Objective To explore the role and mechanism of desferrioxamine(DFO)aggravating temozolomide(TMZ)-induced DNA damage in glioma cells.Methods U251 glioma cells were divided into control group,TMZ group(100 μmol/L),DFO group(500 μmol/L)and two-drug combined treatment group(100 μmol/L TMZ+500 μmol/L DFO).After 24 h of treatment,the formation of phosphorylated histone H2AX(γH2AX)focus was detected by immunofluorescence;intracellular total iron content and mitochondrial iron content were detected by phenanthrozine-colourimetric and chemiluminescent methods,respectively;mitochondrial membrane potential was detected by fluorescence,and intracellular ATP content and lactic acid content were determined by ATP kit and lactate acid kit,respectively;qRT-PCR analyzed the mRNA expression of molecules related to iron-sulfur cluster(ISC)synthesis,and Western blotting analyzed the expression of proteins related to DNA damage repair.Results DFO and TMZ caused DNA damage in glioma cells to different degrees(P＜0.05),and DFO could exacerbate temozolomide-induced DNA damage in glioma cells(P＜0.01).DFO combined with TMZ significantly reduced total and mitochondrial iron content of the cells(P＜0.05),lowered the mitochondrial membrane potential and ATP content(P＜0.01),and increased the production of lactic acid(P＜0.01).DFO impeded ISC synthesis,inhibited DNA damage repair,and aggravated TMZ-induced DNA damage(P＜0.05).Conclusion DFO causes mitochondrial dysfunction by affecting iron metabolism and reduced ISC synthesis,thereby inhibiting DNA damage repair and aggravating TMZ-induced DNA damage in glioma cells.
维普
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