title: Efficacy of the polo-like kinase inhibitor rigosertib, alone or in combination with Abelson tyrosine kinase inhibitors, against break point cluster region-c-Abelson-positive leukemia cells.
abstract: The potency of Abelson (ABL) tyrosine kinase inhibitors (TKIs) against chronic myeloid leukemia (CML) has been demonstrated. However, ABL TKI resistance can develop. In this study, we investigated the efficacy of a combination therapy including rigosertib (ON 01910.Na), a polo-like kinase (PLK) and phosphoinositide 3-kinase (PI3K) inhibitor, and ABL TKIs. A 72-h rigosertib treatment was found to inhibit cell growth, induce apoptosis, reduce phosphorylation of the breakpoint cluster region-c (BCR)-ABL and its substrate Crk-L, and increase the activities of caspase 3 and poly (ADP-ribose) polymerase (PARP). This combination therapy also exerted a synergistic inhibitory effect on Philadelphia chromosome (Ph)-positive cell proliferation and reduced the phosphorylation of BCR-ABL and Crk-L while increasing that of cleaved PARP and the H2A.X histone. Rigosertib also potently inhibited the growth of ABL TKI-resistant cells, and cotreatment with ABL TKIs and rigosertib induced higher cytotoxicity. These results indicate that rigosertib treatment may be a powerful strategy against ABL TKI-resistant cells and could enhance the cytotoxic effects of ABL TKIs.
authors.affiliation: Department of Hematology, Tokyo Medical University, Tokyo, Japan.
authors.forename: Seiichi
authors.initials: S
authors.lastname: Okabe
authors.affiliation: Department of Hematology, Tokyo Medical University, Tokyo, Japan.
authors.forename: Tetsuzo
authors.initials: T
authors.lastname: Tauchi
authors.affiliation: Department of Hematology, Tokyo Medical University, Tokyo, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Tanaka
authors.affiliation: Department of Hematology, Tokyo Medical University, Tokyo, Japan.
authors.forename: Juri
authors.initials: J
authors.lastname: Sakuta
authors.affiliation: Department of Hematology, Tokyo Medical University, Tokyo, Japan.
authors.forename: Kazuma
authors.initials: K
authors.lastname: Ohyashiki
mesh_terms: D017209:Apoptosis; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D005998:Glycine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000188:drug therapy*; D047428:Protein Kinase Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use*; D013450:Sulfones / Q000008:administration & dosage / Q000627:therapeutic use*; D014162:Transfection
chemical_list: D047428:Protein Kinase Inhibitors; D013450:Sulfones; C507134:ON 01910; D005998:Glycine
keywords: ABL tyrosine kinase inhibitor; chronic myeloid leukemia; polo-like kinase; resistant cell