Metabolic Reprogramming of Urothelial Carcinoma—A Theragnostic Target for Betulinic Acid

A pivotal role of metabolic reprogramming in urothelial carcinoma is hallmarked by the dependence of two-fold faster proliferation of urothelial carcinoma cell line T24 than benign cell line TRT-HU1 on five-fold higher glucose (basal) 16 mM vs. 3 mM in McCoy's 5A media and Keratinocyte Serum Free media, respectively. Here, we report that an additional 10% increase to 17.6 mM and 3.3 mM glucose significantly shortens the doubling time by 3 h and 1 h for T24 and TRT-HUI, respectively. T24 grown at 17.6 mM glucose lowers the confocal localization of the fatty acid mimetic, Betulinic Acid (BA) conjugated to FITC (BA-FITC) with Mito Tracker Red (mitochondrial marker), which doubles the IC50 of BA and BA-FITC by lowering cell cycle arrest in the G0/G1 phase from 54.2% to 43.8% and caspase-3/7 mediated apoptosis and by reversing <i>caspase-3</i>, <i>p53</i>, <i>PTEN</i>, <i>GAPDH,</i> and <i>XIAP</i> gene expression induced by BA in T24 grown at basal glucose (16 mM). Besides slowing the glycogen and pH decline of T24 at basal glucose, BA exhibited an eight-fold higher IC50 than Mitomycin C (MC) on TRT-HU1 by not mimicking the glucose-insensitive cycle arrest and apoptosis of MC. Overall, the glucose sensitivity of the lower IC50 of BA-FITC and BA on T24 vs. TRT-HU1 supports the safety of BA conjugates for theragnostic purposes.