Abstract
We investigated the multiformity of the sugar chain (s) of carcinoembryonic antigen (CEA) in various subjects by using serial lectin affinity chromatographies. This technique revealed a possible structure of sugar chain (s) of tumor-associated CEA. The sugar chain (s) of serum CEA from normal adult and the patients with benign disease had biantennary complex type without the fucose residue and hybrid type without the internal fucose residue. The sugar chain (s) of serum CEA from cancer patients without distant metastasis had biantennary complex type and hybrid type without the internal fucose residue. But, besides those of sugar chain (s), the increase of multiantennary complex type and high mannose type sugar chain (s) were observed in the sugar chain (s) of CEA in the patients with distant metastasis. These results suggested that the tumor-associated CEA may relate to the fucoslylation of the sugar chain (s) and/or the increasing of sugar chain (s) with bisecting GIcNAc, as in a case of α-fetoprotein. Thus, the measurement of CEA subfractions may be useful for diagnosis of a patient with distant metastasis of cancer.
