TY - JOUR
T1 - Evaluation of a Tetrazolium-based Semiautomated Colorimetric Assay
T2 - Assessment of Radiosensitivity
AU - Carmichael, J.
AU - DeGraff, W. G.
AU - Gazdar, A. F.
AU - Minna, J. D.
AU - Mitchell, J. B.
PY - 1987/2
Y1 - 1987/2
N2 - Radiation survival curves were generated for V79 Chinese hamster and two human lung cancer cell lines (NCI-H460 and NCI-H249) with doubling times of 10, 20, and 85 h, respectively, using a standard clonogenic assay, a dye exclusion assay, and a semiautomated colorimetric assay utilizing a tetrazolium salt, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyiformazan bromide. Comparable results for D0and extrapolation number (n) were observed for all assays in the lines with doubling times of 10 and 20 h. In these instances the tumor cell lines had undergone seven or more doublings after radiation. For the tumor line (H249) with an 80-h doubling time the D 0s were comparable between the assays while the extrapolation number was increased in the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenylformazan bromide assay, a result probably related to the lower number of doublings (<4) after radiation. We then tested the ability of the assays to detect radiation protection and sensitization using known agents. We found that cysteamine treatment resulted in radioprotection (by a factor of 8 at 8 Gy) while 5-bromo-2-deoxyuridine incorporation caused enhancement of radiation sensitivity in all three assays. We conclude that, while optimal conditions for each cell line (cell number plated and doubling time) must be established, using characterized tumor cell lines, the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenylformazan bromide assay could be automated and thus be of great value in screening large numbers of potential radiosensitizers or protectors.
AB - Radiation survival curves were generated for V79 Chinese hamster and two human lung cancer cell lines (NCI-H460 and NCI-H249) with doubling times of 10, 20, and 85 h, respectively, using a standard clonogenic assay, a dye exclusion assay, and a semiautomated colorimetric assay utilizing a tetrazolium salt, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyiformazan bromide. Comparable results for D0and extrapolation number (n) were observed for all assays in the lines with doubling times of 10 and 20 h. In these instances the tumor cell lines had undergone seven or more doublings after radiation. For the tumor line (H249) with an 80-h doubling time the D 0s were comparable between the assays while the extrapolation number was increased in the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenylformazan bromide assay, a result probably related to the lower number of doublings (<4) after radiation. We then tested the ability of the assays to detect radiation protection and sensitization using known agents. We found that cysteamine treatment resulted in radioprotection (by a factor of 8 at 8 Gy) while 5-bromo-2-deoxyuridine incorporation caused enhancement of radiation sensitivity in all three assays. We conclude that, while optimal conditions for each cell line (cell number plated and doubling time) must be established, using characterized tumor cell lines, the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenylformazan bromide assay could be automated and thus be of great value in screening large numbers of potential radiosensitizers or protectors.
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M3 - Article
C2 - 3802101
AN - SCOPUS:0023158779
VL - 47
SP - 943
EP - 946
JO - Cancer Research
JF - Cancer Research
SN - 0008-5472
IS - 4
ER -