Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0338671 (Steroids)
 9,479 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An inhibitor of microsomal dehydroepiandrosterone sulfatase was found in the soluble fraction of non-pregnant guinea pig liver. The extent of inhibitory effect was dependent on the concentration of soluble proteins. The inhibitor was partly purified by gel permeation and hydroxylapatite chromatography with a purification factor of 16.6. The soluble inhibitor was non-dialyzable, not destroyed by RNase or DNase digestion but totally destroyed by pronase digestion. The inhibitor is a soluble protein with a molecular weight of approximately 17,000 (determined by gel permeation chromatography). Inhibition of microsomal dehydroepiandrosterone sulfatase by the soluble inhibitor is a non-competitive inhibition. From this present finding the question arises whether the inhibitor could be involved in the regulation of the hydrolysis of dehydroepiandrosterone sulfate in the guinea pig liver.
Steroids 1986 Jun
PMID:A dehydroepiandrosterone sulfatase inhibitory activity in soluble proteins of guinea pig liver. 303 97

Nuclear and cytoplasmic binding sites for estradiol (E2-17 beta) in granulosa cells of immature rats were characterized. These binding sites for estrogen were high affinity, low capacity with an affinity constant (Kd) of 1.9 X 10(-10)M (binding capacity, Ro = 80 pM) for nuclear sites and a Kd = 3.5 X 10(-10) M (Ro = 45 pM) for cytosol sites. Binding was specific for biologically active estrogens. The estrogen receptor in granulosa cells is a protein and heat-labile as treatment with protease or pre-incubation at 37 degrees C for 1 h significantly diminished binding. RNase and DNase had no effect on estrogen binding. Sedimentation coefficients for nuclear and cytosol binding components were 5S and 8S respectively, similar to values obtained with uteri. Finally, translocation was demonstrated after a s.c. injection of E2-17 beta. Forty-five minutes post-injection, cytosol binding sites for estradiol were depleted concomitant with accumulation of nuclear binding sites. We concluded that granulosa cells of immature rats have binding sites specific for estradiol which have characteristics similar to the classical estrogen receptor in uteri.
Steroids 1983 Oct
PMID:Identification of estrogen receptors in granulosa cells of immature rats. 667 47

Progression to hormone-refractory disease is a common outcome of human prostate cancer. In this study, we have investigated the basis of androgen insensitivity in the human prostate cancer cell line, PC-3, which was derived from a bone metastasis of a hormone-refractory prostate cancer. PC-3 cells with virtually undetectable (PC-3AR-) or low (PC-3AR+) levels of androgen receptor (AR) RNA expression were examined. RNase protection assays demonstrated that the level of AR RNA in PC-3AR+ cells was similar to that in a normal androgen-responsive genital skin fibroblast cell strain. Quantitative immunocytochemical staining of AR in PC-3AR+ cells using antibodies directed against the amino and carboxyl termini of the receptor revealed staining in 30% of cells with either antibody. Furthermore, the level of AR staining in PC-3AR+ cells was higher than in the androgen-responsive breast cancer cell lines ZR-75-1, T47-D, and MCF-7. Despite the expression of AR RNA and protein, PC-3AR+ cell proliferation was unaffected by the presence of 0.1-10 nM mibolerone. Scatchard analysis demonstrated a complete absence of specific [3H]dihydrotestosterone ([3H]DHT) binding to PC-3AR+ cytosolic extracts, which could not be explained by structural alterations in the AR gene. The sizes of individual AR exons amplified from genomic DNA derived from PC-3AR+ cells were identical to those amplified from normal human cells. Furthermore, sequence analysis did not reveal a mutation in the DNA- or hormone-binding domains of the AR gene in PC-3AR+ cells.(ABSTRACT TRUNCATED AT 250 WORDS)
Steroids 1995 Jan
PMID:Evidence for a novel mechanism of androgen resistance in the human prostate cancer cell line, PC-3. 779 9

The LNCaP-Fast Growing Colony (FGC) human prostate cancer cell line proliferates in response to the addition of dihydrotestosterone (DHT) 10(-10)-10(-8) M in charcoal-stripped serum-supplemented media. LNCaP-FGC cells will not attach or proliferate in serum-free conditions. LNCaP-FGC stock cultures were maintained in medium supplemented with 10% FBS and added DHT (10(-9) M) for > 25 passages (6 months). The resultant subline was designated as LNCaP-ss (supersensitive) because of its ability to attach in serum-free medium and to proliferate in response to very low levels of DHT. LNCaP-ss cells were grown in serum-free medium and proliferation assessed after 2, 3, 5, and 7 days' treatment with DHT. Significant enhancement of growth was demonstrated after 7 days' treatment with DHT over a wide range of concentrations (DHT 10(-15)-10(-7) M) with maximal stimulation (3 x control, p < .001) noted with DHT 10(-14) M. Changing the medium during the course of the experiment decreased, but did not eliminate, the DHT-induced cellular proliferation. Scatchard analysis of binding studies with LNCaP-ss cells revealed that both the Kd for the androgen receptor (AR) and the number of AR sites/cell were similar to the corresponding values reported for the parental line. AR mRNA levels in LNCaP-ss cells, as measured by RNase protection assay, were significantly down-regulated by 7 days' treatment with DHT 10(-15), 10(-13), and 10(-9) M.(ABSTRACT TRUNCATED AT 250 WORDS)
Steroids 1993 Sep
PMID:Enhanced androgen sensitivity in serum-free medium of a subline of the LNCaP human prostate cancer cell line. 823 30

Steroids and neuropeptides interact in the central nervous system (CNS) to regulate reproductive function and behavior. The preoptic regulatory factors, PORF-1 and PORF-2, are unique neuropeptides for which roles in gender-related brain development and function have been proposed. PORF-1 and PORF-2 expression in rat brain are age, region and gender dependent, and castration or hypophysectomy alter the metabolism of the PORF-1 and PORF-2 mRNAs in male rat brain and testes. If these two peptides have a role in gender-dependent brain function, then gonadal steroids might well affect their expression. The present study was designed to investigate the response of the PORF-1 and PORF-2 mRNAs to sex steroids in the female rat brain and to compare this response to that of two peptides whose roles in the neuroendocrinology of reproduction are well established, gonadotropin-releasing hormone (GnRH) and neuropeptide Y (NPY). Rats were ovariectomized and treated with placebo, estradiol (E2), progesterone (P4) or a combination of the two (E2/P4) and NPY, PORF-2, GnRH and PORF-1 mRNAs were quantified by nuclease protection assays. PORF-1, PORF-2 and GnRH mRNAs were also measured in intact rats during estrus and proestrus. Responses were compared in the preoptic anterior hypothalamus (POA), medial basal hypothalamus (MBH), cerebral cortex (CC) and hippocampus (HIPP). Expression of PORF-1 and PORF-2 was also confirmed in the female rat hypothalamus by in situ hybridization analysis. PORF-1 and PORF-2 mRNAs were detected in the adult female rat brain by both in situ hybridization and ribonuclease protection analyses. In situ hybridization analysis demonstrated that PORF-1 and PORF-2 mRNAs are expressed in hypothalamic neurons. RNase protection analysis showed that PORF-1, PORF-2 and NPY mRNAs were present in all four brain regions examined while GnRH expression was detected only in the MBH and POA. Estradiol alone upregulated expression of the PORF-1 and PORF-2 mRNAs in the ovariectomized rat in the POA and HIPP, and of NPY mRNA in the MBH and HIPP. Progesterone alone had a stimulatory effect on NPY mRNA in the MBH and HIPP. Treatment with a combination of E2/P4 downregulated PORF-2 mRNA in the POA as well as PORF-1, PORF-2 and NPY mRNAs in the CC. In contrast, E2/P4 upregulated the PORF-2 and NPY mRNAs in the HIPP and NPY mRNA in the MBH. In the cycling rat, PORF-1 mRNA levels were higher during proestrus than estrus in both the MBH and POA, while PORF-2 mRNA levels did not change. In contrast GnRH mRNA was lower in the POA and higher in the MBH during proestrus compared with estrus. Thus, intrinsic factors, most likely both ovarian and neuroendocrine, regulate PORF-1 and GnRH expression in the intact cycling rat CNS in a region-dependent manner. In the ovariectomized rat, PORF-1, PORF-2, NPY and GnRH mRNAs all respond in a region-specific manner to sex steroid treatment. These data support the role of PORF-1 and PORF-2 in gender-dependent brain function in the adult female rat.
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PMID:Differential gene expression response to gonadal hormones by preoptic regulatory factors-1 and -2 in the female rat brain. 1008 51