CYTOMORPHOLOGICAL EVALUATION OF PANCREATIC CELLS IN RESPONSE TO GLUCOSE CHALLENGE

Abstract

PANC-1 is a human pleiomorphic epithelioid carcinoma of the exocrine pancreas. Previous studies in our laboratory provided evidence that these cells can be manipulated into insulin-producing cells by altering the culture medium with increasing amounts of glucose. There is a paucity in the literature regarding cytomorphologic characteristics of PANC-1 cells under normal culture conditions and when challenged with increased amounts of glucose. The goal of this experiment was to evaluate the nuclear and cytoplasmic characteristics of PANC-1 cells. Initially, cells were grown in flasks with a control medium and then split into four separate groups containing control media or media containing an extra 1%, 2.5%, or 5% glucose. 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 and cytomorphology were compared at all phases. Nominal data were analyzed using non-parametric statistics calculating mean ranks to compare all four groups using the Kruskal-Wallace H statistic. While we saw statistically significant differences in most variables by glucose concentration at 24-, 48-, and 72-hours, the most telling was the increased glucose concentration detected by immunohistochemistry at all three phases rising from baseline, peaking at 2.5% glucose concentration, and rapidly declining to baseline levels indicating an inhibiting or toxic effect at 5% extra glucose (p<.0.05). This pattern was also consistent in the cytomorphologic changes observed as glucose concentrations increased and were more apparent by the 72-hour phase. This study contributes valuable quantitative data regarding the viability and function of PANC-1 cells as insulin-producing cells with increasing glucose challenge and demonstrates that PANC-1 or similar cells can be further engineered into useful components in drug delivery applications.