Synthesis, RNA-sequence and evaluation of anticancer efficacy of ruthenium(II) polypyridyl complexes toward HepG2 cells

Abstract

In this article, four new Ru(II) complexes [Ru(dmbpy)2(TFBIP)](PF6)2 (dmbpy = 4,4′-dimethyl-2,2′-bipyridine, TFPIP = 2-(4′-trifluoromethyl)-[1,1′-biphenyl]-4-yl)-1H-imidazo[4,5-f][1,10]phenanthroline) (Ru1), [Ru(bpy)2(TFBIP)](PF6)2 (bpy = 2,2′-bipyridine) (Ru2), [Ru(phen)2(TFBIP)](PF6)2 (phen = 1,10-phenanthroline) (Ru3) and [Ru(dmp)2(TFBIP)](PF6)2 (dmp = 2,9-dimethyl-1,10-phenanthroline) (Ru4) were synthesized and characterized by elemental analysis, HRMS, IR, 1H NMR, 13C NMR and 19F NMR. The in vitro anticancer effect of the complexes on HepG2, A549, B16, HeLa, BEL-7402 and non-cancer LO2 cells was screened using 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) method. The results illustrate that the complexes display moderate anticancer activity. Apoptotic assay with Annexin V/PI double staining method indicated that complexes induce apoptosis in HepG2 cells. Also, the complexes interfere with the mitochondrial functions, accompanied by the production of intracellular ROS as well as a reduction of mitochondrial membrane potential. The results obtained from the western blot demonstrated that the complexes upregulate pro-apoptotic Bax and downregulate anti-apoptotic Bcl-2, which further activates caspase 3 and promotes the cleavage of PARP. RNA-sequence showed that the complexes upregulate the expression of 40 genes and downregulate 66 genes. Antitumour in vivo demonstrated that Ru1 inhibits the tumor growth with a high inhibitory rate of 51.19%. Taken together, these results revealed that complexes Ru1, Ru2, Ru3 and Ru4 induce cell death in HepG2 cells via autophagy and a ROS-mediated mitochondrial apoptotic pathway.