Immunohistochemical expression of tumour-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 glycoprotein of M(r) 230,000 was found to exhibit phase specific reactivity in human endometrium during the menstrual cycle. Distribution and cycle related expression of the LU-BCRU-G7 determinant was different from the staining patterns observed with antibodies that react with the polymorphic epithelial mucins, HMFG 1 and NCRC 11, as determined by immunohistochemistry. Initial expression of the LU-BCRU-G7 determinant was associated with the peri-basal region of glandular epithelial cells with maximal staining during the mid-secretory phase. Diffuse cytoplasmic staining was also observed from day 10 to day 26, with a marked increase in the early secretory phase. Reactivity of NCRC 11 also showed maximal expression in the midsecretory phase with no reactivity detected in early and mid-proliferative phases. The HMFG 1 defined epitope exhibited the opposite pattern of expression with maximal reactivity in the proliferative phase and little or no reactivity in the secretory phase. These findings suggest that expression of the LU-BCRU-G7, HMFG 1 and NCRC 11 defined determinants in the human glandular epithelium of the endometrium is differentially hormonally regulated, and may be of value as markers for endometrial function.