The measured SF2 and SF5 of 27 canine tumor cell lines.

<p>27 cell lines are ranked based on SF2 (A) and SF5 (B). Red circle: radiosensitive group, blue circle: radioresistant group. (C, D) Comparison between the mean values of two groups based on the SF2 (C) or SF5 (D). Error bars indicate standard deviation. * p<0.001 versus sensitive and resistant group (unpaired t-test).</p

Characteristics and radiation survival of 27 cell lines used in this study.

<p>Characteristics and radiation survival of 27 cell lines used in this study.</p

Phosphorylated-H2AX foci in G1 irradiated cells of radioresistant and radiosensitive groups of canine tumor cell lines.

<p>Cells were synchronized in G1 using isoleucine deficient media and then irradiated with 1 Gy of gamma-rays. Following 30 min or 6 hr incubation time, cells were stained with γ-H2AX. (A) Examples of γ-H2AX foci (green) in nuclear DAPI (blue) staining in control, 1Gy followed by 30 min incubation and 1 Gy followed by 6 hr incubation in EdU negative cells. (B) Quantitative analysis of gamma-H2AX foci per cell. The pooled data from three independent experiments scoring 50 cells in each experiment are shown. The bar indicates mean. Statistical significances are shown for only control versus 6 h after 1 Gy (nonparametric Kruskal-Wallis test).</p

Plots of the cellular characteristics as a function of the SF2 values in each cell line.

<p>Each dot represents a cell line. The correlations were assessed using the Pearson test. The lines were fitted by a least-squares method.</p

Radiation-induced apoptosis in the radioresistant and radiosensitive canine cancer cell lines.

<p>(A) Caspase 3/7 activity measured by luminomator at 16 hours after irradiation. (B) Annexin V and 7AAD staining measured by flow cytometer at 24 hours after irradiation. (C) TUNEL staining and (D) DAPI staining measured by fluorescent microscope. Cells irradiated with 0 Gy and 5 Gy of gamma-rays. *, p<0.05 versus 0 Gy and 5 Gy for each cell line (unpaired t-test).</p

SCE induction from radioactive solutions.

<p>Radioavtivities (CPM) are at the time of solution transferred. Pooled SCE data induced by water and PBS activated by different hadron radiation types were plotted. Data were fit with semi-log line (R square = 0.722). Observed SCE = 0.017 x log(CPM) + background SCE.</p

Radioactivation after 100 Gy of proton exposure to PBS measured by NaI scintillation detector.

<p>(A) Energy spectrum of NaI detector. A clear peak of annihilation gamma-rays at 0.511 MeV is shown. (B) Time course change of measured count rates of 511 keV gamma-rays. Data was fitted with three-phase exponential decay model with half-lives of 2 min (93%), 10 min (3.5%), and 20 min (4.5%).</p

Radioactivation of the solution after different types of hadron radiation exposure.

<p>Radioactivities were measured as counts per minute (CPM) by GM counter. <b>(</b>A) Comparison of activation of H₂O and PBS. (B) Initial radioactivation per exposed doses. The * indicates that more than 10 Gy of proton exposure induced higher than GM detector’s upper limit. (C-E) Time course of radioactivities after (C) proton, (D) carbon-ion, and (E) iron-ion exposures. Lines were fitted with one-phase exponential decay curves with half-lives of approximately 20 minutes. Experiments were carried out at least three times, and error bars indicate SEM.</p

SCE induction from gamma-ray exposed solution.

<p>No significant difference was observed in the mean SCE frequencies among the samples by one-way ANOVA (p = 0.799). Experiments were carried out at least three times and error bars indicate SEM.</p

Telomere abnormalities.

<p>Representative FISH images of the eight canine OSA cell lines’ metaphase chromosomes hybridized with probes against telomeres. Blue represents DNA staining by DAPI and red represents a telomere signal by Cy3. Note the abnormal telomere signals in the magnification box; interstitial telomere signals (A and F), more than one telomere signal in centromere regions (B, D and E), and one or no telomere signal (C) is observed. Note that at the end of chromosomes, there is no telomere signal present (B and E).</p