Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Cancers (Basel) ; 13(23)2021 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-34884992

RESUMO

The integration of cellular status with metabolism is critically important and the coupling of energy production and cellular function is highly evolutionarily conserved. This has been demonstrated in stem cell biology, organismal, cellular and tissue differentiation and in immune cell biology. However, a molecular mechanism delineating how cells coordinate and couple metabolism with transcription as they navigate quiescence, growth, proliferation, differentiation and migration remains in its infancy. The extreme N-termini of the Kat3 coactivator family members, CBP and p300, by far the least homologous regions with only 66% identity, interact with members of the nuclear receptor family, interferon activated Stat1 and transcriptionally competent ß-catenin, a critical component of the Wnt signaling pathway. We now wish to report based on multiomic and functional investigations, utilizing p300 knockdown, N-terminal p300 edited and p300 S89A edited cell lines and p300 S89A knockin mice, that the N-termini of the Kat3 coactivators provide a highly evolutionarily conserved hub to integrate multiple signaling cascades to coordinate cellular metabolism with the regulation of cellular status and function.

2.
Cell Death Discov ; 6: 67, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32793397

RESUMO

Development of novel therapeutic strategies to eradicate malignant tumors is of paramount importance in cancer research. In a recent study, we have introduced a facile protocol for the preparation of corrole-protein nanoparticles (NPs). These NPs consist of a corrole-core coated with protein. We now report that a novel lipophilic corrole, (2)Ga, delivered as human serum albumin (HSA)-coated NPs, displayed antineoplastic activity towards human prostate cancer DU-145 cells. Cryo-TEM analysis of these NPs revealed an average diameter of 50.2 ± 8.1 nm with a spherical architecture exhibiting low polydispersity. In vitro cellular uptake of (2)Ga/albumin NPs was attributable to rapid internalization of the corrole through ligand binding-dependent extracellular release and intercalation of the corrole cargo into the lipid bilayer of the plasma membrane. This finding is in contrast with a previously reported study on corrole-protein NPs that displayed cellular uptake via endocytosis. Investigation of the non-light-induced mechanism of action of (2)Ga suggested the induction of necrosis through plasma membrane destabilization, impairment of calcium homeostasis, lysosomal stress and rupture, as well as formation of reactive oxygen species (ROS). (2)Ga also exhibited potent light-induced cytotoxicity through ROS generation. These findings demonstrate a rapid cellular uptake of (2)Ga/protein NPs along with targeted induction of tumor cell necrosis.

3.
Inorg Chem ; 58(15): 10287-10294, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31335126

RESUMO

In aqueous media, hydrophobic metallocorroles form nanoparticles that are potential theranostic anticancer agents. We have analyzed the electronic and Raman spectra of Al(III), Ga(III), and Au(III) corrole nanoparticles (and made comparisons with DFT-validated assignments of the IR spectra of corresponding monomers) in order to estimate the strengths of corrole-corrole electronic couplings in these assemblies. We find that these spectra are virtually unchanged upon aggregation, confirming that the intermolecular interactions in these nanoparticles are very weak.

4.
Sci Rep ; 9(1): 2294, 2019 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-30783138

RESUMO

Recent work has highlighted the potential of metallocorroles as versatile platforms for the development of drugs and imaging agents, since the bioavailability, physicochemical properties and therapeutic activity can be dramatically altered by metal ion substitution and/or functional group replacement. Significant advances in cancer treatment and imaging have been reported based on work with a water-soluble bis-sulfonated gallium corrole in both cellular and rodent-based models. We now show that cytotoxicities increase in the order Ga < Fe < Al < Mn < Sb < Au for bis-sulfonated corroles; and, importantly, that they correlate with metallocorrole affinities for very low density lipoprotein (VLDL), the main carrier of lipophilic drugs. As chemotherapeutic potential is predicted to be enhanced by increased lipophilicity, we have developed a novel method for the preparation of cell-penetrating lipophilic metallocorrole/serum-protein nanoparticles (NPs). Cryo-TEM revealed an average core metallocorrole particle size of 32 nm, with protein tendrils extending from the core (conjugate size is ~100 nm). Optical imaging of DU-145 prostate cancer cells treated with corrole NPs (≤100 nM) revealed fast cellular uptake, very slow release, and distribution into the endoplasmic reticulum (ER) and lysosomes. The physical properties of corrole NPs prepared in combination with transferrin and albumin were alike, but the former were internalized to a greater extent by the transferrin-receptor-rich DU-145 cells. Our method of preparation of corrole/protein NPs may be generalizable to many bioactive hydrophobic molecules to enhance their bioavailability and target affinity.


Assuntos
Nanopartículas/química , Nanopartículas/metabolismo , Porfirinas/química , Linhagem Celular Tumoral , Cromatografia Gasosa , Cromatografia Líquida de Alta Pressão , Microscopia Crioeletrônica , Retículo Endoplasmático/metabolismo , Citometria de Fluxo , Humanos , Peróxido de Hidrogênio/química , Lisossomos/metabolismo , Espectroscopia de Ressonância Magnética , Masculino , Microscopia de Força Atômica , Microscopia Eletroquímica de Varredura , Nanopartículas/ultraestrutura , Oxirredução , Sulfetos/química
5.
Int J Mol Sci ; 19(2)2018 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-29385725

RESUMO

Cancers that exhibit the Warburg effect may elevate expression of glyoxylase 1 (GLO1) to detoxify the toxic glycolytic byproduct methylglyoxal (MG) and inhibit the formation of pro-apoptotic advanced glycation endproducts (AGEs). Inhibition of GLO1 in cancers that up-regulate glycolysis has been proposed as a therapeutic targeting strategy, but this approach has not been evaluated for glioblastoma multiforme (GBM), the most aggressive and difficult to treat malignancy of the brain. Elevated GLO1 expression in GBM was established in patient tumors and cell lines using bioinformatics tools and biochemical approaches. GLO1 inhibition in GBM cell lines and in an orthotopic xenograft GBM mouse model was examined using both small molecule and short hairpin RNA (shRNA) approaches. Inhibition of GLO1 with S-(p-bromobenzyl) glutathione dicyclopentyl ester (p-BrBzGSH(Cp)2) increased levels of the DNA-AGE N²-1-(carboxyethyl)-2'-deoxyguanosine (CEdG), a surrogate biomarker for nuclear MG exposure; substantially elevated expression of the immunoglobulin-like receptor for AGEs (RAGE); and induced apoptosis in GBM cell lines. Targeting GLO1 with shRNA similarly increased CEdG levels and RAGE expression, and was cytotoxic to glioma cells. Mice bearing orthotopic GBM xenografts treated systemically with p-BrBzGSH(Cp)2 exhibited tumor regression without significant off-target effects suggesting that GLO1 inhibition may have value in the therapeutic management of these drug-resistant tumors.


Assuntos
Neoplasias Encefálicas , Inibidores Enzimáticos/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioblastoma , Lactoilglutationa Liase , Proteínas de Neoplasias , Receptor para Produtos Finais de Glicação Avançada/biossíntese , Animais , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Glioblastoma/tratamento farmacológico , Glioblastoma/metabolismo , Glioblastoma/patologia , Xenoenxertos , Humanos , Lactoilglutationa Liase/antagonistas & inibidores , Lactoilglutationa Liase/metabolismo , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/metabolismo , Transplante de Neoplasias , Ensaios Antitumorais Modelo de Xenoenxerto
6.
Chem Res Toxicol ; 30(2): 689-698, 2017 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-28107623

RESUMO

More precise identification and treatment monitoring of prediabetic/diabetic individuals will require additional biomarkers to complement existing diagnostic tests. Candidates include hyperglycemia-induced adducts such as advanced glycation end products (AGEs) of proteins, lipids, and DNA. The potential for DNA-AGEs as diabetic biomarkers was examined in a longitudinal study using the Leprdb/db animal model of metabolic syndrome. The DNA-AGE, N2-(1-carboxyethyl)-2'-deoxyguanosine (CEdG) was quantified by mass spectrometry using isotope dilution from the urine and tissue of hyperglycemic and normoglycemic mice. Hyperglycemic mice (fasting plasma glucose, FPG, ≥ 200 mg/dL) displayed a higher median urinary CEdG value (238.4 ± 112.8 pmol/24 h) than normoglycemic mice (16.1 ± 11.8 pmol/24 h). Logistic regression analysis revealed urinary CEdG to be an independent predictor of hyperglycemia. Urinary CEdG was positively correlated with FPG in hyperglycemic animals and with HbA1c for all mice. Average tissue-derived CEdG was also higher in hyperglycemic mice (18.4 CEdG/106 dG) than normoglycemic mice (4.4 CEdG/106 dG). Urinary CEdG was significantly elevated in Leprdb/db mice relative to Leprwt/wt, and tissue CEdG values increased in the order Leprwt/wt < Leprwt/db < Leprdb/db. These data suggest that urinary CEdG measurement may provide a noninvasive quantitative index of glycemic status and augment existing biomarkers for the diagnosis and monitoring of diabetes.


Assuntos
DNA/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Modelos Animais de Doenças , Produtos Finais de Glicação Avançada/metabolismo , Animais , Camundongos , Camundongos Endogâmicos C57BL
7.
Proc Natl Acad Sci U S A ; 113(16): E2258-66, 2016 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-27044076

RESUMO

We report derivatives of gallium(III) tris(pentafluorophenyl)corrole, 1 [Ga(tpfc)], with either sulfonic (2) or carboxylic acids (3, 4) as macrocyclic ring substituents: the aminocaproate derivative, 3 [Ga(ACtpfc)], demonstrated high cytotoxic activity against all NCI60 cell lines derived from nine tumor types and confirmed very high toxicity against melanoma cells, specifically the LOX IMVI and SK-MEL-28 cell lines. The toxicities of 1, 2, 3, and 4 [Ga(3-ctpfc)] toward prostate (DU-145), melanoma (SK-MEL-28), breast (MDA-MB-231), and ovarian (OVCAR-3) cancer cells revealed a dependence on the ring substituent: IC50values ranged from 4.8 to >200 µM; and they correlated with the rates of uptake, extent of intracellular accumulation, and lipophilicity. Carboxylated corroles 3 and 4, which exhibited about 10-fold lower IC50values (<20 µM) relative to previous analogs against all four cancer cell lines, displayed high efficacy (Emax= 0). Confocal fluorescence imaging revealed facile uptake of functionalized gallium corroles by all human cancer cells that followed the order: 4 >> 3 > 2 >> 1 (intracellular accumulation of gallium corroles was fastest in melanoma cells). We conclude that carboxylated gallium corroles are promising chemotherapeutics with the advantage that they also can be used for tumor imaging.


Assuntos
Antineoplásicos , Gálio , Neoplasias/tratamento farmacológico , Porfirinas , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Gálio/farmacocinética , Gálio/farmacologia , Humanos , Masculino , Neoplasias/metabolismo , Porfirinas/farmacocinética , Porfirinas/farmacologia
8.
J Vis Exp ; (97)2015 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-25867444

RESUMO

Chemotherapy often involves broad-spectrum cytotoxic agents with many side effects and limited targeting. Corroles are a class of tetrapyrrolic macrocycles that exhibit differential cytostatic and cytotoxic properties in specific cell lines, depending on the identities of the chelated metal and functional groups. The unique behavior of functionalized corroles towards specific cell lines introduces the possibility of targeted chemotherapy. Many anticancer drugs are evaluated by their ability to inhibit RNA transcription. Here we present a step-by-step protocol for RNA transcription in the presence of known and potential inhibitors. The evaluation of the RNA products of the transcription reaction by gel electrophoresis and UV-Vis spectroscopy provides information on inhibitive properties of potential anticancer drug candidates and, with modifications to the assay, more about their mechanism of action. Little is known about the molecular mechanism of action of corrole cytotoxicity. In this experiment, we consider two corrole compounds: gallium(III) 5,10,15-(tris)pentafluorophenylcorrole (Ga(tpfc)) and freebase analogue 5,10,15-(tris)pentafluorophenylcorrole (tpfc). An RNA transcription assay was used to examine the inhibitive properties of the corroles. Five transcription reactions were prepared: DNA treated with Actinomycin D, triptolide, Ga(tpfc), tpfc at a [complex]:[template DNA base] ratio of 0.01, respectively, and an untreated control. The transcription reactions were analyzed after 4 hr using agarose gel electrophoresis and UV-Vis spectroscopy. There is clear inhibition by Ga(tpfc), Actinomycin D, and triptolide. This RNA transcription assay can be modified to provide more mechanistic detail by varying the concentrations of the anticancer complex, DNA, or polymerase enzyme, or by incubating the DNA or polymerase with the complexes prior to RNA transcription; these modifications would differentiate between an inhibition mechanism involving the DNA or the enzyme. Adding the complex after RNA transcription can be used to test whether the complexes degrade or hydrolyze the RNA. This assay can also be used to study additional anticancer candidates.


Assuntos
Complexos de Coordenação/farmacologia , Ensaios Enzimáticos/métodos , Gálio/farmacologia , Metaloporfirinas/farmacologia , Neoplasias/tratamento farmacológico , RNA/genética , Transcrição Gênica/efeitos dos fármacos , Linhagem Celular Tumoral , Complexos de Coordenação/química , Feminino , Gálio/química , Humanos , Masculino , Metaloporfirinas/química , Neoplasias/enzimologia , Neoplasias/genética , RNA/química , Espectrofotometria Ultravioleta
9.
Chem Commun (Camb) ; 50(89): 13789-92, 2014 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-25252099

RESUMO

We have synthesized and characterized a water-soluble gold(III) corrole (1-Au) that is highly toxic to cisplatin-resistant cancer cells. Relative to its 1-Ga analogue, axial ligands bind only weakly to 1-Au, which likely accounts for its lower affinity for human serum albumin (HSA). We suggest that the cytotoxicity of 1-Au may be related to this lower HSA affinity.


Assuntos
Antineoplásicos , Ouro , Compostos Organoáuricos , Porfirinas , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Citostáticos/química , Citostáticos/farmacologia , Citotoxinas/química , Citotoxinas/farmacologia , Gálio/química , Gálio/farmacologia , Ouro/química , Ouro/farmacologia , Humanos , Compostos Organoáuricos/química , Compostos Organoáuricos/farmacologia , Porfirinas/química , Porfirinas/farmacologia , Albumina Sérica/química , Albumina Sérica/metabolismo
10.
Chem Res Toxicol ; 25(2): 400-9, 2012 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-22185566

RESUMO

A gallium(III)-substituted amphiphilic corrole noncovalently associated with a targeting protein was previously found by us to confer promising cytotoxic and antitumor activities against a breast cancer cell line and a mouse xenograft breast cancer model. To further explore potential anticancer applications, the cytostatic and cytotoxic properties of six nontargeted metallocorroles were evaluated against seven human cancer cell lines. Results indicated that toxicity toward human cancer cells depended on the metal ion as well as corrole functional group substitution. Ga(III)-substituted metallocorrole 1-Ga inhibited proliferation of breast (MDA-MB-231), melanoma (SK-MEL-28), and ovarian (OVCAR-3) cancer cells primarily by arrest of DNA replication, whereas 2-Mn displayed both cytostatic and cytotoxic properties. Confocal microscopy revealed extensive uptake of 1-Ga into the cytoplasm of melanoma and ovarian cancer cells, while prostate cancer cells (DU-145) displayed extensive nuclear localization. The localization of 1-Ga to the nucleus in DU-145 cells was exploited to achieve a 3-fold enhancement in the IC(50) of doxorubicin upon coadministration. Time-course studies showed that over 90% of melanoma cells incubated with 30 µM 1-Ga internalized metallocorrole after 15 min. Cellular uptake of 1-Ga and 1-Al was fastest and most efficient in melanoma, followed by prostate and ovarian cancer cells. Cell cycle analyses revealed that bis-sulfonated corroles containing Al(III), Ga(III), and Mn(III) induced late M phase arrest in several different cancer cell lines, a feature that could be developed for potential therapeutic benefit.


Assuntos
Citostáticos/toxicidade , Citotoxinas/toxicidade , Metais/química , Compostos Organometálicos/toxicidade , Porfirinas/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Citostáticos/química , Citotoxinas/química , Desenho de Fármacos , Humanos , Neoplasias/tratamento farmacológico
11.
Biochemistry ; 50(12): 2321-9, 2011 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-21355561

RESUMO

Glycation of biopolymers by glucose-derived α-oxo-aldehydes such as methylglyoxal (MG) is believed to play a major role in the complex pathologies associated with diabetes and metabolic disease. In contrast to the extensive literature detailing the formation and physiological consequences of protein glycation, there is little information about the corresponding phenomenon for DNA. To assess the potential contribution of DNA glycation to genetic instability, we prepared shuttle vectors containing defined levels of the DNA glycation adduct N(2)-(1-carboxyethyl)-2'-deoxyguanosine (CEdG) and transfected them into isogenic human fibroblasts that differed solely in the capacity to conduct nucleotide excision repair (NER). In the NER-compromised fibroblasts, the induced mutation frequencies increased up to 18-fold relative to background over a range of ∼10-1400 CEdG adducts/10(5) dG, whereas the same substrates transfected into NER-competent cells induced a response that was 5-fold over background at the highest adduct density. The positive linear correlation (R(2) = 0.998) of mutation frequency with increasing CEdG level in NER-defective cells suggested that NER was the primary if not exclusive mechanism for repair of this adduct in human fibroblasts. Consistent with predictions from biochemical studies using CEdG-substituted oligonucleotides, guanine transversions were the predominant mutation resulting from replication of MG-modified plasmids. At high CEdG levels, significant increases in the number of AT → GC transitions were observed exclusively in NER-competent cells (P < 0.0001). This suggested the involvement of an NER-dependent mutagenic process in response to critical levels of DNA damage, possibly mediated by error-prone Y-family polymerases.


Assuntos
Adutos de DNA/genética , Adutos de DNA/metabolismo , Reparo do DNA , Desoxiguanosina/análogos & derivados , Fibroblastos/metabolismo , Produtos Finais de Glicação Avançada/metabolismo , Mutagênese , Sequência de Bases , Desoxiguanosina/metabolismo , Genes Supressores , Humanos , Mutação , Plasmídeos/genética , RNA de Transferência/genética
12.
Biochemistry ; 43(49): 15339-48, 2004 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-15581346

RESUMO

Endogenous DNA damage induced by lipid peroxidation is believed to play a critical role in carcinogenesis. Lipid peroxidation generates free radical intermediates (primarily peroxyl radicals, ROO(*)) and electrophilic aldehydes as the principal genotoxicants. Although detailed information is available on the role of aldehyde base adducts in mutagenesis and carcinogenesis, the contribution of peroxyl radical mediated DNA base damage is less well understood. In the present study we have mapped oxidative base damage induced by peroxyl radicals in the supF tRNA gene and correlated this information with peroxidation-induced mutations in several human fibroblast cell lines. Nearly identical patterns of oxidative base damage were obtained from reaction of DNA with either peroxidizing arachidonic acid (20:4omega6) or peroxyl radicals generated by thermolysis of ABIP in the presence of oxygen. Oxidative base damage primarily occurred at G and C. Transversions at GC base pairs in the supF gene were the major base substitution detected in all cell lines. Peroxyl radical induced tandem mutations were also observed. Many mutation hot spots coincided with sites of mapped oxidative lesions, although in some cases hot spots occurred adjacent to the damaged base. Evidence is presented for the involvement of 8-oxodG in the oxidation of DNA by ROO(*). These results are used to interpret some key features of previously published mutation spectra induced by lipid peroxidation in human cells.


Assuntos
Dano ao DNA , DNA Bacteriano/metabolismo , Guanina/análogos & derivados , Peroxidação de Lipídeos/genética , Mutagênese , Peróxidos/toxicidade , Ácido Araquidônico/toxicidade , Compostos Azo/toxicidade , Sequência de Bases/efeitos dos fármacos , Linhagem Celular Transformada , Análise Mutacional de DNA , Radicais Livres/toxicidade , Cromatografia Gasosa-Espectrometria de Massas , Genes Supressores , Guanina/metabolismo , Humanos , Imidazóis/toxicidade , Estresse Oxidativo , Oxigênio/toxicidade , RNA de Transferência/genética , RNA de Transferência/metabolismo
13.
Biochemistry ; 42(51): 15036-44, 2003 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-14690412

RESUMO

Endogenous cellular oxidation of omega6-polyunsaturated fatty acids (PUFAs) has long been recognized as a contributing factor in the development of various cancers. The accrual of DNA damage as a result of reaction with free radical and electrophilic aldehyde products of lipid peroxidation is believed to be involved; however, the genotoxic and mutation-inducing potential of specific membrane PUFAs remains poorly defined. In the present study we have examined the ability of peroxidizing arachidonic acid (AA, 20:4omega6) to induce DNA strand breaks, base modifications, and mutations. The time-dependent induction of single-strand breaks and oxidative base modifications by AA in genomic DNA was quantified using denaturing glyoxal gel electrophoresis. Mutation spectra were determined in XP-G fibroblasts and a repair-proficient line corrected for this defect by c-DNA complementation (XP-G(+)). Mutation frequencies were elevated from approximately 5- to 30-fold over the background following reaction of DNA with AA for various times. The XPG gene product was found to be involved in the suppression of mutations after extended reaction of DNA with AA. Arachidonic acid-induced base substitutions were consistent with the presence of both oxidized and aldehyde base adducts in DNA. The frequency of multiple-base substitutions induced by AA was significantly reduced upon correction for the XPG defect (14% vs 2%, P = 0.0015). Evidence is also presented which suggests that the induced frequency of multiple mutations is lesion dependent. These results are compared to published data for mutations stimulated by alpha,beta-unsaturated aldehydes identified as products of lipid peroxidation.


Assuntos
Ácido Araquidônico/química , Dano ao DNA , Peroxidação de Lipídeos/genética , Mutação , Ácido Araquidônico/metabolismo , Ácido Araquidônico/toxicidade , Sequência de Bases , Linhagem Celular , Quebra Cromossômica/genética , DNA/química , DNA/genética , DNA/metabolismo , Análise Mutacional de DNA , Reparo do DNA/genética , Eletroforese em Gel de Ágar , Radicais Livres/química , Radicais Livres/metabolismo , Teste de Complementação Genética , Humanos , Dados de Sequência Molecular , Conformação de Ácido Nucleico , Oxirredução , Deleção de Sequência/genética , Xeroderma Pigmentoso/genética , Xeroderma Pigmentoso/metabolismo , Xeroderma Pigmentoso/patologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...