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Physiological Concentrations of Insulin Augment Pancreatic Cancer Cell Proliferation and Glucose Utilization By Activating MAP Kinase, PI3 Kinase and Enhancing GLUT-1 Expression
- Source :
- Pancreas. 21:310-320
- Publication Year :
- 2000
- Publisher :
- Ovid Technologies (Wolters Kluwer Health), 2000.
-
Abstract
- Pancreatic carcinoma is characterized by poor prognosis and lack of response to conventional therapy for reasons that are not clear. Because of the structural relationship between the exocrine and endocrine pancreas and high concentrations of islet hormones bathing pancreatic tissue, we hypothesized that pancreatic cancer cell proliferation and glucose utilization are regulated by pancreatic islet hormones, particularly insulin. Based on this, the effect of islet hormones on pancreatic cancer cells in vitro was investigated. Five pancreatic cancer cell lines, CD11, CD18, HPAF, PANC-1, and MiaPaCa2 were used to investigate the effect of islet hormones on cell proliferation, glucose utilization, and GLUT-1 expression. Insulin, but not somatostatin and glucagon, induced pancreatic cancer cell growth in a concentration- and time-dependent manner. At concentrations within the range of those in the intrapancreatic vasculature, insulin (10(-10)-10(-8) mol/L) markedly increased [3H]-thymidine incorporation. Insulin significantly enhanced glucose utilization of pancreatic cancer cells before it enhanced cell proliferation. The MAPK kinase inhibitor PD 098059 abolished insulin-stimulated DNA synthesis and partially reduced insulin-stimulated glucose uptake. In contrast, the PI3 kinase inhibitor wortmannin substantially inhibited insulin-induced glucose uptake and partially blocked thymidine incorporation. Furthermore, after 24-hour treatment with insulin, GLUT-I expression in pancreatic cancer cells was markedly increased, indicating that insulin enhances glucose utilization partly through increasing glucose transport. These findings suggest that insulin stimulates proliferation and glucose utilization in pancreatic cancer cells by two distinct pathways. Insulin augments DNA synthesis mainly by MAP kinase activation and glucose uptake mainly by PI3 kinase activation and enhancement of GLUT-I expression. High intrapancreatic concentrations of insulin are likely to play an important role in stimulating pancreatic cancer growth indirectly by increasing substrate availability as well as by direct action as a trophic factor.
- Subjects :
- medicine.medical_specialty
Pancreatic disease
Monosaccharide Transport Proteins
Endocrinology, Diabetes and Metabolism
medicine.medical_treatment
Glucose uptake
Phosphatidylinositol 3-Kinases
Endocrinology
Internal medicine
Tumor Cells, Cultured
Internal Medicine
medicine
Humans
Insulin
Enzyme Inhibitors
Pancreatic hormone
Phosphoinositide-3 Kinase Inhibitors
Flavonoids
Glucose Transporter Type 1
Hepatology
biology
Glucose transporter
DNA, Neoplasm
Glucagon
medicine.disease
Insulin oscillation
Androstadienes
Enzyme Activation
Pancreatic Neoplasms
Insulin receptor
Glucose
medicine.anatomical_structure
biology.protein
Mitogen-Activated Protein Kinases
Somatostatin
Wortmannin
Pancreas
Protein Kinases
Cell Division
Subjects
Details
- ISSN :
- 08853177
- Volume :
- 21
- Database :
- OpenAIRE
- Journal :
- Pancreas
- Accession number :
- edsair.doi.dedup.....10679eb6b42ca3d05d96850e0b1cc50e