Genoscience Pharma, Marseille, France.
Aix-Marseille Univ, MEPHI, APHM, IRD, IHU Méditerranée Infection, Marseille, France.
Autophagy. 2022 Mar;18(3):678-694. doi: 10.1080/15548627.2021.1988357. Epub 2021 Nov 5.
Hepatocellular carcinoma is the most frequent primary liver cancer. Macroautophagy/autophagy inhibitors have been extensively studied in cancer but, to date, none has reached efficacy in clinical trials. In this study, we demonstrated that GNS561, a new autophagy inhibitor, whose anticancer activity was previously linked to lysosomal cell death, displayed high liver tropism and potent antitumor activity against a panel of human cancer cell lines and in two hepatocellular carcinoma in vivo models. We showed that due to its lysosomotropic properties, GNS561 could reach and specifically inhibited its enzyme target, PPT1 (palmitoyl-protein thioesterase 1), resulting in lysosomal unbound Zn accumulation, impairment of cathepsin activity, blockage of autophagic flux, altered location of MTOR (mechanistic target of rapamycin kinase), lysosomal membrane permeabilization, caspase activation and cell death. Accordingly, GNS561, for which a global phase 1b clinical trial in liver cancers was just successfully achieved, represents a promising new drug candidate and a hopeful therapeutic strategy in cancer treatment.: ANXA5:annexin A5; ATCC: American type culture collection; BafA1: bafilomycin A; BSA: bovine serum albumin; CASP3: caspase 3; CASP7: caspase 7; CASP8: caspase 8; CCND1: cyclin D1; CTSB: cathepsin B; CTSD: cathepsin D; CTSL: cathepsin L; CQ: chloroquine; iCCA: intrahepatic cholangiocarcinoma; DEN: diethylnitrosamine; DMEM: Dulbelcco's modified Eagle medium; FBS: fetal bovine serum; FITC: fluorescein isothiocyanate; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; HCC: hepatocellular carcinoma; HCQ: hydroxychloroquine; HDSF: hexadecylsulfonylfluoride; IC: mean half-maximal inhibitory concentration; LAMP: lysosomal associated membrane protein; LC3-II: phosphatidylethanolamine-conjugated form of MAP1LC3; LMP: lysosomal membrane permeabilization; MALDI: matrix assisted laser desorption ionization; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MKI67: marker of proliferation Ki-67; MTOR: mechanistic target of rapamycin kinase; MRI: magnetic resonance imaging; NHCl: ammonium chloride; NtBuHA: N-tert-butylhydroxylamine; PARP: poly(ADP-ribose) polymerase; PBS: phosphate-buffered saline; PPT1: palmitoyl-protein thioesterase 1; SD: standard deviation; SEM: standard error mean; vs, versus; Zn: zinc ion; Z-Phe: Z-Phe-Tyt(tBu)-diazomethylketone; Z-VAD-FMK: carbobenzoxy-valyl-alanyl-aspartyl-[O-methyl]- fluoromethylketone.
肝细胞癌是最常见的原发性肝癌。自噬抑制剂在癌症研究中已经得到了广泛的研究，但迄今为止，没有一种在临床试验中达到疗效。在这项研究中，我们证明了 GNS561，一种新的自噬抑制剂，其先前与溶酶体细胞死亡相关的抗癌活性，表现出对一组人类癌细胞系和两种肝癌体内模型的高肝趋向性和强大的抗肿瘤活性。我们表明，由于其溶酶体靶向特性，GNS561 可以到达并特异性抑制其酶靶标 PPT1（棕榈酰蛋白硫酯酶 1），导致溶酶体未结合的 Zn 积累、组织蛋白酶活性受损、自噬流阻断、改变 MTOR（雷帕霉素机制靶标激酶）的位置、溶酶体膜通透性、半胱天冬酶激活和细胞死亡。因此，GNS561 最近在肝癌的全球 1b 期临床试验中取得了成功，它代表了一种很有前途的新药候选物和癌症治疗的有希望的治疗策略。
