Evaluation of insulin secretion by pancreatic cells in response to increasing amounts of glucose.
Panc-1 is a human pleiomorphic epithelioid carcinoma of the exocrine pancreas. There is evidence these cells can be manipulated into insulin producing cells, by transfection with an insulin promoter or by altering the culture medium. In experiments where the cultures were altered, the insulin secreting cell types were aggregates of round cells not stellate shaped cells. The goal of this experiment was to select for survival of the round phenotype by altering glucose concentrations and to evaluate glucose dependent insulin secretion. Initially cells were grown in flasks with control medium, and then split into three separate groups containing control media, or media containing an extra 2.5% or 5% glucose. After selection for round phenotypes, the cells were maintained in control media for several passages. Cells from the three cultures were plated (1 x 105 cells/well) and treated with control, 1%, 2.5%, or 5% glucose for 24, 48, and 72 hours. Cells and supernatants were harvested and cell number, cellular glutathione, morphology, and insulin levels were determined. Control cells grown in 2.5 or 5% glucose showed significant decreases in cell number at 48-72 hours. Glutathione levels decreased as malondialdehyde (MDA) levels increased. Cells grown initially in 2.5 or 5% glucose were not affected significantly by increasing glucose concentrations. Evaluation of insulin production by enzyme linked immuno sorbent assay (ELISA) showed trends of dose and time dependency in all groups, with the highest levels in cells grown at 5% glucose and treated with 5% glucose. Overall, it appears Panc-1 cells can be converted into insulin producing cell types.
Hamil
Lamar
L
School of Health Related Professions, Department of Orthopaedic Surgery and Rehabilitation, University of Mississippi Medical Center, Jackson, MS, 39216, USA. ghamil@shrp.umsmed.edu.
Benghuzzi
Ham
H
Tucci
Michelle
M