Structural variations in the trans-carboxylate/chlorido axis that impact the mode of action of Pt(ii) complexes

Abstract

The design of trans-platinum(II) complexes marked a significant turning point in the development of unconventional anticancer metallodrugs. Compared to cisplatin, these complexes induce distinctly different cellular responses and are often active against cisplatin-resistant cell lines. In this study, we synthesized and fully characterized two new Pt(II) complexes, introducing one acetate (⁻OCOCH₃) ligand (X) into the trans-PtXX′ axis, where X′ is either acetate or chlorido. We evaluated their cytotoxicity across a panel of malignant (Capan-1, B16, MCF7, HCT-116, CT26 and P31) and non-malignant (HaCaT, HUVEC, BEC, and MCF10A) cell lines, finding that the complex with only one acetate trans to a chlorido group is more active and selective than the complex with two acetates (X = X′). Furthermore, the two complexes differ from cisplatin in their cellular uptake route as well as mode of action by inducing cancer cell death via non-DNA-associated mechanisms.