EglN3 hydroxylase stabilizes BIM-EL linking VHL type 2C mutations to pheochromocytoma pathogenesis and chemotherapy resistance

• Published in: Proceedings of the National Academy of Sciences - PNAS 2019-08, Vol.116 (34), p.16997-17006
• Main Authors: Li, Shuijie, Rodriguez, Javier, Li, Wenyu, Bullova, Petra, Fell, Stuart M., Surova, Olga, Westerlund, Isabelle, Topcic, Danijal, Bergsland, Maria, Stenman, Adam, Muhr, Jonas, Nistér, Monica, Holmberg, Johan, Juhlin, C. Christofer, Larsson, Catharina, von Kriegsheim, Alex, Kaelin, William G., Schlisio, Susanne
• Format: Article
• Language: English
• Subjects: Adrenal Gland Neoplasms - drug therapy; Adrenal Gland Neoplasms - genetics; Adrenal Gland Neoplasms - metabolism; Adrenal Gland Neoplasms - pathology; Animals; Apoptosis; Apoptosis - drug effects; Apoptosis - genetics; Bcl-2-Like Protein 11 - genetics; Bcl-2-Like Protein 11 - metabolism; BIM protein; Biological Sciences; Cell Hypoxia - drug effects; Cell Hypoxia - genetics; Cell survival; Chemoresistance; Chemotherapy; Cisplatin; Cisplatin - pharmacology; Drug Resistance, Neoplasm - drug effects; Drug Resistance, Neoplasm - genetics; Extracellular signal-regulated kinase; Genotypes; Humans; Hydroxylase; Hydroxylation - drug effects; Hydroxylation - genetics; Hypoxia-Inducible Factor-Proline Dioxygenases - genetics; Hypoxia-Inducible Factor-Proline Dioxygenases - metabolism; Kinases; MAP Kinase Signaling System - drug effects; MAP Kinase Signaling System - genetics; Medicin och hälsovetenskap; Mice; Mice, Knockout; Mutation; Oxygen; Pathogenesis; PC12 Cells; Phenotypes; Pheochromocytoma; Pheochromocytoma - drug therapy; Pheochromocytoma - metabolism; Pheochromocytoma - pathology; Phosphorylation; PNAS Plus; Proteasomes; Proteins; Proteolysis - drug effects; Rats; VHL protein; Von Hippel-Lindau Tumor Suppressor Protein - genetics; Von Hippel-Lindau Tumor Suppressor Protein - metabolism
• ISSN: 0027-8424; 1091-6490; 1091-6490
• DOI: 10.1073/pnas.1900748116

Despite the discovery of the oxygen-sensitive regulation of HIFα by the von Hippel–Lindau (VHL) protein, the mechanisms underlying the complex genotype/phenotype correlations in VHL disease remain unknown. Some germline VHL mutations cause familial pheochromocytoma and encode proteins that preserve their ability to down-regulate HIFα. While type 1, 2A, and 2B VHL mutants are defective in regulating HIFα, type 2C mutants encode proteins that preserve their ability to down-regulate HIFα. Here, we identified an oxygen-sensitive function of VHL that is abolished by VHL type 2C mutations. We found that BIM-EL, a proapoptotic BH3- only protein, is hydroxylated by EglN3 and subsequently bound by VHL. VHL mutants fail to bind hydroxylated BIM-EL, regardless of whether they have the ability to bind hydroxylated HIFα or not. VHL binding inhibits BIM-EL phosphorylation by extracellular signal-related kinase (ERK) on serine 69. This causes BIM-EL to escape from proteasomal degradation, allowing it to enhance EglN3-induced apoptosis. BIM-EL was rapidly degraded in cells lacking wild-type VHL or in which EglN3 was inactivated genetically or by lack of oxygen, leading to enhanced cell survival and chemotherapy resistance. Combination therapy using ERK inhibitors, however, resensitizes VHL- and EglN3-deficient cells that are otherwise cisplatin-resistant.