title: The BRAF Inhibitor Vemurafenib Activates Mitochondrial Metabolism and Inhibits Hyperpolarized Pyruvate-Lactate Exchange in BRAF-Mutant Human Melanoma Cells.
abstract: Understanding the impact of BRAF signaling inhibition in human melanoma on key disease mechanisms is important for developing biomarkers of therapeutic response and combination strategies to improve long-term disease control. This work investigates the downstream metabolic consequences of BRAF inhibition with vemurafenib, the molecular and biochemical processes that underpin them, their significance for antineoplastic activity, and potential as noninvasive imaging response biomarkers.1H NMR spectroscopy showed that vemurafenib decreases the glycolytic activity of BRAF-mutant (WM266.4 and SKMEL28) but not BRAFWT(CHL-1 and D04) human melanoma cells. In WM266.4 cells, this was associated with increased acetate, glycine, and myo-inositol levels and decreased fatty acyl signals, while the bioenergetic status was maintained.13C NMR metabolic flux analysis of treated WM266.4 cells revealed inhibition of de novo lactate synthesis and glucose utilization, associated with increased oxidative and anaplerotic pyruvate carboxylase mitochondrial metabolism and decreased lipid synthesis. This metabolic shift was associated with depletion of hexokinase 2, acyl-CoA dehydrogenase 9, 3-phosphoglycerate dehydrogenase, and monocarboxylate transporters (MCT) 1 and 4 in BRAF-mutant but not BRAFWTcells and, interestingly, decreased BRAF-mutant cell dependency on glucose and glutamine for growth. Further, the reduction in MCT1 expression observed led to inhibition of hyperpolarized13C-pyruvate-lactate exchange, a parameter that is translatable to in vivo imaging studies, in live WM266.4 cells. In conclusion, our data provide new insights into the molecular and metabolic consequences of BRAF inhibition in BRAF-driven human melanoma cells that may have potential for combinatorial therapeutic targeting as well as noninvasive imaging of response. Mol Cancer Ther; 15(12); 2987-99. ©2016 AACR.
authors.affiliation: Cancer Research UK Cancer Imaging Centre, The Institute of Cancer Research, London, United Kingdom.
authors.forename: Teresa
authors.initials: T
authors.lastname: Delgado-Goni
authors.affiliation: Cancer Research UK Cancer Imaging Centre, The Institute of Cancer Research, London, United Kingdom.
authors.forename: Maria Falck
authors.initials: MF
authors.lastname: Miniotis
authors.affiliation: Cancer Research UK Cancer Imaging Centre, The Institute of Cancer Research, London, United Kingdom.
authors.forename: Slawomir
authors.initials: S
authors.lastname: Wantuch
authors.affiliation: Cancer Research UK Cancer Imaging Centre, The Institute of Cancer Research, London, United Kingdom.
authors.forename: Harold G
authors.initials: HG
authors.lastname: Parkes
authors.affiliation: Cancer Research UK Manchester Institute, Manchester, United Kingdom.
authors.forename: Richard
authors.initials: R
authors.lastname: Marais
authors.affiliation: Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, United Kingdom.
authors.forename: Paul
authors.initials: P
authors.lastname: Workman
authors.affiliation: Cancer Research UK Cancer Imaging Centre, The Institute of Cancer Research, London, United Kingdom. Mounia.Beloueche-Babari@icr.ac.uk Martin.Leach@icr.ac.uk.
authors.forename: Martin O
authors.initials: MO
authors.lastname: Leach
authors.affiliation: Cancer Research UK Cancer Imaging Centre, The Institute of Cancer Research, London, United Kingdom. Mounia.Beloueche-Babari@icr.ac.uk Martin.Leach@icr.ac.uk.
authors.forename: Mounia
authors.initials: M
authors.lastname: Beloueche-Babari
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D045744:Cell Line, Tumor; D004734:Energy Metabolism / Q000187:drug effects / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D005947:Glucose / Q000378:metabolism; D006801:Humans; D007211:Indoles / Q000494:pharmacology*; D007773:Lactates / Q000378:metabolism*; D008545:Melanoma / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D055432:Metabolomics / Q000379:methods; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism*; D008954:Models, Biological; D009154:Mutation; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D011766:Pyruvate Carboxylase / Q000378:metabolism; D019289:Pyruvic Acid / Q000378:metabolism*; D013449:Sulfonamides / Q000494:pharmacology*; D000077484:Vemurafenib
chemical_list: D000970:Antineoplastic Agents; D007211:Indoles; D007773:Lactates; D013449:Sulfonamides; D000077484:Vemurafenib; D019289:Pyruvic Acid; D048493:Proto-Oncogene Proteins B-raf; D011766:Pyruvate Carboxylase; D005947:Glucose