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In vivo inhibition of estrone sulfatase activity and growth of nitrosomethylurea-induced mammary tumors by 667 COUMATE.

The development of potent steroid sulfatase inhibitors is an important new therapeutic strategy for the treatment of postmenopausal women with breast cancer. A series of tricyclic coumarin sulfamates were synthesized, and their inhibitory properties were examined in vitro and in vivo. In a placental microsomal assay system, 667 COUMATE emerged as the most potent inhibitor with an IC50 of 8 nM. Administration of a single dose (10 mg/kg, p.o.) of 667 COUMATE inhibited rat liver estrone sulfatase activity by 93%. 667 COUMATE was devoid of estrogenicity, as indicated by its failure to stimulate the growth of uteri in ovariectomized rats. In vivo, estrone sulfate-stimulated growth of uteri in ovariectomized rats was inhibited by 667 COUMATE. Using the nitrosomethylurea-induced mammary tumor model, we found that 667 COUMATE caused regression of estrone sulfate-stimulated tumor growth in a dose-dependent manner. The identification of 667 COUMATE as a potent steroid sulfatase inhibitor will enable the therapeutic potential of this type of therapy to be evaluated.

Animals↗

[Morphometric study on the effects of estrone on bone in vitro].

AIM: To study the effects of estrone on the bone resorption and bone formation in vitro. METHODS: Long bones from 16-day-old female mouse fetuses were cultured in BGJb medium for 48 h. The bones were harvested, then bones length and length of their diaphyses were measured under stereo microscope. The histomorphormetric analyses on midlongitudinal sections of bones were performed. The numbers of osteoclasts and hypertrophic chondrocytes were observed under biological microscope. RESULTS: Compared with control, there were significant increase in bones length and length of their diaphyses after treated with 10(-7) mol/L estrone. Under this condition, decreased osteoclasts and increased hypertrophic chondrocytes were observed, too. CONCLUSION: Estrone stimulates bone formation and inhibites bone resorption in vitro.

Animals↗

C-mycprotein expression upregulated by 2-(3-estrone-N-ethyl piperazine-methyl) tetracycline in bone.

AIM: To study the effect of XW630 on expression of pro-oncogene c-myc in the long bones of fetal mice in vitro for postulating the mechanism by which XW630 exerts its effect on bone. METHODS: The fetuses of pregnant mice were removed on day 16 of gestation, the long bones of the forelimbs of female fetal mice were freed of muscle and soft tissue and cultured in a specific device for 48 h in BGJb medium treated with 1 x 10(-7), 1 x 10(-8) and 1 x 10(-9) mol.L-1 XW630 in the final medium. After cultured for 48 h, the long bones were harvested and immunohistochemical analysis was performed for determination of c-Myc protein expression in epiphyseal plates. The areas of positive cells in the resting zone, proliferative zone and hypertrophic zone in epiphyseal plate were determined under image analytic system. RESULTS: When the concentration of XW630 in the medium was 1 x 10(-9) mol.L-1, the area of c-Myc positive cells increased in the proliferative zone compared with 1 x 10(-9) mol.L-1 in the estrone group, significant increase was also observed in the resting zone compared with the control group. When the concentration of XW630 in medium was 1 x 10(-8) or 1 x 10(-7) mol.L-1, stronger expression than that in the control group and the estrone group at the same concentration was observed in each of the three zones. CONCLUSION: The estrogenic effect of XW630 on bone was stronger than that of estrone. XW630 may promote proliferation and differentiation of chondroncytes by promoting c-Myc protein expression in chondroncytes. Thus, endochondral bone formation was enhanced.

Animals↗

Longitudinal evaluation of serum estradiol and estrone in male patients infected with the human immunodeficiency virus.

In patients with human immunodeficiency virus (HIV) infection alteration of various endocrine functions have been described. However, there is limited information available on estrogens and their function in these patients. The aim of this study was to evaluate the pituitary and testicular endocrine markers: 14 HIV-positive men were included into the longitudinal study with a follow up to of 18 month period. None of the patients had a history or clinical evidence of endocrine dysfunction. Follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin, estrone, estradiol, and testosterone were measured in serum by commercially available radioimmunoassays. Prolactin levels were not affected in the patients. LH and FSH remained within normal range, but at the end of the study period we observed a significant increase of LH (p < 0.05). In addition, testosterone levels were normal with a slight reduction at the end of the 18-month observation period (p <0.05). Both estrone and estradiol were significantly increased with a further rise at the end of the study (p <0.05). In summary, the elevation of the serum estrone and estradiol in HIV-afflicted patients correlated with the progress of the HIV-disease, being paralleled by a decrease in testosterone. The altered relation of estrogens and testosterone may in a part be responsible for the complaints of decreased libido and increased impotence often observed in HIV-infected men.

Adult↗

Neuroprotective effects of estrone on NMDA-induced toxicity in primary cultures of rat cortical neurons are independent of estrogen receptors.

It has been hypothesized that some estrogenic metabolites with low hormonal activity, such as estrone or estriol, may serve as endogenous neuroprotective agents. Since estrone naturally occurs in abundance in the human brain, we evaluated its effects on the NMDA-induced toxicity in primary cultures of the rat cortical neurons. The results showed that NMDA (1 mM) had toxic effect on the rat cortical neurons on 12, but not on 7 day in vitro. This effect was partially prevented by DL-2-amino-5-phosphonovaleric acid (AP-5); a competetive NMDA receptor antagonist. Estrone (500 nM) attenuated the NMDA-induced toxicity in estrogen receptor-independent way. These data support the hypothesis that toxic effects of NMDA depend on stage of neuronal development and point to non-genomic neuroprotective actions of estradiol metabolites.

Animals↗

[Estrone Reference Standard (Control 021) of National Institute of Health Sciences].

The raw material of estrone acetate was examined for the preparation of the "Estrone Reference Standard (Control 021)", The analytical data obtained were: UV spectrum, lambda max of 281 nm and specific absorbance in ethanol at 281 nm = 76.1; Melting point, 261.6 degrees C; IR spectrum, exhibited the specific absorptions at 3345, 2867, 1720, 1499 and 1055 cm-1; thin-layer chromatography, 2 impurities were detected at 100 and 200 micrograms; high-performance liquid chromatography, total amount of impurities estimated to be less than 0.3%. Based on the above results, the raw material was authorized as Estrone Reference Standard (Control 021) of the National Institute of Health Sciences.

Chromatography, High Pressure Liquid↗

[Piperazinyl estrone, a new estrogen derivant, prevents bone loss in aged rats].

The purpose of this study was to determine the effects of piperazinyl estrone, a new estrogen derivative, on bone turnover, bone mass and uterine weight in female aged rats. Thirty-two Sprague-Dawley female rats at the age of 22 months were treated with vehicle or with piperazinyl estrone (P-E) at 0.5, 1 and 2 mg/kg/day, subcutaneous injection for 1 month. At the time of death, the uterine weight was measured and bone histomorphometric analysis of proximal tibial metaphyses (PTM) was performed in undecalcified sections. Compared with control, bone mass was increased in P-E groups. Dynamic data showed that bone resorption were decreased, but bone formation was not declined and bone mass was increased significantly in P-E (1 mg/kg day) group. There was no significant change in uterine weight. The findings of this study show that piperazinyl estrone at dosage of 1 mg/kg/d is most efficacious in preventing the bone losses in aged rats and has no side effect on uterus.

Aging↗

The effects of estrone (Ogen) on spinal bone density of postmenopausal women.

The effects of cyclical treatment with estrone sulfate (0.3, 0.625, or 1.25 mg), plus calcium carbonate, on spinal trabecular bone density were compared with placebo in 120 postmenopausal women in this 2-year, multicenter, double-blind study. While the placebo and 0.3-mg treatment groups lost bone density (-3.6% and -5.1%), the 0.625- and 1.25-mg treatment groups experienced no significant change from baseline at 24 months (-0.8% and +0.7%). The 1.25-mg treatment group was significantly different from the placebo group at 12, 18, and 24 months. Although the 0.625-mg treatment group was significantly different from the placebo group only at 18 months, the data suggest that 0.625 and 1.25 mg of estrone sulfate had different effects than placebo and 0.3 mg of estrone sulfate and, given with supplemental calcium, are effective doses for the prevention of spinal bone loss.

Bone Density↗

Effect of treatment with 4-hydroxyandrostenedione on the peripheral conversion of androstenedione to estrone and in vitro tumor aromatase activity in postmenopausal women with breast cancer.

The effect of treatment with the aromatase inhibitor, 4-hydroxyandrostenedione (4-OHA) on the peripheral conversion of androstenedione to estrone has been examined in eight postmenopausal women with advanced breast cancer. Before treatment conversion of androstenedione to estrone ([p]AEIBB) ranged from 0.81 to 3.7% and was almost completely inhibited after treatment with 4-OHA (two doses of 500 mg i.m. with an interval of 12 days between doses). Transfer constants were also measured by the urinary method ([p]AEIBU) for some subjects and decreased from 2.3 +/- 0.52% to 0.24 +/- 0.11% after treatment, a mean reduction of 90%. Mean plasma concentration of estradiol (37.4 +/- 16.6 pmol/liter) and estrone (99.0 +/- 32.2 pmol/liter) decreased significantly (P less than 0.01) to 15.7 +/- 4.6 pmol/liter and 52.4 +/- 8.9 pmol/liter, respectively, after treatment. Aromatase and DNA polymerase alpha (a marker of cell proliferation) activities were measured in seven samples of breast tumor tissue obtained before and after treatment. For three samples there was a marked (67 +/- 17%) decrease in tumor aromatase activity after treatment, for two, little change occurred, while tumor aromatase activity in the other two samples appeared to be resistant to the effect of 4-OHA. The correlation between tumor aromatase and DNA polymerase alpha activities (r = 0.45) failed to reach a significant level.

Aged↗

Obese men have elevated plasma levels of estrone sulfate.

The 24 h mean plasma concentrations of estrone sulfate (ES) were measured in 27 healthy obese and nonobese men (BMI: 21.2-89.5). Plasma levels of ES were found to be elevated in obese men, with ES values significantly correlated to the level of obesity (r = 0.60; P less than 0.001). Thus, an increase in plasma ES concentration (from 524 to 1115 pg/ml), compared to the less than 40 percent increases previously found for estrone and estradiol. Because ES is normally present at an approximately tenfold greater concentration than either estrone or estradiol in men, it may serve as a more easily measurable indicator of adipose tissue aromatization of androstenedione.

Adipose Tissue↗

[Changes in estrone and estradiol synthesis in fetal and newborn rats].

The question was approached whether estradiol synthesis by the rat ovary gained in importance with age relatively to estrone synthesis, which predominated largely in the 20-day-old fetus. Three stages were investigated, i.e. fetal stage 21 days and stages 2 and 7 days after birth. Ovaries were cultured in vitro in the presence of various radioactive androgens, and the conversion percentages into estrone (E1) and estradiol (E2) were determined by double isotopic dilution combined with recrystallization to constant specific activity. Insignificant in the 21-day-old fetus (E1/E2 ratio = 40), estradiol synthesis increased relatively to estrone synthesis in the 2-day-old neonate and still more at the stage of 7 days (E1/E2 ratio = 3). FSH had no effect on estrogen synthesis at the 3 stages investigated.

Animals↗

[Characterization, in the guinea pig, of a hepatic cytosol protein binding dehydroepiandrosterone sulfate and estrone sulfate].

A protein which binds dehydroepiandrosterone sulfate and estrone sulfate was detected in the cytosolic fraction of female Guinea-pig liver. It is characterized by a molecular mass of 14,400 Da, its affinity for DHEA sulfate (KD = 8.8 microM) and estrone sulfate (KD = 8.5 microM), and its lack of affinity for free steroids such as dehydroepiandrosterone or estrone. It is eluted by gel filtration on Sephadex G-50 simultaneously with the inhibitor of microsomal DHEA sulfatase recently described by some of us. This protein could be implicated in the intracellular transport or in the metabolism of sulfated steroids.

Animals↗

Monitoring ovulation and implantation in the cynomolgus macaque (Macaca fascicularis) through evaluations of urinary estrone conjugates and progesterone metabolites: a technique for the routine evaluation of reproductive parameters.

Investigations were undertaken to determine the applicability of recently reported specific radioimmunoassays for urinary estrone conjugates and progesterone metabolites for monitoring ovarian function in the cynomolgus macaque (Macaca fasciularis) and other macaque species. Mean estrone conjugate measurements appear to accurately reflect the preovulatory estrogen peak in both conceptive (n = 5) and nonconceptive (n = 6) cycles, as well as to indicate early pregnancy through increases which are significantly elevated by Day + 15 (p less than 0.049) post estrone conjugates peak. The mean luteal phase levels of these progesterone metabolites are significantly elevated by Day + 14 (p less than 0.012) in conceptive cycles when compared to the mean values for nonconceptive cycles.

Animals↗

[Effect of estrone on formation of the focus of heterotopic hematopoiesis].

The effect of estrone injections on the heterotopic bone marrow organ formation was studied in (C57Bl X CBA)F1 mice by bone marrow shaft transplantation under the kidney capsule. Estrone injections resulted in femur marrow fibrosis, the increase in the weight of femur and heterotopic organ ossicle, drastic reduction in heterotopic organ cellularity. Depression of hemopoiesis in ectopic organ cannot be attributed to mechanical displacement of hemopoietic cells because a newly formed bone cavity under the kidney capsule was not closed. Thus, estrone had a detrimental effect on the creation of microenvironment in the heterotopic organ.

Animals↗

Hepatic morphine and estrone glucuronyltransferase activity and morphine biliary excretion in the isolated perfused rat liver. Effect of pregnancy and estradiol-17 beta treatment.

Hepatic microsomal estrone and morphine glucuronyltransferase activity and the biliary excretion of morphine in the isolated perfused liver were examined in nonpregnant, pregnant (19-21 days of gestation), and estradiol-17 beta-treated (E2; 1.0 mg/kg/day sc for 14 days) rats. Pregnancy decreased estrone and morphine glucuronyltransferase activity 20%, whereas E2 treatment increased activity 50%. Treatment of nonpregnant and pregnant rats with 2,3,7,8-tetrachlorodibenzo-p-dioxin (3 micrograms/kg po) increased estrone glucuronyltransferase activity 1.3- and 2.8-fold respectively, but such treatment had no effect in E2-treated rats. In the isolated perfused liver, E2 treatment, but not pregnancy, decreased the biliary excretion of morphine 3-glucuronide. Bile flow (microliter/min/g of liver) was slightly decreased by pregnancy but not by E2 treatment. Maximal bile/perfusate concentration ratios of morphine glucuronide were 175, 325, and 90 in livers from nonpregnant, pregnant, and E2-treated rats, respectively.

Animals↗

Estradiol, estrone, and gonadotropin levels after use of vaginal estradiol.

The vaginal absorption of 0.5-mg tablets of micronized estradiol was evaluated in postmenopausal women. In a single-dose study, one hour after insertion, a 5.3-fold rise in mean serum estradiol levels and 1.5-fold rise in mean serum estrone levels were observed. Mean levels of luteinizing hormone and follicle-stimulating hormone were significantly depressed. In a three-week alternate-day regimen, mean serum levels of estradiol were consistently two to three times greater than those of estrone 12 hours after insertion. Vaginal absorption of micronized estradiol tablets into the systemic circulation was found to be rapid and efficient. The vaginal route was acceptable and well tolerated by patients. In addition, the major conversion of estradiol to estrone that follows oral or sublingual administration was reduced. The vagina may be a preferred alternate route for estrogen replacement therapy in selected patients.

Drug Administration Schedule↗

[Conformation of estrone and its derivatives from crystallographic data. Roentgenostructural analysis of 3-deoxyestrone].

The conformational analysis of estrone and its derivatives has been performed using the crystallographic data. It is shown that the estrone backbone may have four different conformers due to the conformational flexibility of the B- and D-rings. The correlation plots describing the conformations of the B- and D-rings are given. There is no apparent correlation between the nature of the substituent at C (3) and the overall conformation of the estrone backbone. An X-ray analysis of 3-deoxyestrone has also been undertaken. The crystal data are: space group P212121, Z = 4(C18H22O), a 25,240 (3), b 8,049 (2), c 7,002 (3) A, V 1423 A3, dcalc 1,19 g X cm.-3. The final reliability factors are: R 3,71% and Rw 4,23% for 1501 observed reflections measured on an automatic diffractometer.

Crystallography↗

Interrelation between tumor cell proliferation and 17-fluoresceinated estrone binding following primary tumor removal, radiation, cyclophosphamide, or tamoxifen.

The proportion of single intact viable mouse mammary tumor cells containing estrogen receptor (ER) as determined by 17-fluoresceinated estrone binding and the proportion labeled with [3H]thymidine (LI) have been assessed in the same cell population after either primary tumor removal, radiation, cyclophosphamide, or tamoxifen administration. Subsequent to tumor removal, the increase in LI occurring in a cell population from a residual tumor focus was associated with a concomitant decrease in the proportion of cells demonstrating 17-fluoresceinated estrone binding (fluorescence). As the level of LI in the tumor focus returned to that observed prior to tumor removal, the proportion of ER-containing cells simultaneously reverted to its original value. Following cyclophosphamide administration, there was a decrease in tumor LI and a concomitant elevation in the proportion of fluorescent cells which were dose related. The prolonged depression in LI following radiation was accompanied by a sustained increase in the proportion of ER-containing cells. Thus, the change in ER-containing cells was related to the alteration of the proliferating cell population by the various therapies. The findings support the thesis that fewer cells in the growth fraction of the tumor studied contain ER than in the nonproliferating cell pool. Following tamoxifen administration, a decrease occurred in the proportion of fluorescing cells due to competitive binding. There was no alteration in LI. This observation is not in conflict with the thesis that there is a correlation between ER and LI since the mechanism for reduction in detectable ER is different. These studies provide additional support to the credibility of the use of 17-fluoresceinated estrone binding for the determination of ER in individual tumor cells. They also indicate the usefulness of the method for obtaining biological information regarding tumor ER which cannot be obtained with the use of conventional biochemical analyses.

Animals↗