Complete genome sequence of Vibrio fischeri: a symbiotic bacterium with pathogenic congeners

Vibrio fischeri belongs to the Vibrionaceae, a large family of marine gamma-proteobacteria that includes several dozen species known to engage in a diversity of beneficial or pathogenic interactions with animal tissue. Among the small number of pathogenic Vibrio species that cause human diseases are Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus, the only members of the Vibrionaceae that have had their genome sequences reported. Nonpathogenic members of the genus Vibrio, including a number of beneficial symbionts, make up the majority of the Vibrionaceae, but none of these species has been similarly examined. Here we report the genome sequence of V. fischeri ES114, which enters into a mutualistic symbiosis in the light organ of the bobtail squid, Euprymna scolopes. Analysis of this sequence has revealed surprising parallels with V. cholerae and other pathogens.

Assessing investment in manual handling risk controls: a scoring system for use in observational studies

Most UK hospitals now have manual handling policies, but few studies have assessed their impact. To facilitate such research, a system for ranking the investment in manual handling risk controls was devised and applied to 109 acute hospitals in the UK. High scoring hospitals performed well on all aspects of manual handling risk management. Low scoring hospitals had a manual handling policy and recorded accidents and sickness absence, but had limited resource for expert manpower and equipment.

Deep Brain Stimulation for Parkinson’s Disease: Association between Stimulation Parameters and Cognitive Performance

Chronic subthalamic nucleus stimulation produces inconsistent patterns of cognitive change in Parkinson's disease patients. Individually tailored stimulation parameters may contribute to this variable pattern of change. Systematic variation of amplitude, pulse width, and rate of stimulation has been reported to produce unique changes in motor and limbic response. To evaluate the association between stimulation parameters and cognitive/behavioral response, neuropsychological performance and stimulation parameter data of 8 Parkinson's disease patients were submitted to Pearson r correlation analysis. Results indicate that each stimulation parameter was significantly associated with a subset of measures. The current findings raise the possibility that adverse cognitive/behavioral responses may be treated through parameter modification while maintaining motor symptom efficacy.

Glucocorticoid Ligands Specify Different Interactions with NF-κB by Allosteric Effects on the Glucocorticoid Receptor DNA Binding Domain

Glucocorticoids inhibit inflammation by acting through the glucocorticoid receptor (GR) and powerfully repressing NF-kappaB function. Ligand binding to the C-terminal of GR promotes the nuclear translocation of the receptor and binding to NF-kappaB through the GR DNA binding domain. We sought how ligand recognition influences the interaction between NF-kappaB and GR. Both dexamethasone (agonist) and RU486 (antagonist) promote efficient nuclear translocation, and we show occupancy of the same intranuclear compartment as NF-kappaB with both ligands. However, unlike dexamethasone, RU486 had negligible activity to inhibit NF-kappaB transactivation. This failure may stem from altered co-factor recruitment or altered interaction with NF-kappaB. Using both glutathione S-transferase pull-down and bioluminescence resonance energy transfer approaches, we identified a major glucocorticoid ligand effect on interaction between the GR and the p65 component of NF-kappaB, with RU486 inhibiting recruitment compared with dexamethasone. Using the bioluminescence resonance energy transfer assay, we found that RU486 efficiently recruited NCoR to the GR, unlike dexamethasone, which recruited SRC1. Therefore, RU486 promotes differential protein recruitment to both the C-terminal and DNA binding domain of the receptor. Importantly, using chromatin immunoprecipitation, we show that impaired interaction between GR and p65 with RU486 leads to reduced recruitment of the GR to the NF-kappaB-responsive region of the interleukin-8 promoter, again in contrast to dexamethasone that significantly increased GR binding. We demonstrate that ligand-induced conformation of the GR C-terminal has profound effects on the functional surface generated by the DNA binding domain of the GR. This has implications for understanding ligand-dependent interdomain communication.

Analysis of co-factor function in a glucocorticoid-resistant small cell carcinoma cell line

Human small cell lung carcinoma (SCLC) tumours exhibit neuroendocrine differentiation, secreting hormones such as ACTH and related peptides. While glucocorticoids inhibit ACTH secretion from the pituitary, this does not occur in SCLC tumours and SCLC cell lines. Failure of glucocorticoids to suppress ACTH peptides is accompanied by a global lack of glucocorticoid action in a number of SCLC cell lines. In the human SCLC cell line, COR L103, activation of a human tyrosine aminotransferase (TAT3)-luciferase reporter gene is resistant to glucocorticoids despite similar glucocorticoid receptor (GR) expression to the glucocorticoid-sensitive A549 human lung cancer cell line; moreover, the GR is free of deleterious mutations. Over-expression of a wild-type GR restores glucocorticoid regulation of TAT3-luciferase, and this is enhanced when the activation function (AF)-2 domain is deleted but much reduced when the AF-1 domain is deleted. This suggests aberrant AF-2 activation domain function. We identified defective steroid receptor co-activator 1 (SRC1) recruitment to the GR AF-2 in COR L103 cells, although SRC1 was successfully recruited to the steroid X receptor with rifampicin, suggesting a defect in the GR. Analysis of other GR C-terminal co-factors identified increased expression of nuclear co-repressor (NCoR) in COR L103 cells. To determine the impact of this, NCoR was over-expressed in A549 cells, where it reduced GR transactivation by 55%. In summary, glucocorticoid resistance is associated with altered SRC protein recruitment and increased expression of NCoR in these SCLC cells, suggesting that glucocorticoid sensitivity may be modified by subtle changes in co-factor recruitment.

Regulation of glucocorticoid receptor gamma (GRgamma) by glucocorticoid receptor haplotype and glucocorticoid

OBJECTIVE

To measure glucocorticoid receptor gamma (GRgamma) expression in transformed lymphocytes from individuals of known GR gene haplotype. Recently, a glucocorticoid receptor haplotype (GAT) has been described that associates with increased sensitivity to dexamethasone. As there is strong linkage disequilibrium across the gene, this haplotype is likely to extend through exon 3, altered splicing of which generates the GRgamma isoform, a splice variant with impaired transactivation activity. Therefore we proposed that the GR haplotype affects glucocorticoid sensitivity either by influencing GRgamma expression basally, or in response to Gc exposure.

DESIGN

We have measured expression of GRgamma, using a validated RT-PCR assay in human B lymphoblast cells of known haplotype under basal conditions, and after dexamethasone treatment.

PATIENTS

The A549 human lung cell line and normal volunteers, five with the GAT GR haplotype and three with the CGA haplotype.

MEASUREMENTS

Relative expression of GRgamma compared to total GR mRNA.

RESULTS

GRgamma made up 5-6% of all the GR transcripts. There was no effect of carriage of the GR gene GAT haplotype on this expression. There was no effect of dexamethasone on relative expression of GRgamma.

CONCLUSIONS

We propose that the GRgamma isoform is a product of constitutive splicing, that it does not explain the GR haplotype association with altered glucocorticoid sensitivity, and is unlikely to play an important physiological role in affecting glucocorticoid sensitivity. As glucocorticoids do not affect GRgamma expression, relative to total GR, this splice variant is unlikely to influence glucocorticoid treatment response.

Manual handling risk controls in hospitals (MARCH): a cross-sectional survey of UK hospitals

Injury and ill health among healthcare staff associated with handling patients is an important area of risk for UK National Health Service (NHS) employers. Since the introduction of a specific legal duty to control this risk in 1992, many Trusts have developed manual handling risk management strategies. Anecdotally, however, practice varies between Trusts and there is no published description of common practice among NHS employers. The latter would be useful as a benchmark for risk managers. Therefore, we undertook a cross-sectional survey of 158 UK trusts (81% of those invited) using a structured interviewer-administered questionnaire to collect information about manual handling risk controls. Most Trusts had basic systems for risk management, including defined management accountability, written policies, provision of handling equipment, training, expert advice about manual handling and access to occupational health services and physiotherapy for injured employees. However, there was wide variation in important aspects, including the extent of expert manpower and criteria for referral to occupational health. Arrangements for monitoring risk controls were generally poor, and the variation in practice was a cause for concern. These data will help NHS employers by providing a benchmark against which to measure and develop risk management systems for manual handling. Future research should aim to develop standards through consensus opinion and ultimately evidence of effectiveness of risk controls.

The role of the mother-child interaction as a factor in nursing caries (ECC): a preliminary communication

AIM

This was to investigate the role of the mother-child interaction as a factor in nursing caries.

METHODS

A convenience sample of 34 parents whose children had been diagnosed with nursing caries (Early Childhood Caries, ECC) was gathered. A series of non-structured interviews with parents were conducted. The interviews were transcribed and analysed using Grounded Theory.

RESULTS

The overarching category which explained the basic social process associated with nursing caries was 'nursing caries mothering'. The three categories which emerged characterised the basic social process of 'nursing caries mothering' were regressive mothering, culpable mothering and convenience mothering.

CONCLUSION

ECC is characterised by regressive mothering, culpable mothering and convenience mothering. In each of these typologies the bottle once used to nourish the baby has become imbued with other behaviours and meanings. An awareness of these meanings of what the breast/bottle have come to represent should be incorporated and form a central strand of a joined-up health promotion approach.

Melorheostosis of the tenth and eleventh thoracic vertebrae crossing the facet joint: a rare cause of back pain

Melorheostosis affecting the axial skeleton is a rare condition. We present a case affecting a single thoracic zygoapophyseal (facet) joint that proved to be a diagnostic challenge. CT, MRI and radionuclide imaging with surgical and histopathology findings are discussed.

Treatment of osteoarthritis of the hip and knee: a comparison of NSAID use in patients for whom surgery was and was not recommended

OBJECTIVE

To determine if NSAID use was different between OA (hip and/or knee) patients treated surgically to those treated medically.

METHODS

We conducted a case control study, in which cases (n = 433) had had a total joint replacement within a two-year period, while controls (n = 195) had seen a rheumatologist or orthopedic surgeon, and not been recommended for surgery. Current and previous NSAID use was surveyed.

RESULTS

Cases were older than controls (70 vs. 64 years, p < 0.0001), and were more likely to have OA in the hips (45% vs. 21%, p < 0.0001), to have severe OA (p < 0.0001), and to be male (42% vs. 28%, p < 0.0008). Potential confounding variables were statistically adjusted using logistic regression. Although disease duration was similar in cases and controls (9.8 years), cases had tried fewer NSAIDs (1.3 +/- 0.05 vs. 2.3 +/- 0.08 in controls, p < 0.0001). Cases were less likely to have taken any NSAID (86% vs. 94% of controls; OR 0.40, p < 0.007) or to have had intra-articular steroids (OR 0.19, p < 0.0001). Two or more NSAIDs were used (ever) in 38% of cases vs. 70% of controls (p < 0.0001); and 3 or more NSAIDs in 5% vs. 38% (p < 0.0001). Women were less apt to have obtained total joint replacements (OR 0.62, p < 0.0001), including TKRs even when adjusting for severity of OA.

CONCLUSIONS

NSAIDs are used less by orthopedic surgeons than rheumatologists in our centre. Some subjects were offered a joint replacement without even a failure of medical management. The reasons for differences in prescribing trends are unknown. Referral biases may exist.

Disaggregation of collective dose--a worked example based on future discharges from the Sellafield nuclear fuel reprocessing site, UK

Collective dose has long been advocated as an important measure of the detriment associated with practices that involve the use of radioactivity. Application of collective dose in the context of worker protection is relatively straightforward, whereas its application in the context of discharges to the environment can yield radically different conclusions depending upon the population groups and integration times that are considered. The computer program PC-CREAM98 has been used to provide an indicative disaggregation into individual dose bands of the collective dose due to potential future radioactive discharges from the nuclear fuel reprocessing site at Sellafield in the UK. Two alternative discharge scenarios are considered, which represent a 'stop reprocessing early, minimum discharge' scenario and a 'reprocessing beyond current contracts' scenario. For aerial discharges, collective dose at individual effective dose rates exceeding 0.015 microSv y(-1) is only incurred within the UK, and at effective dose rates exceeding 1.5 microSv y(-1) is only incurred within about 20 km of Sellafield. The geographical distribution of collective dose from liquid discharges is harder to assess, but it appears that collective dose incurred outside the UK is at levels of individual effective dose rate below 1.5 microSv y(-1), with the majority being incurred at rates of 0.002 microSv y(-1) or less. In multi-attribute utility analyses, the view taken on the radiological detriment to be attributed to the two discharge scenarios will depend critically on the weight or monetary value ascribed to collective doses incurred within the differing bands of individual dose rate.

Randomisation in trials: do potential trial participants understand it and find it acceptable?

OBJECTIVE

To examine lay persons' ability to identify methods of random allocation and their acceptability of using methods of random allocation in a clinical trial context.

DESIGN

Leaflets containing hypothetical medical, non-medical, and clinical trial scenarios involving random allocation, using material from guidelines for trial information leaflets.

SETTING AND PARTICIPANTS

Adults attending further education colleges (n = 130), covering a wide range of ages, occupations, and levels of education.

MAIN MEASURES

Judgements of whether each of five methods of allocation to two groups was random in a medical or non-medical scenario. Judgements of whether these allocation methods were acceptable in a randomised clinical trial scenario, with or without a scientific justification for randomisation.

RESULTS

The majority of our group of participants judged correctly that allowing people their preference was not random, and that the following were random: using a computer with no information about the individual (recommended wording for MREC trial leaflets), tossing a coin, drawing a name out of a hat. Judgements were split over allocating people in turn (not a random allocation method but shares features with randomisation). Judgements were no different in medical and non-medical scenarios. Few of the correctly identified random methods were judged to be acceptable in a clinical trial scenario. Inclusion of a scientific justification for randomising significantly increased the acceptability of only one random method: allocation by computer.

CONCLUSIONS

Current UK guidelines' recommended description of random allocation by computer seems warranted. However, while potential trial participants may understand what random allocation means, they may find it unacceptable unless offered an acceptable justification for its use.

Glucocorticoid sensitivity is determined by a specific glucocorticoid receptor haplotype

Differences in glucocorticoid (GC) sensitivity may underlie both common diseases (e.g. hypertension) and variability in response to treatment with GCs (e.g. asthma). We tested the potential involvement of the GC receptor (GR) gene in mediating GC sensitivity using haplotype analysis and a low-dose dexamethasone suppression test. Linkage disequilibrium across the GR gene was determined in 216 U.K. Caucasians, and 116 had a 0.25-mg overnight dexamethasone suppression test. Very strong linkage disequilibrium was observed across the GR gene with only four haplotypes accounting for 95% of those observed. Haplotype pattern mining and linear regression analyses independently identified a three-marker haplotype, across intron B, to be significantly associated with low postdexamethasone cortisol (P = 0.03). Carriage of this haplotype occurred in 41% of the individuals with low postdexamethasone cortisol vs. 23% in the combined other quartiles (odds ratio 2.4, 95% confidence interval 0.9-6.3, P = 0.05). This is the first comprehensive, haplotype based analysis of the GR gene. A three-point haplotype, within intron B, is associated with enhanced sensitivity to GCs. This haplotype may help predetermine variation in clinical response to GC therapy and also assist the understanding of diseases related to GC production.

Toxicity, recurrence and survival after adjuvant radiotherapy treatment for FIGO stage I cancer of the endometrium

We conducted a retrospective observational study to determine the rate of toxicity, pattern of tumour recurrence and survival associated with radiotherapy treatment for FIGO stage I cancer of the endometrium. All patients had undergone definitive surgery and had been referred to the oncology department of the University Hospital Birmingham, U.K. Two hundred and forty-five women were included in the study; 228 patients were treated with radiotherapy; 160 had external beam radiation alone; 32 had vaginal vault brachytherapy alone; 36 patients had both modalities; and 17 patients were not given radiotherapy. There were nine cases of Grade 3 and 4 radiation reactions, of which four were acute, four were late and one was acute and late toxicity. The severity of both acute and late radiation effects was significantly associated with the delivery of vault brachytherapy (external beam radiotherapy alone compared with brachytherapy alone (1/158 vs 3/32; P = 0.02). Thirty-four patients were diagnosed with tumour recurrence (11 distant, 14 local, 4 patients had both distant and local disease and 5 patients had recurrence diagnosed at the time of death). Patients who received no radiotherapy were at greater risk of local pelvic tumour recurrence (P < 0.0001; hazard ratio [HR] 9.6, 95% confidence interval (CI) 3.5-26.3). Vaginal vault brachytherapy had no discernible effect on the pattern of tumour recurrence. Forty-six patients died during the follow-up period, 28 of these were attributable to carcinoma of the endometrium. There was no difference in survival between the four treatment groups (P = 0.68). The overall 5-year survival rate in our study group was 89.6% (85.4-93.8%). In a proportional hazards model, tumour grade (HR 2.0 per level [1.25, 3.17]; P = 0.004]) and age (HR 1.74 per 10 years [1.12, 2.69]; P = 0.01) were the only factors found to have an independent influence on survival. This study suggests that, although pelvic radiation may not alter overall survival, it does reduce the risk of local disease recurrence. In this study population, vaginal vault brachytherapy using a vaginal stock/dobbie showed no additional benefits compared with external beam radiotherapy; it was, however, associated with a higher rate of both acute and late radiation effects.

Dissociation of steroid receptor coactivator 1 and nuclear receptor corepressor recruitment to the human glucocorticoid receptor by modification of the ligand-receptor interface: the role of tyrosine 735

Within the human glucocorticoid receptor (GR) steroid binding pocket, tyrosine 735 makes hydrophobic contact with the steroid D ring. Substitution of tyrosine735 selectively impairs glucocorticoid transactivation but not transrepression. We now show, using both mammalian two-hybrid and glutathione-S-transferase pull downs, that such substitutions reduce interaction with steroid receptor coactivator 1, both basally and in response to agonist binding. Using a yeast two-hybrid screen we identified one of the three nuclear receptor interacting domains (NCoR-N1) of nuclear receptor corepressor (NCoR) as interacting with the GR C terminus in an RU486-specific manner. This was confirmed in mammalian two-hybrid experiments, and so we used the NCoR-N1 peptide to probe the GR C-terminal conformation. Substitution of Tyr735phe, Tyr735val, and Tyr735 ser, which impaired steroid receptor coactivator 1 (SRC1) interaction, enhanced NCoR-N1 recruitment, basally and after RU486. RU486 did not direct SRC1 recruitment to any of the GR constructs, and dexamethasone did not allow NCoR-N1 recruitment. Using a glutathione-S-transferase pull-down approach, the NCoR-N1 peptide was found to bind the full-length GR constitutively, and no further induction was seen with RU486, but it was reduced by dexamethasone. As both SRC1 and NCoR are predicted to recognize a common hydrophobic cleft in the GR, it seems that changes favorable to one interaction are detrimental to the other, thus identifying a molecular switch.

Recurrent stent thrombosis associated with lupus anticoagulant due to renal cell carcinoma

A case is presented of recurrent stent thrombosis unexplained by angiographic appearance, which subsequently revealed a diagnosis of antiphospholipid syndrome secondary to renal cell carcinoma.

Haplotype analysis of the polymorphic human vascular endothelial growth factor gene promoter

The human vascular endothelial growth factor (VEGF) gene is unusually polymorphic,and there is evidence for inheritance of conserved haplotypes. One haplotype, carrying polymorphisms at -460/+405, is associated with enhanced production of VEGF in vitro. The VEGF promoter is activated by phorbol esters and, in endometrial cells, by estrogen. We have analyzed the impact of the common -460/+405 polymorphism on both basal and stimulated VEGF transcription using the human breast cancer cell line MCF7. Because the VEGF promoter is so highly polymorphic, haplotypes were established and analyzed. Carriage of the -460/+405 polymorphisms increased basal promoter activity by 71% compared with the wild-type sequence. However, this effect was dependent on colinearity with a series of further 5' sequence polymorphisms. The -460/+405 polymorphism also increased the mean induction by phorbol ester from 5-fold to 8.5-fold. In contrast to earlier studies in endometrial cells, none of the human VEGF promoter constructs was regulated by estrogen. Overexpression of the estrogen receptor did not confer estrogen regulation to VEGF, implying cell type-specific hormonal regulation. Therefore, carriage of the -460/+405 polymorphism significantly alters VEGF promoter activity and responsiveness. This has implications for the inherited susceptibility of common diseases.

Mutation screening of the macrophage migration inhibitory factor gene: positive association of a functional polymorphism of macrophage migration inhibitory factor with juvenile idiopathic arthritis

OBJECTIVE

To determine if polymorphisms of the macrophage migration inhibitory factor (MIF) gene are associated with juvenile idiopathic arthritis (JIA).

METHODS

Denaturing high-performance liquid chromatography was used to screen the MIF gene in 32 UK Caucasian controls and 88 UK Caucasian JIA patients. Ninety-two healthy UK Caucasian controls were then genotyped for each of the polymorphic positions identified. A panel of 526 UK Caucasian JIA patients and 259 UK Caucasian controls were subsequently genotyped for a single-nucleotide polymorphism (SNP) identified in the 5'-flanking region of the gene, using SNaPshot ddNTP primer extension and capillary electrophoresis. The functional significance of this polymorphism was also studied using luciferase-based reporter gene assays in human T lymphoblast and epithelial cell lines.

RESULTS

A tetranucleotide repeat CATT((5-7)) beginning at nucleotide position -794 and 3 SNPs at positions -173 (G to C), +254 (T to C), and +656 (C to G) of the MIF gene were identified. No JIA-specific mutations were found. Allele and genotype frequencies differed significantly between the controls and the JIA patients for the MIF-173 polymorphism. Individuals possessing a MIF-173*C allele had an increased risk of JIA (34.8% versus 21.6%) (odds ratio 1.9, 95% confidence interval 1.4-2.7; P = 0.0002). Furthermore, the MIF-173* G and C variants resulted in altered expression of MIF in a cell type-specific manner. Serum levels of MIF were also significantly higher in individuals who carried a MIF-173*C allele (P = 0.04).

CONCLUSION

The -173-MIF*C allele confers increased risk of susceptibility to JIA. Our data suggest a cell type-specific regulation of MIF, which may be central to understanding its role in inflammation.

Lacrimal duct stenosis and other ocular toxicity associated with adjuvant cyclophosphamide, methotrexate and 5-fluorouracil combination chemotherapy for early stage breast cancer

Certain side-effects of chemotherapy are well recognized but ocular toxicity is often underestimated. This retrospective study was undertaken after we became aware of a case of irreversible lacrimal duct stenosis in a woman receiving adjuvant chemotherapy for early stage breast cancer. Using the chemotherapy records, 128 patients who received adjuvant cyclophosphamide, methotrexate and 5-fluorouracil combination chemotherapy for early stage breast cancer over a 2 1/2-year period were identified. The case notes of these patients were reviewed and an 18% incidence of ocular side-effects, including four other cases of epiphora, was identified. The epiphora resolved fully on completion of chemotherapy in these four patients but not in the index patient. The optimal management of these side-effects is unclear but it needs to be tailored to the particular toxicity experienced by the patient.

Polymorphisms of the human prolactin gene--implications for production of lymphocyte prolactin and systemic lupus erythematosus

Hyperprolactinaemia is associated with systemic lupus erythematosus (SLE) but the mechanism is unknown. Prolactin is expressed not only by pituitary lactotrophic cells but also by T-lymphocytes under the control of an alternative upstream promoter region. T-lymphocytes from SLE patients have been shown to secrete more prolactin than controls, thus implying a possible underlying difference in regulation. This may be due to genetic polymorphism that can be determined by scanning for mutations and using a variety of methods to determine their function. A polymorphism may also be used in disease association studies as it may be in linkage disequilibrium with a disease gene on the same haplotype. Single nucleotide polymorphisms (SNPs) have been found across the prolactin gene region including the extrapituitary and the pituitary promoter regions. These SNPs have been examined for genetic association with SLE and potential effects upon the function of the gene. One SNP in the lymphocyte specific upstream promoter affects prolactin transcription and disease association studies in a cohort of SLE cases demonstrated an increased frequency of the PRL-1149 G allele compared to control subjects. This indicates a possible mechanism for the association of prolactin with SLE. Although prolactin is likely to be one of several predisposing factors in the pathogenesis and progression of SLE, this suggests that manipulation of lymphocyte prolactin production (rather than pituitary production) might be a useful therapeutic approach.

Genetic engineering of the glucocorticoid receptor by fusion with the herpes viral protein VP22 causes selective loss of transactivation

The development of methods for engineering proteins with novel properties opens the way to manipulating intracellular processes in a therapeutically useful way. Glucocorticoids, acting via glucocorticoid receptors (GR), are potent anti-inflammatory agents, acting to oppose nuclear factor kappa B (NF kappa B) function. The herpes viral protein, VP22, has been reported to confer intercellular trafficking activity on 'cargo' proteins, potentially facilitating gene therapy with intracellular proteins. VP22GR, resulting from the addition of VP22 to the N terminal of GR, was equipotent with the wild-type GR in opposing NF kappa B p65-driven expression of an NF kappa B reporter gene. Surprisingly, VP22GR was incapable of inducing transactivation of positive glucocorticoid reporter genes (MMTV-luc and TAT3-luc). Furthermore, the VP22GR had powerful dominant negative activity on both endogenous and exogenous GR transactivation. VP22GR was cytoplasmic in quiescent cells, and after hormone addition underwent nuclear translocation to share the same distribution as the GR. The ability of the VP22GR to selectively confer and enhance glucocorticoid-dependent transrepression of NF kappa B may be of use therapeutically in e.g. transplant rejection, inflammatory arthritis or asthma.

Failure of steroid regulation of the MMTV promoter in a small cell lung cancer cell line is caused by a DNA sequence flanking the glucocorticoid response element

We have previously described a panel of human small cell lung carcinoma (SCLC) cell lines that have profound glucocorticoid resistance, resulting from various molecular defects in glucocorticoid signalling. However, in one SCLC cell line, CORL103, the cause of the resistance is unknown. These cells are refractory to dexamethasone stimulation of MMTV even when exogenous wild-type glucocorticoid receptor (GR) is co-transfected. This is in contrast to cell lines DMS79 and CORL24 where resistance is overcome by transfection of the wild-type receptor. Sequencing of the GR from CORL103 cells revealed two point mutations, but neither of these induced dominant negative activity. Steroid hormone resistance extended to mineralocorticoid and progesterone receptor (MR, PR) activation of MMTV-luc, whereas oestrogen and thyroid hormone receptor transactivation were normal. A simpler reporter, TAT3-luc, containing three copies of the tyrosine aminotransferase glucocorticoid response element (GRE), was responsive when transfected into CORL103 cells with GR, MR and PR expression vectors and activated with their respective ligands. Similarly, pHH-luc and pAH-luc (truncated MMTV variants containing the GRE region, both derived from a different strain of MMTV), were effectively transactivated with dexamethasone. This suggests that the minor changes in the flanking sequence of the MMTV promoter are critically important in determining steroid responsiveness in CORL103 cells. We propose that minor differences in MMTV may determine recruitment of co-factors, which destabilise GR binding to the MMTV GREs. These findings represent a new, selective, model of glucocorticoid resistance that may explain specific cell and target gene differences in glucocorticoid sensitivity.