ORIGINAL ARTICLE Antileukemic activity of the HSP70 inhibitor pifithrin-l in acute leukemia

Heat shock protein (HSP) 70 is aberrantly expressed in different malignancies and has emerged as a promising new target for anticancer therapy. Here, we analyzed the in vitro antileukemic effects of pifithrin-l (PFT-l), an inhibitor of inducible HSP70, in acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) cell lines, as well as in primary AML blasts. PFT-l significantly inhibited cell viability at low micromolar concentrations in all cell lines tested, with IC50 values ranging from 2.5