CATHEPSIN-D IN HUMAN-ENDOMETRIUM - INDUCTION BY PROGESTERONE AND POTENTIAL VALUE AS A TUMOR-MARKER

Using an immunoenzymatic assay, cathepsin-D concentrations were measured in the cytosol of human endometrium biopsies. The level of cathepsin-D was higher in the luteal phase than in the follicular phase (P < 0.01), suggesting increased accumulation by progesterone. Induction by progestin was confirmed by immunoprecipitation of cathepsin-D from a lysate of epithelial endometrial cells previously treated in primary culture with R5020 (10 nm); estradiol (10 nm) had no effect. Immunohistochemistry showed that cathepsin-D is mainly localized in the epithelium and that its level is higher in the luteal phase. The plasma level of cathepsin-D was stable during the menstrual cycle, ranging between 2.5-10 pmol/mL, but increased slightly during pregnancy. The mean level of cathepsin-D was higher in 19 endometrial carcinoma than in 20 normal endometrium, but was not correlated with steroid receptor status. However, using 15 pmol/mg protein as a cut-off level, the cathepsin-D status (high or low) was correlated with the degree of myometrial invasion (one third) by adenocarcinoma cells, whereas steroid receptor status was not. We conclude that cathepsin-D is induced by progesterone in human endometrium, as it is in normal rat uterus, and we suggest that a low concentration of cathepsin-D in the cytosol of endometrial adenocarcinoma may indicate a favorable prognosis, since it is correlated with low myometrial invasion. © 1990 by The Endocrine Society.