A Golgi-Targeted Platinum Complex Plays a Dual Role in Autophagy Regulation for Highly Efficient Cancer Therapy.

Abstract

Regulating autophagy to control the homeostatic recycling process of cancer cells is a promising anticancer strategy. Golgi apparatus is a substrate of autophagy but the Golgi-autophagy (Golgiphagy) mediated antitumor pathway is rarely reported. Herein, we have developed a novel Golgi-targeted platinum (II) complex Pt3, which is ca. 20 times more cytotoxic to lung carcinoma than cisplatin and can completely eliminate tumors after intratumoral administration in vivo. Its nano-encapsulated system for tail vein administration also features a good anti-tumor effect. Mechanism studies indicate that Pt3 induces substantial Golgi stress, indicated by the fragmentation of Golgi structure, down-regulation of Golgi proteins (GM130, GRASP65/55), loss of Golgi-dependent transport and glycosylation. This triggers Golgiphagy but blocks the subsequent fusion of autophagosomes with lysosomes, that is a dual role in autophagy regulation, resulting in loss of proteostasis and apoptotic cell death. As far as we know, Pt3 is the first Golgi-targeted Pt complex that can trigger Golgi stress-mediated dual-regulation of autophagic flux and autophagy-apoptosis crosstalk for highly efficient cancer therapy.