Relationship between ganglioside expression and anti-cancer effects of a plant-derived antibody in breast cancer cells

Production of therapeutic monoclonal antibodies (mAbs) using a plant platform has been considered an alternative to the mammalian cell-based production system. A plant-derived mAb CO17-1AK (mAbP COK) can specifically bind to various types of cancer cell lines. The target protein of mAbP COK is the epithelial cell adhesion molecule (EpCAM) highly expressed in human epithelial cancer cells, including breast and colorectal cancer cells. It has been hypothesized that its overexpression supports tumor growth and metastasis. A ganglioside is extended well beyond the surfaces of the various cell membranes and has roles in cell growth, inflammation, differentiation, and carcinogenesis. However, the regulation of EpCAM gene expression in breast cancers and the role of gangliosides in oncogenesis are unclear. Here, the purpose of this study was to determine the effects of mAbP COK on human breast cancer cell proliferation, apoptosis, and ganglioside expression patterns. Our results show that treatment with mAbP COK suppressed the growth of breast cancer cells and induced apoptotic cell death. It also upregulated the expression of metastasis-related gangliosides in breast cancer cells. Thus, treatment with mAbP COK may have chemo-preventive therapeutic effects against human breast cancer.