Extended Data Fig. 1: Radiation exposure in healthy lung tissue enhances metastasis.
a, Representative H&E images of metastatic lungs from control (UT) and irradiated BALB/c mice orthotopically injected with 4T1 breast cancer cells to generate a primary tumour. The metastatic area is depicted with a dashed line (n = 4 mice per group, 2 independent experiments). Scale bar, 250 μm. b,c, FACS quantification of GFP+ tumour cells in the metastatic lung (b) and primary tumour volume (c) from control and irradiated mice (n = 4 mice per group, one experiment). d,e, Representative H&E images (d) and FACS quantification of GFP+ tumour cells (e) from metastatic lungs from control (UT) or irradiated FVB mice intravenously injected with GFP+ MMTV-PyMT primary mammary tumour cells at day 7 (n = 5 per group, one experiment). Scale bar, 100 μm. f, Table and representative immunostaining of human-specific Lamin A/C to detect human lung cancer cells growing in BALB/c Nude mice (n = 4 mice per group for each cell line tested). Mice were intravenously injected with H460 or A549 human NSCLC cells 7 days following targeted lung irradiation (or sham-irradiation for control mice) and lungs harvested 3 weeks later. The table depicts the number of mice in which h-Lamin A/C+ cancer cells were present in the lungs. No foci were detected in control mice from either experimental group. The representative images show an example of a Lamin A/C+ metastatic foci within an irradiated lung, for each cell line. The H460 metastatic lesion (left) is indicated with the arrow. Scale bar, 250 μm. g, Violin plot showing the number of metastatic foci in the non-irradiated left lung lobe from mice that received image-guided targeted radiation to the right lung (n = 5 for 8 Gy mice; n = 7 for 12 Gy mice), compared with control mice (n = 6). The violin plot displays the median, 25th and 75th percentiles as well as the density of data points. Dots represent individual mice. All data represented as mean ± s.e.m. Statistical analysis by non-parametric two-tailed Mann-Whitney test for (b), (c) and (e) and a one-way ANOVA with multiple comparisons for (g). UT, untreated. IR, irradiated. Gating strategies for FACS analysis provided in Extended Data Fig. 2. Histology quantification process outlined in Supplementary File 1.
