Potent half-sandwich Ru(Ⅱ) N^N (aryl-BIAN) complexes: Lysosome-mediated apoptosis, in vitro and in vivo anticancer activities

Herein a new series of organometallic half-sandwich Ru(Ⅱ) complexes bearing aryl-BIAN chelating ligands with various electron-withdrawing and electron-donating substituents have been developed as theranostic agents. All the complexes display much higher anti-proliferative potency than the clinical chemotherapeutic drug cisplatin towards seven cancer cell lines. The anti-proliferative efficacy of these complexes is correlated to their electron-withdrawing ability. Interestingly, complex Ru1 also potently suppresses cancer cell migration in vitro and effectively inhibit tumor growth in vivo in a CT26 colon cancer mouse xenograft model. Mechanisms of action studies display that Ru1 can favorably accumulate in lysosome and exerts anti-cancer potency by inducing a series of events related to lysosomal dysfunction in CT26 cells. Interestingly, inhibition of lysosomal enzymes leads to suppression of cytotoxicity and apoptosis induced by Ru1. Our results elucidate that complex Ru1 can elicit cytotoxicity through lysosome-mediated apoptosis in vitro and suppress tumor growth in vivo.