IMR Press / FBE / Volume 3 / Issue 1 / DOI: 10.2741/E233

Frontiers in Bioscience-Elite (FBE) is published by IMR Press from Volume 13 Issue 2 (2021). Previous articles were published by another publisher on a subscription basis, and they are hosted by IMR Press on imrpress.com as a courtesy and upon agreement with Frontiers in Bioscience.

Open Access Article
Alterations of respiratory chain complexes in sporadic pheochromocytoma
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1 Department of Pediatrics, University Hospital Salzburg, Paracelsus Medical University, Muellner Hauptstr. 48, A-5020 Salzburg, Austria
2 Department of Pathology, University Hospital Salzburg, Paracelsus Medical University, Muellner Hauptstr. 48, A-5020 Salzburg, Austria
3 Institute of Pathology, Medical University of Graz, A-8036 Graz, Austria

*Author to whom correspondence should be addressed.

Academic Editor: Anna Czarnecka

Front. Biosci. (Elite Ed) 2011, 3(1), 194–200; https://doi.org/10.2741/E233
Published: 1 January 2011
(This article belongs to the Special Issue Frontiers in molecular medicine)
Abstract

Succinate dehydrogenase (SDH) has been associated with carcinogenesis in hereditary pheochromocytoma (PC) and paraganglioma. We investigated if a similar association applies to sporadic pheochromocytoma. No genetic alteration was found in the SDHB, SDHC or SDHD genes of sporadic PC. However, in eight of nine sporadic PCs the SDH activity was, on average, reduced by 40%; moreover, the activities of the other oxidative phosphorylation (OXPHOS) complexes and citrate synthase were significantly lower compared to normal kidney tissue. Furthermore, immunohistochemical staining revealed a significant down-regulation of respiratory chain complexes. Since no pathogenic mutations were detected in the von Hippel-Lindau (VHL) gene, we can rule out that VHL deficiency is causing the general reduction of OXPHOS enzymes observed in the PCs investigated. In contrast to the single enzyme defects found in a subset hereditary PCs, a more generalized reduction of mitochondrial respiration seems to be present in most sporadic PCs. Strikingly, one of the nine PCs showed specific loss of complex I and a compensatory up-regulation of complexes II-V, which is a phenotype usually characteristic of oncocytic tumors.

Keywords
Respiratory Chain
Oxidative Phosphorylation
Energy Metabolism
Succinate Dehydrogenase
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