Skip to main content
eScholarship
Open Access Publications from the University of California

A HIF1alpha regulatory loop links hypoxia and mitochondrial signals in pheochromocytomas.

  • Author(s): Dahia, Patricia LM
  • Ross, Ken N
  • Wright, Matthew E
  • Hayashida, César Y
  • Santagata, Sandro
  • Barontini, Marta
  • Kung, Andrew L
  • Sanso, Gabriela
  • Powers, James F
  • Tischler, Arthur S
  • Hodin, Richard
  • Heitritter, Shannon
  • Moore, Francis
  • Dluhy, Robert
  • Sosa, Julie Ann
  • Ocal, I Tolgay
  • Benn, Diana E
  • Marsh, Deborah J
  • Robinson, Bruce G
  • Schneider, Katherine
  • Garber, Judy
  • Arum, Seth M
  • Korbonits, Márta
  • Grossman, Ashley
  • Pigny, Pascal
  • Toledo, Sérgio PA
  • Nosé, Vania
  • Li, Cheng
  • Stiles, Charles D
  • et al.
Abstract

Pheochromocytomas are neural crest-derived tumors that arise from inherited or sporadic mutations in at least six independent genes. The proteins encoded by these multiple genes regulate distinct functions. We show here a functional link between tumors with VHL mutations and those with disruption of the genes encoding for succinate dehydrogenase (SDH) subunits B (SDHB) and D (SDHD). A transcription profile of reduced oxidoreductase is detected in all three of these tumor types, together with an angiogenesis/hypoxia profile typical of VHL dysfunction. The oxidoreductase defect, not previously detected in VHL-null tumors, is explained by suppression of the SDHB protein, a component of mitochondrial complex II. The decrease in SDHB is also noted in tumors with SDHD mutations. Gain-of-function and loss-of-function analyses show that the link between hypoxia signals (via VHL) and mitochondrial signals (via SDH) is mediated by HIF1alpha. These findings explain the shared features of pheochromocytomas with VHL and SDH mutations and suggest an additional mechanism for increased HIF1alpha activity in tumors.

Many UC-authored scholarly publications are freely available on this site because of the UC's open access policies. Let us know how this access is important for you.

Main Content
Current View