Potential Activity of Non-Platinum Metal-Based Organic Complexes Against Different Cancer Cell Types

The disadvantages of Cisplatin in anticancer treatment are connected to its poor selectivity, resistance developed of cancers to the drug, and its toxicity against normal organs. An important strategy in anticancer treatment is the synthesis and clinical investigation of non-platinum metal complexes with superior anticancer activity and improved selectivity compared to Cisplatin, combined with lower toxicity, fewer side effects and decreased resistance of cancer to the drug. In the current study, we aim to summarize the potential of important non-platinum metal-based organic compounds as therapeutic agents against different cancer cell types. The review covers the general principles of chemotherapy. A literature analysis shows that organic complexes of the metalloids arsenic (As), boron (B), antimony (Sb), and selenium (Se), and of metals, such as Ag, Au, Co, Cu, Fe, Mn, Mo, Ni, Zn, Ce, Ga, Gd, Ir, Os, Pd, Re, Rh, Ru, Ti, and V, have been investigated for potential applications in cancer therapy. This is due to their antiproliferative effects against different cancer types: lung [Cd(II), Co(II), Cu(II), Ni(II), Mn(II), Ru(II), Zn(II)]; breast [Ag(I), Cu(I), Cu(II), Ir(III), Ni(II), Mn(II),. Rh(III), Ru(II)]; gastric [Cu(II), Cu(II)-La(III)]; colon [Ag(I), Cu(II), Ir(III), Pd(II), Rh(III), Ru(II), vanadium(V)]; colorectal [Ag(I), Co(II), Cu(II), Zn(II)]; liver [Ag(I), Co(II), Cu(II), Gd(III), vanadium(V)]; pancreatic [vanadium(IV)]; bladder [Ag(I), Cu(II), Ru(II)]; cervical [Ag(I), Au(I), Cu(I), Cu(II), Fe(II), Ir(III), Rh(III), Ru(II)]; testicular [vanadium(IV)]; prostate [Cu(II), Pd(II), Zn(II)]; leukemia [Ag(I), Co(II), Cu(II), Pd(II), Zn(II)]; sarcoma [Co(II), Ni(II), Zn(II)]; mesothelioma [Cu(II)]; neuroblastoma [Cu(II)]; glioma [Cu(II)]; and melanoma [Au(I), Cu(II), Pd(II), Ru(II)]. The main goals for increasing anticancer metal-based complexes include increasing anticancer activity and selectivity, reducing toxicity, and avoiding cancer cell resistance. Compared to Cisplatin, organocomplexes of copper, ferrocene, and ruthenium are more active. Ruthenium and copper complexes, in particular, are also more selective. Notably, ruthenium and ferrocene derivatives are less toxic than Cisplatin. Lastly, cancers appear to exhibit less resistance against copper, gold, ruthenium, palladium, and ferrocene complexes.