Open AccessCharacterization of Carcinoembryonic Antigen‐related Antigens in Normal Adult Feces
Author(s) -
Matsuoka Yuji,
Matsuo Yoshino,
Sugano Kokichi,
Ohkura Hisanao,
Kuroki Motomu,
Kuroki Masahide
Publication year - 1990
Publication title -
japanese journal of cancer research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.035
H-Index - 141
eISSN - 1349-7006
pISSN - 0910-5050
DOI - 10.1111/j.1349-7006.1990.tb02600.x
Subject(s) - antigenicity , carcinoembryonic antigen , antigen , feces , epitope , chemistry , biology , microbiology and biotechnology , immunology , cancer , genetics
About 50–70 mg in total of carcinoembryonic antigen (CEA) (or CEA‐related antigens) was detected in normal adult feces evacuated during one day (200–250 g). Ten percent or less of the antigen was found to be in soluble form in fresh feces (naturally solubilized antigen), while 90% or more was still in membrane‐bound form which was releasable with phosphatidylinositol‐specific phospholipase C (PI‐PLC‐solubilized antigen). The naturally solubilized and PI‐PLC‐solubilized antigens are anti‐genically different from each other and similar to normal fecal antigen (NFA)‐2 and CEA, respectively, suggesting that “CEA‐distinctive’antigenicity detected so far in CEA from cancerous tissues is not due to the difference between antigens in normal and malignant tissues but is probably due to the presence of the glycosylinositolphosphate moiety at the carboxyl‐terminus of the antigen molecule. Thus, “CEA‐distinctive’antigenicity is by no means cancer‐specific, but this antigenicity seems to be critical for the clinical significance of CEA as a tumor marker, because an assay system (Kit II) which is able to distinguish CEA from NFA‐2 revealed much improved features in cancer diagnosis as reported recently.