Anticancer effects of some novel dichloroacetophenones through the inhibition of pyruvate dehydrogenase kinase 1.

Targeting pyruvate dehydrogenase kinase 1 (PDK1) has been suggested as a potential anticancer strategy. 2,2-dichloroacetophenone (DAP) is a PDK1 inhibitor exhibiting weak anticancer potency and poor selectivity. The current study describes the characterization of three potent compounds 54, 55 and 64, which tightly bound to PDK1 with Kd values of 1.29, 0.97, and 0.58 μM, respectively, and activated pyruvate dehydrogenase complex with EC50 values of 0.68, 0.49, and 0.33 μM, respectively. In contrast with DAP, these analogues were more potent and selective against PDK1, reduced proliferation and survival of NCI-H1975 cells, and suppressed tumor growth in a NCI-H1975 xenograft mouse model. Moreover, compounds 54, 55 and 64 depolarized mitochondrial membrane potential, induced cell apoptosis, decreased extracellular lactate formation, and increased reactive oxygen species production in NCI-H1975 cells. They may serve as potential modulators to regulate mitochondrial function and reprogram metabolism in cancer cells which could represent promising compounds for further development of potent PDK1 inhibitors.