A first-in-class and a fished out anticancer platinum compound: cis-[PtCl2(NH3)(2)] and cis-[PtI2(NH3)(2)] compared for their reactivity towards DNA model systems

Contrary to what was believed for many years, cis-PtI2(NH3)(2), the diiodido analogue of cisplatin, displays high in vitro antiproliferative activity toward a set of tumour cell lines, overcoming resistance to cisplatin in a platinum-resistant cancer cell line. In the context of a general reappraisal of iodinated Pt(II) derivatives, aiming at a more systematic evaluation of their chemical and biological profiles, here we report on the reactivity of cis-PtI2(NH3)(2) with selected DNA model systems, in single, double strand or G-quadruplex form, using cisplatin as a control. A combined approach has been exploited in this study, including circular dichroism (CD), UV-visible spectroscopy and electrospray mass spectrometry (ESI-MS) analyses. The data reveal that cis-PtI2(NH3)(2) shows an overall reactivity towards the investigated oligonucleotides significantly higher than cisplatin.