Aberrant DNA methylation is one of the most prevalent epigenetic alterations in cancer, and reversing DNA methylation holds promise as a therapeutic strategy. However, the function and underlying mechanisms of DNA methylation in pediatric high-grade glioma (pHGG) remain poorly understood. Here, we demonstrate that aberrant DNA methylation patterns are present in pHGG. Additionally, the overall level of DNA methylation is higher in H3/IDH wild-type pHGGs than in the H3K27-altered or H3G34R-mutant subtypes. Importantly, 5-Azacytidine, an inhibitor of DNA methyltransferases (DNMTs), significantly reduced the self-renewal capacity of pHGG cells in vitro and suppressed tumor growth in vivo by reversing DNA methylation. Furthermore, RUNX3, a putative tumor suppressor that is silenced in H3/IDH wild-type and H3K27-altered subtypes, was markedly reactivated by pharmacological or genetic induction of promoter demethylation, leading to reduced tumor growth of pHGG cells in vitro and in vivo. Notably, the antitumoral effects of combination of RUNX3 and temozolomide (TMZ) is superior to TMZ treatment alone in pHGG-derived xenografts. Collectively, our findings suggest that targeting aberrant DNA methylation may attenuate cancer stemness and inhibit tumor growth, which is associated with RUNX3 re-expression. These findings provide mechanistic insights that may inform future therapeutic development.

Purpose: Leucine-rich repeats and immunoglobulin-like domains 3 (LRIG3) functions as a tumor suppressor in glioma. Although our previous study demonstrated that LRIG3 inhibited angiogenesis via the PI3K/AKT/VEGFA pathway under normoxia, its impact on glioma vascularization under hypoxia remains elusive. Vasculogenic mimicry (VM), an alternative form of neovascularization, plays a pivotal role in glioma progression, particularly within hypoxic tumor microenvironments. This study aimed to investigate the effects of LRIG3 on hypoxia-induced VM in glioma and to elucidate the underlying molecular mechanisms. Methods: The effects of LRIG3 on VM were evaluated in vitro using tube formation and 3D spheroid invasion assays. Histological analysis of intracranial xenografts and glioblastoma specimens was performed to assess LRIG3's impact on glioma vascularization in vivo. The underlying mechanisms were investigated using western blot, quantitative real-time PCR (qRT-PCR), and ubiquitination assays. Results: LRIG3 expression was inversely correlated with VM density in the central hypoxic regions of both xenografts and glioblastoma specimens. Under hypoxia, LRIG3 overexpression inhibited the invasion and tube formation capacities of glioma cells, whereas its knockdown promoted these activities. Mechanistically, LRIG3 suppressed VM phenotypes by downregulating Snail2 at the post-translational level, rather than affecting VEGFA. LRIG3 promoted the ubiquitination of Snail2, leading to its proteasomal degradation and destabilization under hypoxia. Conclusions: LRIG3 inhibits hypoxia-induced VM in glioma by facilitating the proteasomal degradation of Snail2 via ubiquitination.

The mesenchymal subtype of glioblastoma (GBM) cells characterized by aggressive invasion and therapeutic resistance is thought to be dependent on cell-intrinsic alteration and extrinsic cellular crosstalk. Tumor-associated macrophages (TAMs) are pivotal in tumor progression, chemo-resistance, angiogenesis, and stemness maintenance. However, the impact of TAMs on the shifts in glioma stem cells (GSCs) states remains largely uncovered. Herein, we showed that the triggering receptor expressed on myeloid cells-1 (TREM1) preferentially expressed by M2-like TAMs and induced GSCs into mesenchymal-like states by modulating the secretion of TGFβ2, which activated the TGFβR/SMAD2/3 signaling in GSCs. Furthermore, we demonstrated that TREM1 was transcriptionally regulated by HIF1a under the hypoxic environment and thus promoted an immunosuppressive type of TAMs via activating the TLR2/AKT/mTOR/c-MYC axis. Collectively, this study reveals that cellular communication between TAMs and GSCs through the TREM1-mediated TGFβ2/TGFβR axis is involved in the mesenchymal-like transitions of GSCs. Our study provides valuable insights into the regulatory mechanisms between the tumor immune microenvironment and the malignant characteristics of GBM, which can lead to potential novel strategies targeting TAMs for tumor control.

ObjectiveTo construct and verificate an RNA-binding protein (RBP)-associated prognostic model for gliomas using integrated bioinformatics analysis.MethodsRNA-sequencing and clinic pathological data of glioma patients from The Cancer Genome Atlas (TCGA) database and the Chinese Glioma Genome Atlas database (CGGA) were downloaded. The aberrantly expressed RBPs were investigated between gliomas and normal samples in TCGA database. We then identified prognosis related hub genes and constructed a prognostic model. This model was further validated in the CGGA-693 and CGGA-325 cohorts.ResultsTotally 174 differently expressed genes-encoded RBPs were identified, containing 85 down-regulated and 89 up-regulated genes. We identified five genes-encoded RBPs (ERI1, RPS2, BRCA1, NXT1, and TRIM21) as prognosis related key genes and constructed a prognostic model. Overall survival (OS) analysis revealed that the patients in the high-risk subgroup based on the model were worse than those in the low-risk subgroup. The area under the receiver operator characteristic curve (AUC) of the prognostic model was 0.836 in the TCGA dataset and 0.708 in the CGGA-693 dataset, demonstrating a favorable prognostic model. Survival analyses of the five RBPs in the CGGA-325 cohort validated the findings. A nomogram was constructed based on the five genes and validated in the TCGA cohort, confirming a promising discriminating ability for gliomas.ConclusionThe prognostic model of the five RBPs might serve as an independent prognostic algorithm for gliomas.

Tumor-associated macrophages (TAMs) account for 30–50% of glioma microenvironment. The interaction between glioma tumor cells and TAMs can promote tumor progression, but the intrinsic mechanisms remain unclear. Herein, we reported that soluble LRIG3 (sLRIG3) derived from glioma tumor cells can block the M2 polarization of TAMs via interacting with NETO2, thus suppressing GBM malignant progression. The expression or activity of ADAM17 in glioma cells was positively correlated with the expression of sLRIG3 in cell supernatant. Soluble LRIG3 can suppress the M2-like polarity transformation of TAMs and inhibit the growth of tumor. High expression of LRIG3 predicts a good prognosis in patients with glioma. Mass spectrometry and Co-immunoprecipitation showed that sLRIG3 interacts with the CUB1 domain of NETO2 in TAMs. Silencing or knockout of NETO2 could block the effect of sLRIG3, which inhibited the M2-like polarity transformation of TAMs and promoted GBM tumor growth. However, overexpressing His-target NETO2 with CUB1 deletion mutation does not fully recover the suppressive effects of sLRIG3 on the TAM M2-polarization in NETO2-Knockout TAMs. Our study revealed vital molecular crosstalk between GBM tumor cells and TAMs. Glioma cells mediated the M2 polarization of TAM through the sLRIG3-NETO2 pathway and inhibited the progression of GBM, suggesting that sLRIG3-NETO2 may be a potential target for GBM treatment.

PURPOSE:To identify risk factors for major postoperative complications in meningioma patients and to construct and validate a nomogram that identify patients at high risk of these complications. METHODS:The medical records of meningioma patients who underwent surgical resection in our hospital from January 2018 to December 2020 were collected. The patients were divided into a training set (815 cases from the main campus in 2018 and 2019) and a validation set (300 cases from two other campuses in 2020). Major postoperative complications were defined as any new neurological deficits and complications classified as Clavien-Dindo Grading (CDG) II or higher. Univariate and multivariate analyses were conducted using the training set to identify independent risk factors. A nomogram was constructed based on these results. And then validated the nomogram through bootstrap re-sampling in both the training and validation sets. The concordance index (C-index) and the area under the curve (AUC) were used to assess the discriminative ability of the nomogram. The Hosmer-Lemeshow test was performed to evaluate the goodness-of-fit. The optimal cutoff point for the nomogram was calculated using Youden's index. RESULTS:In the training set, 135 cases (16.56%) experienced major postoperative complications. The independent risk factors identified were male sex, recurrent tumors, American Society of Anesthesiologists (ASA) class III-IV, preoperative Karnofsky Performance Scale (KPS) score < 80, preoperative serum albumin < 35 g/L, tumor in the skull base or central sulcus area, subtotal tumor resection (STR), allogeneic blood transfusion, and larger tumor size. A nomogram was constructed based on these risk factors. It demonstrated good predictive performance, with a C-index of 0.919 for the training set and 0.872 for the validation set. The area under the curve (AUC) > 0.7 indicated satisfactory discriminative ability. The Hosmer-Lemeshow test showed no significant deviation from the predicted probabilities. And the cutoff for nomogram total points was about 200 (specificity 0.881 and sensitivity 0.834). CONCLUSIONS:The constructed nomogram demonstrated robust predictive performance for major postoperative complications in meningioma patients. This model can be used by surgeons as a reference in clinical decision-making.

Abstract Background Glioma stem cells (GSCs) are a subpopulation of tumor cells with self-renewal and tumorigenic capabilities in glioblastomas (GBMs). Diffuse infiltration of GSCs facilitates tumor progression and frustrates efforts at effective treatment. Further compounding this situation is the currently limited understanding of what drives GSC invasion. Here we comprehensively evaluated the significance of a novel invasion-related protein, Family with Sequence Similarity 129 Member A (FAM129A), in infiltrative GSCs. Methods Western blotting, immunohistochemistry, and gene expression analysis were used to quantify FAM129A in glioma specimens and cancer datasets. Overexpression and knockdown of FAM129A in GSCs were used to investigate its effects on tumor growth and invasion. RNA-seq, qRT-PCR, western blotting, and co-precipitation assays were used to investigate FAM129A signaling mechanisms. Results FAM129A is preferentially expressed in invasive frontiers. Targeting FAM129A impairs GSC invasion and self-renewal. Mechanistically, FAM129A acted as a positive regulator of Notch signaling by binding with the Notch1 intracellular domain (NICD1) and preventing its degradation. Conclusions FAM129A and NICD1 provide a precise indicator for identifying tumor margins and aiding prognosis. Targeting them may provide a significantly therapeutic strategy for GSCs.

Subsequently to the publication of the above article and a Corrigendum that addressed the issue of a misspelling of one of the authors' names (DOI: 10.3892/ijo.2019.4769; published online on April 2, 2019), the authors have subsequently discovered that Fig. 7 on p. 1079 contained a duplication in two of the panels that might cause the readers some confusion. The authors were able to re-examine the original data, repeat the experiment, and have decided to revise Fig. 7. The corrected version of Fig. 7, showing replacement data for the p-Akt and Cyclin D1 experiments, is shown on the next page. The authors confirm that these data continue to support the main conclusions presented in their paper, and are grateful to the Editor of International Journal of Oncology for allowing them this opportunity to publish a Corrigendum. They also apologize to the readership for any inconvenience caused. [the original article was published in International Journal of Oncology 10.3892/ijo.2018.4482].

Background The tightly controlled activity of EGFR is important for the homeostasis of self-renewal of human tissue. Mutations in the extracellular domain of EGFR are frequent and function as a novel mechanism for oncogenic EGFR activation in GBM, and impact the response of patients to small-molecule inhibitors. Methods We constructed glioblastoma cell lines stably expressing wild-type EGFR and the mutant of EGFR S645C. We detected cell growth in vitro and in vivo. We evaluated the anti-tumor activity and effectiveness of gefitinib and osimertinib in cells. Results In the present study, we identified an oncogenic substituted mutation of EGFR—S645C. The mutation can promote the proliferation and colony formation of glioblastoma in vitro and in vivo. Mechanistically, the EGFR S645C mutation potentially changes the formation of hydrogen bonds within dimerized EGFR and inhibits the degradation of EGFR to prolong downstream signaling. The mutation induces resistance to gefitinib but presents an opportunity for osimertinib treatment. Conclusion The study indicated a novel oncogenic mutation and advises on the precise treatment of individual patients with the EGFR S645C mutation.

Rationale: In the glioblastoma (GBM) microenvironment, tumor-associated macrophages (TAMs) are prominent components and facilitate tumor growth. The exact molecular mechanisms underlying TAMs' function in promoting glioma stem cells (GSCs) maintenance and tumor growth remain largely unknown. We found a candidate molecule, transforming growth factor beta-induced (TGFBI), that was specifically expressed by TAMs and extremely low in GBM and GSC cells, and meanwhile closely related to glioma WHO grades and patient prognosis. The exact mechanism of TGFBI linking TAM functions to GSC-driven tumor growth was explored. Methods: Western blot, quantitative real-time PCR (qRT-PCR), enzyme-linked immunosorbent assay (ELISA), immunofluorescence (IF), immunohistochemistry staining (IHC) and public datasets were used to evaluate TGFBI origin and level in GBM. The response of GSCs to recombinant human TGFBI was assessed in vitro and orthotopic xenografts were established to investigate the function and mechanism in vivo. Results: M2-like TAMs infiltration was elevated in high-grade gliomas. TGFBI was preferentially secreted by M2-like TAMs and associated with a poor prognosis for patients with GBM. TGFBI promoted the maintenance of GSCs and GBM malignant growth through integrin αvβ5-Src-Stat3 signaling in vitro and in vivo. Of clinical relevance, TGFBI was enriched in the serum and CSF of GBM patients and significantly decreased after tumor resection. Conclusion: TAM-derived TGFBI promotes GSC-driven tumor growth through integrin αvβ5-Src-Stat3 signaling. High serum or CSF TGFBI may serve as a potential diagnostic and prognostic bio-index for GBMs.

Abstract Glioblastoma (GBM) is a common and fatal disease of the central nervous system. It has a worldwide occurrence and affects people from diverse backgrounds. GBM cell lines are fundamental tools used in GBM research. The establishment of novel continuous GBM cell lines with clear genetic backgrounds could facilitate the exploration of molecular mechanisms and the screening and evaluation of antitumor drugs in GBM studies. Here, we established a novel primary glioblastoma cell line, named GWH04, from a patient with glioblastoma, and examined its short-tandem repeat (STR) genotype and various tumor parameters. The STR information of GWH04 was identical to that of the original primary tumor tissue. Compared with existing cell lines, GWH04 had a similar in vitro proliferation rate as U87 cell line, but a faster rate than GL15 cell line, and a substantial soft agar clone formation capacity. GWH04 showed subcutaneous and intracranial tumorigenic capacity, with an aneuploid karyotype and median 84 chromosomes. Gene sequencing further revealed the mutational status of genes TP53, PTEN, PDGFRA, ERBB2, BRCA1, NF1, and MLH1 and the promoter region of TERT (C228T) in this cell line. Altogether, these results indicate that GWH04 can facilitate human GBM studies both in vitro and in vivo.

Efforts in the treatment of glioma which is the most common primary malignant tumor of the central nervous system, have not shown satisfactory results despite a comprehensive treatment model that combines various treatment methods, including immunotherapy. Cellular metabolism is a determinant of the viability and function of cancer cells as well as immune cells, and the interplay of immune regulation and metabolic reprogramming in tumors has become an active area of research in recent years. From the perspective of metabolism and immunity in the glioma microenvironment, we elaborated on arginine metabolic reprogramming in glioma cells, which leads to a decrease in arginine levels in the tumor microenvironment. Reduced arginine availability significantly inhibits the proliferation, activation, and function of T cells, thereby promoting the establishment of an immunosuppressive microenvironment. Therefore, replenishment of arginine levels to enhance the anti-tumor activity of T cells is a promising strategy for the treatment of glioma. However, due to the lack of expression of argininosuccinate synthase, gliomas are unable to synthesize arginine; thus, they are highly dependent on the availability of arginine in the extracellular environment. This metabolic weakness of glioma has been utilized by researchers to develop arginine deprivation therapy, which ‘starves’ tumor cells by consuming large amounts of arginine in circulation. Although it has shown good results, this treatment modality that targets arginine metabolism in glioma is controversial. Exploiting a suitable strategy that can not only enhance the antitumor immune response, but also “starve” tumor cells by regulating arginine metabolism to cure glioma will be promising.

Abstract Background Alternative splicing (AS), one of the main post-transcriptional biological regulation mechanisms, plays a key role in the progression of glioblastoma (GBM). Systematic AS profiling in GBM is limited and urgently needed. Methods TCGA SpliceSeq data and the corresponding clinical data were downloaded from the TCGA data portal. Survival-related AS events were identified through Kaplan–Meier survival analysis and univariate Cox analysis. Then, splicing correlation network was constructed based on these AS events and associated splicing factors. LASSO regression followed by multivariate Cox analysis was performed to validate independent AS biomarkers and to construct a risk prediction model. Enrichment analysis was subsequently conducted to explore potential signaling pathways of these AS events. Results A total of 132 TCGA GBM samples and 45,610 AS events were included in our study, among which 416 survival-related AS events were identified. An AS correlation network, including 54 AS events and 94 splicing factors, was constructed, and further functional enrichment was performed. Moreover, the novel risk prediction model we constructed displayed moderate performance (the area under the curves were > 0.7) at both one, two and three years. Conclusions Survival-related AS events may be vital factors of both biological function and prognosis. Our findings in this study can deepen the understanding of the complicated mechanisms of AS in GBM and provide novel insights for further study. Moreover, our risk prediction model is ready for preliminary clinical applications. Further verification is required.

High levels of microvessel density (MVD) indicate poor prognosis in patients with malignant glioma. Leucine-rich repeats and immunoglobulin-like domains (LRIG) 3, a potential tumor suppressor, plays an important role in tumor progression and may serve as a biomarker in many human cancers. However, its role and underlying mechanism of action in glioma angiogenesis remain unclear. In the present study, we used loss- and gain-of-function assays to show that LRIG3 significantly suppressed glioma-induced angiogenesis, both in vitro and in vivo. Mechanistically, LRIG3 inhibited activation of the PI3K/AKT signaling pathway, downregulating vascular endothelial growth factor A (VEGFA) in glioma cells, thereby inhibiting angiogenesis. Notably, LRIG3 had a significant negative correlation with VEGFA expression in glioma tissues. Taken together, our results suggest that LRIG3 is a novel regulator of glioma angiogenesis and may be a promising option for developing anti-angiogenic therapy.

Abstract 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.

Background Despite psychiatric traits were associated with intracranial aneurysms (IAs) in observational studies, their causal relationships remain largely undefined. We aimed to assess the causality between psychiatric traits and IAs. Methods We firstly collected the genome-wide association statistics of IAs (sample size, n = 79,429) and ten psychiatric traits from Europeans, including insomnia (n = 1,331,010), mood instability (n = 363,705), anxiety disorder (n = 83,566), major depressive disorder (MDD) (n = 480,359), subjective wellbeing (n = 388,538), attention deficit/hyperactivity disorder (ADHD) (n = 53,293), autism spectrum disorder (ASD) (n = 46,350), bipolar disorder (BIP) (n = 51,710), schizophrenia (SCZ) (n = 105,318), and neuroticism (n = 168,105). We then conducted a series of bi-directional two-sample Mendelian randomization (MR) analyses, of which the Robust Adjusted Profile Score (RAPS) was the primary method to estimate the causal effects between these psychiatric traits and IAs. Results We found that insomnia exhibited a significant risk effect on IAs with the odds ratio (OR) being 1.22 (95% CI: 1.11–1.34, p = 4.61 × 10–5) from the RAPS method. There was suggestive evidence for risk effect of mood instability on IAs (RAPS, OR = 4.16, 95% CI: 1.02–17.00, p = 0.047). However, no clear evidence of causal effects on IAs for the rest eight psychiatric traits (anxiety disorder, MDD, subjective wellbeing, ADHD, ASD, BIP, SCZ, and neuroticism) was identified. In the reverse MR analyses, no causal effects of IAs on psychiatric traits were found. Conclusions Our findings provide strong evidence for a causal risk effect of insomnia on IAs and suggestive evidence for mood instability as a causal risk effect on IAs. These results could inform the prevention and clinical intervention of IAs.

Primary meningeal melanocytoma （MM） in the cerebellopontine angle （CPA） region is an extremely rare neoplasm that originates from the melanocytes in the leptomeninges.These lesions are usually misdiagnosed as they mimic other common CPA lesions through their nonspecific presenting symptoms,signs,and radiological characteristics.Here,we report a 47-year-old Chinese female patient who presented with a 1-month history of the right-sided tongue numbness and 1-week history of the right-sided face numbness that had been worsening for 2 days.The tumor,in the right CPA region,showed a slight isointensity on T1-weighted image and mixed signal intensity on T2-weighted image.The clinical presentation,surgical treatment,and pathologic characteristics were determined.The tumor was microsurgically resected and gross-total resection was achieved.The tumor revealed a solid,capsulated,brown-black lesion.Immunohistochemistry showed that the tumor cells were positive for human melanoma black-45 （HMB-45）,melanoma antigen （MelanA）,S100,SOX10,and BRAF,confirming the final diagnosis of meningeal melanocytoma.Ultimately,no signs of radiological local recurrence were observed during the two-year follow-up.Collectively,meningeal melanocytoma is difficult to distinguish from common tumors in the CPA region before operation due to the lack of specificity in imaging and symptoms.Complete surgical resection is the best therapeutic option for this tumor.Although the tumor is commonly considered as a benign lesion,recurrence and metastasis are common,and pathogenesis remains unclear.

[This corrects the article DOI: 10.3389/fonc.2019.00447.].

[This corrects the article DOI: 10.3389/fonc.2019.00447.].

BACKGROUND:This study aimed to evaluate and compare the neurocognitive outcomes of adult quasi-moyamoya disease (quasi-MMD) patients with autoimmune diseases (AIDs) to help better manage these patients. METHODS:We performed a structured battery of neurocognitive tests to analyze and compare the neurocognitive outcomes of adult quasi-MMD patients with AID in our hospital from October 2000 to September 2015. RESULTS:Overall, 27.3% of the neuropsychological test comparisons indicated a significant improvement in cognition, and a significant decline was found in 6%. In 47.4% of comparisons, the observed difference did significantly change the reliable change indices (RCI) before and after anti-autoimmune treatment. We found that the number of patients showing significant improvements, and no change in cognitive outcomes did differ between quasi-MMD and MMD (31.8% vs 14.9% with p = 0.006 and 50.0% vs 66.8% with p = 0.031, respectively; Chi-squared test). The incidence of cognitive decline in quasi-MMD patients (18.2%) did not significantly differ from that in MMD patients (18.3%) (p = 0.982). After adjusting for covariates, including sex, age, type 2 diabetes mellitus, risk factors, other comorbidities, and AID, multiple logistic regression analysis suggested that AID was more likely to aggravate the neurocognitive outcome of quasi-MMD patients (p = 0.042, odds ratio (OR) 6.78, 95% confidence interval (CI) 1.31-62.71). CONCLUSIONS:AID was more likely to aggravate the neurocognitive outcome of quasi-MMD patients, and anti-autoimmune treatment could improve long-term neurocognitive outcomes. These findings indicated that AID seemed to be an independent risk factor for the pathological and physiological mechanisms of quasi-MMD.