IMMUNOHISTOCHEMICAL EXPRESSION OF TUMOR-ASSOCIATED GLYCOPROTEIN AND POLYMORPHIC EPITHELIAL MUCIN IN THE HUMAN ENDOMETRIUM DURING THE MENSTRUAL-CYCLE

An epitope defined by a second generation murine monoclonal antibody ( LU-BCRU-G7) produced against a breast tumour-associated fucosylated gl ycoprotein of M(r) 230 000 was found to exhibit phase specific reactiv ity in human endometrium during the menstrual cycle. Distribution and cycle related expression of the LU-BCRU-G7 determinant was different f rom the staining patterns observed with antibodies that react with the polymorphic epithelial mucins, HMFG 1 and NCRC 11, as determined by i mmunohistochemistry. Initial expression of the LU-BCRU-G7 determinant was associated with the peri-basal region of glandular epithelial cell s with maximal staining during the mid-secretory phase. Diffuse cytopl asmic staining was also observed from day 10 to day 26, with a marked increase in the early secretory phase. Reactivity of NCRC 11 also show ed maximal expression in the mid-secretory phase with no reactivity de tected in early and mid-proliferative phases. The HMFG 1 defined epito pe exhibited the opposite pattern of expression with maximal reactivit y in the proliferative phase and little or no reactivity in the secret ory phase. These findings suggest that expression of the LU-BCRU-G7, H MFG 1 and NCRC 11 defined determinants in the human glandular epitheli um of the endometrium is differentially hormonally regulated, and may be of value as markers for endometrial function.