Expression of Estrogen Sulfotransferase 1E1 and Steroid Sulfatase in Breast Cancer: A Immunohistochemical Study

It is known that the steroid sulfatase (STS) and the estrogen sulfotransferase (EST1E1) are commonly expressed in human breast carcinomas. STS and EST1E1 combined action could maintain the equilibrium between sulfated (inactive) and unconjugated (active) estrogens, which might have effects on development of hormone dependent breast cancer.

We studied the expression of the STS and EST1E1 in 88 breast carcinomas and 57 adjacent non-malignant tissues by immunohistochemistry. The results were correlated with the tumor expression of estrogen receptor α (ER-α) and β (ER-β), progesterone receptor A (PR-A) and B (PR-B) and the proliferation marker CDC47, the tumoral type and stage and the age at surgery.

STS expression was higher in carcinoma specimens than in adjacent normal tissues, although not to a significant level (p = 0.064) and it was positively associated with CDC47 expression (p < 0.05). These observations support the hypothesis that STS is overexpressed in breast cancer and associated with a worse prognosis.

EST1E1 was observed for the first time in the nuclei of epithelial and tumoral cells. Tumor expression of EST1E1 was positively correlated with ER-β (p < 0.01) and PR-B (p < 0.05), two steroid receptors already associated with an improve prognosis for breast cancer.

Controlling the STS overexpression in carcinomas could be a way to inhibit cancer growth. The significance of the association between EST1E1 and ER-β or PR-B should be further studied since these two receptors are transcription activators and may regulate the expression of protective enzymes like EST1E1.

Energy spectrum of cosmic-ray electrons at TeV energies

The very large collection area of ground-based gamma-ray telescopes gives them a substantial advantage over balloon or satellite based instruments in the detection of very-high-energy (>600 GeV) cosmic-ray electrons. Here we present the electron spectrum derived from data taken with the High Energy Stereoscopic System (H.E.S.S.) of imaging atmospheric Cherenkov telescopes. In this measurement, the first of this type, we are able to extend the measurement of the electron spectrum beyond the range accessible to direct measurements. We find evidence for a substantial steepening in the energy spectrum above 600 GeV compared to lower energies.

Expression of 17beta-hydroxysteroid dehydrogenase type 2 and type 5 in breast cancer and adjacent non-malignant tissue: a correlation to clinicopathological parameters

Estrogens play an important role in the development and progression of breast cancer. 17beta-Hydroxysteroid dehydrogenase (17beta-HSD) type 2 and type 5 are involved in sex steroid metabolism. 17beta-HSD type 2 converts estradiol to estrone while 17beta-HSD type 5 converts androstenedione to testosterone. Using immunocytochemistry, we have studied the expression of 17beta-HSD type 2 and type 5 in 50 specimens of breast carcinoma and adjacent non-malignant tissues. The results were correlated with the estrogen receptor alpha (ERalpha) and beta (ERbeta), progesterone receptor A (PRA) and B (PRB), androgen receptor and CDC47 and with the tumor stage, tumor size, nodal status and menopausal status. 17beta-HSD type 2 was expressed in 20% and 17beta-HSD type 5 in 56% of breast cancer specimens. In adjacent normal tissues, both enzymes were highly expressed in almost all the patients. No significant association could be found between the expression of 17beta-HSD type 2 and 17beta-HSD type 5 and between the expression of each enzyme and the clinicopathological parameters studied. The decrease in 17beta-HSD type 2 and 17beta-HSD type 5 expressions in breast cancer may play a predominant role in the development and/or progression of the cancer by modifying the intratumoral levels of estrogens and androgens.

Limits on an energy dependence of the speed of light from a flare of the active galaxy PKS 2155-304

In the past few decades, several models have predicted an energy dependence of the speed of light in the context of quantum gravity. For cosmological sources such as active galaxies, this minuscule effect can add up to measurable photon-energy dependent time lags. In this Letter a search for such time lags during the High Energy Stereoscopic System observations of the exceptional very high energy flare of the active galaxy PKS 2155-304 on 28 July 2006 is presented. Since no significant time lag is found, lower limits on the energy scale of speed of light modifications are derived.

Chronic administration of dehydroepiandrosterone (DHEA) to female monkey and rat has no effect on mammary gland histology

Dehydroepiandrosterone (DHEA), the major steroid precursor of androgens and estrogens produced in peripheral tissues in primates, has been shown to exert chemopreventive effect on the development of carcinogen-induced rat mammary tumors. Since little is known on the effect of DHEA administration on mammary gland physiology and histology, we have studied the effect of long-term administration of DHEA to normal female monkey and rat on mammary gland histology as well as on serum DHEA, DHEA sulphate (DHEA-S), testosterone and estradiol levels. In monkeys, DHEA treatment (2 or 10 mg/(kg b.w.day)) induced a dose-related increase in serum DHEA and DHEA-S (above 20-fold) levels. At the highest dose of DHEA, serum testosterone levels were significantly increased (three- to fourfold), while serum estradiol concentration was not modified. DHEA treatment did not modify the histological characteristics of monkey mammary glands. In the rat, following DHEA administration (10 or 100 mg/(kg b.w.day)), a dose-related marked increase in serum DHEA and DHEA-S was observed. Serum testosterone was also increased in DHEA-treated animals, while no significant changes in serum estradiol levels were detected. As in the monkey, the histology of the female rat mammary gland remained unchanged following long-term treatment with any of the two doses of DHEA.

Oestrogenic regulation of pro-opiomelanocortin, neuropeptide Y and corticotrophin-releasing hormone mRNAs in mouse hypothalamus

It is well documented that oestrogen suppresses food intake by an action at the hypothalamic level. Using in situ hybridisation, we studied the effect of castration (CX) and short-term administration of oestradiol (E2) in CX female mice for three neuropeptides involved in feeding behaviour: two anorexigenic peptides, (i) the pro-opiomelanocortin (POMC)-derived peptide alpha-melanocyte-stimulating hormone and (ii) corticotrophin-releasing hormone (CRH), and the orexigenic peptide, (iii) neuropeptide Y (NPY). POMC-expressing neurones were mostly laterally located in the arcuate nucleus. POMC mRNA expression was decreased following CX and a single injection of E2 induced an increase in mRNA levels at 12- and 24-h time intervals. In the parvocellular area of the paraventricular nucleus, CRH mRNA levels were similarly decreased after CX and completely restored to normal levels at 12 and 24 h following E2 injection. On the other hand, the levels of NPY mRNA expressed in neurones located in the inner zone of the arcuate nucleus were increased by CX and decreased to the levels observed in intact animals by E2 injection (3-24 h). The present data suggest that oestrogen might exert an anorexigenic action by stimulating POMC and CRH mRNA expression and decreasing NPY mRNA expression in the hypothalamus.

Expression of sulfotransferase 1E1 in human prostate as studied by in situ hybridization and immunocytochemistry

BACKGROUND

Estrogen is recognized to play a role in the development and function of the prostate. Estrogen sulfotransferase (EST) 1E1 catalyzes the sulfoconjugation of estrogen and is thus involved in the metabolism of estrogen. We have recently shown that EST 1E1 is highly expressed in male mouse reproductive organs, including prostate. It appeared of interest to study the expression of EST 1E1 in human prostate.

METHODS

EST 1E1 mRNA and protein expression was evaluated in benign prostatic hyperplasia (BPH) using in situ hybridization and immunocytochemistry, respectively.

RESULTS

EST 1E1 mRNA and protein were found to be expressed in epithelial cells bordering alveola lumen (luminal cells) as well as stroma cells.

CONCLUSION

The enzyme EST may play a physiological role in regulating local estrogen levels in human prostate.

Localization and glucocorticoid regulation of 11β-hydroxysteroid dehydrogenase type 1 mRNA in the male mouse forebrain

The enzyme 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) converts the inactive 11-dehydrocorticosterone into the active glucocorticoid corticosterone. There is accumulating evidence indicating widespread expression of 11beta-HSD1 in the brain. However, there is little information about regulation of 11beta-HSD1 expression in this tissue. Using in situ hybridization involving use of 35S-labeled cRNA probe, we have studied the distribution of cells expressing 11beta-HSD1 mRNA in the male mouse forebrain as well as the effects of adrenalectomy (ADX) and acute administration of corticosterone (3 and 24 h) on 11beta-HSD1 mRNA levels. Cells expressing 11beta-HSD1 mRNA were mostly detected in the cerebral cortex, hippocampus, amygdala and medial preoptic area, with the highest expression in the cerebral cortex (retrosplenial granular area) and hippocampus (CA3 and granular layer of the gyrus dentatus). Seven days following ADX, 11beta-HSD mRNA levels were increased by 50% in the gyrus dentatus, by 100% in the CA3 area, and 105% in the cerebral cortex. Administration of corticosterone to ADX mice induced a significant decrease in mRNA, in both the hippocampus and cerebral cortex so that, at the 24 h time interval, the levels were similar to those observed in intact mice. These results clearly indicate that circulating corticosterone is downregulating the expression of 11beta-HSD1 mRNA in the two forebrain areas studied. This downregulation might contribute to maintain low intracellular corticosterone levels in central regions and then prevent the deleterious effects induced by high glucocorticoid levels.

Comparison of two wavelet-based tools for data mining of urban water networks time series

In this paper, two approaches to data mining of time series have been tested and compared. Both methods are based on the wavelet decomposition of data series and allow the localization of important characteristics of a time series in both the time and frequency domain. The first method is a common method based on the analysis of wavelet power spectra. The second approach is new to the applied field of urban water networks and provides a qualitative description of the data series based on the cubic spline wavelet decomposition of the data. It is shown that wavelet power spectra indicate important and basic characteristics of the data but fail to provide detailed information of the underlying phenomena. In contrast, the second method allows the extraction of more and more detailed information that is important in a context of process monitoring and diagnosis.

Fast Variability of Tera–Electron Volt γ Rays from the Radio Galaxy M87

The detection of fast variations of the tera-electron volt (TeV) (10(12) eV) gamma-ray flux, on time scales of days, from the nearby radio galaxy M87 is reported. These variations are about 10 times as fast as those observed in any other wave band and imply a very compact emission region with a dimension similar to the Schwarzschild radius of the central black hole. We thus can exclude several other sites and processes of the gamma-ray production. The observations confirm that TeV gamma rays are emitted by extragalactic sources other than blazars, where jets are not relativistically beamed toward the observer.

HESS observations of the galactic center region and their possible dark matter interpretation

The detection of gamma rays from the source HESS J1745-290 in the Galactic Center (GC) region with the High Energy Spectroscopic System (HESS) array of Cherenkov telescopes in 2004 is presented. After subtraction of the diffuse gamma-ray emission from the GC ridge, the source is compatible with a point source with spatial extent less than 1.2;{'}(stat) (95% C.L.). The measured energy spectrum above 160 GeV is compatible with a power law with photon index of 2.25+/-0.04(stat)+/-0.10(syst) and no significant flux variation is detected. It is finally found that the bulk of the very high energy emission must have non-dark-matter origin.

Expression of aromatase and 17beta-hydroxysteroid dehydrogenase types 1, 7 and 12 in breast cancer. An immunocytochemical study

It is known that there is a local biosynthesis of estradiol (E2) in breast carcinoma. The steroidogenic enzymes involved in E2 formation are aromatase which transforms testosterone into E2 and androstenedione into estrone (E1) and reductive 17beta-hydroxysteroid dehydrogenases (17beta-HSDs) which convert E1 into E2. Using immunocytochemistry, we have studied the expression of aromatase and the three reductive 17beta-HSDs 17beta-HSD types 1, 7 and 12 in 41 specimens of female human breast carcinoma and adjacent non-malignant tissues. These results were correlated with the estrogen receptor alpha (ERalpha) and beta (ERbeta), progesterone receptor, androgen receptor, CDC47 and c-erb B-2 expressions and with the tumor stages. Aromatase was found in 58%, 17beta-HSD type 7 in 47% and 17beta-HSD type 12 in 83% of the breast cancer specimens. The 17beta-HSD type 1 could be detected in only one tumor. A significant correlation was observed between the aromatase, 17beta-HSD type 7 and 17beta-HSD type 12 expression, as well as between each of the two enzymes 17beta-types 7 and 12 and the ERbeta expression. The expression of 17beta-HSD type 12 was significantly higher in breast carcinoma specimens than in normal tissue. There was also a significant association of CDC 47 expression with ERbeta, AR and 17beta-HSD type 12. The results indicate that aromatase, 17beta-HSD type 7 and 17beta-HSD type 12, but not 17beta-HSD type 1, are commonly expressed in human breast cancer. Moreover, the high expression of both 17beta-HSD type 12 and ERbeta in breast carcinoma cells may play a role in the development and/or progression of breast cancer.

Role of androgens and glucocorticoids in the regulation of diazepam-binding inhibitor mRNA levels in male mouse hypothalamus

In peripheral organs, gonadal and adrenal steroids regulate diazepam-binding inhibitor (DBI) mRNA expression. In order to further investigate the involvement of peripheral steroid hormones in the modulation of brain DBI mRNA expression, we studied by semiquantitative in situ hybridization the effect of adrenalectomy (ADX) and castration (CX) and short-term replacement therapy on DBI mRNA levels in the male mouse hypothalamus. Cells expressing DBI mRNA were mostly observed in the arcuate nucleus, the median eminence and the ependyma bordering the third ventricle. In the median eminence and the ependyma bordering the third ventricule, the DBI gene expression was decreased in ADX rats and a single injection of corticosterone to ADX rats induced a significant increase in DBI gene expression at 3 and 12 h time intervals without completely restoring the basal DBI mRNA expression observed in intact mice. In the arcuate nucleus, ADX and corticosterone administration did not modify DBI mRNA expression. CX down-regulated DBI gene expression in the ependyma bordering the third ventricle. The administration of dihydrotestosterone (3-24 h) completely reversed the inhibitory effect of CX. In the median eminence and arcuate nucleus, neither CX or dihydrotestosterone administration modified DBI mRNA levels. These results suggest that the effects of glucocorticoids on the hypothalamo-pituitary-adrenocortical axis and androgens on the hypothalamo-pituitary-gonadal axis are mediated by DBI.

A low level of extragalactic background light as revealed by γ-rays from blazars

The diffuse extragalactic background light consists of the sum of the starlight emitted by galaxies through the history of the Universe, and it could also have an important contribution from the 'first stars', which may have formed before galaxy formation began. Direct measurements are difficult and not yet conclusive, owing to the large uncertainties caused by the bright foreground emission associated with zodiacal light. An alternative approach is to study the absorption features imprinted on the gamma-ray spectra of distant extragalactic objects by interactions of those photons with the background light photons. Here we report the discovery of gamma-ray emission from the blazars H 2356 - 309 and 1ES 1101 - 232, at redshifts z = 0.165 and z = 0.186, respectively. Their unexpectedly hard spectra provide an upper limit on the background light at optical/near-infrared wavelengths that appears to be very close to the lower limit given by the integrated light of resolved galaxies. The background flux at these wavelengths accordingly seems to be strongly dominated by the direct starlight from galaxies, thus excluding a large contribution from other sources-in particular from the first stars formed. This result also indicates that intergalactic space is more transparent to gamma-rays than previously thought.

Discovery of very-high-energy γ-rays from the Galactic Centre ridge

The source of Galactic cosmic rays (with energies up to 10(15) eV) remains unclear, although it is widely believed that they originate in the shock waves of expanding supernova remnants. At present the best way to investigate their acceleration and propagation is by observing the gamma-rays produced when cosmic rays interact with interstellar gas. Here we report observations of an extended region of very-high-energy (> 10(11) eV) gamma-ray emission correlated spatially with a complex of giant molecular clouds in the central 200 parsecs of the Milky Way. The hardness of the gamma-ray spectrum and the conditions in those molecular clouds indicate that the cosmic rays giving rise to the gamma-rays are likely to be protons and nuclei rather than electrons. The energy associated with the cosmic rays could have come from a single supernova explosion around 10(4) years ago.

In vivo action of a new octadecaneuropeptide antagonist on neuropeptide Y and corticotropin-releasing hormone mRNA levels in rat

It has been reported that several of the effects induced by an octadecaneuropeptide (ODN), derived from an 86-amino-acid polypeptide termed diazepam-binding inhibitor, could be mediated by activation of a metabotropic receptor. In order to investigate the role and mechanism of action of ODN in the regulation of corticotropin-releasing factor (CRH) and neuropeptide Y (NPY) expression in the paraventricular nucleus and arcuate nucleus, respectively, we studied the effects of the acute intracerebroventricular administration of ODN (2 microg/rat) and the ODN antagonist to metabotropic receptor, cyclo(1-8)[Dleu5]OP (20 microg/rat), on the gene expression of the two neuropeptides in castrated male rat. ODN administration resulted in a 45% increase in CRH mRNA expression, an effect which was reversed by cyclo(1-8)[Dleu5]OP. When cyclo(1-8)[Dleu5]OP was administered alone, it induced a 19% decrease in CRH mRNA levels. ODN administration induced a 17% decrease in NPY mRNA expression while cyclo(1-8)[Dleu5]OP increased by 21% the hybridization signal. The administration of both ODN and ODN antagonist completely abolished the depressing effect of ODN on NPY mRNA. These data suggest that the effects of ODN on CRH and NPY mRNA might be mediated by interaction with metabotropic receptors. Moreover, since cyclo(1-8)[Dleu5]OP can by itself influence the expression of two peptide mRNAs, it might be suggested that ODN is exerting a tonic influence on NPY and CRH neurons.

Is dehydroepiandrosterone a hormone?

Dehydroepiandrosterone (DHEA) is not a hormone but it is a very important prohormone secreted in large amounts by the adrenals in humans and other primates, but not in lower species. It is secreted in larger quantities than cortisol and is present in the blood at concentrations only second to cholesterol. All the enzymes required to transform DHEA into androgens and/or estrogens are expressed in a cell-specific manner in a large series of peripheral target tissues, thus permitting all androgen-sensitive and estrogen-sensitive tissues to make locally and control the intracellular levels of sex steroids according to local needs. This new field of endocrinology has been called intracrinology. In women, after menopause, all estrogens and almost all androgens are made locally in peripheral tissues from DHEA which indirectly exerts effects, among others, on bone formation, adiposity, muscle, insulin and glucose metabolism, skin, libido and well-being. In men, where the secretion of androgens by the testicles continues for life, the contribution of DHEA to androgens has been best evaluated in the prostate where about 50% of androgens are made locally from DHEA. Such knowledge has led to the development of combined androgen blockade (CAB), a treatment which adds a pure anti-androgen to medical (GnRH agonist) or surgical castration in order to block the access of the androgens made locally to the androgen receptor. In fact, CAB has been the first treatment demonstrated to prolong life in advanced prostate cancer while recent data indicate that it can permit long-term control and probably cure in at least 90% of cases of localized prostate cancer. The new field of intracrinology or local formation of sex steroids from DHEA in target tissues has permitted major advances in the treatment of the two most frequent cancers, namely breast and prostate cancer, while its potential use as a physiological HRT could well provide a physiological balance of androgens and estrogens, thus offering exciting possibilities for women's health at menopause.

A new recombined double low restorer line for the Ogu-INRA cms in rapeseed (Brassica napus L.)

A major objective of breeders using the Ogu-INRA cytoplasmic male sterility (cms) system in rapeseed (Brassica napus L.) is to obtain double low restorer lines with a shorter introgression and a good agronomic value. The development of low glucosinolate content (low GC) restorer lines often occurs through the deletion of a part of the introgression. One of these lines has lost the radish Pgi-2 allele expression, without recovering that of the rapeseed Pgi-2 allele. This line shows a defect in the meiotic transmission of the restorer gene Rfo and a very poor agronomic value. We initiated a programme to force non-spontaneous recombination between this Rfo-carrying introgression and the rapeseed homologous chromosome from a low GC B. napus line. Gamma ray irradiation was used to induce chromosome breakage just prior meiosis aiming at just such a recombination. Low GC cms plants were crossed with the pollen of irradiated plants that were heterozygous for this introgression. The F(2) families were scored for their vigour, transmission rate of Rfo and female fertility. One family of plants, R2000, showed an improved behaviour for these three traits. This family presented a unique combination of molecular markers when compared to other rapeseed restorers analysed, which suggests that the recombination event allowed the recovery of B. oleracea genetic information that was originally replaced by the radish introgression in the original restorers. This resulted in a duplicated region (originating from radish and B. oleracea) on the chromosome carrying the introgression in the R2000 family.

Discovery of Very High Energy Gamma Rays Associated with an X-ray Binary

X-ray binaries are composed of a normal star in orbit around a neutron star or stellar-mass black hole. Radio and x-ray observations have led to the presumption that some x-ray binaries called microquasars behave as scaled-down active galactic nuclei. Microquasars have resolved radio emission that is thought to arise from a relativistic outflow akin to active galactic nuclei jets, in which particles can be accelerated to large energies. Very high energy gamma-rays produced by the interactions of these particles have been observed from several active galactic nuclei. Using the High Energy Stereoscopic System, we find evidence for gamma-ray emission of >100 gigaelectron volts from a candidate microquasar, LS 5039, showing that particles are also accelerated to very high energies in these systems.

Localization of type 5 17beta-hydroxysteroid dehydrogenase mRNA in mouse tissues as studied by in situ hybridization

The mouse enzyme type 5 17beta-hydroxysteroid dehydrogenase (17beta-HSD) catalyzes the conversion of androstenedione to testosterone and, to a lesser degree, the conversion of estrone to estradiol. In order to determine the exact sites of action of type 5 17beta-HSD, we studied the cellular localization of the mRNA of the enzyme in mouse tissues by using in situ hybridization. Specific hybridization signal was found in the liver, ovary, adrenal cortex, and kidney. In the liver of mice of both sexes, a strong signal was observed in all hepatocytes. In the ovary, specific labeling was detected in the granulosa and theca interna cells in growing follicles and in luteal cells. In the female adrenal cortex, intense labeling was restricted to the zona reticularis, whereas no type 5 17beta-HSD mRNA expression could be found in the male adrenal cortex. In the kidney of mice of both sexes, type 5 17beta-HSD mRNA was expressed in epithelial cells in both the proximal and distal convoluted tubules. The data indicate that androgens and estrogens are formed via the action of type 5 17beta-HSD in specific cell types in the liver, ovary, adrenal cortex, and kidney.

A new population of very high energy gamma-ray sources in the Milky Way

Very high energy gamma-rays probe the long-standing mystery of the origin of cosmic rays. Produced in the interactions of accelerated particles in astrophysical objects, they can be used to image cosmic particle accelerators. A first sensitive survey of the inner part of the Milky Way with the High Energy Stereoscopic System (HESS) reveals a population of eight previously unknown firmly detected sources of very high energy gamma-rays. At least two have no known radio or x-ray counterpart and may be representative of a new class of "dark" nucleonic cosmic ray sources.

Androgenic down-regulation of urotensin II precursor, urotensin II-related peptide precursor and androgen receptor mRNA in the mouse spinal cord

We had previously shown that in rat spinal cord motoneurons urotensin II (UII) precursor mRNA was down-regulated by androgens. Very recently, a gene encoding the precursor of a UII analog, termed UII-related peptide (URP), has been identified. Using in situ hybridization, we studied the localization of UII and URP precursor as well as androgen receptor (AR) mRNA in the male mouse thoracic spinal cord. We also evaluated the androgenic regulation of the two peptide precursor and AR mRNA expression in the ventral horn of the mouse thoracic spinal cord. The results revealed that URP precursor mRNA was localized in motoneurons and that the vast majority of the motoneurons expressed both peptide precursor as well as AR mRNA. Seven-day castration induced an increase in UII and URP precursor and AR mRNA levels. Short term (3-24 h) administration of dihydrotestosterone to castrated animals restored the three protein mRNA levels to the levels observed in intact animals. These results suggest that in the ventral horn of the mouse spinal cord both UII and URP precursor and AR mRNA are expressed by the same neurons and that circulating androgens are exerting a down-regulation of the three protein mRNA expression, possibly by a direct action on motoneurons.