[Localization of embryonic prealbumin-1 in the tissues of human malignant tumors].

The distribution of human embryonic prealbumin-1 (EPA-1) has been studied in 52 different malignant tumours using indirect immunofluorescent technique and two types of antibodies to different antigenic determinants: "EPA-1" and "EPA-1S". In mesenchymal tumours (except for desmoids and chondrosarcomas) this glycoproteid was observed in the cytoplasm of tumour cells, but "EPA-1S"--in the connective-tissue fibers only. Localization of glycoproteid EPA-1 depends on the type of the used primary antibodies. EPA-1 is also observed in the connective-tissue stroma of most of epithelial tumours. A conclusion is made that transformation of EPA-1 glycoproteid synthesis from definitive to fetal form occurs in malignant tumours.