Characterization of the Chemotherapy-treated PyMT Matrisome

Cytotoxic chemotherapy is used to treat many thousands of patients across many cancer types annually. Recent studies have demonstrated that chemotherapy causes systemic response that can be exploited to promote cancer cell survival and dissemination, termed “chemotherapy-induced metastasis. However, there have been no studies investigating how chemotherapy alters the extracellular matrix of breast tumors, or if those changes might help to support metastatic dissemination. Here, we report the first characterization of the chemotherapy-treated breast cancer matrisome using the MMTV-PyMT transgenic mouse model of breast cancer. We identify distinct changes induced by different cytotoxic chemotherapies. In particular, we identify collagen IV as significantly associated with taxane-based chemotherapy treatment. Biological validation confirmed collagen IV as chemotherapy-associated and identified collagen IV-driven Src and FAK signaling as important mediators of invasion in the post-chemotherapy tumor microenvironment.