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

Contrarily to what 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 profile, 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) analysis. Data reveal that cis- PtI2(NH3)2 shows an overall reactivity towards the investigated oligonucleotides significantly higher than cisplatin.