Exposure to fractionated dose of 60 Gy affects molecular response of HL-60 cells to irradiation.
Gen Physiol Biophys
; 29(3): 275-81, 2010 Sep.
Article
en En
| MEDLINE
| ID: mdl-20817951
ABSTRACT
In this work we evaluated changes in molecular response of human promyelocyte leukemia cells HL-60 and HL-60-IR cells (HL-60 irradiated by 10 cycles of radiation with total dose of 60 Gy, given over a period of 3 months) to irradiation by the dose of 2 and 8 Gy. Analysis of CD11b and apoptosis by flow-cytometry revealed that on 3rd day after irradiation by 8 Gy the HL-60-IR are more resistant to radiation-induced apoptosis and more differentiated (increase in CD11b in non-apoptotic cells) than regular HL-60. We found that both types of cells have high basal level of phosphorylated extracellular signal-regulated kinases Erk1/2 . Irradiation induces decrease in Erk1/2 phosphorylation after 4 and 8 h in both cell types. However, in HL-60-IR cells Erk1/2 phosphorylation is restored faster than in HL-60. Also it was found that in contrary to HL-60 cells, the HL-60-IR cells react to 2 Gy irradiation by p53 independent increase in p21(WAF1/Cip1), and not by activation of checkpoint kinase Chk-2. Therefore we concluded that relatively high dose of radiation (6 Gy) does not lead after 10 repetitive irradiations to eradication of HL-60 cells, but instead increases their radioresistance, increases the ability to differentiate, alters MAPK response, increases amount of p21(WAF1/Cip1), and decreases induction of apoptosis by ionizing radiation. p21(WAF1/Cip1) might prevent apoptosis induction and trigger permanent cell-cycle arrest, which can also contribute to regression of this leukaemia after therapy.
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Colección:
01-internacional
Base de datos:
MEDLINE
Contexto en salud:
6_ODS3_enfermedades_notrasmisibles
Problema de salud:
6_leukemia
Asunto principal:
Tolerancia a Radiación
/
Leucemia Promielocítica Aguda
/
Sistema de Señalización de MAP Quinasas
Límite:
Humans
Idioma:
En
Revista:
Gen Physiol Biophys
Año:
2010
Tipo del documento:
Article
País de afiliación:
República Checa