Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “SULFATASES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources
PubMed1994

Immunochemical characterization of feline and human N-acetylgalactosamine 4-sulfatase.

Maroteaux-Lamy syndrome (mucopolysaccharidosis type VI; MPS VI) is a disorder which results from a deficiency in the lysosomal associated enzyme N-acetylgalactosamine 4-sulfatase (4-sulfatase). A feline model of human MPS VI has previously been described and provides a system for the evaluation of enzyme replacement therapy protocols. As a preliminary study to human 4-sulfatase enzyme replacement therapy in feline we have compared the immunochemical properties of human and feline 4-sulfatase. By SDS-PAGE the molecular mass of purified feline and human 4-sulfatase were similar under both reducing and nonreducing conditions. There was, however, a detectable conformation difference between human and feline 4-sulfatase indicating some structural variation. Feline 4-sulfatase reacted weakly with a panel of monoclonal antibodies in an immunobinding assay (interacting with 4-sulfatase in free solution), but the same monoclonal antibodies reacted strongly with feline 4-sulfatase in an immunoquantification assay where the feline 4-sulfatase was bound to a polyclonal antibody (which presumably induces a conformation change in the feline 4-sulfatase to closer approximate the structure of human 4-sulfatase). A monoclonal antibody which selectively reacts with human 4-sulfatase has been used to develop an assay suitable for evaluating human 4-sulfatase enzyme replacement in cat tissues.

Animals↗
PubMed1985

Estrone- and dehydroepiandrosterone-sulfatase activities in human female epidermis.

Estrone (E1)-sulfatase and dehydroepiandrosterone (DHEA)-sulfatase activities were studied in human female epidermis. Skin specimens were obtained by abdominal or plantar biopsies. The apparent Michaelis-Menten constants for E1 and DHEA sulfatases were 35.2 microM and 8.7 microM, respectively. A substrate inhibition was only observed for DHEA sulfatase. Both sulfatases had an elevated temperature optimum (65 degrees C). The effect of inorganic salts was also tested. In normal epidermis, E1-sulfatase activity was constantly higher than DHEA-sulfatase activity, but no correlation between these activities was observed. On the other hand, E1- and DHEA-sulfatase activities were lower in plantar than in abdominal epidermis. In plantar epidermis of palmoplantar keratoderma, large variations in E1-sulfatase activity, but no significant variation in DHEA-sulfatase activity, were observed. In human epidermis, the findings were consistent with the existence of two different sulfatases: E1 sulfatase and DHEA sulfatase. It would also appear that sulfatase activities are not linked to the abnormal shedding of plantar stratum corneum in palmoplantar keratoderma.

Abdomen↗
PubMed1997

Structure of a human lysosomal sulfatase.

BACKGROUND: . Sulfatases catalyze the hydrolysis of sulfuric acid esters from a wide variety of substrates including glycosaminoglycans, glycolipids and steroids. There is sufficient common sequence similarity within the class of sulfatase enzymes to indicate that they have a common structure. Deficiencies of specific lysosomal sulfatases that are involved in the degradation of glycosamino-glycans lead to rare inherited clinical disorders termed mucopolysaccharidoses. In sufferers of multiple sulfatase deficiency, all sulfatases are inactive because an essential post-translational modification of a specific active-site cysteine residue to oxo-alanine does not occur. Studies of this disorder have contributed to location and characterization of the sulfatase active site. To understand the catalytic mechanism of sulfatases, and ultimately the determinants of their substrate specificities, we have determined the structure of N-acetylgalactosamine-4-sulfatase. RESULTS: . The crystal structure of the enzyme has been solved and refined at 2.5 resolution using data recorded at both 123K and 273K. The structure has two domains, the larger of which belongs to the alpha/beta class of proteins and contains the active site. The enzyme active site in the crystals contains several hitherto undescribed features. The active-site cysteine residue, Cys91, is found as the sulfate derivative of the aldehyde species, oxo-alanine. The sulfate is bound to a previously undetected metal ion, which we have identified as calcium. The structure of a vanadate-inhibited form of the enzyme has also been solved, and this structure shows that vanadate has replaced sulfate in the active site and that the vanadate is covalently linked to the protein. Preliminary data is presented for crystals soaked in the monosaccharide N-acetylgalactosamine, the structure of which forms a product complex of the enzyme. CONCLUSIONS: . The structure of N-acetylgalactosamine-4-sulfatase reveals that residues conserved amongst the sulfatase family are involved in stabilizing the calcium ion and the sulfate ester in the active site. This suggests an archetypal fold for the family of sulfatases. A catalytic role is proposed for the post-translationally modified highly conserved cysteine residue. Despite a lack of any previously detectable sequence similarity to any protein of known structure, the large sulfatase domain that contains the active site closely resembles that of alkaline phosphatase: the calcium ion in sulfatase superposes on one of the zinc ions in alkaline phosphatase and the sulfate ester of Cys91 superposes on the phosphate ion found in the active site of alkaline phosphatase.

Alkaline Phosphatase↗
PubMed1984

Estrone and dehydroepiandrosterone sulfatase activities in guinea-pig uterus and liver: estrogenic effect of estrone sulfate.

Estrone and dehydroepiandrosterone (DHA) sulfatase activities were studied in the uterus and liver of female guinea-pigs (albino variety). The two activities were found in particulates, with the highest specific activity in microsomes. The effects of pH, buffers, temperature and the non-competitive inhibition of DHA sulfate on estrone sulfatase provided arguments for the existence of two distinct sulfatases. However, acrylamide gel electrophoresis of the solubilized microsome sulfatases gave a single peak for the two activities. In the uterus, the apparent Km of estrone and DHA sulfatases were 26.4 and 15.6 microM. Solubilized microsomal estrone sulfatase was inhibited by unconjugated steroids. The apparent Km of estrone sulfatase in liver was 10.7 microM. Estrone and DHA sulfatase activities were consistently lower in liver than in uterus and no DHA sulfatase activity was detected in fetal liver. In the uterus, the same sulfatase activities were found in female fetuses, castrated or mature females. Estrone sulfatase was significantly increased in the uterus of pregnant females (60-65 days gestation). Estrone sulfate was injected in vivo into mature castrated females. A significant increase in uterine weight and in uterine progesterone receptors was observed. The cytosol progesterone receptors were characterized by their Kd (1.40 nM) and by sucrose density gradient. It is concluded that the variations of estrone sulfatase activity in target tissues like the uterus may control the intracellular levels of biologically active estrogens.

Animals↗
PubMed2002

Inhibition of steryl sulfatase activity in LNCaP human prostate cancer cells.

The enzyme steryl sulfatase may help support the growth of hormone-dependent tumors, including prostate cancers, by facilitating the conversion of circulating precursor steroids to active hormones. We sought to determine the presence of steryl sulfatase activity in the androgen-dependent human prostate cancer cell line LNCaP, and to determine if this activity was inhibited by known steryl sulfatase inhibitors. Intact LNCaP cultures had steryl sulfatase activity, as determined by conversion of [3H]estrone sulfate (E(1)S) to unconjugated steroids. The level of steryl sulfatase activity was relatively low (4.6 pmol/18 h/million cells) compared to MDA-MB-231 breast cancer cells (284.0 pmol/18 h/million cells). The observed activity in both cell lines was blocked by addition of 1 microM estrone sulfamate (EMATE), an active-site-directed, steroidal inhibitor of steryl sulfatase. Steryl sulfatase activity was also inhibited by Danazol, and by (p-O-sulfamoyl)-tetradecanoyl tyramine (C2-14), a non-steroidal inhibitor. Microsomes prepared from LNCaP cultures also showed steryl sulfatase activity, as determined by hydrolysis of [3H]E(1)S and [3H]dehydroepiandrosterone sulfate (DHEAS) to unconjugated forms. LNCaP and MDA-MB-231 microsomes both hydrolyzed E(1)S about two times faster than DHEAS. Hydrolysis of E(1)S in LNCaP and MDA-MB-231 microsomes was blocked by steryl sulfatase inhibitors with the following relative potencies: EMATE>C2-14>Danazol. These data demonstrate that LNCaP prostate cancer cells contain a steryl sulfatase with properties similar to that found in human breast cancer cells, and that the activity of this enzyme can be blocked by known steryl sulfatase inhibitors. Steryl sulfatase inhibitors may be useful as an adjuvant to androgen deprivation therapy for prostate cancer.

Arylsulfatases↗
PubMedDate not supplied

Development of potent non-estrogenic estrone sulfatase inhibitors.

Estrogen levels in breast tumors of post-menopausal women are as much as 10 times higher than estrogen levels in plasma, presumably due to in situ formation of estrogen. The major source of estrogen in breast cancer cells may be conversion of estrone sulfate to estrone by the enzyme estrone sulfatase. Thus, inhibitors of estrone sulfatase have potential for the treatment of estrogen-dependent breast cancers. Several steroidal agents have been developed that are potent estrone sulfatase inhibitors, most notably estrone-3-O-sulfamate. These compounds may have undesired actions, especially estrogenicity. Recently, non-steroidal estrone sulfatase inhibitors have been designed that avoid the problems associated with an active steroid nucleus; however, these have not achieved the potency of estrone-3-O sulfamate. We have designed and synthesized a series of compounds, 17 beta-(N-alkylcarbamoyl)-estra-1,3,5(10)-trien-3-O-sulfamates (6a-d) and 17 beta-(N-alkanoyl)-estra-1,3,5(10)-trien-3-O-sulfamates (11a-d) that combine the structural features of the steroidal estrone sulfatase inhibitors with a membrane insertion region that should increase the affinity for the sulfatase enzyme and decrease the estrogenicity of the steroid. We tested the compounds for estrone sulfatase inhibition by measuring estrone sulfatase activity in intact cultures of human breast cancer cells (MDA-MB-231). We tested for estrogenicity by measuring growth of estrogen-dependent MCF-7 human breast cancer cells. All of the test compounds (10 nM) substantially inhibited estrogen sulfatase activity of intact MDA-MB-231 cells. Dose-response analysis indicated an IC50 of approximately 0.5 nM for two of the compounds (6a and 11a). In the test for estrogenicity, estrone and estrone-3-O-sulfamate significantly stimulated MCF-7 cell growth. In contrast, neither the 17 beta-(N-alkylcarbamoyl)-estra-1,3,5,(10)-trien-3-O-sulfamates++ + nor the 17 beta-(N)-alkanoyl)-estra-1,3,5,(10)-trien-3-O-sulfamates stimulated growth of MCF-7 cells at a concentration of 1 microM, indicating that they are not estrogenic at levels 2000 times greater than their IC50 for estrone sulfatase. Our data indicate the utility of the new compounds for inhibition of breast cancer cell estrone sulfatase activity. Further, our data support the concept that estrone sulfatase inhibitors may be useful as therapeutic agents for estrogen-dependent breast cancers.

Breast Neoplasms↗
PubMedDate not supplied

Ichthyosis: the skin manifestation of multiple sulfatase deficiency.

Juvenile sulfatidosis (Austin type) or multiple sulfatase deficiency is an extremely rare autosomal recessive disorder affecting the activity of many sulfatases: arylsulfatase A, several mucopolysaccharide sulfatases, and steroid sulfatase. Certain aspects of the clinical phenotype can be attributed mainly to a deficiency of one specific sulfatase. Most patients develop metachromatic leukodystrophy caused by arylsulfatase A deficiency, dysostosis multiplex by mucopolysaccharide sulfatase deficiency, and ichthyotic skin by steroid sulfatase deficiency. We describe a 7-year-old boy with developmental delay from 7 months of age, progressive spastic quadriparesis, and coarse facial features. By 27 months of age, an ichthyotic rash had developed on the limbs, trunk, and scalp. A skin biopsy specimen revealed hyperkeratosis with a normal granular layer. The diagnosis of multiple sulfatase deficiency was demonstrated by measuring sulfatase activities in fresh leukocytes: there were large deficiencies of arylsulfatase A and B plus reduced arylsulfatase C. The ichthyosis associated with multiple sulfatase deficiency has an autosomal recessive inheritance, is caused by steroid sulfatase deficiency, and the scaling is sometimes milder than in X-linked recessive ichthyosis. This could reflect the residual activity of steroid sulfatase in some cases.

Child↗
PubMed2000

Cloning of a mucin-desulfating sulfatase gene from Prevotella strain RS2 and its expression using a Bacteroides recombinant system.

A gene encoding the mucin-desulfating sulfatase in Prevotella strain RS2 has been cloned, sequenced, and expressed in an active form. A 600-bp PCR product generated using primers designed from amino acid sequence data was used to isolate a 5,058-bp genomic DNA fragment containing the mucin-desulfating sulfatase gene. A 1,551-bp open reading frame encoding the sulfatase proprotein was identified, and the deduced 517-amino-acid protein minus its signal sequence corresponded well with the published mass of 58 kDa estimated by denaturing gel electrophoresis. The sulfatase sequence showed homology to aryl- and nonarylsulfatases with different substrate specificities from the sulfatases of other organisms. No sulfatase activity could be detected when the sulfatase gene was cloned into Escherichia coli expression vectors. However, cloning the gene into a Bacteroides expression vector did produce active sulfatase. This is the first mucin-desulfating sulfatase to be sequenced and expressed. A second open reading frame (1,257 bp) was identified immediately upstream from the sulfatase gene, coding in the opposite direction. Its sequence has close homology to iron-sulfur proteins that posttranslationally modify other sulfatases. By analogy, this protein is predicted to catalyze the modification of a serine group to a formylglycine group at the active center of the mucin-desulfating sulfatase, which is necessary for enzymatic activity.

Amino Acid Sequence↗
PubMed1983

Estrone and dehydroepiandrosterone sulfatase activities in normal and pathological human endometrium biopsies.

The properties of estrone (E1) and dehydroepiandrosterone (DHEA) sulfatase activities are reported. Endometrial biopsy specimens were obtained using a Novak curette. Cycle stage was assessed from histological dating of endometrium, plasma estradiol and progesterone levels, and patient history. Both sulfatases are membrane-bound enzymes. The optimum pHs in Tris-HCl buffer were 6.5 for E1 sulfatase and 7.3 for DHEA sulfatase. Lowest activities and different optimum pHs were obtained with imidazole, maleate, or acetate buffers. DHEA sulfatase is more sensitive to thermal inactivation than E1 sulfatase. From kinetic studies, apparent Km values of 3.1 microM for E1 sulfatase and 5.7 microM for DHEA sulfatase were calculated. Noncompetitive inhibition of E1 sulfatase by DHEA sulfate and of DHEA sulfatase by E1 sulfate were demonstrated. The effects of inorganic ions and unconjugated steroids were also tested. These results are consistent with two different activities hydrolyzing E1 or DHEA sulfates. Neither activity varies during normal menstrual cycles nor is not correlated to plasma progesterone or 17 beta-estradiol levels. An isolated increase in E1 sulfatase occurred in the proliferative phase of irregular menstrual cycles, postantibiotic-treated salpingitis, or hyperplastic endometrium.

Dehydroepiandrosterone↗
PubMed2000

Structure-activity relationships of 17alpha-derivatives of estradiol as inhibitors of steroid sulfatase.

The steroid sulfatase or steryl sulfatase is a microsomal enzyme widely distributed in human tissues that catalyzes the hydrolysis of sulfated 3-hydroxy steroids to the corresponding free active 3-hydroxy steroids. Since androgens and estrogens may be synthesized inside the cancerous cells starting from dehydroepiandrosterone sulfate (DHEAS) and estrone sulfate (E(1)S) available in blood circulation, the use of therapeutic agents that inhibit steroid sulfatase activity may be a rewarding approach to the treatment of androgeno-sensitive and estrogeno-sensitive diseases. In the present study, we report the chemical synthesis and biological evaluation of a new family of steroid sulfatase inhibitors. The inhibitors were designed by adding an alkyl, a phenyl, a benzyl, or a benzyl substituted at position 17alpha of estradiol (E(2)), a C18-steroid, and enzymatic assays were performed using the steroid sulfatase of homogenized JEG-3 cells or transfected in HEK-293 cells. We observed that a hydrophobic substituent induces powerful inhibition of steroid sulfatase while a hydrophilic one was weak. Although a hydrophobic group at the 17alpha-position increased the inhibitory activity, the steric factors contribute to the opposite effect. As exemplified by 17alpha-decyl-E(2) and 17alpha-dodecyl-E(2), a long flexible side chain prevents adequate fitting into the enzyme catalytic site, thus decreasing capacity to inhibit the steroid sulfatase activity. In the alkyl series, the best compromise between hydrophobicity and steric hindrance was obtained with the octyl group (IC(50) = 440 nM), but judicious branching of side chain could improve this further. Benzyl substituted derivatives of estradiol were better inhibitors than alkyl analogues. Among the series of 17alpha-(benzyl substituted)-E(2) derivatives studied, the 3'-bromobenzyl, 4'-tert-butylbenzyl, 4'-butylbenzyl, and 4'-benzyloxybenzyl groups provided the most potent inhibition of steroid sulfatase transformation of E(1)S into E(1) (IC(50) = 24, 28, 25, and 22 nM, respectively). As an example, the tert-butylbenzyl group increases the ability of the E(2) nucleus to inhibit the steroid sulfatase by 3000-fold, and it also inhibits similarly the steroid sulfatase transformations of both natural substrates, E(1)S and DHEAS. Interestingly, the newly reported family of steroid sulfatase inhibitors acts by a reversible mechanism of action that is different from the irreversible mechanism of the known inhibitor estrone sulfamate (EMATE).

Arylsulfatases↗
PubMed1991

Analysis of N-acetylgalactosamine-4-sulfatase protein and kinetics in mucopolysaccharidosis type VI patients.

A sensitive and specific, monoclonal antibody-based immunoquantification assay has facilitated determination of the N-acetylgalactosamine-4-sulfatase (4-sulfatase) protein content in cultured fibroblasts from normal controls and mucopolysaccharidosis type VI (MPS VI) patients. The assay enabled the quantification of 4-sulfatase protein by using a panel of seven monoclonal antibodies and has shown that fibroblasts from 16 MPS VI patients contained less than or equal to 5% of the level determined for normal controls. Fibroblasts from the most severely affected patients contained the lowest levels of 4-sulfatase protein, usually with few epitopes detected, while fibroblasts from mildly affected patients had higher levels of 4-sulfatase protein, with all seven epitopes detected. The pattern of epitope expression is proposed to reflect the conformational changes in the 4-sulfatase protein that arise from different mutations in the 4-sulfatase gene. Immunoquantification in combination with a specific and highly sensitive 4-sulfated trisaccharide-based assay of enzyme activity in these MPS VI patient fibroblasts enabled the determination of residual 4-sulfatase catalytic efficiency (kcat/Km). The capacity of fibroblasts to degrade substrate (catalytic capacity) was calculated as the product of 4-sulfatase catalytic efficiency and the content of 4-sulfatase in fibroblasts. One patient, 2357, with no clinical signs of MPS VI but with reduced 4-sulfatase activity and protein (both 5% of normal) and dermatansulfaturia, had 5% of normal catalytic capacity. The other 15 MPS VI patient fibroblasts had 0%-1.4% of the catalytic capacity of fibroblasts from normal controls and were representative of the spectrum of MPS VI clinical phenotypes, from severe to mild.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗
PubMed1985

Histochemistry of estrogen sulfatases in human breast diseases.

Two estrogen sulfatases, arylsulfatase C-estrone sulfatase (ASC-ES) and d-equilenin sulfatase (EqS) were demonstrated histochemically in the normal human female breast, in benign breast diseases and in infiltrating mammary ductal carcinomas to study their significance in the pathogenesis of epithelial proliferations. By hydrolyzing estrone sulfate, the amount of which in female blood is about ten times greater than that of estradiol or estrone, estrogen sulfatases can produce a high local concentration of estrogens. A simultaneous azo-coupling method for histochemical demonstration of ASC-ES is described in the present study; EqS was demonstrated by a previously described method. Estrogen sulfatases were not found in the normal female breast. Both estrogen sulfatases were found in epithelial cells in some examples of mastopathic disease and in fibroadenomas, while ASC-ES was found in periductal fibroblasts. In some cases of infiltrating ductal carcinomas, estrogen sulfatases were present in carcinoma cells. In most of these tumors ASC-ES activity was observed in fibroblasts around infiltrative cell cords. There was no correlation between the presence of estrogen sulfatases and of hormone receptors in carcinomas. It is concluded that estrogen sulfatases play no role in the early stages of benign or malignant epithelial proliferations. However, the induction of estrogen sulfatases may promote epithelial proliferation in some cases if estrogen receptors are present in epithelial cells.

Adult↗
PubMed1979

Multiple deficiency of mucopolysaccharide sulfatases in mucosulfatidosis.

Fibroblasts of four patients affected with mucosulfatidosis (multiple sulfatase deficiency, Austin variant of metachromatic leukodystrophy) were assayed for activities of the five sulfatases known to degrade mucopolysaccharides. These were iduronide 2-sulfate sulfatase, sulfamidase, N-acetyl-galactosamine 6-sulfate sulfatase, arylsulfatase B (N-acetylgalactosamine 4-sulfate sulfatase), and N-acetylglucosamine 6-sulfate sulfatase. The activities of these five sulfatases were severely depressed, thus confirming the known deficiency of arylsulfatase B and the absence of the Hunter and Sanfilippo III A corrective factors that have iduronide 2-sulfate sulfatase and sulfamidase activity, respectively. Together with earlier reports of the deficiencies of arylsulfatases A and C, cholesteryl sulfatase, and dehydroepiandrosterone sulfatae, mucosulfatidosis is now characterized by the deficiency of nine different sulfatases.

Acetylglucosamine↗
PubMed1998

Different biochemical properties of nuclear and microsomal estrone-3-sulfatases: evidence for the presence of a nuclear isozyme.

In female rats, total estrone-3-sulfatase activity per liver in the nuclear fraction is comparable to the total activity per liver in the microsomal fraction. The combined estrone-3-sulfatase activity in the other fractions (lysosomal, mitochondrial, and cytosolic fractions) is negligible and only accounts for < 5% of the total nuclear or microsomal sulfatase activity. Nuclear and microsomal estrone-3-sulfatases have different pH optima (pH 8.0 and 7.2, respectively). The apparent Km values for the nuclear and microsomal estrone-3-sulfatases are 2.5 and 10.1 microM, respectively, suggesting that the nuclear sulfatase has a considerably higher affinity for estrone-3-sulfate than the microsomal sulfatase. Moreover, the nuclear estrone-3-sulfatase is more sensitive to inhibition by several steroids than the microsomal sulfatase. The results suggest that estrone-3-sulfatase in the nuclear fraction is a different isozyme than that in the microsomal fraction.

Animals↗
PubMed2000

Strong inhibition of estrone-3-sulfatase activity by pregnenolone 16alpha-carbonitrile but not by several analogs lacking a 16alpha-nitrile group.

In recent years, development of potent inhibitors for estrogen sulfatases has become an actively pursued strategy for chemoprevention and/or chemotherapy of estrogen-dependent human breast cancers. We report here our findings that pregnenolone 16alpha-carbonitrile (PCN) is a potent inhibitor of estrone-3-sulfatase activity of rats and also humans. PCN inhibited in a concentration-dependent manner the desulfation of estrone-3-sulfate catalyzed by liver microsomal and nuclear fractions of female Sprague-Dawley rats. The inhibition of estrone-3-sulfatase activity in these two subcellular fractions showed a biphasic pattern, with a highly sensitive phase seen at 78 nM to 1.25 microm of PCN followed by a markedly less-sensitive phase at > 2.5 microm of PCN. Interestingly, several of PCN's structural analogs without a 16alpha-nitrile group showed little or no inhibitory effect on rat liver microsomal E(1)-3-sulfatase activity. Double-reciprocal analysis showed that the inhibition of rat liver microsomal E(1)-3-sulfatase activity by PCN was essentially competitive in nature. When microsomes from six human term placentas were tested for their E(1)-3-sulfatase activity, PCN showed a similar biphasic inhibition of placental E(1)-3-sulfatase. Likewise, several of its structural analogs showed little or no inhibitory effect on placental E(1)-3-sulfatase activity. Computational analysis of the D-ring structure of PCN and other structurally similar analogs used in the study suggests that the potent sulfatase-inhibiting activity of PCN may be partly due to its unique steric orientation and size of the 16alpha-nitrile group. This knowledge may be useful for the rational design of more potent steroidal inhibitors of E(1)-3-sulfatase by introducing an additional nitrile group to their C16alpha-position.

Animals↗
PubMed1996

Inhibition of placental estrone sulfatase activity and MCF-7 breast cancer cell proliferation by estrone-3-amino derivatives.

Estrogen levels in breast tumors of post-menopausal women are as much as 10 times higher than in plasma, presumably due to in situ formation of estrogen. Several lines of evidence indicate that the major source of estrogen in breast cancer cells may be from conversion of estrone sulfate to estrone by the enzyme estrone sulfatase. Inhibitors of estrone sulfatase may thus be potential agents for the treatment of estrogen-dependent breast cancer. We designed and synthesized a series of estrone-3-amino derivatives as potential estrone sulfatase inhibitors. We tested the inhibitory potential of these compounds using human placental microsomes, which contain a substantial amount of estrone sulfatase activity. Several compounds in the series significantly inhibited estrone sulfatase activity of the human placental microsomes when present at 10 microM. The IC50 for the estrone-3-amino compounds ranged from 8.7 to 14.6 microM. We next tested the ability of the estrone-3-amino derivatives to inhibit growth of the estrogen-dependent MCF-7 breast cancer cell line. MCF-7 cells showed substantial proliferation in the presence of 100 nM estrone sulfate in estrogen-free media, indicating that the cells were capable of converting estrone sulfate into estrone. The proliferative effect of estrone sulfate (1 microM) was significantly blocked by the estrone-3-amino derivatives at 10 microM. The magnitude of MCF-7 cell inhibition resulting from treatment with the estrone-3 amino compounds was similar to or exceeded that of Danazol, but was less than the level resulting from treatment with estrone sulfamate. Using data from all of the compounds tested, inhibition of MCF-7 cell proliferation was positively correlated with inhibition of placental estrone sulfatase activity, suggesting that the reduction in cell growth was attributable to the blockade of sulfatase activity. In support of this, there was no relationship between inhibition of estrone sulfatase activity and inhibition of cell growth when the estrogen-independent cell line MDA-MB-231 was used. Our results indicate the possible utility of estrone-3-amino derivatives for inhibition of estrone sulfatase activity. Further, our data support the concept that estrone sulfatase inhibitors may be useful as therapeutic agents for estrogen-dependent breast cancers.

Adenocarcinoma↗
PubMed1999

Development of (p-O-sulfamoyl)-N-alkanoyl-phenylalkyl amines as non-steroidal estrone sulfatase inhibitors.

Estrogen levels in breast tumors of postmenopausal women are as much as 10 times higher than estrogen levels in plasma, presumably due to in situ formation of estrogen. The major source of estrogen in breast cancer cells may be conversion of estrone sulfate to estrone by the enzyme estrone sulfatase. Thus, inhibitors of estrone sulfatase are potential agents for treatment of estrogen-dependent breast cancer. Several steroidal compounds have been developed that are potent estrone sulfatase inhibitors, most notably estrone-3-O-sulfamate. However, these compounds and their metabolites may have undesired effects, including estrogenicity. To avoid the problems associated with a potentially active steroid nucleus, we designed and synthesized a series of nonsteroidal estrone sulfatase inhibitors, the (p-O-sulfamoyl)-N-alkanoyl phenylalkyl amines. The compounds synthesized vary in the length of their alkanoyl chain and in the number of carbons separating the phenyl ring and the carbonyl carbon. The ability of these compounds to inhibit estrone sulfatase activity was tested using human placental microsomes and intact cultured human breast cancer cells. Estrogenicity was also evaluated, using growth of estrogen-dependent human breast cancer cells. All of the test compounds inhibited estrone sulfatase activity of human placental microsomes to some extent, with the most effective compound having an IC50 value of 72 nM. In general, compounds with longer alkanoyl chains (12-14 carbons) were more effective than those with shorter chains. The test compounds also inhibited estrone sulfatase activity in intact cultures of MDA-MB-231 human breast cancer cells. Again, the longer chain compounds were more effective. In both the placental and breast cancer cell sulfatase assays, the optimal distance between the phenyl ring and the carbonyl carbon was 1-2 carbons. The MCF-7 cell proliferation assay revealed that estrone and estrone-3-O-sulfamate were both estrogenic, but the (p-O-sulfamoyl)-N-alkanoyl phenylalkyl amines were not. Our data indicate the utility of (p-O-sulfamoyl)-N-alkanoyl phenyl alkylamines for inhibition of estrone sulfatase activity. Furthermore, our data support the concept that nonsteroidal estrone sulfatase inhibitors may be useful as therapeutic agents for estrogen-dependent breast cancers.

Amines↗
PubMed1984

Complementation of multiple sulfatase deficiency in somatic cell hybrids.

Multiple sulfatase deficiency (MSD) is an inherited disorder characterized by deficient activity of seven different sulfatases. Genetic complementation for steroid sulfatase (STS), arylsulfatase A, and N-acetylgalactosamine 6-SO4 sulfatase was demonstrated in somatic cell hybrids between MSD fibroblasts and mouse cells ( LA9 ) or Chinese hamster cells ( CHW ). In an electrophoretic system that separates human and rodent STS isozymes, enzyme from hybrids migrated as human enzyme. We concluded that the rodent cell complemented the MSD deficiency and allowed normal expression of the STS structural gene. Some MSD- LA9 hybrids showed significant levels of human arylsulfatase A activity, as shown by the immunoprecipitation of active enzyme by human-specific antiserum. Complementation was also suggested for N-acetylgalactosamine 6- sulfatate sulfatase (GalNAc-6S sulfatase) in several MSD- LA9 hybrids by the demonstration of a significant increase in activity (10-fold) over that of the GalNAc-6S sulfatase-deficient parental mouse and MSD cells. Thus, it was possible to demonstrate complementation for more than one sulfatase in a single MSD-rodent hybrid. Normal levels of sulfatase activity in hybrids indicate that the sulfatase structural genes are intact in MSD cells.

Animals↗