SEC61G assists EGFR-amplified glioblastoma to evade immune elimination.

Amplification of chromosome 7p11 (7p11) is the most common alteration in primary glioblastoma (GBM), resulting in gains of epidermal growth factor receptor (EGFR) copy number in 50 to 60% of GBM tumors. However, treatment strategies targeting EGFR have thus far failed in clinical trials, and the underlying mechanism remains largely unclear. We here demonstrate that EGFR amplification at the 7p11 locus frequently encompasses its neighboring genes and identifies SEC61G as a critical regulator facilitating GBM immune evasion and tumor growth. We found that SEC61G is always coamplified with EGFR and is highly expressed in GBM. As an essential subunit of the SEC61 translocon complex, SEC61G promotes translocation of newly translated immune checkpoint ligands (ICLs, including PD-L1, PVR, and PD-L2) into the endoplasmic reticulum and promotes their glycosylation, stabilization, and membrane presentation. Depletion of SEC61G promotes the infiltration and cytolytic activity of CD8+ T cells and thus inhibits GBM occurrence. Further, SEC61G inhibition augments the therapeutic efficiency of EGFR tyrosine kinase inhibitors in mice. Our study demonstrates a critical role of SEC61G in GBM immune evasion, which provides a compelling rationale for combination therapy of EGFR-amplified GBMs.

Wnt-induced deubiquitination FoxM1 ensures nucleus ß-catenin transactivation.

A key step of Wnt signaling activation is the recruitment of ß-catenin to the Wnt target-gene promoter in the nucleus, but its mechanisms are largely unknown. Here, we identified FoxM1 as a novel target of Wnt signaling, which is essential for ß-catenin/TCF4 transactivation. GSK3 phosphorylates FoxM1 on serine 474 which induces FoxM1 ubiquitination mediated by FBXW7. Wnt signaling activation inhibits FoxM1 phosphorylation by GSK3-Axin complex and leads to interaction between FoxM1 and deubiquitinating enzyme USP5, thereby deubiquitination and stabilization of FoxM1. FoxM1 accumulation in the nucleus promotes recruitment of ß-catenin to Wnt target-gene promoter and activates the Wnt signaling pathway by protecting the ß-catenin/TCF4 complex from ICAT inhibition. Subsequently, the USP5-FoxM1 axis abolishes the inhibitory effect of ICAT and is required for Wnt-mediated tumor cell proliferation. Therefore, Wnt-induced deubiquitination of FoxM1 represents a novel and critical mechanism for controlling canonical Wnt signaling and cell proliferation.

Gli1-induced deubiquitinase USP48 aids glioblastoma tumorigenesis by stabilizing Gli1.

Aberrant activation of the Hedgehog (Hh) signaling pathway drives the tumorigenesis of multiple cancers. In this study, we screened a panel of deubiquitinases that may regulate the Hh pathway. We find that deubiquitinase USP48 activates Gli-dependent transcription by stabilizing Gli1 protein. Mechanistically, USP48 interacts with Gli1 and cleaves its ubiquitin off directly. In glioblastoma cells, knockdown of USP48 inhibits cell proliferation and the expression of Gli1's downstream targets, which leads to repressed glioblastoma tumorigenesis. Importantly, USP48's effect on cell proliferation and tumorigenesis depends to some extent on Gli1. In addition, we find that the Sonic Hedgehog (SHH) pathway induces USP48 expression through Gli1-mediated transcriptional activation, which forms thus a positive feedback loop to regulate Hh signaling. In human glioblastoma specimens, the expression levels of USP48 and Gli1 proteins are clinically relevant, and high expression of USP48 correlates with glioma malignancy. In summary, our study reveals that the USP48-Gli1 regulatory axis is critical for glioma cell proliferation and glioblastoma tumorigenesis.

Forkhead Box M1 Is Essential for Nuclear Localization of Glioma-associated Oncogene Homolog 1 in Glioblastoma Multiforme Cells by Promoting Importin-7 Expression.

The transcription factors glioma-associated oncogene homolog 1 (GLI1), a primary marker of Hedgehog pathway activation, and Forkhead box M1 (FOXM1) are aberrantly activated in a wide range of malignancies, including glioma. However, the mechanism of nuclear localization of GLI1 and whether FOXM1 regulates the Hedgehog signaling pathway are poorly understood. Here we found that FOXM1 promotes nuclear import of GLI1 in glioblastoma multiforme cells and thus increases the expression of its target genes. Conversely, knockdown of FOXM1 expression with FOXM1 siRNA abrogated its nuclear import and inhibited the expression of its target genes. Also, genetic deletion of FOXM1 in mouse embryonic fibroblasts abolished nuclear localization of GLI1. We observed that FOXM1 directly binds to the importin-7 (IPO7) promoter and increases its promoter activity. IPO7 interacted with GLI1, leading to enhanced nuclear import of GLI1. Depletion of IPO7 by IPO7 siRNA reduced nuclear accumulation of GLI1. In addition, FOXM1 induced nuclear import of GLI1 by promoting IPO7 expression. Moreover, the FOXM1/IPO7/GLI1 axis promoted cell proliferation, migration, and invasion in vitro. Finally, expression of FOXM1 was markedly correlated with that of GLI1 in human glioblastoma specimens. These data suggest that FOXM1 and GLI1 form a positive feedback loop that contributes to glioblastoma development. Furthermore, our study revealed a mechanism that controls nuclear import of GLI1 in glioblastoma multiforme cells.

The clinical characteristics and treatment for sudden sensorineural hearing loss with vestibular schwannoma.

The aim of this study is to analyze the clinical characteristics and treatment of sudden sensorineural hearing loss (SSNHL) patients with vestibular schwannoma (VS). The clinical features of the VS patients were explored by retrospectively analyzing the clinical data from 542 cases of SSNHL patients between January 2008 and March 2013. There were 10 cases (10 ears) diagnosed with VS in 542 cases of SSNHL patients (10 ears, 1.85 %), 3 males, 7 females, with a range of 28-57 years. Among all the cases, eight patients with abnormal ABR, ten with ear ipsilateral stapedius reflexes which were completely not elicited and seven patients with healthy ear contralateral stapedius reflexes which were completely not elicited. Neuromas were classified by Koos grades according to size (8 of grade I, 1 of grade II, 1 of grade IV). Eight small VS  patients were taken waiting and MRI therapy strategies. Meanwhile, we used glucocorticoid treatment and timely and short-term medication to improve the microcirculation of the inner ear for these patients. And four cases' hearing was improved. Some vestibular schwannomas have SSNHL as initial symptoms, especially the small ones in internal auditory canal. To prevent misdiagnosis or leak-diagnosis, MRI should be performed as a routine test for SSNHL, and ABR is sometimes necessary for SSNHL patients. It is also necessary to give appropriate treatment to protect hearing of the small vestibular schwannoma patients whose first symptoms are diagnosed as SSNHL in acute phase.

Targeting the HSP47-collagen axis inhibits brain metastasis by reversing M2 microglial polarization and restoring anti-tumor immunity.

Brain metastases (BrMs) are the leading cause of death in patients with solid cancers. BrMs exhibit a highly immunosuppressive milieu and poor response to immunotherapies; however, the underlying mechanism remains largely unclear. Here, we show that upregulation of HSP47 in tumor cells drives metastatic colonization and outgrowth in the brain by creating an immunosuppressive microenvironment. HSP47-mediated collagen deposition in the metastatic niche promotes microglial polarization to the M2 phenotype via the α2ß1 integrin/nuclear factor κB pathway, which upregulates the anti-inflammatory cytokines and represses CD8+ T cell anti-tumor responses. Depletion of microglia reverses HSP47-induced inactivation of CD8+ T cells and abolishes BrM. Col003, an inhibitor disrupting HSP47-collagen association restores an anti-tumor immunity and enhances the efficacy of anti-PD-L1 immunotherapy in BrM-bearing mice. Our study supports that HSP47 is a critical determinant of M2 microglial polarization and immunosuppression and that blocking the HSP47-collagen axis represents a promising therapeutic strategy against brain metastatic tumors.

Nasopharyngeal angiofibroma: a concise classification system and appropriate treatment options.

OBJECTIVES: To describe a clear and simplified classification system for juvenile nasopharyngeal angiofibroma (JNA), and to describe suitable management options. STUDY DESIGN: Retrospective medical record review. METHODS: The clinical and imaging materials of 51 cases of JNA diagnosed at our hospital between 1981 and 2011 were collected and studied. Based on our experiences, we prefer to divide JNAs into three types. Type I includes JNAs fundamentally localized to the nasal cavity, paranasal sinus, nasopharynx, or pterygopalatine fossa. Type II is a JNA extending into the infratemporal fossa, cheek region, or orbital cavity, with anterior and/or minimal middle cranial fossa extension but intact dura mater. Type III is a calabash-like massive tumor lobe in the middle cranial fossa. The management and prognosis for the three types of JNA were compared and evaluated. RESULTS: Among cases of type I JNA (n=16), the entire mass was removed by the initial operation in 15 cases and by a repeat operation in 1 case. Among cases of type II JNA (n=29), the entire mass was removed by the first operation in 24 cases and by repeat operation in 5 cases. In cases of type III JNA (n=6), the huge calabash-like lobe in the middle cranial fossa could not be completely excised; 4 cases underwent radiotherapy and 2 cases were lost to follow-up. CONCLUSIONS: 1) The transnasal cavity approach with endoscopic guidance is suitable for type I JNA resection. 2) The transantral-infratemporal fossa-nasal cavity combined approach is reliable for resection of a type II JNA, which extends into the deep anterior cranial fossa and/or minimally into the middle cranial fossa, with intact dura mater. 3) The complete removal of a type III JNA is difficult, even through a combined extracranial and intracranial approach. Radiotherapy is useful for treating the residual intracranial tumor. The successful or failed experiences of 6 typical cases prove that this revised classification system is reasonable and reliable.

Isolation and identification of phytate-degrading rhizobacteria with activity of improving growth of poplar and Masson pine.

A number of soil microorganisms can convert insoluble forms of phosphorus (P) to an accessible form to increase plant yields. Phytate is such a large kind of insoluble organic phosphorus that plants cannot absorb directly in soil, so the objectives of this study were to isolate, screen phytate-degrading rhizobacteria (PDRB), and to select potential microbial inocula that could increase the P uptake by plants. In this study, a total of 24 soil samples were collected from natural habitats of eight poplar and pine planting areas from the eastern to southern China. 17 PDRB strains were preliminarily screened from the rhizosphere soil of poplars and pines by the visible decolorization in the phytate selective medium. The highest ratio of the total diameter (colony + halo zone) to the colony diameter of the isolates was JZ-GX1, 3.85. Afterward, 17 PDRB strains were further determined for their abilities to degrade sodium phytate based on the amount of liberated inorganic P in liquid phytate specific medium. The results showed that the phytase ability of the three highest PDRB strains: JZ-GX1, JZ-DZ1 and JZ-ZJ1 were up to 2.58, 2.36 and 2.24 U/mL, respectively, much better than most of the bacteria reported in previous studies. In the soil-plant experiment, compared to CK, the best three strains of PDRB all could significantly promote growth of poplar and Masson pine under container growing. The three efficient PDRB strains were identified as follow: JZ-GX1, Rahnella aquatilis, both JZ-DZ1 and JZ-ZJ1 being autofluorescent, Pseudomonas fluorescens, by 16S rDNA gene sequencing technology, Biolog Identification System and biological characterization. The present study suggests that the three screened PDRB strains would have great potential application as biological fertilizers in the future.

Prognostic value of cell-free DNA in cerebrospinal fluid from lung cancer patients with brain metastases during radiotherapy.

BACKGROUND: During the last decades, radiotherapy (RT) for non-small cell lung cancer (NSCLC) with brain metastases (BM) has been developed. However, the lack of predictive biomarkers for therapeutic responses has limited the precision treatment in NSCLC-BM. PATIENTS AND METHODS: In order to find the predictive biomarkers for RT, we investigated the influence of RT on the cell-free DNA (cfDNA) from cerebrospinal fluid (CSF) and the frequency of T cell subsets of NSCLC patients with BM. A total of 19 patients diagnosed as NSCLC with BM were enrolled. The CSF from 19 patients and matched plasma samples from 11 patients were collected before RT, during RT, and after RT. The cfDNA from CSF and plasma were extracted, and the cerebrospinal fluid tumor mutation burden (cTMB) was calculated after through next-generation sequencing. The frequency of T cell subsets in peripheral blood was using flow cytometry. RESULTS: The detection rate of cfDNA was higher in CSF compared to plasma in the matched samples. The mutation abundance of cfDNA in CSF was decreased after RT. However, no significant difference was observed in cTMB before and after RT. Although the median intracranial progression-free survival (iPFS) has not yet been reached in patients with decreased or undetectable cTMB, there was a trend that these patients possessed longer iPFS compared to those with stable or increased cTMB (HR 0.28, 95% CI 0.07-1.18, P = 0.067). The proportion of CD4+T cells in peripheral blood was decreased after RT. CONCLUSION: Our study indicates that cTMB can serve as a prognostic biomarker in NSCLC patients with BMs.

FBXO7 Confers Mesenchymal Properties and Chemoresistance in Glioblastoma by Controlling Rbfox2-Mediated Alternative Splicing.

Mesenchymal glioblastoma (GBM) is highly resistant to radio-and chemotherapy and correlates with worse survival outcomes in GBM patients; however, the underlying mechanism determining the mesenchymal phenotype remains largely unclear. Herein, it is revealed that FBXO7, a substrate-recognition component of the SCF complex implicated in the pathogenesis of Parkinson's disease, confers mesenchymal properties and chemoresistance in GBM by controlling Rbfox2-mediated alternative splicing. Specifically, FBXO7 ubiquitinates Rbfox2 Lys249 through K63-linked ubiquitin chains upon arginine dimethylation at Arg341 and Arg441 by PRMT5, leading to Rbfox2 stabilization. FBXO7 controls Rbfox2-mediated splicing of mesenchymal genes, including FoxM1, Mta1, and Postn. FBXO7-induced exon Va inclusion of FoxM1 promotes FoxM1 phosphorylation by MEK1 and nuclear translocation, thereby upregulates CD44, CD9, and ID1 levels, resulting in GBM stem cell self-renewal and mesenchymal transformation. Moreover, FBXO7 is stabilized by temozolomide, and FBXO7 depletion sensitizes tumor xenografts in mice to chemotherapy. The findings demonstrate that the FBXO7-Rbfox2 axis-mediated splicing contributes to mesenchymal transformation and tumorigenesis, and targeting FBXO7 represents a potential strategy for GBM treatment.

miR-125b, a target of CDX2, regulates cell differentiation through repression of the core binding factor in hematopoietic malignancies.

MicroRNA-125b (miR-125b), a small noncoding RNA molecule, has been found to be deregulated and functions as an oncogene in many cancers including hematopoietic malignancies. However, the mechanisms accounting for miR-125b dysregulation remain to be elucidated. The present study aims to identify the factors that might contribute to up-regulation of miR-125b in human hematopoietic malignancies and its downstream targets for lineage-specific differentiation. We at first reported that CDX2, a homeobox transcription factor, binds to promoter regions of the miR-125b gene and activates transcriptional regulation of miR-125b in malignant myeloid cells. We further revealed that increasing levels of CDX2 in malignant myeloid cells activate miR-125b expression, which in turn inhibits core binding factor ß (CBFß) translation, thereby counteracting myeloid cell differentiation, at least for granulocytic lineage, and promoting leukemogenesis. Interestingly, we found that this novel pathway including CDX2, miR-125b, and CBFß was mediated by undergoing all-trans-retinoic acid induction. Once differentiation ensues with all-trans-retinoic acid treatment, CDX2 activity decreases, leading to a reduction in miR-125b transcription and up-regulation of CBFß in myeloid cells and in patients. The study provides a new mechanism that contributes to hematopoietic malignancies, which could involve deregulation of miR-125b and its up- and downstream factors. As altered expression of miRNAs has been reported in a wide range of malignancies, delineating the underlying molecular mechanisms of aberrant miRNA expression and characterizing the upstream and downstream factors will help to understand important steps in the pathogenesis of these afflictions.

Derepression of the USP22-FASN axis by p53 loss under oxidative stress drives lipogenesis and tumorigenesis.

Overproduction of reactive oxygen species (ROS) and aberrant lipid metabolism are established hallmarks of cancer; however, the role of ROS in lipid synthesis during tumorigenesis is almost unknown. Herein, we show that ROS regulates lipid synthesis and thus controls colorectal tumorigenesis through a p53-dependent mechanism. In p53 wild-type colorectal cancer (CRC) cells, hydrogen peroxide (H2O2)-induced p53 expression represses the transcription of deubiquitinase USP22, which otherwise deubiquitinates and stabilizes Fatty Acid Synthase (FASN), and thus inhibits fatty acid synthesis. Whereas, in p53-deficient CRC cells, ROS-mediated inhibition of USP22 is relieved, leading to FASN stabilization, which thus promotes lipid synthesis and tumor growth. In human CRC specimens, USP22 expression is positively correlated with FASN expression. Our study demonstrates that ROS critically regulates lipid synthesis and tumorigenesis through the USP22-FASN axis in a p53-dependent manner, and targeting the USP22-FASN axis may represent a potential strategy for the treatment of colorectal cancer.

Critical role of lncEPAT in coupling dysregulated EGFR pathway and histone H2A deubiquitination during glioblastoma tumorigenesis.

Histone 2A (H2A) monoubiquitination is a fundamental epigenetics mechanism of gene expression, which plays a critical role in regulating cell fate. However, it is unknown if H2A ubiquitination is involved in EGFR-driven tumorigenesis. In the current study, we have characterized a previously unidentified oncogenic lncRNA (lncEPAT) that mediates the integration of the dysregulated EGFR pathway with H2A deubiquitination in tumorigenesis. LncEPAT was induced by the EGFR pathway, and high-level lncEPAT expression positively correlated with the glioma grade and predicted poor survival of glioma patients. Mass spectrometry analyses revealed that lncEPAT specifically interacted with deubiquitinase USP16. LncEPAT inhibited USP16's recruitment to chromatin, thereby blocking USP16-mediated H2A deubiquitination and repressing target gene expression, including CDKN1A and CLUSTERIN. Depletion of lncEPAT promoted USP16-induced cell cycle arrest and cellular senescence, and then repressed GBM cell tumorigenesis. Thus, the EGFR-lncEPAT-ubH2A coupling represents a previously unidentified mechanism for epigenetic gene regulation and senescence resistance during GBM tumorigenesis.

Optimization of cancer immunotherapy through pyroptosis: A pyroptosis-related signature predicts survival benefit and potential synergy for immunotherapy in glioma.

Background: Pyroptosis is a critical type of programmed cell death that is strongly associated with the regulation of tumor and immune cell functions. However, the role of pyroptosis in tumor progression and remodeling of the tumor microenvironment in gliomas has not been extensively studied. Thus, in this study, we aimed to establish a comprehensive pyroptosis-related signature and uncover its potential clinical application in gliomas. Methods: The TCGA glioma cohort was obtained and divided into training and internal validation cohorts, while the CGGA glioma cohort was used as an external validation cohort. Unsupervised consensus clustering was performed to identify pyroptosis-related expression patterns. A Cox regression analysis was performed to establish a pyroptosis-related risk signature. Real-time quantitative PCR was performed to analyze the expression of signature genes in glioma tissues. Immune infiltration was analyzed and validated by immunohistochemical staining. The expression patterns of signature genes in different cell types were analyzed using single-cell RNA sequencing data. Finally, therapeutic responses to chemotherapy, immunotherapy, and potential small-molecule inhibitors were investigated. Results: Patients with glioma were stratified into clusters 1 and 2 based on the expression patterns of pyroptosis-related genes. Cluster 2 showed a longer overall (P<0.001) and progression-free survival time (P<0.001) than Cluster 1. CD8+ T cell enrichment was observed in Cluster 1. A pyroptosis-related risk signature (PRRS) was then established. The high PRRS group showed a significantly poorer prognosis than the low PRRS group in the training cohort (P<0.001), with validation in the internal and external validation cohorts. Immunohistochemical staining demonstrated that CD8+ T cells were enriched in high PRRS glioma tissues. PRRS genes also showed cell-specific expression in tumor and immune cells. Moreover, the high PRRS risk group showed higher temozolomide sensitivity and increased response to anti-PD1 treatment in a glioblastoma immunotherapy cohort. Finally, Bcl-2 inhibitors were screened as candidates for adjunct immunotherapy of gliomas. Conclusion: The pyroptosis-related signature established in this study can be used to reliably predict clinical outcomes and immunotherapy responses in glioma patients. The correlation between the pyroptosis signature and the tumor immune microenvironment may be used to further guide the sensitization of glioma patients to immunotherapy.

Relaxed initiation pausing of ribosomes drives oncogenic translation.

Translation is a crucial process in cancer development and progression. Many oncogenic signaling pathways target the translation initiation stage to satisfy the increased anabolic demands of cancer cells. Using quantitative profiling of initiating ribosomes, we found that ribosomal pausing at the start codon serves as a "brake" to restrain the translational output. In response to oncogenic RAS signaling, the initiation pausing relaxes and contributes to the increased translational flux. Intriguingly, messenger RNA (mRNA) m6A modification in the vicinity of start codons influences the behavior of initiating ribosomes. Under oncogenic RAS signaling, the reduced mRNA methylation leads to relaxed initiation pausing, thereby promoting malignant transformation and tumor growth. Restored initiation pausing by inhibiting m6A demethylases suppresses RAS-mediated oncogenic translation and subsequent tumorigenesis. Our findings unveil a paradigm of translational control that is co-opted by RAS mutant cancer cells to drive malignant phenotypes.

Functional characterization of the promoter region of human TNFAIP1 gene.

Tumor necrosis factor, alpha-induced protein 1 (TNFAIP1) is an immediate-early response gene of endothelium induced by TNF alpha. However, little is really known concerning the TNFAIP1 expression regulation. To better understand how TNFAIP1 expression is regulated, we functionally characterized the promoter region of human TNFAIP1 gene. Deletion mutation analysis, gel electrophoretic mobility shift, and site-directed mutagenesis assays allowed the identification of one functional Sp1-binding site within the human TNFAIP1 core promoter region. Moreover, chromatin immunoprecipitation analysis indicated that Sp1 was associated in vivo with the TNFAIP1 promoter. Further, Sp1 overexpression enhanced TNFAIP1 promoter activity. These findings suggest that Sp1 is implicated in the control of basal TNFAIP1 gene expression. Accordingly, Sp1 is supposed to be involved in the elevation of TNFAIP1 in response to TNF alpha induction, and thus participate in inflammation-associated angiogenesis.

Thermodynamic and Kinetic Study on the Catalysis of Isoamyl Acetate by a Cation-Exchange Resin in an Intensified Fixed-Bed Reactor.

Kinetics and thermodynamics of esterification by a cation-exchange resin in an intensified fixed-bed reactor was studied systematically. The resin type, catalyst loading, volume flow rate, initial molar ratio, temperature, and catalyst reusability were studied and optimized. The nonideality of the reaction system was corrected by the UNIFAC group contribution method. The Δr H 0, Δr S 0, and Δr G 0 of the reaction were acquired by two methods. The pseudo-homogeneous (PH) model and the Langmuir-Hinshelwood-Hougen-Watson (LHHW) model were adopted to simulate the kinetic process. The result indicated that the LHHW model was better suited to simulate the kinetic process than the PH model.

Wnt-Induced Stabilization of KDM4C Is Required for Wnt/ß-Catenin Target Gene Expression and Glioblastoma Tumorigenesis.

Wnt/ß-catenin signaling activates the transcription of target genes to regulate stem cells and cancer development. However, the contribution of epigenetic regulation to this process is unknown. Here, we report that Wnt activation stabilizes the epigenetic regulator KDM4C that promotes tumorigenesis and survival of human glioblastoma cells by epigenetically activating the transcription of Wnt target genes. KDM4C protein expression was upregulated in human glioblastomas, and its expression directly correlated with Wnt activity and Wnt target gene expression. KDM4C was essential for Wnt-induced gene expression and tumorigenesis of glioblastoma cells. In the absence of Wnt3a, protein kinase R phosphorylated KDM4C at Ser918, inducing KDM4C ubiquitination and degradation. Wnt3a stabilized KDM4C through inhibition of GSK3-dependent protein kinase R activity. Stabilized KDM4C accumulated in the nucleus and bound to and demethylated TCF4-associated histone H3K9 by interacting with ß-catenin, promoting HP1γ removal and transcriptional activation. These findings reveal that Wnt-KDM4C-ß-catenin signaling represents a novel mechanism for the transcription of Wnt target genes and regulation of tumorigenesis, with important clinical implications. SIGNIFICANCE: These findings identify the Wnt-KDM4C-ß-catenin signaling axis as a critical mechanism for glioma tumorigenesis that may serve as a new therapeutic target in glioblastoma.

Kinetic Study on Esterification of Acetic Acid with Isopropyl Alcohol Catalyzed by Ion Exchange Resin.

Esterification kinetics on acetic acid with isopropyl alcohol was studied in an intensified fixed bed reactor at 333-353 K with Amberlyst 36 Wet. The effects of volume flow rate, molar ratio of reactants, catalyst loading, and operating temperature were investigated and optimized. The method of UNIFAC was applied to calculate the activity coefficient of each component for correcting the nonideality of the solution. Reaction enthalpy, entropy, and Gibbs free energy were calculated in different cases. The pseudohomogeneous model, Eley-Rideal model, and Langmuir-Hinshelwood-Hougen-Watson model were used to establish kinetic equations of the reaction conducted in the IFBR. It was proved that the LHHW model can accurately describe the esterification kinetics in the intensified fixed bed reactor.

Aberrant Activation of ß-Catenin Signaling Drives Glioma Tumorigenesis via USP1-Mediated Stabilization of EZH2.

Aberrant activation of ß-catenin signaling is a critical driver for tumorigenesis, but the mechanism underlying this activation is not completely understood. In this study, we demonstrate a critical role of ß-catenin signaling in stabilization of enhancer of zeste homolog 2 (EZH2) and control of EZH2-mediated gene repression in oncogenesis. ß-Catenin/TCF4 activated the transcription of the deubiquitinase USP1, which then interacted with and deubiquitinated EZH2 directly. USP1-mediated stabilization of EZH2 promoted its recruitment to the promoters of CDKN1B, RUNX3, and HOXA5, resulting in enhanced enrichment of histone H3K27me3 and repression of target gene expression. In human glioma specimens, expression levels of nuclear ß-catenin, USP1, and EZH2 correlated with one another. Depletion of ß-catenin/USP1/EZH2 repressed glioma cell proliferation in vitro and tumor formation in vivo. Our findings indicate that a ß-catenin-USP1-EZH2 axis orchestrates the interplay between dysregulated ß-catenin signaling and EZH2-mediated gene epigenetic silencing during glioma tumorigenesis. SIGNIFICANCE: These findings identify the ß-catenin-USP1-EZH2 signaling axis as a critical mechanism for glioma tumorigenesis that may serve as a new therapeutic target in glioblastoma.