Potent antiproliferative effect of fatty-acid derivative AIC-47 on leukemic mice harboring BCR-ABL mutation

Therapy based on targeted inhibition of BCR-ABL tyrosine kinase has greatly improved the prognosis for patients with Philadelphia chromosome (Ph)-positive leukemia and tyrosine kinase inhibitors (TKI) have become standard therapy. However, some patients acquire resistance to TKI that is frequently associated with point mutations in BCR-ABL. We previously reported that a medium-chain fatty-acid derivative AIC-47 induced transcriptional suppression of BCR-ABL and perturbation of the Warburg effect, leading to growth inhibition in Ph-positive leukemia cells. Herein, we showed that AIC-47 had anti-leukemic effects in either wild type (WT)- or mutated-BCR-ABL-harboring cells. AIC-47 suppressed transcription of BCR-ABL gene regardless of the mutation through downregulation of transcriptional activator, c-Myc. Reprogramming of the metabolic pathway has been reported to be associated with resistance to anti-cancer drugs; however, we found that a point mutation of BCR-ABL was independent of the profile of pyruvate kinase muscle (PKM) isoform expression. Even in T315I-mutated cells, AIC-47 induced switching of the expression profile of PKM isoforms from PKM2 to PKM1, suggesting that AIC-47 disrupted the Warburg effect. In a leukemic mouse model, AIC-47 greatly suppressed the increase in BCR-ABL mRNA level and improved hepatosplenomegaly regardless of the BCR-ABL mutation. Notably, the improvement of splenomegaly by AIC-47 was remarkable and might be equal to or greater than that of TKI. These findings suggest that AIC-47 might be a promising agent for overcoming the resistance of Ph-positive leukemia to therapy.