Simultaneous mass spectrometry analysis of cisplatin with oligonucleotide-peptide mixtures: implications for the mechanism of action

Daniel Ortiz,Paul J. Dyson,Curtis A. Davey,Luc Patiny,Farangis Mansouri,Fakhrossadat Mohammadi,Laure Menin

doi:10.1007/s00775-022-01924-9

Abstract

Although genomic DNA is the primary target of anticancer platinum-based drugs, interactions with proteins also play a significant role in their overall activity. In this study, competitive binding of cisplatin with an oligonucleotide and two peptides corresponding to segments of H2A and H2B histone proteins was investigated by mass spectrometry. Following the determination of the cisplatin binding sites on the oligonucleotide and peptides by tandem mass spectrometry, competitive binding was studied and transfer of platinum fragments from the platinated peptides to the oligonucleotide explored. In conjunction with previous studies on the nucleosome, the results suggest that all four of the abundant histone proteins serve as a platinum drug reservoir in the cell nucleus, providing an adduct pool that can be ultimately transferred to the DNA.Graphical abstract

Highlights

Metal complexes exert a wide range of therapeutic effects [1, 2] and are extensively used in the diagnosis and treatment of diseases [3]
Platinated adducts corresponding to [stranded 13-mer oligonucleotide 5'-GTATTGGCACGTA-3' (S1) + Pt(NH3)28H]6− and [S1c + Pt(NH3)2-8H]6− were observed at m/z 701.4438 and 689.6103, respectively. These adducts were fragmented by collision-induced dissociation (CID) and, as expected, the main fragments resulting from cleavage of the oligonucleotide were a/w and a-B internal fragments
Subsequent competition studies between the oligonucleotide and the peptides confirmed that cisplatin reacts preferentially with the oligonucleotide

Summary

Introduction

Metal complexes exert a wide range of therapeutic effects [1, 2] and are extensively used in the diagnosis and treatment of diseases [3]. Among these metal complexes, cis-diamminedichloroplatinum(II), i.e. cisplatin, is the most commonly used drug in cancer chemotherapy [4]. In addition to DNA binding, cisplatin reacts with many proteins [7,8,9,10], with certain cisplatinprotein interactions leading to drug resistance [11]. Recent reports have revealed that other proteins, such as cytokeratin, elongation factor and histones, bind to DNA after cisplatin treatment [14, 15], affecting nuclear metabolism and chromatin organization [16]

Methods

Results

Conclusion