I. Häkkinen

Immunological relationship of the carcinoembryonic antigen and the fetal sulfoglycoprotein antigen.

Abstract A simple immunological procedure was used for purification of CEA (carcinoembryonic antigen of colon cancer). Evidence is presented that CEA shares a common antigenic determinant with FSA (fetal sulfoglycoprotein antigen) of cancerous gastric juice. This determinant seems not to be identical with the true colon cancer specific antigen of the CEA macromolecule. Immunodiffusion data suggest the possibility that both determinants are to be found in the CEA macromolecule, while the colon cancer specific determinant is lacking in the FSA macromolecule. Unabsorbed anti-CEA contains antibodies to both determinants, the non-specific component can be removed only by an intensive absorption with colon tissue antigens, necessarily in particle form. The importance of the finding for the specificity of the radioimmunoassay of CEA is discussed.

Intestinal-type carcinoma of gallbladder. A histochemical and immunologic study.

Two intestinal carcinomas of the gallbladder are presented. In both carcinomas the structure was papillary in superficial parts; the deeper ones also tended to an adenomatous structure. One of the tumors was bordered by a mucosa, with both intestinal‐ and antral‐type metaplastic islands. The tumor was mainly a typical papilloma with malignant degeneration and infiltrative growth. The intestinal structure was morphologically clear in the papillary area of both carcinomas, but not distinct in the invasive part of the tumor. In both tumors, goblet cells and columnar cells with a distinct brush border were noted. Histochemical and immunologic methods were used in the identification of the glycoproteins of the tumor cells. With both methods the intestinal character of the tumor could be shown. A positive fluorescence was achieved with an intestinal antiserum in well‐differentiated tumorous areas containing goblet cells, as well as in the intestinal metaplastic areas. In the same areas the gallbladderspecific antigen was negative. The antiserum isolated from the normal gastric mucosa and corresponding to neutral glycoprotein gave a positive fluorescence only in the nontumorous metaplastic gastric superficial‐type epithelium, and in the metaplastic antral‐type glands.

FSA - Foetal Sulphoglycoprotein Antigen Associated with Gastric Cancer

The human alimentary canal is the seat of two common and feared malignant diseases, gastric and coionic cancer. The mucous cells or their precursors are thought to be the origin of malignant transformations and the development of a tumour. In the elucidation of the antigenic structure of gastric and coionic cancer cells, it seems likely that the ontogeny of the antigenic structures of normal mucous cells in the alimentary canal will provide valuable information (Gold & Freedman 1965, Hakkinen 1966, Hakkinen et al. 1968 a, Hakkinen etal. 1968 b). The present review includes a survey of the development of the antigenic structures of glycoproteins of the gastric mucosa and a comparison is made with the antigens of gastric cancer. Both coionic mucosa and cancer will be referred to in connection with the immunochemical analysis of the actual glycoprotein structures. Typical of mucous cells in the alimentary canal is the secretion of mucosubstances, sugar-rich glycoproteins, which are in effect extensions of the cell membrane, having a similar structure. The mucosubstances of the foetal mucosa have been histochemically characterized, their polyanionic nature depending on sulphate radicals (Stemmermann 1967, Hakkinen et al. 1968b). In young adult, sulphated glycoproteins are difficult to demonstrate histochemically in the gastric mucosa (Tyrkko et al. 1968) but they can be shown chemically in secreted glycoproteins, the low sulphation grade prevailing (Hakkinen et al. 1965). It is ontogenically interesting that in connection with malignancy, i. e. in gastric cancer cells, highly sulphated mucosubstances reappear and can be shown histochemically (Lev 1965, Jarvi, personal communication).

Gastric fetal sulphoglycoprotein antigen (FSA) and blood group antigens A and B.

Acid gastric glycoproteins deriving from 180 non-cancerous FSA secretors, 74 gastric cancer patients (FSA positives), and 28 young controls (FSA negatives), all in blood group A or B were analyzed for

Canine gastric glycoprotein antigens in early carcinogenesis

The effect of one single dose of N‐methyl‐N′‐nitro‐N‐nitrosoguanidine (MNNG) on the antigenic structures of gastric juice glycoproteins, was studied in dogs. Antisera to glycoproteins of the fetal alimentary canal were raised. Histologic mucosal specimens and glycoprotein fractions of gastric juice which were taken from four dogs during a 15.5‐month period after MNNG administration, were examined immunohistologically and by immunodiffusion for the appearance of fetal‐like antigens. Fetal‐like structures appeared in a stepwise manner in both the acid and neutral glycoprotein fractions of the gastric juice, and showed gradual crossreactivity between macromolecules obtained from gastric juice samples obtained during the observation period. Eight immunizations carried out using physicochemically different glycoprotein fractions of fetal canine alimentary canal mucosa, produced a similar response, thus indicating that the same antigenic structures are incorporated into all mucus glycoproteins, even though they do differ physicochemically. It is suggested that this “omnipotential” incorporation picture could also be found after exposure to MNNG and is, by its nature, typically fetal.