AJAP1 suppressed the expression of MAGEA2 and inhibited the transcriptional activity of MAGEA2 in glioma cells. As AJAP1 expression decreased MAGEA2 protein expression apoptosis increased moderately. Consistent with increased cell death, the induced loss of MAGEA2 expression correlated with increased caspase 3/7 activity, BCL2/BAX ratio and TUNEL signal. AJAP1 expression enhanced cell death in the presence of temozolomide. This study suggests AJAP1 may also function as a pro-apoptotic factor and potentiate cell death by temozolomide in glioma cells. This effect may be partially explained by AJAP1-mediated gene regulation of MAGEA2.

EGFR amplification and mutations are the most common oncogenic events in GBM. EGFR overexpression correlates with GBM invasion, but the underlying mechanisms are poorly understood. In a previous study, we showed that AJAP1 is involved in regulating F-actin to inhibit the invasive ability of GBM. In addition, in a GBM cell line, the AJAP1 promoter was highly bound by H3K27me3 and, through bioinformatics analysis, we found that AJAP1 expression was negatively correlated with EGFR. In this study, we found that the pathway downstream of EGFR had a higher activation level in GBM cell lines, which led to excessive tumor suppressor silencing. Therefore, we deduced that in glioma cells, the pathway downstream of EGFR remodels the cytoskeleton via AJAP1 epigenetic silencing to enhance invasion. Furthermore, MK2206 reversed AJAP1 downregulation by inhibiting the EGFR pathway. In vivo, MK2206 also inhibited the proliferation and local invasion of 87-EGFRvIII. These data suggest that activation of the EGFR signal transduction pathway genetically silences anti-oncogenes to enhance GBM malignancy. MK2206 might be a promising therapeutic for EGFR/EGFRvIII-positive GBMs.

RNA is the intermediate link of central dogma. However, RNA is rarely used as a therapeutic target for its flexible structure and instability. CRISPR/Cas13a is reported as a powerful tool for RNA knockdown. The potential amplification of CRISPR/Cas13a in cancer cells could be further studied. Here we overexpressed the Cas13a protein by lenti-virus vectors in glioma and other cancer cells, and found out that crRNA-EGFP could induce the “collateral effect” after knocking down the target gene. EGFRvIII is a unique EGFR mutant subtype in glioma. CRISPR/Cas13a system could induce cell death of EGFRvIII overexpression glioma cells. Single cell and RNA-seq analysis confirmed the comprehensive RNA interference by CRISPR/Cas13a treatment. Furthermore, CRISPR/Cas13a system could inhibit the formation of glioma intracranial tumor in mice. Our results exhibit the comprehensive RNA interference of CRISPR/Cas13a system in cancer cells, and demonstrated the powerful tumor elimination potential of this system. Citation Format: Qixue Wang, Yunfei Wang, Yanli Tan, Chunsheng Kang. Comprehensive RNA interference induced by CRISPR/Cas13a gene editing system in human cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1246.

Background Long noncoding RNA Hox transcript antisense intergenic RNA (HOTAIR) has been characterized as a negative prognostic factor in breast and colon cancer patients. The clinical significance and function of HOTAIR in glioma remains unclear.

ceRNA networks play important roles in post-transcriptional regulation. Their dysregulation is common in cancer. However, ceRNA signatures are barely examined for mesenchymal glioblastoma characteristic of invasive and aggressive phenotypes. Here, we investigated the mRNAs in ceRNA networks (micNET) of glioblastoma by constructing a GBM ceRNA network, followed by being integrated with STRING protein interaction network. We report that six micNETs (TGFBR2, RUNX1, PPARG, ACSL1, GIT2 and RAP1B) signify mesenchymal GBM across multiple datasets. Patients with highly expressed micNET markers have poor response to TMZ chemotherapy. Mechanistically, the ceRNA interaction were identified between micNETs and miR181s family members. The inhibitor of TGFBR2, LY2109761, demonstrated tumor-suppressive effect on both primary cultured cell and PDX intracranial model. Thereby, the micNETs provide a promising translational significance in diagnosis of mesenchymal GBM as well as novel therapeutic targets. In conclusion, our study revealed that the ceRNA signature of mesenchymal glioblastoma was enriched in the TGF-β pathway and characterized this subtype in the mRNA-miRNA dimension. We identified that key micNETs signatures could be used to diagnose mesenchymal GBM and discovered that the TGF-β pathway is a potential therapeutic target for mesenchymal glioblastoma.

Summary Aims To identify molecular genetic factors that influence preoperative seizure occurrence and postoperative seizure control in patients with low-grade gliomas (LGGs). Methods Fifty-four WHO grade II astrocytomas were used for microarray analysis under strict inclusion criteria. The primary endpoint was seizure control at 12 months after surgery. Biological processes were investigated by gene ontology (GO) analysis. Quantitative RT-PCR and immunohistochemistry were used to validate key genes. Results Differentially expressed genes correlated with seizure occurrence failed to significantly distinguish patients with and without a history of seizures. With respect to postoperative seizure control, a transcript profile of 92 genes was identified, which successfully separated patients with good and poor seizure prognosis. GO analysis revealed that the most striking overrepresentation of genes was found in a category of anti-apoptotic genes and their regulation. Increased expression was also observed for genes involved in immune and inflammatory responses. BCL2A1 was proven to be a novel marker associated with seizure prognosis. Conclusion Increased anti-apoptotic activity of tumor cells appears to contribute to seizure recurrence after surgery in patients with LGGs. These findings provide insights that may lead to the development of effective treatment strategies for prolonging the survival of patients with LGG in the future.

Recently, many studies have found that the miR-106b ~25 cluster plays an oncogenic role in tumor progression. However, the precise role of each microRNAs (miRNAs) in the cluster is not yet clear. In the present study, we examined the expression of miR-106b in glioma samples and a tissue microarray by real-time PCR and in situ hybridization (ISH), respectively, finding that miR-106b is overexpressed in the majority of gliomas. Meanwhile, the expression of miR-106b was positively correlated with tumor grade (p < 0.05). The transfection of a miR-106b anti-sense oligonucleotide (ASON) into three human glioma cell lines (U251, LN229 and TJ905) suppressed the proliferation of these cells. Moreover, the growth of xenograft tumors in nude mice treated with miR-106b ASON was significantly impaired. A bioinformatics analysis predicted that RBL2 may be the target of miR-106b, and dual-luciferase reporter assays identified RBL2, but not RB1 or RBL1, as a target of miR-106b. These results suggest that miR-106b facilitates glioma cell growth by promoting cell cycle progression through the negative regulation of RBL2.

MicroRNAs are strongly implicated in cancer but their specific roles and functions in the major cancers have yet to be fully elucidated. In this study, we defined the expression and function of miR-137, which we found to be downregulated in glioma samples and glioma cells by qRT-PCR. Ectopic expression of miR-137 in glioma cell lines inhibited proliferation and invasion. Using computational and expression analysis, Cox-2 was identified as a candidate target of miR-137. Reporter assay with 3′UTR of Cox-2 cloned downstream of the luciferase gene showed reduced luciferase activity in the presence of miR-137, providing strong evidence that miR-137 was a direct regulator of Cox-2. Expression analysis further revealed that Cox-2 was elevated in glioma and associated with survival of patients. Furthermore, we observed that Cox-2 knockdown resulted in effects similar to those with miR-137 transfection in glioma cells. In conclusion, our study demonstrates that miR-137 deregulation is common in glioma, and restoration of its function inhibits cell proliferation and invasion, suggesting that miR-137 may act as a tumour suppressor.

Epidermal Growth Factor like domain 7 (EGFL7), also known as Vascular Endothelial-statin (VE-statin), is a secreted angiogenic factor. Recent data have demonstrated the potential oncogenic role and prognostic significance of EGFL7 in several human cancers. However, the clinical signature and further mechanisms of EGFL7's function in gliomagenesis are poorly understood. In the present study, we found that increased EGFL7 expression was associated with tumor grade. High expression of EGFL7 in EGFRvIII-positive glioblastoma multiforme (GBM) was determined to be a strong and independent risk factor for reduced life expectancy. EGFRvIII cells can secrete the EGFL7 protein to improve the activity of the β-catenin/TCF4 Transcription complex in EGFRwt cells, thus promoting their own EGFL7 expression. Our research demonstrates that oncogenic activation of EGFRwt in GBM is likely maintained by a continuous EGFL7 autocrine flow line, and may be an attractive target for therapeutic intervention.

Extensive heterogeneity is a defining hallmark of glioblastoma multiforme (GBM) at the cellular and molecular levels. EGFRvIII, the most common EGFR mutant, is expressed in 24-67% of cases and strongly indicates a poor survival prognosis. By co-expressing EGFRvIII and EGFRwt, we established an EGFRvIII/wt heterogenic model. Using this approach, we confirmed that a mixture of EGFRvIII and EGFRwt at a certain ratio could clearly enhance tumor growth in vitro and in vivo compared with EGFRwt cells, thereby indicating that EGFRvIII cells promote tumor growth. Furthermore, we demonstrated that the EGFRvIII cells could support the growth of EGFRwt cells by secreting growth factors, thus acting as the principal source for maintaining tumor survival. F25P preproinsulin effectively reduced the concentrations of EGF, VEGF, and MMP-9 in the blood of tumor-bearing mice by competitively inhibiting the endoplasmic reticulum signal peptidase and increased the overall survival in orthotopic models. Taken together, our results provided an effective therapy of F25P preproinsulin in the EGFRvIII/wt heterogenic model.

BACKGROUND: More reliable clinical outcome prediction is required to better guide more personalized treatment for patients with primary glioblastoma multiforme (GBM). The objective of this study was to identify a microRNA expression signature to improve outcome prediction for patients with primary GBM. METHODS: A cohort of Chinese patients with primary GBM (n = 82) was analyzed using whole-genome microRNA expression profiling with patients divided into a training set and a testing set. Cox regression and risk-score analyses were used to develop a 5-microRNA signature using 41 training samples. The signature was validated in 41 other test samples, in an independent cohort of 35 patients with GBM, and in the Cancer Genome Atlas data set. RESULTS: Patients who had high risk scores according to the 5-microRNA signature had poor overall survival and progression-free survival compared with patients who had low risk scores. Multivariate Cox analysis indicated that the 5-microRNA signature was an independent prognostic biomarker after adjusting for other clinicopathologic and genetic factors, such as extent of resection, temozolomide chemotherapy, preoperative Karnofsky performance status score, isocitrate dehydrogenase 1 (IDH1) mutation, and O-6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status. CONCLUSIONS: The 5-microRNA signature was identified as an independent risk predictor that identified patients who had a high risk of unfavorable outcome, demonstrating its potential for personalizing cancer management. The authors concluded that this signature should be evaluated in further prospective studies. Cancer 2013. © 2012 American Cancer Society.

Brainstem glioma (BSG) is an entity which commonly occurs in pediatric patients and carries a dismal prognosis. However, the category of adult BSG has displayed considerably benign biological behavior, thus providing a unique perspective to comparatively understand the malignant features of pediatric BSG. microRNAs (miRNAs) have been associated with cancer development and progression. To identify miRNAs specifically involved in the acquisition of malignant progression of pediatric BSG, we analyzed the miRNA expression profiles in orthotopic models which could simulate the BSG heterogeneity by microarrays. Our research revealed that miR-20a and miR-106b (known to be closely related) were the two most robust upregulated miRNAs in pediatric BSG compared to adult subtype. Furthermore, the two types of human BSG tissue were utilized to verify the microarray data by qRT-PCR and in situ hybridization. The results indicated good consistency with that of the microarray method. In conclusion, our studies provide evidence that miR-20a and miR-106b may serve as putative causative involvement of malignant progression of pediatric BSG, thereby serving as likely novel targets for constraining the rapid fatal course of pediatric BSG.

The invasive behavior of glioblastoma multiforme (GBM) cells is one of the most important reasons for the poor prognosis of this cancer. For invasion, tumor cells must acquire an ability to digest the extracellular matrix and infiltrate the normal tissue bordering the tumor. Preventing this by altering effector molecules can significantly improve a patient's prognosis. Accumulating evidence suggests that miRNAs are involved in multiple biological functions, including cell invasion, by altering the expression of multiple target genes. The expression levels of miR-218 correlate with the invasive potential of GBM cells. In this study, we found that miR-218 expression was low in glioma tissues, especially in GBM. The data showed an inverse correlation in 60 GBM tissues between the levels of miR-218 and MMP mRNAs (MMP-2, -7 and -9). Additionally, ectopic expression of miR-218 suppressed the invasion of GBM cells whereas inhibition of miR-218 expression enhanced the invasive ability. Numerous members of the MMP family are downstream effectors of the Wnt/LEF1 pathway. Target prediction databases and luciferase data showed that LEF1 is a new direct target of miR-218. Importantly, western blot assays demonstrated that miR-218 can reduce protein levels of LEF1 and MMP-9. We, therefore, hypothesize that miR-218 directly targets LEF1, resulting in reduced synthesis of MMP-9. Results suggest that miR-218 is involved in the invasive behavior of GBM cells and by targeting LEF1 and blocking the invasive axis, miR-218-LEF1-MMPs, it may be useful for developing potential clinical strategies.