CXCL3 is a potential target for breast cancer metastasis.

Secreted proteins are an attractive minefield for cancer drug targets. An iTRAQ-based tandem mass spectrometry approach was employed to relatively quantify proteins in the secretomes of four isogenic breast cancer cell lines with increasing metastatic potential. CXCL3 was found to be upregulated in aggressive cancer cells. SiRNA and antibody neutralization studies supported a role of CXCL3 in metastatic processes. Meta-analysis of the mRNA level of CXCL3 in 1881 breast tumors supported a role of CXCL3 in clinical breast cancer. Our results support a functional role of CXCL3 in breast cancer metastasis and as a viable target for cancer therapy.