Ruthenium compounds in cancer therapy

Abstract

The examination of the biological roles of ruthenium complexes as well as the possibility of producing ruthenium-based drugs, active in the treatment of human malignancies, is believed to have begun with the discovery of the antineoplastic activity of cis-dichlorodiammine platinum(II) (hereafter called cisplatin). The fate of ruthenium compounds is common to that of many other transition metals. Based on the elementary observation that ruthenium belongs to the Group VIII transition metals (the so-called platinum group), ruthenium compounds have been studied in comparison to cisplatin in order to ameliorate cisplatin toxicity and potency. In other words, like palladium, rhodium, iridium, osmium and other transition metals, ruthenium was studied in order to obtain compounds which are more potent than cisplatin and under the same conditions in which cisplatin is active. Therefore, from most investigations it is expected that ruthenium compounds will reduce tumour growth by a mechanism of interaction with cell DNA, similar to that shown by cisplatin. Nevertheless, an accurate examination of the literature on ruthenium compounds reveals that these metal-based antitumour drugs show a number of differences from cisplatin, particularly when tumour sensitivity and the effects of tumour reduction on host survival time are concerned. It thus appears that ruthenium compounds can have a selected place in therapy, different from that of cisplatin, and can represent a tool for investigating antitumour chemotherapy and for opening a new direction in the development of a new generation of anticancer agents.