Characterizing Vmax of Glycolytic Enzymes in Insulin Treated EC Ishikawa Cells
Faculty Mentor Information
Dr. Jennifer Chase, Northwest Nazarene University
Presentation Date
7-15-2026
Abstract
Insulin is a risk factor for endometrial cancer (EC) and promotes growth in EC cell lines. We found that insulin treatment of Ishikawa endometrial cells decreases glycolysis and may increase glycogen synthesis. We hypothesized that insulin downregulates glycolytic enzymes while upregulating glycogen synthesis enzymes. Vmax values were measured in enzymes harvested from serum-starved Ishikawa cells treated with insulin or sham for 24 h. Enzyme activities (nmol/min/mg protein) were calculated from ΔA340 in coupled assays producing or consuming NADH or NADPH, and protein concentration was determined by BCA assay. Insulin significantly increased the Vmax of phosphoglucose isomerase (F6P→G6P) and lactate dehydrogenase (pyruvate→lactate), contrary to our prediction. No significant changes were observed for the remaining enzymes, although the study was underpowered and additional measurements are ongoing, including enzymes involved in glycogen metabolism. These findings suggest that the reduced glycolytic rate is not primarily driven by altered enzyme activity but instead by other insulin-regulated pathways. Therefore, strategies targeting glycolytic enzymes alone may have limited efficacy in slowing endometrial cancer progression.
Characterizing Vmax of Glycolytic Enzymes in Insulin Treated EC Ishikawa Cells
Insulin is a risk factor for endometrial cancer (EC) and promotes growth in EC cell lines. We found that insulin treatment of Ishikawa endometrial cells decreases glycolysis and may increase glycogen synthesis. We hypothesized that insulin downregulates glycolytic enzymes while upregulating glycogen synthesis enzymes. Vmax values were measured in enzymes harvested from serum-starved Ishikawa cells treated with insulin or sham for 24 h. Enzyme activities (nmol/min/mg protein) were calculated from ΔA340 in coupled assays producing or consuming NADH or NADPH, and protein concentration was determined by BCA assay. Insulin significantly increased the Vmax of phosphoglucose isomerase (F6P→G6P) and lactate dehydrogenase (pyruvate→lactate), contrary to our prediction. No significant changes were observed for the remaining enzymes, although the study was underpowered and additional measurements are ongoing, including enzymes involved in glycogen metabolism. These findings suggest that the reduced glycolytic rate is not primarily driven by altered enzyme activity but instead by other insulin-regulated pathways. Therefore, strategies targeting glycolytic enzymes alone may have limited efficacy in slowing endometrial cancer progression.