Radiation-induced apoptosis and cell cycle progression in TP53-deficient human leukemia cell line HL-60.
Human promyelocytic leukemia (HL-60) cells were irradiated with 0.5-100 Gy of gamma radiation and studied for 48 h post irradiation to determine the mode of death and progression of cells through the phases of the cell cycle. HL-60 cells are much more sensitive to radiation-induced loss of clonogenicity (D0 = 2.2 Gy) than to induction of apoptosis at 6 h (D0 for nonapoptotic cells = 32.6 Gy). After doses 20-50 Gy, the onset of massive apoptosis occurred and nonapoptotic cells were in G1/G0 phase of the cell cycle. In contrast, 6 h after irradiation with doses 2.5-10 Gy maximum cells were in S-phase and 16-24 h after irradiation were arrested in G2-phase. Maximum apoptosis occurred 48 h after irradiation with doses 3.5-10 Gy, and cells that died by necrosis were found in 9-44%.
Vávrová
J
J
Institute of Radiobiology and Immunology, Purkyne Military Medical Academy, Hradec Králové, Czech Republic. vavrova@pmfhk.cz
Mareková
M
M
Vokurková
D
D
D017209:Apoptosis; D002453:Cell Cycle / Q000528:radiation effects; D018922:HL-60 Cells / Q000502:physiology / Q000528:radiation effects*; D006801:Humans; D009336:Necrosis; D011878:Radiotherapy; D013997:Time Factors