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M J Reed

Publications and source records attributed to M J Reed.

At least 19 recordsLinked to original sources

The role of aromatase and 17-beta-hydroxysteroid dehydrogenase type 1 mRNA expression in predicting the clinical outcome of human breast cancer.

INTRODUCTION: There is substantial evidence that breast cancer tissue contains all the enzymes responsible for the local biosynthesis of estrogens from circulating precursors. The cytochrome P-450 aromatase enzyme complex is responsible for the conversion of C19 androgens to estrogens and 17-beta-hydroxysteroid dehydrogenase (17-I(2)-HSD) type 1 catalyses the inter-conversion of estrone to the biologically more potent estradiol. The gene encoding for the cytochrome P-450 aromatase is known as CYP19 (15q21.2). It is well established that increased exposure to local estrogens is an important risk factor in the genesis and growth of breast cancer. The aim of this study is to investigate the relationship between CYP19 and 17-beta-HSD type 1A mRNA expression and clinico-pathological parameters of human breast cancer. METHODS: One hundred and twenty seven tumor tissues and 33 normal tissues were analyzed. The levels of transcription of CYP19 and 17-beta-HSD type 1 were determined using real-time quantitative PCR. The mRNA expression was normalized against CK19. Levels of expression were analyzed against tumorâ's stage, grade, nodal status, local relapse, distant metastasis and survival over a 120A months follow up period. In addition, the levels were analyzed against estrogen receptor (ER) and HER1-4 status. RESULTS: Overall, high tumor levels of mRNA expression of CYP19 and 17-beta-HSD type 1 correlated with poor survival (p=0.0105 and p=0.0182, respectively). Increased levels of CYP19 mRNA expression positively correlated with disease progression as levels were significantly higher in samples of patients who had distant metastasis and local recurrence and/or died of breast related causes when compared to those who were disease free for >10 years (p=0.0015). We also observed higher levels of CYP19 mRNA in tumor samples compared to normal breast tissue. However, this reached statistical significance only when comparing grade 1 tumors with normal tissue (p=0.01). There was no correlation between CYP19á mRNA expression and tumor stage, lymph node status and tumor grade. There was however a trend for a positive correlation between CYP19 and ER mRNA expressions (p=0.06). No significant difference in 17-beta-HSD type 1 expression between normal and cancerous tissues was observed. In tumor samples, we observed an increase in levels correlating with tumor's grade. This correlation was statistically significant when we compared grade 1 with grade 2 and grade 1 with grade 3 (p=0.0031 and 0.0251, respectively). CONCLUSION: Our study shows that higher levels of the enzymes responsible for the local biosynthesis of estrogens especially aromatase are associated with a poor clinical outcome in patients with breast cancer.

17-Hydroxysteroid Dehydrogenases↗

The regulation and inhibition of 17beta-hydroxysteroid dehydrogenase in breast cancer.

17Beta-hydroxysteroid dehydrogenase Type 1 (17beta-HSD1) has a pivotal role in regulating the synthesis of oestradiol (E2) within breast tumours. In whole body studies in postmenopausal women with breast cancer the conversion of oestrone (E1) to E2 (4.4+/-1.1%) was much lower than the inactivation of E2 to E1 (17.3+/-5.0%). In contrast, an examination of in vivo oestrogen metabolism within breast tumours revealed that whereas little metabolism of E2 occurred, E1 was converted to E2 to a much greater extent in malignant (48+/-14%) than in normal (19+/-6%) breast tissue. Findings from these studies originally suggested that oestrogen metabolism within breast tumours may differ from the mainly oxidative direction found in most other body tissues and that the activity of 17beta-HSD1 might be regulated by tumour-derived factors. Several growth factors (e.g. IGF-I, IGF-II) and cytokines (e.g. IL-6, TNFalpha) have now been identified which can markedly stimulate the activity of 17beta-HSD1 and such a mechanism may account for the high concentrations of E2 found in most breast tumours. Cells of the immune system, which can infiltrate breast tumours, are thought to be a major source of the growth factors and cytokines which can modulate 17beta-HSD1 activity. Given the central role that 17beta-HSD1 has in regulating breast tumour E2 concentrations the development of potent inhibitors of this enzyme has recently attracted considerable attention. Our initial studies in this area explored the use of derivatives of E1 as inhibitors, with 2-ethyl- and 2-methoxy E1 being found to inhibit 17beta-HSD1 activity in T-47D breast cancer cells by 96+/-2 and 91+/-1% respectively at 10 microM, but with a lack of specificity. Using the E1 scaffold a number of potent, selective 17beta-HSD1 inhibitors have now been identified including E1- and 2-ethyl-E1 containing a side chain with a m-pyridylmethylamidomethyl functionality extending from the 16beta position of the steroid nucleus. At 10 microM these compounds both inhibited 17beta-HSD1 activity by >90%, however some inhibition of 17beta-HSD2 activity was exhibited by the E1 derivative (25%) but not the 2-ethyl analogue. It is now apparent that 17beta-HSD1 activity contributes to the high E2 concentrations found in most breast tumours. The identification of potent, selective novel 17beta-HSD1 inhibitors will allow their efficacy to be tested in in vitro and in vivo studies.

Breast Neoplasms↗

Collapse query cause: the management of adult syncope in the emergency department.

Syncope is a commonly encountered problem in the emergency department (ED). Its causes are many and varied, some of which are potentially life threatening. A review was carried out of relevant papers in the available literature, and this article attempts to assimilate current evidence relating to ED management. While the cause of syncope can be identified in many patients, and life threatening conditions subsequently treated, a risk stratification approach should be taken for those in whom a cause is not identified in the ED. Aspects of the history and examination that may help identify high risk patients are explored and the role of investigations to aid this stratification is discussed. Identifying a cardiac cause for syncope is a poor prognostic indicator. Patients with unexplained syncope who have significant cardiac disease should therefore be investigated thoroughly to determine the nature of the underlying heart disease and the cause of syncope, although presently there is little evidence that this improves their dismal prognosis. This risk stratification approach has led to the development of several clinical decision rules, which are discussed along with current international guidelines on syncope management. This review suggests that presently the American College of Emergency Physicians guidelines are the most useful aids specific to the management of syncope in the ED; however, the Osservatorio Epidemiologico sulla Sincope nel Lazio (OESIL) score may also be a useful ED risk stratification tool.

Adult↗

Can we abolish skull x rays for head injury?

OBJECTIVES: To assess the effect of a change in skull x ray policy on the rate of admission, use of computed tomography (CT), radiation dose per head injury, and detection of intracranial injuries; and to compare the characteristics of patients with normal and abnormal head CT. DESIGN: Retrospective cohort study. SETTING: UK paediatric teaching hospital emergency department. PATIENTS: 1535 patients aged between 1 and 14 years with a head injury presenting to the emergency department between 1 August 1998 and 31 July 1999 (control period), and 1867 presenting between 1 August 2002 and 31 July 2003 (first year of new skull x ray policy). INTERVENTION: Hospital notes and computer systems were analysed and data were collected on all patients presenting with a head injury. RESULTS: The abolition of skull x rays in children aged over 1 year prevented about 400 normal skull x rays being undertaken in period 2. The percentage of children undergoing CT rose from 1.0% to 2.1% with no change in the positive CT pick up rate (25.6% v 25.0%). There was no significant change in admission rate (10.9% v 10.1%), and a slight decrease in the radiation dose per head injury (0.042 mSv compared to 0.045 mSv). CONCLUSIONS: Skull x rays can be abandoned in children aged 1 to 14 without a significant increase in admission rate, radiation dose per head injury, or missed intracranial injury. The mechanism and history of the injury and a reduced Glasgow coma scale are probably the most important indicators of significant head injury in children.

Accidents↗

The nature of inhibition of steroid sulphatase activity by tibolone and its metabolites.

Tibolone is used for hormone replacement therapy and acts in a tissue-specific manner being oestrogenic on CNS and bone but not on breast tissues or endometrium. The ability of tibolone and its metabolites to inhibit steroid sulphatase (STS) activity has a crucial role in regulating its tissue-specific effects. In this study, we have examined the ability of tibolone and its non-sulphated and sulphated metabolites to inhibit STS activity in different enzyme preparations and in intact cells. For this, we have used an 'extracellular' method, which measures the amount of product released into culture medium, and an 'intracellular' method, which assesses the extent of product formation within cells. In addition, the nature by which tibolone and some of its metabolites inhibit STS activity was investigated using intact cells and an enzyme kinetic method. In MCF-7 and T47D breast cancer cells and JEG-3 choriocarcinoma cells, which have high STS activity, tibolone and its metabolites were relatively potent inhibitors of STS activity (33-57% inhibition at 10 microM) using the extracellular assay method. In HOS-TE-85 osteoblast-like cells, tibolone and its Delta-4 metabolite were relatively inactive whereas the 3alpha/3beta-hydroxy metabolites and their sulphated conjugates inhibited activity by 39-55%. When STS activity was assessed in HOS-TE-85 cells using an 'intracellular' method tibolone and its 3beta-hydroxy metabolite were inactive. Pre-treatment of breast cancer cells and JEG-3 cells, and removal of drugs prior to assaying for STS activity, revealed that in these cells tibolone and its metabolites were acting mainly as reversible inhibitors. This finding was confirmed in an enzyme kinetic study to measure concentration-dependent STS inhibition. In HOS-TE-85 cells, pre-treatment of cells and removal of compounds before assaying for remaining STS activity indicated that some tibolone metabolites appeared to stimulate STS activity. Possible mechanisms by which this might occur are discussed but, if confirmed, this could contribute to the positive oestrogenic effects that tibolone has on bone.

Enzyme Inhibitors↗

The effects of 2-methoxyoestrogen sulphamates on the in vitro and in vivo proliferation of breast cancer cells.

2-Methoxyoestrogen sulphamates are a new class of compounds, which inhibit breast cancer cell proliferation and are also potent inhibitors of steroid sulphatase (STS) activity. In the present study, we have used two cell proliferation assays (MTS and AB) to identify potent new compounds in this class. Similar IC(50) values were obtained using these assays with two of the most potent compounds identified being 2-methoxyoestradiol-bis-sulphamate (2-MeOE2bisMATE) and 2-methoxyoestradiol-17beta-cyanomethyl-3-O-sulphamate (2-MeOE2CyMATE). Both compounds inhibited the proliferation of MCF-7 (ER+) and MDA-MB-231 (ER-) breast cancer cells. Using the AB assay, which allows repeat measurements of cell proliferation without killing cells, both compounds were shown to inhibit cell proliferation in an irreversible manner. As STS may be involved in the removal of the sulphamoyl moiety of these compounds, which could reduce their potency, their ability to inhibit the proliferation of MCF-7 cells transfected with the cDNA for STS was also examined. Although the STS activity was 20-fold higher in these cells than in non-transfected MCF-7 cells, no decrease in the ability of these compounds to inhibit cell proliferation was detected. To test the efficacy of these compounds in vivo, nude mice were inoculated with MCF-7 cells in Matrigel and stimulated to grow with oestradiol. Three weeks after the oral administration of 2-MeOE2bisMATE or 2-MeOE2CyMATE (20mg/kg/day, 5 days/week) tumour volumes had regressed by 52% and 22%, respectively. Both compounds also inhibited liver and tumour STS activity by >90%. The potent anti-proliferative effects of these compounds, and their ability to inhibit tumour growth and STS activity in vivo, indicates that they are suitable for development as novel therapeutic agents, which should be active against a wide range of cancers.

Breast Neoplasms↗

Regulation of aromatase activity by cytokines, PGE2 and 2-methoxyoestrone-3-O-sulphamate in fibroblasts derived from normal and malignant breast tissues.

Synthesis of oestrone from androstenedione within tumours, by the aromatase enzyme complex, is an important source of oestrogen that is available to support the growth of hormone-dependent breast tumours. In view of the central role that the aromatase enzyme has in oestrogen synthesis there has been considerable interest in understanding its regulation and developing inhibitors to block its action. In the present study we have derived fibroblasts from breast tumours (TFs), tissue proximal to tumours (PFs) and reduction mammoplasty tissue (RMFs) and used them to investigate the regulation of aromatase activity by PGE(2), IL-6 plus its soluble receptor (SR) or TNFalpha. In addition we have examined the ability of 2-methoxyoestrone sulphamate (2-MeOEMATE), a compound which alters microtubule stability, to block the stimulation of aromatase activity by these factors. Basal aromatase activity in PFs was significantly higher (p<0.001) than in TFs or RMFs. The combination of IL-6 plus SR or TNFalpha produced the greatest stimulation of aromatase activity in TFs (up to 61-fold) while having a much lower stimulatory effects on aromatase activity in PFs (up to 60% increase) or RMFs (up to 192% increase). 2-MeOEMATE reduced basal aromatase activity in TFs by 87% and completely abrogated the ability of PGE(2), IL-6 plus SR or TNFalpha to stimulate aromatase activity in these fibroblasts. Results from these studies indicate that while PFs have the highest level of non-stimulated aromatase activity, aromatase activity in TFs shows the greatest response to cytokines. These findings suggest that intrinsic difference may exist for the different types of fibroblasts in the way in which they respond to regulatory factors. The ability of 2-MeOEMATE to block cytokine stimulated aromatase activity suggests that, in addition to its other anti-cancer properties, this compound may also act to inhibit cytokine-stimulated aromatase activity in breast tumours.

Aromatase↗

Can an airway assessment score predict difficulty at intubation in the emergency department?

AIM: To assess whether an airway assessment score based on the LEMON method is able to predict difficulty at intubation in the emergency department. METHODS: Patients requiring endotracheal intubation in the resuscitation room of a UK teaching hospital between June 2002 and September 2003 were assessed on criteria based on the LEMON method. At laryngoscopy, the Cormack and Lehane grade was recorded. An airway assessment score was devised and assessed. RESULTS: 156 patients were intubated during the study period. There were 114 Cormack and Lehane grade 1 intubations, 29 grade 2 intubations, 11 grade 3 intubations, and 2 grade 4 intubations. Patients with large incisors (p<0.001), a reduced inter-incisor distance (p<0.05), or a reduced thyroid to floor of mouth distance (p<0.05) were all more likely to have a poor laryngoscopic view (grade 2, 3, or 4). Patients with a high airway assessment score were more likely to have a poor laryngoscopic view compared with those patients with a low airway assessment score (p<0.05). CONCLUSIONS: An airway assessment score based on criteria of the LEMON method is able to successfully stratify the risk of intubation difficulty in the emergency department. Patients with a poor laryngoscopic view (grades 2, 3, or 4) were more likely to have large incisors, a reduced inter-incisor distance, and a reduced thyroid to floor of mouth distance. They were also more likely to have a higher airway assessment score than those patients with a good laryngoscopic view.

Adult↗

Imaging infants with head injury: effect of a change in policy.

OBJECTIVE: Head injury is one of the commoner injuries presenting to the emergency department (ED). Infants are hard to assess clinically and emphasis has been placed on radiological examination. Skull radiographs, however, are not a reliable indicator of intracranial injury. As a result of this the policy in this ED was revised so that skull radiographs were only to be performed in those infants less than 1 year with visible evidence of head injury or a suspicious history for non-accidental injury. METHODS: Retrospective cohort study of all infants less than 1 year who presented with head trauma to the ED of a paediatric teaching hospital between 1 August 1998 and 31 July 1999, and between 1 August 2002 and 31 July 2003. Hospital notes and radiology computer systems were examined and data were collected and analysed. RESULTS: 181 infants aged less than 1 year presenting to the ED in 1998/9 and 190 infants in 2002/3. Altogether 140 (77.3%) infants had a skull radiograph in 1998/9, five (3.6%) identified skull fractures. During 2002/3, 56 (29.5%) infants had a radiograph, a reduction of 47.5%, of which three (5.4%) had skull fractures. All fractures had reported haematomas to their scalp. The change in policy decreased the total radiation dose to the population by 9.4 mSv. No significant injuries were missed as a result of the change in policy. INTERPRETATION: In infants under 1 year, unless non-accidental injury is suspected, it is suggested that skull radiographs should only be performed when there are visible signs of a head injury.

Clinical Protocols↗

Steroid sulfatase: molecular biology, regulation, and inhibition.

Steroid sulfatase (STS) is responsible for the hydrolysis of aryl and alkyl steroid sulfates and therefore has a pivotal role in regulating the formation of biologically active steroids. The enzyme is widely distributed throughout the body, and its action is implicated in physiological processes and pathological conditions. The crystal structure of the enzyme has been resolved, but relatively little is known about what regulates its expression or activity. Research into the control and inhibition of this enzyme has been stimulated by its important role in supporting the growth of hormone-dependent tumors of the breast and prostate. STS is responsible for the hydrolysis of estrone sulfate and dehydroepiandrosterone sulfate to estrone and dehydroepiandrosterone, respectively, both of which can be converted to steroids with estrogenic properties (i.e., estradiol and androstenediol) that can stimulate tumor growth. STS expression is increased in breast tumors and has prognostic significance. The role of STS in supporting tumor growth prompted the development of potent STS inhibitors. Several steroidal and nonsteroidal STS inhibitors are now available, with the irreversible type of inhibitor having a phenol sulfamate ester as its active pharmacophore. One such inhibitor, 667 COUMATE, has now entered a phase I trial in postmenopausal women with breast cancer. The skin is also an important site of STS activity, and deficiency of this enzyme is associated with X-linked ichthyosis. STS may also be involved in regulating part of the immune response and some aspects of cognitive function. The development of potent STS inhibitors will allow investigation of the role of this enzyme in physiological and pathological processes.

Animals↗

Pharmacokinetics of the nonsteroidal steroid sulphatase inhibitor 667 COUMATE and its sequestration into red blood cells in rats.

Breast cancer is a major cause of mortality in Western countries and there is an urgent requirement for novel treatment strategies. The nonsteroidal sulphatase inhibitor 667 COUMATE inhibits hepatic steroid sulphatase and growth of oestrone sulphate stimulated tumours in the nitrosomethylurea-induced rat mammary model. Other compounds that contain an aryl sulphamate moiety, for example, oestrone-3-O-sulphamate, are sequestered into red blood cells (RBCs). The aims of this study were to determine the pharmacokinetics of 667 COUMATE and to investigate its sequestration into RBCs. We administered a single p.o. or i.v. dose (10 mg kg(-1)) of 667 COUMATE to rats and used a high-performance liquid chromatography method to measure the levels of the agent and its putative metabolites in plasma. 667 COUMATE had a bioavailability of 95% and could be detected in plasma for up to 8 h. Using two independent analytical methods, we demonstrated that 667 COUMATE is sequestered by RBCs both ex vivo and in vivo. Previous investigations have revealed that 667 COUMATE is rapidly degraded in plasma ex vivo. In this study, we demonstrate that 667 COUMATE is stabilised due to its sequestration into RBCs. In conclusion, the pharmacological efficacy and high oral bioavailability of 667 COUMATE may be partly a consequence of the ability of RBCs to both protect the agent from metabolic degradation and facilitate its transport to tissues. These data support the further clinical evaluation of this novel endocrine therapeutic agent.

Administration, Oral↗

Role of enzymes and tissue-specific actions of steroids.

Enzymes, such as steroid sulphatase, sulphotransferases and 17 beta-hydroxydehydrogenases, are important in regulating the tissue-specific actions of steroids. These enzymes can exist in different isoforms in different tissues and can be regulated by tissue-specific promoters and factors such as cytokines, prostaglandins and growth factors. The activity of these enzymes and the mechanisms by which they are regulated may help to account for some of the tissue-specific effects of the hormone replacement therapy drug tibolone, which has oestrogenic effects on the bone but not on the breast or endometrium.

Bone and Bones↗

Pharmacokinetics and efficacy of 2-methoxyoestradiol and 2-methoxyoestradiol-bis-sulphamate in vivo in rodents.

2-Methoxyoestradiol (2-MeOE2) is an endogenous oestrogen metabolite that inhibits the proliferation of cancer cells in vitro, and it is also antiangiogenic. In vivo 2-MeOE2, when administered at relatively high doses, inhibits the growth of tumours derived from breast cancer cells, sarcomas and melanomas. Sulphamoylated derivatives of 2-MeOE2 are more potent inhibitors of in vitro breast cancer cell growth than 2-MeOE2. In the present study, we have compared the pharmacokinetic profiles and metabolism of 2-MeOE2 and its sulphamoylated derivative, 2-methoxyoestradiol-bis-sulphamate (2-MeOE2bisMATE), in adult female rats. Their ability to inhibit tumour growth was compared in nude mice bearing xenografts derived from MDA-MB-435 (oestrogen receptor negative) melanoma cancer cells. After a single oral 10 mg kg(-1) dose of 2-MeOE2bisMATE, significant concentrations of this compound were still detectable at 24 h. In contrast, no 2-MeOE2 or metabolites were detected in plasma at any time after a 10 mg kg(-1) oral dose. Thus, the bioavailability of 2-MeOE2 is very low, whereas for 2-MeOE2bisMATE it was 85%. No significant metabolites of 2-MeOE2bisMATE were detected in plasma after oral or intravenous dosing, showing that this drug is resistant to metabolism. In the tumour efficacy model, oral administration of 2-MeOE2bisMATE, at 20 mg kg(-1) day(-1) daily for 28 days, almost completely inhibited tumour growth. Inhibition of tumour growth was maintained for a further 28 days after the cessation of dosing. At this dose level, 2-MeOE2 did not inhibit tumour growth. The resistance to metabolism shown by 2-MeOE2bisMATE and its ability to inhibit tumour growth in vivo suggest that this compound should have considerable potential for development as a novel anticancer drug.

2-Methoxyestradiol↗

2-MeOE2bisMATE induces caspase-dependent apoptosis in CAL51 breast cancer cells and overcomes resistance to TRAIL via cooperative activation of caspases.

2-Methoxyoestradiol (2-MeOE2) is an endogenous oestrogen metabolite which inhibits tubulin polymerisation and has anti-tumour and anti-angiogenic activity. 2-MeOE2 induces apoptosis in a wide range of cancer cell types and has recently been demonstrated to cooperate with TRAIL to induce apoptosis in breast cancer cells. 2-Methoxyoestradiol-3,17-bis-O,O-sulphamate (2-MeOE2bisMATE) is a sulfamoylated derivative of 2-MeOE2 with enhanced activity and improved pharmacokinetic properties, and 2-MeOE2bisMATE is a promising candidate for early clinical trials. It is important, therefore, to understand the mechanisms by which 2-MeOE2bisMATE acts, and whether it retains the ability to cooperate with TRAIL. We demonstrate that 2-MeOE2bisMATE-induced apoptosis of CAL51 breast cancer cells was associated with rapid activation of caspase 3 and 9, but not caspase 8 (as measured by BID cleavage) and was completely prevented by the caspase inhibitor zVADfmk. Interfering with Fas- or TRAIL-receptor function did not prevent 2-MeOE2bisMATE-induced apoptosis. Whereas CAL51 cells were resistant to TRAIL-induced apoptosis, 2-MeOE2bisMATE and TRAIL cooperated to induce cell death. This apoptosis was associated with enhanced activation of caspases, but not increased expression of the DR5 TRAIL receptor, previously demonstrated to be induced by 2-MeOE2. Therefore, 2-MeOE2bisMATE-induced apoptosis is dependent on caspases and like 2-MeOE2, 2-MeOE2bisMATE can overcome resistance to TRAIL by stimulating activation of downstream caspases. Our results suggest that 2-MeOE2bisMATE and TRAIL might be a particularly effective combination of anti-cancer agents.

2-Methoxyestradiol↗

Inhibition of carbonic anhydrase II by steroidal and non-steroidal sulphamates.

Carbonic anhydrases (CAs) are expressed by many solid tumours where they may act to confer a growth advantage on malignant tissues. In this study we have examined the ability of a series of steroidal and non-steroidal sulphamates (originally developed as steroid sulphatase inhibitors) and related compounds to inhibit human CAII (hCAII) activity in vitro. Using a 96-well plate assay, oestrone-3-O-sulphamate (EMATE) and two coumarin-based sulphamate drugs (667 COUMATE and STX 118) were found to have IC(50) values of 25-59 nM for the inhibition of hCAII activity. These compounds therefore have a similar CAII inhibitory potency to that of acetazolamide (IC(50)=25 nM), a known hCAII inhibitor. Docking studies have been performed with selected compounds to the crystal structure of hCAII and excellent correlation of scores with biological activity was observed. This agrees with our recent observations when we were the first to report the inhibition of hCAII by STS inhibitors. These studies and initial results with docking to the crystal structure of the extracellular domain of hCAXII indicate that the STS sulphamate ester inhibitors should also be interesting candidates to pursue as inhibitors of CA isozymes that are over-expressed in human tumours.

Antineoplastic Agents↗