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1.
Cell ; 172(1-2): 90-105.e23, 2018 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-29249359

RESUMO

R-2-hydroxyglutarate (R-2HG), produced at high levels by mutant isocitrate dehydrogenase 1/2 (IDH1/2) enzymes, was reported as an oncometabolite. We show here that R-2HG also exerts a broad anti-leukemic activity in vitro and in vivo by inhibiting leukemia cell proliferation/viability and by promoting cell-cycle arrest and apoptosis. Mechanistically, R-2HG inhibits fat mass and obesity-associated protein (FTO) activity, thereby increasing global N6-methyladenosine (m6A) RNA modification in R-2HG-sensitive leukemia cells, which in turn decreases the stability of MYC/CEBPA transcripts, leading to the suppression of relevant pathways. Ectopically expressed mutant IDH1 and S-2HG recapitulate the effects of R-2HG. High levels of FTO sensitize leukemic cells to R-2HG, whereas hyperactivation of MYC signaling confers resistance that can be reversed by the inhibition of MYC signaling. R-2HG also displays anti-tumor activity in glioma. Collectively, while R-2HG accumulated in IDH1/2 mutant cancers contributes to cancer initiation, our work demonstrates anti-tumor effects of 2HG in inhibiting proliferation/survival of FTO-high cancer cells via targeting FTO/m6A/MYC/CEBPA signaling.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Glioma/tratamento farmacológico , Glutaratos/farmacologia , Leucemia/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Adenosina/análogos & derivados , Adenosina/metabolismo , Dioxigenase FTO Dependente de alfa-Cetoglutarato/metabolismo , Animais , Antineoplásicos/uso terapêutico , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Linhagem Celular Tumoral , Glutaratos/uso terapêutico , Células HEK293 , Humanos , Células Jurkat , Camundongos , Proteínas Proto-Oncogênicas c-myc/metabolismo , Processamento Pós-Transcricional do RNA
2.
Mol Cell ; 81(5): 922-939.e9, 2021 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-33434505

RESUMO

R-2-hydroxyglutarate (R-2HG), a metabolite produced by mutant isocitrate dehydrogenases (IDHs), was recently reported to exhibit anti-tumor activity. However, its effect on cancer metabolism remains largely elusive. Here we show that R-2HG effectively attenuates aerobic glycolysis, a hallmark of cancer metabolism, in (R-2HG-sensitive) leukemia cells. Mechanistically, R-2HG abrogates fat-mass- and obesity-associated protein (FTO)/N6-methyladenosine (m6A)/YTH N6-methyladenosine RNA binding protein 2 (YTHDF2)-mediated post-transcriptional upregulation of phosphofructokinase platelet (PFKP) and lactate dehydrogenase B (LDHB) (two critical glycolytic genes) expression and thereby suppresses aerobic glycolysis. Knockdown of FTO, PFKP, or LDHB recapitulates R-2HG-induced glycolytic inhibition in (R-2HG-sensitive) leukemia cells, but not in normal CD34+ hematopoietic stem/progenitor cells, and inhibits leukemogenesis in vivo; conversely, their overexpression reverses R-2HG-induced effects. R-2HG also suppresses glycolysis and downregulates FTO/PFKP/LDHB expression in human primary IDH-wild-type acute myeloid leukemia (AML) cells, demonstrating the clinical relevance. Collectively, our study reveals previously unrecognized effects of R-2HG and RNA modification on aerobic glycolysis in leukemia, highlighting the therapeutic potential of targeting cancer epitranscriptomics and metabolism.


Assuntos
Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Antineoplásicos/farmacologia , Glutaratos/farmacologia , Glicólise/genética , Lactato Desidrogenases/genética , Leucemia Mieloide Aguda/tratamento farmacológico , Fosfofrutoquinase-1 Tipo C/genética , Dioxigenase FTO Dependente de alfa-Cetoglutarato/antagonistas & inibidores , Dioxigenase FTO Dependente de alfa-Cetoglutarato/metabolismo , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Feminino , Fluoruracila/farmacologia , Regulação Neoplásica da Expressão Gênica , Glicólise/efeitos dos fármacos , Células HEK293 , Humanos , Células K562 , Lactato Desidrogenases/antagonistas & inibidores , Lactato Desidrogenases/metabolismo , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/mortalidade , Leucemia Mieloide Aguda/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fosforilação Oxidativa/efeitos dos fármacos , Fosfofrutoquinase-1 Tipo C/antagonistas & inibidores , Fosfofrutoquinase-1 Tipo C/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Transdução de Sinais , Análise de Sobrevida , Ensaios Antitumorais Modelo de Xenoenxerto
3.
Cell ; 152(3): 599-611, 2013 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-23374352

RESUMO

Tumor cells have high-energetic and anabolic needs and are known to adapt their metabolism to be able to survive and keep proliferating under conditions of nutrient stress. We show that PKCζ deficiency promotes the plasticity necessary for cancer cells to reprogram their metabolism to utilize glutamine through the serine biosynthetic pathway in the absence of glucose. PKCζ represses the expression of two key enzymes of the pathway, PHGDH and PSAT1, and phosphorylates PHGDH at key residues to inhibit its enzymatic activity. Interestingly, the loss of PKCζ in mice results in enhanced intestinal tumorigenesis and increased levels of these two metabolic enzymes, whereas patients with low levels of PKCζ have a poor prognosis. Furthermore, PKCζ and caspase-3 activities are correlated with PHGDH levels in human intestinal tumors. Taken together, this demonstrates that PKCζ is a critical metabolic tumor suppressor in mouse and human cancer.


Assuntos
Adenocarcinoma/metabolismo , Adenoma/metabolismo , Neoplasias do Colo/metabolismo , Proteína Quinase C/metabolismo , Proteína da Polipose Adenomatosa do Colo/genética , Proteína da Polipose Adenomatosa do Colo/metabolismo , Animais , Vias Biossintéticas , Transformação Celular Neoplásica , Glucose/metabolismo , Humanos , Camundongos , Serina/biossíntese , Organismos Livres de Patógenos Específicos , Estresse Fisiológico
4.
Mol Cell ; 67(3): 512-527.e4, 2017 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-28757207

RESUMO

Aberrant signaling by the mammalian target of rapamycin (mTOR) contributes to the devastating features of cancer cells. Thus, mTOR is a critical therapeutic target and catalytic inhibitors are being investigated as anti-cancer drugs. Although mTOR inhibitors initially block cell proliferation, cell viability and migration in some cancer cells are quickly restored. Despite sustained inhibition of mTORC1/2 signaling, Akt, a kinase regulating cell survival and migration, regains phosphorylation at its regulatory sites. Mechanistically, mTORC1/2 inhibition promotes reorganization of integrin/focal adhesion kinase-mediated adhesomes, induction of IGFR/IR-dependent PI3K activation, and Akt phosphorylation via an integrin/FAK/IGFR-dependent process. This resistance mechanism contributes to xenograft tumor cell growth, which is prevented with mTOR plus IGFR inhibitors, supporting this combination as a therapeutic approach for cancers.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Neoplasias da Mama/tratamento farmacológico , Movimento Celular/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , Quinase 1 de Adesão Focal/metabolismo , Melanoma/tratamento farmacológico , Complexos Multiproteicos/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Receptores de Somatomedina/antagonistas & inibidores , Neoplasias Cutâneas/tratamento farmacológico , Serina-Treonina Quinases TOR/antagonistas & inibidores , Animais , Neoplasias da Mama/enzimologia , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Feminino , Quinase 1 de Adesão Focal/genética , Humanos , Integrina alfa2/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina , Alvo Mecanístico do Complexo 2 de Rapamicina , Melanoma/enzimologia , Melanoma/patologia , Camundongos Nus , Complexos Multiproteicos/metabolismo , Invasividade Neoplásica , Fosfatidilinositol 3-Quinase/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Interferência de RNA , Receptor IGF Tipo 1 , Receptores de Somatomedina/genética , Receptores de Somatomedina/metabolismo , Transdução de Sinais/efeitos dos fármacos , Neoplasias Cutâneas/enzimologia , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia , Serina-Treonina Quinases TOR/metabolismo , Fatores de Tempo , Transfecção , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
5.
J Biol Chem ; 299(5): 104663, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37003503

RESUMO

Microtubule-associated protein 1 light chain 3 gamma (MAP1LC3C or LC3C) is a member of the microtubule-associated family of proteins that are essential in the formation of autophagosomes and lysosomal degradation of cargo. LC3C has tumor-suppressing activity, and its expression is dependent on kidney cancer tumor suppressors, such as von Hippel-Lindau protein and folliculin. Recently, we demonstrated that LC3C autophagy is regulated by noncanonical upstream regulatory complexes and targets for degradation postdivision midbody rings associated with cancer cell stemness. Here, we show that loss of LC3C leads to peripheral positioning of the lysosomes and lysosomal exocytosis (LE). This process is independent of the autophagic activity of LC3C. Analysis of isogenic cells with low and high LE shows substantial transcriptomic reprogramming with altered expression of zinc (Zn)-related genes and activity of polycomb repressor complex 2, accompanied by a robust decrease in intracellular Zn. In addition, metabolomic analysis revealed alterations in amino acid steady-state levels. Cells with augmented LE show increased tumor initiation properties and form aggressive tumors in xenograft models. Immunocytochemistry identified high levels of lysosomal-associated membrane protein 1 on the plasma membrane of cancer cells in human clear cell renal cell carcinoma and reduced levels of Zn, suggesting that LE occurs in clear cell renal cell carcinoma, potentially contributing to the loss of Zn. These data indicate that the reprogramming of lysosomal localization and Zn metabolism with implication for epigenetic remodeling in a subpopulation of tumor-propagating cancer cells is an important aspect of tumor-suppressing activity of LC3C.


Assuntos
Carcinoma de Células Renais , Exocitose , Neoplasias Renais , Lisossomos , Proteínas Associadas aos Microtúbulos , Zinco , Animais , Humanos , Autofagia , Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/patologia , Neoplasias Renais/metabolismo , Neoplasias Renais/patologia , Lisossomos/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Zinco/metabolismo , Complexo Repressor Polycomb 2 , Epigênese Genética
6.
Int J Mol Sci ; 25(6)2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38542190

RESUMO

A glioblastoma (GBM) is one of the most aggressive, infiltrative, and treatment-resistant malignancies of the central nervous system (CNS). The current standard of care for GBMs include maximally safe tumor resection, followed by concurrent adjuvant radiation treatment and chemotherapy with the DNA alkylating agent temozolomide (TMZ), which was approved by the FDA in 2005 based on a marginal increase (~2 months) in overall survival (OS) levels. This treatment approach, while initially successful in containing and treating GBM, almost invariably fails to prevent tumor recurrence. In addition to the limited therapeutic benefit, TMZ also causes debilitating adverse events (AEs) that significantly impact the quality of life of GBM patients. Some of the most common AEs include hematologic (e.g., thrombocytopenia, neutropenia, anemia) and non-hematologic (e.g., nausea, vomiting, constipation, dizziness) toxicities. Recurrent GBMs are often resistant to TMZ and other DNA-damaging agents. Thus, there is an urgent need to devise strategies to potentiate TMZ activity, to overcome drug resistance, and to reduce dose-dependent AEs. Here, we analyze major mechanisms of the TMZ resistance-mediated intracellular signaling activation of DNA repair pathways and the overexpression of drug transporters. We review some of the approaches investigated to counteract these mechanisms of resistance to TMZ, including the use of chemosensitizers and drug delivery strategies to enhance tumoral drug exposure.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Humanos , Temozolomida/farmacologia , Temozolomida/uso terapêutico , Glioblastoma/metabolismo , Antineoplásicos Alquilantes/efeitos adversos , Qualidade de Vida , Neoplasias Encefálicas/patologia , Recidiva Local de Neoplasia/tratamento farmacológico , DNA/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Linhagem Celular Tumoral
7.
Mol Cell ; 59(3): 382-98, 2015 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-26190261

RESUMO

Insufficient nutrients disrupt physiological homeostasis, resulting in diseases and even death. Considering the physiological and pathological consequences of this metabolic stress, the adaptive responses that cells utilize under this condition are of great interest. We show that under low-glucose conditions, cells initiate adaptation followed by apoptosis responses using PERK/Akt and MEK1/ERK2 signaling, respectively. For adaptation, cells engage the ER stress-induced unfolded protein response, which results in PERK/Akt activation and cell survival. Sustained and extreme energetic stress promotes a switch to isoform-specific MEK1/ERK2 signaling, induction of GCN2/eIF2α phosphorylation, and ATF4 expression, which overrides PERK/Akt-mediated adaptation and induces apoptosis through ATF4-dependent expression of pro-apoptotic factors including Bid and Trb3. ERK2 activation during metabolic stress contributes to changes in TCA cycle and amino acid metabolism, and cell death, which is suppressed by glutamate and α-ketoglutarate supplementation. Taken together, our results reveal promising targets to protect cells or tissues from metabolic stress.


Assuntos
Glucose/farmacologia , Ácido Glutâmico/farmacologia , Ácidos Cetoglutáricos/farmacologia , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Transdução de Sinais/efeitos dos fármacos , Apoptose , Sobrevivência Celular/efeitos dos fármacos , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Células HEK293 , Humanos , Proteína Quinase 1 Ativada por Mitógeno/genética , Estresse Fisiológico/efeitos dos fármacos
8.
Br J Cancer ; 124(10): 1711-1723, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33723393

RESUMO

BACKGROUND: Activation of mTORC1 plays a significant role in cancer development and progression. However, the metabolic mechanisms to sustain mTORC1 activation of cancer cells within stressed environments are still under-appreciated. We recently revealed high autophagy activity in tumour cells with mTORC1 hyper-activation. Nevertheless, the functions and mechanisms of autophagy in regulating mTORC1 in glioma are not studied. METHODS: Using glioma patient database and human glioma cells, we assessed the mechanisms and function of selective autophagy to sustain mTORC1 hyper-activation in glioma. RESULTS: We revealed a strong association of altered mRNA levels in mTORC1 upstream and downstream genes with prognosis of glioma patients. Our results indicated that autophagy-mediated lipid catabolism was essential to sustain mTORC1 activity in glioma cells under energy stresses. We found that autophagy inhibitors or fatty acid oxidation (FAO) inhibitors in combination with 2-Deoxy-D-glucose (2DG) decreased energy production and survival of glioma cells in vitro. Consistently, inhibition of autophagy or FAO inhibitors with 2DG effectively suppressed the progression of xenografted glioma with hyper-activated mTORC1. CONCLUSIONS: This study established an autophagy/lipid degradation/FAO/ATP generation pathway, which might be used in brain cancer cells under energy stresses to maintain high mTORC1 signalling for tumour progression.


Assuntos
Autofagia/fisiologia , Neoplasias Encefálicas/metabolismo , Metabolismo Energético/fisiologia , Glioma/metabolismo , Metabolismo dos Lipídeos , Animais , Apoptose/genética , Autofagia/genética , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Progressão da Doença , Metabolismo Energético/genética , Regulação Neoplásica da Expressão Gênica , Glioma/genética , Glioma/patologia , Células HEK293 , Humanos , Metabolismo dos Lipídeos/genética , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Camundongos , Camundongos Nus , Transdução de Sinais/genética
9.
Bioinformatics ; 36(18): 4781-4788, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32653926

RESUMO

MOTIVATION: Misregulation of signaling pathway activity is etiologic for many human diseases, and modulating activity of signaling pathways is often the preferred therapeutic strategy. Understanding the mechanism of action (MOA) of bioactive chemicals in terms of targeted signaling pathways is the essential first step in evaluating their therapeutic potential. Changes in signaling pathway activity are often not reflected in changes in expression of pathway genes which makes MOA inferences from transcriptional signatures (TSeses) a difficult problem. RESULTS: We developed a new computational method for implicating pathway targets of bioactive chemicals and other cellular perturbations by integrated analysis of pathway network topology, the Library of Integrated Network-based Cellular Signature TSes of genetic perturbations of pathway genes and the TS of the perturbation. Our methodology accurately predicts signaling pathways targeted by the perturbation when current pathway analysis approaches utilizing only the TS of the perturbation fail. AVAILABILITY AND IMPLEMENTATION: Open source R package paslincs is available at https://github.com/uc-bd2k/paslincs. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Transdução de Sinais , Software , Humanos
10.
Int J Cancer ; 134(1): 9-20, 2014 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-23754313

RESUMO

Alternatively spliced tissue factor (asTF) promotes neovascularization and monocyte recruitment via integrin ligation. While asTF mRNA has been detected in some pancreatic ductal adenocarcinoma (PDAC) cell lines and increased asTF expression can promote PDAC growth in a subcutaneous model, the expression of asTF protein in bona fide PDAC lesions and/or its role in metastatic spread are yet to be ascertained. We here report that asTF protein is abundant in lesional and stromal compartments of the five studied types of carcinoma including PDAC. Analysis of 29 specimens of PDAC revealed detectable asTF in >90% of the lesions with a range of staining intensities. asTF levels in PDAC lesions positively correlated with the degree of monocyte infiltration. In an orthotopic model, asTF-overexpressing high-grade PDAC cell line Pt45P1/asTF+ produced metastases to distal lymph nodes, which stained positive for asTF. PDAC cells stimulated with and/or overexpressing asTF exhibited upregulation of genes implicated in PDAC progression and metastatic spread. Pt45P1/asTF+ cells displayed higher coagulant activity compared to Pt45P1 cells; the same effect was observed for cell-derived microparticles (MPs). Our findings demonstrate that asTF is expressed in PDAC and lymph node metastases and potentiates PDAC spread in vivo. asTF elicits global changes in gene expression likely involved in tumor progression and metastatic dissemination, and it also enhances the procoagulant potential of PDAC cells and cell-derived MPs. Thus, asTF may comprise a novel therapeutic target to treat PDAC and, possibly, its thrombotic complications.


Assuntos
Processamento Alternativo , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Tromboplastina/genética , Animais , Coagulação Sanguínea/fisiologia , Western Blotting , Citometria de Fluxo , Xenoenxertos , Humanos , Camundongos , Camundongos Nus , Invasividade Neoplásica/genética , Análise Serial de Tecidos
11.
J Immunol ; 188(1): 146-54, 2012 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-22106000

RESUMO

Previously, we reported the abrogation of quiescence and reduced survival in lymphocytes from Gimap5(sph/sph) mice, an ENU germline mutant with a missense mutation in the GTPase of immunity-associated protein 5 (Gimap5). These mice showed a progressive loss of peripheral lymphocyte populations and developed spontaneous colitis, resulting in early mortality. In this study, we identify the molecular pathways that contribute to the onset of colitis in Gimap5(sph/sph) mice. We show that CD4(+) T cells become Th1/Th17 polarized and are critically important for the development of colitis. Concomitantly, regulatory T cells become reduced in frequency in the peripheral tissues, and their immunosuppressive capacity becomes impaired. Most importantly, these progressive changes in CD4(+) T cells are associated with the loss of Forkheadbox group O (Foxo)1, Foxo3, and Foxo4 expression. Our data establish a novel link between Gimap5 and Foxo expression and provide evidence for a regulatory mechanism that controls Foxo protein expression and may help to maintain immunological tolerance.


Assuntos
Fatores de Transcrição Forkhead/imunologia , GTP Fosfo-Hidrolases/imunologia , Regulação da Expressão Gênica/imunologia , Tolerância Imunológica/fisiologia , Linfócitos T Auxiliares-Indutores/imunologia , Animais , Colite/genética , Colite/imunologia , Colite/metabolismo , Fatores de Transcrição Forkhead/biossíntese , Fatores de Transcrição Forkhead/genética , GTP Fosfo-Hidrolases/genética , GTP Fosfo-Hidrolases/metabolismo , Proteínas de Ligação ao GTP , Camundongos , Camundongos Knockout , Mutação de Sentido Incorreto , Linfócitos T Auxiliares-Indutores/metabolismo
12.
Proc Natl Acad Sci U S A ; 108(6): 2361-5, 2011 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-21262837

RESUMO

Pten inactivation promotes cell survival in leukemia cells by activating glycolytic metabolism. We found that targeting ribosomal protein S6 kinase 1 (S6K1) in Pten-deficient cells suppressed glycolysis and induced apoptosis. S6K1 knockdown decreased expression of HIF-1α, and HIF-1α was sufficient to restore glycolysis and survival of cells lacking S6K1. In the Pten(fl/fl) Mx1-Cre(+) mouse model of leukemia, S6K1 deletion delayed the development of leukemia. Thus, S6K1 is a critical mediator of glycolytic metabolism, cell survival, and leukemogenesis in Pten-deficient cells.


Assuntos
Apoptose , Glicólise , Leucemia/enzimologia , Proteínas de Neoplasias/metabolismo , PTEN Fosfo-Hidrolase/metabolismo , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismo , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Técnicas de Silenciamento de Genes , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Leucemia/genética , Camundongos , Camundongos Knockout , Proteínas de Neoplasias/genética , PTEN Fosfo-Hidrolase/genética , Proteínas Quinases S6 Ribossômicas 90-kDa/genética
13.
bioRxiv ; 2024 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-39314445

RESUMO

Metabolic dysfunction-associated steatotic liver disease (MASLD) is currently the most common liver disease, affecting up to 25% of people worldwide, featuring excessive fat accumulation in hepatocytes. Its advanced form, metabolic dysfunction-associated steatohepatitis (MASH), is a serious disease with hepatic inflammation and fibrosis, increasing the need for liver transplants. However, the pathogenic mechanism of MASLD and MASH is not fully understood. We reported that BRUCE ( BIRC6) is a liver cancer suppressor and is downregulated in MASLD/MASH patient liver specimens, though the functional role of BRUCE in MASLD/MASH remains to be elucidated. To this end, we generated liver-specific double KO (DKO) mice of BRUCE and PTEN, a major tumor suppressor and MASLD/MASH suppressor. By comparing liver histopathology among 2-3-month-old mice, there were no signs of MASLD or MASH in BRUCE liver-KO mice and only onset of steatosis in PTEN liver-KO mice. Interestingly, DKO mice had developed robust hepatic steatosis with inflammation and fibrosis. Further analysis of mitochondrial function with primary hepatocytes found moderate reduction of mitochondrial respiration, ATP production and fatty acid oxidation in BRUCE KO and the greatest reduction in DKO hepatocytes. Moreover, aberrant activation of pro-fibrotic STAT3 signaling was found in hepatic stellate cells (HSCs) in DKO mice which was prevented by administered STAT3-specific inhibitor (TTI-101). Collectively, the data demonstrates by maintaining mitochondrial metabolism BRUCE works in concert with PTEN to suppress the pro-fibrogenic STAT3 activation in HSCs and consequentially prevent MASLD/MASH. The findings highlight BRUCE being a new co-suppressor of MASLD/MASH.

14.
Cancer Res Commun ; 4(8): 2215-2227, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39087397

RESUMO

Intrinsic resistance to targeted therapeutics in PTEN-deficient glioblastoma (GBM) is mediated by redundant signaling networks that sustain critical metabolic functions. Here, we demonstrate that coordinated inhibition of the ribosomal protein S6 kinase 1 (S6K1) and the receptor tyrosine kinase AXL using LY-2584702 and BMS-777607 can overcome network redundancy to reduce GBM tumor growth. This combination of S6K1 and AXL inhibition suppressed glucose flux to pyrimidine biosynthesis. Genetic inactivation studies to map the signaling network indicated that both S6K1 and S6K2 transmit growth signals in PTEN-deficient GBM. Kinome-wide ATP binding analysis in inhibitor-treated cells revealed that LY-2584702 directly inhibited S6K1, and substrate phosphorylation studies showed that BMS-777607 inactivation of upstream AXL collaborated to reduce S6K2-mediated signal transduction. Thus, combination targeting of S6K1 and AXL provides a kinase-directed therapeutic approach that circumvents signal transduction redundancy to interrupt metabolic function and reduce growth of PTEN-deficient GBM. SIGNIFICANCE: Therapy for glioblastoma would be advanced by incorporating molecularly targeted kinase-directed agents, similar to standard of care strategies in other tumor types. Here, we identify a kinase targeting approach to inhibit the metabolism and growth of glioblastoma.


Assuntos
Receptor Tirosina Quinase Axl , Glioblastoma , PTEN Fosfo-Hidrolase , Proteínas Proto-Oncogênicas , Pirimidinas , Receptores Proteína Tirosina Quinases , Glioblastoma/tratamento farmacológico , Glioblastoma/metabolismo , Glioblastoma/patologia , Glioblastoma/genética , Humanos , Receptores Proteína Tirosina Quinases/metabolismo , Receptores Proteína Tirosina Quinases/genética , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , PTEN Fosfo-Hidrolase/metabolismo , PTEN Fosfo-Hidrolase/deficiência , PTEN Fosfo-Hidrolase/genética , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Proteínas Proto-Oncogênicas/genética , Pirimidinas/farmacologia , Linhagem Celular Tumoral , Animais , Transdução de Sinais/efeitos dos fármacos , Camundongos , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Proteínas Quinases S6 Ribossômicas 70-kDa/genética , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/genética , Ensaios Antitumorais Modelo de Xenoenxerto , Inibidores de Proteínas Quinases/farmacologia , Proliferação de Células/efeitos dos fármacos , Aminopiridinas , Piridonas
15.
bioRxiv ; 2024 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-38293110

RESUMO

Copper (Cu) is an essential trace element required for mitochondrial respiration. Late-stage clear cell renal cell carcinoma (ccRCC) accumulates Cu and allocates it to mitochondrial cytochrome c oxidase. We show that Cu drives coordinated metabolic remodeling of bioenergy, biosynthesis and redox homeostasis, promoting tumor growth and progression of ccRCC. Specifically, Cu induces TCA cycle-dependent oxidation of glucose and its utilization for glutathione biosynthesis to protect against H 2 O 2 generated during mitochondrial respiration, therefore coordinating bioenergy production with redox protection. scRNA-seq determined that ccRCC progression involves increased expression of subunits of respiratory complexes, genes in glutathione and Cu metabolism, and NRF2 targets, alongside a decrease in HIF activity, a hallmark of ccRCC. Spatial transcriptomics identified that proliferating cancer cells are embedded in clusters of cells with oxidative metabolism supporting effects of metabolic states on ccRCC progression. Our work establishes novel vulnerabilities with potential for therapeutic interventions in ccRCC. Accumulation of copper is associated with progression and relapse of ccRCC and drives tumor growth.Cu accumulation and allocation to cytochrome c oxidase (CuCOX) remodels metabolism coupling energy production and nucleotide biosynthesis with maintenance of redox homeostasis.Cu induces oxidative phosphorylation via alterations in the mitochondrial proteome and lipidome necessary for the formation of the respiratory supercomplexes. Cu stimulates glutathione biosynthesis and glutathione derived specifically from glucose is necessary for survival of Cu Hi cells. Biosynthesis of glucose-derived glutathione requires activity of glutamyl pyruvate transaminase 2, entry of glucose-derived pyruvate to mitochondria via alanine, and the glutamate exporter, SLC25A22. Glutathione derived from glucose maintains redox homeostasis in Cu-treated cells, reducing Cu-H 2 O 2 Fenton-like reaction mediated cell death. Progression of human ccRCC is associated with gene expression signature characterized by induction of ETC/OxPhos/GSH/Cu-related genes and decrease in HIF/glycolytic genes in subpopulations of cancer cells. Enhanced, concordant expression of genes related to ETC/OxPhos, GSH, and Cu characterizes metabolically active subpopulations of ccRCC cells in regions adjacent to proliferative subpopulations of ccRCC cells, implicating oxidative metabolism in supporting tumor growth.

16.
J Immunol ; 186(1): 156-63, 2011 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-21098226

RESUMO

We have previously shown that regulatory T cells (Treg) accumulate dramatically in aged animals and negatively impact the ability to control persistent infection. However, the mechanisms underlying the age-dependent accrual of Treg remain unclear. In this study, we show that Treg accumulation with age is progressive and likely not the result of increased thymic output, increased peripheral proliferation, or from enhanced peripheral conversion. Instead, we found that Treg from aged mice are more resistant to apoptosis than Treg from young mice. Although Treg from aged mice had increased expression of functional IL-7Rα, we found that IL-7R signaling was not required for maintenance of Treg in vivo. Notably, aged Treg exhibit decreased expression of the proapoptotic molecule Bim compared with Treg from young mice. Furthermore, in the absence of Bim, Treg accumulate rapidly, accounting for >25% of the CD4(+) T cell compartment by 6 mo of age. Additionally, accumulation of Treg in Bim-deficient mice occurred after the cells left the transitional recent thymic emigrant compartment. Mechanistically, we show that IL-2 drives preferential proliferation and accumulation of Bim(lo) Treg. Collectively, our data suggest that chronic stimulation by IL-2 leads to preferential expansion of Treg having low expression of Bim, which favors their survival and accumulation in aged hosts.


Assuntos
Proteínas Reguladoras de Apoptose/fisiologia , Homeostase/imunologia , Proteínas de Membrana/fisiologia , Proteínas Proto-Oncogênicas/fisiologia , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Envelhecimento/genética , Envelhecimento/imunologia , Animais , Proteínas Reguladoras de Apoptose/deficiência , Proteínas Reguladoras de Apoptose/genética , Proteína 11 Semelhante a Bcl-2 , Sobrevivência Celular/genética , Sobrevivência Celular/imunologia , Células Cultivadas , Técnicas de Introdução de Genes , Homeostase/genética , Humanos , Contagem de Linfócitos , Proteínas de Membrana/deficiência , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Proto-Oncogênicas/deficiência , Proteínas Proto-Oncogênicas/genética , Timo/citologia , Timo/imunologia
17.
Cell Rep ; 42(8): 112868, 2023 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-37494188

RESUMO

Cells maintain and dynamically change their proteomes according to the environment and their needs. Mechanistic target of rapamycin (mTOR) is a key regulator of proteostasis, homeostasis of the proteome. Thus, dysregulation of mTOR leads to changes in proteostasis and the consequent progression of diseases, including cancer. Based on the physiological and clinical importance of mTOR signaling, we investigated mTOR feedback signaling, proteostasis, and cell fate. Here, we reveal that mTOR targeting inhibits eIF4E-mediated cap-dependent translation, but feedback signaling activates a translation initiation factor, eukaryotic translation initiation factor 3D (eIF3D), to sustain alternative non-canonical translation mechanisms. Importantly, eIF3D-mediated protein synthesis enables cell phenotype switching from proliferative to more migratory. eIF3D cooperates with mRNA-binding proteins such as heterogeneous nuclear ribonucleoprotein F (hnRNPF), heterogeneous nuclear ribonucleoprotein K (hnRNPK), and Sjogren syndrome antigen B (SSB) to support selective mRNA translation following mTOR inhibition, which upregulates and activates proteins involved in insulin receptor (INSR)/insulin-like growth factor 1 receptor (IGF1R)/insulin receptor substrate (IRS) and interleukin 6 signal transducer (IL-6ST)/Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling. Our study highlights the mechanisms by which cells establish the dynamic change of proteostasis and the resulting phenotype switch.


Assuntos
Proteostase , Receptor de Insulina , RNA Mensageiro/metabolismo , Receptor de Insulina/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Sirolimo , Biossíntese de Proteínas
18.
Sci Rep ; 13(1): 12433, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37528157

RESUMO

Low-grade and secondary high-grade gliomas frequently contain mutations in the IDH1 or IDH2 metabolic enzymes that are hypothesized to drive tumorigenesis by inhibiting many of the chromatin-regulating enzymes that regulate DNA structure. Histone deacetylase inhibitors are promising anti-cancer agents and have already been used in clinical trials. However, a clear understanding of their mechanism or gene targets is lacking. In this study, the authors genetically dissect patient-derived IDH1 mutant cultures to determine which HDAC enzymes drive growth in IDH1 mutant gliomas. A panel of patient-derived gliomasphere cell lines (2 IDH1 mutant lines, 3 IDH1 wildtype lines) were subjected to a drug-screen of epigenetic modifying drugs from different epigenetic classes. The effect of LBH (panobinostat) on gene expression and chromatin structure was tested on patient-derived IDH1 mutant lines. The role of each of the highly expressed HDAC enzymes was molecularly dissected using lentiviral RNA interference knock-down vectors and a patient-derived IDH1 mutant in vitro model of glioblastoma (HK252). These results were then confirmed in an in vivo xenotransplant model (BT-142). The IDH1 mutation leads to gene down-regulation, DNA hypermethylation, increased DNA accessibility and H3K27 hypo-acetylation in two distinct IDH1 mutant over-expression models. The drug screen identified histone deacetylase inhibitors (HDACi) and panobinostat (LBH) more specifically as the most selective compounds to inhibit growth in IDH1 mutant glioma lines. Of the eleven annotated HDAC enzymes (HDAC1-11) only six are expressed in IDH1 mutant glioma tissue samples and patient-derived gliomasphere lines (HDAC1-4, HDAC6, and HDAC9). Lentiviral knock-down experiments revealed that HDAC1 and HDAC6 are the most consistently essential for growth both in vitro and in vivo and target very different gene modules. Knock-down of HDAC1 or HDAC6 in vivo led to a more circumscribed less invasive tumor. The gene dysregulation induced by the IDH1 mutation is wide-spread and only partially reversible by direct IDH1 inhibition. This study identifies HDAC1 and HDAC6 as important and drug-targetable enzymes that are necessary for growth and invasiveness in IDH1 mutant gliomas.


Assuntos
Antineoplásicos , Neoplasias Encefálicas , Glioma , Humanos , Panobinostat/farmacologia , Panobinostat/uso terapêutico , Inibidores de Histona Desacetilases/farmacologia , Inibidores de Histona Desacetilases/uso terapêutico , Glioma/metabolismo , Antineoplásicos/uso terapêutico , Cromatina , Isocitrato Desidrogenase/genética , Isocitrato Desidrogenase/metabolismo , Mutação , Neoplasias Encefálicas/patologia , Histona Desacetilase 1/genética , Desacetilase 6 de Histona/genética
19.
Cancer Chemother Pharmacol ; 90(4): 345-356, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36050497

RESUMO

PURPOSE: The DNA alkylating agent temozolomide (TMZ), is the first-line therapeutic for the treatment of glioblastoma (GBM). However, its use is confounded by the occurrence of drug resistance and debilitating adverse effects. Previously, we observed that letrozole (LTZ), an aromatase inhibitor, has potent activity against GBM in pre-clinical models. Here, we evaluated the effect of LTZ on TMZ activity against patient-derived GBM cells. METHODS: Employing patient-derived G76 (TMZ-sensitive), BT142 (TMZ-intermediately sensitive) and G43 and G75 (TMZ-resistant) GBM lines we assessed the influence of LTZ and TMZ on cell viability and neurosphere growth. Combination Index (CI) analysis was performed to gain quantitative insights of this interaction. We then assessed DNA damaging effects by conducting flow-cytometric analysis of Ë H2A.X formation and induction of apoptotic signaling pathways (caspase3/7 activity). The effects of adding estradiol on LTZ-induced cytotoxicity and DNA damage were also evaluated. RESULTS: Co-treatment with LTZ at a non-cytotoxic concentration (40 nM) reduced TMZ IC50 by 8, 37, 240 and 640 folds in G76, BT-142, G43 and G75 cells, respectively. The interaction was deemed to be synergistic based on CI analysis. LTZ co-treatment also significantly increased DNA damaging effects of TMZ. Addition of estradiol abrogated these LTZ effects. CONCLUSIONS: LTZ increases DNA damage and synergistically enhances TMZ activity in TMZ sensitive and TMZ-resistant GBM lines. These effects are abrogated by the addition of exogenous estradiol underscoring that the observed effects of LTZ may be mediated by estrogen deprivation. Our study provides a strong rationale for investigating the clinical potential of combining LTZ and TMZ for GBM therapy.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Antineoplásicos Alquilantes/farmacologia , Antineoplásicos Alquilantes/uso terapêutico , Inibidores da Aromatase/farmacologia , Neoplasias Encefálicas/genética , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Estradiol/farmacologia , Glioblastoma/metabolismo , Humanos , Letrozol/farmacologia , Letrozol/uso terapêutico , Temozolomida/farmacologia , Temozolomida/uso terapêutico
20.
Sci Rep ; 12(1): 8221, 2022 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-35581287

RESUMO

The pathological changes in epigenetics and gene regulation that accompany the progression of low-grade to high-grade gliomas are under-studied. The authors use a large set of paired atac-seq and RNA-seq data from surgically resected glioma specimens to infer gene regulatory relationships in glioma. Thirty-eight glioma patient samples underwent atac-seq sequencing and 16 samples underwent additional RNA-seq analysis. Using an atac-seq/RNA-seq correlation matrix, atac-seq peaks were paired with genes based on high correlation values (|r2| > 0.6). Samples clustered by IDH1 status but not by grade. Surprisingly there was a trend for IDH1 mutant samples to have more peaks. The majority of peaks are positively correlated with survival and positively correlated with gene expression. Constructing a model of the top six atac-seq peaks created a highly accurate survival prediction model (r2 = 0.68). Four of these peaks were still significant after controlling for age, grade, pathology, IDH1 status and gender. Grade II, III, and IV (primary) samples have similar transcription factors and gene modules. However, grade IV (recurrent) samples have strikingly few peaks. Patient-derived glioma cultures showed decreased peak counts following radiation indicating that this may be radiation-induced. This study supports the notion that IDH1 mutant and IDH1 wildtype gliomas have different epigenetic landscapes and that accessible chromatin sites mapped by atac-seq peaks tend to be positively correlated with expression. The data in this study leads to a new model of treatment response wherein glioma cells respond to radiation therapy by closing open regions of DNA.


Assuntos
Glioma , Cromatina/genética , Sequenciamento de Cromatina por Imunoprecipitação , DNA/genética , Glioma/genética , Glioma/patologia , Humanos , Fatores de Transcrição/genética
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