Childhood leukemia arises from hematopoietic stem cells by induction of mutations. Quite often chromosomal translocations arise prenatally as first key event in multistage process of leukemogenesis. These translocations result in so called preleukemic gene fusions (PGFs), such as BCR-ABL and TEL-AML1, which generate hybrid proteins with altered properties. Critical DNA damage resulting in translocations are DNA double-strand breaks (DSBs). BCR-ABL and TEL-AML1 were shown to be associated with increased constitutive DSBs in various model systems. We analyzed cells from peripheral blood and CD34-/CD34+ cells from bone marrow of pediatric acute lymphoblastic leukemia (ALL) patients harboring BCR-ABL or TEL-AML1. We used sensitive technique that is based on automated enumeration of DSB co-localizing proteins γH2AX and 53BP1, which form so called DNA repair foci. We found that level of constitutive γH2AX/53BP1 foci is significantly higher in cells of ALL pediatric patients than in healthy subjects. There was also significant increased level of constitutive γH2AX/53BP1 foci in cells from ALL patients harboring BCR-ABL or TEL-AML1 compared to patients without PGFs. The same increase was observed regardless cell type for both PGFs. Our data on increased DSB levels in the BCR-ABL/TEL-AML1 patient's cells support a model where BCR-ABL/TEL-AML1 induces DNA instability through facilitating mutagenesis and appearance of additional genetic alterations driving leukemogenesis.
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http://dx.doi.org/10.4149/neo_2014_076 | DOI Listing |
Zhongguo Shi Yan Xue Ye Xue Za Zhi
December 2022
Department of Pediatrics, The Affiliated Hospital of Southwest Medical University (Birth Defects Clinical Medical Research Center of Sichuan Province), Luzhou 646000, Sichuan Province, China.
Curr Med Sci
February 2022
Department of Pediatric Hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
J Mol Diagn
October 2021
Division of Hematology-Oncology, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan. Electronic address:
Cytometry B Clin Cytom
July 2021
Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, Canada.
Background: B-lymphoblastic leukemia (B-ALL) is the most common childhood malignancy, and its diagnosis requires immunophenotypically demonstrating blast B cell lineage differentiation. Expression of myeloperoxidase (MPO) in B-ALL is well-described and it has been recognized that a diagnosis of mixed phenotype acute leukemia should be made cautiously if MPO expression is the sole myeloid feature in these cases. We sought to determine whether MPO expression in pediatric B-ALL was associated with differences in laboratory, immunophenotypic, or clinical features.
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December 2020
Department of Pediatric, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
Acute lymphocytic leukemia is the most common leukemia in children. Many studies suggest the existence of two subsequent hits in order for the disease to occur. TEL-AML1 (ETV6-RUNX1) is considered an initial genetic hit that occurs prenatally and generates a pre-leukemia clone.
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