A zebrafish model to study and therapeutically manipulate hypoxia signaling in tumorigenesis.
Hypoxic signaling is a central modulator of cellular physiology in cancer. Core members of oxygen-sensing pathway including the von Hippel-Lindau tumor suppressor protein (pVHL) and the hypoxia inducible factor (HIF) transcription factors have been intensively studied, but improved organismal models might speed advances for both pathobiologic understanding and therapeutic modulation. To study HIF signaling during tumorigenesis and development in zebrafish, we developed a unique in vivo reporter for hypoxia, expressing EGFP driven by prolyl hydroxylase 3 (phd3) promoter/regulatory elements. Modulation of HIF pathway in Tg(phd3::EGFP) embryos showed a specific role for hypoxic signaling in the transgene activation. Zebrafish vhl mutants display a systemic hypoxia response, reflected by strong and ubiquitous transgene expression. In contrast to human VHL patients, heterozygous Vhl mice and vhl zebrafish are not predisposed to cancer. However, upon exposure to dimethylbenzanthracene (DMBA), the vhl heterozygous fish showed an increase in the occurrence of hepatic and intestinal tumors, a subset of which exhibited strong transgene expression, suggesting loss of Vhl function in these tumor cells. Compared with control fish, DMBA-treated vhl heterozygous fish also showed an increase in proliferating cell nuclear antigen-positive renal tubules. Taken together, our findings establish Vhl as a genuine tumor suppressor in zebrafish and offer this model as a tool to noninvasively study VHL and HIF signaling during tumorigenesis and development.
MRC Centre for Developmental and Biomedical Genetics, Department of Biomedical Science, Academic Unit of Respiratory Medicine, The University of Sheffield, Western Bank, Sheffield, United Kingdom.
Kirankumar
K
Santhakumar
Emma C
EC
Judson
Philip M
PM
Elks
Sarah
S
McKee
Stone
S
Elworthy
Ellen
E
van Rooijen
Sarah S
SS
Walmsley
Stephen A
SA
Renshaw
Simon S
SS
Cross
Fredericus J M
FJ
van Eeden
D015127:9,10-Dimethyl-1,2-benzanthracene; D000818:Animals; D015687:Cell Hypoxia / Q000187:drug effects / Q000502:physiology; D002471:Cell Transformation, Neoplastic / Q000139:chemically induced / Q000378:metabolism*; D004195:Disease Models, Animal; D051793:Hypoxia-Inducible Factor 1 / Q000378:metabolism; D007414:Intestinal Neoplasms / Q000139:chemically induced / Q000378:metabolism*; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced / Q000378:metabolism*; D015398:Signal Transduction; D025521:Tumor Suppressor Proteins / Q000378:metabolism; D029961:Zebrafish Proteins / Q000378:metabolism
D051793:Hypoxia-Inducible Factor 1; D025521:Tumor Suppressor Proteins; C542158:Vhl protein, zebrafish; D029961:Zebrafish Proteins; D015127:9,10-Dimethyl-1,2-benzanthracene