POB is a transition state-based, cell permeable pro-drug inhibitor of ODC, a key enzyme involved in polyamine synthesis and a potential cancer drug target. Intracellularly, POB is phosphorylated by pyridoxal kinase and the methyl ester hydrolyzed. This active inhibitor most likely binds apo-ODC resulting in greatly reduced ODC activity and inhibition of cellular proliferation. POB was able to inhibit proliferation in a wide variety of tumor cell lines: LN229 (IC50 = 50 μM), Jurkat, COS7, SW2 and both high and low-grade glioblastoma multiforme. More potent than DFMO.
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