Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
1.
Hum Mol Genet ; 33(9): 818-834, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38641551

RESUMO

Telomeres are nucleoprotein structures at the end of chromosomes that maintain their integrity. Mutations in genes coding for proteins involved in telomere protection and elongation produce diseases such as dyskeratosis congenita or idiopathic pulmonary fibrosis known as telomeropathies. These diseases are characterized by premature telomere shortening, increased DNA damage and oxidative stress. Genetic diagnosis of telomeropathy patients has identified mutations in the genes TERT and TERC coding for telomerase components but the functional consequences of many of these mutations still have to be experimentally demonstrated. The activity of twelve TERT and five TERC mutants, five of them identified in Spanish patients, has been analyzed. TERT and TERC mutants were expressed in VA-13 human cells that express low telomerase levels and the activity induced was analyzed. The production of reactive oxygen species, DNA oxidation and TRF2 association at telomeres, DNA damage response and cell apoptosis were determined. Most mutations presented decreased telomerase activity, as compared to wild-type TERT and TERC. In addition, the expression of several TERT and TERC mutants induced oxidative stress, DNA oxidation, DNA damage, decreased recruitment of the shelterin component TRF2 to telomeres and increased apoptosis. These observations might indicate that the increase in DNA damage and oxidative stress observed in cells from telomeropathy patients is dependent on their TERT or TERC mutations. Therefore, analysis of the effect of TERT and TERC mutations of unknown function on DNA damage and oxidative stress could be of great utility to determine the possible pathogenicity of these variants.


Assuntos
Disceratose Congênita , Telomerase , Humanos , Apoptose/genética , DNA/metabolismo , Dano ao DNA/genética , Disceratose Congênita/genética , Disceratose Congênita/metabolismo , Disceratose Congênita/patologia , Mutação , Estresse Oxidativo/genética , RNA/genética , Telomerase/genética , Telomerase/metabolismo , Telômero/genética , Telômero/metabolismo
2.
Nucleic Acids Res ; 48(21): 12234-12251, 2020 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-33211885

RESUMO

Altered oncogene expression in cancer cells causes loss of redox homeostasis resulting in oxidative DNA damage, e.g. 8-oxoguanine (8-oxoG), repaired by base excision repair (BER). PARP1 coordinates BER and relies on the upstream 8-oxoguanine-DNA glycosylase (OGG1) to recognise and excise 8-oxoG. Here we hypothesize that OGG1 may represent an attractive target to exploit reactive oxygen species (ROS) elevation in cancer. Although OGG1 depletion is well tolerated in non-transformed cells, we report here that OGG1 depletion obstructs A3 T-cell lymphoblastic acute leukemia growth in vitro and in vivo, validating OGG1 as a potential anti-cancer target. In line with this hypothesis, we show that OGG1 inhibitors (OGG1i) target a wide range of cancer cells, with a favourable therapeutic index compared to non-transformed cells. Mechanistically, OGG1i and shRNA depletion cause S-phase DNA damage, replication stress and proliferation arrest or cell death, representing a novel mechanistic approach to target cancer. This study adds OGG1 to the list of BER factors, e.g. PARP1, as potential targets for cancer treatment.


Assuntos
Neoplasias do Colo/tratamento farmacológico , DNA Glicosilases/genética , DNA de Neoplasias/genética , Regulação Neoplásica da Expressão Gênica , Poli(ADP-Ribose) Polimerase-1/imunologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Neoplasias do Colo/mortalidade , Dano ao DNA , DNA Glicosilases/antagonistas & inibidores , DNA Glicosilases/metabolismo , Reparo do DNA/efeitos dos fármacos , Replicação do DNA/efeitos dos fármacos , DNA de Neoplasias/metabolismo , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Guanina/análogos & derivados , Guanina/metabolismo , Células HCT116 , Humanos , Camundongos , Camundongos Nus , Terapia de Alvo Molecular , Estresse Oxidativo , Poli(ADP-Ribose) Polimerase-1/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Espécies Reativas de Oxigênio/antagonistas & inibidores , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Análise de Sobrevida , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
3.
Blood ; 127(14): 1770-9, 2016 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-26903545

RESUMO

Aplastic anemia is a fatal bone marrow disorder characterized by peripheral pancytopenia and marrow hypoplasia. The disease can be hereditary or acquired and develops at any stage of life. A subgroup of the inherited form is caused by replicative impairment of hematopoietic stem and progenitor cells due to very short telomeres as a result of mutations in telomerase and other telomere components. Abnormal telomere shortening is also described in cases of acquired aplastic anemia, most likely secondary to increased turnover of bone marrow stem and progenitor cells. Here, we test the therapeutic efficacy of telomerase activation by using adeno-associated virus (AAV)9 gene therapy vectors carrying the telomerase Tert gene in 2 independent mouse models of aplastic anemia due to short telomeres (Trf1- and Tert-deficient mice). We find that a high dose of AAV9-Tert targets the bone marrow compartment, including hematopoietic stem cells. AAV9-Tert treatment after telomere attrition in bone marrow cells rescues aplastic anemia and mouse survival compared with mice treated with the empty vector. Improved survival is associated with a significant increase in telomere length in peripheral blood and bone marrow cells, as well as improved blood counts. These findings indicate that telomerase gene therapy represents a novel therapeutic strategy to treat aplastic anemia provoked or associated with short telomeres.


Assuntos
Anemia Aplástica/terapia , Dependovirus , Terapia Genética/métodos , Telomerase/biossíntese , Homeostase do Telômero , Telômero/metabolismo , Transdução Genética , Anemia Aplástica/genética , Anemia Aplástica/metabolismo , Anemia Aplástica/patologia , Animais , Modelos Animais de Doenças , Células-Tronco Hematopoéticas/metabolismo , Células-Tronco Hematopoéticas/patologia , Camundongos , Camundongos Knockout , Telomerase/genética , Telômero/genética
4.
Commun Biol ; 7(1): 353, 2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38519773

RESUMO

Cisplatin-based chemotherapy has associated clinical disadvantages, such as high toxicity and resistance. Thus, the development of new antitumor metallodrugs able to overcome different clinical barriers is a public healthcare priority. Here, we studied the mechanism of action of the isomers trans and cis-[PtI2(isopropylamine)2] (I5 and I6, respectively) against gastrointestinal cancer cells. We demonstrate that I5 and I6 modulate mitochondrial metabolism, decreasing OXPHOS activity and negatively affecting ATP-linked oxygen consumption rate. Consequently, I5 and I6 generated Reactive Oxygen Species (ROS), provoking oxidative damage and eventually the induction of senescence. Thus, herein we propose a loop with three interconnected processes modulated by these iodido agents: (i) mitochondrial dysfunction and metabolic disruptions; (ii) ROS generation and oxidative damage; and (iii) cellular senescence. Functionally, I5 reduces cancer cell clonogenicity and tumor growth in a pancreatic xenograft model without systemic toxicity, highlighting a potential anticancer complex that warrants additional pre-clinical studies.


Assuntos
Neoplasias Gastrointestinais , Platina , Humanos , Espécies Reativas de Oxigênio/metabolismo , Cisplatino/farmacologia , Mitocôndrias/metabolismo , Neoplasias Gastrointestinais/metabolismo
5.
Sci Rep ; 14(1): 15007, 2024 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-38951654

RESUMO

Salivary gland squamous cell carcinomas (SG-SCCs) constitute a rare type of head and neck cancer which is linked to poor prognosis. Due to their low frequency, the molecular mechanisms responsible for their aggressiveness are poorly understood. In this work we studied the role of the phosphatase DUSP1, a negative regulator of MAPK activity, in controlling SG-SCC progression. We generated DUSP1 KO clones in A253 human cells. These clones showed a reduced ability to grow in 2D, self-renew in ECM matrices and to form tumors in immunodeficient mice. This was caused by an overactivation of the stress and apoptosis kinase JNK1/2 in DUSP1-/+ clones. Interestingly, RNAseq analysis revealed that the expression of SOX2, a well-known self-renewal gene was decreased at the mRNA and protein levels in DUSP1-/+ cells. Unexpectedly, CRISPR-KO of SOX2 did not recapitulate DUSP1-/+ phenotype, and SOX2-null cells had an enhanced ability to self-renew and to form tumors in mice. Gene expression analysis demonstrated that SOX2-null cells have a decreased squamous differentiation profile -losing TP63 expression- and an increased migratory phenotype, with an enhanced epithelial to mesenchymal transition signature. In summary, our data indicates that DUSP1 and SOX2 have opposite functions in SG-SCC, being DUSP1 necessary for tumor growth and SOX2 dispensable showing a tumor suppressor function. Our data suggest that the combined expression of SOX2 and DUSP1 could be a useful biomarker to predict progression in patients with SG-SCCs.


Assuntos
Carcinoma de Células Escamosas , Progressão da Doença , Fosfatase 1 de Especificidade Dupla , Fatores de Transcrição SOXB1 , Neoplasias das Glândulas Salivares , Fosfatase 1 de Especificidade Dupla/metabolismo , Fosfatase 1 de Especificidade Dupla/genética , Humanos , Fatores de Transcrição SOXB1/genética , Fatores de Transcrição SOXB1/metabolismo , Animais , Camundongos , Neoplasias das Glândulas Salivares/genética , Neoplasias das Glândulas Salivares/patologia , Neoplasias das Glândulas Salivares/metabolismo , Linhagem Celular Tumoral , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/metabolismo , Regulação Neoplásica da Expressão Gênica , Proliferação de Células/genética
6.
ChemMedChem ; 18(1): e202200310, 2023 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-36128847

RESUMO

8-oxo Guanine DNA Glycosylase 1 is the initiating enzyme within base excision repair and removes oxidized guanines from damaged DNA. Since unrepaired 8-oxoG could lead to G : C→T : A transversion, base removal is of utmost importance for cells to ensure genomic integrity. For cells with elevated levels of reactive oxygen species this dependency is further increased. In the past we and others have validated OGG1 as a target for inhibitors to treat cancer and inflammation. Here, we present the optimization campaign that led to the broadly used tool compound TH5487. Based on results from a small molecule screening campaign, we performed hit to lead expansion and arrived at potent and selective substituted N-piperidinyl-benzimidazolones. Using X-ray crystallography data, we describe the surprising binding mode of the most potent member of the class, TH8535. Here, the N-Piperidinyl-linker adopts a chair instead of a boat conformation which was found for weaker analogues. We further demonstrate cellular target engagement and efficacy of TH8535 against a number of cancer cell lines.


Assuntos
DNA Glicosilases , Neoplasias , Humanos , DNA Glicosilases/química , DNA Glicosilases/genética , DNA Glicosilases/metabolismo , Guanina/química , Guanina/metabolismo , Reparo do DNA , Benzimidazóis/farmacologia , Dano ao DNA
7.
Front Oncol ; 12: 888810, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35619904

RESUMO

Background: PARP1 plays a critical role in the base excision repair (BER) pathway, and PARP1 inhibition leads to specific cell death, through a synthetic lethal interaction, in the context of BRCA1/2 deficiency. To date, up to five different PARP inhibitors (PARPi), have been approved, nevertheless, the acquisition of resistance to PARPi is common and there is increasing interest in enhancing responses and expand their use to other tumour types. Methods: We hypothesized that other BER members could be additional synthetic lethal partners with mutated BRCA genes. To test this, we decided to evaluate the glycosylase OGG1 as a potential candidate, by treating BRCA1 proficient and deficient breast cancer cells with PARPi olaparib and the OGG1 inhibitor TH5478. Results: Knocking out BRCA1 in triple-negative breast cancer cell lines causes hypersensitivity to the OGG1 inhibitor TH5487. Besides, TH5487 enhances the sensitivity to the PARP inhibitor olaparib, especially in the context of BRCA1 deficiency, reflecting an additive interaction. Discussion: These results provide the first evidence that OGG1 inhibition is a promising new synthetic lethality strategy in BRCA1-deficient cells, and could lead to a new framework for the treatment of hereditary breast and ovarian cancer.

8.
Science ; 376(6600): 1471-1476, 2022 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-35737787

RESUMO

Oxidative DNA damage is recognized by 8-oxoguanine (8-oxoG) DNA glycosylase 1 (OGG1), which excises 8-oxoG, leaving a substrate for apurinic endonuclease 1 (APE1) and initiating repair. Here, we describe a small molecule (TH10785) that interacts with the phenylalanine-319 and glycine-42 amino acids of OGG1, increases the enzyme activity 10-fold, and generates a previously undescribed ß,δ-lyase enzymatic function. TH10785 controls the catalytic activity mediated by a nitrogen base within its molecular structure. In cells, TH10785 increases OGG1 recruitment to and repair of oxidative DNA damage. This alters the repair process, which no longer requires APE1 but instead is dependent on polynucleotide kinase phosphatase (PNKP1) activity. The increased repair of oxidative DNA lesions with a small molecule may have therapeutic applications in various diseases and aging.


Assuntos
Dano ao DNA , DNA Glicosilases , Reparo do DNA , Estresse Oxidativo , Biocatálise/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , DNA Glicosilases/química , DNA Glicosilases/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Ativação Enzimática , Glicina/química , Humanos , Ligantes , Estresse Oxidativo/genética , Fenilalanina/química , Especificidade por Substrato
9.
Cancer Res ; 81(15): 4079-4093, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34045188

RESUMO

Patients with hepatocellular carcinoma (HCC) suffer from few treatment options and poor survival rates. Here we report that endonuclease VIII-like protein 3 (NEIL3) is overexpressed in HCC and correlates with poor survival. All six HCC cell lines investigated were dependent on NEIL3 catalytic activity for survival and prevention of senescence, while NEIL3 was dispensable for nontransformed cells. NEIL3-depleted HCC cell lines accumulated oxidative DNA lesions specifically at telomeres, resulting in telomere dysfunctional foci and 53BP1 foci formation. Following oxidative DNA damage during mitosis, NEIL3 relocated to telomeres and recruited apurinic endonuclease 1 (APE1), indicating activation of base excision repair. META-FISH revealed that NEIL3, but not NEIL1 or NEIL2, is required to initiate APE1 and polymerase beta (POLB)-dependent base excision repair at oxidized telomeres. Repeated exposure of NEIL3-depleted cells to oxidizing damage induced chromatin bridges and damaged telomeres. These results demonstrate a novel function for NEIL3 in repair of oxidative DNA damage at telomeres in mitosis, which is important to prevent senescence of HCC cells. Furthermore, these data suggest that NEIL3 could be a target for therapeutic intervention for HCC. SIGNIFICANCE: This study describes compartmentalization of base excision repair during mitosis that is dependent on NEIL3, APE1, and POLB to repair oxidative damage accumulating at telomeres in hepatocellular carcinoma.


Assuntos
Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/genética , Mitose/genética , N-Glicosil Hidrolases/metabolismo , Telômero/metabolismo , Humanos , Oxirredução , Transfecção
10.
Sci Rep ; 11(1): 3490, 2021 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-33568707

RESUMO

The most common oxidative DNA lesion is 8-oxoguanine which is mainly recognized and excised by the 8-oxoG DNA glycosylase 1 (OGG1), initiating the base excision repair (BER) pathway. Telomeres are particularly sensitive to oxidative stress (OS) which disrupts telomere homeostasis triggering genome instability. In the present study, we have investigated the effects of inactivating BER in OS conditions, by using a specific inhibitor of OGG1 (TH5487). We have found that in OS conditions, TH5487 blocks BER initiation at telomeres causing an accumulation of oxidized bases, that is correlated with telomere losses, micronuclei formation and mild proliferation defects. Moreover, the antimetabolite methotrexate synergizes with TH5487 through induction of intracellular reactive oxygen species (ROS) formation, which potentiates TH5487-mediated telomere and genome instability. Our findings demonstrate that OGG1 is required to protect telomeres from OS and present OGG1 inhibitors as a tool to induce oxidative DNA damage at telomeres, with the potential for developing new combination therapies for cancer treatment.


Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Benzimidazóis/farmacologia , DNA Glicosilases/antagonistas & inibidores , Reparo do DNA/efeitos dos fármacos , Metotrexato/farmacologia , Estresse Oxidativo , Piperidinas/farmacologia , Telômero/metabolismo , Ciclo Celular , Linhagem Celular Tumoral , DNA Glicosilases/metabolismo , Sinergismo Farmacológico , Inibidores Enzimáticos/farmacologia , Instabilidade Genômica , Humanos , Oxirredução , Espécies Reativas de Oxigênio/metabolismo
11.
Mol Oncol ; 13(5): 1110-1120, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30747491

RESUMO

Single nucleotide polymorphisms (SNPs) in DNA glycosylase genes involved in the base excision repair (BER) pathway can modify breast and ovarian cancer risk in BRCA1 and BRCA2 mutation carriers. We previously found that SNP rs34259 in the uracil-DNA glycosylase gene (UNG) might decrease ovarian cancer risk in BRCA2 mutation carriers. In the present study, we validated this finding in a larger series of familial breast and ovarian cancer patients to gain insights into how this UNG variant exerts its protective effect. We found that rs34259 is associated with significant UNG downregulation and with lower levels of DNA damage at telomeres. In addition, we found that this SNP is associated with significantly lower oxidative stress susceptibility and lower uracil accumulation at telomeres in BRCA2 mutation carriers. Our findings help to explain the association of this variant with a lower cancer risk in BRCA2 mutation carriers and highlight the importance of genetic changes in BER pathway genes as modifiers of cancer susceptibility for BRCA1 and BRCA2 mutation carriers.


Assuntos
Proteína BRCA2/genética , Predisposição Genética para Doença , Mutação , Neoplasias Ovarianas/genética , Polimorfismo de Nucleotídeo Único , Uracila-DNA Glicosidase/genética , Feminino , Humanos , Pessoa de Meia-Idade , Fatores de Risco
12.
Cell Death Differ ; 26(10): 1998-2014, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30670828

RESUMO

Ataxia telangiectasia (AT) is a genetic disease caused by mutations in the ATM gene but the mechanisms underlying AT are not completely understood. Key functions of the ATM protein are to sense and regulate cellular redox status and to transduce DNA double-strand break signals to downstream effectors. ATM-deficient cells show increased ROS accumulation, activation of p38 protein kinase, and increased levels of DNA damage. GSE24.2 peptide and a short derivative GSE4 peptide corresponding to an internal domain of Dyskerin have proved to induce telomerase activity, decrease oxidative stress, and protect from DNA damage in dyskeratosis congenita (DC) cells. We have found that expression of GSE24.2 and GSE4 in human AT fibroblast is able to decrease DNA damage, detected by γ-H2A.X and 53BP1 foci. However, GSE24.2/GSE4 expression does not improve double-strand break signaling and repair caused by the lack of ATM activity. In contrast, they cause a decrease in 8-oxoguanine and OGG1-derived lesions, particularly at telomeres and mitochondrial DNA, as well as in reactive oxygen species, in parallel with increased expression of SOD1. These cells also showed lower levels of IL6 and decreased p38 phosphorylation, decreased senescence and increased ability to divide for longer times. Additionally, these cells are more resistant to treatment with H202 and the radiomimetic-drug bleomycin. Finally, we found shorter telomere length (TL) in AT cells, lower levels of TERT expression, and telomerase activity that were also partially reverted by GSE4. These observations suggest that GSE4 may be considered as a new therapy for the treatment of AT that counteracts the cellular effects of high ROS levels generated in AT cells and in addition increases telomerase activity contributing to increased cell proliferation.


Assuntos
Ataxia Telangiectasia/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas Nucleares/metabolismo , Fragmentos de Peptídeos/metabolismo , Telômero/metabolismo , Ataxia Telangiectasia/genética , Ataxia Telangiectasia/patologia , Proteínas Mutadas de Ataxia Telangiectasia/genética , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Proteínas de Ciclo Celular/biossíntese , Proteínas de Ciclo Celular/química , Proteínas de Ciclo Celular/genética , Linhagem Celular , Quebras de DNA de Cadeia Dupla , Dano ao DNA , Fibroblastos/metabolismo , Fibroblastos/patologia , Humanos , Nanopartículas/química , Proteínas Nucleares/biossíntese , Proteínas Nucleares/química , Proteínas Nucleares/genética , Estresse Oxidativo/fisiologia , Fragmentos de Peptídeos/biossíntese , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/genética , Fosforilação , Espécies Reativas de Oxigênio/metabolismo , Telomerase/metabolismo , Telômero/genética , Telômero/patologia
13.
DNA Repair (Amst) ; 71: 118-126, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30228084

RESUMO

Base excision repair (BER) repairs mutagenic or genotoxic DNA base lesions, thought to be important for both the etiology and treatment of cancer. Cancer phenotypic stress induces oxidative lesions, and deamination products are responsible for one of the most prevalent mutational signatures in cancer. Chemotherapeutic agents induce genotoxic DNA base damage that are substrates for BER, while synthetic lethal approaches targeting BER-related factors are making their way into the clinic. Thus, there are three strategies by which BER is envisioned to be relevant in cancer chemotherapy: (i) to maintain cellular growth in the presence of endogenous DNA damage in stressed cancer cells, (ii) to maintain viability after exogenous DNA damage is introduced by therapeutic intervention, or (iii) to confer synthetic lethality in cancer cells that have lost one or more additional DNA repair pathways. Here, we discuss the potential treatment strategies, and briefly summarize the progress that has been made in developing inhibitors to core BER-proteins and related factors.


Assuntos
Antineoplásicos/farmacologia , Enzimas Reparadoras do DNA/antagonistas & inibidores , Reparo do DNA/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Animais , Antineoplásicos/uso terapêutico , DNA/metabolismo , Dano ao DNA , Humanos , Neoplasias/enzimologia , Neoplasias/genética , Neoplasias/metabolismo
14.
Science ; 362(6416): 834-839, 2018 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-30442810

RESUMO

The onset of inflammation is associated with reactive oxygen species and oxidative damage to macromolecules like 7,8-dihydro-8-oxoguanine (8-oxoG) in DNA. Because 8-oxoguanine DNA glycosylase 1 (OGG1) binds 8-oxoG and because Ogg1-deficient mice are resistant to acute and systemic inflammation, we hypothesized that OGG1 inhibition may represent a strategy for the prevention and treatment of inflammation. We developed TH5487, a selective active-site inhibitor of OGG1, which hampers OGG1 binding to and repair of 8-oxoG and which is well tolerated by mice. TH5487 prevents tumor necrosis factor-α-induced OGG1-DNA interactions at guanine-rich promoters of proinflammatory genes. This, in turn, decreases DNA occupancy of nuclear factor κB and proinflammatory gene expression, resulting in decreased immune cell recruitment to mouse lungs. Thus, we present a proof of concept that targeting oxidative DNA repair can alleviate inflammatory conditions in vivo.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Benzimidazóis/farmacologia , DNA Glicosilases/antagonistas & inibidores , Inibidores Enzimáticos/uso terapêutico , Expressão Gênica/efeitos dos fármacos , Inflamação/tratamento farmacológico , Piperidinas/farmacologia , Animais , Anti-Inflamatórios não Esteroides/uso terapêutico , Benzimidazóis/uso terapêutico , DNA Glicosilases/metabolismo , Reparo do DNA/efeitos dos fármacos , Reparo do DNA/genética , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Técnicas de Inativação de Genes , Guanina/análogos & derivados , Guanina/antagonistas & inibidores , Guanina/metabolismo , Células HEK293 , Humanos , Inflamação/genética , Células Jurkat , Camundongos , Camundongos Mutantes , NF-kappa B/genética , NF-kappa B/metabolismo , Piperidinas/uso terapêutico , Regiões Promotoras Genéticas , Fator de Necrose Tumoral alfa/farmacologia
16.
Oncotarget ; 8(70): 114626-114636, 2017 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-29383107

RESUMO

In this report, we have tried to gain molecular insight into a single nucleotide polymorphism (SNP) in the NEIL2 gene previously identified as "cancer risk modifier" for BRCA2 mutation carriers. To that end, we studied the role of this SNP (rs804271) on NEIL2 transcriptional regulation, oxidative DNA damage and genome instability in two independent set of samples: The first one was a series of eighty-six BRCA1 and BRCA2 mutation carriers and eighty non-carrier controls in which we evaluated the effect of the SNP on NEIL2 gene expression and oxidative DNA damage accumulation. The second was a set of twenty lymphoblastoid cell lines (LCLs), thirteen BRCA1 mutation carriers and seven non-carriers control, that were used to analyze the correlation between NEIL2 mRNA and/or protein levels, the oxidative and the double stranded break (DSB) DNA damage levels. Our results suggest that an excessive production of NEIL2 enzyme, associated with the SNP, may have a deleterious effect modifying cancer risk susceptibility in BRCA2 mutation carriers. We hypothesize that due to the SNP impact on NEIL2 transcriptional upregulation, a cascade of events may converge in the accumulation of oxidative DNA damage and its posterior conversion into DSBs for this specific group of patients.

17.
Oncotarget ; 7(18): 25815-25, 2016 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-27015555

RESUMO

We have recently shown that rs2304277 variant in the OGG1 glycosidase gene of the Base Excision Repair pathway can increase ovarian cancer risk in BRCA1 mutation carriers. In the present study, we aimed to explore the role of this genetic variant on different genome instability hallmarks to explain its association with cancer risk.We have evaluated the effect of this polymorphism on OGG1 transcriptional regulation and its contribution to telomere shortening and DNA damage accumulation. For that, we have used a series of 89 BRCA1 and BRCA2 mutation carriers, 74 BRCAX cases, 60 non-carrier controls and 23 lymphoblastoid cell lines (LCL) derived from BRCA1 mutation carriers and non-carriers.We have identified that this SNP is associated to a significant OGG1 transcriptional down regulation independently of the BRCA mutational status and that the variant may exert a synergistic effect together with BRCA1 or BRCA2 mutations on DNA damage and telomere shortening.These results suggest that this variant, could be associated to a higher cancer risk in BRCA1 mutation carriers, due to an OGG1 transcriptional down regulation and its effect on genome instability.


Assuntos
Proteína BRCA1/genética , Proteína BRCA2/genética , DNA Glicosilases/genética , Predisposição Genética para Doença/genética , Mutação , Neoplasias Ovarianas/genética , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Genótipo , Humanos , Polimorfismo de Nucleotídeo Único , Fatores de Risco
18.
Nat Commun ; 6: 8383, 2015 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-26403419

RESUMO

Cardiac angiosarcoma (CAS) is a rare malignant tumour whose genetic basis is unknown. Here we show, by whole-exome sequencing of a TP53-negative Li-Fraumeni-like (LFL) family including CAS cases, that a missense variant (p.R117C) in POT1 (protection of telomeres 1) gene is responsible for CAS. The same gene alteration is found in two other LFL families with CAS, supporting the causal effect of the identified mutation. We extend the analysis to TP53-negative LFL families with no CAS and find the same mutation in a breast AS family. The mutation is recently found once in 121,324 studied alleles in ExAC server but it is not described in any other database or found in 1,520 Spanish controls. In silico structural analysis suggests how the mutation disrupts POT1 structure. Functional and in vitro studies demonstrate that carriers of the mutation show reduced telomere-bound POT1 levels, abnormally long telomeres and increased telomere fragility.


Assuntos
Neoplasias da Mama/genética , Neoplasias Cardíacas/genética , Hemangiossarcoma/genética , Proteínas de Ligação a Telômeros/genética , Telômero/metabolismo , Adulto , Idoso , Western Blotting , Imunoprecipitação da Cromatina , Simulação por Computador , Feminino , Ensaios de Triagem em Larga Escala , Humanos , Hibridização in Situ Fluorescente , Técnicas In Vitro , Síndrome de Li-Fraumeni/genética , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Complexo Shelterina , Proteínas de Ligação a Telômeros/metabolismo , Proteína Supressora de Tumor p53/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA