Expression data from breast cancer bone metastasis [EO771]. Mus musculus

The goal of this study was to evaluate genes that are differentially expressed in the bone stroma when breast cancer metastasis are present. We focused our attention on bone stroma cells to understand how the dissemination and growth of tumor cells can impact on the bone environment. Moreover, we aimed to identify potential targets to inhibit the cross talk between cancer cells and tumor microenvironment in bone metastasis. EO771 breast cancer cell line were engineered to express luciferase and GFP, and injected in C57BL/6 mice by the intracardiac route to obtain bone metastasis. Tumor growth was monitored in-vivo by bioluminescence for 2 weeks. Endothelial cells and osteoblasts were isolated from the long bones of tumor-bearing and tumor-free mice to identify genes differentially expressed. Overall design: Bone marrow single cell suspensions from tumor-free or tumor-bearing mice (n=6-10 samples) were prepared by grinding bones in a mortar followed by enzymatic digestion of the bone powder for 1 hour at 37°C with 1 mg/ml collagenase, 1 mg/ml dispase and 50KU/ml DNAse. Stroma cells and hematopoietic fractions were enriched by discontinuous percoll density gradient separation (1.065 g/L and 1.115 g/L). Remaining red blood cells were lysed and the single cell population was stained to isolate two different stroma cells by FACS: osteoblasts (OBctr) (OBtum), were identified as GFP-TR119-CD45-SCA1-CD31-CD51+, and endothelial cells (ECctr) (ECtum) were identified as GFP-TR119-CD45-SCA1+CD31+.