Au(III)-proline derivatives exhibiting selective antiproliferative activity against HepG2/SB3 apoptosis-resistant cancer cells

This paper deals with the combination of a proline-based moiety with biologically active gold centers in the oxidation state +1 and +3. In particular, six Au(I)/(III)-proline dithiocarbamato (DTC) complexes, with general formulae [AuI2(DTC)2] and [AuIIIX2(DTC)] (X=Cl, Br) are here reported. After the synthesis of the ligand and the complexes, all derivatives were characterized via several techniques, and tested for their stability in DMSO/water media. This study was focused on the demonstration of a peculiar behavior of Au(III)-DTC species in solution. Finally, the complexes were screened for their antiproliferative activity against 2 human cancer cell lines, namely HepG2 and HepG2/SB3, taken as a model of hepatocellular carcinoma. The latter, chosen for its aggressiveness due to the upregulation of the anti-apoptotic protein SerpinB3, was selectively inhibited in terms of growth by some Au(III)-DTC complexes.