Increased HIF1 alpha in SDH and FH deficient tumors does not cause microsatellite instability.

Abstract

Germline mutations in nuclear genes encoding mitochondrial enzymes fumarate hydratase (FH) and succinate dehydrogenase (subunits SDHB/C/D) have been implicated in the development of tumor syndromes referred to as hereditary leiomyomatosis and renal cell cancer (HLRCC) and hereditary paragangliomatosis (HPGL), respectively. FH and SDH are operating in the tricarboxylic acid cycle (the TCA cycle, the Krebs cycle). In the FH and SDH deficient tumors, accumulation of the substrates, fumarate and succinate, has been shown to cause stabilization of hypoxia inducible factor 1 alpha (HIF1 alpha). According to recent studies, HIF1 alpha could contribute to the hypoxia induced genomic instability seen in many cancers, through repression of mismatch repair (MMR) protein MSH2. In this study, in agreement with previous works, we found HIF1 alpha to be moderately or highly stabilized in 67% (16/24) and 77% (48/62) of HLRCC tumors and SDHB/C/D paragangliomas (PGL) and pheochromocytomas (PHEO), respectively. In addition, a set of 54 other familial and nonfamilial PGLs/PHEOs were studied. Moderately or highly stabilized HIF1 alpha was present in 68% (26/38) of the PGLs but in PHEOs (n = 16) no such pattern was observed. We then analyzed the suggested link between HIF1 alpha stabilization and MSH2 repression, in HLRCC and HPGL tumor material. No microsatellite instability (MSI) or lack of MSH2 expression was, however, observed. Thus we failed to provide in vivo evidence for the proposed link between HIF1 alpha stabilization and functional MMR deficiency, in TCAC deficient tumors.

• Authors: Heli J Lehtonen, Markus J Mäkinen, Maija Kiuru, Päivi Laiho, Riitta Herva, Ivonne van Minderhout, Pancras C W Hogendoorn, Cees Cornelisse, Peter Devilee, Virpi Launonen, Lauri A Aaltonen
• Journal: International journal of cancer (Int J Cancer) Vol. 121 Issue 6 Pg. 1386-9 (Sep 15 2007) ISSN: 0020-7136 [Print] United States
• PMID: 17520677 (Publication Type: Journal Article)
• Copyright: (c) 2007 Wiley-Liss, Inc.

Chemical References

• HIF1A protein, human
• Hypoxia-Inducible Factor 1, alpha Subunit
• Succinate Dehydrogenase
• MSH2 protein, human
• MutS Homolog 2 Protein
• Fumarate Hydratase

Topics

• Carcinoma, Renal Cell (genetics, metabolism)
• Citric Acid Cycle (physiology)
• Fumarate Hydratase (deficiency, genetics)
• Germ-Line Mutation
• Humans
• Hypoxia-Inducible Factor 1, alpha Subunit (metabolism)
• Immunohistochemistry
• Kidney Neoplasms (genetics, metabolism)
• Leiomyomatosis (genetics, metabolism)
• Microsatellite Instability
• MutS Homolog 2 Protein (metabolism)
• Neoplastic Syndromes, Hereditary (genetics, metabolism)
• Paraganglioma (genetics, metabolism)
• Pheochromocytoma (genetics, metabolism)
• Succinate Dehydrogenase (deficiency, genetics)
• Tissue Array Analysis