Masanori Murakami1, Na Sun2,1, Christian Greunke2, Annette Feuchtinger2, Stefan Kircher3, Timo Deutschbein4,5, Thomas Papathomas6, Nicole Bechmann7,8,9,10, Paal William Wallace7, Mirko Peitzsch7, Esther Korpershoek11, Juliane Friemel12, Anne-Paule Gimenez-Roqueplo13,14, Mercedes Robledo15, Henri J L M Timmers16, Letizia Canu17, Achim Weber12, Ronald R de Krijger18,19, Martin Fassnacht4,20, Thomas Knösel21, Thomas Kirchner21, Martin Reincke1, Axel Karl Walch2, Matthias Kroiss1,4,20, Felix Beuschlein1,22. 1. Medizinische Klinik und Poliklinik IV, Klinikum der Ludwig-Maximilians-Universität München, Munich, Germany. 2. Research Unit Analytical Pathology, German Research Center for Environmental Health (GmbH), Helmholtz Zentrum München, Neuherberg, Germany. 3. Institute for Pathology, University of Würzburg, Würzburg, Germany. 4. Department of Internal Medicine I, Division of Endocrinology and Diabetology, University Hospital Würzburg, University of Würzburg, Würzburg, Germany. 5. Medicover Oldenburg MVZ, Oldenburg, Germany. 6. Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, UK. 7. Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Carl Gustav Carus, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany. 8. Department of Medicine III, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany. 9. Department of Experimental Diabetology, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany. 10. German Center for Diabetes Research (DZD), München-Neuherberg, Germany. 11. Department of Pathology, Erasmus MC Cancer Institute, University Medical Center Rotterdam, Rotterdam, The Netherlands. 12. Institute for Pathology and Molecular Pathology, Universitätsspital Zürich, Zurich, Switzerland. 13. Université de Paris, PARCC, INSERM, Equipe labellisée par la Ligue contre le Cancer, Paris, France. 14. Genetics department, AP-HP, Hôpital européen Georges Pompidou, Paris, France. 15. Hereditary Endocrine Cancer Group, CNIO, Madrid, Spain and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain. 16. Department of Medicine, Division of Endocrinology, Radboud University Medical Center, Nijmegen, the Netherlands. 17. Department of Experimental and Clinical Biomedical Sciences 'Mario Serio', University of Florence, Florence, Italy. 18. Department of Pathology, University Medical Center Utrecht, Utrecht, the Netherlands. 19. Princess Máxima Center for Pediatric Oncology, Utrecht, the Netherlands. 20. Comprehensive Cancer Center Mainfranken, University of Würzburg, Würzburg, Germany. 21. Institute of Pathology, Ludwig-Maximilians-Universität München, Munich, Germany. 22. Department of Endocrinology, Diabetology and Clinical Nutrition, Universitätsspital Zürich, Zurich, Switzerland.
Abstract
OBJECTIVE: Within the past decade, important genetic drivers of pheochromocytoma and paraganglioma (PPGLs) development have been identified. The pathophysiological mechanism that translates these alterations into functional autonomy and potentially malignant behavior has not been elucidated in detail. Here we used MALDI-mass spectrometry imaging (MALDI-MSI) of formalin-fixed paraffin-embedded tissue specimens to comprehensively characterize the metabolic profiles of PPGLs. DESIGN AND METHODS: MALDI-MSI was conducted in 344 PPGLs and results correlated with genetic and phenotypic information. We experimentally silenced genetic drivers by siRNA in PC12 cells to confirm their metabolic impact in vitro. RESULTS: Tissue abundance of kynurenine pathway metabolites such as xanthurenic acid was significantly lower (P = 2.35E-09) in the pseudohypoxia pathway cluster 1 compared to PPGLs of the kinase-driven PPGLs cluster 2. Lower abundance of xanthurenic acid was associated with shorter metastasis-free survival (log-rank tests P = 7.96E-06) and identified as a risk factor for metastasis independent of the genetic status (hazard ratio, 32.6, P = 0.002). Knockdown of Sdhb and Vhl in an in vitro model demonstrated that inositol metabolism and sialic acids were similarly modulated as in tumors of the respective cluster. CONCLUSIONS: The present study has identified distinct tissue metabolomic profiles of PPGLs in relation to tumor genotypes. In addition, we revealed significantly altered metabolites in the kynurenine pathway in metastatic PPGLs, which can aid in the prediction of its malignant potential. However, further validation studies will be required to confirm our findings.
OBJECTIVE: Within the past decade, important genetic drivers of pheochromocytoma and paraganglioma (PPGLs) development have been identified. The pathophysiological mechanism that translates these alterations into functional autonomy and potentially malignant behavior has not been elucidated in detail. Here we used MALDI-mass spectrometry imaging (MALDI-MSI) of formalin-fixed paraffin-embedded tissue specimens to comprehensively characterize the metabolic profiles of PPGLs. DESIGN AND METHODS: MALDI-MSI was conducted in 344 PPGLs and results correlated with genetic and phenotypic information. We experimentally silenced genetic drivers by siRNA in PC12 cells to confirm their metabolic impact in vitro. RESULTS: Tissue abundance of kynurenine pathway metabolites such as xanthurenic acid was significantly lower (P = 2.35E-09) in the pseudohypoxia pathway cluster 1 compared to PPGLs of the kinase-driven PPGLs cluster 2. Lower abundance of xanthurenic acid was associated with shorter metastasis-free survival (log-rank tests P = 7.96E-06) and identified as a risk factor for metastasis independent of the genetic status (hazard ratio, 32.6, P = 0.002). Knockdown of Sdhb and Vhl in an in vitro model demonstrated that inositol metabolism and sialic acids were similarly modulated as in tumors of the respective cluster. CONCLUSIONS: The present study has identified distinct tissue metabolomic profiles of PPGLs in relation to tumor genotypes. In addition, we revealed significantly altered metabolites in the kynurenine pathway in metastatic PPGLs, which can aid in the prediction of its malignant potential. However, further validation studies will be required to confirm our findings.