Rhee J G, Song C W, Kim T H, Levitt S H
Radiat Res. 1985 Mar;101(3):519-27.
The capacity of HL-60 cells, human acute promyelocytic leukemic cells established in culture, to repair sublethal radiation damage was estimated from the response of the cells to fractionated irradiation or to a single irradiation at different dose rates. The HL-60 cells grown as a suspension culture in RPMI 1640 medium supplemented with 10% calf serum and antibiotics showed a cloning efficiency of about 0.46 in an agar culture bed. After exposure of cells to a single dose of X rays at a dose rate of 78 rad/min, the survival curve was characterized by n = 2.5, Dq = 80 rad, and D0 = 83.2 rad. Split-dose studies demonstrated that the cells were able to repair a substantial portion of sublethal radiation damage in 2 hr. The response of the cells to irradiation at different dose rates decreased with a decrease in the dose rates, which could be attributed to repair of sublethal radiation damage. The radiation response of leukemic cells is only one of the many factors which affect the clinical outcome of total-body irradiation (TBI) followed by bone marrow transplantation. Nevertheless, the possibility that some of the malignant hemopoietic cells, if not all, may possess a substantial capacity to repair sublethal radiation damage should not be underestimated in planning total-body irradiation followed by bone marrow transplantation.
HL-60细胞是在培养中建立的人急性早幼粒细胞白血病细胞，其修复亚致死性辐射损伤的能力是根据细胞对分次照射或不同剂量率单次照射的反应来估计的。在补充有10%小牛血清和抗生素的RPMI 1640培养基中作为悬浮培养物生长的HL-60细胞，在琼脂培养床中的克隆效率约为0.46。细胞以78拉德/分钟的剂量率接受单次X射线照射后，存活曲线的特征为n = 2.5、Dq = 80拉德和D0 = 83.2拉德。分次剂量研究表明，细胞能够在2小时内修复大部分亚致死性辐射损伤。细胞对不同剂量率照射的反应随着剂量率的降低而降低，这可归因于亚致死性辐射损伤的修复。白血病细胞的辐射反应只是影响全身照射（TBI）后进行骨髓移植临床结果的众多因素之一。然而，在计划全身照射后进行骨髓移植时，不应低估一些恶性造血细胞（即使不是全部）可能具有相当大修复亚致死性辐射损伤能力的可能性。
