Annexin A1 sustains tumor metabolism and cellular proliferation upon stable loss of HIF1A

// Nadine Rohwer 1, 2, 3, * , Fabian Bindel 4, * , Christina Grimm 5 , Suling J. Lin 6 , Jessica Wappler 13 , Bertram Klinger 7, 8 , Nils Blüthgen 7, 8 , Ilona Du Bois 9 , Bernd Schmeck 9 , Hans Lehrach 5 , Marjo de Graauw 10 , Emanuel Goncalves 11 , Julio Saez-Rodriguez 12 , Patrick Tan 6 , Heike I. Grabsch 13 , Alessandro Prigione 14 , Stefan Kempa 4, # , Thorsten Cramer 15, # 1 Hepatologie und Gastroenterologie, Campus Virchow-Klinikum, Charité, Berlin, Germany 2 German Cancer Consortium (DKTK), Heidelberg, Germany 3 German Cancer Research Center (DKFZ), Heidelberg, Germany 4 Berlin Institute for Medical Systems Biology, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany 5 Max-Planck-Institut for Molecular Genetics, Berlin, Germany 6 Duke-NUS Graduate Medical School, Singapore 7 Institute of Pathology, Charité - Universitätsmedizin Berlin, Berlin, Germany 8 Integrative Research Institute (IRI) for the Life Sciences and Institute for Theoretical Biology, Humboldt-Universität Berlin, Berlin, Germany 9 Institute for Lung Research, Universities of Giessen and Marburg Lung Center, Philipps-University, Marburg, Germany 10 Division of Toxicology, Leiden/Amsterdam Center for Drug Research, Leiden University, Amsterdam, The Netherlands 11 European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Cambridge, United Kingdom 12 Joint Research Centre for Computational Biomedicine (JRC-COMBINE), RWTH Aachen University, Faculty of Medicine, Aachen, Germany 13 GROW School of Oncology and Developmental Biology and Department of Pathology, Maastricht University Medical Center, Maastricht, The Netherlands 14 Max-Delbrück-Center for Molecular Medicine, Berlin, Germany 15 Molecular Tumor Biology, Department of General, Visceral and Transplantation Surgery, RWTH University Hospital, Aachen, Germany * These authors contributed equally to this work # These authors jointly directed this work Correspondence to: Thorsten Cramer, e-mail: tcramer@ukaachen.de Stefan Kempa, e-mail: stefan.kempa@mdc-berlin.de Keywords: cancer therapy, Annexin A1, cancer metabolism, HIF-1, induced essentiality Received: June 29, 2015 Accepted: December 08, 2015 Published: December 29, 2015 ABSTRACT Despite the approval of numerous molecular targeted drugs, long-term antiproliferative efficacy is rarely achieved and therapy resistance remains a central obstacle of cancer care. Combined inhibition of multiple cancer-driving pathways promises to improve antiproliferative efficacy. HIF-1 is a driver of gastric cancer and considered to be an attractive target for therapy. We noted that gastric cancer cells are able to functionally compensate the stable loss of HIF-1α. Via transcriptomics we identified a group of upregulated genes in HIF-1α-deficient cells and hypothesized that these genes confer survival upon HIF-1α loss. Strikingly, simultaneous knock-down of HIF-1α and Annexin A1 (ANXA1), one of the identified genes, resulted in complete cessation of proliferation. Using stable isotope-resolved metabolomics, oxidative and reductive glutamine metabolism was found to be significantly impaired in HIF-1α/ANXA1-deficient cells, potentially explaining the proliferation defect. In summary, we present a conceptually novel application of stable gene inactivation enabling in-depth deconstruction of resistance mechanisms. In theory, this experimental approach is applicable to any cancer-driving gene or pathway and promises to identify various new targets for combination therapies.