Mamoru Urabe

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.

Estrone sulfate and sulfatase activity in human breast cancer and endometrial cancer

Estrone sulfate (E1-S) in the serum and tissues of patients with breast cancer or endometrial cancer was measured by a direct radioimmunoassay without hydrolysis. The concentration of E1-S in breast cancer tissue was 1.64 +/- 0.28 ng/g wet wt (+/- SE), lower than in surrounding normal breast tissue (4.46 +/- 1.23). Estradiol-17 beta(E2)/E1-S was higher in endometrial cancer tissue than normal endometrial tissue. Estrone sulfatase activity in breast cancer tissue was 0.81 +/- 0.23 nmol/h/mg protein, higher than in surrounding normal breast tissue (0.35 +/- 0.11). These results suggest that E1-S, which is abundant in the peripheral circulation, is hydrolyzed by sulfatase in breast cancer tissue or endometrial cancer tissue and liberates free estrogens, which may stimulate the growth of these malignant tumors.

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.

Atheroprotective effect of estriol and estrone sulfate on human vascular smooth muscle cells

In patients with atherosclerosis, fibrosclerotic focuses are induced by multiplication of vascular smooth muscle cells (VSMC), and they are regulated by cytokines and regulators. There have been few reports about the atheroprotective effect of estriol (E(3)). Estrone sulfate (E(1)-S) is the predominant estrogen of conjugated equiline estrogens, which is commonly used in hormone replacement therapy, but it should be hydrolyzed by steroid sulfatase (STS) to enter the cells of target tissues. The purpose of this study was to detect STS in VSMC and to investigate whether E(3) and E(1)-S have atheroprotective effects like E(2). First, we detected the presence of STS mRNA in VSMC by in situ hybridization. We then examined the changes in the expression of mRNAs of cytokines, namely, PDGF-A chain, IL-1, IL-6 and TGF-beta, in VSMC, in the presence and absence of E(3) and estrogens. As a result, the expression of PDGF-A chain, IL-1 and IL-6 mRNAs was suppressed by E(3) (P<0.05 vs control) significantly like E(1)-S and E(2), but that of TGF-beta mRNA was not significantly affected by any estrogen. These results indicate that E(1)-S can be hydrolyzed by STS in VSMC, and that E(3) may regulate the cytokines by suppressing the production of mRNAs. It is suggested that there is a possibility of E(1)-S and E(3) having a direct effect on vessels in atherogenesis.

Serum and urinary estrone sulfate during the menstrual cycle, measured by a direct radioimmunoassay, and fate of exogenously injected estrone sulfate

Serum and early-morning urinary levels of estrone sulfate during the menstrual cycle were measured by a direct radioimmunoassay without hydrolysis. These levels were high and showed prominent peaks [serum, 2.67 +/- 0.37 ng/ml (mean +/- SE); urine, 5.82 +/- 2.3 micrograms/l] around the day of the preovulatory estradiol-17 beta peak, and increased again during the luteal phase. Following intravenous injection of estrone sulfate, serum estrone sulfate, estrone and estradiol-17 beta were measured. The conversion of estrone sulfate to estrone and/or estradiol-17 beta was very small during their transit in the general circulation.

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.

Estrone sulfatase activity in human uterine leiomyoma

Human uterine leiomyoma is a benign tumor and its development is closely related to estrogen. In this study, estrone sulfatase (E1SF) activity and concentrations of estrone (E1) and estrone sulfate (E1S) were measured in endometrial, leiomyoma, and myometrial tissues of the same human uterus (n = 11) with a leiomyoma. E1SF activity in endometrial tissue overlying a leiomyoma was 2.62 +/- 0.29 nmole/hr/mg protein (mean +/- SD), this activity being significantly higher (P less than 0.01) compared with that in normal endometrial tissue (2.0 +/- 0.24 nmole/hr/mg protein). E1SF activity in normal endometrial tissue was significantly higher (P less than 0.001) compared with that in leiomyoma tissue (0.49 +/- 0.82 nmole/hr/mg protein) or myometrial tissue (0.76 +/- 0.10 nmole/hr/mg protein). We also found a significant difference (P less than 0.05) in E1SF activity between leiomyoma tissue and myometrial tissue. On the other hand, the E1 concentration in endometrial tissue overlying a leiomyoma (10.9 +/- 8.9 pg/mg protein) proved to be higher than that in endometrial tissue overlying normal myometrium (1.23 +/- 1.97 pg/mg protein). E1S concentrations in these tissues, however, were 631 +/- 339 and 902 +/- 482 pg/mg protein, respectively, these values showing a trend opposite that of the E1 concentration data. Thus, these results suggest that high E1SF activity and high E1 concentration in the endometrium overlying a leiomyoma may be related to estrogen supply to a uterine leiomyoma node.

Aromatization of norethindrone to ethynylestradiol in human adult liver [Poster 41]

Homogenates of human adult liver are capable of aromatizing norethindrone (17 alpha-ethynyl-19-nortestosterone) to ethynylestradiol (17 alpha-ethynylestradiol). The evidence of ethynylestradiol formation was obtained using a Bio-Rad AG1-X2 column, thin layer chromatographies and co-crystallization. Neither acid nor base was used in any step in product identification.

Autoamputation of a pedunculated, subserosal uterine leiomyoma presenting as a giant peritoneal loose body.

Peritoneal loose bodies (PLBs) are defined as fibrotic or calcified-free bodies within the peritoneal cavity; they commonly autoamputate from appendices epiploicae that have undergone torsion. Pedunculated, subserosal uterine leiomyomas (PSULs) are subserosal uterine leiomyomas connected to the uterus via a pedicle. In the present report, we describe the case of a PLB that originated from the autoamputation of a PSUL, confirmed based on histological evidence consistent with a uterine leiomyoma and the laparoscopic findings of a broken pedicle. This case clearly demonstrates the potential for a uterine leiomyoma to be the source of a PLB. Our findings contribute to the understanding of the etiological relationship between PLBs and uterine leiomyomas.

Transformation of estrone, estradiol, and estrone sulfate in uterine and vaginal isolated cells of fetal guinea pig. Effect of various antiestrogens in the conversion of estrone sulfate to estradiol.

The metabolism of physiological concentrations (5 x 10(-9) M) of [3H]estrone (E1), [3H]estradiol (E2), and [3H]estrone sulfate (E1S) was studied in isolated fetal uterine and vaginal cells of guinea pigs in culture. After 24 hours of incubation in both cells, a large percentage (40-60%) of E1 is converted to E2; however, after incubation of E2, most of the radioactive material (45-65%) corresponds to unchanged E2. Similarly, in the incubation medium the concentration of E2 is significantly higher related to E1 after incubation with E1 or E2. An intense sulfotransferase activity is found for both estrogens, whereas in the culture medium the respective sulfates represent 27-45% of the total radioactive material after incubation with the uterine cells and 15-24% for the vaginal cells. Using E1S, significant hydrolysis is observed in both cells and the analysis of the freed radioactive material indicated a high percentage in E2 (66% in the uterine cells and 71% in the vaginal cells). The conversion of E1S to E2 was strongly decreased by the antiestrogens: tamoxifen, 4-hydroxy-tamoxifen, and ICI 164,384. The inhibitory effect in relation to the incubation with E1S only was 43-66% in the uterine cells and 50-85% in the vaginal cells. The present data suggest that estrogen sulfates can play an important biological role in the target tissues of the fetus, and that the enzymatic mechanisms of the bioavailability of E2 for the biological responses of the hormone can be operated in the target tissue itself.