Cyclopentenyl cytosine increases gemcitabine radiosensitisation in human pancreatic cancer cells.
Br J Cancer
; 98(7): 1226-33, 2008 Apr 08.
Article
en En
| MEDLINE
| ID: mdl-18349845
The deoxycytidine analogue 2',2'-difluoro-2'-deoxycytidine (dFdC, gemcitabine) is a potent radiosensitiser, but has limited efficacy in combination with radiotherapy in patients with pancreatic cancer due to acute toxicity. We investigated whether cyclopentenyl cytosine (CPEC), targetting the 'de novo' biosynthesis of cytidine triphosphate (CTP), could increase dFdC cytotoxicity alone or in combination with irradiation in a panel of human pancreatic cancer cells (Panc-1, Miapaca-2, BxPC-3). To investigate the role of deoxycytidine kinase (dCK), the rate-limiting enzyme in the activation of dFdC, human lung cancer cells without (dFdC-resistant SWg) and with an intact dCK gene (dFdC-sensitive SWp) were included. We found that CPEC (100-1000 nmol l(-1)) specifically reduced CTP levels in a dose-dependent manner that lasted up to 72 h in all cell lines. Preincubation with CPEC resulted in a dose-dependent increase in dFdC incorporated into the DNA only in dFdC-sensitive cells. Consequently, CPEC increased the effectiveness of dFdC (300 nmol l(-1) for 4 h) only in dFdC-sensitive cells, which was accompanied by an increase in apoptosis. We also found that CPEC enhanced the radiosensitivity of cells treated with dFdC (30-300 nmol l(-1) for 4 h). These results indicate that CPEC enhances the cytotoxicity of dFdC alone and in combination with irradiation in several human tumour cell lines with an intact dCK gene.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Neoplasias Pancreáticas
/
Citidina
/
Desoxicitidina
Límite:
Humans
Idioma:
En
Revista:
Br J Cancer
Año:
2008
Tipo del documento:
Article
País de afiliación:
Países Bajos
Pais de publicación:
Reino Unido