DNA-dependent protein kinase content and activity in lung carcinoma cell lines: correlation with intrinsic radiosensitivity.
Intrinsic radiosensitivity and rejoining of radiation-induced DNA double-strand breaks (DNA-dsb) were analysed in five lung carcinoma cell lines: U-1285, U-1906, H-69, H-82 and U-1810. RS correlated with both the initial phase of DNA-dsb rejoining, at 15 min (r2 = 0.818) and the late phase, at 120 min postirradiation (r2 = 0.774), the most sensitive cell line (U-1285) showing least dsb rejoining and the most resistant (U-1810) showing most dsb rejoining of all five cell lines studied. As DNA-PK has been recognised as an important molecular component involved in DNA-dsb repair, we analysed content and activity of this kinase. We found that DNA-PK content and activity correlated with RS (r2 = 0.941 and r2 = 0.944, respectively). The lowest DNA-dependent content/activity was found in the most radiosensitive cells, U-1285 and H-69, whilst the highest content/activity was found in the most radioresistant cells U-1810. These results suggest a correlation between RS and DNA-PK content/activity in lung carcinoma cell lines.
Sirzén
F
F
Department of Oncology, Radiumhemmet, Karolinska Institute, Stockholm, Sweden.
Nilsson
A
A
Zhivotovsky
B
B
Lewensohn
R
R
D015153:Blotting, Western; D018288:Carcinoma, Small Cell / Q000201:enzymology* / Q000235:genetics; D004260:DNA Repair; D004273:DNA, Neoplasm / Q000378:metabolism / Q000528:radiation effects*; D051747:DNA-Activated Protein Kinase; D004268:DNA-Binding Proteins; D006801:Humans; D008175:Lung Neoplasms / Q000201:enzymology* / Q000235:genetics; D009687:Nuclear Proteins; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011836:Radiation Tolerance; D014407:Tumor Cells, Cultured / Q000528:radiation effects
D004273:DNA, Neoplasm; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D051747:DNA-Activated Protein Kinase; C497263:PRKDC protein, human; D017346:Protein Serine-Threonine Kinases