Abstract
In the RIP1-Tag2 mouse model of pancreatic islet carcinoma, angiogenesis is switched on in a discrete premalignant stage of tumor development, persisting thereafter. Signaling through VEGF receptor tyrosine kinases is a well-established component of angiogenic regulation. We show that five VEGF ligand genes are expressed in normal islets and throughout islet tumorigenesis. To begin dissecting their contributions, we produced an islet beta cell specific knockout of VEGF-A, resulting in islets with reduced vascularity but largely normal physiology. In RIP1-Tag2 mice wherein most oncogene-expressing cells had deleted the VEGF-A gene, both angiogenic switching and tumor growth were severely disrupted, as was the neovasculature. Thus, VEGF-A is crucial for angiogenesis in a prototypical model of carcinogenesis, whose loss is not readily compensated.
Publication types
- Research Support, U.S. Gov't, P.H.S.
MeSH terms
- Animals
- Cell Division
- Endothelial Growth Factors / genetics
- Endothelial Growth Factors / metabolism*
- GTPase-Activating Proteins / metabolism
- Gene Deletion
- Gene Expression Profiling
- Humans
- Islets of Langerhans / blood supply*
- Islets of Langerhans / metabolism*
- Islets of Langerhans / pathology
- Lymphokines / genetics
- Lymphokines / metabolism
- Mice
- Mice, Transgenic
- Neovascularization, Pathologic / genetics
- Neovascularization, Pathologic / metabolism*
- Organ Specificity
- Pancreatic Neoplasms / blood supply*
- Pancreatic Neoplasms / genetics
- Pancreatic Neoplasms / metabolism*
- Pancreatic Neoplasms / pathology
- Reverse Transcriptase Polymerase Chain Reaction
- Vascular Endothelial Growth Factor A
- Vascular Endothelial Growth Factors
Substances
- Endothelial Growth Factors
- GTPase-Activating Proteins
- Lymphokines
- Ralbp1 protein, mouse
- Vascular Endothelial Growth Factor A
- Vascular Endothelial Growth Factors