DNA Oxidative Damage during Differentiation of HL-60 Human Promyelocytic Leukemia Cells
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- 作者：Valeria Covacci ; Angela Torsello ; Paola Palozza ; Alessandro Sgambato ; Giampiero Romano ; Alma Boninsegna ; Achille Cittadini ; and Federica I. Wolf
- 刊名：Chemical Research in Toxicology
- 出版年：2001
- 出版时间：November 2001
- 年：2001
- 卷：14
- 期：11
- 页码：1492 - 1497
- 全文大小：70K
- 年卷期：v.14,no.11(November 2001)
- ISSN：1520-5010
文摘
DNA oxidative damage was measured in human promyelocytic leukemia HL-60 cells, in thesame cells committed to granulocytic differentiation with dimethyl sulfoxide (DMSO) or all-trans-retinoic acid (RA) and in mature human peripheral granulocytes (HPG). DNA damagewas evaluated as single strand breaks and 8-OHdG adducts, measured by single cellelectrophoresis or by monoclonal antibodies, respectively. The basal levels of either marker ofDNA damage were higher in undifferentiated HL-60 cells than in HPG and DMSO- or RA-differentiated cells. Treatment with H2O2 increased 8-OHdG formation in all cells, but thelevels of DNA damage remained higher in undifferentiated cells as compared to thedifferentiated ones. Three lines of evidence suggested that the higher levels of DNA damageobserved in undifferentiated cells were at least in part attributable to a reduced detoxificationof reactive oxygen species (ROS). First, undifferentiated cells were shown to accumulate higherlevels of dichlorodihydrofluorescein-detectable ROS than HPG and DMSO- or RA-differentiatedcells. Second, undifferentiated HL-60 cells were characterized by reduced levels of GSH andlower GSH/GSSG ratios as compared to the differentiated cells. Third, pretreatment ofundifferentiated HL-60 cells with antioxidants such as 
-tocopherol or 
-carotene suppressedthe elevation of ROS and the formation of 8-OHdG induced by H2O2. Further evidence for theimportance of the oxidant/antioxidant balance was obtained by modulating the iron-catalyzeddecomposition of H2O2 to hydroxyl radicals in undifferentiated HL-60 cells. In fact, pretreatmentwith FeSO4 increased the formation of 8-OHdG induced by H2O2, whereas pretreatment withthe iron chelator deferoxamine produced the opposite effect. These results illustrate correlationsbetween the oxidant/antioxidant balance and DNA damage and suggest that the capability ofa cell population to withstand oxidative stress and DNA damage may depend on its degree ofdifferentiation.
-tocopherol or -carotene suppressedthe elevation of ROS and the formation of 8-OHdG induced by H2O2. Further evidence for theimportance of the oxidant/antioxidant balance was obtained by modulating the iron-catalyzeddecomposition of H2O2 to hydroxyl radicals in undifferentiated HL-60 cells. In fact, pretreatmentwith FeSO4 increased the formation of 8-OHdG induced by H2O2, whereas pretreatment withthe iron chelator deferoxamine produced the opposite effect. These results illustrate correlationsbetween the oxidant/antioxidant balance and DNA damage and suggest that the capability ofa cell population to withstand oxidative stress and DNA damage may depend on its degree ofdifferentiation.