Enhancement of radiation-induced apoptosis by preirradiation with low-dose X-rays in human leukemia MOLT-4 cells.
The effects of low-dose preirradiation on the process of radiation-induced cell death were investigated in human leukemic MOLT-4 cells. By 0.2 Gy of X-rays given 12 h prior to a challenge dose of 5 Gy, the process of apoptosis was accelerated. The acceleration was associated with a certain increase in caspase 3 activity, a disruption of the mitochondrial transmembrane potential, and an accumulation of p53 proteins. This finding is in contrast to the radiation adaptive responses in which a small dose of preirradiation would induce certain radiation resistance and decrease the cell death after irradiation with higher doses.
Low Dose Radiation Research Center, Central Research Institute of Electric Power Industry, Tokyo, Japan.
Zhiyun
Z
Chen
Kazuo
K
Sakai
D000222:Adaptation, Physiological / Q000528:radiation effects; D017209:Apoptosis / Q000528:radiation effects*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism*; D045744:Cell Line, Tumor / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D004789:Enzyme Activation / Q000528:radiation effects; D006801:Humans; D007938:Leukemia / Q000378:metabolism* / Q000473:pathology*; D011829:Radiation Dosage; D011836:Radiation Tolerance / Q000528:radiation effects*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D014965:X-Rays
D016159:Tumor Suppressor Protein p53; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases