title: Comprehensive profiling of radiosensitive human cell lines with DNA damage response assays identifies the neutral comet assay as a potential surrogate for clonogenic survival.
abstract: In an effort to explore the possible causes of human radiosensitivity and identify more rapid assays for cellular radiosensitivity, we interrogated a set of assays that evaluate cellular functions involved in recognition and repair of DNA double-strand breaks: (1) neutral comet assay, (2) radiation-induced γ-H2AX focus formation, (3) the temporal kinetics of structural maintenance of chromosomes 1 phosphorylation, (4) intra-S-phase checkpoint integrity, and (5) mitochondrial respiration. We characterized a unique panel of 19 "radiosensitive" human lymphoblastoid cell lines from individuals with undiagnosed diseases suggestive of a DNA repair disorder. Radiosensitivity was defined by reduced cellular survival using a clonogenic survival assay. Each assay identified cell lines with defects in DNA damage response functions. The highest concordance rate observed, 89% (17/19), was between an abnormal neutral comet assay and reduced survival by the colony survival assay. Our data also suggested that the neutral comet assay would be a more rapid surrogate for analyzing DNA repair/processing disorders.
authors.affiliation: UCLA School of Medicine, Department of Pathology and Laboratory Medicine, Los Angeles, California 90095, USA. snahas@mednet.ucla.edu
authors.forename: Shareef A
authors.initials: SA
authors.lastname: Nahas
authors.forename: Robert
authors.initials: R
authors.lastname: Davies
authors.forename: Francesca
authors.initials: F
authors.lastname: Fike
authors.forename: Kotoka
authors.initials: K
authors.lastname: Nakamura
authors.forename: Liutao
authors.initials: L
authors.lastname: Du
authors.forename: Refik
authors.initials: R
authors.lastname: Kayali
authors.forename: Nathan T
authors.initials: NT
authors.lastname: Martin
authors.forename: Patrick
authors.initials: P
authors.lastname: Concannon
authors.forename: Richard A
authors.initials: RA
authors.lastname: Gatti
mesh_terms: D001681:Biological Assay / Q000379:methods*; D002460:Cell Line / Q000502:physiology* / Q000528:radiation effects*; D003114:Colony-Forming Units Assay / Q000379:methods*; D020552:Comet Assay / Q000379:methods*; D004249:DNA Damage; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D011829:Radiation Dosage; D011836:Radiation Tolerance / Q000502:physiology*