CD44 is an adhesion molecule that accelerates migration and invasion of cancer cells and has been recognized as a marker of cancer stem cells in breast cancer. CD44 has two distinct isoforms, standard (CD44s) and variant (C044v), which are expressed in mesenchymal and epithelial cells, respectively. We previously showed using mouse 4T1 breast cancer cells that CD44v plays a role in protecting cancer cells from the stressors of reactive oxygen species (ROS). We further showed that sulfasalazine,which targets CD44v, deteriorated this anti-ROS mechanism and inhibited lung metastasis of 4T1 cells. However, we do not know whether this same scenario is seen in human breast cancer.
Triple-negative breast cancer (TNBC) lacks the expression of estrogen receptor, progesterone receptor, and HER2 and thus cannot be treated with anti-estrogens and anti-HER2 therapy. Inflammatory breast cancer (IBC) accounts for up to 2-5% of breast cancer cases, but up to 10% of breast cancer-related deaths.