Separation and characterization of oxaliplatin dinucleotides from DNA using HPLC-ESI ion trap mass spectrometry.
Oxaliplatin is a third-generation platinum complex, and has a broad spectrum of antitumor activity. Such platinum complexes with the DACH carrier ligand have recently received increasing attention since they show efficacy against cisplatin-resistant cell lines. As the foremost indication of antitumor activity of platinum drugs is the formation of adducts with genomic DNA, calf thymus DNA-oxaliplatin adducts were the major target in this study. Calf thymus DNA was incubated with oxaliplatin, resulting in the formation of a large number of platinum-DNA adducts. Treated DNA was digested into the dinucleotides with a combination of enzymes, namely, benzonase, alkaline phosphatase, and nuclease S1. Using a high-performance liquid chromatography, we carried out the separation of individual platinum-DNA adducts which were concurrently identified using electrospray ionization ion trap mass spectrometry (MS). Both 1,2-intrastrand and 1,2-interstrand cross-linked adducts were found; however, those of the intrastrand nature have a considerably higher abundance than those of the interstrand cross-links. Among them, d(GpG)-oxaliplatin was the most abundant bifuctional adduct. To a lesser extent, a few monofunctional adducts were detected as well. MS(n) experiments served to ascertain the detailed structures of oxaliplatin adducts of dinucleoside monophosphates and of dinucleotides.
Mowaka
Shereen
S
Department of Chemistry, Humboldt Universitaet zu Berlin, Brook-Taylor-Str. 2, 12489, Berlin, Germany.
Linscheid
Michael
M
D000469:Alkaline Phosphatase / Q000378:metabolism; D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004247:DNA / Q000378:metabolism*; D018736:DNA Adducts / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D015226:Dinucleoside Phosphates / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D004706:Endodeoxyribonucleases / Q000378:metabolism; D004722:Endoribonucleases / Q000378:metabolism; D009944:Organoplatinum Compounds / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D000077150:Oxaliplatin; D015719:Single-Strand Specific DNA and RNA Endonucleases / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013997:Time Factors
D000970:Antineoplastic Agents; D018736:DNA Adducts; D015226:Dinucleoside Phosphates; D009944:Organoplatinum Compounds; D000077150:Oxaliplatin; D004247:DNA; C427203:calf thymus DNA; D004706:Endodeoxyribonucleases; D004722:Endoribonucleases; D000469:Alkaline Phosphatase; D015719:Single-Strand Specific DNA and RNA Endonucleases; C021835:Serratia marcescens nuclease