Novel phenylenediamine bridged mixed ligands dimetallic square planner Pt(II) complex inhibits MMPs expression via p53 and caspase-dependent signaling and suppress cancer metastasis and invasion.

Novel phenylenediamine bridged mixed ligands dimetallic square planner Pt(II) complex (L-Pt-Py) was synthesized from simple commercially available precursors in good yield and characterized by (1)H, (13)C, 2D NOESY NMR and high resolution mass spectrometry (HR-ESI-MS). The stability of L-Pt-Py was checked by (1)H NMR in mixed DMSO-d6/D2O solvents. L-Pt-Py showed considerable in vitro cytotoxicity in lung (A549), breast (MCF-7) and liver (HepG2) cancer cell lines and strong in vivo growth inhibition in Escherichia coli (E. coli). These results were compared to the well-known market available platinum anticancer drug cisplatin. L-Pt-Py has strong ability to suppress the growth of multiple cancer cells. Mechanistically, it enhanced p53 protein expression and regulated p53-dependent genes expression such as p21, PUMA, MYC and hTERT. The TUNEL assay showed that L-Pt-Py induced cell death in cancer cells. Inhibition of caspase signaling with caspase inhibitor Z-VAD-FMK suggested that cell death induced by this complex was caspase-dependent. Importantly, L-Pt-Py has the ability to suppress the invasion and migration of human lung and luminal-like breast cancer cells. Similarly L-Pt-Py suppressed the expression of several matrix metalloproteinases (MMPs) such as MMP-1, MMP-2, MMP-3, MMP-7 and MMP-9 to inhibit lung and breast cancer cell metastasis. L-Pt-Py showed stronger inhibitory effects on bacterial growth and also resulted in filamentous morphology of bacterial cells. The gel electrophoresis study of DNA migration revealed the strong interaction of L-Pt-Py with DNA. Taken altogether, L-Pt-Py was highly stable and the in vitro and in vivo biological study results corroborated this complex to be effective anticancer agent.