title: A flow cytometry assay that measures cellular sensitivity to DNA-damaging agents, customized for clinical routine laboratories.
abstract: OBJECTIVE
  The clonogenic assay examines cell sensitivity to toxic agents and has been shown to correlate with normal tissue sensitivity to radiotherapy in cancer patients. The clonogenic assay is not clinically applicable due to its intra-individual variability and the time frame of the protocol. We aimed to develop a clinically applicable assay that correlated with the clonogenic assay.
  
  
  METHODS
  We have developed a faster and less labor-intensive cell division assay (CD assay) using flow cytometry and incorporation of a fluorescent thymidine analogue. The CD assay was calibrated to the clonogenic assay and optimized for peripheral blood lymphocytes.
  
  
  RESULTS
  Following ionizing radiation of primary human skin fibroblasts, the four-day CD assay gave similar results as the 14-day clonogenic survival assay. In lymphocytes isolated from patient blood samples, the CD assay was able to detect increased radiosensitivity in ataxia telangiectasia patients and increased radiosensitivity after in vitro treatment with DNA-PK and ATM inhibitors. The CD assay found a variation in the intrinsic radiosensitivity of lymphocytes isolated from healthy control samples. The CD assay was able to measure the anti-proliferation effect of different chemotherapeutic drugs in lymphocytes.
  
  
  CONCLUSIONS
  Our results indicate that the CD assay is a fast and reliable method to measure the anti-proliferation effect of DNA-damaging agents with a potential to find the most sensitive patients in the work-up before cancer treatment.
authors.affiliation: Department of Clinical Chemistry and Transfusion Medicine, Institute of Biomedicine, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
authors.forename: Sherin T
authors.initials: ST
authors.lastname: Mathew
authors.affiliation: Department of Clinical Chemistry and Transfusion Medicine, Institute of Biomedicine, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
authors.forename: Pegah
authors.initials: P
authors.lastname: Johansson
authors.affiliation: Department of Clinical Chemistry and Transfusion Medicine, Institute of Biomedicine, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
authors.forename: Yue
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Department of Pediatrics, Institute of Clinical Sciences, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Fasth
authors.affiliation: Department of Pediatrics, Hospital of Halland, Halmstad, Sweden.
authors.forename: Torben
authors.initials: T
authors.lastname: Ek
authors.affiliation: Department of Clinical Chemistry and Transfusion Medicine, Institute of Biomedicine, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden. Electronic address: ola.hammarsten@clinchem.gu.se.
authors.forename: Ola
authors.initials: O
authors.lastname: Hammarsten
mesh_terms: D001260:Ataxia Telangiectasia / Q000188:drug therapy / Q000473:pathology* / Q000532:radiotherapy; D064007:Ataxia Telangiectasia Mutated Proteins / Q000037:antagonists & inhibitors; D049109:Cell Proliferation / Q000187:drug effects / Q000528:radiation effects; D002478:Cells, Cultured; D002867:Chromones / Q000494:pharmacology; D019411:Clinical Laboratory Techniques / Q000592:standards*; D003114:Colony-Forming Units Assay; D004249:DNA Damage / Q000187:drug effects / Q000528:radiation effects; D051747:DNA-Activated Protein Kinase / Q000037:antagonists & inhibitors; D005199:Fanconi Anemia / Q000188:drug therapy / Q000473:pathology* / Q000532:radiotherapy; D005347:Fibroblasts / Q000187:drug effects / Q000473:pathology* / Q000528:radiation effects; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects / Q000528:radiation effects; D009025:Morpholines / Q000494:pharmacology; D011753:Pyrones / Q000494:pharmacology; D011836:Radiation Tolerance; D011839:Radiation, Ionizing; D012867:Skin / Q000187:drug effects / Q000473:pathology* / Q000528:radiation effects
chemical_list: C495818:2-morpholin-4-yl-6-thianthren-1-yl-pyran-4-one; C499693:8-dibenzothiophen-4-yl-2-morpholin-4-yl-chromen-4-one; D002867:Chromones; D009025:Morpholines; D011753:Pyrones; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; D051747:DNA-Activated Protein Kinase
keywords: Cell division; Clonogenic assay; DNA-damaging agents; Drug sensitivity; Intrinsic radiation sensitivity