Steroid Receptor RNA Activator Protein (SRAP): A Potential New Prognostic Marker for Estrogen Receptor-Positive/Node-Negative/Younger Breast Cancer Patients

Purpose: The steroid receptor RNA activator (SRA) is a functional RNA suspected to participate in the mechanisms underlying breast tumor progression. This RNA is also able to encode for a protein, SRAP, whose exact function remains to be determined. Our aim was to assess, in a large breast cancer cohort, whether levels of this protein could be associated with outcome or established clinical parameters.Experimental Design: Following antibody validation, we have assessed SRAP expression by tissue-microarray (TMA) analysis of 372 tumors with known steroid receptor and node status. Clinical follow-up was available for all the corresponding patients. Immunohistochemical scores were independently determined by two investigators and averaged. Statistical analyses were performed using standard univariate and multivariate tests.Results: SRAP levels were significantly (Mann-Whitney rank sum test, P<0.05) higher in estrogen receptor-alpha positive (ER+, n = 273), in progesterone receptor positive (PR+, n= 256) and in older patients (age ≥ 65 years, n = 183). When considering ER+ tumors, PR+ tumors, or young patients (< 65 years), patients with high SRAP expression had a significantly (Mantel-Cox test, P < 0.05) worse breast cancer specific survival (BCSS) than patients with low SRAP levels. SRAP also appeared as a very powerful indicator of poor prognostic for BCSS in the subset of ER+, node negative and young breast cancer patients (Cox regression analysis, n = 60, BCSS Hazard Ratio=13.937, P<0.0001).Conclusion: Our data suggest that SRAP might be a new predictor of breast cancer specific survival in younger breast cancer patients with ER+/node negative tumors.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2017.

miRNA Profiling of Endocrine-Resistant Breast Tumours

RationalemiRNAs are a relatively recently discovered class of molecules with major implications in cellular biology, including tumorigenesis; yet little is known about their possible involvement in the development of endocrine resistance in breast cancer. The aim of this study was to identify sub-groups of endocrine-resistant tumours with distinctive miRNA profiles.Methods and ResultsFrozen biopsies were obtained from a series of 51 breast cancers, which were either progressing primary tumours, local recurrences or contra-lateral breast lesions developed while patients received endocrine treatment. Hormonal treatment included aromatase inhibitors or tamoxifen, most of the patients reached post-menopausal age, miRNA profiles were obtained using Illumina DASL® Sentrix Array Matrix.Un-supervised hierarchical clustering split 51 studied endocrine resistant tumours into two major groups, distinctive in their miRNA profiles. Several of miRNAs discriminating between the clusters have already been implemented in breast cancer (mir7, mir10a, mir205, mir206, mir 210). Most of the other miRNAs associated with the main tumour clusters are yet to be studied in relation to breast cancer biology (e.g. mir192, mir625, mir941, mir145 and mir512 among others). The miRNA-based tumour clusters were not clearly associated with a specific treatment or type of resistance. The miRNAs most clearly able to discriminate between tumours resistant to AIs and Tamoxifen included mir186, mir196a, mir196b and miR-594:9.1 (p<0.05, fold change >1.2).DiscussionThe results show heterogeneity of miRNA profiles in endocrine resistant breast cancers, for the first time suggesting that endocrine resistant tumours can be split into two major molecular sub-groups basing on their miRNA profiles. The results suggest that (i) miRNA-mediated gene expression regulation may be involved in the mechanisms of endocrine resistance and (ii) miRNA profiling allows different molecular sub-classes of endocrine-resistant tumours to be distinguished.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5130.

Gene Expression Profiles of Endocrine Resistant Breast Tumours

AimTo identify molecular sub-classes of endocrine-resistant breast tumours.MethodsWhole genome expression profiles of 55 endocrine-resistant tumours were obtained using Illumina HT-12 BeadChip arrays. Endocrine resistance was defined as either (i) tumour increased in size during hormonal treatment or (ii) appearance of local recurrence or (iii) contra-lateral breast lesion (metastases or new cancers) during hormonal treatment. Most of the treated patients were post-menopausal. Hormonal treatment included either aromatase inhibitors (letrozole, anastrazole, arimidex) or tamoxifen.ResultsUnsupervised hierarchical clustering using 500 most variable genes split tumours into three major clusters of approximately equal size. The genes discriminating between these clusters included oestrogen receptor- and proliferation- associated set of genes (ESR1, TFF1, TFF3, FOXA1, AGR2, AGR3, XBP1, GATA3, PRAD6B, MYB, CCND1), and stroma-related genes (DCN, COL1A1, COL1A2, COL3A1, COL5A2). Initial analysis of the studied tumours was unable to identify genes associated with clinical features. Sub-division of the dataset may be required to identify these genes more clearly. Genes that tended to separate between tumours resistant to AI and Tamoxifen included MYB, GPR137B, RNF19A, FRMD6, ZNF217 and RPS12. More detailed analysis of the data is underway.DiscussionUnderstanding and overcoming of endocrine resistance will improve treatment results for the majority of breast cancer patients. This abstract reports a new gene expression dataset to compare molecular features of biopsies collected from tumours growing while on endocrine treatment. The initial analysis demonstrates diversity of the resistance mechanisms, enhancing development of individual approaches to endocrine-resistant tumours.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5132.

Genetic variation in resistance to mixed, predominantly Teladorsagia circumcincta nematode infections of sheep: from heritabilities to gene identification

In cool temperate areas, such as Scotland, sheep are infected by a variety of nematodes but the dominant nematode is Teladorsagia circumcincta. Resistant animals have one or more of the following features: fewer adult nematodes, more inhibited larvae, shorter adult nematodes and decreased production of nematode eggs. In lambs at the end of the first grazing season, the heritability of adult worm length is very strong, whereas the heritability of egg production is moderate. The heritability of worm number is low while there is no detectable genetic variation in the number of inhibited larvae. The major mechanisms underlying resistance to T. circumcincta appear to be the IgA mediated suppression of worm growth and the mast cell mediated regulation of worm number. Mast cell responses are slow to develop, possibly because they are responsible for protein loss and reduced growth of the host. Two genes have been repeatedly associated with resistance to T. Circumcincta: the MHC class II DRB1 locus on chromosome 20 and the interferon-gamma locus on chromosome 3. Although the causative mutations are still unknown both genes are plausible candidates.

Detection of genes with moderate effects on disease resistance using ovine mhc and resistance to nematodes as an example

Detecting some of the genes that influence disease resistance would improve our understanding of the processes that cause disease and also simplify disease control. Genes within the major histocompatibility complex (mhc) are strong candidates for disease resistance and they have been intensely studied for the last 30 years. Recently, several groups working independently have reported the existence of alleles within the mhc that are associated with enhanced resistance to nematode infection. This article uses hindsight to describe some of the potential pitfalls that hinder the search for valid disease resistance genes. The search requires a good understanding of disease biology, molecular genetics, statistical genetics and especially, the design and analysis of experiments. The power to detect mhc effects is quite low and is quite sensitive to the frequency of the putative resistance alleles.

Endothelial cell response to biomechanical forces under simulated vascular loading conditions

In vivo, endothelial cells (EC) are constantly exposed to the haemodynamic forces (HF) of pressure, wall shear stress and hoop stress. The main aim of this study was to design, create and validate a novel perfusion bioreactor capable of delivering shear stress and intravascular pressure to EC in vitro and to characterise their morphology, orientation and gene expression. Here we report the creation and validation of such a simulator and the dual application of pressure (120/60 mmHg) and low shear stress (5 dyn/cm(2)) to a monolayer of EC established on a non-compliant silicone tube. Under these conditions, EC elongated and realigned obliquely to the direction of applied shear stress in a time-dependent manner. Furthermore, randomly distributed F-actin microfilaments reorganised into long, dense stress fibres crossing the cells in a direction perpendicular to that of flow. Finally, combinatorial biomechanical conditioning of EC induced the expression of the inflammatory-associated E-selectin gene.

Proteomic analysis to dissect mitoxantrone resistance-associated proteins in a squamous lung carcinoma

BACKGROUND

Mitoxantrone resistance has been related to the expression of a drug efflux pump breast cancer resistance pump (BCRP) but little is known of the intracellular protein changes. In this work, differential protein expression in a squamous lung carcinoma cell line, DLKP, and its mitoxantrone-resistant variant (DLKP-Mitox) was investigated to elucidate other changes associated with mitoxantrone resistance.

MATERIALS AND METHODS

Differential protein expression between DLKP and DLKP-Mitox was investigated using 2D-DIGE technology. Proteins of interest were identified by MALDI-ToF mass spectrometry. Western blotting was used to confirm and validate some of these changes.

RESULTS

Biological variation analysis in Decyder software revealed a total of 343 proteins to be differentially regulated with p < 0.05. Identification of 61 proteins of interest by mass spectrometry revealed changes in proteins involved in many cellular processes including apoptosis and differentiation.

CONCLUSION

Alterations in these cellular processes and proteins present alternative sites to circumvent resistance to mitoxantrone.

A hotel-based outbreak of Salmonella enterica subsp. Enterica serovar Enteritidis (Salmonella Enteritidis) in the United Kingdom, 2006

An outbreak of food-borne Salmonella Enteritidis PT4 occurred in Cumbria, in north-west England, in the summer of 2006. Fifteen people, all with positive stool samples, met the case definition; three of these were admitted to hospital, including one patient who died. Preliminary investigations suggested a link to a meal served at a local hotel. A case control study was implemented, together with microbiological and environmental investigations. Fifteen microbiologically confirmed cases and 27 unmatched controls were included in the study, controls being randomly selected from people who had eaten at the hotel on the same day. The epidemiological evidence indicated a very strong association between infection and consumption of tiramisu made with raw shell eggs, although none were available for microbiological investigation. These results are in line with other salmonellosis outbreaks that have been associated with the use of raw shell eggs in food manufacturing and production. This paper highlights the continuing need for a greater awareness by those who work in the food industry of the health risks associated with the consumption of raw shell eggs.

A hotel-based outbreak of Salmonella enterica subsp. Enterica serovar Enteritidis (Salmonella Enteritidis) in the United Kingdom, 2006

An outbreak of food-borne Salmonella Enteritidis PT4 occurred in Cumbria, in north-west England, in the summer of 2006. Fifteen people, all with positive stool samples, met the case definition; three of these were admitted to hospital, including one patient who died. Preliminary investigations suggested a link to a meal served at a local hotel. A case control study was implemented, together with microbiological and environmental investigations. Fifteen microbiologically confirmed cases and 27 unmatched controls were included in the study, controls being randomly selected from people who had eaten at the hotel on the same day. The epidemiological evidence indicated a very strong association between infection and consumption of tiramisu made with raw shell eggs, although none were available for microbiological investigation. These results are in line with other salmonellosis outbreaks that have been associated with the use of raw shell eggs in food manufacturing and production.This paper highlights the continuing need for a greater awareness by those who work in the food industry of the health risks associated with the consumption of raw shell eggs.

Establishing a master's degree programme in bioinformatics: challenges and opportunities

The development of the Bioinformatics MS degree program at the University of Illinois, the challenges and opportunities associated with such a process, and the current structure of the program is described. This program has departed from earlier University practice in significant ways. Despite the existence of several interdisciplinary programs at the University, a few of which grant degrees, this is the first interdisciplinary program that grants degrees and formally recognises departmental specialisation areas. The program, which is not owned by any particular department but by the Graduate College itself, is operated in a franchise-like fashion via several departmental concentrations. With four different colleges and many more departments involved in establishing and operating the program, the logistics of the operation are of considerable complexity but result in significant interactions across the entire campus.

Efficacy of repeated high-dose hepatitis B vaccine (80 microg) in patients with chronic liver disease

Patients with chronic liver disease (CLD) respond poorly to standard hepatitis B (HBV) vaccine given as sequential 20 microg IM shots because of an overall impaired immune response. Many of these patients go on to liver transplantation and are at risk of acquiring recurrent or de novo HBV infection. To evaluate the efficacy and safety of high-dose (80 microg) IM HBV vaccination in patients with CLD who had previously failed to respond to a standard three-dose schedule of 40 microg IM vaccine given monthly. A retrospective review was undertaken at our institution of 79 patients with CLD who were treated with high-dose (80 microg) HBV vaccinations. All had previously failed a three-dose course of 40 microg HBV vaccine. An HBV vaccine response was defined as an anti-HBs titer greater than 100 mIU/ml. Liver enzymes, creatinine, age, prothrombin time, total vaccine dose, and MELD score were recorded. No adverse events were reported. Seventy-two per cent (57/79) of the subjects had an adequate response after receiving a mean total dose of 220 mug vaccine (range 80-800 microg). Twenty-eight per cent (22/79) of the subjects did not respond after receiving a mean total dose of 420 microg vaccine (range 240-720 microg). Non-responders had more severe hepatic disease defined as a higher mean total bilirubin level (p = 0.003) and a lower mean albumin level (p < 0.05). Age, prothrombin time, MELD score, and creatinine were not statistically significant between the responders and non-responders. Repeated high-dose (80 microg) HBV vaccination, in patients who do not respond to standard HBV vaccine doses, is safe and effective in the majority of patients with CLD.

Atrial fibrillation and thrombosis: immunohistochemical differences between in situ and embolized thrombi

BACKGROUND/OBJECTIVE

Thromboembolism secondary to atrial fibrillation accounts for approximately one-fourth of all strokes. Although considerable resources have been targeted to pharmacologic prophylaxis, neither the cellular nor the biochemical composition of atrial thrombi is known. Quantitative immunohistochemistry was undertaken to define the composition of atrial thrombi and to explore morphological differences between atrial appendage thrombi and those that embolize.

PATIENTS/METHODS

Serial sections of thrombi obtained during valve replacement surgery or embolectomy from 22 patients with atrial fibrillation were stained with antibodies against fibrin, integrin beta3, or tissue factor and analyzed with NIH-image.

RESULTS

Thrombi showed distinct regions staining for either fibrin or platelets and on average, the fibrin-rich regions predominated (P < 0.0001). The platelet content of embolized thrombi was nearly twice that of atrial thrombi (P = 0.02). Non-staining amorphous material comprised nearly half of atrial thrombi in situ, but was rare in embolized thrombi (P < 0.001). Tissue factor colocalized to areas rich in platelets and granulocytes.

CONCLUSIONS

The abundance of fibrin relative to platelets underscores the enhanced efficacy of warfarin prophylaxis in clinical trials. The finding of tissue factor localized to platelet-leukocyte clusters suggests its blood-borne origin. Compositional differences between in situ and embolized thrombi suggest directions for investigating propensity for embolization.