An investigation of the sequence-specific interaction of cis-diamminedichloroplatinum(II) and four analogs, including two acridine-tethered complexes with DNA inside human cells

Abstract

The sequence specificity of DNA damage caused by cis-diamminedichloroplatinum(II) (cisplatin) and four analogues in human (HeLa) cells was studied using Taq DNA polymerase and a linear amplification system. The primer extension is inhibited by the drug-DNA adducts, and hence the sites of these lesions can be analyzed on DNA sequencing gels. The repetitive alphoid DNA was used as the target DNA in human cells. A comparison was made between adduct formation in human cells and in purified DNA. The sequence-specific position and relative intensity of damage was similar in both systems for cisplatin, dichloro(ethylenediammine)platinum(II) (PtenCl2), and N-[3-N-(ethylenediamino)propyl]acridine-4-carboxamidedichloropl atinum(II) (4AcC3PtenCl2). However, no DNA damage could be detected in cells for trans-diamminedichloroplatinum(II) (transPt) or N-[3-N-(ethylenediamino)propyl]acridine-2-carboxamide-dichloroplat inum(II) (2AcC3PtenCl2) despite the ability of these latter analogues to damage purified DNA. Cisplatin, PtenCl2, and 4AcC3PtenCl2, which significantly damaged DNA inside cells, also show antitumor activity in mouse models. However, transPt and 2AcC3PtenCl2, which did not detectably damage DNA inside cells, did not show such antitumor activity. This correlation between intracellular DNA damaging ability and in vivo antitumor activity indicates the potential use of the human cells/Taq DNA polymerase/linear amplification technique as a convenient method for screening new cisplatin analogues for useful chemotherapeutic activity.

Substituted 9-aminoacridine-4-carboxamides tethered to platinum(II)diamine complexes: Chemistry, cytotoxicity and DNA sequence selectivity

“…In these experiments damage at sites other than consecutive guanines were prominent as previously found for 1 (n = 2) [17,[24][25][26]. The sequence selectivity of 1 (n = 2), 5, 6 and 7 was different to that of cisplatin as the damage sites were shifted away from consecutive guanines.…”

“…The interaction of the compounds in intact human cells has also been investigated using the linear amplification assay [24,27,28].…”

Platinum‐based anticancer agents: Innovative design strategies and biological perspectives

“…For example, novel Pt complexes were created utilizing DNA intercalators such as anilinoacridine (21) and acridinecarboxamide (22) as the carrier ligands, with the anticipation that the compounds would localize in the vicinity of DNA and exert superior cytotoxic effects. [121][122][123] Although these complexes exhibited improved activity in cisplatinresistant cell lines compared to cisplatin, there was no improvement relative to the use of the carrier ligands alone.…”

DNA damage by anti-cancer agents resolved at the nucleotide level of a single copy gene: evidence for a novel binding site for cisplatin in cells

“…DNA damage at the nucleotide level within cells treated with anti-cancer drugs has been investigated but these limited studies looked at the highly reiterated a-DNA and, while providing some useful information, have limited physiological significance (14,15 …”