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The gut microbiota and liver cancer have a complex interaction. However, the role of gut microbiome in liver tumor initiation remains unknown. Herein, liver cancer was induced using hydrodynamic transfection of oncogenes to explore liver tumorigenesis in mice. Gut microbiota depletion promoted liver tumorigenesis but not progression. Elevated sterol regulatory element-binding protein 2 (SREBP2) was observed in mice with gut flora disequilibrium. Pharmacological inhibition of SREBP2 or Srebf2 RNA interference attenuated mouse liver cancer initiation under gut flora disequilibrium. Furthermore, gut microbiota depletion impaired gut tryptophan metabolism to activate aryl hydrocarbon receptor (AhR). AhR agonist Ficz inhibited SREBP2 posttranslationally and reversed the tumorigenesis in mice. And, AhR knockout mice recapitulated the accelerated liver tumorigenesis. Supplementation with Lactobacillus reuteri, which produces tryptophan metabolites, inhibited SREBP2 expression and tumorigenesis in mice with gut flora disequilibrium. Thus, gut flora disequilibrium promotes liver cancer initiation by modulating tryptophan metabolism and up-regulating SREBP2.
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Disbiosis , Microbioma Gastrointestinal , Neoplasias Hepáticas , Proteína 2 de Unión a Elementos Reguladores de Esteroles , Animales , Ratones , Carcinogénesis , Neoplasias Hepáticas/metabolismo , Receptores de Hidrocarburo de Aril/metabolismo , Proteína 2 de Unión a Elementos Reguladores de Esteroles/metabolismo , Triptófano/metabolismo , Disbiosis/complicacionesRESUMEN
Pancreatic ductal adenocarcinoma (PDAC) is not sensitive to immune checkpoint blockade therapy, and negative feedback of tumor immune evasion might be partly responsible. We isolated CD8+ T cells and cultured them in vitro. Proteomics analysis was performed to compare changes in Panc02 cell lines cultured with conditioned medium, and leucine-rich repeat kinase 2 (LRRK2) was identified as a differential gene. LRRK2 expression was related to CD8+ T cell spatial distribution in PDAC clinical samples and upregulated by CD8+ T cells via interferon gamma (IFN-γ) simulation in vitro. Knockdown or pharmacological inhibition of LRRK2 activated an anti-pancreatic cancer immune response in mice, which meant that LRRK2 acted as an immunosuppressive gene. Mechanistically, LRRK2 phosphorylated PD-L1 at T210 to inhibit its ubiquitination-mediated proteasomal degradation. LRRK2 inhibition attenuated PD-1/PD-L1 blockade-mediated, T cell-induced upregulation of LRRK2/PD-L1, thus sensitizing the mice to anti-PD-L1 therapy. In addition, adenosylcobalamin, the activated form of vitamin B12, which was found to be a broad-spectrum inhibitor of LRRK2, could inhibit LRRK2 in vivo and sensitize PDAC to immunotherapy as well, which potentially endows LRRK2 inhibition with clinical translational value. Therefore, PD-L1 blockade combined with LRRK2 inhibition could be a novel therapy strategy for PDAC.
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The novel coronavirus disease (COVID-19) pandemic remains a global public health crisis, presenting a broad range of challenges. To help address some of the main problems, the scientific community has designed vaccines, diagnostic tools and therapeutics for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The rapid pace of technology development, especially with regard to vaccines, represents a stunning and historic scientific achievement. Nevertheless, many challenges remain to be overcome, such as improving vaccine and drug treatment efficacies for emergent mutant strains of SARS-CoV-2. Outbreaks of more infectious variants continue to diminish the utility of available vaccines and drugs. Thus, the effectiveness of vaccines and drugs against the most current variants is a primary consideration in the continual analyses of clinical data that supports updated regulatory decisions. The first two vaccines granted Emergency Use Authorizations (EUAs), BNT162b2 and mRNA-1273, still show more than 60% protection efficacy against the most widespread current SARS-CoV-2 variant, Omicron. This variant carries more than 30 mutations in the spike protein, which has largely abrogated the neutralizing effects of therapeutic antibodies. Fortunately, some neutralizing antibodies and antiviral COVID-19 drugs treatments have shown continued clinical benefits. In this review, we provide a framework for understanding the ongoing development efforts for different types of vaccines and therapeutics, including small molecule and antibody drugs. The ripple effects of newly emergent variants, including updates to vaccines and drug repurposing efforts, are summarized. In addition, we summarize the clinical trials supporting the development and distribution of vaccines, small molecule drugs, and therapeutic antibodies with broad-spectrum activity against SARS-CoV-2 strains.
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Tratamiento Farmacológico de COVID-19 , COVID-19 , Vacunas Virales , Antivirales/farmacología , Antivirales/uso terapéutico , Vacuna BNT162 , COVID-19/prevención & control , Humanos , SARS-CoV-2 , Vacunas Virales/uso terapéuticoRESUMEN
The chromatographic fingerprint of 14 batches of Artemisia rupestris L. samples were established in this study. The constituents of ten components in Artemisia rupestris L. were determined using quantitative analysis of multi-components by single marker (QAMS) and the external standard method (ESM). Due to their stability and accessibility, chlorogenic acid and linarin were used as references to calculate the relative correction factors (RCFs) of apigenin-C-6,8-pentoside-hexoside, apigenin-C-6,8-di-pentoside, luteolin, 3,4-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid, 4,5-dicaffeoylquinic acid, chrysosplenetin B, and sbsinthin, based on high-performance liquid chromatography (HPLC). The value calculated by QAMS was consistent with that of the ESM, and the reproducibility of RCFs was found to be reliable. In conclusion, simultaneous determination of the ten components by the QAMS method and chromatographic fingerprint analysis were feasible and accurate in evaluating the quality of Artemisia rupestris L. and can be used as reference in traditional Chinese medicine quality control.
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Artemisia , Medicamentos Herbarios Chinos , Apigenina/análisis , Cromatografía Líquida de Alta Presión/métodos , Medicamentos Herbarios Chinos/química , Reproducibilidad de los ResultadosRESUMEN
The Mixed Lineage Leukemia protein 1 (MLL1) plays an essential role in the maintenance of the histone H3 lysine 4 (H3K4) methylation status for gene expression during differentiation and development. The methyltransferase activity of MLL1 is regulated by three conserved core subunits, WDR5, RBBP5 and ASH2L. Here, we determined the structure of human RBBP5 and demonstrated its role in the assembly and regulation of the MLL1 complex. We identified an internal interaction between the WD40 propeller and the C-terminal distal region in RBBP5, which assisted the maintenance of the compact conformation of the MLL1 complex. We also discovered a vertebrate-specific motif in the C-terminal distal region of RBBP5 that contributed to nucleosome recognition and methylation of nucleosomes by the MLL1 complex. Our results provide new insights into functional conservation and evolutionary plasticity of the scaffold protein RBBP5 in the regulation of KMT2-family methyltransferase complexes.
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Proteínas de Unión al ADN/ultraestructura , N-Metiltransferasa de Histona-Lisina/ultraestructura , Complejos Multiproteicos/ultraestructura , Proteína de la Leucemia Mieloide-Linfoide/ultraestructura , Factores de Transcripción/genética , Diferenciación Celular/genética , Proteínas de Unión al ADN/química , Proteínas de Unión al ADN/genética , N-Metiltransferasa de Histona-Lisina/química , N-Metiltransferasa de Histona-Lisina/genética , Histonas/genética , Humanos , Péptidos y Proteínas de Señalización Intracelular , Conformación Molecular , Complejos Multiproteicos/química , Complejos Multiproteicos/genética , Proteína de la Leucemia Mieloide-Linfoide/química , Proteína de la Leucemia Mieloide-Linfoide/genética , Proteínas Nucleares/genética , Unión Proteica/genética , Conformación Proteica , Dominios y Motivos de Interacción de Proteínas/genética , Factores de Transcripción/químicaRESUMEN
In an effort to develop new cancer therapeutics, we have reported clinical candidate BPR1K871 (1) as a potentanticancercompound in MOLM-13 and MV4-11 leukemia models, as well as in colorectal and pancreatic animal models. As BPR1K871 lacks oral bioavailability, we continued searching for orally bioavailable analogs through drug-like property optimization. We optimized both the physicochemical properties (PCP) as well as in vitro rat liver microsomal stability of 1, with concomitant monitoring of aurora kinase enzyme inhibition as well as cellular anti-proliferative activity in HCT-116 cell line. Structural modification at the 6- and 7-position of quinazoline core of 1 led to the identification of 34 as an orally bioavailable (F% = 54) multi-kinase inhibitor, which exhibits potent anti-proliferative activity against various cancer cell lines. Quinazoline 34 is selected as a promising oral lead candidate for further preclinical evaluation.
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Antineoplásicos/farmacología , Aurora Quinasas/antagonistas & inhibidores , Descubrimiento de Drogas , Inhibidores de Proteínas Quinasas/farmacología , Quinazolinas/farmacología , Administración Oral , Animales , Antineoplásicos/administración & dosificación , Antineoplásicos/química , Aurora Quinasas/metabolismo , Disponibilidad Biológica , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Células HCT116 , Humanos , Masculino , Estructura Molecular , Inhibidores de Proteínas Quinasas/administración & dosificación , Inhibidores de Proteínas Quinasas/química , Quinazolinas/administración & dosificación , Quinazolinas/química , Ratas , Ratas Sprague-Dawley , Relación Estructura-ActividadRESUMEN
Conidiation capacity and conidial quality are very important for the production and application of mycopesticides. Most filamentous ascomycetous fungi have two distinct patterns of conidiation. Conidiation through microcycle conidiation proceeds to more rapidly achieve a maximum of conidial yield than normal conidiation and hence is of greater merit for exploitation in mass production of fungal insect pathogens, such as Metarhizium acridum. In this study, the mechanism underlying the conidiation pattern shift in M. acridum was explored by characterization of the fungal homeobox gene MaH1. MaH1 was evidently localized to the nuclei of hyphae and transcriptionally expressed at a maximal level when conidiation began. Intriguingly, deletion of MaH1 in M. acridum resulted in a shift of normal conidiation to microcycle conidiation on one-quarter strength Sabouraud's dextrose agar medium, and hence accelerated conidiation and increased conidial yield. In the deletion mutant, moreover, conidia became larger in size and hyphae cells were shorter in length while conidial virulence and stress tolerance were not altered. As revealed by digital gene expression profiling, MaH1 controlled the shift of conidiation patterns by mediating transcription of a set of genes related to hyphal growth, cell differentiation, conidiation, and some important signaling pathways. These findings indicate that MaH1 and its downstream genes can be exploited to increase the conidial yield for more efficient production of mycopesticides.
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Agentes de Control Biológico/metabolismo , Genes Homeobox/genética , Insectos/microbiología , Metarhizium/genética , Metarhizium/metabolismo , Control Biológico de Vectores/métodos , Esporas Fúngicas/crecimiento & desarrollo , Secuencia de Aminoácidos/genética , Animales , Perfilación de la Expresión Génica , Regulación Fúngica de la Expresión Génica/genética , Hifa/crecimiento & desarrollo , Insecticidas/farmacología , Esporas Fúngicas/genéticaRESUMEN
In this study, an enzyme-assisted microwave extraction process was obtained by response surface method of polysaccharide from roots of Rubus crataegifolius Bunge. The optimized extraction process was as follow: enzyme dosage 2â¯%, enzymatic time was 3.6â¯h, enzymatic pHâ¯4.9, and microwave time 4.7â¯min, with the extraction yield of 9.07â¯%. Four homogeneous polysaccharides (RCP-1, RCP-3, RCP-4 and RCP-5) were purified through column chromatography. Four polysaccharides have the relative higher molecular weights of 1.70â¯×â¯106â¯Da, 5.56â¯×â¯106â¯Da, 4.97â¯×â¯106â¯Da, and 9.80â¯×â¯106â¯Da and mainly consisted of GluN, GluA, Glu, Gal and Arab. FT-IR and NMR spectral analysis confirmed that the purified polysaccharides were polypyranose containing α- and ß-glycosidic bonds. RCPâ¯-â¯1 has a relative high crystallinity. Four purified polysaccharides contained triple helical conformations, and have good antioxidant activities. Among the purified polysaccharides, RCPâ¯-â¯1 was found to reduce the oxidative cell damage induced by H2O2 through increasing of cell viability, inhibition of AST and ALT levels, ROS production and cell apoptosis, increasing of the activities of antioxidative enzymes, as well as reduction of MDA content. Our findings would provide a foundation for purified polysaccharides efficient extraction and demonstrated that the polysaccharides from R. crataegifolius roots could be a promising hepatoprotective agent.
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Accumulating evidence suggests that cancer-associated fibroblast (CAF) macroautophagy/autophagy is crucial in tumor development and may be a therapeutic target for pancreatic ductal adenocarcinoma (PDAC). However, the role of CAF autophagy during immune surveillance and cancer immunotherapy is unclear. The present study revealed that the inhibition of CAF autophagy suppresses in vivo tumor development in immune-deficient xenografts. This deletion compromises anti-tumor immunity and anti-tumor efficacy both in vitro and in vivo by upregulating CD274/PDL1 levels in an immune-competent mouse model. A block in CAF autophagy reduced the production of IL6 (interleukin 6), disrupting high desmoplastic TME and decreasing USP14 expression at the transcription level in pancreatic cancer cells. We further identify USP14 as the post-translational factor responsible for downregulating CD274 expression by removing K63 linked-ubiquitination at the K280 residue. Finally, chloroquine diphosphate-loaded mesenchymal stem cell (MSC)-liposomes, by accurately targeting CAFs, inhibited CAF autophagy, improving the efficacy of immunochemotherapy to combat pancreatic cancer.Abbreviation: AIR: adaptive immune resistance; ATRA: all-trans-retinoicacid; CAF: cancer-associated fibroblast; CD274/PDL1: CD274 molecule; CM: conditioned medium; CQ: chloroquine diphosphate; CyTOF: Mass cytometry; FGF2/bFGF: fibroblast growth factor 2; ICB: immune checkpoint blockade; IF: immunofluorescence; IHC: immunohistochemistry; IP: immunoprecipitation; MS: mass spectrometer; MSC: mesenchymal stem cell; PDAC: pancreatic ductal adenocarcinoma; TEM: transmission electron microscopy; TILs: tumor infiltrating lymphocytes; TME: tumor microenvironment; USP14: ubiquitin specific peptidase 14.
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Autofagia , Fibroblastos Asociados al Cáncer , Inmunoterapia , Neoplasias Pancreáticas , Microambiente Tumoral , Autofagia/efectos de los fármacos , Animales , Neoplasias Pancreáticas/patología , Neoplasias Pancreáticas/inmunología , Neoplasias Pancreáticas/tratamiento farmacológico , Fibroblastos Asociados al Cáncer/metabolismo , Fibroblastos Asociados al Cáncer/efectos de los fármacos , Humanos , Ratones , Inmunoterapia/métodos , Microambiente Tumoral/efectos de los fármacos , Línea Celular Tumoral , Inmunidad Adaptativa/efectos de los fármacos , Carcinoma Ductal Pancreático/patología , Carcinoma Ductal Pancreático/inmunología , Carcinoma Ductal Pancreático/tratamiento farmacológico , Antígeno B7-H1/metabolismo , Cloroquina/farmacología , Cloroquina/uso terapéuticoRESUMEN
A series of bifunctional compounds have been discovered for their dual functionality as MER/AXL inhibitors and immune modulators. The furanopyrimidine scaffold, renowned for its suitability in kinase inhibitor discovery, offers at least three distinct pharmacophore access points. Insights from molecular modeling studies guided hit-to-lead optimization, which revealed that the 1,3-diketone side chain hybridized with furanopyrimidine scaffold that respectively combined amino-type substituent and 1H-pyrazol-4-yl substituent on the top and bottom of the aryl regions to produce 22 and 33, exhibiting potent antitumor activities in various syngeneic and xenograft models. More importantly, 33 demonstrated remarkable immune-modulating activity by upregulating the expression of total T-cells, cytotoxic CD8+ T-cells, and helper CD4+ T-cells in the spleen. These findings underscored the bifunctional capabilities of 33 (BPR5K230) with excellent oral bioavailability (F = 54.6%), inhibiting both MER and AXL while modulating the tumor microenvironment and highlighting its diverse applicability for further studies to advance its therapeutic potential.
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Antineoplásicos , Tirosina Quinasa del Receptor Axl , Inhibidores de Proteínas Quinasas , Proteínas Proto-Oncogénicas , Proteínas Tirosina Quinasas Receptoras , Microambiente Tumoral , Tirosina Quinasa c-Mer , Animales , Microambiente Tumoral/efectos de los fármacos , Humanos , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/uso terapéutico , Inhibidores de Proteínas Quinasas/síntesis química , Antineoplásicos/farmacología , Antineoplásicos/química , Antineoplásicos/síntesis química , Antineoplásicos/uso terapéutico , Proteínas Tirosina Quinasas Receptoras/antagonistas & inhibidores , Proteínas Tirosina Quinasas Receptoras/metabolismo , Proteínas Proto-Oncogénicas/antagonistas & inhibidores , Proteínas Proto-Oncogénicas/metabolismo , Tirosina Quinasa c-Mer/antagonistas & inhibidores , Tirosina Quinasa c-Mer/metabolismo , Ratones , Línea Celular Tumoral , Relación Estructura-Actividad , Descubrimiento de Drogas , Bibliotecas de Moléculas Pequeñas/farmacología , Bibliotecas de Moléculas Pequeñas/química , Bibliotecas de Moléculas Pequeñas/síntesis química , Femenino , Ensayos Antitumor por Modelo de Xenoinjerto , Ratones Endogámicos BALB C , Proliferación Celular/efectos de los fármacosRESUMEN
Highly desmoplastic and immunosuppressive tumor microenvironment (TME) in pancreatic ductal adenocarcinoma (PDAC) contributes to tumor progression and resistance to current therapies. Clues targeting the notorious stromal environment have offered hope for improving therapeutic response whereas the underlying mechanism remains unclear. Here, we find that prognostic microfibril associated protein 5 (MFAP5) is involved in activation of cancer-associated fibroblasts (CAFs). Inhibition of MFAP5highCAFs shows synergistic effect with gemcitabine-based chemotherapy and PD-L1-based immunotherapy. Mechanistically, MFAP5 deficiency in CAFs downregulates HAS2 and CXCL10 via MFAP5/RCN2/ERK/STAT1 axis, leading to angiogenesis, hyaluronic acid (HA) and collagens deposition reduction, cytotoxic T cells infiltration, and tumor cells apoptosis. Additionally, in vivo blockade of CXCL10 with AMG487 could partially reverse the pro-tumor effect from MFAP5 overexpression in CAFs and synergize with anti-PD-L1 antibody to enhance the immunotherapeutic effect. Therefore, targeting MFAP5highCAFs might be a potential adjuvant therapy to enhance the immunochemotherapy effect in PDAC via remodeling the desmoplastic and immunosuppressive microenvironment.
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Fibroblastos Asociados al Cáncer , Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Fibroblastos Asociados al Cáncer/metabolismo , Microfibrillas/metabolismo , Microfibrillas/patología , Neoplasias Pancreáticas/tratamiento farmacológico , Neoplasias Pancreáticas/metabolismo , Carcinoma Ductal Pancreático/tratamiento farmacológico , Carcinoma Ductal Pancreático/metabolismo , Proteínas/metabolismo , Inmunoterapia , Microambiente Tumoral , Proteínas de Unión al Calcio/metabolismo , Neoplasias PancreáticasRESUMEN
Programmed death-1 (PD-1) and its ligand programmed death-ligand 1 (PD-L1) help tumor cells evade immune surveillance, and are regarded as important targets of anti-tumor immunotherapy. Post-translational modification of PD-L1 has potential value in immunosuppression. Here, we identified that ubiquitin-specific protease 8 (USP8) deubiquitinates PD-L1. Pancreatic cancer tissues exhibited significantly increased USP8 levels compared with those in normal tissues. Clinically, the expression of USP8 showed a significant association with the tumor-node-metastasis stage in multiple patient-derived cohorts of pancreatic cancer. Meanwhile, USP8 deficiency could reduce tumor invasion and migration and tumor size in an immunity-dependent manner, and improve anti-tumor immunogenicity. USP8 inhibitor pretreatment led to reduced tumorigenesis and immunocompetent mice with Usp8 knockdown tumors exhibited extended survival. Moreover, USP8 interacted positively with PD-L1 and upregulated its expression by inhibiting the ubiquitination-regulated proteasome degradation pathway in pancreatic cancer. Combination therapy with a USP8 inhibitor and anti-PD-L1 effectively suppressed pancreatic tumor growth by activation of cytotoxic T-cells and the anti-tumor immunity was mainly dependent on the PD-L1 pathway and CD8 + T cells. Our findings highlight the importance of targeting USP8, which can sensitize PD-L1-targeted pancreatic cancer to immunotherapy and might represent a novel therapeutic strategy to treat patients with pancreatic tumors in the future.
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Linfocitos T CD8-positivos , Neoplasias Pancreáticas , Animales , Ratones , Inmunoterapia , Neoplasias Pancreáticas/tratamiento farmacológico , Neoplasias Pancreáticas/metabolismo , Proteasas Ubiquitina-Específicas , Neoplasias PancreáticasRESUMEN
The development of orally bioavailable, furanopyrimidine-based double-mutant (L858R/T790M) EGFR inhibitors is described. First, selectivity for mutant EGFR was accomplished by replacing the (S)-2-phenylglycinol moiety of 12 with either an ethanol or an alkyl substituent. Then, the cellular potency and physicochemical properties were optimized through insights from molecular modeling studies by implanting various solubilizing groups in phenyl rings A and B. Optimized lead 52 shows 8-fold selective inhibition of H1975 (EGFRL858R/T790M overexpressing) cancer cells over A431 (EGFRWT overexpressing) cancer cells; western blot analysis further confirmed EGFR mutant-selective target modulation inside the cancer cells by 52. Notably, 52 displayed in vivo antitumor effects in two different mouse xenograft models (BaF3 transfected with mutant EGFR and H1975 tumors) with TGI = 74.9 and 97.5% after oral administration (F = 27%), respectively. With an extraordinary kinome selectivity (S(10) score of 0.017), 52 undergoes detailed preclinical development.
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Antineoplásicos , Carcinoma de Pulmón de Células no Pequeñas , Receptores ErbB , Neoplasias Pulmonares , Inhibidores de Proteínas Quinasas , Pirimidinas , Animales , Humanos , Ratones , Antineoplásicos/administración & dosificación , Antineoplásicos/farmacología , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Línea Celular Tumoral , Proliferación Celular , Resistencia a Antineoplásicos , Receptores ErbB/antagonistas & inhibidores , Receptores ErbB/genética , Neoplasias Pulmonares/tratamiento farmacológico , Mutación , Inhibidores de Proteínas Quinasas/administración & dosificación , Inhibidores de Proteínas Quinasas/farmacología , Administración Oral , Pirimidinas/administración & dosificación , Pirimidinas/farmacologíaRESUMEN
Tumor necrosis factor (TNF) receptor type II (TNFR2) is expressed in various tumor cells and some immune cells, such as regulatory T cells and myeloid-derived suppressing cells. TNFR2 contributes a lot to the tumor microenvironment. For example, it directly promotes the occurrence and growth of some tumor cells, activates immunosuppressive cells, and supports immune escape. Existing studies have proved the importance of TNFR2 in cancer treatment. Here, we reviewed the activation mechanism of TNFR2 and its role in signal transduction in the tumor microenvironment. We summarized the expression and function of TNFR2 within different immune cells and the potential opportunities and challenges of targeting TNFR2 in immunotherapy. Finally, the advantages and limitations of TNFR2 to treat tumor-related diseases are discussed, and the problems that may be encountered in the clinical development and application of targeted anti-TNFR2 agonists and inhibitors are analyzed.
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Lysine benzoylation (Kbz) is a recently discovered post-translational modification associated with active transcription. However, the proteins for maintaining and interpreting Kbz and the physiological roles of Kbz remain elusive. Here, we systematically characterize writer, eraser, and reader proteins of histone Kbz in S. cerevisiae using proteomic, biochemical, and structural approaches. Our study identifies 27 Kbz sites on yeast histones that can be regulated by cellular metabolic states. The Spt-Ada-Gcn5 acetyltransferase (SAGA) complex and NAD+-dependent histone deacetylase Hst2 could function as the writer and eraser of histone Kbz, respectively. Crystal structures of Hst2 complexes reveal the molecular basis for Kbz recognition and catalysis by Hst2. In addition, we demonstrate that a subset of YEATS domains and bromodomains serve as Kbz readers, and structural analyses reveal how YEATS and bromodomains recognize Kbz marks. Moreover, the proteome-wide screening of Kbz-modified proteins identifies 207 Kbz sites on 149 non-histone proteins enriched in ribosome biogenesis, glycolysis/gluconeogenesis, and rRNA processing pathways. Our studies identify regulatory elements for the Kbz pathway and provide a framework for dissecting the biological functions of lysine benzoylation.
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Histonas , Proteínas de Saccharomyces cerevisiae , Histona Acetiltransferasas/metabolismo , Histonas/metabolismo , Lisina/metabolismo , Procesamiento Proteico-Postraduccional , Proteómica , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Sirtuina 2/metabolismoRESUMEN
BACKGROUNDS: In advanced pancreatic ductal adenocarcinoma (PDAC), immune therapy, including immune checkpoint inhibitors, has limited efficacy, encouraging the study of combination therapy. METHODS: Tumor necrosis factor receptor 2 (TNFR2) was analyzed via immunohistochemistry, immunofluorescence, western blotting, and ELISAs. The in vitro mechanism that TNFR2 regulates programmed cell death 1 ligand 1 (PD-L1) was investigated using immunofluorescence, immunohistochemistry, flow cytometry, western blotting, and chromatin immunoprecipitation (ChIP). In vivo efficacy and mechanistic studies, using C57BL/6 mice and nude mice with KPC cell-derived subcutaneous and orthotopic tumors, employed antibodies against TNFR2 and PD-L1. Survival curves were constructed for the orthotopic model and a genetically engineered PDAC model (LSL-KrasG12D/+; LSL-Trp53R172H/+; Pdx1-Cre). Mass cytometry, immunohistochemistry, and flow cytometry analyzed local and systemic alterations in the immunophenotype. RESULTS: TNFR2 showed high expression and is a prognostic factor in CD8+ T cell-enriched pancreatic cancer. TNFR2 promotes tumorigenesis and progression of pancreatic cancer via dual effect: suppressing cancer immunogenicity and partially accelerating tumor growth. TNFR2 positivity correlated with PD-L1, and in vitro and in vivo, it could regulate the expression of PDL1 at the transcription level via the p65 NF-κB pathway. Combining anti-TNFR2 and PD-L1 antibodies eradicated tumors, prolonged overall survival in pancreatic cancer, and induced strong antitumor immune memory and secondary prevention by reducing the infiltration of Tregs and tumor-associated macrophages and inducing CD8+ T cell activation in the PDAC microenvironment. Finally, the antitumor immune response derived from combination therapy is mainly dependent on CD8+ T cells, partially dependent on CD4+ T cells, and independent of natural killer cells. CONCLUSIONS: Anti-TNFR2 and anti-PD-L1 combination therapy eradicated tumors by inhibiting their growth, relieving tumor immunosuppression, and generating robust memory recall.
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Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Animales , Antígeno B7-H1 , Carcinoma Ductal Pancreático/terapia , Humanos , Inmunoterapia , Ratones , Ratones Endogámicos C57BL , Ratones Desnudos , Receptor de Muerte Celular Programada 1 , Receptores Tipo II del Factor de Necrosis Tumoral , Microambiente Tumoral , Neoplasias PancreáticasRESUMEN
G9a protein methyltransferase is a potential epigenetic drug target in different cancers and other disease conditions overexpressing the enzyme. G9a is responsible for the H3K9 dimethylation mark, which epigenetically regulates gene expression. Arg8 and Lys9 of the H3 substrate peptide are the two crucial residues for substrate-specific recognition and methylation. Several substrate competitive inhibitors are reported for the potent inhibition of G9a by incorporating lysine mimic groups in the inhibitor design. In this study, we explored the concept of arginine mimic strategy. The hydrophobic segment of the reported inhibitors BIX-01294 and UNC0638 was replaced by a guanidine moiety (side-chain moiety of arginine). The newly substituted guanidine moieties of the inhibitors were positioned similar to the Arg8 of the substrate peptide in molecular docking. Additionally, improved reactivity of the guanidine-substituted inhibitors was observed in density functional theory studies. Molecular dynamics, molecular mechanics Poisson-Boltzmann surface area binding free energy, linear interaction energy, and potential mean force calculated from steered molecular dynamics simulations of the newly designed analogues show enhanced conformational stability and improved H-bond potential and binding affinity toward the target G9a. Moreover, the presence of both lysine and arginine mimics together shows a drastic increase in the binding affinity of the inhibitor towards G9a. Hence, we propose incorporating a guanidine group to imitate the substrate arginine's side chain in the inhibitor design to improve the potency of G9a inhibitors.
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p62/SQSTM1 is frequently up-regulated in many cancers including hepatocellular carcinoma. Highly expressed p62 promotes hepato-carcinogenesis by activating many signaling pathways including Nrf2, mTORC1, and NFκB signaling. However, the underlying mechanism for p62 up-regulation in hepatocellular carcinoma remains largely unclear. Herein, we confirmed that p62 was up-regulated in hepatocellular carcinoma and its higher expression was associated with shorter overall survival in patients. The knockdown of p62 in hepatocellular carcinoma cells decreased cell growth in vitro and in vivo. Intriguingly, p62 protein stability could be reduced by its acetylation at lysine 295, which was regulated by deacetylase Sirt1 and acetyltransferase GCN5. Acetylated p62 increased its association with the E3 ligase Keap1, which facilitated its poly-ubiquitination-dependent proteasomal degradation. Moreover, Sirt1 was up-regulated to deacetylate and stabilize p62 in hepatocellular carcinoma. Additionally, Hepatocyte Sirt1 conditional knockout mice developed much fewer liver tumors after Diethynitrosamine treatment, which could be reversed by the re-introduction of exogenous p62. Taken together, Sirt1 deacetylates p62 at lysine 295 to disturb Keap1-mediated p62 poly-ubiquitination, thus up-regulating p62 expression to promote hepato-carcinogenesis. Therefore, targeting Sirt1 or p62 is a reasonable strategy for the treatment of hepatocellular carcinoma.
Asunto(s)
Carcinogénesis/metabolismo , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Sirtuina 1/metabolismo , Animales , Autofagia/fisiología , Proteína 1 Asociada A ECH Tipo Kelch/metabolismo , Ratones Endogámicos BALB C , Procesamiento Proteico-Postraduccional/fisiología , Transducción de Señal/fisiologíaRESUMEN
Chemoresistance remains a major obstacle to successful cancer therapy, especially for advanced cancers. It used to be recognised as a stable outcome resulting from genetic changes. However, recent studies showed that chemoresistance can also be unstable and reversible with the involvement of non-genetic alterations. In the present study, we found that activating transcription factor 4 (ATF4) is downregulated in chemoresistant gastric cancer cells. The over-expression of ATF4 reversed chemoresistance by activating CHOP transcription to enhance drug-induced apoptosis, and vice versa. Moreover, casein kinase 1 delta (CK1δ) was identified as the kinase responsible for ATF4-S219 phosphorylation, which triggered ßTrCP-mediated ATF4 polyubiquitination to promote its proteasomal degradation subsequently. Interestingly, drug withdrawal gradually restored chemosensitivity as well as ATF4 expression in chemoresistant cells, highlighting the dependence of dynamic drug resistance on ATF4 protein expression. In line with these findings, the inhibition of ATF4 protein degradation by CK1δ or proteasome inhibitors overcame chemoresistance both in vitro and in vivo. Taken together, these results indicate that CK1δ stimulates ßTrCP-dependent ATF4 polyubiquitination and subsequent proteasomal degradation to promote chemoresistance in gastric cancer. Stabilisation of the ATF4 protein with bortezomib (BTZ), an anticancer drug that inhibits proteasomal degradation, might be a rational strategy to improve chemotherapeutic efficacy in gastric cancer.
Asunto(s)
Factor de Transcripción Activador 4/genética , Quinasa Idelta de la Caseína/genética , Quinasa Idelta de la Caseína/metabolismo , Resistencia a Antineoplásicos/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Ubiquitinación/genética , Factor de Transcripción Activador 4/metabolismo , Animales , Línea Celular Tumoral , Modelos Animales de Enfermedad , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Complejo de la Endopetidasa ProteasomalRESUMEN
Rare oncogenic NTRK gene fusions result in uncontrolled TRK signaling leading to various adult and pediatric solid tumors. Based on the architecture of our multi-targeted clinical candidate BPR1K871 (10), we designed and synthesized a series of quinazoline compounds as selective and orally bioavailable type II TRK inhibitors. Property-driven and lead optimization strategies informed by structure-activity relationship studies led to the identification of 39, which showed higher (about 15-fold) selectivity for TRKA over AURA and AURB, as well as potent cellular activity (IC50 = 56.4 nM) against the KM12 human colorectal cancer cell line. 39 also displayed good AUC and oral bioavailability (F = 27%), excellent in vivo efficacy (TGI = 64%) in a KM12 xenograft model, and broad-spectrum anti-TRK mutant potency (IC50 = 3.74-151.4 nM), especially in the double-mutant TRKA enzymatic assays. 39 is therefore proposed for further development as a next-generation, selective, and orally-administered type II TRK inhibitor.