Imatinib Mesylate Induces Cisplatin Hypersensitivity in Bcr-Abl+ Cells by Differential Modulation of p53 Transcriptional and Proapoptotic Activity

Posted by rob on December 18, 2009 under Uncategorized | Comments are off for this article

Imatinib is highly effective in inducing remission in chronic myelogenous leukemia (CML). However, complete eradication of the malignant clone by imatinib is rare. We investigated the efficacy of combining imatinib with cisplatin. Inhibition of Bcr-Abl by imatinib induced a hypersensitive phenotype both in Bcr-Abl+ cell lines and in CD34+ cells from CML patients. Importantly, cisplatin sensitivity of leukemic cells harboring an inactive Bcr-Abl greatly exceeded that of Bcr-Abl– parental cells. The cisplatin response of Bcr-Abl+ cells treated with imatinib was characterized by an impaired G2-M arrest and by rapid induction of mitochondrial cell death after the first passage through G2. Imatinib abrogated ATM activation on cisplatin selectively in Bcr-Abl+ cells. As a consequence, phos…
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