A NEW MARKER FOR HUMAN CANCER CELLS. 2. IMMUNOHISTOCHEMICAL DETECTION OF THE Ca ANTIGEN IN HUMAN TISSUES WITH THE Ca1 ANTIBODY

Expression of the CA1 determinant by carcinomas and by non-malignant epithelial cells in oral lesions

“…However, the reaction varied between specimens with regard to the number of positively stained cells and the intensity of the staining, and was generally weaker when compared with the adenocarcinomas of the breast. This finding seems consistent with the observation in the original report that the intensity of the staining with the Cal antibody varied among different cancers and that the weakest reactions were observed in the alimentary system, particularly colonic carcinomas (McGee et al, 1982). These authors suggested that those tumours which did not stain with the antibody might be composed of cells that expressed the Ca antigen below the level of detection by the immunoperoxidase reaction.…”

“…Therefore, we conclude that the staining with the Cal antibody can be attributed to binding with the Ca antigen which has previously been described to be trypsin resistant (McGee et al, 1982).…”

“…This was observed for the transitional epithelium of the urinary tract and for the luminal epithelium of the fallopian tube, and it led to the hypothesis that the Ca glycoprotein may protect cells from injury resulting from exposure to low pH McGee et al, 1982;McGee, personal communication). This view concurs with the observation that the Cal antibody also reacts with the epithelium of apocrine sweat glands in the axilla and the groin, as sweat may have a pH below 5 (Simpson et al, 1983).…”

“…Malignant breast tissue specimens were used as positive controls as it was reported that the carcinoma of the breast gave a strong staining with the Cal antibody (McGee et al, 1982). There were 2 infiltrating carcinomas and 2 intraductal carcinomas.…”

Heterogenous expression of cell-surface antigens in normal epithelia and their tumours, revealed by monoclonal antibodies

“…The antibody SSEA-1 shows heterogenous staining of colon, stomach and kidney carcinoma, although breast carcinoma was almost homogeneously positive (Fox et al, 1983). The antibody Cal (McGee et al, 1982) stains various tumours heterogeneously. These are only examples -many more have been reported.…”