Fig. 4

Microglia Tmem119 is downregulated in breast cancer brain metastasis. (A) Breast cancer brain metastases were established by intracardiac injection of E0771-BrM cells. Control tissue (BrM-) and tumor samples (BrM+) were collected based on ex vivo bioluminescence imaging. (B) Representative gating strategy used to identify microglia and infiltrating CD45^high myeloid cells in BrM + samples. (C) Representative flow cytometry histogram of Tmem119-PE/Cy7 and isotype controls. (D) Quantification of Tmem119-PE/Cy7 MFI in the different cell populations. P values are the result of one-way ANOVA with Tukey HSD. Data are presented as mean ± S.D. N = 7 mice. (E) RT-qPCR analysis comparing relative quantities of Tmem119 in microglia sorted from naïve mice brains and BrM + samples. P values are the results of unpaired two-tailed T-test. Data are presented as mean ± S.D. N = 3 naïve mice and 8 BrM + samples. (F) Brain metastases were established in Tmem119-eGFP mice, and paired BrM- samples were collected from anatomically matched brain regions on the non-tumor-bearing hemisphere of the same animal. (G) Representative flow cytometry histogram of Tmem119-eGFP signal from BrM- MG, BrM + MG, and BrM + CD45^high myeloid cells. (H) Quantification of Tmem119-eGFP MFI in the different cell populations. P values are the results of paired two-tailed T-tests. N = 4 mice. (I) Percentage of GFP^low populations in microglia and CD45^high myeloid cells. P values are the results of paired two-tailed T-tests. N = 4 mice