title: In vivo HIF-mediated reductive carboxylation is regulated by citrate levels and sensitizes VHL-deficient cells to glutamine deprivation.
abstract: Hypoxic and VHL-deficient cells use glutamine to generate citrate and lipids through reductive carboxylation (RC) of α-ketoglutarate. To gain insights into the role of HIF and the molecular mechanisms underlying RC, we took advantage of a panel of disease-associated VHL mutants and showed that HIF expression is necessary and sufficient for the induction of RC in human renal cell carcinoma (RCC) cells. HIF expression drastically reduced intracellular citrate levels. Feeding VHL-deficient RCC cells with acetate or citrate or knocking down PDK-1 and ACLY restored citrate levels and suppressed RC. These data suggest that HIF-induced low intracellular citrate levels promote the reductive flux by mass action to maintain lipogenesis. Using [(1-13)C]glutamine, we demonstrated in vivo RC activity in VHL-deficient tumors growing as xenografts in mice. Lastly, HIF rendered VHL-deficient cells sensitive to glutamine deprivation in vitro, and systemic administration of glutaminase inhibitors suppressed the growth of RCC cells as mice xenografts.
authors.affiliation: Center for Cancer Research, Massachusetts General Hospital Cancer Center, Charlestown, MA 02129, USA.
authors.forename: Paulo A
authors.initials: PA
authors.lastname: Gameiro
authors.forename: Juanjuan
authors.initials: J
authors.lastname: Yang
authors.forename: Ana M
authors.initials: AM
authors.lastname: Metelo
authors.forename: Rocio
authors.initials: R
authors.lastname: Pérez-Carro
authors.forename: Rania
authors.initials: R
authors.lastname: Baker
authors.forename: Zongwei
authors.initials: Z
authors.lastname: Wang
authors.forename: Alexandra
authors.initials: A
authors.lastname: Arreola
authors.forename: W Kimryn
authors.initials: WK
authors.lastname: Rathmell
authors.forename: Aria
authors.initials: A
authors.lastname: Olumi
authors.forename: Pilar
authors.initials: P
authors.lastname: López-Larrubia
authors.forename: Gregory
authors.initials: G
authors.lastname: Stephanopoulos
authors.forename: Othon
authors.initials: O
authors.lastname: Iliopoulos
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism*; D002247:Carbon Isotopes / Q000378:metabolism; D002264:Carboxylic Acids / Q000378:metabolism; D002292:Carcinoma, Renal Cell / Q000378:metabolism*; D045744:Cell Line, Tumor; D002951:Citrates / Q000378:metabolism*; D045604:Extracellular Fluid / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry; D005973:Glutamine / Q000172:deficiency*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D008954:Models, Biological; D010084:Oxidation-Reduction; D051794:Von Hippel-Lindau Tumor Suppressor Protein / Q000378:metabolism*; D000099162:Endothelial PAS Domain-Containing Protein 1
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D002247:Carbon Isotopes; D002264:Carboxylic Acids; D002951:Citrates; D005973:Glutamine; D051794:Von Hippel-Lindau Tumor Suppressor Protein; D000099162:Endothelial PAS Domain-Containing Protein 1; C497446:VHL protein, human