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Open Access Original Article Issue
Omics-based integrated analysis identified ATRX as a biomarker associated with glioma diagnosis and prognosis
Cancer Biology & Medicine 2019, 16(4): 784-796
Published: 01 November 2019
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Objective

ATRX is a multifunctional protein that is tightly regulated by and implicated in transcriptional regulation and chromatin remodeling. Numerous studies have shown that genetic alterations in ATRX play a significant role in gliomas. This study aims to further determine the relationship between ATRX and glioma prognosis and identify possible mechanisms for exploring 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 difference in ATRX mutations in high- and low-grade gliomas. An online analysis of the TCGA glioma datasets using the cBioPortal platform was performed to study the relationship between ATRX mutations and IDH1, TP53, CDKN2A and CDKN2B mutations in the corresponding TCGA glioma dataset. In combination with clinical pathology data, the biological significance of the relationships were analyzed. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses and annotations of all adjacent genes in the network were performedin 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 nodes were 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, which co-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 significantly associated with multiple important molecular events, such as ZNF274 and FDXR at mRNA and protein levels. A functional cluster analysis revealed that these genes played a role in chromatin binding and P53, and a link was observed between ATRX and IDH1 and TP53 in the interaction network. ATRX and TP53 are important nodes in the network and have potential links with the blood oxygen imbalance.

Conclusions

ATRX mutations have clinical implications for the molecular diagnosis of gliomas and can provide diagnostic and prognostic information for gliomas. ATRX is expected to serve as a new therapeutic target.

Open Access Review Issue
Expert opinion on translational research for advanced glioblastoma treatment
Cancer Biology & Medicine 2023, 20(5): 344-352
Published: 05 June 2023
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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.

Research Article Issue
Systemic delivery of microRNA for treatment of brain ischemia
Nano Research 2021, 14(9): 3319-3328
Published: 26 April 2021
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Brain ischemia is the second leading cause of death and the third leading cause of disability in the world. Systemic delivery of microRNA, a class of molecules that regulate the expression of cellular proteins associated with angiogenesis, cell growth, proliferation and differentiation, holds great promise for the treatment of brain ischemia. However, their therapeutic efficacy has been hampered by poor delivery efficiency of microRNA. We report herein a platform technology based on microRNA nanocapsules, which enables their effective delivery to the disease sites in the brain. Exemplified by microRNA-21, intravenous injection of the nanocapsules into a rat model of cerebral ischemia could effectively ameliorate the infarct volume, neurological deficit and histopathological severity.

Open Access Original Article Issue
TGFβ signaling-induced miRNA participates in autophagic regulation by targeting PRAS40 in mesenchymal subtype of glioblastoma
Cancer Biology & Medicine 2020, 17(3): 664-675
Published: 15 August 2020
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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.

Open Access Original Article Issue
Boosting of the enhanced permeability and retention effect with nanocapsules improves the therapeutic effects of cetuximab
Cancer Biology & Medicine 2020, 17(2): 433-443
Published: 15 May 2020
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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.

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