Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Int J Cancer ; 152(7): 1399-1413, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-36346110

RESUMO

The mitochondrion is a gatekeeper of apoptotic processes, and mediates drug resistance to several chemotherapy agents used to treat cancer. Neuroblastoma is a common solid cancer in young children with poor clinical outcomes following conventional chemotherapy. We sought druggable mitochondrial protein targets in neuroblastoma cells. Among mitochondria-associated gene targets, we found that high expression of the mitochondrial adenine nucleotide translocase 2 (SLC25A5/ANT2), was a strong predictor of poor neuroblastoma patient prognosis and contributed to a more malignant phenotype in pre-clinical models. Inhibiting this transporter with PENAO reduced cell viability in a panel of neuroblastoma cell lines in a TP53-status-dependant manner. We identified the histone deacetylase inhibitor, suberanilohydroxamic acid (SAHA), as the most effective drug in clinical use against mutant TP53 neuroblastoma cells. SAHA and PENAO synergistically reduced cell viability, and induced apoptosis, in neuroblastoma cells independent of TP53-status. The SAHA and PENAO drug combination significantly delayed tumour progression in pre-clinical neuroblastoma mouse models, suggesting that these clinically advanced inhibitors may be effective in treating the disease.


Assuntos
Translocador 2 do Nucleotídeo Adenina , Antineoplásicos , Inibidores de Histona Desacetilases , Ácidos Hidroxâmicos , Neuroblastoma , Animais , Camundongos , Antineoplásicos/farmacologia , Apoptose , Linhagem Celular Tumoral , Inibidores de Histona Desacetilases/farmacologia , Histonas/metabolismo , Ácidos Hidroxâmicos/uso terapêutico , Mitocôndrias/metabolismo , Neuroblastoma/tratamento farmacológico , Vorinostat/farmacologia , Translocador 2 do Nucleotídeo Adenina/antagonistas & inibidores
2.
Pharmaceuticals (Basel) ; 14(12)2021 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-34959631

RESUMO

PR-104 is a phosphate ester pre-prodrug that is converted in vivo to its cognate alcohol, PR-104A, a latent alkylator which forms potent cytotoxins upon bioreduction. Hypoxia selectivity results from one-electron nitro reduction of PR-104A, in which cytochrome P450 oxidoreductase (POR) plays an important role. However, PR-104A also undergoes 'off-target' two-electron reduction by human aldo-keto reductase 1C3 (AKR1C3), resulting in activation in oxygenated tissues. AKR1C3 expression in human myeloid progenitor cells probably accounts for the dose-limiting myelotoxicity of PR-104 documented in clinical trials, resulting in human PR-104A plasma exposure levels 3.4- to 9.6-fold lower than can be achieved in murine models. Structure-based design to eliminate AKR1C3 activation thus represents a strategy for restoring the therapeutic window of this class of agent in humans. Here, we identified SN29176, a PR-104A analogue resistant to human AKR1C3 activation. SN29176 retains hypoxia selectivity in vitro with aerobic/hypoxic IC50 ratios of 9 to 145, remains a substrate for POR and triggers γH2AX induction and cell cycle arrest in a comparable manner to PR-104A. SN35141, the soluble phosphate pre-prodrug of SN29176, exhibited superior hypoxic tumour log cell kill (>4.0) to PR-104 (2.5-3.7) in vivo at doses predicted to be achievable in humans. Orthologues of human AKR1C3 from mouse, rat and dog were incapable of reducing PR-104A, thus identifying an underlying cause for the discrepancy in PR-104 tolerance in pre-clinical models versus humans. In contrast, the macaque AKR1C3 gene orthologue was able to metabolise PR-104A, indicating that this species may be suitable for evaluating the toxicokinetics of PR-104 analogues for clinical development. We confirmed that SN29176 was not a substrate for AKR1C3 orthologues across all four pre-clinical species, demonstrating that this prodrug analogue class is suitable for further development. Based on these findings, a prodrug candidate was subsequently identified for clinical trials.

3.
Nat Commun ; 12(1): 1881, 2021 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-33767157

RESUMO

To achieve the very high oncoprotein levels required to drive the malignant state cancer cells utilise the ubiquitin proteasome system to upregulate transcription factor levels. Here our analyses identify ALYREF, expressed from the most common genetic copy number variation in neuroblastoma, chromosome 17q21-ter gain as a key regulator of MYCN protein turnover. We show strong co-operativity between ALYREF and MYCN from transgenic models of neuroblastoma in vitro and in vivo. The two proteins form a nuclear coactivator complex which stimulates transcription of the ubiquitin specific peptidase 3, USP3. We show that increased USP3 levels reduce K-48- and K-63-linked ubiquitination of MYCN, thus driving up MYCN protein stability. In the MYCN-ALYREF-USP3 signal, ALYREF is required for MYCN effects on the malignant phenotype and that of USP3 on MYCN stability. This data defines a MYCN oncoprotein dependency state which provides a rationale for future pharmacological studies.


Assuntos
Carcinogênese/patologia , Proteína Proto-Oncogênica N-Myc/metabolismo , Neuroblastoma/patologia , Proteínas Nucleares/metabolismo , Proteínas de Ligação a RNA/metabolismo , Fatores de Transcrição/metabolismo , Proteases Específicas de Ubiquitina/metabolismo , Animais , Carcinogênese/genética , Linhagem Celular Tumoral , Sobrevivência Celular/genética , Cromossomos Humanos Par 17/genética , Variações do Número de Cópias de DNA/genética , Células HEK293 , Humanos , Camundongos , Proteína Proto-Oncogênica N-Myc/genética , Neuroblastoma/genética , Proteínas Nucleares/genética , Prognóstico , Interferência de RNA , RNA Interferente Pequeno/genética , Proteínas de Ligação a RNA/genética , Fatores de Transcrição/genética , Transcrição Gênica/genética , Ativação Transcricional/genética , Proteases Específicas de Ubiquitina/genética , Ubiquitinação/fisiologia
4.
Oncogene ; 40(13): 2367-2381, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33658627

RESUMO

Histone deacetylase (HDAC) inhibitors are effective in MYCN-driven cancers, because of a unique need for HDAC recruitment by the MYCN oncogenic signal. However, HDAC inhibitors are much more effective in combination with other anti-cancer agents. To identify novel compounds which act synergistically with HDAC inhibitor, such as suberanoyl hydroxamic acid (SAHA), we performed a cell-based, high-throughput drug screen of 10,560 small molecule compounds from a drug-like diversity library and identified a small molecule compound (SE486-11) which synergistically enhanced the cytotoxic effects of SAHA. Effects of drug combinations on cell viability, proliferation, apoptosis and colony forming were assessed in a panel of neuroblastoma cell lines. Treatment with SAHA and SE486-11 increased MYCN ubiquitination and degradation, and markedly inhibited tumorigenesis in neuroblastoma xenografts, and, MYCN transgenic zebrafish and mice. The combination reduced ubiquitin-specific protease 5 (USP5) levels and increased unanchored polyubiquitin chains. Overexpression of USP5 rescued neuroblastoma cells from the cytopathic effects of the combination and reduced unanchored polyubiquitin, suggesting USP5 is a therapeutic target of the combination. SAHA and SE486-11 directly bound to USP5 and the drug combination exhibited a 100-fold higher binding to USP5 than individual drugs alone in microscale thermophoresis assays. MYCN bound to the USP5 promoter and induced USP5 gene expression suggesting that USP5 and MYCN expression created a forward positive feedback loop in neuroblastoma cells. Thus, USP5 acts as an oncogenic cofactor with MYCN in neuroblastoma and the novel combination of HDAC inhibitor with SE486-11 represents a novel therapeutic approach for the treatment of MYCN-driven neuroblastoma.


Assuntos
Carcinogênese/efeitos dos fármacos , Inibidores de Histona Desacetilases/farmacologia , Proteína Proto-Oncogênica N-Myc/genética , Neuroblastoma/tratamento farmacológico , Proteases Específicas de Ubiquitina/genética , Proteínas de Peixe-Zebra/genética , Animais , Animais Geneticamente Modificados/genética , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Xenoenxertos , Humanos , Camundongos , Neuroblastoma/genética , Neuroblastoma/patologia , Bibliotecas de Moléculas Pequenas/farmacologia , Vorinostat/farmacologia , Peixe-Zebra/genética
5.
Biochem Pharmacol ; 123: 19-28, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-27729218

RESUMO

The multidrug resistance P-glycoprotein (P-gp) is characterised by the ability to bind and/or transport an astonishing array of drugs. This poly-specificity is imparted by at least four pharmacologically distinct binding sites within the transmembrane domain. Whether or not these sites are spatially distinct has remained unclear. Biochemical and structural investigations have implicated a central cavity as the likely location for the binding sites. In the present investigation, a number of contact residues that are involved in drug binding were identified through biochemical assays using purified, reconstituted P-gp. Drugs were selected to represent each of the four pharmacologically distinct sites. Contact residues important in rhodamine123 binding were identified in the central cavity of P-gp. However, contact residues for the binding of vinblastine, paclitaxel and nicardipine were located at the lipid-protein interface rather than the central cavity. A key residue (F978) within the central cavity is believed to be involved in coupling drug binding to nucleotide hydrolysis. Data observed in this investigation suggest the presence of spatially distinct drug binding sites connecting through to a single translocation pore in the central cavity.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Animais , Sítios de Ligação , Meios de Cultura , Eletroforese em Gel de Poliacrilamida , Humanos , Mariposas , Mutagênese Sítio-Dirigida , Nicardipino/metabolismo , Paclitaxel/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Rodamina 123/metabolismo , Vimblastina/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA