Gallium (III) Complexes in Cancer Chemotherapy

Gallium, the group 13 metal, has been found to be potentially useful in fighting against cancers since last century. The trivalent Ga(III) shares most chemical properties except redox activity with Fe(III), so that it acts as a competitive inhibitor of Fe(III) in vitro and in vivo, which contributes to its antineoplastic activity. As an Fe(III) mimic, Ga(III) can be uptaken into cells through transferrin and be stored in ferritin. Furthermore, it disrupts Fe-dependent process, such as inhibiting the activity of ribonucleotide reductase and Fe-containing proteins in respiratory chain. To solve the problems of complex Ga(III) speciation in circulatory system, a large amount of ligands were applied to form Ga(III) complexes, supplying multiple functions. In this review, we summarized the anticancer mechanisms of Ga(III) and introduced numerous Ga(III) complexes with great antineoplastic potential.