Pregnancy-associated beta 1-macroglobulin: detection on the surface of ovarian cancer cell lines.

Pregnancy-associated beta 1-macroglobulin (beta 1-PAM) is a serum protein which can be detected at elevated levels in the blood of many ovarian cancer patients. The presence of the antigen was investigated on the surface of 4 human ovarian cancer lines and 32 other human and rodent cell types and lines by means of immunofluorescent staining and anti-beta 1-PAM-enzyme conjugate. The antigen was detected only on the ovarian lines but no secretion of beta 1-PAM into the culture supernatants was observed. The ovarian cancer cells appeared to display the beta 1-PAM constantly during culture, and enzymic treatment of the cells indicated that detection of the cell-bound antigen with antiserum could be, at least partially, eliminated with proteases but not glycosidases or neuraminidase. The results serve to confirm the association of beta 1-PAM with ovarian cancer.