title: The association of DNA-dependent protein kinase activity of peripheral blood lymphocytes with prognosis of cancer.
abstract: BACKGROUND
  Repair of various types of DNA damages is critical for genomic stability. DNA-dependent protein kinase (DNA-PK) has an important role in DNA double-strand break repair. We examined whether there may be a correlation between DNA-PK activity in peripheral blood lymphocytes (PBLs) and survival percentages in various cancer patients. We also investigated the changes of DNA-PK activity in PBLs after radiotherapy.
  
  
  METHODS
  A total of 167 of untreated cancer patients participated in this study. Peripheral blood was collected, separated, and centrifuged. DNA-PK activity was measured by DNA-pull-down assay. Chromosomal aberrations were examined by cytogenetic methods.
  
  
  RESULTS
  DNA-PK activity of PBLs in advanced cancer patients was significantly lower than that in early stage. The patients with lower DNA-PK activity in PBLs tended to have the lower disease-specific survivals and distant metastasis-free survivals than those with higher DNA-PK activity in advanced stages. There was also a tendency of inverse correlation between DNA-PK activity and excess fragments. The DNA-PK activity of PBLs in most patients decreased in response to radiation as the equivalent whole-body dose increased.
  
  
  CONCLUSIONS
  Cancer patients in advanced stage, with lower DNA-PK activity of PBLs might have higher distant metastasis and exhibit poorer prognosis. Therefore, DNA-PK activity in PBLs could be used as a marker to predict the chromosomal instability and poorer prognosis.
authors.affiliation: Department of Radiology, Sapporo Medical University, School of Medicine, Hokkaido, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Someya
authors.forename: K-i
authors.initials: KI
authors.lastname: Sakata
authors.forename: Y
authors.initials: Y
authors.lastname: Matsumoto
authors.forename: R P
authors.initials: RP
authors.lastname: Kamdar
authors.forename: M
authors.initials: M
authors.lastname: Kai
authors.forename: M
authors.initials: M
authors.lastname: Toyota
authors.forename: M
authors.initials: M
authors.lastname: Hareyama
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002869:Chromosome Aberrations; D051747:DNA-Activated Protein Kinase / Q000378:metabolism*; D005260:Female; D006801:Humans; D008214:Lymphocytes / Q000201:enzymology* / Q000528:radiation effects; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009369:Neoplasms / Q000097:blood / Q000235:genetics / Q000401:mortality* / Q000532:radiotherapy; D009687:Nuclear Proteins / Q000378:metabolism*; D011379:Prognosis
chemical_list: D009687:Nuclear Proteins; D051747:DNA-Activated Protein Kinase; C497263:PRKDC protein, human