Multi-omics identify falling LRRC15 as a COVID-19 severity marker and persistent pro-thrombotic signals in convalescence

Patients with end-stage kidney disease (ESKD) are at high risk of severe COVID-19. Here, we perform longitudinal blood sampling of ESKD haemodialysis patients with COVID-19, collecting samples pre-infection, serially during infection, and after clinical recovery. Using plasma proteomics, and RNA-sequencing and flow cytometry of immune cells, we identify transcriptomic and proteomic signatures of COVID-19 severity, and find distinct temporal molecular profiles in patients with severe disease. Supervised learning reveals that the plasma proteome is a superior indicator of clinical severity than the PBMC transcriptome. We show that a decreasing trajectory of plasma LRRC15, a proposed co-receptor for SARS-CoV-2, is associated with a more severe clinical course. We observe that two months after the acute infection, patients still display dysregulated gene expression related to vascular, platelet and coagulation pathways, including PF4 (platelet factor 4), which may explain the prolonged thrombotic risk following COVID-19.

Immune responses following 3rd and 4th doses of heterologous and homologous COVID-19 vaccines in kidney transplant recipients

BACKGROUND

Solid organ transplant recipients have attenuated immune responses to SARS-CoV-2 vaccines. In this study, we report on immune responses to 3rd- (V3) and 4th- (V4) doses of heterologous and homologous vaccines in a kidney transplant population.

METHODS

We undertook a single centre cohort study of 724 kidney transplant recipients prospectively screened for serological responses following 3 primary doses of a SARS-CoV2 vaccine. 322 patients were sampled post-V4 for anti-spike (anti-S), with 69 undergoing assessment of SARS-CoV-2 T-cell responses. All vaccine doses were received post-transplant, only mRNA vaccines were used for V3 and V4 dosing. All participants had serological testing performed post-V2 and at least once prior to their first dose of vaccine.

FINDINGS

586/724 (80.9%) patients were infection-naïve post-V3; 141/2586 (24.1%) remained seronegative at 31 (21-51) days post-V3. Timing of vaccination in relation to transplantation, OR: 0.28 (0.15-0.54), p=0.0001; immunosuppression burden, OR: 0.22 (0.13-0.37), p<0.0001, and a diagnosis of diabetes, OR: 0.49 (0.32-0.75), p=0.001, remained independent risk factors for non-seroconversion. Seropositive patients post-V3 had greater anti-S if primed with BNT162b2 compared with ChAdOx1, p=0.001.Post-V4, 45/239 (18.8%) infection-naïve patients remained seronegative. De novo seroconversion post-V4 occurred in 15/60 (25.0%) patients. There was no difference in anti-S post-V4 by vaccine combination, p=0.50. T-cell responses were poor, with only 11/54 (20.4%) infection-naive patients having detectable T-cell responses post-V4, with no difference seen by vaccine type.

INTERPRETATION

A significant proportion of transplant recipients remain seronegative following 3- and 4- doses of SARS-CoV-2 vaccines, with poor T-cell responses, and are likely to have inadequate protection against infection. As such alternative strategies are required to provide protection to this vulnerable group.

FUNDING

MW/PK received study support from Oxford Immunotec.

Comparison of immunogenicity and clinical effectiveness between BNT162b2 and ChAdOx1 SARS-CoV-2 vaccines in people with end-stage kidney disease receiving haemodialysis: A prospective, observational cohort study

Background

People with end-stage kidney disease, including people on haemodialysis, are susceptible to greater COVID-19 related morbidity and mortality. This study compares the immunogenicity and clinical effectiveness of BNT162B2 versus ChAdOx1 in haemodialysis patients.

Methods

In this observational cohort study, 1021 patients were followed-up from time of vaccination until December 2021. All patients underwent weekly RT-PCR screening. Patients were assessed for nucleocapsid(anti-NP) and spike(anti-S) antibodies at timepoints after second(V2) and third(V3) vaccinations. 191 patients were investigated for T-cell responses. Vaccine effectiveness (VE) for prevention of infection, hospitalisation and mortality was evaluated using the formula VE=(1-adjustedHR)x100.

Findings

45.7% (467/1021) had evidence of prior infection. There was no difference in the proportion of infection-naïve patients who seroconverted by vaccine type, but median anti-S antibody titres were higher post-BNT162b2 compared with ChAdOx1; 462(152-1171) and 78(20-213) BAU/ml respectively, p<0.001.  Concomitant immunosuppressant use was a risk factor for non-response, OR 0.12[95% CI 0.05-0.25] p<0.001.  Post-V3 (all BNT162b2), median anti-S antibody titres remained higher in those receiving BNT162b2 versus ChAdOx1 as primary doses; 2756(187-1246) and 1250(439-2635) BAU/ml respectively, p=0.003.Anti-S antibodies waned over time. Hierarchical levels of anti-S post-V2 predicted risk of infection; patients with no/low anti-S being at highest risk. VE for preventing infection, hospitalisation and death was 53% (95% CI 6-75), 77% (95% CI 30-92) and 93% (95% CI 59-99) respectively, with no difference seen by vaccine type.

Interpretation

Serum anti-S concentrations predict risk of breakthrough infection. Anti-S responses vary dependent upon clinical features, infection history and vaccine type. Monitoring of serological responses may enable individualised approaches to vaccine boosters in at risk populations.

Funding

National Institute for Health Research (NIHR) Biomedical Research Centre based at Imperial College Healthcare NHS Trust and Imperial College London.

Protease inhibitor plasma concentrations associate with COVID-19 infection

Protease inhibitors influence a range of innate immunity and inflammatory pathways. We quantified plasma concentrations of key anti-inflammatory protease inhibitors in chronic haemodialysis patients with coronavirus disease 2019 (COVID-19). The samples were collected early in the disease course to determine whether plasma protease inhibitor levels associated with the presence and severity of COVID-19. We used antibody-based immunoassays to measure plasma concentrations of C1 esterase inhibitor, alpha2-macroglobulin, antithrombin and inter-alpha-inhibitor heavy chain 4 (ITIH4) in 100 serial samples from 27 haemodialysis patients with COVID-19. ITIH4 was tested in two assays, one measuring intact ITIH4 and another also detecting any fragmented ITIH4 (total ITIH4). Control cohorts were 32 haemodialysis patients without COVID-19 and 32 healthy controls. We compared protease inhibitor concentration based on current and future COVID-19 severity and with C-reactive protein. Results were adjusted for repeated measures and multiple comparisons. Analysis of all available samples demonstrated lower plasma C1 esterase inhibitor and α2M and higher total ITIH4 in COVID-19 compared with dialysis controls. These differences were also seen in the first sample collected after COVID-19 diagnosis, a median of 4 days from diagnostic swab. Plasma ITIH4 levels were higher in severe than the non-severe COVID-19. Serum C-reactive protein correlated positively with plasma levels of antithrombin, intact ITIH4 and total ITIH4. In conclusion, plasma protease inhibitor concentrations are altered in COVID-19.

Longevity of SARS-CoV-2 immune responses in hemodialysis patients and protection against reinfection

Patients with end stage kidney disease receiving in-center hemodialysis (ICHD) have had high rates of SARS-CoV-2 infection. Following infection, patients receiving ICHD frequently develop circulating antibodies to SARS-CoV-2, even with asymptomatic infection. Here, we investigated the durability and functionality of the immune responses to SARS-CoV-2 infection in patients receiving ICHD. Three hundred and fifty-six such patients were longitudinally screened for SARS-CoV-2 antibodies and underwent routine PCR-testing for symptomatic and asymptomatic infection. Patients were regularly screened for nucleocapsid protein (anti-NP) and receptor binding domain (anti-RBD) antibodies, and those who became seronegative at six months were screened for SARS-CoV-2 specific T-cell responses. One hundred and twenty-nine (36.2%) patients had detectable antibody to anti-NP at time zero, of whom 127 also had detectable anti-RBD. Significantly, at six months, 71/111 (64.0%) and 99/116 (85.3%) remained anti-NP and anti-RBD seropositive, respectively. For patients who retained antibody, both anti-NP and anti-RBD levels were reduced significantly after six months. Eleven patients who were anti-NP seropositive at time zero, had no detectable antibody at six months; of whom eight were found to have SARS-CoV-2 antigen specific T cell responses. Independent of antibody status at six months, patients with baseline positive SARS-CoV-2 serology were significantly less likely to have PCR confirmed infection over the following six months. Thus, patients receiving ICHD mount durable immune responses six months post SARS-CoV-2 infection, with fewer than 3% of patients showing no evidence of humoral or cellular immunity.

42 Is Mitochondrial Function Measured by 31P Magnetic Resonance Spectroscopy Associated with Physical Performance in Older People with Functional Impairment?

Background

Mitochondrial dysfunction has been proposed as a therapeutic target to improve muscle strength and endurance, but the contribution that mitochondrial dysfunction makes to impaired skeletal muscle performance in older people remains unclear. We studied the relationship between phosphocreatine recovery rate (a measure of skeletal muscle mitochondrial function) and physical performance in older people.

Methods

We analysed data from the Allopurinol in Functional Impairment (ALFIE) trial. Participants aged 65 and over, who were unable to walk 400 m in six minutes, underwent 31P magnetic resonance spectroscopy of the calf after exercise at baseline and at 20 weeks follow up. The phosphocreatine recovery half-life time (t-half) was derived as a measure of mitochondrial function. Participants also undertook the 6-minute walk distance, the Short Physical Performance Battery test (SPPB), and had muscle mass measured using bio-impedance analysis. Bivariate correlations and multivariable regression analyses were conducted to determine associations between t-half and baseline factors.

Results

One hundred and seventeen people underwent baseline 31P magnetic resonance spectroscopy, mean age 80.4 years (SD 6.0); 56 (48%) were female. Mean 6-minute walk was 291 m (SD 80) and mean SPPB score was 8.4 (SD 1.9). T-half was significantly correlated with SPPB score (r = 0.22, p = 0.02) but not with 6-minute walk distance (r = 0.10, p = 0.29). In multivariable linear regression, muscle mass and weight, but not t-half, were independently associated with SPPB score and with 6-minute walk distance. The change in t-half between baseline and 20 weeks was not significantly associated with the change in SPPB (r = 0.03, p = 0.79) or with the change in 6-minute walk distance (r = −0.11, p = 0.28).

Conclusion

Muscle mass, but not phosphocreatine recovery time, was associated with Short Physical Performance Battery score and 6-minute walk distance in this cohort of older people with functional impairment.

Longitudinal proteomic profiling of dialysis patients with COVID-19 reveals markers of severity and predictors of death

End-stage kidney disease (ESKD) patients are at high risk of severe COVID-19. We measured 436 circulating proteins in serial blood samples from hospitalised and non-hospitalised ESKD patients with COVID-19 (n = 256 samples from 55 patients). Comparison to 51 non-infected patients revealed 221 differentially expressed proteins, with consistent results in a separate subcohort of 46 COVID-19 patients. Two hundred and three proteins were associated with clinical severity, including IL6, markers of monocyte recruitment (e.g. CCL2, CCL7), neutrophil activation (e.g. proteinase-3), and epithelial injury (e.g. KRT19). Machine-learning identified predictors of severity including IL18BP, CTSD, GDF15, and KRT19. Survival analysis with joint models revealed 69 predictors of death. Longitudinal modelling with linear mixed models uncovered 32 proteins displaying different temporal profiles in severe versus non-severe disease, including integrins and adhesion molecules. These data implicate epithelial damage, innate immune activation, and leucocyte-endothelial interactions in the pathology of severe COVID-19 and provide a resource for identifying drug targets.

Plasma Lectin Pathway Complement Proteins in Patients With COVID-19 and Renal Disease

We do not understand why non-white ethnicity and chronic kidney disease increase susceptibility to COVID-19. The lectin pathway of complement activation is a key contributor to innate immunity and inflammation. Concentrations of plasma lectin pathway proteins influence pathway activity and vary with ethnicity. We measured circulating lectin proteins in a multi-ethnic cohort of chronic kidney disease patients with and without COVID19 infection to determine if lectin pathway activation was contributing to COVID19 severity. We measured 11 lectin proteins in serial samples from a cohort of 33 patients with chronic kidney impairment and COVID19. Controls were single plasma samples from 32 patients on dialysis and 32 healthy individuals. We demonstrated multiple associations between recognition molecules and associated proteases of the lectin pathway and COVID-19, including COVID-19 severity. Some of these associations were unique to patients of Asian and White ethnicity. Our novel findings demonstrate that COVID19 infection alters the concentration of plasma lectin proteins and some of these changes were linked to ethnicity. This suggests a role for the lectin pathway in the host response to COVID-19 and suggest that variability within this pathway may contribute to ethnicity-associated differences in susceptibility to severe COVID-19.

Persistence of arctic-alpine flora during 24,000 years of environmental change in the Polar Urals

Plants adapted to extreme conditions can be at high risk from climate change; arctic-alpine plants, in particular, could "run out of space" as they are out-competed by expansion of woody vegetation. Mountain regions could potentially provide safe sites for arctic-alpine plants in a warmer climate, but empirical evidence is fragmentary. Here we present a 24,000-year record of species persistence based on sedimentary ancient DNA (sedaDNA) from Lake Bolshoye Shchuchye (Polar Urals). We provide robust evidence of long-term persistence of arctic-alpine plants through large-magnitude climate changes but document a decline in their diversity during a past expansion of woody vegetation. Nevertheless, most of the plants that were present during the last glacial interval, including all of the arctic-alpines, are still found in the region today. This underlines the conservation significance of mountain landscapes via their provision of a range of habitats that confer resilience to climate change, particularly for arctic-alpine taxa.

BRCA1 Attenuates Progesterone Effects on Proliferation and NFκB Activation in Normal Human Mammary Epithelial Cells

Germline mutations in the breast cancer susceptibility gene BRCA1, encoding a tumor suppressor protein, greatly enhance the risk of breast and ovarian cancer. This tissue-specificity implicates the role of ovarian hormones. Indeed, BRCA1 has been demonstrated to regulate the signalling axis of the hormone, progesterone, and its receptor, the progesterone receptor (PR), and progesterone action has been implicated in BRCA1-related tumorigenesis. BRCA1 also plays important roles in oxidative stress and activating nuclear factor kappaB (NFκB) signalling pathways. Like wildtype BRCA1 function, PR signalling has also been shown to inhibit NFκB activation. Although PR and BRCA1 networks are known to interact, their interaction at the level of NFκB activation in the human breast is not understood. This study investigates the effect of reduced BRCA1 expression on proliferation and NFκB activation in human breast cells, and the impact of progesterone on these effects. The major findings are that: 1) Reduced BRCA1 levels inhibit cell growth in normal human mammary cells and breast cancer cells; 2) Reduced BRCA1 levels stimulated inflammatory targets and NFκB activity in normal human mammary cells; 3) Wildtype BRCA1 inhibited the pro-proliferative effects of progesterone in normal mammary epithelial cells, and; 4) Progesterone attenuated BRCA1-mediated NFκB activation in normal human mammary cells. These data have important implications for our understanding of progesterone action in BRCA1 mutation carriers, and how inhibition of this action may potentially delay tumorigenesis or impart a more favourable prognosis.

Progesterone and estrogen receptors segregate into different cell subpopulations in the normal human breast

Progesterone is critical in normal breast development and its synthetic derivatives are emerging as major drivers of breast cancer risk. The recent demonstration that progesterone regulates the stem cell compartment in the murine mammary gland, despite the absence of progesterone receptor (PR) in mammary stem cells, highlights the fact that PR distribution in progenitor cell subsets in the human breast remains to be conclusively shown. By utilising two independent cell sorting strategies to fractionate cells into distinct subpopulations enriched for different cell lineage characteristics, we have demonstrated a consistent enrichment of PR transcripts, relative to estrogen receptor transcripts, in the bipotent progenitor subfraction in the normal human breast. We have also shown co-expression of both steroid hormone receptors with basal markers in a subset of human breast cells, and finally we have demonstrated that PR+ bipotent progenitor cells are estrogen-insensitive, and that estrogen regulates PR in mature luminal cells only.

The antiproliferative effects of progestins in T47D breast cancer cells are tempered by progestin induction of the ETS transcription factor Elf5

Prolactin and progesterone act together to regulate mammary alveolar development, and both hormones have been implicated in breast cancer initiation and progression. Here we show that Elf5, a prolactin-induced ETS transcription factor that specifies the mammary secretory cell lineage, is also induced by progestins in breast cancer cells via a direct mechanism. To define the transcriptional response to progestin elicited via Elf5, we made an inducible Elf5 short hairpin-RNA knock-down model in T47D breast cancer cells and used it to prevent the progestin-induction of Elf5. Functional analysis of Affymetrix gene expression data using Gene Ontologies and Gene Set Enrichment Analysis showed enhancement of the progestin effects on cell cycle gene expression. Cell proliferation assays showed a more efficacious progestin-induced growth arrest when Elf5 was kept at baseline levels. These results showed that progestin induction of Elf5 expression tempered the antiproliferative effects of progestins in T47D cells, providing a further mechanistic link between prolactin and progestin in the regulation of mammary cell phenotype.

Imatinib disposition and ABCB1 (MDR1, P-glycoprotein) genotype

The aim of this study was to explore the impact of individual variation in drug elimination on imatinib disposition. Twenty-two patients with gastrointestinal stromal tumor or chronic myeloid leukemia initially received imatinib 600 mg daily with dosage subsequently toxicity adjusted. Pharmacokinetic parameters on day 1 and at steady-state were compared with elimination phenotype and single-nucleotide polymorphisms of CYP3A5 and ABCB1. A fivefold variation in estimated imatinib clearance (CL/F) was present on day 1 and mean CL/F had fallen by 26% at steady state. This reduction in imatinib CL/F was associated with ABCB1 genotype, being least apparent in thymidine homozygotes at the 1236T>C, 2677G>T/A and 3435C>T loci. Toxicity-related dose reduction also tended to be less common in these individuals. ABCB1 genotype was associated with steady-state CL/F due to an apparent genotype-specific influence of imatinib on elimination. Further evaluation of ABCB1 genotype and imatinib dosage is warranted.

Progesterone receptor isoforms in normal and malignant breast

Progesterone is an essential regulator of normal female reproductive function, yet recent studies on the use of progestins in hormone replacement therapy have clearly implicated progestins in breast cancer development, a disease initiated early in life at a time of frequent exposure to cycling ovarian hormones. The effects of progesterone are mediated by two distinct nuclear receptor proteins, PRA and PRB. In normal breast PRA and PRB are co-expressed at similar levels in luminal epithelial cells, suggesting that both proteins are required to mediate physiologically relevant progesterone signalling. However, early in breast carcinogenesis PRA:PRB expression is disrupted, resulting in frequent predominance of one isoform. Unbalanced expression of PRA and PRB results in altered hormonal response and aberrant targeting of genes that are not normally progestin-regulated, principally those involved in morphological changes and disruptions of the actin cytoskeleton, and in migration. Movement of PR into discrete nuclear domains, or foci, is a critical step in normal PR transcriptional activity that appears to be aberrant in cancers and likely related to alterations in nuclear morphology, gene expression and cell function associated with tumour cells. Given that exogenous progestins are consumed by millions of women worldwide in the form of hormone replacement therapy and oral contraceptives, it is vital to better understand the mechanisms of progesterone action in the breast.

Mapping loss of heterozygosity in normal human breast cells from BRCA1/2 carriers

We have studied loss of heterozygosity at the BRCA1 and BRCA2 loci in 992 normal cell clones derived from topographically defined areas of normal tissue in four samples from BRCA1/BRCA2 mutation carriers. The frequency of loss of heterozygosity in the clones was low (1.01%), but it was found in all four samples, whether or not a tumour was present. Topographical mapping revealed that the genetic changes were clustered in some breast samples. Our study confirms the previous finding that a field of genetic instability can exist around a tumour, suggesting that sufficient tissue must be removed at surgery to avoid local recurrence. We also demonstrate that such a field of genetic change can exist in morphologically normal tissue before a tumour develops and, for the first time, we demonstrate that the field is of a size greater than one terminal duct-lobular unit. The genetic changes are not identical, however, which suggests that genetic instability in these regions may play an early role in tumour development. We also confirm and extend our original observation of loss of the wild-type BRCA1 allele in some clones, and loss of the mutant allele in others, demonstrating that loss of either allele is a stochastic event.

Tamoxifen treatment promotes phosphorylation of the adhesion molecules, p130Cas/BCAR1, FAK and Src, via an adhesion-dependent pathway

Reports that the adhesion-associated molecule p130Cas/BCAR1 promotes resistance to tamoxifen suggested that adhesion-mediated signalling may be altered by tamoxifen treatment. We find that p130Cas/BCAR1 phosphorylation is enhanced in tamoxifen-treated estrogen receptor (ER)-positive MCF-7 breast cancer cells. The effects of estrogen and tamoxifen were assessed independently and in combination, and the results demonstrate that tamoxifen antagonizes estrogen regulation of p130Cas/BCAR1 phosphorylation. Phosphorylation correlates with tamoxifen ER antagonist effects, as phosphorylation effects are replicated by the pure antiestrogen ICI 182, 780. Correspondingly, phosphorylation is not changed in ER-negative cells exposed to tamoxifen. We show that deletion of the p130Cas/BCAR1 substrate domain substantially reduces tamoxifen-induced phosphorylation of p130Cas/BCAR1 and confers enhanced sensitivity to tamoxifen. P130Cas/BCAR1 forms a phosphorylation-dependent signalling complex with focal adhesion kinase (FAK) and Src kinase that promotes adhesion-mediated cell survival. Therefore, we examined the kinetics of p130Cas/BCAR1, Src and FAK phosphorylation over a 14-day time course and find sustained phosphorylation of these molecules after 7 days exposure to tamoxifen. Inhibition of Src kinase is shown to reduce tamoxifen-promoted p130Cas/BCAR1 phosphorylation and reduce cell viability. Stimulation of the Src/FAK/p130Cas/BCAR1 adhesion signalling pathway in tamoxifen-treated MCF-7 cells does not cause increased migration; however, there is Src-dependent phosphorylation of the cell survival molecule Akt. Correspondingly, Akt inhibition reduces cell viability in cells treated with tamoxifen. We propose that prolonged activation of adhesion-dependent signalling may confer a survival advantage in response to additional cellular insults or alternatively, may poise cells to develop a migratory phenotype in response to additional cellular cues.

Histopathologic indicators of breast cancer biology: insights from population mammographic screening

Histopathologic features of breast cancer such as tumour size, grade and axillary lymph node (LN) status variably reflect tumour biology and time. Recent evidence suggests that the biological character of breast cancer is established at an early stage and has a major impact on clinical course. The aim of this study was to distinguish the impact of biology on breast cancer histopathology by comparing features of breast cancers diagnosed following population mammographic screening with prevalent vs incident detection and screening interval. Central histopathology review data from 1147 cases of ductal in situ and/or invasive breast cancer were examined. Size, grade and LN status of invasive cancers were positively correlated (P<0.001). Prevalent invasive cancers were larger (P<0.001) and more likely to be LN positive (P=0.02) than incident cases, but grade was not associated with screening episode (P=0.7). Screening interval for incident cancers was positively associated with invasive cancer size (P=0.05) and LN status (P=0.002) but not grade (P=0.1). Together, these data indicate that biology and time both impact on size and LN status of invasive breast cancer, but grade reflects biology alone. In view of the clinical importance of breast cancer biology, grade as its most direct indicator assumes particular significance.

Effect of Progesterone Receptor A Predominance on Breast Cancer Cell Migration into Bone Marrow Fibroblasts

Women exposed to exogenous progesterone have increased breast cancer risk, but the mechanisms of progesterone involvement in breast cancer development are unknown. In human breast and endometrium, progesterone receptor (PR) isoform expression is disrupted in premalignant lesions and predominance of one isoform, usually PRA, in invasive cancers is associated with poorer prognosis. Disrupted PR isoform expression results in disrupted progestin regulation of cell morphology, including rounded morphology and decreased adherence of cells to tissue culture flasks. The purpose of this study was to test the hypothesis that predominance of PRA affects the interaction of breast cancer cells with a physiologically relevant stromal tissue, bone marrow stroma. T-47D breast cancer cells demonstrated the ability to migrate into bone marrow fibroblasts and this was inhibited by progestin treatment. The antiprogestin RU38486 abrogated the progestin effect on migration, demonstrating that it was PR-mediated. In cells expressing a predominance of PRA, after induction of a stably integrated inducible PRA construct, the ability of progestin to inhibit breast cancer cell migration was lost. A number of integrins were progestin regulated in T-47D cells, but there was no difference in the progestin effect in cells with PRA predominance, nor were the levels of focal adhesion proteins altered in these cells. This suggested that the lack of inhibition by progestin of breast cancer cell migration in cells with PRA predominance was not mediated by PRA effects on the membrane components of the adherens junctions. In summary, this study has shown that PRA predominance has a striking functional effect on breast cancer cell migration into stromal layers. PRA predominance may render breast cancer cells relatively resistant to the inhibitory effects of progestins and one consequence of this may be increased invasion of stroma. If borne out in vivo, these findings suggest that tumours with PRA predominance may be predisposed to cancer progression and this may signal a poorer prognosis in patients.

Cytoskeletal responsiveness to progestins is dependent on progesterone receptor A levels

Changes in the cell cytoskeleton occur in cell transformation and recent data suggest the involvement of ovarian hormones, which are implicated in cancer development and progression. In human breast and endometrial tumors, there is disrupted expression of progesterone receptor (PR) isoforms and predominance of one isoform, usually PRA. PRA predominance is an early event in carcinogenesis, and in cancers is associated with poor clinical features. Overexpression of PRA in vitro causes altered progestin regulation of cell morphology, suggesting that PRA overexpression may provoke deleterious changes in cell functioning. This study aimed to identify pathways of cytoskeleton regulation responsive to progestins and to determine whether these are perturbed when PRA is overexpressed to the levels seen in cancers. Progestin treatment of PR-positive breast cancer cells caused increased cell surface area whereas after induction of a stably integrated PRA construct, cells became rounded and the cell surface was decreased. The effect of PRA induction on cell rounding was reversed by the anti-progestin RU38486. Altered tropomyosin (Tm) isoforms were implicated in these morphological differences, as there was a PRA-mediated alteration in Tm5 isoform levels, and transfection of Tm5a mimicked progestin-mediated cell rounding in PRA-overexpressing cells. Ezrin was redistributed from the membrane to cytoplasmic locations in the presence of progestin, and discrete focal localization was evident in cells with PRA predominance. Progestin effects on the cytoskeleton in PRA-overexpressing cells provide evidence for novel endocrine regulation of aspects of actin microfilament composition, suggesting that changes in the cytoskeleton known to be associated with cancer development and progression may be regulated in part by altered PRA expression which develops early in carcinogenesis.

Loss of co-ordinate expression of progesterone receptors A and B is an early event in breast carcinogenesis

Progesterone receptor (PR) mediates the effects of progesterone in mammary tissues and plays a crucial role in normal breast development and in breast cancer. PR proteins are expressed as two isoforms, PRA and PRB, that have different capacities to activate target genes, yet it is unknown whether progesterone action in normal and malignant breast is mediated by PRA and/or PRB. This study determines the relative expression of PRA and PRB in normal breast and in benign, premalignant and malignant archival breast lesions by dual immunofluorescent histochemistry. In normal breast and in proliferative disease without atypia (PDWA) PRA and PRB were co-expressed within the same cells in comparable amounts, implicating both isoforms in progesterone action. In atypical lesions, however, there was a significant increase in predominant expression of PRA or PRB, with lesion progression from the normal state to malignancy. PR isoform predominance, especially PRA predominance, was evident in a high proportion of ductal carcinomas in situ (DCIS) and invasive breast lesions. In the normal breast and in PDWA, the relative expression of PRA and PRB in adjacent cells was homogenous. There was a significant increase in cell-to-cell heterogeneity of PR isoform expression in ADH and DCIS lesions and in the majority of breast cancers. Heterogeneous cell-to-cell expression of PR isoforms occurred prior to overall predominant expression of one isoform in premalignant breast lesions, demonstrating that loss of control of relative PRA:PRB expression is an early event in the development of breast cancer. PRA:PRB ratios within a breast lesion are likely to be important as both markers and effectors of tumor growth and development, and progressively aberrant PR isoform expression may play a role in the etiology of breast cancer.

Detection of progesterone receptor forms A and B by immunohistochemical analysis

AIM

The measurement of progesterone receptors (PR) is recommended as part of the clinical management of breast and endometrial cancers, and immunohistochemistry on formalin fixed tissue is now the method of choice. PR is expressed as two isoforms, PRA and PRB, and although both these proteins are expressed in hormone dependent cancers, there is evidence that a large proportion of tumours express a predominance of one isoform. Therefore, it is essential to document the individual detection of PRA and PRB by the presently available anti-PR antibodies. The aim of this study is to investigate the detection of PR isoforms A and B in formalin fixed, paraffin wax embedded cell lines and tissue sections by immunohistochemistry, using a panel of commercial and in house antibodies to human PR.

METHODS

PR negative cell lines stably transfected to express only PRA (MCF-7Mll/PRA) or PRB (MDA-MB-231/PRB), and tissue sections of human breast carcinoma and normal endometrium were stained using an immunoperoxidase method. A panel of primary PR specific antibodies was evaluated for ability to detect both PRA and PRB proteins, and for intensity and distribution of positive staining under optimal conditions.

RESULTS

Of the 11 antibodies assessed, only four recognised PRA and PRB similarly. Six recognised PRA proteins but were unable to detect PRB expression in the cell lines expressing only PRA or PRB. In tissues expressing high amounts of PRA and PRB, all antibodies tested demonstrated positive PR staining. However, in tissues expressing a predominance of PRB, differential staining patterns were observed, with variations in staining intensity and in the proportion of cells positive for PR.

CONCLUSIONS

Most PR specific antibodies tested failed to detect PRB in formalin fixed tissue by immunohistochemical techniques, despite their ability to do so by immunoblot analysis. These observations suggest that there are conformational differences between PRA and PRB that mask epitopes on the PRB protein recognised by most anti-PR antibodies. The selection of antibodies that recognise both PRB and PRA in formalin fixed tissue is essential for the accurate evaluation of PR positivity in clinical specimens.

Relative expression of progesterone receptors A and B in endometrioid cancers of the endometrium

The nuclear receptor for the female hormone progesterone (PR) is widely expressed in uterine cancer. PR is expressed as two proteins (PRA and PRB) with different functions, and in vitro evidence reveals PRA to inhibit PRB function, so the cellular ratio of PRA:PRB is likely to be an important determinant of progesterone action. The relative expression of PRA and B and their involvement in the pathogenesis of endometrial cancer is not known. The aims of this study were to determine PRA and B expression by dual immunofluorescent histochemistry in endometrial adenocarcinomas compared with expression in normal and hyperplastic glands, and to correlate expression in tumors with clinical features including grade. Significantly lower PR levels were found in tumors compared with normal glands and areas of complex atypical hyperplasia within the same specimen. The normal glands expressed both of the isoforms at similar levels, whereas there was increased predominance of one isoform in hyperplastic areas and in tumors, which suggested that the loss of coordinated expression of PR isoforms was an early event in tumor progression. The majority of tumors [27 (58%) of 46] expressed only one PR isoform, and the proportion expressing either PRA or B was the same [14 (30%) of 46, and 13 (28%) of 46, respectively]. One-half of all tumors ([23 (50%) of 46] expressed either PRA only or a predominance of PRA, and a few tumors [10 (22%) of 46] expressed comparable levels of PRA and B. Similar levels of PRA and B were noted only in FIGO grade 1 tumors, whereas higher grades (2 and 3) were associated with a predominance of one isoform. In summary, expression of only one PR isoform was common in endometrial cancers, which indicates that the decreased PR levels observed in these cancers arise from the loss of one PR isoform. Expression of a single PR isoform was associated with higher clinical grade, which suggests a relationship between the loss of PR isoform expression and features of poorer prognosis. Disruption of relative PR isoform expression was observed in complex atypical hyperplasia, which suggests that early alterations in the ratio of PRA:PRB may precede and/or be implicated in the development of endometrial adenocarcinoma. Alterations in the ratio of PR isoform expression are likely to cause disordered regulation of target genes, resulting in altered progestin action in the uterus, and this may be involved in the pathogenesis of endometrial cancer.

Professional and organizational learning: analysing the relationship with the development of practice

BACKGROUND

Organizational and professional learning are interrelated processes that underpin the contemporary drive for a quality evidence-based delivery of health care in the United Kingdom (UK).

DESIGN

A soft systems methodology was used to explore the pervasiveness of practice developments. Three case study sites were identified using matrix sampling and data collected through 29 individual interviews and two focus group interviews, with the interviews augmented with a tool designed to maximize analysis of the processes of developing practice.

FINDINGS

The resultant model of developing health care practice includes three processes: using and creating knowledge, understanding and practice of patient care, and effecting development. The whole model was underpinned by professional and organizational learning in which 'expert thinkers' engaged in double loop learning to reconceptualize care rather than just perpetuate existing patterns of care delivery.

Histone deacetylase inhibitors decrease proliferation and modulate cell cycle gene expression in normal mammary epithelial cells

Full-term pregnancy early in reproductive life is protective against breast cancer in women. The protective effects of parity have variously been attributed to the differentiation that accompanies pregnancy and lactation, alterations in ovarian hormone receptor levels, and altered sensitivity to ovarian hormones. Butyrate, a short-chain fatty acid, induces differentiation in breast cancer cell lines and decreases hormone receptor expression. Butyrate also inhibits proliferation in breast cancer cell lines and modulates expression of key cell cycle-regulatory proteins including cyclin D1. Given these properties, butyrate could be considered a promising agent for breast cancer prevention. Therefore, this study aimed to determine the effects of butyrate on normal human breast epithelial cells and to compare the effects of two stable butyrate derivatives with more favorable pharmacological properties: phenylacetate and its p.o. active precursor phenylbutyrate. Treatment with each agent resulted in concentration-dependent growth inhibition in a normal breast epithelial cell line and two breast cancer cell lines (MCF-7 and MDA-MB-231). Phenylbutyrate and butyrate inhibited proliferation to a similar extent, but phenylacetate was less effective in all of the cell lines. All three of the agents induced differentiation (accumulation of lipid droplets) in normal as well as in breast cancer cells and caused a decrease in estrogen receptor (ER) mRNA in MCF-7 cells. The butyrates decreased expression of cyclin D1, increased expression of p21(Waf1/Cip1), and hypophosphorylated pRB in the normal mammary epithelial cells. The effects on cyclin D1 expression correlated with the effects on cell proliferation, which suggests that modulation of cyclin D1 expression may underpin the antiproliferative effects of butyrates. We have shown that butyrate and butyrate-like agents are able to decrease proliferation and induce differentiation in normal breast cells as well as in malignant breast cells (ER-positive and ER-negative) and, as such, may be considered as candidate chemopreventative agents for women at high risk of developing breast cancer.

Hearing the voices of children with chronic illness

This qualitative study has aimed to explore children's, parents' and health professionals' experience of childhood chronic illness. Seven families and their professional carers participated in semistrucured interviews. The children's interviews were augmented with a 'drawing' technique. A grounded theory approach facilitated data collection and analysis. This paper debates the perceived passivity of the voice of children in health care and research and illustrates data collection methods that seek to give children and other disadvantaged groups a voice. The children who participated in this study are described as competent interpreters of their world.

The hD52 (TPD52) gene is a candidate target gene for events resulting in increased 8q21 copy number in human breast carcinoma

Chromosome band 8q21 is frequently overrepresented in human cancer, but to date no 8q21 target gene has been proposed. The hD52 (TPD52) gene is of potential significance in breast and other cancers due to its location and expression pattern. Fine mapping of hD52 placed this locus within the peak of the 8q21 amplicon delineated in the SK-BR-3 breast carcinoma cell line, and a positive association between hD52 gene dosage and transcript levels was subsequently demonstrated in four breast carcinoma cell lines, including SK-BR-3. Increased copy number (ICN) was measured using Southern blot analyses in 3/32 human breast carcinomas at hD52, and the related hD54 gene in 20q13.2-q13.3. Subsequent immunohistochemical analysis of hD52 expression in 19 breast carcinomas with varying hD52 gene dosages demonstrated a significant positive association between hD52 dosage and hD52 expression using a Spearman rank correlation coefficient (r(s) = 0.573, alpha = 0.01) and a Wilcoxon rank-sum test (alpha = 0.05). On the basis of its map location and expression pattern in breast carcinoma, we therefore propose hD52 as a candidate target gene at chromosome band 8q21.

Heterogeneity of progesterone receptors A and B expression in human endometrial glands and stroma

The human progesterone receptor (PR) is expressed as two isoforms, PRA and PRB, which function as ligand-activated transcription factors. In-vitro studies suggest that the isoforms differ functionally and that their relative expression in a target cell may determine the nature and magnitude of response to progesterone. We have shown recently that PRA and PRB are co-expressed in target cells of the human endometrium. The purpose of this study was to investigate the homogeneity of expression of PRA and PRB in target cells of the human uterus throughout the menstrual cycle. In the functionalis, PRA and PRB were expressed in comparable levels in glandular epithelium during the proliferative phase of the cycle, whereas there was persistence of PRB but not PRA in the glands during mid-secretory phase. In the stroma, there was predominance of the PRA isoform throughout the cycle. There was remarkable homogeneity in the relative expression of PRA and PRB in adjacent cells within the same tissue compartment, suggesting that the mechanisms regulating relative PR isoform expression are similarly active in these cells. By contrast, heterogeneity between glands was observed under some circumstances in the functionalis of the endometrium, suggesting PR isoform down-regulation by progesterone to be asynchronous. Heterogeneity was also seen between the glands of the basalis and functionalis of the endometrium implying region-specific responses to hormonal stimuli. This study demonstrates adjacent cell homogeneity in the relative expression of PRA and PRB in normal human endometrial tissue and a differential response to ovarian steroid hormones between cell types and between different regions within the same tissue.

Localization of the delta-opioid receptor and dopamine transporter in the nucleus accumbens shell: implications for opiate and psychostimulant cross-sensitization

Opiate- and psychostimulant-induced modulation of dopamine transmission in the nucleus accumbens shell (AcbSh) is thought to play a key role in their potent reinforcing and locomotor effects. To investigate the cellular basis for potential functional interactions involving opiates active at the delta-opioid receptor (DOR) and psychostimulants that bind selectively to the dopamine transporter (DAT), we examined the electron microscopic localization of their respective antisera in rat AcbSh. DOR immunoperoxidase labeling was seen primarily, and DAT immunogold particles exclusively, in axon terminals. In these terminals, DOR immunoreactivity was prominently associated with discrete segments of the plasma membrane and the membranes of nearby small synaptic and large dense core vesicles. DAT immunogold particles were almost exclusively distributed along nonsynaptic axonal plasma membranes. Thirty-nine percent DOR-labeled profiles (221/566) either apposed DAT-immunoreactive terminals or also contained DAT. Of these 221 DOR-labeled profiles, 13% were axon terminals containing DAT and 15% were dendritic spines apposed to DAT-immunoreactive terminals. In contrast, 70% were morphologically heterogeneous axon terminals and small axons apposed to DAT-immunoreactive terminals. Our results indicate that DOR agonists in the AcbSh can directly modulate the release of dopamine, as well as postsynaptic responses in spiny neurons that receive dopaminergic input, but act principally to control the presynaptic secretion of other neurotransmitters whose release may influence or be influenced by extracellular dopamine. Thus, while opiates and psychostimulants mainly have differential sites of action, cross-sensitization of their addictive properties may occur through common neuronal targets.

Effect of overexpression of progesterone receptor A on endogenous progestin-sensitive endpoints in breast cancer cells

The human progesterone receptor (PR) is expressed as two isoforms, PRA and PRB, which differ in the N-terminal region and exhibit different activities in vitro, with PRA demonstrating dominant negative inhibitory effects on the activity of PRB and other nuclear receptors. PRA and PRB are expressed in target tissues at comparable levels although cells expressing a predominance of one isoform can be identified. In breast cancers, PRA is expressed at high levels in some tumors, and this may be associated with features of poorer prognosis. To investigate the role of PRA overexpression in PR-positive target cells, the effect of PRA induction on cell proliferation and expression of endogenous progestin-sensitive genes, SOX4 and fatty acid synthetase (FAS), was examined using PR-positive T-47D cell lines, which express a predominance of PRB, in which PRA could be increased 2- to 20-fold over basal levels. No effect of PRA induction was noted on cell proliferation, but marked changes in morphology, consistent with loss of adherent properties, were observed. Increases up to 4-fold in the relative PRA levels augmented progestin induction of SOX4 mRNA expression, and RU486 treatment revealed a progestin agonist effect. There was no consistent effect of PRA induction on progestin-mediated increases in FAS mRNA levels under these conditions. Clones with PRA:PRB ratios greater than 15 were associated with diminished progestin responses on both SOX4 and FAS mRNA expression. These data show that PRA overexpression is associated with alteration in adhesive properties in breast cancer cells and effects on endogenous progestin targets that were dependent on the cellular ratio of PRA:PRB. The results of this study are consistent with the view that PRA expression can fluctuate within a broad range in target cells without influencing the nature of progestin action on downstream targets, but that overexpression of PRA, such as is seen in a proportion of breast cancers, may be associated with inhibition of progestin action and features of poor prognosis.

Nursing older people: constructing need and care

As the population of the world 'ages', older people are increasingly viewed as a 'problem' whose needs challenge the resources of care services. However, this view is predicated on the negative and nihilistic attitudes that are held throughout society about older people and the effectiveness of therapeutic intervention. It is these pessimistic views which colour professional understandings of the needs of older people and the most appropriate ways of delivering care to meet those needs. However, any knowledge of need and care is a constructed story, and is limited by the knowledge base on which it rests. For example, western healthcare is dominated by an orientation to identified problems, the minimizing of physical risk or harm, and a reductionalist approach to problem solving. A social critical challenge to prevailing understandings of need and care produces a very different story about older age; one which emphasizes an individual's strengths and their family and community relationships. In exploring these issues in policy and practice two key areas are highlighted. One is the role of critical gerontology in challenging the stories of negativity about old age, and replacing these with positive stories that allow older people to retain their social purpose. The second key area is the need to address issues of older age at both a practice and policy level, and to understand the interrelationship between them.

Expression and hormonal regulation of the Sox4 gene in mouse female reproductive tissues

The SOX genes define a family of transcriptional regulators whose diverse patterns and tightly controlled temporal profiles of expression suggest that they play key roles in determination of cell fate during development. One of the family members, Sox4, is expressed in the gonads of adult mice, but expression in the reproductive tissues has not been studied. As previous studies in this laboratory had shown that the SOX4 gene was regulated by ovarian hormones in breast cancer cells, murine Sox4 expression was analyzed in the reproductive tissues of mice by Northern blot analysis and ribonuclease protection assays. Sox4 mRNA expression was detected in the uterus and, at a lower level, in the mammary glands of pubertal and adult mice. Expression was modulated in the uterus of intact mice at various stages of the estrous cycle and was reduced by estradiol treatment of ovariectomized mice. Progesterone treatment partially reversed the estradiol effect. Although no modulation of Sox4 expression in the mammary glands was detected by Northern blot analysis, further evaluation of Sox4 protein expression at a cellular level is required. No modulation of Sox4 levels was observed in the thymus. The results presented here suggest that expression of the Sox4 gene is under ovarian hormone control in the uterus and implicate Sox4 in the complex effects controlled by ovarian hormones in the female reproductive system.

Colocalization of progesterone receptors A and B by dual immunofluorescent histochemistry in human endometrium during the menstrual cycle

The human progesterone receptor (PR) is expressed as two isoforms, PRA and PRB, that function as ligand-activated transcription factors. In vitro studies suggest that the isoforms differ functionally and that the relative levels in a target cell may determine the nature and magnitude of response to progesterone. However, it is not known whether the two isoforms are normally coexpressed in vivo. To understand the functional significance of relative PR isoform expression in normal physiology, it is essential to determine whether PRA and PRB are coexpressed in the same cell. This study reports the development of a dual immunofluorescent staining technique to demonstrate PRA and PRB proteins by single cell analysis in the same tissue section of human endometrium during the menstrual cycle. PRA and PRB are coexpressed in target cells of the human uterus. In the glands, PRA and PRB were expressed before subnuclear vacuole formation and glycogenolysis, implicating both isoforms in this process, whereas persistence of PRB during the midsecretory phase suggested its significance in glandular secretion. In the stroma, the predominance of PRA throughout the cycle implicates this isoform in post-ovulatory progesterone-mediated events. These results support the view that PRA and PRB mediate distinct pathways of progesterone action in the glandular epithelium and stroma of the human uterus throughout the menstrual cycle.

Regulation of the expression and activity by progestins of a member of the SOX gene family of transcriptional modulators

The mammalian testis-determining gene Sry and the related Sox genes define a family of transcriptional regulators widely expressed during embryogenesis. Tightly controlled temporal profiles of expression are a feature of the Sox gene family and may be required for initiation of a cascade of gene expression, yet the molecular mechanisms that control Sox gene expression are unknown. We now show that human SOX4 is expressed in the normal breast and in breast cancer cells. In these cells SOX4 is a progesterone-regulated gene, the expression of which is increased by progestins, leading to a marked increase in SOX-mediated transcriptional activity. Treatment of T-47D breast cancer cells with the synthetic progestin ORG 2058 directly increased SOX4 transcription, resulting in a 4-fold increase in SOX4 mRNA levels within 4 h of treatment. No effect of ORG 2058 was noted on other SOX genes measured, nor were other hormone-regulated HMG box proteins detected in this system, suggesting that the observed ability of progestin to increase SOX mRNA expression was confined to SOX4. The increase in SOX4 transcription was reflected in increased SOX4 protein expression, as progestin treatment of T-47D cells transfected with a SOX-responsive reporter resulted in a marked increase in reporter gene expression. Progesterone is essential for normal development and differentiation of the female reproductive system, plays an essential role in regulating growth and differentiation of the mammary gland and is required for opposing the proliferative effects of estrogen in specific cell types. The detection of SOX4 expression in the normal and malignant breast and the demonstration that SOX4 expression is under progesterone control suggests that changes in SOX4 gene expression may play a role in commitment to the differentiated phenotype in the normal and malignant mammary gland.

N-methyl-D-aspartate receptor 1 in the caudate-putamen nucleus: ultrastructural localization and co-expression with sorcin, a 22,000 mol. wt calcium binding protein

Entry of calcium through N-methyl-D-aspartate-type glutamate receptors in the caudate-putamen nucleus is essential for normal motor activity, but can produce cytotoxicity with continued stimulation and subsequent release of intracellular calcium. To determine potential functional sites for N-methyl-D-aspartate receptor activation in this region, we examined the ultrastructural localization of the R1 subunit of the N-methyl-D-aspartate receptor (NMDAR1) in rat brain. In addition, we comparatively examined the localization of NMDAR1 and sorcin, a 22,000 mol. wt calcium binding protein present in certain striatal neurons and involved in calcium-induced calcium release. NMDAR1-like immunoreactivity was seen at synaptic and non-synaptic sites on neuronal plasma membranes. Of 1514 NMDAR1-labeled profiles, 62% were dendrites and dendritic spines and the remainder were mainly unmyelinated axons and axon terminals. Sorcin-like immunoreactivity was present in 39% of the profiles that contained NMDAR1 labeling, most (533/595) of which were dendrites and dendritic spines. Of 1807 sorcin-labeled profiles, 42% were identified, however, as small processes including spine necks and unmyelinated axons or axon terminals. These profiles also occasionally contained NMDAR1 or showed synaptic or appositional contacts with other NMDAR1-immunoreactive neurons. The results of this study suggest that in the caudate-putamen nucleus, activation of NMDA receptors permits calcium influx at plasmalemmal sites mainly on dendrites where sorcin may play a role in calcium-induced calcium release. The presence of sorcin in some, but not all NMDA-containing neurons in the caudate-putamen nucleus has potential implications for the known differential vulnerability of certain striatal neurons to excitotoxins.

Expression of the oestrogen responsive protein pS2 in human breast cancer

The trefoil peptide pS2 was discovered in a breast cancer cell line as a result of its oestrogen responsive character. The expression of pS2 in breast tumours in vivo is also likely to be an oestrogenic effect and as such, the presence of pS2 in oestrogen receptor positive breast cancer is evidence of an intact oestrogen response pathway and an indicator of putative hormone responsiveness. Consistent with this, clinical studies of breast cancer have revealed a correlation between pS2 expression and favourable tumour characteristics as well as response to endocrine therapy.

Coexpression of alternatively spliced estrogen and progesterone receptor transcripts in human breast cancer

Primary transcripts of the human estrogen receptor (ER) and progesterone receptor (PR) are subject to a number of alternative splicing events resulting in a range of variant messenger ribonucleic acid species in receptor-positive tissues. Despite in vitro demonstrations of a possible role for some of these variants in hormonal sensitivity, the clinical significance of this process is uncertain. In this study the coexpression of variant ER and PR transcripts has been documented by RT-PCR and Southern blot analysis in a series of receptor-positive breast tumors. In 35 ER-positive tumors, a common profile of variant ER transcripts was present, with all tumors containing the delta2ER and delta7ER, 94% containing the delta4ER, and 83% containing the delta5ER. In 25 of these cases, which were also PR positive, the most highly expressed PR variants, the delta4PR, delta6PR, and delta(4/2)PR, a transcript from which a 126-bp portion of PR exon 4 was deleted, were detected in over 90% of the cases. The alternatively spliced ER variants were expressed at higher relative levels than the PR species, which had mean levels of expression less than 10% that of wild-type PR. The most abundant species was the delta7ER, which was present at levels ranging from 29-83% of the wild type. There was no relationship between the level of delta7ER in individual tumors and the pattern of expression of the estrogen-responsive proteins PR and pS2. The common profile of alternatively spliced ER and PR transcripts in breast tumors means that this feature cannot be used as a discriminator of hormone responsiveness or other clinical end points. Further, the low level of expression of the majority of variant species calls into question their potential for impacting significantly on receptor function.

Family care-giving for people with dementia: some implications for policy and professional practice

The objective of this paper is to describe one study undertaken in the north of England which sought an understanding of family care-giving for people with dementia. Data were collected by interview and diary with 14 family carers, by questionnaire with 60 professional carers, and by interview and diary from nine case studies. Family carers were found to value their continuing relationship with the person with dementia. This emphasis on their relationship together influenced the contact which they had with professional carers. The implications of this research for policy and professional practice are explored through illumination of the tensions in professional responses to family carers.

Absence of progesterone receptor associated with secondary breast cancer in postmenopausal women

The relationship between expression of receptors for oestrogen and progesterone (ER and PR) and disease progression in breast cancer was investigated by comparing immunocytochemical determinations of ER and PR in fine needle aspirates from primary and secondary breast tumours. Rates of receptor expression were significantly higher in primary than in secondary lesions: for ER 63.3% (n = 689) compared with 45.3% (n = 223), and for PR 53.7% (n = 443) compared with 33.1% (n = 121). The effect of menopausal status was examined by subdividing the patient cohort into those over or under the age of 50 years. In both instances, ER expression in secondary tumours was relatively low; however, only postmenopausal patients had significantly lower rates of PR expression in secondary tumours. Consistent with this, an increase in the ER+PR- profile in secondary tumours compared with primary cases from postmenopausal patients was seen, and in a multivariate analysis, a specific absence of PR expression in secondary tumours was revealed. Comparison of ER and PR expression in simultaneously sampled primary tumours and lymph node metastases from the same patient showed that receptor expression was stable with progression to a metastatic site as results were concordant for ER in 92% (n = 88) and PR in 93.8% of cases (n = 65). These results suggest that absence of PR expression in primary breast cancer is associated with disease progression and may be a marker of an aggressive tumour phenotype.

Immunohistochemical detection of progesterone receptors in archival breast cancer

The progesterone receptor (PR) is an important marker of response to endocrine agents in breast cancer. Immunohistochemical demonstration of PR in formalin fixed tissue has previously proved difficult, and heat pretreatment is considered necessary to retrieve the antigen. There are few data on the effectiveness of autoclaving in unmasking PR, however, and it is not known whether all PR epitopes are equally unmasked. The objectives of this study were to compare the efficacy of autoclaving and microwaving to retrieve PR antigen in archival breast tumors, to determine whether there is an epitope-dependent variability in the pretreatment required, and to examine different slide types and adhesives to reduce the problem of section loss frequently associated with these procedures. Paraffin embedded sections were cut at 2 or 4 microm, mounted onto various slide types with or without the addition of adhesive, and heat pretreated prior to immunoperoxidase staining. Whereas PR immunoreactivity was clearly demonstrated in tissue after both autoclaving and microwaving, autoclaving produced a significantly stronger staining intensity under the conditions used in this study. The duration of autoclaving required to reveal PR fully differed for different epitopes examined. In the absence of heat pretreatment, PR was not detected. Section retention was improved by the use of adhesives and by cutting tissue at 2 microm. Maximum retention was obtained using positively charged slides coated with Mayer albumen adhesive. We conclude that for maximal tissue preservation autoclave pretreatment is the preferred method of PR antigen retrieval from archival breast tumors, that there is epitope-dependent variability in pretreatment required, and that section loss during this procedure can be minimized by choice of slide type, the use of adhesive, and by cutting sections at 2 microm.

Loss of nuclear BRCA1 expression in breast cancers is associated with a highly proliferative tumor phenotype

Recent studies have suggested that BRCA1-associated hereditary breast cancer may be a more aggressive form of disease than sporadic breast cancer. BRCA1-associated breast cancer has been reported to be significantly associated with grade 3 disease. Because grade 3 disease indicates a poor prognosis, this implies that women with a germ-line mutation in BRCA1 who develop breast cancer may have a poorer prognosis than those with sporadic disease. However, little is known about the association of BRCA1 expression with biological markers of prognosis. The present study examined the expression of BRCA1 in a total of 40 archival breast tumor specimens from three patient cohorts (sporadic, familial, and early onset breast cancer) to determine localization of the protein. Furthermore, BRCA1 staining was compared with expression of markers of tumor biology. We found that BRCA1 is generally located in the nucleus and the cytoplasm of normal and malignant breast tissue. Nuclear staining for BRCA1 was observed in most sporadic tumors, but nuclear BRCA1 was reduced or absent in the majority of familial and early onset breast tumors. Although no correlation was found between nuclear BRCA1 expression and estrogen and progesterone status, a significant inverse correlation was found between nuclear BRCA1 and expression of the proliferation marker Ki-67 (P = 0.01). Our findings suggest that tumors associated with a germ-line mutation in one of the breast cancer genes may be highly proliferative and support the view that loss of BRCA1 expression in breast tumors may lead to a more aggressive tumor phenotype.

Cellular sites for activation of delta-opioid receptors in the rat nucleus accumbens shell: relationship with Met5-enkephalin

The shell compartment of the nucleus accumbens (AcbSh) is prominently involved in the rewarding aspects of delta-opioid receptor (DOR) agonists, including one of its putative endogenous ligands, Met5-enkephalin (Enk). We examined the ultrastructural immunocytochemical localization of an antipeptide DOR antiserum and an antibody against Enk to determine the major cellular sites for DOR activation and the spatial relationship between DOR and Enk in this region. Sixty percent of DOR-immunoreactive profiles were axon terminals and small unmyelinated axons, whereas the remainder were mainly dendrites and dendritic spines. In axons and terminals, DOR labeling was distributed along plasma and vesicular membranes. DOR-containing terminals were mainly large and primarily formed symmetric synapses or occasionally asymmetric synapses. DOR immunoreactivity also was associated with terminals that were small and formed punctate symmetric or nonrecognizable synapses. Dual immunoperoxidase and immunogold labeling showed that 35% of DOR-labeled axons apposed other terminals that contained Enk. In addition, 25% of the DOR-labeled terminals contained Enk. Thirty-five percent of DOR labeling was observed within dendrites and dendritic spines. DOR-labeled spines showed intense immunoreactivity within asymmetric postsynaptic junctions, which were formed by terminals that lacked Enk immunoreactivity. DOR-labeled spines, however, were apposed to Enk-containing terminals in 13% of all associations between dually labeled profiles. These results provide ultrastructural evidence that activation of DOR in the AcbSh is primarily involved in modulating the presynaptic release of mainly inhibitory, but also excitatory, neurotransmitters. These data also suggest that DOR plays a role in determining the postsynaptic response to excitatory afferents.

Characterization of a truncated progesterone receptor protein in breast tumors

The progesterone receptor (PR) mediates the actions of progesterone in the normal and malignant breast. PR is expressed as two proteins, PR B and PR A, which are expressed in normal progesterone target tissues and in breast cancers. A significant proportion of breast cancers contain, in addition, a smaller PR protein of molecular mass 78 kDa (PR78 kDa). The significance of PR78 kDa expression is unknown, and in particular, there are no data on whether PR78 kDa is able to bind ligand and therefore potentially exhibit transcriptional activity. If this smaller PR species exhibits similar differences in function as have been evidenced in vitro for PR A relative to PR B, it is possible that this PR species may be an important component in determination of progesterone response in breast cancer. The purpose of this study was to determine whether the PR78 kDa protein in breast tumors is able to bind ligand and to determine whether posttranscriptional mechanisms contribute to its formation in breast cancers. There was no evidence that PR78 kDa was derived from proteolytic activity of either PR B or PR A. Similarly, although exon-deleted PR transcripts were detected (which could, if translated, give rise to a PR protein similar in size to PR78 kDa), neither the abundance of such transcripts nor their relationship to levels of expressed PR78 kDa protein supported a role for exon deletion in formation of this truncated PR protein. PR78 kDa was not recognized by an antibody specific for PR B, indicating that, like PR A, it lacks the N-terminal portion of PR. PR78 kDa was able to bind the progestin ligand, indicating that it may have transcriptional activity. In summary, this study has shown that a truncated PR protein, found in breast cancers, is ligand-binding and seems to be derived from PR A, indicating that it may have a role in progesterone signaling, although a deeper understanding of its role, if any, in breast cancer remains to be established.