Ponicidin是一种在临床试验中具有证明的抗肿瘤活性的二萜。然而,针对肝细胞癌(HCC)的具体功能和作用机制尚不清楚。在这项研究中,研究发现,ponicidin显著抑制肝癌细胞的增殖和迁移。表明,ponicidin靶向Keap1并促进Keap1-PGAM5复合物的形成,导致PGAM5的泛素化,使用生物素标记的ponicidin进行靶向捕捞和HuProtTM人类蛋白质组微阵列V4.0。发现Ponicidin通过PGAM5激活半胱氨酸依赖性线粒体途径,导致线粒体损伤和ROS产生,从而促进HepG2细胞线粒体凋亡。获得了PGAM5IE12聚体肽和Keap1Kelch结构域的第一个体外共晶结构。使用分子动力学模拟来确认ponicidin与Keap1-PGAM5复合物的结合。基于深度的动态仿真,发现ponicidin可以诱导Keap1-PGAM5相互作用口袋的收紧,从而稳定蛋白质复合物的形成。最后,在BALB/c裸鼠异种移植瘤模型中观察到ponicidin有效抑制肿瘤生长并促进肿瘤细胞凋亡。结果基于涉及Keap1-PGAM5复合物的机制,提供了对ponicidin抗HCC特性的了解。
Ponicidin is a diterpenoid with demonstrated antitumor activity in clinical trials. However, the specific function and mechanism of action against hepatocellular carcinoma (HCC) remain unknown. In this study, it is found that ponicidin significantly inhibited the proliferation and migration of HCC cells. It is shown that ponicidin targets
Keap1 and promotes the formation of the
Keap1-PGAM5 complex, leading to the ubiquitination of PGAM5, using biotin-labeled ponicidin for target fishing and the HuProtTM Human Proteome Microarray V4.0. Ponicidin is found to activate the cysteine-dependent mitochondrial pathway via PGAM5, resulting in mitochondrial damage and ROS production, thereby promoting mitochondrial apoptosis in HepG2 cells. The first in vitro cocrystal structure of the PGAM5 IE 12-mer peptide and the
Keap1 Kelch domain is obtained. Using molecular dynamics simulations to confirm the binding of ponicidin to the
Keap1-PGAM5 complex. Based on the depth-based dynamic simulation, it is found that ponicidin can induce the tightening of the
Keap1-PGAM5 interaction pocket, thereby stabilizing the formation of the protein complex. Finally, it is observed that ponicidin effectively inhibited tumor growth and promoted tumor cell apoptosis in a BALB/c nude mouse xenograft tumor model. The results provide insight into the anti-HCC properties of ponicidin based on a mechanism involving the
Keap1-PGAM5 complex.