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1.
Bratisl Lek Listy ; 120(9): 646-649, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31475547

RESUMO

BACKGROUND: It has been demonstrated that proteasome inhibitors might be potential anticancer drugs. The copper complexes can be used as specific proteasome inhibitors in tumor cells able to induce apoptosis by the ubiquitin-proteasome pathway. The goal of our study was to test the cytotoxic and proteasome inhibitory effects of five Schiff base Cu(II) complexes - [Cu2(sal-D,L-glu)2(isoquinoline)2] . 2C2H5OH (1), [Cu(sal-5-met-L-glu)(H2O)].H2O (2), [Cu(ethanol)2(imidazole)4][Cu2(sal-D,L-glu)2(imidazole)2] (3), [Cu(sal-D,L-glu)(2-methylimidazole)] (4) on human lung carcinoma cells A549, cervix carcinoma cells HeLa and glioblastoma cells U-118MG. MATERIAL AND METHODS: For the cytotoxic analysis we used MTT test and for monitoring the proteasome inhibition western blot analysis. RESULTS: We have observed different cytotoxic effects of tested complexes on human cancer cells depending on the ligand present in their structure. Cu(II) complexes 4 and 5 were the most effective against A549 cells; all complexes were cytotoxic against HeLa cells and the complex 4 was the most effective against U-118MG. Moreover, we have detected the inhibition of the proteasome activity in human cancer cells A549 by Cu(II) complexes 1, 2 and 4 at IC50 concentration. CONCLUSION: Results of our study suggest that isoquinoline- and imidazole-based copper complexes could be used as inhibitors of the proteasome system in cancer cells A549 (Tab. 1, Fig. 1, Ref. 26).


Assuntos
Cobre/farmacologia , Inibidores de Proteassoma/farmacologia , Bases de Schiff/farmacologia , Células A549 , Antineoplásicos/farmacologia , Apoptose , Complexos de Coordenação/farmacologia , Células HeLa , Humanos , Complexo de Endopeptidases do Proteassoma
2.
Chem Commun (Camb) ; 55(66): 9869-9872, 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31364617

RESUMO

In this work, we designed and synthesized an aggregation-induced emission (AIE)-active tetraphenylethene-decorated pseudo-trisialic acid (TPE3S) and validated its high affinity for Siglecs using microscale thermophoresis techniques. TPE3S was a unique binding-on fluorescent trivalent sialocluster which was successfully utilized for the visualization of Siglecs expressed on the surface of mammalian cells.


Assuntos
Metabolismo dos Carboidratos , Lectinas/metabolismo , Lectinas Semelhantes a Imunoglobulina de Ligação ao Ácido Siálico/metabolismo , Animais , Membrana Celular/metabolismo , Corantes Fluorescentes/química , Células HeLa , Humanos , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Células PC12 , Ligação Proteica , Ratos
4.
Life Sci ; 234: 116789, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31454494

RESUMO

OBJECTIVES: The aim of this study was to uncover the underlying mechanisms of cervical cancer progression and provide potential therapeutic targets for its treatment in clinic. MATERIALS AND METHODS: Real-Time qPCR was used to determine the expression levels of Linc00483, miR-508-3p and RGS17 mRNA in cervical cancer tissues and cell lines. Terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL) assay was conducted to determine cell apoptosis. Western Blot was performed to detect protein expression levels. Wound healing and Transwell assay were employed to determine cell migration and invasion respectively. Online software (TargetScan, miRDB and miR TarBase) were used to predict the regulating mechanisms of Linc00483, miR-508-3p and RGS17, which were validated by dual-luciferase reporter gene system. In vivo tumor-bearing mice models were established to validate the cellular results. RESULTS: Linc00483 aberrantly overexpressed in both cervical cancer tissues and cell lines comparing to the Control groups. Knock-down of Linc00483 inhibited cervical cancer cell proliferation, invasion as well as migration, and promoted cell apoptosis. In addition, miR-508-3p was identified as the downstream target of Linc00483, and miR-508-3p inhibitor abrogated the inhibiting effects of downregulated Linc00483 on cervical cancer cell viability. Furthermore, the expression levels of Linc00483 was positively correlated with RGS17 in the clinical samples and overexpressed Linc00483 increased RGS17 expression levels in cervical cancer cells by sponging miR-508-3p. The in vivo experiments showed that knock-down of Linc00483 inhibited cervical cancer cell tumorigenesis and lung metastasis in mice models. CONCLUSIONS: Knock-down of Linc00483 inhibited the development of cervical cancer by regulating miR-508-3p/RGS17 axis.


Assuntos
Carcinogênese/genética , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Proteínas RGS/genética , RNA Longo não Codificante/genética , Neoplasias do Colo do Útero/genética , Adulto , Animais , Carcinogênese/patologia , Feminino , Células HeLa , Humanos , Camundongos Nus , Pessoa de Meia-Idade , Neoplasias do Colo do Útero/patologia
5.
J Enzyme Inhib Med Chem ; 34(1): 1481-1488, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31423846

RESUMO

Indoleamine 2,3-dioxygenase 1 (IDO1), a tryptophan catabolising enzyme, is known as a tumour cell survival factor that causes immune escape in several types of cancer. Flavonoids of Sophora flavescens have a variety of biological benefits for humans; however, cancer immunotherapy effect has not been fully investigated. The flavonoids (1-6) isolated from S. flavescens showed IDO1 inhibitory activities (IC50 4.3-31.4 µM). The representative flavonoids (4-6) of S. flavescens were determined to be non-competitive inhibitors of IDO1 by kinetic analyses. Their binding affinity to IDO1 was confirmed using thermal stability and surface plasmon resonance (SPR) assays. The molecular docking analysis and mutagenesis assay revealed the structural details of the interactions between the flavonoids (1-6) and IDO1. These results suggest that the flavonoids (1-6) of S. flavescens, especially kushenol E (6), as IDO1 inhibitors might be useful in the development of immunotherapeutic agents against cancers.


Assuntos
Antineoplásicos/farmacologia , Inibidores Enzimáticos/farmacologia , Flavonoides/farmacologia , Indolamina-Pirrol 2,3,-Dioxigenase/antagonistas & inibidores , Sophora/química , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos/química , Inibidores Enzimáticos/isolamento & purificação , Flavonoides/química , Flavonoides/isolamento & purificação , Células HeLa , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/genética , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Modelos Moleculares , Estrutura Molecular , Mutagênese Sítio-Dirigida , Relação Estrutura-Atividade , Células Tumorais Cultivadas
6.
Chem Commun (Camb) ; 55(72): 10654-10664, 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31418758

RESUMO

Some host-guest complexes of cucurbit[n]uril (CB[n]) host molecules act as supramolecular amphiphiles (SAs), which hierarchically self-assemble into various nanomaterials such as vesicles, micelles, nanorods, and nanosheets in water. The structures and functions of the nanomaterials can be controlled by supramolecular engineering of the host-guest complexes. In addition, functionalization at the periphery of CB[6] and CB[7] generates CB[n]-based molecular amphiphiles (MAs) that can also self-assemble into vesicles or micelle-like nanoparticles in water. Taking advantage of the molecular cavities of CBs and their strong guest recognition properties, the surface of the self-assembled nanomaterials can be easily decorated with various functional tags in a non-covalent manner. In this feature article, the two types (SAs and MAs) of CB-based amphiphiles, their self-assemblies and their applications for nanotherapeutics and theranostics are presented with future perspectives.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Hidrocarbonetos Aromáticos com Pontes/farmacologia , Doxorrubicina/farmacologia , Nanoestruturas/química , Tensoativos/farmacologia , Antibióticos Antineoplásicos/química , Hidrocarbonetos Aromáticos com Pontes/química , Proliferação de Células/efeitos dos fármacos , Doxorrubicina/química , Células HeLa , Humanos , Células KB , Tensoativos/química
7.
Chem Commun (Camb) ; 55(70): 10456-10459, 2019 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-31411211

RESUMO

A bio-orthogonal chemistry-based approach for fluorescent labelling of ribosomal RNA is described. It involves an adenosine analogue modified with trans-cyclooctene and masked 5'-phosphate group using aryl phosphoramidate. The incorporation into rRNA has been confirmed using agarose gel electrophoresis, as well as a highly sensitive UHPLC-MS/MS method. Fluorescent labelling of rRNA has been achieved in live HeLa cells via an inverse electron demand Diels-Alder reaction with a tetrazine conjugated to an Oregon Green fluorophore. This communication describes the stepwise approach that led to the development and characterization of the probe. The results demonstrate a new strategy towards development of future fluorescent probes to investigate the biochemistry of nucleic acids.


Assuntos
Corantes Fluorescentes/química , RNA Ribossômico/química , Cromatografia Líquida de Alta Pressão/métodos , Reação de Cicloadição , Células HeLa , Humanos , Espectrometria de Massas em Tandem/métodos
8.
Cell Mol Biol Lett ; 24: 49, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31333726

RESUMO

Background: Synuclein-γ has been demonstrated to be highly expressed in various human cancers including cervical cancer, and has been shown to play a critical role in tumor aggressiveness. We aimed to investigate the role of Synuclein-γ in human cervical cancer in vitro and in vivo. Method: Reverse transcription-quantitative polymerase chain reaction assay and Western blot assay were used to detect the mRNA and protein expression, respectively. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and colony formation assay were performed to measure the viabilities of cancer cells. Flow cytometry assay was used to detect the cell cycle and apoptosis. Moreover, an animal experiment was performed to evaluate the biological behavior of Synuclein-γ in vivo. Results: In the current study, we found that Synuclein-γ was obviously over-expressed in cervical cancer tissues compared to the adjacent non-cancer tissues. Cervical cancer cells transfected with Synuclein-γ siRNA demonstrated significant inhibition of cancer proliferation (P < 0.01), cell cycle arrest at G0/G1 phase, and cell apoptosis (P < 0.05). Moreover, down-regulation of Synuclein-γ significantly inhibited cervical cancer growth in vivo. In addition, protein levels of AKT, c-Myc and Cyclin D1 were much lower in the Synuclein-γ siRNA-treated groups than that in the control group. Conclusions: Synuclein-γ inhibition reduced cervical cancer tumor growth through the AKT pathway. This effect represented a therapeutic opportunity and provided a novel target for cervical cancer treatment.


Assuntos
Proteínas de Neoplasias/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Neoplasias do Colo do Útero/metabolismo , gama-Sinucleína/metabolismo , Apoptose , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Regulação Neoplásica da Expressão Gênica , Células HeLa , Humanos , Pessoa de Meia-Idade , Neoplasias do Colo do Útero/fisiopatologia
9.
Chem Commun (Camb) ; 55(57): 8329-8332, 2019 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-31257378

RESUMO

Cell imaging heavily depends on fluorescent labels typically incompatible with Raman microscopy. The europium(iii) complex based on dipicolinic acid (DPA) presented here is an exception from this rule. Although its luminescence bands are very narrow, their intensity is comparable to the background Raman bands. This makes it complementary to less luminous compounds referred to as Raman tags. Through several examples we show that the complex provides a morphological context in otherwise unstained cells, thus acting as a spectral-counterstaining agent.


Assuntos
Complexos de Coordenação/química , Análise Espectral Raman , Candida albicans/metabolismo , Parede Celular/química , Células Epiteliais/química , Células Epiteliais/citologia , Európio/química , Células HeLa , Humanos , Microscopia de Fluorescência , Ácidos Picolínicos/química
10.
Chem Commun (Camb) ; 55(61): 9015-9018, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31290867
11.
Chem Commun (Camb) ; 55(61): 9039-9042, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31292589
12.
Nat Commun ; 10(1): 2905, 2019 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-31266953

RESUMO

Delivery into mammalian cells remains a significant challenge for many applications of proteins as research tools and therapeutics. We recently reported that the fusion of cargo proteins to a supernegatively charged (-30)GFP enhances encapsulation by cationic lipids and delivery into mammalian cells. To discover polyanionic proteins with optimal delivery properties, we evaluate negatively charged natural human proteins for their ability to deliver proteins into cultured mammalian cells and human primary fibroblasts. Here we discover that ProTα, a small, widely expressed, intrinsically disordered human protein, enables up to ~10-fold more efficient cationic lipid-mediated protein delivery compared to (-30)GFP. ProTα enables efficient delivery at low- to mid-nM concentrations of two unrelated genome editing proteins, Cre recombinase and zinc-finger nucleases, under conditions in which (-30)GFP fusion or cationic lipid alone does not result in substantial activity. ProTα may enable mammalian cell protein delivery applications when delivery potency is limiting.


Assuntos
Edição de Genes/métodos , Lipossomos/química , Proteínas/química , Edição de Genes/instrumentação , Proteínas de Fluorescência Verde/química , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Células HeLa , Humanos , Integrases/química , Integrases/genética , Integrases/metabolismo , Lipossomos/metabolismo , Transporte Proteico , Proteínas/genética , Proteínas/metabolismo , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Nucleases de Dedos de Zinco/química , Nucleases de Dedos de Zinco/genética , Nucleases de Dedos de Zinco/metabolismo
13.
Chem Commun (Camb) ; 55(65): 9629-9632, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31353368

RESUMO

Excessive accumulation of reducing agents in the ER leads to a constitutively high UPR. And the co-function of GSH, Cys and HOCl in biological processes is not well understood. To address this, a TP probe, NPCC, was developed for monitoring reductive stress in the ER. It can also distinguish cancer cells from normal cells.


Assuntos
Cumarínicos/química , Estresse do Retículo Endoplasmático/fisiologia , Retículo Endoplasmático/metabolismo , Corantes Fluorescentes/química , Pirazóis/química , Animais , Cumarínicos/síntese química , Cisteína/química , Cisteína/metabolismo , Corantes Fluorescentes/síntese química , Glutationa/química , Glutationa/metabolismo , Cabras , Células HeLa , Humanos , Ácido Hipocloroso/química , Ácido Hipocloroso/metabolismo , Camundongos , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Oxirredução , Pirazóis/síntese química , Peixe-Zebra
14.
J Phys Chem Lett ; 10(14): 4123-4128, 2019 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-31287699

RESUMO

Delivering potential theranostic metal complexes into preferential cellular targets is becoming of increasing interest. Here we report that nuclear uptake of a cell-impermeable DNA "light-switching" Ru(II)-polypyridyl complex can be significantly facilitated by chlorophenolate counter-anions, which was found, unexpectedly, to be correlated positively with the binding stability but inversely with the lipophilicity of the formed ion pairs.


Assuntos
Clorofenóis/química , Complexos de Coordenação/química , DNA/química , Piridinas/química , Rutênio/química , Química Física , Células HeLa , Humanos , Íons/química , Estrutura Molecular , Polímeros/química
15.
Chem Commun (Camb) ; 55(58): 8494-8497, 2019 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-31268095

RESUMO

A rational strategy was reported to construct boranil complexes (DPFB derivatives) with unique aggregation-induced emission effects by installing phenyl rings in the anil ligand as the intramolecular rotors. In view of the good biocompatibility and suitable lipophilicity, DPFB derivatives can serve as excellent fluorescent probes for specific imaging of lipid droplets in living cells and yolk lipids in zebrafish.


Assuntos
Compostos de Anilina/química , Compostos de Boro/química , Complexos de Coordenação/química , Corantes Fluorescentes/química , Gotículas Lipídicas/metabolismo , Compostos de Anilina/síntese química , Animais , Compostos de Boro/síntese química , Complexos de Coordenação/síntese química , Fluorescência , Corantes Fluorescentes/síntese química , Células HeLa , Humanos , Ligantes , Microscopia Confocal/métodos , Estrutura Molecular , Peixe-Zebra
16.
Anticancer Res ; 39(7): 3697-3709, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31262896

RESUMO

BACKGROUND/AIM: Cervical cancer is considered poorly chemo-sensitive in women and its treatment remains unsatisfactory. Cyperus rotundus is used in Chinese medicine as a therapeutic agent for women's disease. The effects and molecular mechanisms of the ethanol extraction of C. rotundus (CRE) on cervical cancer remain unclear. We aimed to explore the mechanisms and genetic influence of CRE on cervical cancer. MATERIALS AND METHODS: HeLa, human cervical cancer cells were treated with various doses of CRE and changes in cell morphology and cell viability were assessed using microscopy and flow cytometry. Finally, we performed a microarray analysis to scan related genes. RESULTS: The treatment of CRE on HeLa cells caused morphological changes and induced chromatin condensation. DNA microarray analysis showed that CRE led to up-regulation of 449 genes and down-regulation of 484 genes, which were classified in several interaction pathways. CONCLUSION: CRE changed HeLa cell morphology and induced gene expression which associated with apoptosis and cell-cycle arrest. These results provide important information at the transcription level for targeting treatments of human cervical cancer.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Cyperus , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Extratos Vegetais/farmacologia , Neoplasias do Colo do Útero/genética , Apoptose/genética , Ciclo Celular/efeitos dos fármacos , Etanol/química , Feminino , Células HeLa , Humanos , Solventes/química , Neoplasias do Colo do Útero/tratamento farmacológico
17.
Chem Commun (Camb) ; 55(63): 9379-9382, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31317975

RESUMO

Small-molecule natural products have been an essential source of pharmaceuticals to treat human diseases, but very little is known about their behavior inside dynamic, live human cells. Here, we demonstrate the first structure-activity-distribution relationship (SADR) study of complex natural products, the anti-cancer antimycin-type depsipeptides, using the emerging bioorthogonal Stimulated Raman Scattering (SRS) Microscopy. Our results show that the intracellular enrichment and distribution of these compounds are driven by their potency and specific protein targets, as well as the lipophilic nature of compounds.


Assuntos
Antimicina A/análogos & derivados , Antineoplásicos/química , Depsipeptídeos/química , Antimicina A/química , Antimicina A/metabolismo , Antimicina A/farmacologia , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Depsipeptídeos/metabolismo , Depsipeptídeos/farmacologia , Células HeLa , Humanos , Células MCF-7 , Microscopia de Fluorescência , Análise Espectral Raman , Relação Estrutura-Atividade
18.
Biomater Sci ; 7(9): 3609-3613, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31361290

RESUMO

Development of versatile phototheranostics is highly desirable for cancer theranostics. Herein, a novel organic conjugated polymer (named DPP-TT) with excellent optical properties was designed and prepared. Based on single-component DPP-TT, single DPP-TT NPs as versatile phototheranostics were developed by a simple nanoprecipitation method. The obtained NPs exhibited good water solubility, excellent biocompatibility, outstanding photostability, strong NIR-I light absorption, and appropriate NIR-II fluorescence emission. Importantly, such NPs presented high photothermal conversion efficiency. From the investigations performed in vitro and in vivo, it was observed that DPP-TT NPs show remarkable performance for cancer theranostics, benefiting from single 808 nm laser-induced tri-modal (NIR-II fluorescence/photoacoustic/thermal) imaging-guided photothermal therapy.


Assuntos
Nanopartículas/química , Neoplasias/diagnóstico por imagem , Neoplasias/terapia , Fototerapia/métodos , Animais , Materiais Biocompatíveis/química , Células HeLa , Humanos , Hipertermia Induzida , Camundongos , Imagem Multimodal/métodos , Imagem Óptica/métodos , Técnicas Fotoacústicas/métodos , Polímeros/química , Solubilidade , Nanomedicina Teranóstica
19.
Planta Med ; 85(11-12): 1024-1033, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31261420

RESUMO

Halimium halimifolium (Hh) is a shrub used in Algerian folk medicine to treat gastrointestinal pain. An UHPLC-PDA-ESI/MSn method was developed to identify the metabolic profile of the traditionally used infusion (Hh-A) from the aerial parts. The structures of flavanols were confirmed by NMR analysis after the isolation procedure from a hydrohalcolic extract (Hh-B) that also allowed for the identification of phenolic acids, an aryl butanol glucoside, and different derivatives of quercetin, myricetin, and kaempferol. Tiliroside isomers were the chemical markers of Hh-A and Hh-B (54.33 and 36.00 mg/g, respectively). Hh-A showed a significant scavenging activity both against the radicals 1,1-diphenyl-2-picrylhydrazyl and 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (EC50 = 10.49 µg/mL and TEAC value = 1.98 mM Trolox/mg infusion) and the lipopolysaccharide-induced reactive oxygen species release in A375 and HeLa cells. Moreover, the antihyperglycemic properties, by inhibiting the α-amylase and α-glucosidase enzymes (IC50 = 0.82 mg/mL and 25.01 µg/mL, respectively), were demonstrated. To upgrade the therapeutic effect, a microencapsulation process is proposed as a strategy to optimize stability, handling, and delivery of bioactive components, avoiding the degradation and loss of the biological efficacy after oral intake. Hh-loaded microparticles were designed using cellulose acetate phthalate as the enteric coating material and spray drying as a production process. The results showed a satisfactory process yield (67.9%), encapsulation efficiency (96.7%), and micrometric characteristics of microparticles (laser-scattering, fluorescent, and scanning electron microscopy). In vitro dissolution studies (USPII-pH change method) showed that Hh-loaded microparticles are able to prevent the release and degradation of the bioactive components in the gastric tract, releasing them into the intestinal environment.


Assuntos
Cistaceae/química , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Linhagem Celular , Cistaceae/metabolismo , Suplementos Nutricionais , Composição de Medicamentos , Células HeLa , Humanos , Hipoglicemiantes/isolamento & purificação , Hipoglicemiantes/farmacologia , Espectroscopia de Ressonância Magnética , Medicina Tradicional Africana , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Plantas Medicinais/metabolismo
20.
Nat Commun ; 10(1): 2954, 2019 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-31273204

RESUMO

PARP-1 is rapidly recruited and activated by DNA double-strand breaks (DSBs). Upon activation, PARP-1 synthesizes a structurally complex polymer composed of ADP-ribose units that facilitates local chromatin relaxation and the recruitment of DNA repair factors. Here, we identify a function for PARP-1 in DNA DSB resection. Remarkably, inhibition of PARP-1 leads to hyperresected DNA DSBs. We show that loss of PARP-1 and hyperresection are associated with loss of Ku, 53BP1 and RIF1 resection inhibitors from the break site. DNA curtains analysis show that EXO1-mediated resection is blocked by PARP-1. Furthermore, PARP-1 abrogation leads to increased DNA resection tracks and an increase of homologous recombination in cellulo. Our results, therefore, place PARP-1 activation as a critical early event for DNA DSB repair activation and regulation of resection. Hence, our work has direct implications for the clinical use and effectiveness of PARP inhibition, which is prescribed for the treatment of various malignancies.


Assuntos
Quebras de DNA de Cadeia Dupla , DNA/metabolismo , Poli(ADP-Ribose) Polimerases/metabolismo , Animais , Cromatina/metabolismo , Técnicas de Silenciamento de Genes , Células HeLa , Recombinação Homóloga/genética , Humanos , Camundongos , Modelos Biológicos , Proteínas Nucleares/metabolismo , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Proteínas de Ligação a Telômeros/metabolismo , Proteína 1 de Ligação à Proteína Supressora de Tumor p53/metabolismo
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