Antitumor activity of orally bioavailable farnesyltransferase inhibitor, ABT-100, is mediated by antiproliferative, proapoptotic, and antiangiogenic effects in xenograft models.
Clin Cancer Res
; 11(8): 3045-54, 2005 Apr 15.
Article
em En
| MEDLINE
| ID: mdl-15837760
ABSTRACT
PURPOSE:
To evaluate the preclinical pharmacokinetics, antitumor efficacy, and mechanism of action of a novel orally active farnesyltransferase inhibitor, ABT-100. EXPERIMENTALDESIGN:
In vitro sensitivity of a panel of human cell lines was determined using proliferation and clonogenic assays. In vivo efficacy of ABT-100 was evaluated in xenograft models (flank or orthotopic) by assessing angiogenesis, proliferation, and apoptosis in correlation with pharmacokinetics. Efficacy of the racemate of ABT-100 (A-367074) was also compared with R115777 (tipifarnib).RESULTS:
ABT-100 inhibited proliferation of cells in vitro carrying oncogenic H-Ras (EJ-1 bladder; IC(50) 2.2 nmol/L), Ki-Ras (DLD-1 colon, MDA-MB-231 breast, HCT-116 colon, and MiaPaCa-2 pancreatic; IC(50) range, 3.8-9.2 nmol/L), and wild-type Ras (PC-3 and DU-145; IC(50), 70 and 818 nmol/L, respectively) as well as clonogenic potential. ABT-100 shows 70% to 80% oral bioavailability in mice. ABT-100 regressed EJ-1 tumors (2-12.5 mg/kg/d s.c., every day for 21 days) and showed significant efficacy in DLD-1, LX-1, MiaPaCa-2, or PC-3 tumor-bearing mice (6.25-50 mg/kg/d s.c. once daily or twice daily orally). A-367074 showed equivalent efficacy to R115777 given at approximately one-fourth the total dose of R115777 for a shorter duration (EJ-1 and LX-1). Antitumor activity was associated with decreased cell proliferation (Ki-67), increased apoptosis (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling), and decreased angiogenesis. A reduction in tumor angiogenic cytokine levels (vascular endothelial growth factor, basic fibroblast growth factor, and interleukin-8) correlated with a reduction in tumor vascularity (CD31).CONCLUSIONS:
Overall, ABT-100 has an acceptable pharmacokinetic profile, is well tolerated, and possesses broad-spectrum antitumor activity against a series of xenograft models similar to farnesyltransferase inhibitors in clinical development; therefore, it is an attractive candidate for clinical evaluation.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Apoptose
/
Alquil e Aril Transferases
/
Inibidores da Angiogênese
/
Ensaios Antitumorais Modelo de Xenoenxerto
/
Imidazóis
/
Antineoplásicos
Tipo de estudo:
Prognostic_studies
Limite:
Animals
/
Humans
/
Male
Idioma:
En
Revista:
Clin Cancer Res
Assunto da revista:
NEOPLASIAS
Ano de publicação:
2005
Tipo de documento:
Article
País de afiliação:
Estados Unidos