An epithelial cell adhesion molecule (EpCAM) was selectively expressed in human colorectal carcinoma. Treatment with plant-derived anti-EpCAM mAb (mAb(P) CO17-1A) and RAW264.7 cells inhibited cell growth in the human colorectal cancer cell line SW620. In SW620 treated with mAb(P) CO17-1A and RAW264.7 cells, expression of p53 and p21 increased, whereas the expression of G1 phase-related proteins, cyclin D1, CDK4, cyclin E, and CDK2, decreased, similar to mammalian-derived mAb (mAb(M)) CO17-1A. Similar to mAb(M) CO17-1A, treatment with mAb(P) CO17-1A and RAW264.7 cell decreased the expression of anti-apoptotic protein, Bcl-2, but the expression of pro-apoptotic proteins Bax, TNF-alpha, caspase-3, caspase-6, caspase-8 and caspase-9, increased. Cells treated with mAb(P) CO17-1A and RAW264.7 cells expressed metastasis-related gangliosides, GM1 and GD1a, similar to mAb(M) CO17-1A. These results suggest that mAb(P) CO17-1A is as effective on anti-cancer activity as mAb(M) CO17-1A.