A lack of detectable modification of topoisomerase II activity in a series of human tumor cell lines expressing only low levels of etoposide resistance.
Int J Cancer
; 47(6): 899-902, 1991 Apr 01.
Article
em En
| MEDLINE
| ID: mdl-1849124
ABSTRACT
Etoposide (VP-16) resistance is expressed following in vitro exposure of HN-1 and MCF-7 human tumor cells to the drug itself or to fractionated X irradiation. VP-16-selected sublines prove cross-resistant to Adriamycin, amsacrine and actinomycin D, whilst X-ray-pretreated sublines show cross-resistance to only actinomycin D. These differential responses, in the HN-1 series, are not associated with significant differences in amounts of immunoreactive topoisomerase (topo) II, altered topo-II catalytic activity of nuclear extracts or changes in susceptibility of the topo II to VP-16- or amsacrine-induced DNA-protein cross-link formation. Therefore significant modifications in topo II appear not to be implicated in VP-16 resistance in these HN-1 sublines.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Dano ao DNA
/
DNA Topoisomerases Tipo II
/
Etoposídeo
Limite:
Female
/
Humans
Idioma:
En
Revista:
Int J Cancer
Ano de publicação:
1991
Tipo de documento:
Article
País de afiliação:
Reino Unido