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- Palm, Stig, 1964, et al.
(författare)
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Cell growth kinetics of the human cell line Colo-205 irradiated with photons and astatine-211 alpha-particles
- 2000
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Ingår i: Anticancer Res. - 0250-7005. ; 20:3A, s. 1807-12
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Tidskriftsartikel (refereegranskat)abstract
- Cell growth kinetics following Astatine-211 (211At, alpha-particle emitter) and photon irradiation were studied for the human colorectal cell line Colo-205. A growth assay using 96-well plates was chosen. The growth kinetics could be simulated by assuming certain fractions of cells with various proliferative capacities, i.e. from none up to 5 cell doublings, in addition to the defined survivors with remaining unlimited clonogenic capacity. No significant difference in cell growth characteristics was seen between 211At and photon irradiation. The cell doubling time, as calculated from the increment in optical density, was compared with the results from BrdU experiments in the early phases of growth (Tpot = 18.5 +/- 0.6 h for LDR (low dose rate) photon irradiated and 20.3 +/- 0.8 hours for sham-irradiated cells 40-45 hours post-irradiation) confirming the transient accelerated growth of irradiated cells. No statistically significant difference in growth was found between LDR, MDR (medium dose rate) and HDR (high dose rate) photon irradiation.
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| 3. |
- Palm, Stig, 1964, et al.
(författare)
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In vitro effects of free 211At,211At-albumin and 211At-monoclonal antibody compared to external photon irradiation on two human cancer cell lines
- 2000
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Ingår i: Anticancer Res. - 0250-7005. ; 20:2A, s. 1005-12
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The aim of this study was to perform various 211At irradiations of importance for the evaluation of 211At-radioimmunotherapy, and compare the effect with that of low linear energy transfer (LET) radiation. MATERIALS AND METHODS: All irradiations were performed on low-concentration single-cell suspensions. Growth assays using 96-well plates were used to estimate apparent cell survival. Centrifuge tube filters were used to estimate the cell uptake and binding of 211At. RESULTS: A relative biological effect (RBE) of 12 +/- 2 (Colo-205) and 5.3 +/- 0.7 (OVCAR-3) was found from 211At-albumin irradiations. There was a 174 +/- 28 times higher free 211At concentration in the cell fraction than in the surrounding medium. For 211At-MAb, an 8,000-30,000 times higher concentration in the cell fraction was achieved, compared to the medium. Corrected for the uptake, an average of 31 +/- 2 ([211At]-astatine) or 26 +/- 5 ([211At]-MAb) decays per cell were required for 37% survival of Colo-205 cells. An average of 19 +/- 3 decays ([211At]-astatine) were required per OVCAR-3 cell. CONCLUSIONS: Cell uptake and binding of 211At was unexpectedly high, possibly favouring its therapeutic use. The binding is probably to the cell surface. The RBE is 5.3 +/- 0.7 for OVCAR-3 and 12 +/- 2 for Colo-205 cells.
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- Palm, Stig, 1964, et al.
(författare)
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Single-cell irradiation from [211At] astatine-labeled C215 monoclonal antibody: improved estimates of radiosensitivity from measurements on cellular uptake and retention
- 2003
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Ingår i: Anticancer Res. - 0250-7005. ; 23:2B, s. 1219-21
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Tidskriftsartikel (refereegranskat)abstract
- New data on the biological effect of 211At-C215 monoclonal antibody in a slowly rotating, widely dispersed single-cell suspension of the human cancer cell line Colo-205 is presented. Cell growth curves of each experiment were used to calculate an apparent cell survival after irradiation. Uptake measurements provided the data needed to calculate the average number of 211At decays per cell in the cell suspension. The results from each experiment were then fit to a mono-exponential function. From the exponential fit, an average of 35 +/- 2 (SD) astatine-211 decays per cell are required for 37% apparent cell survival (D0).
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