Ultrastructural localization of carcinoembryonic antigen in normal intestine and colon cancer. Abnormal distribution of cea on the surfaces of colon cancer cells

Abstract

The distribution of carcinoembryonic antigen (CEA) in normal small intestine, normal colon, and colon cancer of humans was determined immunocytochemically by the peroxidase-labeled antibody method at the light and electron microscopic levels. In the small intestine, CEA was found in protein synthetic organelles, in the mucus, on the microvilli of goblet cells, and on some microvilli of columnar cells adjacent to goblet cells. In the normal colon, CEA was found in protein synthetic organelles of the fully differentiated columnar cells and goblet cells, as well as on the microvilli of the cells. In two well-differentiated colon cancers, the normal preferential surface expression of CEA on the microvilli was maintained, but in six poorly differentiated cancers, CEA was distributed equally over the entire cell surface. We conclude that CEA is a product of goblet cells in the small intestine, columnar and goblet cells in the colon, and colonic cancer cells. CEA on the surfaces of the normal epithelial cells is expressed in a polar manner. This polarity is lacking in undifferentiated neoplastic colon cells, which suggests that failure to establish or maintain the polar expression of normal cell-surface glycoproteins is a characteristic of the neoplastic cells.

Tissue expression of the tumour associated antigen CA242 in benign and malignant pancreatic lesions. A comparison with CA 50 and CA 19-9

“…The findings are in concordance with those for CA and CA 50 (Haglund et al, 1986a, b;Ichihara et al, 1988). The sequential change in antigenic distribution from normal epithelium to poorly differentiated and anaplastic carcinomas represents loss of polar distribution of membrane associated antigens, which has been described in various gastrointestinal carcinomas (Ahnen et al, 1982;Nagura et at., 1983;Ichihara et al, 1988) (Ouyang et al, 1987). The expression of CA 242 in normal and neoplastic epithelium of other gast-rointestinal organs is still poorly known.…”

Prognostic significance of CEA immunoreactivity patterns in large bowel carcinoma tissue

“…Our data therefore illustrate the practicality of characterizing tumours according to a feature heterogeneously expressed in relation to biological behaviour, which represents the outcome of the interrelation and interaction of several clones differeing in this feature. Nevertheless, our study confirms the observations of Ahnen et al (1982) and Hamada et al (1985) in that the pattern of CEA expression closely reflects the degree of differentiation of individual large bowel cancer cells and in addition demonstrates that tumours displaying a rather homogeneous membranous pattern of CEA expression behave aggresively.…”

“…However, there are indications that both the presence of CEA in tissue (Goldenberg et al, 1976) and its localization within the cell (Ahnen, et al, 1982;Hamada et al, 1985) are related to the histological grade of colorectal tumours and thus could be of potential prognostic value.…”

“…Yet, the pattern of CEA expression may be more relevant to study the biological behaviour of colorectal carcinomas than the intensity of the immunoreaction, which is variable and depends on several factors, such as tissue preservation and the affinity of the antibodies used. Ahnen et al (1982) observed a polar distribution of CEA using immunoelectronmicroscopy in the microvilli of the apical plasmamembranes of normal colonic epithelium, whereas in neoplastic epithelium a gradual loss of polarity occurred in relation to the grade of anaplasia. Poorly differentiated tumours demonstrated CEA over the entire cell surface.…”

Localisation of monoclonal antibodies reacting with different epitopes on carcinoembryonic antigen (CEA) – implications for targeted therapy

“…In malignant epithelium both these structures may hinder passage of antibody molecules. Ahnen et al (1982), demonstrated the localisation of CEA in normal intestine and colon cancer at the ultrastructural level using polyclonal antibodies. The results showed the association of CEA with basement membranes and basolateral surfaces of malignant colonic epithelium in tumours, in contrast to the apical distribution in normal colon, suggesting that the polarity of surface membrane components is disturbed in neoplasia.…”