Molecular basis for estrogen receptor alpha deficiency in BRCA1-linked breast cancer

Background BRCA1-mutant breast tumors are typically estrogen receptor alpha (ER alpha) negative, whereas most sporadic tumors express wild-type BRCA1 and are ER alpha positive. We examined a possible mechanism for the observed ER alpha-negative phenotype of BRCA1-mutant tumors.

Methods We used a breast cancer disease-specific microarray to identify transcripts that were differentially expressed between paraffin-embedded samples of 17 BRCA1-mutant and 14 sporadic breast tumors. We measured the mRNA levels of estrogen receptor 1 (ESR1) ( the gene encoding ER alpha), which was differentially expressed in the tumor samples, by quantitative polymerase chain reaction. Regulation of ESR1 mRNA and ER alpha protein expression was assessed in human breast cancer HCC1937 cells that were stably reconstituted with wild-type BRCA1 expression construct and in human breast cancer T47D and MCF-7 cells transiently transfected with BRCA1-specific short-interfering RNA ( siRNA). Chromatin immunoprecipitation assays were performed to determine if BRCA1 binds the ESR1 promoter and to identify other interacting proteins. Sensitivity to the antiestrogen drug fulvestrant was examined in T47D and MCF-7 cells transfected with BRCA1-specific siRNA. All statistical tests were two-sided.

Results Mean ESR1 gene expression was 5.4-fold lower in BRCA1-mutant tumors than in sporadic tumors ( 95% confidence interval [CI]=2.6-fold to 40.1-fold, P =.0019). The transcription factor Oct-1 recruited BRCA1 to the ESR1 promoter, and both BRCA1 and Oct-1 were required for ER alpha expression. BRCA1-depleted breast cancer cells expressing exogenous ER alpha were more sensitive to fulvestrant than BRCA1-depleted cells transfected with empty vector ( T47D cells, the mean concentration of fulvestrant that inhibited the growth of 40% of the cells [IC40] for empty vector versus ER alpha: > 10(-5) versus 8.0 x 10(-9) M [ 95% CI=3.1x10(-10) to 3.2 x 10(-6) M]; MCF-7 cells, mean IC40 for empty vector versus ER alpha : > 10(-5) versus 4.9 x 10(-8) M [ 95% CI=2.0 x 10(-9) to 3.9 x 10(-6) M]).

Conclusions BRCA1 alters the response of breast cancer cells to antiestrogen therapy by directly modulating ER alpha expression.

BRCA1 mRNA Expression Levels Predict for Overall Survival in Ovarian Cancer after Chemotherapy.

We investigated whether BRCA1 mRNA expression levels may represent a biomarker of survival in sporadic epithelial ovarian cancer following chemotherapy treatment. EXPERIMENTAL DESIGN: The effect of loss of BRCA1 expression on chemotherapy response in ovarian cancer was measured in vitro using dose inhibition assays and Annexin V flow cytometry. Univariate and multivariate analyses were done to evaluate the relationship between BRCA1 mRNA expression levels and survival after chemotherapy treatment in 70 fresh frozen ovarian tumors. RESULTS: We show that inhibition of endogenous BRCA1 expression in ovarian cancer cell lines results in increased sensitivity to platinum therapy and decreased sensitivity to antimicrotubule agents. In addition, we show that patients with low/intermediate levels of BRCA1 mRNA have a significantly improved overall survival following treatment with platinum-based chemotherapy in comparison with patients with high levels of BRCA1 mRNA (57.2 versus 18.2 months; P = 0.0017; hazard ratio, 2.9). Furthermore, overall median survival for higher-BRCA1-expressing patients was found to increase following taxane-containing chemotherapy (23.0 versus 18.2 months; P = 0.12; hazard ratio, 0.53). CONCLUSIONS: We provide evidence to support a role for BRCA1 mRNA expression as a predictive marker of survival in sporadic epithelial ovarian cancer.

A comparison of a range of models for dispersion in a partially stratified room

A comparative study of models used to predict contaminant dispersion in a partially stratified room is presented. The experiments were carried out in a ventilated test room, with an initially evenly dispersed pollutant. Air was extracted from the outlet in the ceiling of the room at 1 and 3 air changes per hour. A small temperature difference between the top and bottom of the room causes very low air velocities, and higher concentrations, in the lower half of the room. Grid-independent CFD calculations were compared with predictions from a zonal model and from CFD using a very coarse grid. All the calculations show broadly similar contaminant concentration decay rates for the three locations monitored in the experiments, with the zonal model performing surprisingly well. For the lower air change rate, the models predict a less well mixed contaminant distribution than the experimental measurements suggest. With run times of less than a few minutes, the zonal model is around two orders of magnitude faster than coarse-grid CFD and could therefore be used more easily in parametric studies and sensitivity analyses. For a more detailed picture of internal dispersion, a CFD study using coarse and standard grids may be more appropriate.

The musculature and associated innervation of adult and intramolluscan stages of Echinostoma caproni (Trematoda) visualised by confocal microscopy

Gross anatomy of muscle and sensory/motor innervation of adult and intramolluscan developmental stages of Echinostoma caproni have been investigated to ascertain the organisation and the functional correlates of any stage-specific patterns of staining. Using indirect immunocytochemistry to demonstrate neuroactive substances and the phalloidin-fluorescence technique for staining myofibril F-actin, the muscle systems and aminergic and peptidergic innervation of daughter rediae, cercariae, metacercariae, and pre- and post-ovigerous adults were examined and compared using confocal scanning laser microscopy. A complex arrangement of specific muscle fibre systems occurs within the body wall (composed of circular, longitudinal and diagonal fibres), suckers (radial, equatorial, meridional), pharynx (radial, circular), gut caeca (mainly circular), cercarial tail (circular, pseudo-striated longitudinal), and ducts of the reproductive system (circular, longitudinal), presumed to serve locomotor, adhesive, alimentary and reproductive functions. Immunostaining for serotonin (5-HT) and FMRFamide-related peptides (FaRPs) was evident throughout the central (CNS) and peripheral (PNS) nervous systems of all stages, and use of dual-labelling techniques demonstrated separate neuronal pathways for 5-HT and FaRP in both CNS and PNS. FaRP expression in the innervation of the ootype wall was demonstrated only in post-ovigerous worms and not in pre-ovigerous worms, suggesting an involvement of FaRP neuropeptides in the process of egg assembly. Comparison of the present findings with those recorded for other digeneans suggests that muscle organisation and innervation patterns in trematodes are highly conserved.

Prevalence of childhood abuse in mothers taking part in a study of parenting their own children.

This paper describes the incidence of maltreatment histories in a community sample of mothers of one-year old infants in Northern Ireland. The occurrence of five subsets of childhood maltreatment is examined: emotional abuse, emotional neglect, physical abuse, physical neglect and sexual abuse. Of the 201 women who completed the Childhood Trauma Questionnaire (CTQ), 70 mothers (35%) reported experiencing one or more types of maltreatment during childhood. Forty-eight mothers (24%) gave a history of being emotionally abused, 43 (21%) of emotional neglect, 27 (13%) of physical abuse, 20 (10%) of sexual abuse, and 19 (10%) of physical neglect. Physical abuse was the only type of maltreatment which showed an association with maternal socio-economic status, with higher incidence reported amongst Occupational Classes 4 and 5 (lower supervisory and technical occupations and semi-routine and routine groups). More than half of those with a history of abuse experienced more than one type of maltreatment (42 mothers or 60% of those reporting maltreatment). Differences in rates of incidence to more recent studies on younger adults are discussed, as well as implications for prevention and intervention.

The Growth, Learning and Development Study: Summary of Research, Findings and Recommendations.

The Growth, Learning and Development (GLAD) study aimed to examine how a broad range of factors influence child weight during the first year of life. Assessments were undertaken within a multidisciplinary team framework. The sample was drawn from the community and data collection was undertaken in the four Greater Belfast Trusts. Twohundred and thirty-four families took part, each receiving a total of five home visits during which physical growth, oral-motor skills and development were assessed. Psychosocial evaluation examined parent-child interaction, feeding and other parental and child characteristics using quantitative and observational techniques. This paper outlines the main findings and recommendations from the GLAD study.

Maternal mental health and non-organic failure to thrive.

This study reports on the first phase of a large-scale, longitudinal, multidisciplinary community study examining the growth, learning and development of young children with a particular focus on failure to thrive without organic cause. However, the group identified in this study may be better described as weight faltering. This paper examines the psychological data collected using the Parenting Stress Index, Rosenberg Self-Esteem and the General Health Questionnaire in relation to child growth. There were no significant differences between the mothers of the weight faltering and control children in terms of parenting stress, maternal depression, maternal perceptions of their parenting competence or maternal self-esteem. Maternal sensitivity to comments about child size, regardless of direction, had a negative impact on mood.