Bcr/abl gene is derived from the t(9;22) reciprocal translocation and is present in most of chronic myelogenous leukemia (CML) and a cohort of acute lymphoblastic leukemia (ALL) patients. BCR/ABL oncogenic tyrosine kinase modulates response to DNA damage inducing resistance to genotoxic therapies. In addition BCR/ABL stimulates genomic instability, which may lead to mutations in BCR/ABL kinase causing resistance to imatinib mesylate. We hypothesize that: BCR/ABL elevates the levels of reactive oxygen species (ROS) which induce "spontaneous" DNA lesions (for example uracil residues), whose unfaithful repair introduces amino acid substitutions in the BCR/ABL kinase domain causing resistance to IM. The role of ROS in generation of oxidative DNA damage leading to mutagenesis and resistance to imatinib mesylate will be studied in CML hematopoietic stem cells (HSC), common myeloid progenitor cells (CMP), and granulocyte/macrophage progenitor cells (GMP) using anti-oxidant approaches and in vitro and in vivo models of BCR/ABL leukemogenesis. The efficiency and fidelity of the mechanisms processing ROS-dependent oxidative DNA damage in BCR/ABL leukemia cells will be determined by studying base excision repair (BER), focusing on UDG glycosylase removing uracil residues. These reactions will be examined using well-defined reporter/substrate systems and a combination of different approaches including immunofluorescence, phosphorylation-less and interaction- deprived mutants, transgenic mice, and sequencing. BCR/ABL-UDG functional interaction will be investigated by mutagenesis and targeted by aptamers to inhibit resistance to imatinib mesylate.

Public Health Relevance

Imatinib mesylate (IM) revolutionized the treatment of BCR/ABL-positive leukemias such as chronic myelogenous leukemia (CML) and a cohort of acute lymphocytic leukemias (ALL). Unfortunately, reactive oxygen species (ROS) cause amino acid substitutions in the BCR/ABL kinase domain resulting in resistance to IM. We will determine if anti-oxidants are able to reduce mutations and IM resistance. In addition, we will examine the role of base excision repair in generation of these mutations. Results of our studies may lead to better treatment of BCR/ABL-positive leukemias.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA123014-05
Application #
8206819
Study Section
Hematopoiesis Study Section (HP)
Program Officer
Mufson, R Allan
Project Start
2008-02-01
Project End
2012-12-31
Budget Start
2012-01-01
Budget End
2012-12-31
Support Year
5
Fiscal Year
2012
Total Cost
$400,685
Indirect Cost
$133,562
Name
Temple University
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
057123192
City
Philadelphia
State
PA
Country
United States
Zip Code
19122
Podszywalow-Bartnicka, Paulina; Wolczyk, Magdalena; Kusio-Kobialka, Monika et al. (2014) Downregulation of BRCA1 protein in BCR-ABL1 leukemia cells depends on stress-triggered TIAR-mediated suppression of translation. Cell Cycle 13:3727-41
Slupianek, A; Falinski, R; Znojek, P et al. (2013) BCR-ABL1 kinase inhibits uracil DNA glycosylase UNG2 to enhance oxidative DNA damage and stimulate genomic instability. Leukemia 27:629-34
Nieborowska-Skorska, M; Hoser, G; Hochhaus, A et al. (2013) Anti-oxidant vitamin E prevents accumulation of imatinib-resistant BCR-ABL1 kinase mutations in CML-CP xenografts in NSG mice. Leukemia 27:2253-4
Bolton-Gillespie, Elisabeth; Schemionek, Mirle; Klein, Hans-Ulrich et al. (2013) Genomic instability may originate from imatinib-refractory chronic myeloid leukemia stem cells. Blood 121:4175-83
Van Etten, Richard A; Mauro, Michael; Radich, Jerald P et al. (2013) Advances in the biology and therapy of chronic myeloid leukemia: proceedings from the 6th Post-ASH International Chronic Myeloid Leukemia and Myeloproliferative Neoplasms Workshop. Leuk Lymphoma 54:1151-8
Falinski, Rafal; Nieborowska-Skorska, Margaret; Skorski, Tomasz (2012) BCR-ABL1 kinase facilitates localization of acetylated histones 3 and 4 on DNA double-strand breaks. Leuk Res 36:241-4
Nieborowska-Skorska, Margaret; Kopinski, Piotr K; Ray, Regina et al. (2012) Rac2-MRC-cIII-generated ROS cause genomic instability in chronic myeloid leukemia stem cells and primitive progenitors. Blood 119:4253-63
Flis, Krzysztof; Irvine, David; Copland, Mhairi et al. (2012) Chronic myeloid leukemia stem cells display alterations in expression of genes involved in oxidative phosphorylation. Leuk Lymphoma 53:2474-8
Skorski, Tomasz (2012) Genetic mechanisms of chronic myeloid leukemia blastic transformation. Curr Hematol Malig Rep 7:87-93
Slupianek, Artur; Dasgupta, Yashodhara; Ren, Shu-Yue et al. (2011) Targeting RAD51 phosphotyrosine-315 to prevent unfaithful recombination repair in BCR-ABL1 leukemia. Blood 118:1062-8

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