title: MYC in chronic myeloid leukemia: induction of aberrant DNA synthesis and association with poor response to imatinib.
abstract: Untreated chronic myeloid leukemia (CML) progresses from chronic phase to blastic crisis (BC). Increased genomic instability, deregulated proliferation, and loss of differentiation appear associated to BC, but the molecular alterations underlying the progression of CML are poorly characterized. MYC oncogene is frequently deregulated in human cancer, often associated with tumor progression. Genomic instability and induction of aberrant DNA replication are described as effects of MYC. In this report, we studied MYC activities in CML cell lines with conditional MYC expression with and without exposure to imatinib, the front-line drug in CML therapy. In cells with conditional MYC expression, MYC did not rescue the proliferation arrest mediated by imatinib but provoked aberrant DNA synthesis and accumulation of cells with 4C content. We studied MYC mRNA expression in 66 CML patients at different phases of the disease, and we found that MYC expression was higher in CML patients at diagnosis than control bone marrows or in patients responding to imatinib. Further, high MYC levels at diagnosis correlated with a poor response to imatinib. MYC expression did not directly correlate with BCR-ABL levels in patients treated with imatinib. Overall our study suggests that, as in other tumor models, MYC-induced aberrant DNA synthesis in CML cells is consistent with MYC overexpression in untreated CML patients and nonresponding patients and supports a role for MYC in CML progression, possibly through promotion of genomic instability.
authors: Departamento de Biología Molecular, Facultad de Medicina, Instituto de Biomedicina y Biotecnología de Cantabria, Avda Cardenal Herrera Oria s/n, 39011 Santander, Spain.
authors: Marta
authors: M
authors: Albajar
authors: M Teresa
authors: MT
authors: Gómez-Casares
authors: Javier
authors: J
authors: Llorca
authors: Itsaso
authors: I
authors: Mauleon
authors: Jose P
authors: JP
authors: Vaqué
authors: Juan C
authors: JC
authors: Acosta
authors: Arancha
authors: A
authors: Bermúdez
authors: Nicholas
authors: N
authors: Donato
authors: M Dolores
authors: MD
authors: Delgado
authors: Javier
authors: J
authors: León
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use; D001549:Benzamides; D045744:Cell Line, Tumor; D004261:DNA Replication / Q000187:drug effects*; D018450:Disease Progression; D016044:Fusion Proteins, bcr-abl / Q000378:metabolism; D042822:Genomic Instability / Q000235:genetics; D006801:Humans; D000068877:Imatinib Mesylate; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000188:drug therapy* / Q000235:genetics* / Q000473:pathology; D010879:Piperazines / Q000627:therapeutic use*; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics / Q000378:metabolism*; D011743:Pyrimidines / Q000627:therapeutic use*
chemical_list: D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D047428:Protein Kinase Inhibitors; D016271:Proto-Oncogene Proteins c-myc; D011743:Pyrimidines; D000068877:Imatinib Mesylate; D011505:Protein-Tyrosine Kinases; D016044:Fusion Proteins, bcr-abl