Protein arginine methyltransferase 1 (PRMT1), the predominant type I protein arginine methyltransferase, plays a crucial role in normal biological functions by catalyzing the methylation of arginine side chains, specifically monomethylarginine (MMA) and asymmetric dimethylarginine (ADMA), within proteins. Recent investigations have unveiled an association between dysregulated PRMT1 expression and the initiation and progression of tumors, significantly impacting patient prognosis, attributed to PRMT1’s involvement in regulating various facets of tumor cell biology, including DNA damage repair, transcriptional and translational regulation, as well as signal transduction. In this review, we present an overview of recent advancements in PRMT1 research across different tumor types, with a specific focus on its contributions to tumor cell proliferation, metastasis, invasion, and drug resistance. Additionally, we expound on the dynamic functions of PRMT1 during distinct stages of cancer progression, elucidating its unique regulatory mechanisms within the same signaling pathway and distinguishing between its promotive and inhibitory effects. Importantly, we sought to provide a comprehensive summary and analysis of recent research progress on PRMT1 in tumors, contributing to a deeper understanding of its role in tumorigenesis, development, and potential treatment strategies.

Glioblastoma is the most common malignant tumor in the central nervous system and its occurrence and development is involved in various molecular abnormalities. C-X-C chemokine ligand 10 (CXCL10), an inflammatory chemokine, has been reported to be related to the pathogenesis of cancer while it has not yet been linked to glioma. Calycosin, a bioactive compound derived from Radix astragali, has demonstrated anticancer properties in several malignancies, including glioma. Nonetheless, its underlying mechanisms are not fully understood. This study explores CXCL10 as a potential therapeutic target for calycosin in the suppression of glioblastoma. We observed that CXCL10 expression correlates positively with glioma malignancy and inversely with patient prognosis, highlighting its potential as a glioblastoma treatment target. Furthermore, we found that calycosin inhibited proliferation, migration, and invasion in U87 and U251 glioma cells, and decreased CXCL10 expression in a dose-dependent manner, along with its downstream effectors such as NLRP3, NF-κB, and IL-1β. Additionally, molecular docking experiments demonstrated that calycosin exhibits a notable binding affinity to CXCL10. Overexpression of CXCL10 counteracted the inhibitory effects of calycosin on cell proliferation, migration, and invasion, while CXCL10 knockdown enhanced these effects. Finally, we verified that calycosin inhibited glioma growth in a xenograft mouse model and downregulated CXCL10 and its downstream molecules. These findings suggest that targeting CXCL10 may be an effective strategy in glioblastoma treatment, and calycosin emerges as a potential therapeutic agent.

Invasion and migration are the key hallmarks of cancer, and aggressive growth is a major factor contributing to treatment failure and poor prognosis in glioblastoma. Protein arginine methyltransferase 6 (PRMT6), as an epigenetic regulator, has been confirmed to promote the malignant proliferation of glioblastoma cells in previous studies. However, the effects of PRMT6 on glioblastoma cell invasion and migration and its underlying mechanisms remain elusive. Here, we report that PRMT6 functions as a driver element for tumor cell invasion and migration in glioblastoma. Bioinformatics analysis and glioma sample detection results demonstrated that PRMT6 is highly expressed in mesenchymal subtype or invasive gliomas, and is significantly negatively correlated with their prognosis. Inhibition of PRMT6 (using PRMT6 shRNA or inhibitor EPZ020411) reduces glioblastoma cell invasion and migration in vitro, whereas overexpression of PRMT6 produces opposite effects. Then, we identified that PRMT6 maintains the protein stability of EZH2 by inhibiting the degradation of EZH2 protein, thereby mediating the invasion and migration of glioblastoma cells. Further mechanistic investigations found that PRMT6 inhibits the transcription of TRAF6 by activating the histone methylation mark (H3R2me2a), and reducing the interaction between TRAF6 and EZH2 to enhance the protein stability of EZH2 in glioblastoma cells. Xenograft tumor assay and HE staining results showed that the expression of PRMT6 could promote the invasion of glioblastoma cells in vivo, the immunohistochemical staining results of mouse brain tissue tumor sections also confirmed the regulatory relationship between PRMT6, TRAF6, and EZH2. Our findings illustrate that PRMT6 suppresses TRAF6 transcription via H3R2me2a to enhance the protein stability of EZH2 to facilitate glioblastoma cell invasion and migration. Blocking the PRMT6-TRAF6-EZH2 axis is a promising strategy for inhibiting glioblastoma cell invasion and migration.

Platelet-derived growth factor receptor β positive (PDGFRβ+) pericytes detach from the microvascular wall and migrate into the injury center following spinal cord injury (SCI), which has been widely regarded as the main source of fibrotic scar, but the mechanism of migration and fibroblast transition remains elusive. Here we show the associated spatiotemporal distribution between microglia and pericytes at three and seven days post-injury (dpi). The increased expression of Sphingosine kinase-1 (SPHK1) in microglia significantly raised the concentration of Sphingosine-1-phosphate (S1P) in the spinal cord, which promotes migration and fibroblast transition of pericyte. In vitro experiments, we found the elevated Sphingosine 1-phosphate receptor 3 (S1P3), the S1P/S1PR3 axis inhibited the phosphorylation of YAP and promoted its nuclear translocation, which contributed to the formation of alpha-smooth muscle actin (α-SMA) and collagen type I (COL1) protein, This process can be blocked by an S1P3 specific inhibitor TY52156 in vitro. The S1P/S1P3/YAP pathway might be a potential target for treatment in SCI.

The role of SLC3A2, a gene implicated in disulfidptosis, has not been characterized in gliomas. This study aims to clarify the prognostic value of SLC3A2 and its influence on glioma. We evaluated the expression of SLC3A2 and its prognostic importance in gliomas using publicly accessible databases and our clinical glioma samples and with reliance on Meta and Cox regression analysis approaches. Functional enrichment analyses were performed to explore SLC3A2's function. Immune infiltration was evaluated using CIBERSORT, ssGSEA, and single-cell sequencing data. Additionally, Tumor immune dysfunction and exclusion (TIDE) and epithelial-mesenchymal transition scores were determined. CCK8, colony formation, migration, and invasion assays were utilized in vitro, and an orthotopic glioma xenograft model was employed in vivo, to investigate the role of SLC3A2 in gliomas. Bioinformatics analyses indicated high SLC3A2 expression correlates with adverse clinicopathological features and poor patient prognosis. Upregulated SLC3A2 influenced the tumor microenvironment by altering immune cell infiltration, particularly of macrophages, and tumor migration and invasion. SLC3A2 expression positively correlated with immune therapy indicators, including immune checkpoints and TIDE. Elevated SLC3A2 was revealed as an independent risk element for poor glioma prognosis through Cox regression analyses. In vitro experiments showed that reduced SLC3A2 expression decreased cell proliferation, migration, and invasion. In vivo, knockdown of SLC3A2 led to a reduction in tumor volume and prolonged survival in tumor-bearing mice. Therefore, SLC3A2 is a prognostic biomarker and associated with immune infiltration in gliomas.

BACKGROUND:Gliomas are the most frequently diagnosed primary brain tumors, and are associated with multiple molecular aberrations during their development and progression. GPR37 is an orphan G protein-coupled receptor (GPCR) that is implicated in different physiological pathways in the brain, and has been linked to various malignancies. The aim of this study was to explore the relationship between GPR37 gene expression and the clinicopathological factors, patient prognosis, tumor-infiltrating immune cell signature GSEA and methylation levels in glioma.METHODS:We explored the diagnostic value, clinical relevance, and molecular function of GPR37 in glioma using TCGA, STRING, cBioPortal, Tumor Immunity Estimation Resource (TIMER) database and MethSurv databases. Besides, the "ssGSEA" algorithm was conducted to estimate immune cells infiltration abundance, with 'ggplot2' package visualizing the results. Immunohistochemical staining of clinical samples were used to verify the speculations of bioinformatics analysis.RESULTS:GPR37 expression was significantly higher in the glioma tissues compared to the normal brain tissues, and was linked to poor prognosis. Functional annotation of GPR37 showed enrichment of ether lipid metabolism, fat digestion and absorption, and histidine metabolism. In addition, GSEA showed that GPR37 was positively correlated to the positive regulation of macrophage derived foam cell differentiation, negative regulation of T cell receptor signaling pathway, neuroactive ligand receptor interaction, calcium signaling pathway, and negatively associated with immunoglobulin complex, immunoglobulin complex circulating, ribosome and spliceosome mediated by circulating immunoglobulin etc. TIMER2.0 and ssGSEA showed that GPR37 expression was significantly associated with the infiltration of T cells, CD8 T cell, eosinophils, macrophages, neutrophils, NK CD56dim cells, NK cells, plasmacytoid DCs (pDCs), T helper cells and T effector memory (Tem) cells. In addition, high GPR37 expression was positively correlated with increased infiltration of M2 macrophages, which in turn was associated with poor prognosis. Furthermore, GPR37 was positively correlated with various immune checkpoints (ICPs). Finally, hypomethylation of the GPR37 promoter was associated with its high expression levels and poor prognosis in glioma.CONCLUSION:GPR37 had diagnostic and prognostic value in glioma. The possible biological mechanisms of GPR37 provide novel insights into the clinical diagnosis and treatment of glioma.

Mangiferin, a natural C-glucoside xanthone, is one of the major bioactive ingredients derived from the dry rhizome of Anemarrhenae rhizome, which has been reported to exhibit various pharmacological effects, including anti-oxidant, anti-inflammatory, anti-fatty liver, anti-metabolic syndrome, and anti-diabetic. However, the precise molecular mechanisms underlying its impact on phospholipid metabolism in the erythrocyte membrane of type 2 diabetes mellitus (T2DM) remain unclear. The present research aimed to evaluate the effects of mangiferin on glucose and lipid metabolism in T2DM model rats and discuss the relationship between lipid metabolites and potential targets involved in the hypoglycemic effects by integrating lipidomics and network pharmacology method. After 8 consecutive weeks of treatment with mangiferin, the T2DM model rats exhibited significant improvements in several biochemical indices and cytokines, including fasting blood glucose (FBG) levels after 12 h of fasting, fasting insulin level (FINS), total cholesterol (T-CHO), triacylglycerols (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), homeostasis model assessment of insulin resistance (HMOA-IR), TNF-α and IL-6. A total of 22 differential lipid metabolites were selected from erythrocyte membrane phospholipids, which were closely associated with the processes of T2DM. These metabolites mainly belonged to glycerophospholipid metabolism and sphingolipid metabolism. Based on network pharmacology analysis, 22 genes were recognized as the potential targets of mangiferin against diabetes. Moreover, molecular docking analysis revealed that the targets of TNF, CASP3, PTGS2, MMP9, RELA, PLA2G2A, PPARA, and NOS3 could be involved in the modulation of inflammatory signaling pathways and arachidonic acid (AA) metabolism to improve IR and hyperglycemia. The combination of immunohistochemical staining and PCR showed that mangiferin could treat T2DM by regulating the expression of PPARγ protein and NF-κB mRNA expression to impact glycerophospholipids (GPs) and AA metabolism. The present study showed that mangiferin might alleviate IR and hyperglycemia of T2DM model rats via multiple targets and multiple pathways to adjust their phospholipid metabolism, which may be the underlying mechanism for mangiferin in the treatment of T2DM.

BACKGROUND:Leukocyte immunoglobulin-like receptor subfamily B1 (LILRB1) is regarded as an inhibitory molecule. However, the importance of LILRB1 expression in glioma has not yet been determined. This investigation examined the immunological signature, clinicopathological importance and prognostic value of LILRB1 expression in glioma.METHODS:We used data from the UCSC XENA database, the Cancer Genome Atlas (TCGA) database, the Chinese Glioma Genome Atlas (CGGA) database, the STRING database, the MEXPRESS database and our clinical glioma samples to perform bioinformatic analysis and used vitro experiments to examine the predictive value and potential biological roles of LILRB1 in glioma.RESULTS:Higher LILRB1 expression was considerably present in the higher WHO grade glioma group and was linked to a poorer prognosis in patients with glioma. Gene set enrichment analysis (GSEA) revealed that LILRB1 was positively correlated with the JAK/STAT signaling pathway. LILRB1 combined with tumor mutational burden (TMB) and microsatellite instability (MSI) may be a promising indicator for the effectiveness of immunotherapy in patients with glioma. Increased LILRB1 expression was positively linked with the hypomethylation, M2 macrophage infiltration, immune checkpoints (ICPs) and M2 macrophage makers. Univariate and multivariate Cox regression analyses determined that increased LILRB1 expression was a standalone causal factor for glioma. Vitro experiments determined that LILRB1 positively enhanced the proliferation, migration and invasion in glioma cells. MRI images demonstrated that higher LILRB1 expression was related with larger tumor volume in patients with glioma.CONCLUSION:Dysregulation of LILRB1 in glioma is correlated with immune infiltration and is a standalone causal factor for glioma.

Epithelial-to-mesenchymal transition (EMT) and angiogenesis have emerged as two pivotal events in cancer progression. Paeoniflorin has been widely studied in experimental models and clinical trials for cancer treatment because of its anti-cancer property. However, the underlying mechanisms of paeoniflorin in EMT and angiogenesis in glioblastoma was not fully elucidated. The present study aimed to investigate whether paeoniflorin inhibits EMT and angiogenesis, which involving c-Met suppression, while exploring the potential ways of c-Met degradation. In our study, we found that paeoniflorin inhibited EMT via downregulating c-Met signaling in glioblastoma cells. Furthermore, overexpressing c-Met in glioblastoma cells abolished the effects of paeoniflorin on EMT. Moreover, paeoniflorin showed anti-angiogenic effects by suppressing cell proliferation, migration, invasion and tube formation through downregulating c-Met in human umbilical vein endothelial cells (HUVECs). And c-Met overexpression in HUVECs offset the effects of paeoniflorin on angiogenesis. Additionally, paeoniflorin induced autophagy activation involving mTOR/P70S6K/S6 signaling and promoted c-Met autophagic degradation, a process dependent on K63-linked c-Met polyubiquitination. Finally, paeoniflorin suppressed mesenchymal makers (snail, vimentin, N-cadherin) and inhibited angiogenesis via the identical mechanism in an orthotopic xenograft mouse model. The in vitro and in vivo experiments showed that paeoniflorin treatment inhibited EMT, angiogenesis and activated autophagy. What’s more, for the first time, we identified c-Met may be a potential target of paeoniflorin and demonstrated paeoniflorin downregulated c-Met via K63-linked c-Met polyubiquitination-dependent autophagic degradation. Collectively, these findings indicated that paeoniflorin inhibits EMT and angiogenesis via K63-linked c-Met polyubiquitination-dependent autophagic degradation in human glioblastoma.

BACKGROUND:Echinacoside (ECH) is a phenylethanoid extracted from the stems of Cistanches salsa, an herb used in Chinese medicine formulations, and is effective against glioblastoma multiforme (GBM). Epithelial-mesenchymal transition (EMT) is the cornerstone of tumorigenesis and metastasis, and increases the malignant behavior of GBM cells. The S phase kinase-related protein 2 (skp2), an oncoprotein associated with EMT, is highly expressed in GBM and significantly associated with drug resistance, tumor grade and dismal prognosis. The aim of this study was to explore the inhibitory effects of ECH against GBM development and skp2-induced EMT.METHODS:CCK-8, EdU incorporation, transwell, colony formation and sphere formation assays were used to determine the effects of ECH on GBM cell viability, proliferation, migration and invasion in vitro. The in vivo anti-glioma effects of ECH were examined using a U87 xenograft model. The expression levels of skp2 protein, EMT-associated markers (vimentin and snail) and stemness markers (Nestin and sox2) were analyzed by immunofluorescence staining and western blotting experiments.RESULTS:ECH suppressed the proliferation, invasiveness and migration of GBM cells in vitro, as well as the growth of U87 xenograft in vivo. In addition, ECH downregulated the skp2 protein, EMT-related markers (vimentin and snail) and stemness markers (sox2 and Nestin). The inhibitory effects of ECH were augmented in the skp2-knockdown GBM cells, and reversed in cells with ectopic expression of skp2.CONCLUSION:ECH inhibits glioma development by suppressing skp2-induced EMT of GBM cells.

Background: Glioblastoma (GBM) is a tumor of the central nervous system with an extremely poor prognosis. Stemness and EMT play important roles in GBM progression. 3-benzyl-5-((2-nitrophenoxy) methyl) dihydrofuran-2(3H)-one (3BDO), an autophagy inhibitor, has been reported to exert anti-cancer activities on lung carcinoma. However, the effects of 3BDO on GBM remain unknown. Therefore, the purpose of this study was to explore the effects of 3BDO on GBM and to investigate the underlying molecular mechanisms. Method: CCK-8 experiments and clone formation assays were conducted to determine the level of cell proliferation. Transwell assay was conducted to examine cell migration and invasion abilities. Western blotting and immunofluorescence staining were used to analyze protein expression levels. A xenograft mouse model was used to evaluate the effect of 3BDO in vivo. Results: We found that 3BDO inhibited U87 and U251 cell proliferation in a dose-dependent manner. Additionally, 3BDO decreased the degree of sphere formation and levels of stemness markers (sox2, nestin, and CD133) in GSCs. 3BDO also inhibited migration and invasion abilities and suppressed EMT markers (N-cadherin, vimentin, and snail) in GBM cells. Moreover, we found that 3BDO downregulated the expression of survivin in both GBM cells (U87, U251) and GSCs. Furthermore, overexpression of survivin decreased the therapeutic effect of 3BDO on EMT, invasion, migration, and proliferation of GBM cells, as well as decreased the stemness of GSCs. Finally, we demonstrated that 3BDO could inhibit tumor growth in a tumor xenograft mouse model constructed using U87 cells. Similar to the in vitro findings, 3BDO decreased the expression of survivin, EMT makers, and the degree of stemness in vivo. Conclusions: Our results demonstrate that 3BDO can repress GBM both in vitro and in vivo via downregulating survivin-mediated stemness and EMT.

目的 探究大鼠原代星形胶质细胞体外牵张损伤后微小核糖核酸(microRNA)表达谱差异,并通过生物信息学分析预测差异表达microRNA在星形胶质细胞被损伤诱导活化后的作用.方法 使用细胞损伤控制仪Ⅱ型构建大鼠原代星形胶质细胞体外牵张损伤模型,阀门压力设置为40 PSI,模拟重型颅脑损伤.损伤后24 h收集对照组及损伤组星形胶质细胞总RNA,使用Agilent microRNA芯片检测差异表达microRNA,通过R语言软件构建火山图及聚类分析热图;利用DIANA TOOLS和miRDB数据库预测microRNA的靶基因,并对靶基因集进行基因本体论(GO)和京都基因和基因组百科全书(KEGG)富集分析;使用STRING数据库构建蛋白互作(PPI)网络,应用Cytoscape软件筛选关键基因.结果 大鼠原代星形胶质细胞体外牵张损伤24 h后共有9个microRNA差异表达[| Log2 Fold Change(FC)|≥0.26,P＜0.05],其中5个表达上调,分别是rno-miR-34a-5p、rno-miR-34b-5p、rno-miR-129-5p、rno-miR-140-3p 和 rno-miR-7a-5p;4 个表达下调,分别是 rno-miR-199a-3p、rno-miR-199a-5p、rno-miR-221-3p 和 rno-miR-1306-3p.rno-miR-34b-5p 差异表达倍数最为显著,对其进行靶基因预测共获得154个基因,进一步的GO和KEGG富集分析发现,rno-miR-34b-5p靶基因参与蛋白磷酸酶2A结合及磷脂酶C活性正向调节,并调控磷脂酶D信号通路、MAPK信号通路及PI3K-AKT信号通路,与颅脑创伤(TBI)后神经修复及再生密切相关.同时使用靶基因集构建PPI网络,筛选5个关键基因,分别为Tp53、Notch 1、Ki tlg、Pdgfrb和Pdgfra.结论 大鼠原代星形胶质细胞体外牵张损伤后rno-miR-34b-5p显著升高,生物信息学预测rno-miR-34b-5p靶向抑制Notch1及PDGFRA基因的表达,降低PI3K-AKT信号通路活性,可能使损伤星形胶质细胞向A1型转化,阻碍TBI后神经修复及再生.本研究为TBI后康复治疗提供了潜在的作用新靶点及新的研究方向.

Currently, exosomes (EXOs) are being explored as novel drug delivery carriers with greater advantages, including crossing the blood-brain-barrier and loading drugs. The present study utilized EXOs derived from neural stem cells (NSCs) for the delivery of molecular drugs to treat gliomas. miR-124-3p was selected according to previous studies by the authors, and the effects of the delivery of miR-124-3p to glioma cells by NSC-EXOs in vitro and in vivo were evaluated. It was found that NSC-EXOs successfully delivered miR-124-3p into glioma cells, and NSC-EXOs loaded with miR-124-3p significantly inhibited glioma cell proliferation, invasion and migration. Furthermore, the delivery of miR-124-3p by NSC-EXOs suppressed flotillin 2 (FLOT2) expression by specifically binding to the 3' untranslated region of the FLOT2 gene in gliomas; subsequently, AKT1 was found to be associated with the EXO-miR-124-3p/FLOT2 pathway. Moreover, the therapeutic effects of the delivery of miR-124-3p by NSC-EXOs were confirmed in a mouse tumor xenograft model of glioma. Thus, bio-carrier NSC-EXOs loaded with miR-124-3p suppressed glioma growth via the EXO-miR-124-3p/FLOT2/AKT1 pathway. On the whole, the present study provides insight into stem cell-free molecular-targeted therapy based on bio-carrier NSC-EXOs and provides a potential strategy for the treatment of glioma.

Abstract BackgroundGlioblastoma (GBM) is a tumor of the central nervous system carries an extremely poor prognosis. Unfortunately, it also is the most frequently encountered tumor in this region. These tumors arise from glioblastoma stem cells (GSCs), which are glioma cells that are known to possess high degrees of stemness. GBM invades through the process of EMT, which features loss of cell differentiation and polarity. Survivin is a type of apoptotic inhibitor that has been characterized in several malignancies such as glioma. Normal tissues rarely express survivin. On the other hand, 3-benzyl-5-((2-nitrophenoxy) methyl) dihydrofuran-2(3H)-one (3BDO) represents an autophagy inhibitor and activates the mTOR pathway. It has been reported that 3BDO shows anti-cancer activities in lung carcinoma. However, the effects of 3BDO on GBM reminds unknown. Therefore, the purpose of this study was to explore the role and molecular mechanisms that 3BDO mediates in GBM.MethodCCK-8 experiments and clone formation assay were performed to detect the cell proliferation. Transwell assay was conducted to examined cell migration and invasion. Western blotting and immunofluorescence staining was used to analyze protein expression levels. Xenograft mouse model was used to evaluate the effect of 3BDO in vivo.ResultsWe found that 3BDO inhibited U87 and U251 cell proliferation in a dose-dependent manner. Additonally, 3BDO decreased the sphere formation and stemness markers (sox2, nestin and CD133) in GSCs. 3BDO also inhibited migration, invasion and suppressed EMT markers (N-cadherin, vimentin and snail) in GBM cells. Moreover, we found that 3BDO downregulated survivin expression of survivin both in GBM cells (U87, U251) and GSCs. Furthermore, overexpression of survivin reduced the therapeutic effects of 3BDO on GBM cell EMT, invasion, migration and proliferation, as well as decreased stemness in GSCs. Finally, we demonstrated that 3BDO inhibited tumor growth in a tumor xenograft mouse model constructed using U87 cells. Similar to the in vitro findings, 3BDO diminished suvivin expression, stemness and levels of EMT makers in vivo.Conclusionsour results demonstrated that 3BDO repressed GBM via downregulating survivin-mediated stemness and EMT both in vitro and in vivo.

Abstract Background: Glioblastoma is a frequently encountered central nervous system malignancy. Calycosin, a bioactive compound extracted from dried Radix astragali root has exhibited anticancer activity across several different types of cancers, including glioma, but the therapeutic mode of action has yet to be clarified. One ubiquitous inflammatory chemokine implicated in cancer biology is the C-X-C chemokine ligand 10 (CXCL10). The current study seeks to investigate CXCL10 as a likely calycosin target in aiding its inhibitory effects on glioblastoma progression.Method: The clinical significance of CXCL10 including pathologic grade and survival rate in GBM patients were accessed from TCGA database and our clinical samples. CCK-8 experiments and clone formation assay were performed to detect the cell proliferation. Transwell assay was conducted to examined cell migration and invasion. Western blotting and immunofluorescence staining was used to analyze protein expression levels. Xenograft mouse model was used to evaluate the effect of CA in vivo. Results: Firstly, we demonstrated that CXCL10 expression is positively associated with glioma and correlated negatively to patient prognosis, supporting our hypothesis that CXCL10 was a potential target for GBM treatment. Additionally, U251 and U87 glioma cell lines were found to demonstrate inhibited invasive, migratory and proliferative abilities upon exposure to calycosin. Calycosin was then found to downregulate CXCL10 expression in a manner that increased with increasing doses, resulting in reduced downstream inflammatory cytokines including NLRP3, NF-κB, IL-1β. Moreover, we demonstrated that overexpressing CXCL10 abolished the inhibitory impact of calycosin on cellular invasion, migration and proliferation in glioma cell lines. Meanwhile, CXCL10 knockdown enhanced calycosin effects on GBM cells. We also used in vivo xenograft mice models to determine the impact of calycosin on glioma growth and obtained results similar to our in vitro experiments.Conclusions: The current investigation underscores the role of CXCL10 as a promising therapeutic target for treating GBM, with calycosin functioning as a future treatment modality.

Histone deacetylase 6 (HDAC6) activity contributes to the malignant proliferation, invasion, and migration of glioma cells (GCs), but the molecular mechanisms underlying the processes remains elusive. Here, we reported that HDAC6 inhibition by Ricolinostat (ACY-1215) or CAY10603 led to a remarkable decrease in the phosphorylation of c-Jun N-terminal kinase (JNK) and c-Jun, which preceded its suppressive effects on glioma cell growth. Further investigation showed that these effects resulted from HDAC6 inhibitor-induced suppression of MAPK kinase 7 (MKK7), which was identified to be critical for JNK activation and exerts the oncogenic roles in GCs. Selectively silencing HDAC6 by siRNAs had the same responses, whereas transient transfections expressing HDAC6 promoted MKK7 expression. Interestingly, by performing Q-PCR, HDAC6 inhibition did not cause a down-regulation of MKK7 mRNA level, whereas the suppressive effects on MKK7 protein can be efficiently blocked by the proteasomal inhibitor MG132. As a further test, elevating MKK7-JNK activity was sufficient to rescue HDAC6 inhibitor-mediated-suppressive effects on c-Jun activation and the malignant features. The suppression of both MKK7 expression and JNK/c-Jun activities was involved in the tumor-growth inhibitory effects induced by CAY10603 in U87-xenograft mice. Collectively, our findings provide new insights into the molecular mechanism of glioma malignancy regarding HDAC6 in the selective regulation of MKK7 expression and JNK/c-Jun activity. MKK7 protein stability critically depends on HDAC6 activity, and inhibition of HDAC6 probably presents a potential strategy for suppressing the oncogenic roles of MKK7/JNK/c-Jun axis in GCs.

Objective To investigate the expression of phospho-c-Jun and MKK7 in gliomas and their correlation. Methods We collected and analyzed retrospectively 92 cases of gliomas, including 15 cases of diffuse astrocytoma, 5 cases of oligodendroglioma, 11 cases of anaplastic astrocytoma, 8 cases of anaplastic oligodendroglioma 53 cases of glioblastoma and 25 normal brain tissues adjacent to glioblastoma. The expression of c-Jun, phospho-c-Jun and MKK7 were detected by immunohistochemical staining. Glioma U87 cell line cultured in vitro was transfected with MKK4-siRNA, MKK7-siRNA and control siRNA for 48h, respectively. Western blot was performed to test the expression of c-Jun, phospho-c-Jun and MKK7. Results The expression of p-c-Jun and MKK7 in glioblastoma were significantly higher than those in other glioma and normal brain tissues adjacent to glioblastomas(P=0.000, P=0.000). The expression of MKK7 and phospho-c-Jun were positively correlated with WHO grading of gliomas (r＝0.494, P＝0.000; r=0.606, P=0.000). There was positive correlation between the expression of MKK7 and p-c-Jun (r=0.387, P=0.000). The knockdown of MKK7 suppressed c-Jun activities. Conclusion MKK7 promotes the development of glioblastoma by regulating the activity of c-Jun.