RESUMO
Apoptotic cell death of murine leukemia cells induced by E. coli L-asparaginase was studied. Deprivation of L-asparagine from the culture of L5178Y cells by L-asparaginase caused the fragmentation of chromosomal DNA of the leukemia cells within 24 h. Prior to the degradation of DNA, cell cycles of L5178Y cells were found to be arrested in G1 phase, and evidence of the DNA strand breaks was initially observed in G1 phase cells as early as 8 h after the asparaginase treatment. Therefore, apoptosis of leukemia cells induced by L-asparaginase is an event that is associated with the cell cycle arrest in G1 phase.
Assuntos
Antineoplásicos/farmacologia , Apoptose , Asparaginase/farmacologia , Ciclo Celular/efeitos dos fármacos , Dano ao DNA/genética , DNA de Neoplasias/efeitos dos fármacos , Leucemia L5178/genética , Animais , Apoptose/genética , Contagem de Células/efeitos dos fármacos , Ciclo Celular/genética , DNA de Neoplasias/genética , Citometria de Fluxo , Fase G1/efeitos dos fármacos , Fase G2/efeitos dos fármacos , Leucemia L5178/patologia , Camundongos , Células Tumorais Cultivadas/efeitos dos fármacosAssuntos
Apoptose/fisiologia , Leucemia L1210/patologia , Leucemia L5178/patologia , Valina/fisiologia , Animais , Apoptose/efeitos dos fármacos , Caspase 3 , Caspases/metabolismo , Meios de Cultura , Fragmentação do DNA , Isoleucina/efeitos dos fármacos , Isoleucina/fisiologia , Cinética , Leucemia L1210/enzimologia , Leucemia L5178/enzimologia , Camundongos , Células Tumorais Cultivadas , Valina/farmacologiaRESUMO
The jack bean lectin, concanavalin A (Con A), was modified with 2,4-bis[O-methoxypoly(ethylene glycol)]-6-chloro-s-triazine, activated PEG2, to form PEG-Con A. The immunoreactivity of PEG-Con A towards anti-Con A antibodies was reduced by increasing the degree of modification of amino groups in the Con A molecule. PEG-Con A had a complete reduction of the immunogenicity in mice and prolonged the clearance-time in blood. Although the mitogenic activity of Con A towards murine spleen cells was reduced by the conjugation with activated PEG2, the administration of PEG-Con A to mice enhanced the anti-tumor cytotoxicity of peripheral lymphocytes against melanoma B16 cells.