Synthesis, characterization, antiproliferative and anti-metastatic properties of two ruthenium-DMSO complexes containing 2,2'-biimidazole.

Two new ruthenium complexes, trans,cis,cis-[RuCl2(DMSO)2(H2biim)] (1) and mer-[RuCl3(DMSO)(H2biim)] (2) (DMSO=dimethyl sulfoxide and H2biim=2,2'-biimidazole), have been synthesized and fully characterized by single-crystal X-ray analysis. The less stable complex 2 is more cytotoxic against the four human cancer cell lines tested than 1. Further studies show that 1 and 2 exhibit cell growth inhibition by triggering G0/G1 cell cycle arrest and mitochondria-mediated apoptosis. Additionally, complex 2 exerts potent inhibitory effects on the adhesion and migration of human cancer cells comparable to that of NAMI-A ([ImH][trans-[RuCl4(Im)(DMSO-S)], Im=imidazole). Target validation studies show that cyclin-dependent kinases (CDKs), other than DNA, are more likely to be targets of 1 and 2.