RESUMO
A set of multidrug resistant (MDR) murine leukemia P388 sublines processing 30-50-fold mdr1 gene amplification was obtained as a result of experimental chemotherapy with rubomycin, ruboxyl, vinblastine, vincristine, or combination of rubomycin and vincristine. Significant differences of developed MDR sublines in response to treatment with cisplatin, tiophosphamide, sarcolysin, and dopad were found. Strong correlation between drug sensitivity and a copy number of gene coding for 19-22 kDa calcium-binding sorcin gene co-amplification were hypersensitive to cisplatin and alkylating agents, the cell sublines showing amplification of sorcin DNA sequences did not possess such collateral sensitivity and even acquired cross-resistance. The dependence of sensitivity to cisplatin on sorcin gene co-amplification was confirmed by analysis of Djungarian hamster DM15 cell sublines that selected for MDR in vitro by colchicine.
Assuntos
Alquilantes/farmacologia , Proteínas de Ligação ao Cálcio/genética , Cisplatino/farmacologia , Resistência a Múltiplos Medicamentos/genética , Amplificação de Genes/genética , Leucemia P388/genética , Proteínas de Neoplasias/genética , Animais , Linhagem Celular Transformada , Cricetinae , Fibroblastos , Leucemia P388/tratamento farmacológicoRESUMO
The method of 31P nuclear magnetic resonance was used to study in vivo the level of phosphorus-containing metabolites in P388 leukemia cells sensitive or resistant to rubomycin (daunomycin) and its nitroxyl analog-emoxyl. It was shown that decreased content of phosphomonoesters (PME) is characteristic of the resistant strains in comparison with the parent cells. Rubomycin and emoxyl were established not to affect practically the pool of phosphorus-containing metabolites in the cells of the resistant strains, but caused considerable increase of PME level in the cells of the parent strain.
