410 Background: Bladder cancer remains the fourth most common cancer in American males with a higher risk of recurrence and progression for patients with diabetes mellitus. Urothelial bladder cancer is characterized by aerobic glycolysis with upregulation of glycolytic enzymes (known as the Warburg effect) such as phosphoglycerate mutase. Phosphoglycerate mutase 2 (PGAM2), a reversible glycolytic enzyme expressed highly in muscle, represents a target for modulation because of its differential expression from another isoform, phosphoglycerate mutase 1. PGAM2 knockdown may impact bladder cancer growth significantly via its effect on glucose metabolism at different glucose concentrations seen in patients with diabetes mellitus. Methods: UM-UC3 bladder cancer cells were assessed for PGAM2 expression at different glucose concentrations via Western blot and quantitative PCR. One native UM-UC3 line, three PGAM2 knockdown lines, and one vector control cell line were included in the western blot study. Cellular proliferation was analyzed using an enzyme based hexoseaminidase assay and was further supported with an automated cell counter. The effects of cisplatin were also investigated. Results: Increased PGAM2 expression at increased glucose concentrations in UM-UC3 was confirmed by Western blot and quantitative PCR. PGAM2 knockdown cells responded differently to changes in glucose concentration compared to the control cell lines, with a large increase in growth at a low glucose level of 25mg/dL after day 4. Cell proliferation demonstrated similar growth between the knockdown and controls at higher glucose concentrations of 100 and 200mg/dL. Proliferation data using automated cell counter demonstrate the same growth trend. Conclusions: Increased cell growth of PGAM2 knockdowns, most notably at 25mg/dL, suggests that PGAM2 may play a different role in glycolysis than expected, possibly serving as a modulator in cell growth instead of a simple reversible enzyme. We are currently investigating its differential expression compared to PGAM1, an enzyme recently characterized to have an opposite effect to PGAM2.
Expression of Ral GTPases, Their Effectors, and Activators in Human Bladder Cancer
