The dynamic development of
metal-containing anticancer drugs has started since the discovery of
cis-diamminedichloroplatinum(II). For many years it was believed that trans
platinum(II) compounds were non-active as antitumour agents because trans-diamminedichloroplatinum is biologically inactive although it binds to
DNA and also forms monoadducts and cross-links. In the present work the ability of a novel
platinum(II) compound trans-[PtCl(2)(4-pmOpe)(2)] to induce DNA damage in human
non-small cell lung cancer cells A549 was examined using the alkaline comet assay. The obtained results revealed that the novel trans
platinum(II) complex induced
DNA strand breaks, which were effectively repaired during 2h of post-incubation, and cross-links which remained unrepaired under these test conditions. Apart from that, the modified comet assay with incubation with
proteinase K was used to verify the ability of trans-[PtCl(2)(4-pmOpe)(2)] and cis-DDP to form
DNA-
protein cross-links. It has been proved that only trans-[PtCl(2)(4-pmOpe)(2)] complex exhibits the ability to induce
DNA-
protein cross-links. The results suggest a different mechanism of action of this compound in comparison to cis-DDP. It seems that trans geometry and the presence of two diethyl (pyridin-4-ylmethyl)phosphates as non-leaving
ligands can determine dissimilar properties of the adducts formed on
DNA and the different mechanism of action of trans-[PtCl(2)(4-pmOpe)(2)] and in consequence the efficacy in killing
cancer cells.