Figure 4

GNP-mediated DTBR significantly decreased HNCC proliferation in vivo. Groups of 15–20 zebrafish larvae were used for each time point and treatment group, 50–100 cells were injected into the yolk sac of each fish, and the number of fluorescent cells was quantified ex vivo. Xenografted cells were quantified at baseline (0 days post radiation (dpr)) and 3 dpr after treatment with 8 Gy from the STB or DTB. Results are represented as fold change of the unirradiated control cells (No RT). (a) With GNP-DTBR, Detroit-562 and HSC-3 xenografted cells demonstrate increased cell death compared to NoNP-DTBR (p = 0.005 and p = 0.015, respectively), and FaDu cells exhibit increased cell death compared to GNP-STBR (p = 0.022). There were no significant differences in Panc1 cancer cell proliferation between treatment groups in vivo. (b) Representative images of fluorescently labelled HSC-3 HNCCs injected into the yolk sac of casper larvae, scale bars are 200 µM. Results are presented as fold change means ± standard error of the mean, p* < 0.05, p** < 0.01, p*** < 0.001 for significant decreases in in vivo cell proliferation. Significance between groups was tested using one-way analysis of variance (ANOVA) with a Tukey multiple comparisons test (n = 3; 20 larvae per group/replicate). GNP gold nanoparticles, NoNP no nanoparticles, HNCC head and neck cancer cells, STB(R) standard target beam (radiation), DTB(R) diamond target beam (radiation).