Reference SummaryYu R, PLoS One 2011;6(8):e23397

Title

Pancreatic neuroendocrine tumors in glucagon receptor-deficient mice.

Authors

Yu R; Dhall D; Nissen NN; Zhou C; Ren SG

Journal

PLoS One

Volume

6

Issue

8

Year

2011

Pages

e23397

Abstract

Inhibition of glucagon signaling causes hyperglucagonemia and pancreatic alpha cell hyperplasia in mice. We have recently demonstrated that a patient with an inactivating glucagon receptor mutation (P86S) also exhibits hyperglucagonemia and pancreatic alpha cell hyperplasia but further develops pancreatic neuroendocrine tumors (PNETs). To test the hypothesis that defective glucagon signaling causes PNETs, we studied the pancreata of mice deficient in glucagon receptor (Gcgr(-/-)) from 2 to 12 months, using WT and heterozygous mice as controls. At 2-3 months, Gcgr(-/-) mice exhibited normal islet morphology but the islets were mostly composed of alpha cells. At 5-7 months, dysplastic islets were evident in Gcgr(-/-) mice but absent in WT or heterozygous controls. At 10-12 months, gross PNETs (>/=1 mm) were detected in most Gcgr(-/-) pancreata and micro-PNETs (<1 mm) were found in all (n = 14), whereas the islet morphology remained normal and no PNETs were found in any WT (n = 10) or heterozygous (n = 25) pancreata. Most PNETs in Gcgr(-/-) mice were glucagonomas, but some were non-functioning. No tumors predominantly expressed insulin, pancreatic polypeptide, or somatostatin, although some harbored focal aggregates of tumor cells expressing one of those hormones. The PNETs in Gcgr(-/-) mice were well differentiated and occasionally metastasized to the liver. Menin expression was aberrant in most dysplatic islets and PNETs. Vascular endothelial growth factor (VEGF) was overexpressed in PNET cells and its receptor Flk-1 was found in the abundant blood vessels or blood islands inside the tumors. We conclude that defective glucagon signaling causes PNETs in the Gcgr(-/-) mice, which may be used as a model of human PNETs. Our results further suggest that completely inhibiting glucagon signaling may not be a safe approach to treat diabetes.

Links

J:176507 – MGI References
21853126 – National Library of Medicine/PubMed

Models

Strain Model Name Treatment Agent(s) Organ Affected Frequency Model Details
DBA/1LacJ-Gcgrtm1Jcp Pancreas - Islet of Langerhans - Alpha cell tumor - neuroendocrine Pancreas - Islet of Langerhans - Alpha cell

high

DBA/1LacJ-Gcgrtm1Jcp Pancreas - Islet of Langerhans - Beta cell tumor - neuroendocrine Pancreas - Islet of Langerhans - Beta cell

7.14

DBA/1LacJ-Gcgrtm1Jcp Pancreas - Islet of Langerhans dysplasia Pancreas - Islet of Langerhans

high - 100

DBA/1LacJ Pancreas - Islet of Langerhans dysplasia Pancreas - Islet of Langerhans

0

DBA/1LacJ-Gcgrtm1Jcp/+ Pancreas - Islet of Langerhans dysplasia Pancreas - Islet of Langerhans

0

DBA/1LacJ-Gcgrtm1Jcp Pancreas - Islet of Langerhans hyperplasia Pancreas - Islet of Langerhans

100

DBA/1LacJ Pancreas - Islet of Langerhans hyperplasia Pancreas - Islet of Langerhans

0

DBA/1LacJ-Gcgrtm1Jcp/+ Pancreas - Islet of Langerhans hyperplasia Pancreas - Islet of Langerhans

0

DBA/1LacJ-Gcgrtm1Jcp Pancreas - Islet of Langerhans tumor - neuroendocrine Pancreas - Islet of Langerhans

1.92 - 100

DBA/1LacJ Pancreas - Islet of Langerhans tumor - neuroendocrine Pancreas - Islet of Langerhans

0

DBA/1LacJ-Gcgrtm1Jcp/+ Pancreas - Islet of Langerhans tumor - neuroendocrine Pancreas - Islet of Langerhans

0

DBA/1LacJ (Unspecified organ) tumor - unclassified (Unspecified organ)

0

DBA/1LacJ-Gcgrtm1Jcp/+ (Unspecified organ) tumor - unclassified (Unspecified organ)

0.9