CRB2 enhances malignancy of glioblastoma via activation of the NF-κB pathway.

Glioblastoma (GBM) is one of the most lethal types of primary brain tumors in adults with a median survival of less than 15 months. Although comprehensive clinical treatment strategies including surgical resection followed by radiotherapy and chemotherapy are widely applied, the prognosis for GBM patients remains dismal. The Nuclear Factor-κB (NF-κB) signaling pathway is a complex network linking extracellular stimuli to cell survival and proliferation, and aberrant activation of NF-κB signaling has been implicated in the propagation of a wide range of cancers. However, the underlying mechanism of NF-κB activation still requires further investigation. Here, we report that crumbs homolog 2 (CRB2) is markedly up-regulated in human GBM relative to non-tumor tissues or normal astrocytes. Clinically, enriched CRB2 could be observed in high grade glioma with IDH IDH wild-type and 1p19q co-deletion and implied poor outcome in GBM. Consistent with this, malignant characteristics of GBM cells including proliferation, migration, invasion and tumorigenesis were significantly suppressed by lentivirus knock-down of CRB2. Furthermore, exogenous overexpression of CRB2 enhanced the malignant biological signatures of GBM cells as well as therapy resistance to temozolomide (TMZ). To further investigate the molecular mechanisms responsible, bioinformatics analysis was performed using 3 public databases, with the result that CRB2 was found to correlate closely with tumor necrosis factor α (TNFα)-NF-κB signaling. Mechanistically, elevated CRB2 increased the phosphorylation of IκB-kinase α (IKKα), thus activating NF-κB via reduction of Ikß protein. Taken together, these data suggest that CRB2 might be a reliable prognostic biomarker and potential therapeutic target for GBM.

Retinol binding protein 1-dependent activation of NF- κB signaling enhances the malignancy of non-glioblastomatous diffuse gliomas.

Nonglioblastomatous diffuse glioma (non-GDG) is a heterogeneous neuroepithelial tumor that exhibits a varied survival range from 4 to 13 years based on the diverse subtypes. Recent studies demonstrated novel molecular markers can predict prognosis for non-GDG patients; however, these findings as well as pathological classification strategies show obvious limitations on malignant transition due to the heterogeneity among non-GDGs. Therefore, developing reliable prognostic biomarkers and therapeutic targets have become an urgent need for precisely distinguishing non-GDG subtypes, illuminating the underlying mechanism. Nuclear factor κß (NF-κB) has been proved to be a significant nuclear transcriptional regulator with specific DNA-binding sequences to participate in multiple pathophysiological processes. However, the underlying mechanism of NF-κB activation still needs to be further investigated. Herein, our results indicated retinol-binding protein 1 (RBP1) was significantly upregulated in the IDHWT and 1p19qNon co-del non-GDG subtypes and enriched RBP1 expression was markedly correlated with more severe outcomes. Additionally, malignant signatures of the non-GDG cells including proliferation, migration, invasion, and self-renewal were significantly suppressed by lentiviral knockdown of RBP1. To further explore the underlying molecular mechanism, bioinformatics analysis was performed using databases, and the results demonstrated RBP1 was strongly correlated with tumor necrosis factor α (TNFα)-NF-κB signaling. Moreover, exogenous silencing of RBP1 reduced phosphorylation of IkB-kinase α (IKKα) and thus decreased NF-κB expression via decreasing the degradation of the IκBα protein. Altogether, these data suggested RBP1-dependent activation of NF-κB signaling promoted malignancy of non-GDG, indicating that RBP1 could be a reliable prognostic biomarker and potential therapeutic target for non-GDG.

FABP5 enhances malignancies of lower-grade gliomas via canonical activation of NF-κB signaling.

Low-grade gliomas (LGGs) are grade III gliomas based on the WHO classification with significant genetic heterogeneity and clinical properties. Traditional histological classification of gliomas has been challenged by the improvement of molecular stratification; however, the reproducibility and diagnostic accuracy of LGGs classification still remain poor. Herein, we identified fatty acid binding protein 5 (FABP5) as one of the most enriched genes in malignant LGGs and elevated FABP5 revealed severe outcomes in LGGs. Functionally, lentiviral suppression of FABP5 reduced malignant characters including proliferation, cloning formation, immigration, invasion and TMZ resistance, contrarily, the malignancies of LGGs were enhanced by exogenous overexpression of FABP5. Mechanistically, epithelial-mesenchymal transition (EMT) was correlated to FABP5 expression in LGGs and tumour necrosis factor α (TNFα)-dependent NF-κB signalling was involved in this process. Furthermore, FABP5 induced phosphorylation of inhibitor of nuclear factor kappa-B kinase α (IKKα) thus activated nuclear factor kappa-B (NF-κB) signalling. Taken together, our study indicated that FABP5 enhances malignancies of LGGs through canonical activation of NF-κB signalling, which could be used as individualized prognostic biomarker and potential therapeutic target of LGGs.

WITHDRAWN: ESM1-dependent mesenchymal transition enhances radioresistance of glioblastoma via transcriptional regulation of NFκB.

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Apolipoprotein E polymorphism and the risk of intracranial aneurysms in a Chinese population.

BACKGROUND: The relationship between the apolipoprotein E (APOE) polymorphism and intracranial aneurysms has previously only been studied in Russia and Japan but not in Chinese populations. The purpose of this study was to investigate the association between APOE polymorphism and the risk of intracranial aneurysms in a Chinese population. METHODS: The study population consisted of 150 intracranial aneurysms patients and 150 matched control subjects. The APOE gene polymorphism was analyzed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: Patients with intracranial aneurysms had a significantly higher frequency of APOE E2/E2 genotype [odds ratio (OR) = 9.51, 95% confidence interval (CI) = 1.19, 76.04; P = 0.03] and APOE E2/E3 genotype (OR = 1.87, 95% CI = 1.03, 3.40; P = 0.04) than healthy controls. The APOE E4/E4 genotype frequencies (OR = 0.09, 95% CI = 0.01, 0.74; P = 0.03) in the intracranial aneurysms group were significantly lower than those in the controls group. When stratified by the site, shape, size and the Fisher Grade of intracranial aneurysms, no statistically significant result was observed. CONCLUSION: Our study suggested that APOE polymorphism might be associated with intracranial aneurysms in Chinese population. Additional studies are needed to confirm this finding.

Three polymorphisms of DNA repair gene XRCC1 and the risk of glioma: a case-control study in northwest China.

Three polymorphisms of X-ray repair cross-complementing groups 1 (XRCC1) Arg194Trp, Arg280His, and Arg399Gln may be associated with the individual susceptibility to glioma. The aim of this study was to investigate any association between three polymorphisms of the XRCC1 gene at codon 194, 280, and 399 and potential glioma risk. We conducted a hospital-based case-control study in northwest China. A total of 1,772 subjects, including 886 glioma patients and 886 healthy controls, were recruited in this study. The peripheral blood samples were extracted. Polymerase chain reaction-restriction fragment length polymorphism method was used to test genotypes. Glioma patients had a significantly higher frequency of XRCC1 194 TT (odds ratio [OR] = 1.76, 95 % confidence interval [CI] = 1.14, 2.72; P = 0.01) and XRCC1 399 AA genotype (OR = 1.62, 95 % CI = 1.09, 2.40; P = 0.02) than controls. When stratified by the grade of glioma, patients with WHO IV glioma had a significantly higher frequency of XRCC1 194 TT (OR = 1.60, 95 % CI = 1.02, 2.51; P = 0.04) and XRCC1 399 AA genotype (OR = 1.59, 95 % CI = 1.04, 2.42; P = 0.03). When stratified by the histology of glioma, there was no significant difference in the distribution of each genotype. This study suggested that XRCC1 Arg194Trp and Arg399Gln polymorphisms were associated with the risk of glioma.

A novel reference coordinate system to locate the inferomedial point of the transverse-sigmoid sinus junction.

BACKGROUND: A coordinate system was previously developed to identify landmarks on the skull surface to help locate the transverse-sigmoid sinus junction in order to reduce surgical morbidity in retrosigmoid craniotomy; however, in practice we found that this system has important flaws. OBJECTIVE: To develop and evaluate a novel reference coordinate system to precisely locate the inferomedial point of the transverse-sigmoid sinus junction (IMTS) and evaluate the effect of gender and skull side (left or right). METHODS: Forty-two adult skulls (84 sides) were obtained for analyses. The X-axis was defined by point A (where the upper edge of the zygomatic arch joins with the frontal process of the zygomatic bone) and point B (where the upper edge of the zygomatic arch blends posterosuperiorly into the supramastoid crest). The Y-axis was defined by the line perpendicular to the X-axis and extending across the tip of the mastoid. The x and y coordinates of IMTS (IMTS-x and IMTS-y) were measured in this coordinate system. RESULTS: There were 20 male skulls and 22 female skulls. The mean IMTS-x measurements were significantly higher on the right side compared with the left side in both males and females. For the left skull side, the mean IMTS-y measurements were significantly lower in females compared with males. CONCLUSION: This novel reference coordinate system may be a reliable and practical method for identifying the IMTS during retrosigmoid craniotomy. There are significant differences in location of the axes with regard to gender and skull side.

Safety and efficacy of magnesium-rich artificial cerebrospinal fluid for subarachnoid hemorrhage.

Objectives: This study aimed to investigate the efficacy of using a newly formulated magnesium-rich artificial cerebrospinal fluid (MACSF) as an alternative to normal saline (NS) for intraoperative irrigation during aneurysm clipping in improving the prognosis of patients with Aneurysmal subarachnoid hemorrhage (aSAH). Methods: Patients with aSAH who underwent intraoperative irrigation with MACSF or NS during the clipping in the First Affiliated Hospital of Xi 'an Jiaotong University from March 2019 to March 2022 were selected as MACSF group and NS group, respectively. The primary prognostic indicators were the incidence of favorable outcomes (mRS 0-2). The secondary outcome measures included cerebral vasospasm (CVS), mortality, total hospital stay, and intensive care unit (ICU) stay. Safety was evaluated based on the occurrence rates of hypermagnesemia, meningitis, and hydrocephalus. Results: Overall, 34 and 37 patients were enrolled in the MACSF and NS groups, respectively. At 90 days after aSAH onset, the proportion of favorable prognosis in the MACSF group was significantly higher than that in the NS group (p = 0.035). The incidence of CVS within 14 days after surgery was significantly lower in the MACSF group than that in the NS group (p = 0.026). The mortality rate in the MACSF group was significantly lower than in the NS group (p = 0.048). The median lengths of hospital stay (p = 0.008) and ICU stay (p = 0.018) were significantly shorter in the MACSF group than in the NS group. No significant differences were observed in safety measures. Conclusion: Using MACSF as an irrigation fluid for aneurysm clipping can significantly improve the 90-day prognosis of patients with aSAH, which may be related to the reduced incidence of CVS. Clinical trial registration: https://www.clinicaltrials.gov, identifier NCT04358445.

Development of prognostic indicator based on NAD+ metabolism related genes in glioma.

Background: Studies have shown that Nicotinamide adenine dinucleotide (NAD+) metabolism can promote the occurrence and development of glioma. However, the specific effects and mechanisms of NAD+ metabolism in glioma are unclear and there were no systematic researches about NAD+ metabolism related genes to predict the survival of patients with glioma. Methods: The research was performed based on expression data of glioma cases in the Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA) databases. Firstly, TCGA-glioma cases were classified into different subtypes based on 49 NAD+ metabolism-related genes (NMRGs) by consensus clustering. NAD+ metabolism-related differentially expressed genes (NMR-DEGs) were gotten by intersecting the 49 NMRGs and differentially expressed genes (DEGs) between normal and glioma samples. Then a risk model was built by Cox analysis and the least shrinkage and selection operator (LASSO) regression analysis. The validity of the model was verified by survival curves and receiver operating characteristic (ROC) curves. In addition, independent prognostic analysis of the risk model was performed by Cox analysis. Then, we also identified different immune cells, HLA family genes and immune checkpoints between high and low risk groups. Finally, the functions of model genes at single-cell level were also explored. Results: Consensus clustering classified glioma patients into two subtypes, and the overall survival (OS) of the two subtypes differed. A total of 11 NAD+ metabolism-related differentially expressed genes (NMR-DEGs) were screened by overlapping 5,995 differentially expressed genes (DEGs) and 49 NAD+ metabolism-related genes (NMRGs). Next, four model genes, PARP9, BST1, NMNAT2, and CD38, were obtained by Cox regression and least absolute shrinkage and selection operator (Lasso) regression analyses and to construct a risk model. The OS of high-risk group was lower. And the area under curves (AUCs) of Receiver operating characteristic (ROC) curves were >0.7 at 1, 3, and 5 years. Cox analysis showed that age, grade G3, grade G4, IDH status, ATRX status, BCR status, and risk Scores were reliable independent prognostic factors. In addition, three different immune cells, Mast cells activated, NK cells activated and B cells naive, 24 different HLA family genes, such as HLA-DPA1 and HLA-H, and 8 different immune checkpoints, such as ICOS, LAG3, and CD274, were found between the high and low risk groups. The model genes were significantly relevant with proliferation, cell differentiation, and apoptosis. Conclusion: The four genes, PARP9, BST1, NMNAT2, and CD38, might be important molecular biomarkers and therapeutic targets for glioma patients.

NEK2 enhances malignancies of glioblastoma via NIK/NF-κB pathway.

Glioblastoma (GBM) is one of the most lethal primary brain tumor with a poor median survival less than 15 months. Despite the development of the clinical strategies over the decades, the outcomes for GBM patients remain dismal due to the strong proliferation and invasion ability and the acquired resistance to radiotherapy and chemotherapy. Therefore, developing new biomarkers and therapeutic strategies targeting GBM is in urgent need. In this study, gene expression datasets and relevant clinical information were extracted from public cancers/glioma datasets, including TCGA, GRAVENDEEL, REMBRANDT, and GILL datasets. Differentially expressed genes were analyzed and NEK2 was picked as a candidate gene for subsequent validation. Human tissue samples and corresponding data were collected from our center and detected by immunohistochemistry analysis. Molecular biological assays and in vivo xenograft transplantation were performed to confirm the bioinformatic findings. High-throughput RNA sequencing, followed by KEGG analysis, GSEA analysis and GO analysis were conducted to identify potential signaling pathways related to NEK2 expression. Subsequent mechanism assays were used to verify the relationship between NEK2 and NF-κB signaling. Overall, we identified that NEK2 is significantly upregulated in GBM and the higher expression of NEK2 exhibited a poorer prognosis. Functionally, NEK2 knockdown attenuated cell proliferation, migration, invasion, and tumorigenesis of GBM while NEK2 overexpression promoted the GBM progression. Furthermore, High-throughput RNA sequencing and bioinformatics analysis indicated that NEK2 was positively related to the NF-κB signaling pathway in GBM. Mechanically, NEK2 activated the noncanonical NF-κB signaling pathway by phosphorylating NIK and increasing the activity and stability of NIK. In conclusion, NEK2 promoted the progression of GBM through activation of noncanonical NF-κB signaling, indicating that NEK2- NF-κB axis could be a potential drug target for GBM.

A Novel Multi-Omics Analysis Model for Diagnosis and Survival Prediction of Lower-Grade Glioma Patients.

Background: Lower-grade gliomas (LGGs) are characterized by remarkable genetic heterogeneity and different clinical outcomes. Classification of LGGs is improved by the development of molecular stratification markers including IDH mutation and 1p/19q chromosomal integrity, which are used as a hallmark of survival and therapy sensitivity of LGG patients. However, the reproducibility and sensitivity of the current classification remain ambiguous. This study aimed to construct more accurate risk-stratification approaches. Methods: According to bioinformatics, the sequencing profiles of methylation and transcription and imaging data derived from LGG patients were analyzed and developed predictable risk score and radiomics score. Moreover, the performance of predictable models was further validated. Results: In this study, we determined a cluster of 6 genes that were correlated with IDH mutation/1p19q co-deletion status. Risk score model was calculated based on 6 genes and showed gratifying sensitivity and specificity for survival prediction and therapy response of LGG patients. Furthermore, a radiomics risk score model was established to noninvasively assist judgment of risk score in pre-surgery. Taken together, a predictable nomogram that combined transcriptional signatures and clinical characteristics was established and validated to be preferable to the histopathological classification. Our novel multi-omics nomograms showed a satisfying performance. To establish a user-friendly application, the nomogram was further developed into a web-based platform: https://drw576223193.shinyapps.io/Nomo/, which could be used as a supporting method in addition to the current histopathological-based classification of gliomas. Conclusions: Our novel multi-omics nomograms showed the satisfying performance of LGG patients and assisted clinicians to draw up individualized clinical management.

Loss of PLK2 induces acquired resistance to temozolomide in GBM via activation of notch signaling.

BACKGROUND: Glioblastoma (GBM) is a lethal type of primary brain tumor with a median survival less than 15 months. Despite the recent improvements of comprehensive strategies, the outcomes for GBM patients remain dismal. Accumulating evidence indicates that rapid acquired chemoresistance is the major cause of GBM recurrence thus leads to worse clinical outcomes. Therefore, developing novel biomarkers and therapeutic targets for chemoresistant GBM is crucial for long-term cures. METHODS: Transcriptomic profiles of glioblastoma were downloaded from gene expression omnibus (GEO) and TCGA database. Differentially expressed genes were analyzed and candidate gene PLK2 was selected for subsequent validation. Clinical samples and corresponding data were collected from our center and measured using immunohistochemistry analysis. Lentiviral transduction and in vivo xenograft transplantation were used to validate the bioinformatic findings. GSEA analyses were conducted to identify potential signaling pathways related to PLK2 expression and further confirmed by in vitro mechanistic assays. RESULTS: In this study, we identified PLK2 as an extremely suppressed kinase-encoding gene in GBM samples, particularly in therapy resistant GBM. Additionally, reduced PLK2 expression implied poor prognosis and TMZ resistance in GBM patients. Functionally, up-regulated PLK2 attenuated cell proliferation, migration, invasion, and tumorigenesis of GBM cells. Besides, exogenous overexpression of PLK2 reduced acquired TMZ resistance of GBM cells. Furthermore, bioinformatics analysis indicated that PLK2 was negatively correlated with Notch signaling pathway in GBM. Mechanically, loss of PLK2 activated Notch pathway through negative transcriptional regulation of HES1 and degradation of Notch1. CONCLUSION: Loss of PLK2 enhances aggressive biological behavior of GBM through activation of Notch signaling, indicating that PLK2 could be a prognostic biomarker and potential therapeutic target for chemoresistant GBM.

Elevation of CXCL1 indicates poor prognosis and radioresistance by inducing mesenchymal transition in glioblastoma.

INTRODUCTION: Glioblastoma (GBM) is identified as a lethal malignant tumor derived from the nervous system. Despite the standard clinical strategy including maximum surgical resection, temozolomide (TMZ) chemotherapy, and radiotherapy, the median survival of GBM patients remains <15 months. Accumulating evidence indicates that rapid-acquired radioresistance is one of the most common reasons for GBM recurrence. Therefore, developing novel therapeutic targets for radioresistant GBM could yield long-term cures. AIMS: To investigate the functional role of CXCL1 in the acquired radioresistance and identify the molecular pathway correlated to CXCL1. RESULTS: In this study, we identified that CXCL1 is highly expressed in GBM and the elevation of CXCL1 is involved in radioresistance and poor prognosis in GBM patients. Additionally, silencing CXCL1 attenuated the proliferation and radioresistance of GBM cells. Furthermore, we demonstrated that CXCL1-overexpression induced radioresistance through mesenchymal transition of GBM via the activation of nuclear factor-kappa B (NF-κB) signaling. CONCLUSION: CXCL1 was highly enriched in GBM and positively correlated with poor prognosis in GBM patients. Additionally, elevated CXCL1 induced radioresistance in GBM through regulation of NF-κB signaling by promoting mesenchymal transition in GBM.

Combined elevation of TRIB2 and MAP3K1 indicates poor prognosis and chemoresistance to temozolomide in glioblastoma.

INTRODUCTION: Glioblastoma (GBM) is the most lethal primary malignant brain tumor in adults with poor survival due to acquired therapeutic resistance and rapid recurrence. Currently, the standard clinical strategy for glioma includes maximum surgical resection, radiotherapy, and temozolomide (TMZ) chemotherapy; however, the median survival of patients with GBM remains poor despite these comprehensive therapies. Therefore, the identification of new prognostic biomarkers is urgently needed to evaluate the malignancy and long-term outcome of glioma. AIMS: To further investigate prognostic biomarkers and potential therapeutic targets for GBM. RESULTS: In this study, we identified tribbles pseudokinase 2 (TRIB2) as one of the genes that is most correlated with pathological classification, radioresistance, and TMZ resistance in glioma. Additionally, the expression of mitogen-activated protein kinase kinase kinase 1 (MAP3K1) showed a strong correlation with TRIB2. Moreover, a combined increase in TRIB2 and MAP3K1 was observed in GBM and indicated a poor prognosis of patients with glioma. Finally, enriched TRIB2 expression and MAP3K1 expression were shown to be associated with resistance to TMZ and radiotherapy. CONCLUSION: Combined elevation of TRIB2 and MAP3K1 could be novel prognostic biomarkers and potential therapeutic targets to evaluate the malignancy and long-term outcomes of GBM.

Retraction: Receptor tyrosine kinase AXL is correlated with poor prognosis and induces temozolomide resistance in glioblastoma.

Retraction: Receptor tyrosine kinase AXL is correlated with poor prognosis and induces temozolomide resistance in glioblastoma, CNS Neuroscience & Therapeutics 2019, (https://doi.org/10.1111/cns.13227). The above article published online on 02 October 2019 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors, the journal Editor in Chief Jun Chen, and John Wiley & Sons Ltd. The retraction has been agreed due to unreliable data and consequently its misleading results and conclusions.

Inflammatory biomarkers in prognostic analysis for patients with glioma and the establishment of a nomogram.

Being biomarkers that reflect host nutritional and immune status, prognostic nutritional index (PNI) and neutrophil/lymphocyte ratio (NLR) have been identified to be independent prognostic factors in various malignancies. The aim of the present study was to determine the predictive value of these parameters for the prognosis of patients with glioma. Hematological and clinicopathological data were retrospectively analyzed from 128 patients with glioma who underwent brain tumor resection between January 2008 and December 2012. Receiver operating characteristic (ROC) analysis was used to determine the optimal cut-offs for PNI and NLR. Kaplan-Meier survival analysis, and univariate and multivariate analyses based on Cox proportional hazards regression model were used to determine whether NLR and PNI were associated with the prognosis of patients with glioma. R software was used to develop nomograms with all the independent prognostic factors included. Kaplan-Meier analysis followed by log-rank tests indicated that NLR ≥2.8 and PNI <45 were significantly associated with decreased overall survival time. The subsequent multivariate analysis indicated that age ≥50 years [hazard ratio (HR), 2.328; 95% confidence interval (CI), 1.386-3.908; P<0.001], high-grade glioma (HR, 3.088; 95% CI, 1.893-5.037; P<0.001), gross total resection (HR, 0.606; 95% CI, 0.380-0.965; P=0.035) and NLR ≥2.8 (HR, 2.037; 95% CI, 1.264-3.281; P=0.003) were independent prognostic factors. The results of the present study indicated that high NLR was an independent risk factor for overall survival rates in patients with glioma, which indicated its value in improving the current prognostic model.

Combined elevation of AURKB and UBE2C predicts severe outcomes and therapy resistance in glioma.

OBJECTIVES: Aurora kinase B (AURKB) and Ubiquitin conjugating enzyme E2C (UBE2C) are involved in tumorigenesis of gliomas and other malignancies as well, but their clinicopathologic significance in gliomas is unknown and the prognostic value of combined expression of AURKB and UBE2C has not been explored. In this study, we investigate the correlation between glioma prognosis and combined expressions of AURKB and UBE2C thus to identify novel therapeutic targets and prognostic biomarkers for glioma patients. METHODS: AURKB was identified as one of the key candidate kinase-encoding genes in three different databases by using kinome-wide bioinformatic analysis. Afterwards, UBE2C was chosen as the most closely relevant genes to AURKB according to Spearman correlation test. Then the expressions of AURKB and UBE2C at either transcriptome or protein levels were measured by quantitative Real-time PCR (qRT-PCR) or immunohistochemistry (IHC), respectively. Additionally, Kaplan-Meier analyses were conducted using data from TCGA, Rembrandt and our clinical center to investigate the clinical significance of AURKB and UBE2C. Furthermore, receiver operating characteristic (ROC) analysis was performed to evaluate the sensitivity and specificity of AURKB and UBE2C in predicting the outcomes of glioma patients. Moreover, survival data of patients who underwent post-surgical chemo/radio treatment were extracted and the Kaplan-Meier analyses were performed to investigate the correlation between treatment resistance and combined expressions of AURKB and UBE2C. RESULTS: Both AURKB and UBE2C were significantly up-regulated in gliomas compared to normal brain tissues and the combined elevation of AURKB and UBE2C were strongly associated with histological classification in glioma. Moreover, overexpression of either AURKB or UBE2C strongly correlated to more severe overall survival. Notably, upregulation of these two genes revealed unfavorable outcomes (shorter overall survival and therapy resistance) in glioma patients with significant sensitivity and specificity. CONCLUSION: Simultaneously elevated expressions of AURKB and UBE2C was strongly correlated to poor prognosis and therapy resistance in glioma, furthermore, our data suggest for the first time that the combination of AURKB and UBE2C overexpression could be highly sensitive prognostic markers and potential therapeutic targets for glioma patients.

Polo­like kinase 4 promotes tumorigenesis and induces resistance to radiotherapy in glioblastoma.

Glioblastoma (GBM) is one of the most malignant tumors in adults, associated with severe outcomes (median survival, <2 years). Multiple mechanisms are known to be involved in tumor recurrence and treatment resistance in GBM, however, the key regulator for GBM tumorigenesis and therapy resistance remains unclear. To clarify a novel potential functional mechanism of GBM recurrence, a wide range of experiments including in vitro molecular biological experiments and in vivo intracranial xenograft tumor models were performed in the present study. With bioinformatics analysis, polo­like kinase 4 (PLK4) was initially identified as one of the most upregulated kinase encoding genes in GBM, which was functionally required for both in vitro cell proliferation and in vivo tumorigenesis in GBM. Clinically, an elevated PLK4 expression was observed in high grade glioma patients, which was associated with poor prognosis. In addition, PLK4 enhanced radioresistance in GBM, while PLK4 knockdown via lentivirus transfection significantly increased the radiosensitivity of GBM cells. Mechanically, PLK4 expression was markedly elevated by the exogenous overexpression of ATPase family AAA domain­containing protein 2 (ATAD2) in GBM cells. Collectively, the results suggested that the ATAD2­dependent transcriptional regulation of PLK4 promoted cell proliferation and tumorigenesis, as well as radioresistance in GBM, thus potentially inducing tumor recurrence. PLK4 could therefore serve as a potential therapeutic target for GBM treatment.

Nuclear factor I A promotes temozolomide resistance in glioblastoma via activation of nuclear factor κB pathway.

AIMS: To investigate the underlying mechanism by which glioblastoma (GBM) cells gain temozolomide (TMZ) resistance and to clarify novel therapeutic targets and new prognostic biomarkers for GBM. MAIN METHODS: A genome-wide hierarchical bi-clustering based on previously published microarray databases identified Nuclear Factor I A (NFIA) as one of the most significantly upregulated genes correlated to TMZ resistance in GBM. Then, the potential biological functions of NFIA in oncogenesis and chemoresistance were clarified by qRT-PCR, Western blotting and in vivo xenograft models with artificially induced TMZ-resistant U87 cells. Additionally, immunohistochemistry (IHC) assays were performed to explore the clinical significance of NFIA in glioma patients. Last, luciferase reporter assay was performed to study the transcriptional regulation of NFIA on the nuclear factor κb (NF-kB) pathway. KEY FINDINGS: NFIA was correlated with TMZ resistance in GBM. Clinically, elevated NFIA expression was significantly correlated with adverse outcomes of glioma patients, especially in GBM patients. Moreover, NFIA contributed to the acquired TMZ resistance of GBM cells, while suppression of NFIA via lentivirus reduced cell proliferation, tumorigenesis and resistance to TMZ of GBM. Additionally, NFIA promoted transcription activity that regulated the expression of NF-kB. Last, NFIA induced phosphorylation of NF-kB p65 at serine 536, thus inducing TMZ resistance in GBM cells. Altogether, our study suggests that NFIA-dependent transcriptional regulation of NF-kB contributes to acquired TMZ resistance in GBM. SIGNIFICANCE: Abnormally activated NFIA-NF-kB signaling was strongly correlated with acquired TMZ resistance and poor prognosis in GBM, and it could be a new therapeutic target for TMZ-resistant GBM.

Targeting Aurora kinase B attenuates chemoresistance in glioblastoma via a synergistic manner with temozolomide.

BACKGROUND: Recent studies have demonstrated that aberrant expression or activation of kinases results in oncogenesis of a wide range of cancers including GBM. Inhibition of kinases expression induces a reduction of therapy resistance. In this study, we investigate the underlying mechanism by which glioblastoma (GBM) cells acquire resistance to Temozolomide (TMZ) through Aurora kinase B (AURKB) thus to identify novel therapeutic targets and prognostic biomarkers for GBM. METHODS: AURKB was identified as a key candidate kinase-encoding gene in chemoresistance regulation by using kinome-wide bioinformatic analysis. Afterwards, the potential biological functions of AURKB in oncogenesis and chemoresistance were investigated by lentivirus-dependent silencing of AURKB combined with qRT-PCR, western blot and in vivo intra-cranial xenograft mice models. Additionally, immunohistochemistry (IHC) assays were performed to explore the clinical significance of AURKB in glioma patients. Lastly, Chou-Talalay method was used to confirm the synergistic effect of TMZ combined with AURKB inhibitor. RESULTS: AURKB was among the most significantly up-regulated kinase-coding genes in TMZ resistant GBM cells according to database GSE68029, moreover, an increased expression of AURKB was closely associated with poor prognosis in glioma and GBM patients. AURKB knock-down resensitized U87 resistant cells to TMZ both in vitro and in vivo. Additionally, the combination of TMZ and Hesperadin, a specific AURKB inhibitor, significantly suppressed the proliferation of TMZ resistant GBM cells thus dramatically prolonged the survival of xenograft mice viaa synergistic effect with TMZ. CONCLUSION: Elevated AURKB expression was strongly correlated to TMZ resistant acquisition and poor prognosis, furthermore, targeting AURKB would be a potential therapeutic target for GBM patients.