Takaya Tamura

Evidence for estrogen synthesis in adenomyotic tissues

OBJECTIVE To investigate steroidogenesis in eutopic and ectopic endometrial tissues in adenomyosis. STUDY DESIGN Aromatase and estrone sulfatase activities were determined by anion-exchange resin column chromatography, thin-layer chromatography, and cocrystallization. The effects of danazol on the activity of these enzymes were also examined. Moreover, localization of aromatase in eutopic and ectopic endometrial tissues was immunohistochemically examined with antihuman placental aromatase cytochrome P-450 antibody. RESULTS Aromatase and estrone sulfatase activities were detected in ectopic endometrium. The activity of these enzymes was significantly suppressed by danazol. In addition, aromatase was immunohistochemically detected in glandular cells of eutopic and ectopic endometrial tissues. CONCLUSIONS The results suggest that estrogen is synthesized in the eutopic and ectopic endometrial tissues of women with uterine adenomyosis and that it may affect the growth of adenomyosis. Danazol suppressed synthesis of estrogen in vitro.

Estrogen as a growth factor to central nervous cells. Estrogen treatment promotes development of acetylcholinesterase-positive basal forebrain neurons transplanted in the anterior eye chamber.

In a previous report, we demonstrated in vivo ameliorating effects of conjugated estrogen in women suffering from senile dementia-Alzheimers type. To investigate the effects of estrogen on the growth of cholinergic neurons, the present study was performed using rat cholinergic tissue implanted into the anterior chamber of the eye. Fetal diagonal band tissue containing cholinergic neurons was grafted into the anterior eye chamber of adult female rats that had either been treated or not with 2 mg estradiol valerate injected every 3 days after oophorectomy. Two and four weeks after transplantation, the axonal and/or dendritic growth of cholinergic neurons in the graft was studied using acetylcholinesterase histochemistry. At both times, acetylcholinesterase positive processes were densely distributed in the grafts of estradiol valerate treated rats, while in rats without estradiol valerate treatment acetylcholinesterase positive reaction was essentially localized only on the cell bodies. These findings were more obvious at 2 weeks after transplantation than at 4 weeks. These results suggest that estrogen acts on cholinergic neurons as a growth factor.

Estrogen productivity of endometrium and endometrial cancer tissue; influence of aromatase on proliferation of endometrial cancer cells.

Aromatase, estrone (E1) sulfatase and E1 sulfotransferase activities were examined in endometrium and endometrial cancer tissue preparations. Aromatase and E1 sulfatase activities in endometrial cancer tissues were found to be significantly higher than in normal endometrial tissues. However, E1 sulfotransferase activity did not differ between benign and malignant tissue. We also examined the effect of testosterone (T) on aromatase activity and tritiated thymidine uptake (DNA synthesis) in various cultured cervical or corpus endometrial cancer cell lines (OMC-4, HHUA, Ishikawa, HEC-59). The results demonstrated that only the HEC-59 cell line had high aromatase activity and increased its DNA synthesis in response to T. This increase of DNA synthesis by T was not suppressed by simultaneous addition of cyproterone acetate, but was by tamoxifen. These data suggest that in situ estrogen production in endometrial cancer tissue is biologically important and that aromatase in cancer cells may contribute partially to cell proliferation if androgen substrate is provided.

Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels in women with or without gynecologic cancer.

Objective: To detect the level of 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG) which is an oxygen‐radical‐forming agent, in the urine of patients with (n = 18) or without (n = 10) carcinoma of the female genitalia. None of the patients had been receiving any treatment before their urinary 8‐OHdG levels were measured.

Relationship between aromatase activity and steroid receptor levels in ovarian tumors from postmenopausal women

Aromatase activity, as well as steroid receptors, exists in nonfunctional ovarian tumors. Steroid receptor status has been reported to be related to prognosis in ovarian cancer patients. We determined aromatase activity and progesterone receptor (PR) and estrogen receptor (ER) levels in 43 ovarian tumors obtained from postmenopausal women. Aromatase activity was detected in 35 tumors (81%), PR in 21 tumors (49%) and ER in 13 tumors (30%). Eighty-three percent (10/12) of mucinous cystadenoma tissues showed positive PR with high aromatase activity, while 93% (13/14) of malignant tumors showed negative PR and low aromatase activity. Aromatase activity was detected in 95% (20/21) of PR-positive tumors, being greater than in PR-negative tumors (P < 0.002). There was a positive correlation between aromatase activity and PR (rs = 0.49, P < 0.001). However, there was no correlation between aromatase activity and ER. In 17 patients (43%), the serum estradiol level was higher than 30 pg/ml and there was a positive correlation among estradiol, estrone, androstenedione and testosterone. However, serum steroid levels were not correlated with aromatase activity, PR or ER. Aminoglutethimide inhibited aromatase activity of benign and malignant ovarian tumors, uterine myoma, choriocarcinoma cells and purified human placental P-450arom in a similar manner. These results suggest that aromatase activity is correlated with PR in ovarian tumors of postmenopausal women. In addition to steroid receptor status, aromatase activity may be a useful prognostic factor in ovarian cancers.

Cigarette smoking during pregnancy lowers aromatase cytochrome P-450 in the human placenta

To clarify whether cigarette smoking during pregnancy causes an organic alteration in placental estrogen producing ability, we determined the catalytic activity of aromatase by the tritiated water assay, and tissue level of aromatase cytochrome P-450 (P-450arom) by the specific enzyme-linked immunosorbent assay, in placental samples from nonsmokers and smokers. As pregnancy progressed, both aromatase activity and P-450arom concentration increased in placentas from nonsmokers and smokers. However, the gradient of the increase was significantly less in heavy smokers (> or = 20 cigarettes a day) than in normal and moderate smokers (< 20 cigarettes a day). At term, the mean aromatase activity and P-450arom concentration in placentas from heavy smokers were significantly lower than in nonsmokers and moderate smokers, while aromatase activity per P-450arom (turnover rate) and the mean placental weight were comparable among the three groups. In contrast, the ratio of aryl hydrocarbon hydroxylase activity to aromatase activity was higher in placentas from heavy smokers. Immunohistochemical studies showed that P-450arom was localized in the cytoplasm of syncytiotrophoblasts of chorionic villi in placentas from both nonsmokers and smokers. These results suggest that the induction of placental P-450arom during gestation is suppressed by maternal smoking, resulting in a reduction in estrogen producing ability, while placental xenobiotic P-450 is induced.

Alzheimer's disease and estrogen

The preventive effect of estrogen on Alzheimers disease (AD) has become clear with epidemiological data. Therapeutic effects of estrogen have not yet been established. In this presentation, we report our new basic and clinical data. The estrogen receptor, (ER)alpha, and ERbeta mRNA were investigated in rat brain. Estradiol-17beta (E(2)) treatment following OVX reduced the levels of ERalpha mRNA in the hypothalamus. In the substantia innominata (SI), the number of choline acetyltransferase immunoreacive cells increased significantly in the estrogen treatment rat. The neurons in SI projecting to the forebrain cortex contained ERalpha. Increasing amounts of intracellular calcium, peroxidation, and apoptosis with amyloid beta were suppressed in neuronal cells from rat pheochromocytoma (PC12) cells with E(2). ERalpha cDNA transfected PC 12 cells elaborated more neurite-like processes with E(2). In clinics, we are currently preparing vaginal progesterone tablets, which essentially may concentrate in the endometrium to prevent endometrial cancer, with few general circulation of progesterone inviting less depression. The therapeutic effects of cyclic estrogen, such as its preventive effect, are suggested in these studies, at least on mild AD.

Expression of exon 5 deleted estrogen receptor variant messenger RNA in human uterine myometrium and leiomyoma

To examine the relationship between uterine leiomyoma, an estrogen-dependent tumor and its estrogen receptor, the relative amounts of wild type estrogen receptor (WT) mRNA and exon 5 deleted estrogen receptor variant (D5-ER) mRNA to G3PDH mRNA were examined in human uterine myometrium and leiomyoma specimens obtained from 46 patients in 3 age groups (group A: 41-45 years old, group B: 46-50 years old, group C: 51-54 years old) using a quantitative reverse transcription polymerase chain reaction method (RT-PCR). D5-ER mRNA was co-expressed with WT mRNA in all myometrium and leiomyoma specimens. In myometrium, the relative amount of WT decreased with aging, but in leiomyoma, it was high in group B. The relative amount of D5-ER mRNA and the ratio of D5-ER mRNA to WT mRNA (D5/WT ratio) were significantly higher in group C in both myometrium and leiomyoma. The percentage of the patients whose D5/WT ratio was higher in leiomyoma than in myometrium (L/M ratio>1.0) increased with age. These findings suggest that D5-ER increases to supplement the decreasine in WT in uterine tissues toward menopause and that D5-ER plays a more active role in leiomyoma than in myometrium during the perimenopausal period.

Expression of Nuclear Factor of Activated T Cells mRNA in Maternal Peripheral Blood Cells

PROBLEM:  In T lymphocytes, nuclear factor of activated T cells (NF‐AT) regulates the induction of cytokine genes upon antigenic stimulation. This study was designed to analyse the relationship between NF‐AT and pregnancy.

Expression of IL-4, IL-8 and IL-18 Messenger RNAs in Maternal Peripheral Blood and Relationships with the HbF-γ chain mRNA in it

Problem:  This study was designed to examine immunological changes in maternal peripheral blood and the relationship of these changes with the amount of fetal cells in the blood.