title: DNA-PK and ATM are required for radiation-enhanced integration.
abstract: Ionizing radiation is known to improve transfection of exogenous DNA, a process we have termed radiation-enhanced integration. Previous observations have demonstrated that Ku proteins are critical for radiation-enhanced integration. Since Ku proteins form the DNA-binding domain of DNA-PK and since DNA-PK is important in nonhomologous DNA end joining, it was hypothesized that DNA-PK function might be important for radiation-enhanced integration. The ATM protein has been shown to be important in the recognition of a variety of types of DNA damage and to associate with DNA-PK under certain conditions. It was thus hypothesized that ATM might also play a role in radiation-enhanced integration. To test these hypotheses, radiation-enhanced integration was measured in hamster cells that are defective in the catalytic subunit of DNA-PK and in human cells containing mutant ATM. Radiation-enhanced integration was not detected in any of the cell lines with mutant PRKDC (also known as DNA-PKcs), but it was present in cells of the same lineage with wild-type PRKDC. Radiation-enhanced integration was defective in cells lacking kinase activation. ATM-deficient cell lines also showed defective radiation-enhanced integration. These data demonstrate that DNA-PK and ATM must both be active for radiation-enhanced integration to be observed.
authors.affiliation: Department of Experimental Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030, USA.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Nimura
authors.forename: Sheikh M
authors.initials: SM
authors.lastname: Ismail
authors.forename: Akihiro
authors.initials: A
authors.lastname: Kurimas
authors.forename: David J
authors.initials: DJ
authors.lastname: Chen
authors.forename: Craig W
authors.initials: CW
authors.lastname: Stevens
mesh_terms: D000818:Animals; D001260:Ataxia Telangiectasia / Q000235:genetics; D064007:Ataxia Telangiectasia Mutated Proteins; D016466:CHO Cells; D018797:Cell Cycle Proteins; D006224:Cricetinae; D051747:DNA-Activated Protein Kinase; D004268:DNA-Binding Proteins; D006801:Humans; D009687:Nuclear Proteins; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism* / Q000528:radiation effects; D011994:Recombinant Proteins / Q000378:metabolism / Q000528:radiation effects; D011995:Recombination, Genetic / Q000528:radiation effects; D014162:Transfection; D025521:Tumor Suppressor Proteins
chemical_list: D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D011994:Recombinant Proteins; D025521:Tumor Suppressor Proteins; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; D051747:DNA-Activated Protein Kinase; C497263:PRKDC protein, human; D017346:Protein Serine-Threonine Kinases