RPN2 is targeted by miR-181c and mediates glioma progression and temozolomide sensitivity via the wnt/β-catenin signaling pathway

Leu promotes C2C12 cell differentiation by regulating the GSK3β/β-catenin signaling pathway through facilitating the interaction between SESN2 and RPN2

BACKGROUND

Leucine (Leu) is an essential amino acid that facilitates skeletal muscle satellite cell differentiation, yet its mechanism remains underexplored. Sestrin2 (SESN2) serves as a Leu sensor, binding directly to Leu, while ribophorin II (RPN2) acts as a signaling factor in multiple pathways. This study aimed to elucidate Leu's impact on mouse C2C12 cell differentiation and skeletal muscle injury repair by modulating RPN2 expression through SESN2, offering a theoretical foundation for clinical skeletal muscle injury prevention and treatment.

RESULTS

Leu addition promoted C2C12 cell differentiation compared to the control, enhancing early differentiation via myogenic determinant (MYOD) up-regulation. Sequencing revealed SESN2 binding to and interacting with RPN2. RPN2 overexpression up-regulated MYOD, myogenin and myosin heavy chain 2, concurrently decreased p-GSK3β and increased nuclear β-catenin. Conversely, RPN2 knockdown yielded opposite results. Combining RPN2 knockdown with Leu rescued increased p-GSK3β and decreased nuclear β-catenin compared to Leu absence. Hematoxylin and eosin staining results showed that Leu addition accelerated mouse muscle damage repair, up-regulating Pax7, MYOD and RPN2 in the cytoplasm, and nuclear β-catenin, confirming that the role of Leu in muscle injury repair was consistent with the results for C2C12 cells.

CONCLUSION

Leu, bound with SESN2, up-regulated RPN2 expression, activated the GSK3β/β-catenin pathway, enhanced C2C12 differentiation and expedited skeletal muscle damage repair. © 2024 Society of Chemical Industry.

Role of Non-coding RNAs in the Response of Glioblastoma to Temozolomide

Chemotherapy and radiotherapy are widely used in clinical practice across the globe as cancer treatments. Intrinsic or acquired chemoresistance poses a significant problem for medical practitioners and researchers, causing tumor recurrence and metastasis. The most dangerous kind of malignant brain tumor is called glioblastoma multiforme (GBM) that often recurs following surgery. The most often used medication for treating GBM is temozolomide chemotherapy; however, most patients eventually become resistant. Researchers are studying preclinical models that accurately reflect human disease and can be used to speed up drug development to overcome chemoresistance in GBM. Non-coding RNAs (ncRNAs) have been shown to be substantial in regulating tumor development and facilitating treatment resistance in several cancers, such as GBM. In this work, we mentioned the mechanisms of how different ncRNAs (microRNAs, long non-coding RNAs, circular RNAs) can regulate temozolomide chemosensitivity in GBM. We also address the role of these ncRNAs encapsulated inside secreted exosomes.

Alternative Splicing in Glioblastoma and its Clinical Implication in Outcome Prediction

BACKGROUND AND OBJECTIVE

Alternative splicing (AS) offers an important mechanism to form protein polymorphism. A growing body of evidence indicates the correlation between splicing abnormality and carcinoma. Nevertheless, an overall analysis of AS signatures in glioblastoma (GBM) is absent and urgently needed.

METHODS

TCGA SpliceSea data was used to evaluate the AS profiles and further classified into different AS events. The survival analysis was based on these AS events, and AS-related genes were identified and performed with enrichment analysis. At last, the splicing factor-AS regulatory network was established in Cytoscape.

RESULTS

Eight hundred forty-two splicing events were confirmed as prognostic molecular events in GBM. Furthermore, the final prognostic signature constructed by seven AS events gave good result with an area under the curve (AUC) of receiver operating characteristic (ROC) curve up to 0.935 for five years, showing high potency in predicting patients' outcome. We built the splicing regulatory network to show the internal relationship of splicing events in GBM. PC4 and SFRS1 interacting protein 1 (PSIP1) and histone H4 acetylation may play a significant part in the prognosis induced by splicing events.

CONCLUSION

In our study, a high-efficiency prognostic prediction model was built for GBM patients based on AS events, which could become potential prognostic biomarkers for GBM. Meanwhile, PSIP1 may be a critical target for pharmaceutical treatment.

Identification and Prognostic Value of m6A-Related Genes in Glioblastoma

BACKGROUND

N6-methyladenosine (m6A) is one of the most common forms of mRNA modification, which is dynamically regulated by the m6A-related genes; however, its effect in glioblastoma (GBM) is still unknown.

OBJECTIVE

We sought to investigate the association between m6A-related genes (m6A-RGs) and GBM.

METHODS

Transcriptome data and the relevant clinical data were downloaded from The Cancer Genome Atlas and Gene Expression Omnibus databases. The m6A-RGs were identified from differently expressed genes, and COX and lasso regression models were applied to locate the prognosis-related genes.

RESULTS

We identified 15 out of 19 m6A-RGs differentially expressed between GBM and nontumor tissues. We identified two subgroups of GBM (clusters 1 and 2) by applying consensus clustering. Compared with the cluster 1 subgroup, the cluster 1 subgroup correlates with a poorer prognosis, and most of the 19 m6A-RGs are higher expressed in cluster 1. Through univariate Cox and lasso regression model, we identified three m6A-RGs, namely HNRNPC, ALKBH5, and FTO, which were used to construct a Cox regression risk model to predict the prognosis of GBM patients.

CONCLUSION

We identified a valuable m6A model for predicting the prognosis of GBM patients, which can provide useful epigenetic biomarkers.

Transcriptomic analysis identifies the neuropeptide cortistatin (CORT) as an inhibitor of temozolomide (TMZ) resistance by suppressing the NF-κB-MGMT signaling axis in human glioma

Glioma is a common tumor originating in the brain that has a high mortality rate. Temozolomide (TMZ) is the first-line treatment for high-grade gliomas. However, a large proportion of gliomas are resistant to TMZ, posing a great challenge to their treatment. In the study, the specific functions and mechanism(s) by which cortistatin (CORT) regulates TMZ resistance and glioma progression were evaluated. The decreased expression of CORT was detected in glioma tissues, and highly expressed CORT was associated with a better survival rate in patients with glioma. CORT overexpression notably decreased the capacity of glioma cells to proliferate and migrate in vitro and to form tumors in vivo. CORT overexpression also markedly suppressed the viability and enhanced the apoptosis of TMZ-resistant U251 cells by regulating MGMT, p21, and Puma expression. Importantly, CORT overexpression reduced the resistance of gliomas to TMZ in vivo. CORT expression was negatively correlated with MGMT expression in both glioma tissues and cells, and it was found that CORT inhibited NF-κB pathway activation in glioma cells, thereby inhibiting MGMT expression. In conclusion, CORT regulates glioma cell growth, migration, apoptosis, and TMZ resistance by weakening the activity of NF-κB/p65 and thereby regulating MGMT expression. The CORT/NF-κB/MGMT axis might be regarded as a molecular mechanism contributing to the resistance of glioma to TMZ. Our data also suggest that CORT regulates the viability and metastatic potential of glioma cells, independent of its effects on TMZ resistance, providing evidence of novel therapeutic targets for glioma that should be evaluated in further studies.

Classification of Glioblastoma Associated with Immune Checkpoints and Tumor Microenvironment based on Immunogenomic Profiling

BACKGROUND

Immune microenvironment is involved in tumor initiation and progression, and its effect on glioblastoma (GBM) is still unknown.

OBJECT

We sought to investigate the association between immune status and GBM.

METHODS

Transcriptome data and the relevant clinical data were downloaded from The Cancer Genome Atlas and Gene Expression Omnibus (GEO) databases, and we identified two immune subtypes based on 29 immune-associated gene sets.

RESULTS

Through single-sample gene set enrichment analysis (ssGSEA), we found that the high-immunity subtype had the most tumor-infiltrating immune cells and immune checkpoint molecules in GBM patients. Furthermore, we could more effectively identify immune signature pathways in GBM.

CONCLUSION

After validation with the GEO dataset, we conclude that the identified GBM high-immune subtypes may be amenable to the application of novel immune therapy for GBM.

Exploring signaling pathway crosstalk in glioma by mapping miRNA and WNT pathways: A review

Glioma is a significant healthcare burden; nevertheless, the particular genetic regulatory mechanism underpinning its onset and progression is still unknown. Recent research has focused in large part on trying to determine the underlying molecular pathways that contribute to the malignancy of this disease because of the difficulties in treating it. Many tumors have been linked to changes in the expression of microRNAs (miRNAs). miRNAs play a critical role in cancer development by controlling a wide variety of targets and signaling cascades. A rising body of evidence emphasizes WNT pathway dysregulation in glioma, despite the fact that it is dysregulated in many malignancies. Here, we give a detailed analysis of the roles played by miRNAs in the WNT pathway by glioma. We also demonstrate how the WNT pathway cooperates with miRNAs to control a variety of functions, including cell proliferation, invasion, migration, and epithelial-mesenchymal transition.

Dishevelled-associated antagonist of β-catenin homolog 3 (DACT3) suppresses glioma progression though Notch1 signaling pathway in β-catenin-dependent manner

The disheveled-associated antagonist of β-catenin homolog 3 (DACT3) has been recognized as a tumor suppressor in various cancers. However, the function of DACT3 on glioma malignant progression along with potential molecular mechanisms is poorly clarified. This research aimed to investigate how DACT3 contributes to suppressing the progression of glioma. In our investigation, a pronounced decrease in DACT3 expression was observed in glioma tissues. Through the overexpression of DACT3, we noted a significant suppression in the proliferation, invasion, and migration of glioma cells, while concurrently observing an increase in cell adhesion. Our exploration into the molecular mechanisms revealed that DACT3 executes its tumor-suppressive role by impeding the expression of notch 1 intracellular domain (NICD) and translocating into the nucleus by downregulating the expression of β-catenin. Consequently, this process leads to the suppression of Notch1 signaling. To summarize, our findings reveal the function of DACT3 to inhibit glioma progression via the Notch1 signaling pathway in β-catenin dependent manner. This study stands as the pioneer in examining the role of DACT3 in glioma progression and comprehensively elucidating its molecular mechanisms in glioma development. Therefore, our results suggest that DACT3 holds promise as both a prognostic factor and a potential biomarker for guiding treatment strategies in glioma patients (Graphical Abstract).

Novel Immune-Related LncRNA Pairs are Associated with Immunol Infiltration and Survival Status in Glioblastoma

Background

Immune-related lncRNA is involved in tumor initiation and progression, while its effect in glioblastoma (GBM) is still unknown.

Objective

We sought to investigate the association between immune-related lncRNA (ir-lncRNA) and GBM.

Methods

Transcriptomic and clinical data were obtained from the TCGA dataset, and we found 2008 ir-lncRNA differentially expressed between GBM and adjacent brain tissues.

Results

Appling the univariate Cox and Lasso regression model, we found 30 prognosis-related ir-lncRNA pairs to construct a Cox regression risk model to associate the outcome of GBM patients. Furthermore, with this risk model, we can identify the tumor immune infiltration status, the expression of immunosuppressive biomarkers, and chemical sensitivity in GBM patients.

Conclusions

We constructed an immunologic risk model with lncRNA to associate the survival outcome of GBM patients, which can provide useful biomarkers.

A comprehension of signaling pathways and drug resistance; an insight into the correlation between microRNAs and cancer

Despite the development of numerous therapies, cancer remains an incurable disease due to various factors, including drug resistance produced by cancer cells. MicroRNAs (miRNAs) regulate different target genes involved in biological and pathological processes, including cancer, through post-transcriptional mechanisms. The development of drug resistance in cancer treatment is a significant barrier because it decreases drug uptake, cellular transport, and changes in proteins involved in cell proliferation, survival, and apoptotic pathways. Numerous studies have found a connection between miRNAs and the development of drug resistance in cancer cells. This paper provides a broad overview of how miRNAs regulate signaling pathways and influence treatment resistance in different cancers.

Epigenetic regulation of temozolomide resistance in human cancers with an emphasis on brain tumors: Function of non-coding RNAs

Brain tumors, which are highly malignant, pose a significant threat to health and often result in substantial rates of mortality and morbidity worldwide. The brain cancer therapy has been challenging due to obstacles such as the BBB, which hinders effective delivery of therapeutic agents. Additionally, the emergence of drug resistance further complicates the management of brain tumors. TMZ is utilized in brain cancer removal, but resistance is a drawback. ncRNAs are implicated in various diseases, and their involvement in the cancer is particularly noteworthy. The focus of the current manuscript is to explore the involvement of ncRNAs in controlling drug resistance, specifically in the context of resistance to the chemotherapy drug TMZ. The review emphasizes the function of ncRNAs, particularly miRNAs, in modulating the growth and invasion of brain tumors, which significantly influences their response to TMZ treatment. Through their interactions with various molecular pathways, miRNAs are modulators of TMZ response. Similarly, lncRNAs also associate with molecular pathways and miRNAs, affecting the efficacy of TMZ chemotherapy. Given their functional properties, lncRNAs can either induce or suppress TMZ resistance in brain tumors. Furthermore, circRNAs, which are cancer controllers, regulate miRNAs by acting as sponges, thereby impacting the response to TMZ chemotherapy. The review explores the correlation between ncRNAs and TMZ chemotherapy, shedding light on the underlying molecular pathways involved in this process.

A Comprehensive Review of miRNAs and Their Epigenetic Effects in Glioblastoma

Glioblastoma is the most aggressive form of brain tumor originating from glial cells with a maximum life expectancy of 14.6 months. Despite the establishment of multiple promising therapies, the clinical outcome of glioblastoma patients is abysmal. Drug resistance has been identified as a major factor contributing to the failure of current multimodal therapy. Epigenetic modification, especially DNA methylation has been identified as a major regulatory mechanism behind glioblastoma progression. In addition, miRNAs, a class of non-coding RNA, have been found to play a role in the regulation as well as in the diagnosis of glioblastoma. The relationship between epigenetics, drug resistance, and glioblastoma progression has been clearly demonstrated. MGMT hypermethylation, leading to a lack of MGMT expression, is associated with a cytotoxic effect of TMZ in GBM, while resistance to TMZ frequently appears in MGMT non-methylated GBM. In this review, we will elaborate on known miRNAs linked to glioblastoma; their distinctive oncogenic or tumor suppressor roles; and how epigenetic modification of miRNAs, particularly via methylation, leads to their upregulation or downregulation in glioblastoma. Moreover, we will try to identify those miRNAs that might be potential regulators of MGMT expression and their role as predictors of tumor response to temozolomide treatment. Although we do not impact clinical data and survival, we open possible experimental approaches to treat GBM, although they should be further validated with clinically oriented studies.

UBE2T Promotes Temozolomide Resistance of Glioblastoma Through Regulating the Wnt/β-Catenin Signaling Pathway

Purpose

Patients with glioblastoma (GBM) have poor prognosis and limited therapeutic options, largely because of chemoresistance to temozolomide (TMZ) treatment. Ubiquitin conjugating enzyme E2 T (UBE2T) plays a key role in regulating the malignancy of various tumors, including GBM; however, its role in TMZ resistance of GBM has not been elucidated. The purpose of this study was to clarify the role of UBE2T in mediating TMZ resistance and investigate the specific underlying mechanism.

Methods

Western blotting was used to detect the protein levels of UBE2T and Wnt/β-catenin-related factors. CCK-8, flow cytometry, and colony formation assays were used to examine the effect of UBE2T on TMZ resistance. Wnt/β-catenin signaling pathway activation was inhibited using XAV-939, and a xenograft mouse model was generated to clarify the function of TMZ in vivo.

Results

UBE2T knockdown sensitized GBM cells to TMZ treatment, whereas UBE2T overexpression promoted TMZ resistance. The specific UBE2T inhibitor, M435-1279, increased the sensitivity of GBM cells to TMZ. Mechanistically, our results demonstrated that UBE2T induces β-catenin nuclear translocation and increases the protein levels of downstream molecules, including survivin and c-Myc. Inhibition of Wnt/β-catenin signaling using XAV-939 blocked TMZ resistance due to UBE2T overexpression in GBM cells. In addition, UBE2T was shown to facilitate TMZ resistance by inducing Wnt/β-catenin signaling pathway activation in a mouse xenograft model. Combined treatment with TMZ and UBE2T inhibitor achieved superior tumor growth suppression relative to TMZ treatment alone.

Conclusion

Our data reveal a novel role of UBE2T in mediating TMZ resistance of GBM cells via regulating Wnt/β-catenin signaling. These findings indicate that targeting UBE2T has promising potential to overcome TMZ resistance of GBM.

RPN2 in cancer: An overview

Oncogenes together with tumor suppresser genes are confirmed to regulate tumor phenotype in human cancers. RPN2, widely verified as an oncogene, encodes a protein that is part of an N-oligosaccharyl transferase, and is observed to be aberrantly expressed in human malignancies. Accumulating evidence unveils the vital functions of RPN2, contributing to tumorigenicity, metastasis, progression, and multi-drug resistance. Furthermore, previous studies partly indicated that RPN2 was involved in tumor progression via contributing to N-glycosylation and regulating multiple signaling pathways. In addition, RPN2 was also confirmed as a downstream target involved in tumor progression. Moreover, with demonstrated prognosis value and therapeutic target, RPN2 was also determined as a promising biomarker for forecasting patients' prognostic and therapy efficacy. In the present review, we aimed to summarize the present studies of RPN2 in cancer, and enhance the understanding of RPN2's extensive functions and clinical significances.

Single-Cell Sequencing Reveals Necroptosis-Related Prognostic Genes of Glioblastoma

Background

Glioblastoma (GBM) is one of the most malignant forms of brain cancer, with the extremely lower survival rate. Necroptosis (NCPS) is also one of the most wide types of cell death, and its clinical importance in GBM is not clear.

Methods

We first identified necroptotic genes in GBM by single-cell RNA sequencing analysis of our surgical samples and weighted coexpression network analysis (WGNCA) from TCGA GBM data. The cox regression model with least absolute shrinkage and selection operator (LASSO) was used to construct the risk model. Then, KM plot and reactive operation curve (ROC) analysis were used to assess the prediction ability of the model. At last, the infiltrated immune cells and gene mutation profiling were investigated between the high- and low-NCPS groups as well.

Result

The risk model including ten necroptosis-related genes was identified as an independent risk factor for the outcome. In addition, we found that the risk model is correlated with the infiltrated immune cells and tumor mutation burden in GBM. NDUFB2 is identified to be a risk gene in GBM with bioinformatical analysis and in vitro experiment validation.

Conclusion

This risk model of necroptosis-related genes might provide clinical evidence for GBM interventions.

Natural Steroidal Lactone Induces G1/S Phase Cell Cycle Arrest and Intrinsic Apoptotic Pathway by Up-Regulating Tumor Suppressive miRNA in Triple-Negative Breast Cancer Cells

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with minimal treatment options. In the present work, Withaferin A (WA), a natural steroidal lactone found in Withania somnifera (Solanaceae), was studied to deduce the miRNA expression modulation mediated anticancer mode of action in TNBC cells. Small RNA next generation sequencing (NGS) of WA (2 µM) and vehicle (0.1% DMSO)-treated MDA-MB-231 cells revealed a total of 413 differentially expressed miRNAs (DEMs) and demonstrated that WA potentially up-regulates the miR-181c-5p, miR-15a-5p, miR-500b-5p, miR-191-3p, and miR-34a-5p and down-regulates miR-1275, miR-326, miR-1908-5p, and miR-3940-3p among total DEMs. The NGS and qRT-PCR expression analysis revealed a significantly higher expression of miR-181c-5p among the top 10 DEMs. Predicted target genes of the DEMs showed enrichment in cancer-associated gene ontology terms and KEGG signaling pathways. Transient up-expression of mir-181c-5p showed a time-dependent decrease in MDA-MB-231 and MDA-MB-453 cell viability. Co-treatment of miR-181c-5p mimic and WA (at varying concentration) down-regulated cell cycle progression markers (CDK4 and Cyclin D1) at mRNA and protein levels. The treatment induced apoptosis in MDA-MB-231 cells by modulating the expression/activity of Bax, Bcl2, Caspase 3, Caspase 8, Caspase 3/7, and PARP at mRNA and protein levels. Confocal microscopy and Annexin PI assays revealed apoptotic induction in miRNA- and steroidal-lactone-treated MDA-MB-231 cells. Results indicate that the Withaferin A and miRNA mimic co-treatment strategy may be utilized as a newer therapeutic strategy to treat triple-negative breast cancer.

circTOP2A functions as a ceRNA to promote glioma progression by upregulating RPN2

Competing endogenous RNA (ceRNA)-mediated signaling pathway dysregulation provides great insight into comprehensively understanding the molecular mechanism and combined targeted therapy for glioblastoma. circRNA is characterized by high stability, tissue/developmental stage-specific expression and abundance in brain and plays significant roles in the initiation and progression of cancer. Our previous published data have demonstrated that RPN2 was significantly upregulated in glioma and promoted tumor progression via the activation of the Wnt/β-catenin pathway. Furthermore, we proved that miR-422a regulated the Wnt/β-catenin signaling pathway by directly targeting RPN2. In this study, based on the glioblastoma microarray profiles, we identified the upstream circTOP2A, which completely bound to miR-422a and was co-expressed with the RPN2. circTOP2A was significantly overexpressed in glioma and conferred a poor prognosis. circTOP2A could regulate RPN2 expression by sponging miR-422a, verified by western blot, dual-luciferase reporter gene assay, and RNA pull-down assay. Functional assays including CCK8, transwell and FITC-annexin V were performed to explore the RPN2-mediated role of the circTOP2A effect on the glioma malignant phenotype. Additionally, TOP/FOP and immunofluorescence analysis were used to confirm that sh-circTOP2A could suppress the Wnt/β-catenin pathway partly through RPN2. Finally, a tumor xenograft model was applied to validate the biological function of circTOP2A in vivo. Taken together, our findings reveal the critical role of circTOP2A in promoting glioma proliferation and invasion via a ceRNA mechanism and provide an exploitable biomarker and therapeutic target for glioma patients.

miR-1297 sensitizes glioma cells to temozolomide (TMZ) treatment through targeting adrenomedullin (ADM)

BACKGROUND

Gliomas account for about 80% of all malignant brain and other central nervous system (CNS) tumors. Temozolomide (TMZ) resistance represents a major treatment hurdle. Adrenomedullin (ADM) has been reported to induce glioblastoma cell growth.

METHODS

Cell viability was measured using the CCK-8 assay. The apoptosis analysis was performed using the Annexin V-FITC Apoptosis Detection Kit. The mitochondrial membrane potential was determined by JC-1 staining. A nude mouse tumor assay was used to detect tumor formation. Hematoxylin and eosin (H&E) and immunohistochemical (IHC) staining were performed in tissue sections. Activation of Akt and Erk and expression of apoptosis-related proteins were determined by immunoblotting.

RESULTS

ADM expression has been found upregulated in TMZ -resistant glioma samples based on bioinformatics and experimental analyses. Knocking down ADM in glioma cells enhanced the suppressive effects of TMZ on glioma cell viability, promotive effects on cell apoptosis, and inhibitory effects on mitochondrial membrane potential. Moreover, ADM knockdown also enhanced TMZ effects on Bax/Bcl-2, Akt phosphorylation, and Erk1/2 phosphorylation. Bioinformatics and experimental investigation indicated that miR-1297 directly targeted ADM and inhibited ADM expression. miR-1297 overexpression exerted similar effects to ADM knockdown on TMZ-treated glioma cells. More importantly, under TMZ treatment, inhibition of miR-1297 attenuated TMZ treatment on glioma cells; ADM knockdown partially attenuated the effects of miR-1297 inhibition on TMZ-treated glioma cells.

CONCLUSIONS

miR-1297 sensitizes glioma cells to TMZ treatment through targeting ADM. The Bax/Bcl-2, Akt, and Erk1/2 signaling pathways, as well as mitochondrial functions might be involved.

Peroxidase is a novel potential marker in glioblastoma through bioinformatics method and experimental validation

Peroxidase (PXDN), a specific extracellular matrix (ECM)-associated protein, has been determined as a tumor indicator and therapeutic target in various tumors. However, the effects of PXDN in prognostic performance and clinical implications in glioblastoma multiforme (GBM) remains unknown. Here, we assessed PXDN expression pattern and its performance on prognosis among GBM cases from TCGA and CGGA databases. PXDN was up-regulated within GBM samples in comparison with normal control. High PXDN expression was a dismal prognostic indicator in GBM. Single cell RNA analysis was conducted to detect the cell localization of PXDN. We also set up a PPI network to explore the interacting protein associated with PXDN, including TSKU, COL4A1 and COL5A1. Consistently, functional enrichment analysis revealed that several cancer hallmarks were enriched in the GBM cases with high PXDN expression, such as epithelial-mesenchymal transition (EMT), fatty acid metabolism, glycolysis, hypoxia, inflammatory response, and Wnt/beta-catenin signaling pathway. Next, this study analyzed the association of PXDN expression and immunocyte infiltration. PXDN expression was in direct proportion to the infiltrating degrees of NK cells resting, T cells regulatory, M0 macrophage, monocytes and eosinophils. The roles of PXDN on immunity were further estimated by PXDN-associated immunomodulators. In addition, four prognosis-related lncRNAs co-expressed with PXDN were identified. Finally, we observed that PXDN depletion inhibits GBM cell proliferation and migration by in vitro experiments. Our data suggested that PXDN has the potential to be a powerful prognostic biomarker, which might offer a basis for developing therapeutic targets for GBM.

RP11-552D4.1: a novel m6a-related LncRNA associated with immune status in glioblastoma

Glioblastoma (GBM) is the most malignant form of brain cancer in the world. Nevertheless, the survival rate of patients with GBM is extremely low. N6-methyladenosine (m6A) and long noncoding RNAs (lncRNAs) conduct important biological functions in patients’ survival status and the immunotherapeutic response. Here, m6A-related lncRNAs were identified by a co-expression method. Univariate and multivariate Cox regression together with LASSO were applied to establish the risk model. Kaplan-Meier and ROC analysis were applied to evaluate the prediction power of this risk model. Finally, the related immune profiling and chemical sensitivity targets were also investigated. The risk model holding three m6A-related lncRNAs was confirmed as an independent predictor for the prognosis. Furthermore, we found the risk model based on m6A-related lncRNAs is associated with the immune status, immunosuppressive biomarkers, and chemo-sensitivity in GBM patients. The RP11-552D4.1 is found to facilitate neuronal proliferation. This risk model consisted of m6A-related lncRNAs may be available for the clinical interventions in GBM patients.

Ribophorin II promotes the epithelial-mesenchymal transition and aerobic glycolysis of laryngeal squamous cell carcinoma via regulating reactive oxygen species-mediated Phosphatidylinositol-3-Kinase/Protein Kinase B activation

Ribophorin II (RPN2), a part of an N-oligosaccharyl transferase complex, plays vital roles in the development of multiple cancers. Nevertheless, its biological role in laryngeal squamous cell carcinoma (LSCC) remains unclear. The RPN2 expression levels in LSCC tissues and cell lines (AMC-HN-8 and TU212) were measured using real-time PCR, immunohistochemistry, or Western blot. The influences of RPN2 on the proliferation, migration, epithelial–mesenchymal transition, and aerobic glycolysis of LSCC cells were investigated after upregulation or downregulation of RPN2 in vitro and in vivo. Mechanically, we assessed the impact of RPN2 on the reactive oxygen species (ROS)/Phosphatidylinositol-3-Kinase (PI3K)/Protein Kinase B (Akt) signaling pathway. We found that compared with the control, RPN2 was highly expressed in LSCC tissues and cells. Overexpression of RPN2 elevated the proliferation, migration, glucose uptake, lactate production release, and levels of Vimentin, hexokinase-2 (HK-2), pyruvate dehydrogenase kinase 1 (PDK1), lactate dehydrogenase A (LDHA), and ROS, but inhibited E-cadherin expression in AMC-HN-8 cells. Knockdown of RPN2 in TU212 cells showed opposite effects on the above indexes. Meanwhile, RPN2 upregulation increased the levels of p-PI3K/PI3K and p-Akt/Akt, which were attenuated by N-acetyl-L-cysteine (NAC), an ROS inhibitor. Both NAC and PI3K inhibitor LY294002 could reverse the effects of RPN2 overexpression on the malignant phenotypes of LSCC cells. In xenografted mice, silencing RPN2 expression reduced tumor growth, ROS production, and levels of Ki-67, Vimentin, LDHA, and p-Akt/Akt, but enhanced E-cadherin expression. In conclusion, our data suggested that RPN2 promoted the proliferation, migration, EMT, and glycolysis of LSCC via modulating ROS-mediated PI3K/Akt activation.

CN-3 increases TMZ sensitivity and induces ROS-dependent apoptosis and autophagy in TMZ-resistance glioblastoma

Many glioma patients develop resistance to temozolomide (TMZ) treatment, resulting in reduced efficacy and survival rates. TMZ-resistant cell lines SHG44R and U87R, which highly express O₆ -methylguanine DNA methyltransferase (MGMT) and P-gp, were established. CN-3, a new asterosaponin, showed cytotoxic effects on TMZ-resistant cells in a dose- and time-dependent manner via reactive oxygen species (ROS)-mediated apoptosis and autophagy. Transmission electron microscopy and monodansylcadaverine (MDC) staining showed turgidity of the mitochondria and autophagosomes in CN-3-treated SHG44R and U87R cells. The autophagy inhibitor 3-methyladenine was used to confirm the important role of autophagy in CN-3 cytotoxicity in TMZ-resistant cells. The ROS scavenger N-acetyl- l-cysteine (NAC) attenuated the levels of ROS induced by CN-3 and, therefore, rescued the CN-3 cytotoxic effect on the viability of SHG44R and U87R cells by Cell Counting Kit-8 assays and JuLI-Stage videos. MDC staining also confirmed that NAC rescued an autophagosome increase in CN-3-treated SHG44R and U87R cells. Western blotting revealed that CN-3 increased Bax, cleaved-caspase 3, cytochrome C, PARP-1, LC3-Ⅱ, and Beclin1, and decreased P-AKT, Bcl-2, and p62. Further rescue experiments revealed that CN-3 induced apoptosis and autophagy through ROS-mediated cytochrome C, cleaved-caspase 3, Bcl-2, P-AKT, PARP-1, and LC3-Ⅱ. In addition, CN-3 promoted SHG44R and U87R cells sensitive to TMZ by reducing the expression of P-gp, MGMT, and nuclear factor kappa B p65, and it had a synergistic cytotoxic effect with TMZ. Moreover, CN-3 disrupted the natural cycle arrest and inhibited the migration of SHG44R and U87R cells by promoting cyclin E1 and D1, and by decreasing P21, P27, N-cadherin, β-catenin, transforming growth factor beta 1, and Smad2.

Regulatory interplay between microRNAs and WNT pathway in glioma

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

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

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

The Role of Notch, Hedgehog, and Wnt Signaling Pathways in the Resistance of Tumors to Anticancer Therapies

Resistance to therapy is the major hurdle in the current cancer management. Cancer cells often rewire their cellular process to alternate mechanisms to resist the deleterious effect mounted by different therapeutic approaches. The major signaling pathways involved in the developmental process, such as Notch, Hedgehog, and Wnt, play a vital role in development, tumorigenesis, and also in the resistance to the various anticancer therapies. Understanding how cancer utilizes these developmental pathways in acquiring the resistance to the multi-therapeutic approach cancer can give rise to a new insight of the anti-therapy resistance mechanisms, which can be explored for the development of a novel therapeutic approach. We present a brief overview of Notch, Hedgehog, and Wnt signaling pathways in cancer and its role in providing resistance to various cancer treatment modalities such as chemotherapy, radiotherapy, molecular targeted therapy, and immunotherapy. Understanding the importance of these molecular networks will provide a rational basis for novel and safer combined anticancer therapeutic approaches for the improvement of cancer treatment by overcoming drug resistance.