We have preliminarily established that bladder cancer cell lines are uniquely sensitive to glutamine levels in their media and to a greater extent than glucose levels. Also, we have obtained metabolomic data on the metabolites for bladder cancer cell lines that differ in MTAP deletion status and p53 status. We are exploring certain pathways identified from this work as potentially targetable. We have begun to test the use of lactase dehydrogenase inhibitors developed by NCATS and Dr. Len Neckers in bladder cancer cell lines. We have also previously evaluated the use of fatty acid synthase inhibitors and shown that bladder cancer cell lines respond effectively to such inhibitors as well. Recently, we have successfully investigated the metabolic phenotype of 15 bladder cancer cell lines using the seahorse analyzer. We found that the majority of cell lines undergo oxidative phosphorylation and shift towards glycolysis when stressed under hypoxia through rates of OCR and ECR on the Seahorse analyzer. We have characterized their lactate production under various conditions as well. We have established that lactate dehydrogenase inhibitors can be quite effective in glycolytic cell lines and that metformin can be quite effective in oxidative phosphorylation-dependent cell lines. Moreover, treatment with metformin can induce sensitivity to lactate dehydrogenase inhibitors in oxidative phosphorylation-dependent cell lines. We are now attempting to silence lactate dehydrogenase and see if the effects are similar as seen with pharmacologic inhibition. We have completed animal studies that demonstrate that the combination of metformin and LDH inhibitors are synergistic. Also we have embarked upon a new pathway to manipulate, the NAMPT pathway that regenerates NAD+/NADH. We have been using selective inhibitors of NAMPT and found impressive results both invitro and in a preclinical xenograft model. We are working with a company on a CRADA to see if we possibly use this drug moving forward in a Phase I clinical trial.
