Establishing hematopoietic stem cell gene therapy for breast cancer brain metastases using intratumoral myeloid cell-specific gene promoters

The goal was to identify genes that are differentially expressed between the bone marrow-derived CD11b+ myeloid cells infiltrating intracranial tumors and the peripheral myeloid cells (e.g. infiltrating the spleen and bone marrow). Murine breast cancer cells (EO771 or PyMT, respectively) were injected intracranially into C57Bl6 mice with chimeric green fluorescent protein (GFP)-tagged bone marrow. Approximately 2 weeks later, the intracranial tumors, the spleens and the bone marrow were harvested, the GFP+CD11b+ cells were isolated by FACS and processed for RNA isolation.