Concomitant expression of E. coli cytosine deaminase and uracil phosphoribosyltransferase improves the cytotoxicity of 5-fluorocytosine.
FEMS Microbiol Lett
; 167(1): 41-9, 1998 Oct 01.
Article
en En
| MEDLINE
| ID: mdl-9785450
ABSTRACT
The prodrug activation system formed by the E. coli codA gene encoding cytosine deaminase (CD) and 5-fluorocytosine (5-FC) developed for selective cancer chemotherapy suffers from a sensitivity limitation in many tumour cells. In an attempt to improve the CD/5-FC suicide association, we combined the E. coli upp gene encoding uracil phosphoribosyltransferase (UPRT) with codA gene to create the situation prevailing in E. coli, a bacterium very efficient in metabolising 5-FC. The constitutive expression of the two genes cloned on an E. coli-animal cell shuttle plasmid either in a linked or in a fused configuration was evaluated in E. coli strains selected and engineered to mimic the 5-FC metabolism encountered in mammalian cells. The simultaneous expression of codA and upp genes generated a cooperative effect resulting in a dramatic increase in 5-FC sensitivity of cells compared to the expression of codA alone. Furthermore, it was shown that the association of UPRT with CD facilitated the uptake of 5-FC, in the situation where the drug penetrates cells by passive diffusion as in mammalian cells, by directly channeling 5-fluorouracil, the product of CD, to 5-fluoroUMP, the product of UPRT.
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Colección:
01-internacional
Asunto principal:
Pentosiltransferasa
/
Proteínas de Escherichia coli
/
Escherichia coli
/
Flucitosina
/
Genes Bacterianos
/
Nucleósido Desaminasas
Límite:
Animals
Idioma:
En
Revista:
FEMS Microbiol Lett
Año:
1998
Tipo del documento:
Article
País de afiliación:
Francia