Cellular and Molecular Characterization of a Feline Insulinoma
Autor: | T. Schermerhorn, B.T. Jones, T.C. Jackson, S. Lindbloom-Hawley, B. Debey |
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Rok vydání: | 2009 |
Předmět: |
endocrine system
medicine.medical_specialty endocrine system diseases Gene Expression Biology Cat Diseases Polymerase Chain Reaction Glucagon chemistry.chemical_compound Hexokinase Insulin-Secreting Cells Internal medicine Glucokinase medicine Animals Insulin Pancreatic polypeptide Insulinoma Glucose Transporter Type 2 General Veterinary Chromogranin A DNA Neoplasm medicine.disease Immunohistochemistry Pancreatic Neoplasms medicine.anatomical_structure Endocrinology chemistry Cats biology.protein GLUT2 Pancreas |
Zdroj: | Journal of Veterinary Internal Medicine. 23:383-387 |
ISSN: | 1939-1676 0891-6640 |
DOI: | 10.1111/j.1939-1676.2008.0267.x |
Popis: | Background: Insulinoma is an autonomous insulin-secreting islet cell neoplasm that is rarely diagnosed in cats. The clinical and pathological aspects of feline insulinoma have been described previously, but the molecular characteristics of these tumors have not been investigated. Objectives: The study objectives were to characterize peptide hormone production and determine expression of selected genes involved in glucose metabolism and insulin secretion in a feline insulinoma. Methods: Immunohistochemistry and RT-PCR were used to examine hormone and gene expression, respectively, by insulinoma cells. Results: Immunohistochemistry examination indicated that the tumor cells expressed insulin, chromogranin A, and somatostatin but not glucagon or pancreatic polypeptide. The tumor expressed several genes characteristic of pancreatic beta cells (β cells) including insulin (INS), glucose transporter 2 (GLUT2), and glucokinase (GCK). The tumor also expressed hexokinase 1 (HK1), a glycolytic enzyme not normally expressed in β cells. GCK expression was higher in the insulinoma than in normal pancreas from the same cat. The GCK : HK1 ratio was >20-fold higher in insulinoma tissue than in normal pancreas. Conclusions and Clinical Importance: The feline insulinoma produced several peptide hormones and expressed genes consistent with a β-cell phenotype. The pattern of hexokinase gene expression in tumor cells differed from that of normal pancreas. These findings suggest insulinoma cells may have an increased sensitivity to glucose that could contribute to the abnormal insulin secretory response observed at low serum glucose concentrations. |
Databáze: | OpenAIRE |
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