Figure 1.

GATA3 suppresses spontaneous and experimental breast cancer metastases to the lungs. (a) GATA3 expression levels from basal A, basal B and luminal breast cancer cell lines. Microarray data set is adapted from ref. 25. ** one-way analysis of variance P < 0.001. (b) Relative Gata3 levels in 4T1 cells ± Gata3 measured by qPCR (n = 8 independently obtained biological samples, **P < 0.001). (c–g) BALB/c mice were injected with 4T1 cells ± Gata3 into the inguinal mammary fat pad. Tumours were allowed to grow for three weeks and measured (c) and immunohistochemical staining for GATA3 in primary tumours was performed (d). The lungs were collected and examined for metastases (e). (n = 12 independent mice per group, *P < 0.01.) Representative H&E images (f) and immunohistochemical staining for GATA3 (g) in lung metastases are shown. (h,i) CD31 immunohistochemical mean intensity (h) and F4/80 immunohistochemical mean intensity (i) in primary 4T1 ± Gata3 tumours. (Values derived from n =8 independent tumours per group, and 10 random fields per tumour.) Representative images are shown below the graphs (*P < 0.05). (j) BALB/c mice were injected i.v. with 4T1 cells ± Gata3. Bioluminescence imaging was performed on day 14 post-injection and mice were euthanized immediately after imaging (n = 10 independent mice per group). (k) GATA3 immunohistochemical staining of 4T1 ± Gata3 experimental i.v. injected lung metastases. (l) BALB/c mice were co-injected i.v. 1:1 with control cells labelled with RFP (4T1-RFP) and Gata3-expressing cells labelled in GFP (4T1-Gata3–GFP). Mice were euthanized on day 12 post-injection and the percentages of RFP- and GFP-positive cells were determined by flow cytometry (n = 12 independent mice per group; **P < 0.002, paired t -test). Data are reported as mean±s.e.m. Scale bars, 200 µm (d,f,g,k) and 100 µm (h,i).