In vitro anti-leukemia activity of dual PI3K/mTOR inhibitor Voxtalisib on HL60 and K562 cells, as well as their multidrug resistance counterparts HL60/ADR and K562/A02 cells.

Current treatment strategies for leukemia still have some limitations such as severe side effects and drug resistance. Less toxic and more effective drugs for leukemia patients are therefore expected. In the present study, the efficacy of a dual PI3K/mTOR inhibitor, Voxtalisib, on acute myeloid leukemia (AML) cell line HL60 and chronic myeloid leukemia (CML) cell line K562, as well as their Adriamycin (ADR)-selected multi drug resistance (MDR) counterparts HL60/ADR and K562/A02, was investigated. Voxtalisib exhibited potent anti-proliferative activity on these four cell lines dose-dependently, with IC50 values as 2.23 μM for HL60, 4.79 μM for HL60/ADR, 4.20 μM for K562 and 3.90 μM for K562/A02 cells. Voxtalisib arrested cell cycle progression at G1 phase in all cell lines by upregulating p27, downregulating cyclin D1 and p-pRb. When combined with ADR, Voxtalisib reversed the ADR-resistance of HL60/ADR and K562/A02 cells, possibly by reducing MDR1 and MRP1 expression. In conclusion, Voxtalisib showed anti-leukemia activity on AML and CML cell lines as well as their multidrug resistant ones, suggesting Voxtalisib might become a promising drug candidate for therapy of AML and CML in the future.