In this issue of Cancer Cell, Cassetta et al. present a detailed analysis of the transcriptional profile imprinted on monocytes and macrophages by human breast and endometrial cancers, proposing SIGLEC1 and CCL8 as novel biomarkers in tumor-associated macrophages for breast cancer patient stratification and prognosis.
In order to better understand how tumors engage distal sites and activate a pro-inflammatory response we utilized syngeneic breast cancers as a model and showed that soluble factors from the neoplastic epithelium activate the expression of the monocyte chemoattractive protein (MCP) chemokines of the mouse 11C cluster that include Ccl1, Ccl2, Ccl7, Ccl8, Ccl11 and Ccl12.
These findings exemplify how gradients of chemoattractive factors such as CCL8, drive metastasis and suggest that interference with their operation may provide means for breast cancer management.