Summary In order to examine the production of marker proteins, a reproducible method has been established for culturing purified epithelial cells from normal and malignant endometrium. We have examined the differential expression of secretory proteins using immunohistochemistry in frozen tissue sections, immunocytochemistry in cell cultures derived from the same specimens and protein assays on the culture supernatants. Placental al., 1993) and those apparently cured of their endometrial cancer, who yet wish to receive the benefits of hormone replacement therapy (Creasman et al., 1991).Placental protein 14 (PP14) (Bolton et al., 1983) is one of the major proteins secreted by the normal endometrium and the decidua in early pregnancy (Bell et al., 1985;Julkunen et al., 1985). Placental alkaline phosphatase (PLAP), an isoenzyme of the alkaline phosphatase group (Fishman et al., 1968), originally isolated from human trophoblast, is also expressed in other non-malignant human tissues (Goldstein et al., 1982;McLaughlin et al., 1984). PLAP is found to be elevated in the sera of some patients with cancers, particularly those of the reproductive tract (Nathanson & Fishman 1971;Wahren et al., 1979). The beta subunit of human chorionic gonadotrophin (P-hCG), a normal product of the trophoblast, and CA-125 (Bast et al., 1981) are both wellcharacterised oncofetal antigens (Braunstein, 1983) found to be synthesised by many normal tissues and epithelial carcinomas of the reproductive tract.We have established an in vitro system for the culture of normal and malignant endometrial epithelium. The differential expression of markers has been characterised in frozen tissue sections, primary cell cultures and in an established endometrial cell line, in order to demonstrate their specific production by the cancers as a preliminary to evaluating their use as clinical markers.
Materials and methods
TissuesSamples of human endometrium were obtained during normal non-conceptional menstrual cycles from women undergoing diagnostic curettage for gynaecological investigations. In the premenopausal tissues the phase of the menstrual cycle was determined from the last menstrual period and conCorrespondence: C.J. Gallagher. Received 15 October 1993; and in revised form 24 January 1994.firmed by histology as being proliferative (n = 10), secretory (n = 11) or mid-cycle (n = 10). The endometrium was normal by histological examination, and no other gynaecological abnormality was present except in three cases of endometriosis and two of cervical carcinoma in situ (CIN III). Five samples of perimenopausal endometrium with weak proliferative activity (n = 4) or inactive under hormone replacement therapy (n = 1) were obtained from hysterectomies for fibroids (n = 4) or CIN III (n = 1). Samples from postmenopausal women were also obtained from patients undergoing hysteroscopy or hysterectomy; two of these were atrophic, two showed simple hyperplasia and 17 were histologically diagnosed as well-differentiated endometrial adenocarcinoma. None of these...
