High-content micronucleus assay in genotoxicity profiling: initial-stage development and some applications in the investigative/lead-finding studies in drug discovery.
Toxicol Sci
; 118(1): 71-85, 2010 Nov.
Article
em En
| MEDLINE
| ID: mdl-20631060
ABSTRACT
This article describes the first step toward full (that includes conditions for both absence and presence of metabolic activation) validation and drug discovery application of a 96-well, automated, high-content micronucleus (HCMN) assay. The current validation tests were performed using Chinese hamster ovary cells, in the absence of metabolic activation, against three distinct sets of drug-like compounds that represent all stages of a drug discovery pipeline. A compound categorization scheme was created based on quantitative relationships between micronucleus (MN) signals, cytotoxicity, and compound solubility. Results from initial validation compounds (n = 38) set the stage for differentiating overall positive and negative MN inducers. To delve deeper into the compound categorization process, a more extensive validation set, consisting of a larger set (n = 370) of "drug-like but less optimized" early-stage compounds, was used for further refinement of positive and negative compound categories. The predictivity and applicability of the assay for clinical stage compounds was ascertained using (n = 168) clinically developed marketed drugs or well-studied compounds. Upon full validation, a detailed analysis of results established five compound categories--NEG (negative), NEG/xx µM (negative up to the solubility limit of xx µM), WPOS (weak positive), POS (positive), and INCON (inconclusive). Furthermore, examples of lead-finding applications and ongoing investigative HCMN activities are described. A proposal is offered on how the HCMN assay can be positioned in parallel to the overall stage gates (e.g., scaffold selection, lead optimization, late-stage preclinical development) of drug discovery programs. Because of its greater throughput, 1-week turnaround time, and a substantially reduced (1-2 mg) requirement for compound consumption, the HCMN assay is appropriate for developing structure-genotoxicity relationships and for mechanistic genotoxicity studies. The assay does not replace the Organization for Economic Cooperation and Development-compliant, non-good laboratory practice in vitro MN test (e.g., slide-based MN test in TK6 lymphoblastoid cells) that is used for full characterization of lead candidates.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Perfilação da Expressão Gênica
/
Indústria Farmacêutica
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Avaliação Pré-Clínica de Medicamentos
/
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos
Tipo de estudo:
Diagnostic_studies
/
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Toxicol Sci
Assunto da revista:
TOXICOLOGIA
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Estados Unidos