[PMC free article] [PubMed] [CrossRef] [Google Scholar] 21

[PMC free article] [PubMed] [CrossRef] [Google Scholar] 21. antioxidants. S3QEL specific inhibitor of site IIIQo, at Complex III prevented depolarization induced by X1. JNK inhibition by JNK inhibitors VIII and SP600125 also prevented mitochondrial depolarization. After X1, triggered JNK translocated to mitochondria as assessed by proximity ligation assays. Tat-Sab KIM1, a peptide selectively preventing the binding of JNK the outer mitochondrial membrane protein Sab, clogged the depolarization induced by X1 and sorafenib. X1 advertised cell death mostly by necroptosis that was partially prevented by JNK inhibition. These results indicate that JNK activation and translocation to mitochondria is definitely a common mechanism of mitochondrial dysfunction induced by both VDAC opening and sorafenib. Keywords: Hepatocarcinoma, JNK, Mitochondria, Mitochondrial membrane potential, ROS, Sab, Sorafenib, VDAC Graphical Abstract 1.?Intro Hepatocellular carcinoma (HCC), the most common malignancy of the liver remains the second leading cause of cancer-related deaths (1). Chemotherapeutic options for advanced phases are limited and restricted to sorafenib (SOR) and most recently, lenvatinib (2, 3). For both medicines, the efficacy is definitely poor (4, Clavulanic acid 5). SOR is definitely a multikinase inhibitor that blocks signaling pathways relevant to tumor growth and angiogenesis including vascular endothelial growth element receptors (VEGFR 1C3), platelet-derived growth element- (PDGF-), the small GRP-binding protein Ras, the serine/threonine-specific protein kinases Raf, and the extracellular signal-regulated kinase ERK (6C8). Several reports have also shown effects of SOR on mitochondrial rate of metabolism including dissipation of mitochondrial membrane potential () and inhibition of ATP synthesis (9C13). The bioenergetics of malignancy cells is driven both by glycolysis and mitochondrial rate of metabolism. The Warburg phenotype characterized by suppression of mitochondrial rate of metabolism and enhanced aerobic glycolysis accounts for 20C90% of ATP formation in malignancy cells (14, 15). Beyond variations in energy production, the current consensus is that the Warburg phenotype facilitates the generation of carbon backbones for the synthesis of biomass (lipids, peptides, and nucleic acids) to sustain cell growth (16C19). Although much research efforts has been directed to inhibit glycolysis as an anti-cancer strategy, in the last decade, mitochondrial rate Clavulanic acid of metabolism has become a potential Clavulanic acid target for the development novel cancer treatments (20). Moreover, the metabolic flexibility of tumors, that switch between glycolytic and oxidative phenotypes depending on several factors including pharmacological interventions, opens new options for developing medicines focusing on mitochondria (20, 21). The mostly anionic mitochondrial metabolites like respiratory substrates, ATP, ADP and Pi mix the mitochondrial outer membrane through a single pathway, the voltage dependent anion channel (VDAC), to then mix the inner membrane by a Clavulanic acid variety of individual service providers and transporters. Once in the mitochondrial matrix, respiratory substrates gas the Krebs cycle generating the reducing equivalents, nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FADH2). Both NADH and FADH2 are oxidized in the electron transport chain (complexes I-IV) to the final acceptor molecular oxygen that is reduced to water (22). The circulation of electrons at Complexes I, III, and IV produces protons that are pumped to the intermembrane space to produce a proton motive push (p = ?59pH), which is used from the ATP F1-FO synthase to generate ATP from ADP and Pi. , the main component of p, serves as a valuable readout of overall mitochondrial rate of metabolism under different experimental conditions in intact cells. Rules of movement of respiratory substrates and additional metabolites through VDAC globally controls mitochondrial rate of metabolism. Thus, rules of VDAC opening modulates mitochondrial rate of metabolism and cellular bioenergetics (23, 24). Previously, we showed that free tubulin closes VDAC and decreases mitochondrial rate of metabolism. We also shown that erastin, a VDAC binding protein, blocks the inhibitory effect of tubulin on VDAC (25C27). More recently, in TM4SF20 a high throughput screening of 50,000 small molecules, we recognized a series of erastin-like compounds that increase mitochondrial rate of metabolism and decrease glycolysis in HCC cells. The most potent erastin-like compound recognized was the quinazolinone 5-chloro-N-[4-chloro-3-(trifluoromethyl) pheyl]-2-(ethylsulfonyl)-4-pyrimidinecarboxamide (X1) that.