Cytosolic estrogen and progestin receptors in human endometrium from different regions of the uterus

Enhancement of progesterone receptor levels by interferons in AE-7 endometrial cancer cells

BACKGROUND

Interferon (IFN) has been reported to increase hormone receptor expression in breast cancer cells and to sensitize them to antiproliferative hormones. Endometrial cancer cells with high progesterone receptor (PR) level respond better to progesterone therapy than cells with either low or absent PR level. The effect of four different interferons (alpha and beta, both natural [n] and recombinant [r]) on cell proliferation and steroid receptor levels was investigated in the PR positive AE-7 human endometrial cancer cell line over a period of 12 days.

METHODS

Cells were exposed to 10,100 and 1000 IU/ml of each IFN either for 3 days or continuously for 12 days. Hormone receptors were determined by the monoclonal enzyme immunoassay. Chemosensitivity was evaluated with the adenosine triphosphate-cell viability assay.

RESULTS

AE-7 has a low level of estrogen receptors, which was not significantly affected by IFN exposure. The four IFN showed significantly enhanced PR levels over 12 days in both the 3-day and continuous-exposure experiments. No significant difference of PR enhancement was observed between 3 days and continuous exposure to IFN. This increase of receptors did not appear to be dose related. IFN enhanced PR level to a maximum level of about two times control cells. IFN did not produce significant cytotoxicity. Antiproliferative activity was observed with nIFN beta and rIFN beta at 1000 IU/ml dose in continuous-exposure experiments, which showed survival values of 79% and 69% respectively, compared with control at day 12.

CONCLUSIONS

These preliminary data on PR expression modulation support other studies, which have shown that IFN modulate hormone receptor expression and, therefore, may play a role in the treatment of endometrial cancer.

Distribution of total progesterone receptor levels in various segments and tissues of the normal human uterus: the effect of short-term estrogen administration

Total progesterone receptor levels (TRP) were measured in various tissues and segments of normal human uteri in basal conditions (late proliferative phase, control group, n = 6) and after short term estrogen administration (test group, n = 8). Similar trends of distribution were observed in both groups in basal endometrial TRP levels along the longitudinal axis, i.e. the highest levels were found at the height of the body and the lowest at the height of the internal os. Differences were found in the trends of distribution of the TRP levels between the two groups along the transverse axis of the uterus at the height of the fundus. In the control group TRP levels in the functional endometrium were higher than those in the basal endometrium and myometrium. In the test group, however, the trend was reversed. Since the RP is estradiol induced and dependent, these results indicate the possibility of a selective estrogen effect on various segments or tissues in the human uterus.

Endometrial adenocarcinoma estrogen receptor content: association of clinicopathologic features with immunohistochemical analysis compared with standard biochemical methods

Endometrial adenocarcinomas from 96 patients were studied for their biochemical estrogen receptor content as well as immunohistochemical localization of estrogen receptor. A well-characterized specific monoclonal antihuman estrogen receptor antibody (H222 sp gamma) as amplified by peroxidase/antiperoxidase techniques was used for immunohistologic localization. Immunohistochemical evaluation incorporated both the intensity and distribution of staining into a semiquantitative analysis (HSCORE). The total HSCORE was the sum of the relative contributions of the four histologic components: benign epithelium, malignant epithelium, stroma, and myometrium. These results were compared with clinicopathologic features of the tumors. Excellent sensitivity (91.5%) and specificity (93.1%) were observed for immunohistochemical analyses as compared with the biochemical analysis of estrogen receptor for these tissues. The cancer component HSCORE correlated better with grade than did the biochemical estrogen receptor determination. Correlation was also observed between surgical stage and estrogen receptor content. Decreasing biochemical estrogen receptor content predicted advanced surgical stage (p = 0.0003), as did the total HSCORE (p = 0.003); however, the HSCORE of the cancer component only did not correlate with advanced surgical stage (p = 0.11). Although immunohistochemical analyses predicted biologic differentiation better than did the biochemical technique, stage correlated better with biochemical estrogen receptor analysis and total HSCORE than did the cancer component HSCORE. The HSCORE of the cancer component may better predict biologic behavior and therefore identify cancers more likely to respond to hormonal therapy.

Short-term effects of danazol and medroxyprogesterone acetate on cytosol and nuclear estrogen and progestin receptors, 17 beta-hydroxysteroid dehydrogenase activity, histopathology, and ultrastructure of human endometrial adenocarcinoma

We measured concentrations of cytosol and nuclear estrogen, as well as progestin receptors and activities of 17 beta-hydroxysteroid dehydrogenase (17-HSD), and examined histopathology and ultrastructure of endometrial carcinoma specimens taken before and after one-week danazol (200 mg, 3 times daily) or medroxyprogesterone acetate (MPA, 100 mg daily) treatments in 14 and 16 patients, respectively. A typical progestin effect, a significant increase in the activity of 17-HSD, was observed after both treatments. The post-therapy 17-HSD activities correlated significantly with the pretreatment cytosol progestin receptor concentrations in both treatment groups. Both MPA and danazol decreased the proliferative activity and increased the secretory activity of the malignant epithelial endometrial cells. These biochemical and morphological results support the concept that danazol has progestin-like actions on the human endometrium, and might therefore be an alternative for hormonal treatment of endometrial carcinoma.

Tamoxifen and endometrial carcinoma: alterations in estrogen and progesterone receptors in untreated patients and combination hormonal therapy in advanced neoplasia

Estrogen receptors and progesterone receptors were measured in tumors from patients with previously untreated endometrial carcinoma before and after a 5-day course of tamoxifen citrate. On initial biopsy, 13 of 25 tumors (52%) were progesterone receptor-positive, whereas 21 of 25 tumors (84%) were progesterone receptor-positive after tamoxifen. Grades 1 and 2 tumors were more likely to demonstrate this increased incidence of measurable progesterone receptors. Considering these results, and the work of others who have shown that progesterone receptor-positive metastatic endometrial cancer is more responsive to progestin therapy than are progesterone receptor-negative tumors, we instituted a phase II clinical trial of tamoxifen plus progestin for patients with recurrent endometrial carcinoma. Thus far, however, the 33% total response rate achieved with the combination therapy has not been superior to standard progestin therapy.

Female sex steroid receptors in gynecological malignancies: clinical correlates

Cytosol estrogen (ERc) and progestin (PRc) receptors were measured in 135 endometrial carcinoma specimens from 127 patients, and in 84 ovarian carcinoma specimens from 84 patients before any treatment. In endometrial carcinoma, early clinical stages (I and II) were more often receptor-rich (ERc and PRc greater than or equal to 30 fmol/mg cytosol protein) than stage III-IV tumors, or metastatic and recurrent lesions. Anaplastic lesions (grade 3) had lower receptor concentrations than moderately (grade 2) and well (grade 1) differentiated stage I lesions. PRc concentrations of the stage I malignancies clearly infiltrating into the myometrium were lower than those in superficial tumors. Our follow-up (24 months or more) data of 41 patients with clinical stage I disease, and of 21 patients with clinical stage III or IV disease show that the receptor-poor tumors tend to behave more aggressively than receptor-rich malignancies in relation to patient survival. In 59 primary epithelial ovarian carcinomas, there were no significant differences in ERc and PRc concentrations in the four clinical stages. In contrast to this, the concentrations of these receptors were significantly lower in recurrent than in primary epithelial carcinomas. In anaplastic serous carcinomas, PRc was significantly lower than in differentiated tumors, and in anaplastic endometrioid carcinomas, ERc and PRc were lower than in corresponding differentiated tumors. Follow-up (24 months or more) data of 22 patients show that patients with advanced ovarian malignancy characterized by low ERc and/or PRc concentrations survive for a shorter time than the other patients.