Lack of a correlation between radiosensitivity and DNA double-strand break induction or rejoining in six human tumor cell lines.
The neutral filter elution method and the neutral comet assay have been used to analyze radiation-induced DNA damage and repair in 6 human tumor cell lines: HT-144 melanoma; DU-145 prostate carcinoma; U-87 glioma; WiDr and HT-29 colon adenocarcinomas; and SiHa cervical carcinoma. In spite of large differences in intrinsic radiosensitivity measured using a clonogenic assay, double-strand break induction, rejoining rate, and amount of residual DNA damage 4 h after irradiation were similar among these cell lines when measured using the neutral comet assay. Differences in initial numbers of double-strand breaks were observed using the neutral filter elution method; however, there was no correlation with radiosensitivity, nor did the rejoining rate or amount of residual DNA damage measured using filter elution correlate with radiation sensitivity. We conclude that neither double-strand break assay is able to reliably rank cells according to clonogenic survival following irradiation.
British Columbia Cancer Research Centre, Vancouver, Canada.
P L
PL
Olive
J P
JP
Banáth
H S
HS
MacPhail
D002470:Cell Survival / Q000528:radiation effects; D004249:DNA Damage; D004260:DNA Repair; D005260:Female; D006801:Humans; D008297:Male; D009369:Neoplasms / Q000235:genetics / Q000473:pathology / Q000532:radiotherapy*; D011836:Radiation Tolerance; D014407:Tumor Cells, Cultured