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1.
Redox Biol ; 38: 101766, 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-33126057

RESUMO

Idiopathic pulmonary fibrosis (IPF) is a progressive and irreversible disease characterized by an increase in differentiation of fibroblasts to myofibroblasts and excessive accumulation of extracellular matrix in lung tissue. Pharmacological activation of NRF2 has proved to be a valuable antifibrotic approach, however the detailed mechanisms of how NRF2 mediates antifibrotic function remain unclear. In this study, we found that the antifibrotic function of sulforaphane (SFN), an NRF2 activator, was largely dependent on LOC344887, a long noncoding RNA. Two functional AREs were identified in both the promoter and intron 1 of LOC344887, which defines LOC344887 as a novel anti-fibrotic NRF2 target gene. RNA-seq analysis revealed that LOC344887 controls genes and signaling pathways associated with fibrogenesis. Deletion or downregulation of LOC344887 enhanced expression of CDH2/N-cadherin, as well as a number of other fibrotic genes and blunted the antifibrotic effects of SFN. Furthermore, LOC344887-mediated downregulation of fibrotic genes may involve the PI3K-AKT signaling pathway, as pharmacologic inhibition of PI3K activity blocked the effects of LOC344887 knockdown. Our findings demonstrate that NRF2-mediated LOC344887 upregulation contributes to the antifibrotic potential of SFN by repressing the expression of CDH2 and other fibrotic genes, providing novel insight into how NRF2 controls the regulatory networks of IPF. This study provides a better understanding of the molecular mechanisms of NRF2 activators against pulmonary fibrosis and presents a novel therapeutic axis for prevention and intervention of fibrosis-related diseases.

2.
Toxicol Appl Pharmacol ; 402: 115138, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32682831

RESUMO

Chronic low dose arsenic exposure continues to be a worldwide health concern because of its prevalence and link to increased cancer risk, including non-small cell lung cancer (NSCLC). Mortality of NSCLC patients increases with the development of a metastatic lesion compared to when the tumor is localized; however, the exact mechanism for what causes NSCLC cells to metastasize in the context of environmental toxicant exposure has yet to be fully elucidated. One proposed contributor to metastasis in NSCLC is nuclear factor (erythroid-derived 2)-like 2 (NRF2), a transcription factor with known oncogenic properties that has proved to be critical for arsenic carcinogenesis. Here, we demonstrate that chronic arsenic exposure enhances the invasive and migratory capacity of immortalized lung epithelial cells via NRF2-dependent upregulation of SRY-box 9 (SOX9), another transcription factor linked with cell proliferation, epithelial-mesenchymal transition, and metastasis. We identified a functional antioxidant response element (ARE) in the promoter region of SOX9, suggesting that it is an NRF2 target gene, with mutation of the ARE preventing NRF2 binding. Pharmacological induction or inhibition of NRF2 increased or decreased SOX9 expression, respectively. Furthermore, we demonstrate that hyperactivation of NRF2 via knockout of Kelch-like ECH-associated protein 1 (KEAP1), its negative regulator, contributes to proliferation; while, inhibition of NRF2 or direct knockdown of SOX9 slowed the ability of NSCLC cells to proliferate, migrate, and invade. Overall, this study suggests that NRF2-mediated SOX9 upregulation can contribute to the metastatic potential of both environmentally and genetically driven lung tumors.

3.
Cell Chem Biol ; 27(4): 436-447, 2020 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-32275864

RESUMO

Ferroptosis is a non-apoptotic mode of regulated cell death that is iron and lipid peroxidation dependent. As new mechanistic insight into ferroptotic effectors and how they are regulated in different disease contexts is uncovered, our understanding of the physiological and pathological relevance of this mode of cell death continues to grow. Along these lines, a host of pharmacological modulators of this pathway have been identified, targeting proteins involved in iron homeostasis; the generation and reduction of lipid peroxides; or cystine import and glutathione metabolism. Also, of note, many components of the ferroptosis cascade are target genes of the transcription factor nuclear factor erythroid 2-related factor 2 (NRF2), indicating its critical role in mediating the ferroptotic response. In this review, we discuss the in vitro, in vivo, and clinical evidence of ferroptosis in disease, including a brief discussion of targeting upstream mediators of this cascade, including NRF2, to treat ferroptosis-driven diseases.

4.
PLoS Biol ; 18(2): e3000620, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32053600

RESUMO

Primary cilia are lost during cancer development, but the mechanism regulating cilia degeneration is not determined. While transcription factor nuclear factor-erythroid 2-like 2 (NRF2) protects cells from oxidative, proteotoxic, and metabolic stress in normal cells, hyperactivation of NRF2 is oncogenic, although the detailed molecular mechanisms by which uncontrolled NRF2 activation promotes cancer progression remain unclear. Here, we report that NRF2 suppresses hedgehog (Hh) signaling through Patched 1 (PTCH1) and primary ciliogenesis via p62/sequestosome 1 (SQSTM1). PTCH1, a negative regulator of Hh signaling, is an NRF2 target gene, and as such, hyperactivation of NRF2 impairs Hh signaling. NRF2 also suppresses primary cilia formation through p62-dependent inclusion body formation and blockage of Bardet-Biedl syndrome 4 (BBS4) entrance into cilia. Simultaneous ablation of PTCH1 and p62 completely abolishes NRF2-mediated inhibition of both primary ciliogenesis and Hh signaling. Our findings reveal a previously unidentified role of NRF2 in controlling a cellular organelle, the primary cilium, and its associated Hh signaling pathway and also uncover a mechanism by which NRF2 hyperactivation promotes tumor progression via primary cilia degeneration and aberrant Hh signaling. A better understanding of the crosstalk between NRF2 and primary cilia/Hh signaling could not only open new avenues for cancer therapeutic discovery but could also have significant implications regarding pathologies other than cancer, including developmental disorders, in which improper primary ciliogenesis and Hh signaling play a major role.


Assuntos
Cílios/fisiologia , Proteínas Hedgehog/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Animais , Elementos de Resposta Antioxidante , Células Cultivadas , Cílios/metabolismo , Expressão Gênica , Técnicas de Inativação de Genes , Proteínas Hedgehog/antagonistas & inibidores , Humanos , Corpos de Inclusão/metabolismo , Camundongos , Proteínas Associadas aos Microtúbulos/metabolismo , Fator 2 Relacionado a NF-E2/genética , Receptor Patched-1/genética , Receptor Patched-1/metabolismo , Proteína Sequestossoma-1/genética , Proteína Sequestossoma-1/metabolismo , Transdução de Sinais
5.
Arch Pharm Res ; 43(3): 361-369, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31372933

RESUMO

Kidney disease affects ~ 10% of the population worldwide, resulting in millions of deaths each year. Mechanistically, oxidative stress is a major driver of various kidney diseases, and promotes the progression from acute to chronic injury, as well as renal cancer development. NRF2, the master regulator of redox balance, has been shown to protect against kidney disease through its negation of reactive oxygen species (ROS). However, many kidney diseases exhibit high levels of ROS as a result of decreased NRF2 protein levels and transcriptional activity. Many studies have tested the strategy of using NRF2 inducing compounds to alleviate ROS to prevent or slow down the progression of kidney diseases. Oppositely, in specific subsets of renal cancer, NRF2 is constitutively activated and contributes to tumor burden and overall poor prognosis; therefore, there has been a recent interest in studies investigating the benefits of NRF2 inhibition. In this review, we summarize recent literature investigating the role of NRF2 and oxidative stress in various kidney diseases, and how pharmacological modification of NRF2 signaling could play a protective role.

6.
Hepatology ; 70(1): 372-388, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30873635

RESUMO

Spermidine (SPD), a naturally occurring polyamine, has been recognized as a caloric restriction mimetic that confers health benefits, presumably by inducing autophagy. Recent studies have reported that oral administration of SPD protects against liver fibrosis and hepatocarcinogenesis through activation of microtubule associated protein 1S (MAP1S)-mediated autophagy. Nuclear factor (erythroid-derived 2)-like 2 (NRF2) is a transcription factor that mediates cellular protection by maintaining the cell's redox, metabolic, and proteostatic balance. In this study, we demonstrate that SPD is a noncanonical NRF2 inducer, and that MAP1S is a component of this noncanonical pathway of NRF2 activation. Mechanistically, MAP1S induces NRF2 signaling through two parallel mechanisms, both resulting in NRF2 stabilization: (1) MAP1S competes with Kelch-like ECH-associated protein 1 (KEAP1) for NRF2 binding through an ETGE motif, and (2) MAP1S accelerates p62-dependent degradation of KEAP1 by the autophagy pathway. We further demonstrate that SPD confers liver protection by enhancing NRF2 signaling. The importance of both NRF2 and p62-dependent autophagy in SPD-mediated liver protection was confirmed using a carbon tetrachloride-induced liver fibrosis model in wild-type, Nrf2-/- , p62-/- and Nrf2-/- ;p62-/- mice, as the protective effect of SPD was significantly reduced in NRF2 or p62 single knockout mice, and completely abolished in the double knockout mice. Conclusion: Our results demonstrate the pivotal role of NRF2 in mediating the health benefit of SPD, particularly in the context of liver pathologies.


Assuntos
Cirrose Hepática/tratamento farmacológico , Fígado/efeitos dos fármacos , Proteínas Associadas aos Microtúbulos/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Espermidina/farmacologia , Animais , Autofagia , Avaliação Pré-Clínica de Medicamentos , Células HEK293 , Células Estreladas do Fígado/efeitos dos fármacos , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Camundongos , Proteínas Proto-Oncogênicas c-myc/metabolismo , Espermidina/uso terapêutico
7.
Free Radic Biol Med ; 134: 702-707, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30654017

RESUMO

NRF2, a transcription factor that has been deemed the master regulator of cellular redox homeostasis, declines with age. NRF2 transcriptionally upregulates genes that combat oxidative stress; therefore, loss of NRF2 allows oxidative stress to go unmitigated and drive the aging phenotype. Oxidative stress is a common theme among the key features associated with the aging process, collectively referred to as the "Hallmarks of Aging", as it disrupts proteostasis, alters genomic stability, and leads to cell death. In this review, we outline the role that oxidative stress and the reduction of NRF2 play in each of the Hallmarks of Aging, including how they contribute to the onset of neurodegenerative disorders, cancer, and other age-related pathologies.


Assuntos
Envelhecimento/patologia , Fator 2 Relacionado a NF-E2/metabolismo , Doenças Neurodegenerativas/patologia , Estresse Oxidativo , Envelhecimento/metabolismo , Animais , Humanos , Doenças Neurodegenerativas/metabolismo , Oxirredução , Transdução de Sinais
8.
Redox Biol ; 23: 101107, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30692038

RESUMO

The transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) is a key regulator of the cellular antioxidant response, controlling the expression of genes that counteract oxidative and electrophilic stresses. Many pathological conditions are linked to imbalances in redox homeostasis, illustrating the important role of antioxidant defense systems in preventing the pathogenic effects associated with the accumulation of reactive species. In particular, it is becoming increasingly apparent that the accumulation of lipid peroxides has an important role in driving the pathogenesis of multiple disease states. A key example of this is the recent discovery of a novel form of cell death termed ferroptosis. Ferroptosis is an iron-dependent, lipid peroxidation-driven cell death cascade that has become a key target in the development of anti-cancer therapies, as well as the prevention of neurodegenerative and cardiovascular diseases. In this review, we will provide a brief overview of lipid peroxidation, as well as key components involved in the ferroptotic cascade. We will also highlight the role of the NRF2 signaling pathway in mediating lipid peroxidation and ferroptosis, focusing on established NRF2 target genes that mitigate these pathways, as well as the relevance of the NRF2-lipid peroxidation-ferroptosis axis in disease.


Assuntos
Ferroptose , Metabolismo dos Lipídeos , Peroxidação de Lipídeos , Fator 2 Relacionado a NF-E2/metabolismo , Animais , Morte Celular , Humanos , Neoplasias/etiologia , Neoplasias/metabolismo , Neoplasias/patologia , Oxirredução , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais
9.
Annu Rev Pharmacol Toxicol ; 59: 555-575, 2019 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-30256716

RESUMO

The transcription factor nuclear factor erythroid 2 (NF-E2)-related factor 2 (NRF2) is a central regulator of redox, metabolic, and protein homeostasis that intersects with many other signaling cascades. Although the understanding of the complex nature of NRF2 signaling continues to grow, there is only one therapeutic targeting NRF2 for clinical use, dimethyl fumarate, used for the treatment of multiple sclerosis. The discovery of new therapies is confounded by the fact that NRF2 levels vary significantly depending on physiological and pathological context. Thus, properly timed and targeted manipulation of the NRF2 pathway is critical in creating effective therapeutic regimens. In this review, we summarize the regulation and downstream targets of NRF2. Furthermore, we discuss the role of NRF2 in cancer, neurodegeneration, and diabetes as well as cardiovascular, kidney, and liver disease, with a special emphasis on NRF2-based therapeutics, including those that have made it into clinical trials.


Assuntos
Fator 2 Relacionado a NF-E2/metabolismo , Transdução de Sinais/fisiologia , Animais , Humanos
10.
Proc Natl Acad Sci U S A ; 115(44): E10352-E10361, 2018 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-30309964

RESUMO

NRF2 regulates cellular redox homeostasis, metabolic balance, and proteostasis by forming a dimer with small musculoaponeurotic fibrosarcoma proteins (sMAFs) and binding to antioxidant response elements (AREs) to activate target gene transcription. In contrast, NRF2-ARE-dependent transcriptional repression is unreported. Here, we describe NRF2-mediated gene repression via a specific seven-nucleotide sequence flanking the ARE, which we term the NRF2-replication protein A1 (RPA1) element (NRE). Mechanistically, RPA1 competes with sMAF for NRF2 binding, followed by interaction of NRF2-RPA1 with the ARE-NRE and eduction of promoter activity. Genome-wide in silico and RNA-seq analyses revealed this NRF2-RPA1-ARE-NRE complex mediates negative regulation of many genes with diverse functions, indicating that this mechanism is a fundamental cellular process. Notably, repression of MYLK, which encodes the nonmuscle myosin light chain kinase, by the NRF2-RPA1-ARE-NRE complex disrupts vascular integrity in preclinical inflammatory lung injury models, illustrating the translational significance of NRF2-mediated transcriptional repression. Our findings reveal a gene-suppressive function of NRF2 and a subset of negatively regulated NRF2 target genes, underscoring the broad impact of NRF2 in physiological and pathological settings.


Assuntos
Fator 2 Relacionado a NF-E2/genética , Proteína de Replicação A/genética , Proteínas Repressoras/genética , Transcrição Genética/genética , Ativação Transcricional/genética , Células A549 , Animais , Linhagem Celular , Linhagem Celular Tumoral , Proteínas de Ligação a DNA/genética , Genoma/genética , Humanos , Camundongos , Regiões Promotoras Genéticas/genética , Elementos de Resposta/genética
12.
Mol Cell Biol ; 38(11)2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29507186

RESUMO

Environmental exposure to arsenic is linked to adverse health effects, including cancer and diabetes. Pleiotropic cellular effects are observed with arsenic exposure. Previously, we demonstrated that arsenic dysregulated the autophagy pathway at low, environmentally relevant concentrations. Here we show that arsenic blocks autophagy by preventing autophagosome-lysosome fusion. Specifically, arsenic disrupts formation of the STX17-SNAP29-VAMP8 SNARE complex, where SNAP29 mediates vesicle fusion through bridging STX17-containing autophagosomes to VAMP8-bearing lysosomes. Mechanistically, arsenic inhibits SNARE complex formation, at least in part, by enhancing O-GlcNAcylation of SNAP29. Transfection of O-GlcNAcylation-defective, but not wild-type, SNAP29 into clustered regularly interspaced short palindromic repeat (CRISPR)-mediated SNAP29 knockout cells abolishes arsenic-mediated autophagy inhibition. These findings reveal a mechanism by which low levels of arsenic perturb proteostasis through inhibition of SNARE complex formation, providing a possible therapeutic target for disease intervention in the more than 200 million people exposed to unsafe levels of arsenic.


Assuntos
Arsênico/farmacologia , Autofagia/efeitos dos fármacos , Lisossomos/metabolismo , Proteínas Qb-SNARE/metabolismo , Proteínas Qc-SNARE/metabolismo , Animais , Células HeLa , Humanos , Fusão de Membrana/fisiologia , Camundongos , Células NIH 3T3 , Fagossomos/metabolismo , Ligação Proteica , Proteínas Qb-SNARE/genética , Proteínas Qc-SNARE/genética
13.
Toxicol Appl Pharmacol ; 341: 106-113, 2018 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-29408041

RESUMO

Prolonged exposure to arsenic has been shown to increase the risk of developing a number of diseases, including cancer and type II diabetes. Arsenic is present throughout the environment in its inorganic forms, and the level of exposure varies greatly by geographical location. The current recommended maximum level of arsenic exposure by the EPA is 10µg/L, but levels>50-1000µg/L have been detected in some parts of Asia, the Middle East, and the Southwestern United States. One of the most important steps in developing treatment options for arsenic-linked pathologies is to understand the cellular pathways affected by low levels of arsenic. Here, we show that acute exposure to non-lethal, low-level arsenite, an environmentally relevant arsenical, inhibits the autophagy pathway. Furthermore, arsenite-induced autophagy inhibition initiates a transient, but moderate ER stress response. Significantly, low-level arsenite exposure does not exhibit an increase in oxidative stress. These findings indicate that compromised autophagy, and not enhanced oxidative stress occurs early during arsenite exposure, and that restoring the autophagy pathway and proper proteostasis could be a viable option for treating arsenic-linked diseases. As such, our study challenges the existing paradigm that oxidative stress is the main underlying cause of pathologies associated with environmental arsenic exposure.


Assuntos
Arsênico/toxicidade , Autofagia/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Animais , Arsênico/administração & dosagem , Autofagia/fisiologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Células HEK293 , Células HeLa , Humanos , Camundongos , Células NIH 3T3 , Estresse Oxidativo/fisiologia , Espécies Reativas de Oxigênio/metabolismo
14.
Curr Pathobiol Rep ; 5(2): 171-176, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29082113

RESUMO

PURPOSE OF REVIEW: The goal of this review is to summarize the current knowledge in the field regarding the non-canonical activation of the NRF2 pathway. Specifically, we address what role p62 plays in mediating this pathway, which pathologies have been linked to the p62-dependent activation of NRF2, as well as what therapeutic strategies could be used to treat diseases associated with the non-canonical pathway. RECENT FINDINGS: It has recently been shown that autophagic dysfunction leads to the aggregation or autophagosomal accumulation of p62, which sequesters KEAP1, resulting in prolonged activation of NRF2. The ability of p62 to outcompete NRF2 for KEAP1 binding depends on its abundance, or post-translational modifications to its key domains. Furthermore, the relevance of the p62-dependent activation of NRF2 in disease has been demonstrated in human hepatocellular carcinomas, as well as neurodegenerative diseases. SUMMARY: These findings indicate that targeting p62, or the enzymes that modify it, could prove to be an advantageous strategy for treating diseases associated with autophagy dysregulation and prolonged activation of NRF2. Other therapeutic possibilities include restoring proper autophagic function, or directly inhibiting NRF2 or its targets, to restore redox and metabolic homeostasis. Future studies will help further clarify the mechanisms, regulation, and relevance of the non-canonical pathway in driving disease pathogenesis.

15.
Trends Endocrinol Metab ; 28(11): 818-830, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28966079

RESUMO

p62, a protein capable of binding both ubiquitin and autophagy substrates, is well established as a key regulator in cancer and neurodegenerative diseases. Recently, there has been accumulating evidence that p62 is also a pivotal regulator in metabolic diseases, such as obesity, T2DM, NAFLD, metabolic bone disease, gout and thyroid disease. This review summarizes the emerging role of p62 on these diseases by considering its functional domains, phenotypes in genetically modified animals, clinically observed alterations, and its effects on downstream metabolic signaling pathways. At the same time, we highlight the need to explore the roles played by p62 in the gastrointestinal environment and immune system, and the extent to which its elevated expression may confer protection against metabolic disorders.


Assuntos
Doenças Metabólicas/genética , Doenças Metabólicas/metabolismo , Proteína Sequestossoma-1/fisiologia , Animais , Autofagia/genética , Humanos , Camundongos , Camundongos Transgênicos , Transdução de Sinais
16.
Autophagy ; 13(11): 1828-1840, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28837411

RESUMO

The production of reactive species contributes to the age-dependent accumulation of dysfunctional mitochondria and protein aggregates, all of which are associated with neurodegeneration. A putative mediator of these effects is the lipid peroxidation product 4-hydroxynonenal (4-HNE), which has been shown to inhibit mitochondrial function, and accumulate in the postmortem brains of patients with neurodegenerative diseases. This deterioration in mitochondrial quality could be due to direct effects on mitochondrial proteins, or through perturbation of the macroautophagy/autophagy pathway, which plays an essential role in removing damaged mitochondria. Here, we use a click chemistry-based approach to demonstrate that alkyne-4-HNE can adduct to specific mitochondrial and autophagy-related proteins. Furthermore, we found that at lower concentrations (5-10 µM), 4-HNE activates autophagy, whereas at higher concentrations (15 µM), autophagic flux is inhibited, correlating with the modification of key autophagy proteins at higher concentrations of alkyne-4-HNE. Increasing concentrations of 4-HNE also cause mitochondrial dysfunction by targeting complex V (the ATP synthase) in the electron transport chain, and induce significant changes in mitochondrial fission and fusion protein levels, which results in alterations to mitochondrial network length. Finally, inhibition of autophagy initiation using 3-methyladenine (3MA) also results in a significant decrease in mitochondrial function and network length. These data show that both the mitochondria and autophagy are critical targets of 4-HNE, and that the proteins targeted by 4-HNE may change based on its concentration, persistently driving cellular dysfunction.


Assuntos
Aldeídos/metabolismo , Autofagia/fisiologia , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Neurônios/fisiologia , Estresse Oxidativo , Adenina/análogos & derivados , Adenina/farmacologia , Aldeídos/análise , Aldeídos/farmacologia , Animais , Autofagia/efeitos dos fármacos , Células Cultivadas , Metabolismo Energético , Dinâmica Mitocondrial , Neurônios/citologia , Neurônios/efeitos dos fármacos , Cultura Primária de Células , Ratos
17.
Mol Carcinog ; 56(6): 1543-1553, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28112439

RESUMO

Previously, we have demonstrated that NRF2 plays a key role in mediating cisplatin resistance in ovarian cancer. To further explore the mechanism underlying NRF2-dependent cisplatin resistance, we stably overexpressed or knocked down NRF2 in parental and cisplatin-resistant human ovarian cancer cells, respectively. These two pairs of stable cell lines were then subjected to microarray analysis, where we identified 18 putative NRF2 target genes. Among these genes, ABCF2, a cytosolic member of the ABC superfamily of transporters, has previously been reported to contribute to chemoresistance in clear cell ovarian cancer. A detailed analysis on ABCF2 revealed a functional antioxidant response element (ARE) in its promoter region, establishing ABCF2 as an NRF2 target gene. Next, we investigated the contribution of ABCF2 in NRF2-mediated cisplatin resistance using our stable ovarian cancer cell lines. The NRF2-overexpressing cell line, containing high levels of ABCF2, was more resistant to cisplatin-induced apoptosis compared to its control cell line; whereas the NRF2 knockdown cell line with low levels of ABCF2, was more sensitive to cisplatin treatment than its control cell line. Furthermore, transient overexpression of ABCF2 in the parental cells decreased apoptosis and increased cell viability following cisplatin treatment. Conversely, knockdown of ABCF2 using specific siRNA notably increased apoptosis and decreased cell viability in cisplatin-resistant cells treated with cisplatin. This data indicate that the novel NRF2 target gene, ABCF2, plays a critical role in cisplatin resistance in ovarian cancer, and that targeting ABCF2 may be a new strategy to improve chemotherapeutic efficiency.


Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Antineoplásicos/farmacologia , Cisplatino/farmacologia , Resistencia a Medicamentos Antineoplásicos , Regulação Neoplásica da Expressão Gênica , Fator 2 Relacionado a NF-E2/genética , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Elementos de Resposta Antioxidante , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Feminino , Humanos , Ovário/efeitos dos fármacos , Ovário/metabolismo , Regiões Promotoras Genéticas , Regulação para Cima
18.
Prostate ; 77(1): 10-21, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27550065

RESUMO

BACKGROUND: Our goal was to investigate de novo purine biosynthetic gene PAICS expression and evaluate its role in prostate cancer progression. METHODS: Next-generation sequencing, qRTPCR and immunoblot analysis revealed an elevated expression of a de novo purine biosynthetic gene, Phosphoribosylaminoimidazole Carboxylase, Phosphoribosylaminoimidazole Succinocarboxamide Synthetase (PAICS) in a progressive manner in prostate cancer. Functional analyses were performed using prostate cancer cell lines- DU145, PC3, LnCaP, and VCaP. The oncogenic properties of PAICS were studied both by transient and stable knockdown strategies, in vivo chicken chorioallantoic membrane (CAM) and murine xenograft models. Effect of BET bromodomain inhibitor JQ1 on the expression level of PAICS was also studied. RESULTS: Molecular staging of prostate cancer is important factor in effective diagnosis, prognosis and therapy. In this study, we identified a de novo purine biosynthetic gene; PAICS is overexpressed in PCa and its expression correlated with disease aggressiveness. Through several in vitro and in vivo functional studies, we show that PAICS is necessary for proliferation and invasion in prostate cancer cells. We identified JQ1, a BET bromodomain inhibitor previously implicated in regulating MYC expression and demonstrated role in prostate cancer, abrogates PAICS expression in several prostate cancer cells. Furthermore, we observe loss of MYC occupancy on PAICS promoter in presence of JQ1. CONCLUSIONS: Here, we report that evaluation of PAICS in prostate cancer progression and its role in prostate cancer cell proliferation and invasion and suggest it as a valid therapeutic target. We suggest JQ1, a BET-domain inhibitor, as possible therapeutic option in targeting PAICS in prostate cancer. Prostate 77:10-21, 2017. © 2016 Wiley Periodicals, Inc.


Assuntos
Biomarcadores Tumorais/biossíntese , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Peptídeo Sintases/biossíntese , Neoplasias da Próstata/enzimologia , Purinas/biossíntese , Animais , Biomarcadores Tumorais/genética , Linhagem Celular Tumoral , Galinhas , Humanos , Masculino , Camundongos , Camundongos Nus , Invasividade Neoplásica/patologia , Peptídeo Sintases/genética , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Biossíntese de Proteínas/fisiologia , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
19.
Curr Pharmacol Rep ; 2(2): 91-101, 2016 04.
Artigo em Inglês | MEDLINE | ID: mdl-27313980

RESUMO

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are the clinical manifestations of severe lung damage and respiratory failure. Characterized by severe inflammation and compromised lung function, ALI/ARDS result in very high mortality of affected individuals. Currently, there are no effective treatments for ALI/ARDS, and ironically, therapies intended to aid patients (specifically mechanical ventilation, MV) may aggravate the symptoms. Key events contributing to the development of ALI/ARDS are: increased oxidative and proteotoxic stresses, unresolved inflammation, and compromised alveolar-capillary barrier function. Since the airways and lung tissues are constantly exposed to gaseous oxygen and airborne toxicants, the bronchial and alveolar epithelial cells are under higher oxidative stress than other tissues. Cellular protection against oxidative stress and xenobiotics is mainly conferred by Nrf2, a transcription factor that promotes the expression of genes that regulate oxidative stress, xenobiotic metabolism and excretion, inflammation, apoptosis, autophagy, and cellular bioenergetics. Numerous studies have demonstrated the importance of Nrf2 activation in the protection against ALI/ARDS, as pharmacological activation of Nrf2 prevents the occurrence or mitigates the severity of ALI/ARDS. Another promising new therapeutic strategy in the prevention and treatment of ALI/ARDS is the activation of autophagy, a bulk protein and organelle degradation pathway. In this review, we will discuss the strategy of concerted activation of Nrf2 and autophagy as a preventive and therapeutic intervention to ameliorate ALI/ARDS.

20.
Curr Opin Toxicol ; 1: 62-70, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-29082352

RESUMO

Pharmacological activation of the transcription factor nuclear factor-erythroid derived 2-like 2 (NRF2), the key regulator of the cellular antioxidant response, has been recognized as a feasible strategy to reduce oxidative/electrophilic stress and prevent carcinogenesis or other chronic illnesses, such as diabetes and chronic kidney disease. In contrast, due to the discovery of the "dark side" of NRF2, where prolonged activation of NRF2 causes tissue damage, cancer progression, or chemoresistance, efforts have been devoted to identify inhibitors. Currently, only one NRF2 activator has been approved for use in the clinic, while no specific NRF2 inhibitors have been discovered. Future development of NRF2-targeted therapeutics should be based on our current understanding of the regulatory mechanisms of this protein. In addition to the KEAP1-dependent mechanisms, the recent discovery of other pathways involved in the degradation of NRF2 have opened up new possibilities for the development of safe and specific therapeutics. Here, we review available and putative NRF2-targeted therapeutics and discuss their modes of action as well as their potential for disease prevention and treatment.

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