Targeting heme Oxygenase-1 with hybrid compounds to overcome Imatinib resistance in chronic myeloid leukemia cell lines

Heme oxygenase-1 (HO-1) is a cytoprotective enzyme and a survival-enhancing factor in a number of cancers. Chronic myeloid leukemia (CML) is a blood cancer caused by pathological kinase activity of the BCR-ABL protein, currently treated with tyrosine kinase inhibitors (TKIs) such as Imatinib (IM). However, resistance to TKIs persists in a number of patients and HO-1 overexpression has been linked with the induction of chemoresistance in CML. With this in mind, in this study, we designed and synthesized the first series of hybrid compounds obtained by combining the structures of IM, as BCR-ABL inhibitor, with imidazole-based HO-1 inhibitors. We found that many hybrids were able to inhibit the enzymatic activity of both targets and to reduce the viability of CML-IM resistant cells, showing that a single molecular entity may reduce the resistance phenomenon.