Rhodium (II) complex with 2-benzoylpyridine, a novel potential chemotherapeutic drug, induces cell cycle arrest and apoptosis in HepG2 cells

Rhodium (II) complex with 2-benzoylpyridine (Rh(L)(2)Cl-2) is a new, synthetic, active metal-complex, which is produced by the reaction of 2-benzoylpyridine (L) with rhodium chloride hydrate (RhCl3 center dot nH(2)O). The crystal structure was determined by X-ray diffraction which is mono-nuclear. In order to explore the biological properties of the novel complex, a series of studies were performed. The results showed that Rh(L)(2)Cl-2 had the anti-tumor activity in HepG(2) and other cell lines and has been shown to induce G1 cell cycle arrest and apoptosis in HepG(2) cells. The anti-cancer effect of Rh(L)(2)Cl-2 is regulated by increased expression of caspase-3 and PARP via the mitochondrial and the death receptor pathways. Bcl-2 family proteins might play an important role in the Rh(L)(2)Cl-2-induced changes in these two pathways. Further studies indicated that Rh(L)(2)Cl-2 increased the level of reactive oxygen species (ROS), but that Rh(L)(2)Cl-2-induced apoptosis was ROS-independent. In conclusion, Rh(L)(2)Cl-2 is a potential new anti-tumor drug, which induces HepG(2) cell death via the mitochondrial and death receptor pathways and has no obvious toxicity to normal liver cell.