Potential Role of CD68 in Breast Cancer Bone Metastasis

Abstract

Abstract : Bone is a common site of metastasis in breast cancer patients, leading to serious clinical consequences and a poor prognosis. The molecular mechanisms regulating this preferential metastasis of breast cancer to bone have not yet been fully elucidated. Using a Phage Display-based approach by biopanning with bone slices, our lab identified macrosialin as a potential mediator of osteoclast adhesion to bone. We hypothesized that CD68 mediates attachment of breast cancer cells onto bone matrix, subsequently regulating bone metastasis. My work shows that expression of CD68 is higher in bone metastatic cell lines of breast carcinoma and that this correlates with the ability to adhere to the bone. However, assays failed to reveal a direct role of CD68 in breast cancer adhesion to bone. Preliminary work shows a potential role of CD68 as a viability factor for breast cancer, specifically with chemoresistance activity. Future studies are needed to further characterize CD68 s exact role in breast cancer, which may lead to potential therapeutic strategies. The use of CD68 as a macrophage marker in breast cancer tumors needs to be reevaluated as well, because we have shown that the actual breast cancer cells can express CD68.