Disclosed is an isolated monoclonal antibody, which antibody specifically binds to an epitope on the extracellular domain of a human CD43, human CEA expressed by human colorectal cancer cell, a human pancreatic cancer cell, a human gastric cancer cell, a human ovarian cancer cell, a human cancer esophageal cell, or a human endometrial cancer cell but does not specifically bind to a CD43 expressed on the cell surface of human peripheral T cells or Jurkat cells, and is capable of inducing apoptosis of the cancer cell after binding to the epitope on cell surface of the cancer cell in vitro in the absence of cytotoxin conjugation and immune effector function, wherein epitope comprises a carbohydrate and the binding of the antibody to the epitope is inhibited by oligosaccharides Lea, Lea-lactose, and Lacto-N-difucohexose II (LNDFH II). Also disclosed is the use of the antibody in the manufacture of a medicament for the treatment of a colorectal cancer, a pancreatic cancer, a gastric cancer, an ovarian cancer, an esophageal cancer, or an endometrial cancer.
