An LC/MS based method to quantify DNA adduct in tumor and organ tissues

• Published in: Analytical biochemistry Vol. 568; pp. 1 - 6
• Main Authors: Li, Chao, Dong, Linlin, Kamali, Afrand, Sugimoto, Hiroshi, Abdul-Hadi, Kojo, Chen, Susan, Abu-Yousif, Adnan, Qian, Mark G.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.03.2019
• Subjects: Animals; Benzodiazepines - analysis; Chromatography, Liquid; DNA Adducts - analysis; Humans; Immunoconjugates - analysis; Liver - chemistry; Mass Spectrometry; Mice; Mice, SCID; Molecular Structure; Neoplasms, Experimental - diagnosis; Spleen - chemistry
• ISSN: 0003-2697; 1096-0309
• DOI: 10.1016/j.ab.2018.12.014

Highly potent DNA damaging agents have become a key class of toxins for antibody-drug conjugate (ADC) based targeted therapy. However, until recently, no quantitative bioanalytical method was available to measure the toxin in the form of DNA adducts. In this work, a novel microwave assisted organic solvent extraction and LC-MS/MS based bioanalytical method was developed to extract and quantify DNA-bound toxin IGN-P1 in tissue samples. Using ADC-1 as the model ADC, the method was orthogonally checked with a radioactive method for the recovery of free toxins from DNA adducts in biological matrices. It was found that the bioanalytical method can achieve a high recovery of the IGN-P1 toxin from DNA adducts. In further assessment, tumor and organ tissue samples collected at multiple time points from in vivo studies after dosing with two other ADCs, ADC-2 and ADC-3, were measured by the method. Given the generic nature of the established bioanalytical method without the need of radiolabels, the methodology could be broadly utilized to quantitatively assess the relationship between DNA adduct levels and pharmacological/toxicological effects. •A novel LC-MS/MS based bioanalytical method was developed to quantify DNA-bound toxin IGN-P1 in tissue samples.•A high recovery of the toxin from DNA adducts can be achieved from tissue samples as shown in in vivo studies with ADCs.•The method could be utilized to assess the relationship between DNA adduct levels and pharmacological/toxicological effects.