GSE177485
Dihydroorotate dehydrogenase inhibition reveals metabolic vulnerability in chronic myeloid leukemia
The development of different generations of BCR-ABL1 tyrosine kinases inhibitors (TKIs) has led the overall survival (OS) of the chronic myeloid leukemia (CML) patients to become almost similar to that of a control population without leukemia, but the TKI therapy can be successfully discontinued only in half of those who are achieving a deep molecular response, that  eans in approximately 15-20% of the entire population. In addition, although few, there are CML patients who show resistance to TKI therapy, are prone to progress to more advanced phases of the disease and die of CML related causes. Therefore, implementing an alternative approach for targeting TKI resistant leukemic cells would be of the essence in trying to solve these problems. Dihydroorotate dehydrogenase (DHODH) is a druggable enzyme in the de novo pyrimidine biosynthesis pathway that is located in the inner membrane of mitochondria. Here, we found that CML CD34+ cells and CML cell lines are vulnerable to DHODH inhibition mediated by Meds433, a new and potent DHODH inhibitor recently developed by our group. Meds433 significantly activated the apoptotic pathway and suppressed cell growth of CML cells in vitro and in vivo in a xenograft mice model. Moreover, inhibition of DHODH led to the reduction of amino acids and induction of huge metabolic stress in CML CD34+. Altogether, our study shows that targeting pyrimidine synthesis is a promising approach for targeting CML stem/progenitor cells, helping more patients to achieve good molecular response and possibly successful treatment discontinuation. Overall design: Gene expression profiling was performed on CD34+ cells from five CML patients, untreated, and after three days of treatment with Meds433 100nM, for a total of 10 matched samples.