title: ATM function and its relationship with ATM gene mutations in chronic lymphocytic leukemia with the recurrent deletion (11q22.3-23.2).
abstract: Approximately 10-20% of chronic lymphocytic leukemia (CLL) patients exhibit del(11q22-23) before treatment, this cohort increases to over 40% upon progression following chemoimmunotherapy. The coding sequence of the DNA damage response gene, ataxia-telangiectasia-mutated (ATM), is contained in this deletion. The residual ATM allele is frequently mutated, suggesting a relationship between gene function and clinical response. To investigate this possibility, we sought to develop and validate an assay for the function of ATM protein in these patients. SMC1 (structural maintenance of chromosomes 1) and KAP1 (KRAB-associated protein 1) were found to be unique substrates of ATM kinase by immunoblot detection following ionizing radiation. Using a pool of eight fluorescence in situ hybridization-negative CLL samples as a standard, the phosphorylation of SMC1 and KAP1 from 46 del (11q22-23) samples was analyzed using normal mixture model-based clustering. This identified 13 samples (28%) that were deficient in ATM function. Targeted sequencing of the ATM gene of these samples, with reference to genomic DNA, revealed 12 somatic mutations and 15 germline mutations in these samples. No strong correlation was observed between ATM mutation and function. Therefore, mutation status may not be taken as an indicator of ATM function. Rather, a direct assay of the kinase activity should be used in the development of therapies.
authors: Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors: Y
authors: Y
authors: Jiang
authors: Department of Biostatistics, Houston, TX, USA.
authors: H-C
authors: HC
authors: Chen
authors: Department of Bioinformatics and Computational Biology, Houston, TX, USA.
authors: X
authors: X
authors: Su
authors: Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors: P A
authors: PA
authors: Thompson
authors: Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors: X
authors: X
authors: Liu
authors: Department of Biostatistics, Houston, TX, USA.
authors: K-A
authors: KA
authors: Do
authors: Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors: W
authors: W
authors: Wierda
authors: Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors: M J
authors: MJ
authors: Keating
authors: Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.|Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors: W
authors: W
authors: Plunkett
mesh_terms: D064007:Ataxia Telangiectasia Mutated Proteins / Q000235:genetics* / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000378:metabolism; D045744:Cell Line, Tumor; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D002872:Chromosome Deletion; D002880:Chromosomes, Human, Pair 11; D019175:DNA Methylation; D017353:Gene Deletion; D018095:Germ-Line Mutation; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000235:genetics* / Q000378:metabolism*; D009154:Mutation; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D000076183:Tripartite Motif-Containing Protein 28 / Q000378:metabolism; D000098550:Structural Maintenance of Chromosome Protein 1
chemical_list: D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D000098550:Structural Maintenance of Chromosome Protein 1; C101116:TRIM28 protein, human; D000076183:Tripartite Motif-Containing Protein 28; D064007:Ataxia Telangiectasia Mutated Proteins