Biologic activity of a dinuclear Pd(II)-spermine complex toward human breast cancer

A dinuclear palladium-based complex (Pd₂-Spm) was synthesized and compared with cisplatin (cDDP) on two different human breast cancer cell lines (MCF-7 and MDA-MB-231) as well as toward an untransformed cell line (BJ fibroblasts). The results obtained show that Pd₂-Spm is more effective against the estrogen receptors [ER(-)] cell line MDA-MB-231, while cDDP displayed better results for the ER(+) MCF-7 cell line. It was shown that, like cDDP, Pd₂-Spm triggers phosphorylation of H2AX, indicating that this compound damages DNA. Apart from DNA, Pd₂-Spm also targets the cytoskeleton having a greater impact on cell morphology than cDDP. Pd₂-Spm and cDDP have opposite antiproliferative activities in the presence of the PI3K inhibitor wortmannin. Furthermore, Pd₂-Spm at an optimized concentration displays a rapid antiproliferative effect as opposed to cDDP, which seems to have a slower kinetics. The results point to a distinct mechanism of action for each of these complexes, which may explain their synergistic action when coadministrated. A spermine dinuclear palladium(II) complex (Pd₂-Spm) was synthesized and tested towards two human breast cancer cell lines (MCF-7 and MDA-MB-231) as to its antiproliferative properties, and compared to the widely used drug cisplatin (cDDP). For optimized concentrations Pd₂-Spm induced a rapid growth-inhibiting effect, as opposed to cDDP which seems to have a slower kinetics. The results evidence a possible distinct mechanism of action for these two Pt(II) complexes, which may explain their synergistic activity when co-administered.