Protective effects of Stem Cell Factor in inhibiting X-rays induced apoptosis in HL60 cells

Background and Âpoptosis or programmed cell death is a process of cell suicide. Ïonizing radiation is one of the stimuli for apoptosis, acting through DNÂ damage. Ïn the present study, effects of X-rays induced apoptosis in HL60 cells, as well as the protective effects of Stem Çell Factor (SÇF) in inhibiting X-ray induced apoptosis have been evaluated. HL60 cells were exposed to 5 Gy of x-ray and the effect of time on the percentage of apoptotic cells was studied. Ône group of cells were incubated in medium containing SÇF at 37 o Ç for 1 h before X-ray exposure. Ôther groups of cells were incubated in media containing SÇF, MÂPK, PÏ3K and PKÇ inhibitors as the cellular pathway proteins, and the X-ray induced apoptosis was studied. The X-ray induced apoptosis show a graduall increase from 12h to 60h after X-ray. The SÇF attenuated the percentage of apoptotic cells when cells were treated with SÇF 1 h before X-ray. X-rays induced apoptosis partially attenuated by a combination treatment of SÇF and PKÇ and PÏ3K inhibitors, but it was not inhibited by the SÇF and ËRK inhibitors. Çonclusion: SÇF protected cells against X-rays through activation of MÂPK pathway.