| 1. |
- McSherry, Elaine A., et al.
(författare)
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JAM-A expression positively correlates with poor prognosis in breast cancer patients
- 2009
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 125:6, s. 1343-1351
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Tidskriftsartikel (refereegranskat)abstract
- The cell-cell adhesion protein junctional adhesion molecule-A (JAM-A) influences; epithelial cell morphology and migration. As migration is required for tumor cell invasion and metastasis, we sought to elucidate the role of JAM-A in invasive breast cancer. A breast cancer tissue microarray was analyzed for JAM-A protein expression, in parallel with analysis of JAM-A gene expression data from a breast cancer clinical dataset. Our data demonstrate a novel association between JAM-A gene and protein upregulation and poor prognosis in breast cancer. To mechanistically dissect this process, we used lentiviral technology to stably knock down JAM-A gene expression by shRNA in MCF7 breast cancer cells, which express high-endogenous levels of JAM-A. We also antagonized JAM-A function in wild-type MCF7 cells using an inhibitory antibody that blocks JAM-A dimerization. Knockdown or functional antagonism of JAM-A decreased breast cancer cell migration in scratch-wound assays. Reductions in beta 1-integrin protein levels were observed after JAM-A-knockdown in MCF7 cells, suggesting a mechanism for reduced motility after loss of JAM-A. Consistent with this hypothesis, tissue microarray analysis of beta 1-integrin protein expression in invasive breast cancer tissues revealed a trend toward high beta 1-integrin protein levels being indicative of poor prognosis. Twenty-two percent of patients were observed to coexpress high levels of JAM-A and beta 1-integrin protein, and MDA-MB-231 breast cells stably overexpressing JAM-A showed an increase in beta 1-integrin protein expression. Our results are consistent with a previously unreported role for JAM-A overexpression as a possible mechanism contributing to progression in primary breast cancer; and a potential therapeutic target. (C) 2009 UICC
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| 2. |
- Brennan, Donal J., et al.
(författare)
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CA IX is an independent prognostic marker in premenopausal breast cancer patients with one to three positive lymph nodes and a putative marker of radiation resistance
- 2006
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Ingår i: Clinical Cancer Research. - 1078-0432. ; 12:21, s. 6421-6431
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Hypoxia in breast cancer is associated with poor prognosis and down-regulation of the estrogen receptor. Carbonic anhydrase IX (CA IX) is a hypoxia-inducible gene that has been associated with poor outcome in many epithelial cancers. Previous studies of CA IX in breast cancer have been carried out on mixed cohorts of premenopausal and postmenopausal patients with locally advanced disease and varying treatment regimens. We examined the potential prognostic and predictive role of CA IX in premenopausal breast cancer patients. Experimental Design: Using tissue microarrays, we analyzed CA IX expression in 400 stage 11 breast cancers from premenopausal women. The patients had previously participated in a randomized control trial comparing 2 years of tamoxifen to no systemic adjuvant treatment. Median follow-up was 13.9 years. Results: CA IX expression correlated positively with tumor size, grade, hypoxia-inducible factor 1 alpha Ki-67, cyclin E, and cyclin A2 expression. CA IX expression correlated negatively with cyclin D1, estrogen receptor, and progesterone receptor. CA IX expression was associated with a reduced relapse-free survival (P = 0.032), overall survival (P = 0.022), and breast cancer specific survival (P = 0.005). Multivariate analysis revealed that CA IX was an independent prognostic marker in untreated patients with one to three positive lymph nodes (hazard ratio, 3.2; 95% confidence interval, 1.15-9.13; P = 0.027). Conclusion: CA IX is marker of poor prognosis in premenopausal breast cancer patients and it is an independent predictor of survival in patients with one to three positive lymph nodes. As all these patients received locoregional radiation therapy, CA IX may be associated with resistance to radiotherapy.
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| 3. |
- Brennan, Donal, et al.
(författare)
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The transcription factor Sox11 is a prognostic factor for improved recurrence-free survival in epithelial ovarian cancer
- 2009
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Ingår i: European Journal of Cancer. - : Elsevier BV. - 1879-0852 .- 0959-8049. ; 45:8, s. 1510-1517
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Background: Current prognostic molecular markers for epithelial ovarian cancer (EOC) are insufficient. The aim of the current study was to investigate the role of Sox11 in EOC Methods: Using an in silico transcriptomic screen Sox11 was identified as a potential EOC biomarker. Sox11 protein expression was evaluated using immunohistochemistry (IHC) in 76 EOC cases, which were analyzed using automated algorithms to develop a quantitative scoring model. Results: Sox11 mRNA expression was up-regulated in EOC compared to normal tissues. Automated analysis of Sox11 in the EOC cohort revealed high expression of Sox11, in 40% of tumours, who had an improved recurrence free survival (RFS) (p= 0.002). Multivariate analysis confirmed Sox11 was an independent predictor of improved RFS after controlling for stage and grade. Conclusions: These data suggest that Sox11 is a new prognostic marker in EOC. Loss of SOX 11 is associated with a decreased RFS and a more aggressive phenotype.
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| 4. |
- Gallagher, William M., et al.
(författare)
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Molecular basis of cell-biomaterial interaction: Insights gained from transcriptomic and proteomic studies
- 2006
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Ingår i: Biomaterials. - : Elsevier BV. - 1878-5905 .- 0142-9612. ; 27:35, s. 5871-5882
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Forskningsöversikt (refereegranskat)abstract
- With the growing interest in clinical interventions that involve medical devices, the role for new biomaterials in modern medicine is currently expanding at a phenomenal rate. Failure of most implant materials stems from an inability to predict and control biological phenomena, such as protein adsorption and cell interaction, resulting in an inappropriate host response to the materials. Contemporary advances in biological investigation are starting to shift focus in the biomaterials field, in particular with the advent of high-throughput methodologies for gene and protein expression profiling. Here, we examine the role that emerging transcriptomic and proteomic technologies could play in relation to biomaterial development and usage. Moreover, a number of studies are highlighted which have utilized such approaches in order to try to create a deeper understanding of cell-biomaterial interactions and, hence, improve our ability to predict and control the biocompatibility of new materials. (c) 2006 Elsevier Ltd. All rights reserved.
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| 5. |
- Lanigan, Fiona, et al.
(författare)
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Increased claudin-4 expression is associated with poor prognosis and high tumour grade in breast cancer
- 2009
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 124:9, s. 2088-2097
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Tidskriftsartikel (refereegranskat)abstract
- The role of intercellular tight junctions in breast epithelia[ cells is traditionaliy thought to be in maintaining polarity and barrier function. However, claudin-4, a tight junction protein, is overexpressed in breast tumour cells compared to normal epithelial cells, which generally corresponds to a loss in polarity. The aim of this study was to investigate the distribution and potential clinical value of claudin-4 in breast cancer, and to evaluate its usefulness as a prognostic and predictive biomarker. Expression of claudin-4 was initially examined by Western blot analysis in a cohort of 88 breast tumours, and was found to correlate positively with tumour grade and negatively with ER. Claudin-4 expression was then evaluated by immunohistochemistry in a larger cohort of 299 tumours represented on a tissue microarray. Claudin-4 expression correlated positively with tumour grade and Hcr2, and negatively with ER. High claudin-4 expression was also associated with worse breast cancer-specific survival (p = 0.0031), recurrence-free survival (P = 0.025) and overall survival (p = 0.034). Multivariate analysis revealed that claudin-4 independently predicted survival in the entire cohort (HR 1.95; 95%CI 1.01-3.79; p = 0.047) and in the ER positive subgroup treated with adjuvant tamoxifen (FIR 4.34; 95%C1 1.14-16.53; p = 0.032). This relationship between increased claudin-4 expression and adverse outcome was validated at the mRNA level in a DNA microarray dataset of 295 breast tumours. We conclude that high levels of claudin-4 protein are associated with adverse outcome in breast cancer patients, including the subgroup of patients treated with adjuvant tamoxifen. (C) 2008 Wiley-Liss, Inc.
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| 6. |
- Lynch, Iseult, et al.
(författare)
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Novel method to prepare morphologically rich polymeric surfaces for biomedical applications via phase separation and arrest of microgel particles
- 2006
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Ingår i: The Journal of Physical Chemistry Part B. - : American Chemical Society (ACS). - 1520-5207 .- 1520-6106. ; 110:30, s. 14581-14589
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Tidskriftsartikel (refereegranskat)abstract
- We outline here a simple method to prepare polymeric surfaces of controlled surface topography on the micrometer scale, via assembly and arrest of microgel particles, for use in a range of biological applications to modify cell adhesion and spreading. In previous work by other groups, it has transpired that topography on the nanoscale is unlikely to be useful for this purpose, as roughness on this scale is often covered or coated by serum derived proteins during the early stages of cell adhesion and cells can easily bridge nanoscale roughness. Therefore, in our work, we have focused on roughness or topographic variations on the micrometer length scale. The basic idea is to modify the interactions between particles, thereby causing the microgel particles to phase separate into particle-dense and particle-dilute domains and to arrest these domains on the surface. The result is the creation of surfaces with controlled topography. By changing the particle size, it is possible to alter the size of the pores formed and their distribution in the film. Preliminary results show that the system can readily be arrested into a homologous series of such structures (formed from microgel particles of the same size and same chemical structure) with biological implications. At the extremes of this series, large phenotypic differences are observed between cells, ranging (at one end) from localization of the cells in the pores to (at the other end) cells that avoid such localization, and remain extended, growing along the ridges between the pores. This constitutes a sort of cell localization transition on a surface with identical chemical components, where only the morphology has been adjusted.
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| 7. |
- O'Brien, Sallyarm L., et al.
(författare)
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CENP-F expression is associated with poor prognosis and chromosomal instability in patients with primary breast cancer
- 2007
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136. ; 120:7, s. 1434-1443
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Tidskriftsartikel (refereegranskat)abstract
- DNA microarrays have the potential to classify tumors according to their transcriptome. Tissue microarrays (TMAs) facilitate the validation of biomarkers by offering a high-throughput approach to sample analysis. We reanalyzed a high profile breast cancer DNA microarray dataset containing 96 tumor samples using a powerful statistical approach, between group analyses. Among the genes we identified was centromere protein-F (CENP-F), a gene associated with poor prognosis. In a published follow-up breast cancer DNA microarray study, comprising 295 tumour samples, we found that CENP-F upregulation was significantly associated with worse overall survival (p < 0.001) and reduced metastasis-free survival (p < 0.001). To validate and expand upon these findings, we used 2 independent breast cancer patient cohorts represented on TMAs. CENP-F protein expression was evaluated by immunohistochemistry in 91 primary breast cancer samples from cohort I and 289 samples from cohort II. CENP-F correlated with markers of aggressive tumor behavior including ER negativity and high tumor grade. In cohort I, CENP-F was significantly associated with markers of CIN including cyclin E, increased telomerase activity, c-Myc amplification and aneuploidy. In cohort II CENP-F correlated with VEGFR2, phosphorylated Ets-2 and Ki67, and in multivariate analysis, was an independent predictor of worse breast cancer-specific survival (p = 0.036) and overall survival (p = 0.040). In conclusion, we identified CENP-F as a biomarker associated with poor outcome in breast cancer and showed several novel associations of biological significance. (c) 2007 Wiley-Liss, Inc.
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| 8. |
- Rexhepaj, Elton, et al.
(författare)
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Novel image analysis approach for quantifying expression of nuclear proteins assessed by immunohistochemistry: application to measurement of oestrogen and progesterone receptor levels in breast cancer
- 2008
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Ingår i: Breast Cancer Research. - : Springer Science and Business Media LLC. - 1465-5411 .- 1465-542X. ; 10:5
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Tidskriftsartikel (refereegranskat)abstract
- Introduction Manual interpretation of immunohistochemistry (IHC) is a subjective, time-consuming and variable process, with an inherent intra-observer and inter-observer variability. Automated image analysis approaches offer the possibility of developing rapid, uniform indicators of IHC staining. In the present article we describe the development of a novel approach for automatically quantifying oestrogen receptor (ER) and progesterone receptor (PR) protein expression assessed by IHC in primary breast cancer. Methods Two cohorts of breast cancer patients (n = 743) were used in the study. Digital images of breast cancer tissue microarrays were captured using the Aperio ScanScope XT slide scanner (Aperio Technologies, Vista, CA, USA). Image analysis algorithms were developed using MatLab 7 (MathWorks, Apple Hill Drive, MA, USA). A fully automated nuclear algorithm was developed to discriminate tumour from normal tissue and to quantify ER and PR expression in both cohorts. Random forest clustering was employed to identify optimum thresholds for survival analysis. Results The accuracy of the nuclear algorithm was initially confirmed by a histopathologist, who validated the output in 18 representative images. In these 18 samples, an excellent correlation was evident between the results obtained by manual and automated analysis (Spearman's rho = 0.9, P < 0.001). Optimum thresholds for survival analysis were identified using random forest clustering. This revealed 7% positive tumour cells as the optimum threshold for the ER and 5% positive tumour cells for the PR. Moreover, a 7% cutoff level for the ER predicted a better response to tamoxifen than the currently used 10% threshold. Finally, linear regression was employed to demonstrate a more homogeneous pattern of expression for the ER (R = 0.860) than for the PR (R = 0.681). Conclusions In summary, we present data on the automated quantification of the ER and the PR in 743 primary breast tumours using a novel unsupervised image analysis algorithm. This novel approach provides a useful tool for the quantification of biomarkers on tissue specimens, as well as for objective identification of appropriate cutoff thresholds for biomarker positivity. It also offers the potential to identify proteins with a homogeneous pattern of expression.
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| 9. |
- Stromberg, Sara, et al.
(författare)
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Selective Expression of Syntaxin-7 Protein in Benign Melanocytes and Malignant Melanoma
- 2009
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 8:4, s. 1639-1646
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Tidskriftsartikel (refereegranskat)abstract
- To search for proteins expressed in human melanocytes and melanoma, we employed an antibody-based proteomics strategy to screen for protein expression in tissue microarrays containing normal tissues, cancer tissues and cell lines. Syntaxin-7 (STX7) was identified as a novel protein, not previously characterized in cells of melanocytic lineage, displaying a cell type-specific protein expression pattern. In tumor tissues, STX7 was expressed in malignant melanoma and lymphoma. The protein was further characterized regarding subcellular localization, specificity, tissue distribution pattern and potential as a diagnostic and prognostic marker using cell lines and tissue microarrays containing normal skin, melanocytic nevi and primary and metastatic melanoma. STX7 was expressed in normal melanocytes, various benign melanocytic nevi, atypical nevi and malignant melanoma. Analysis in two independent melanoma cohorts demonstrated STX7 expression in nearly all investigated tumors, although at varying levels (>90% positive tumors). The expression level of STX7 protein was inversely correlated to tumor stage, suggesting that decreased expression of STX7 is associated with more aggressive tumors. In conclusion, we present protein profiling data for a novel protein showing high sensitivity and specificity for cells of the melanocytic lineage. The presented antibody-based proteomics approach can be used as an effective strategy to identify novel tumor markers and evaluate their potential clinical relevance.
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| 10. |
- Sutton, Mark A., et al.
(författare)
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Dynamics of ammonia exchange with cut grassland : Synthesis of results and conclusions of the GRAMINAE Integrated Experiment
- 2009
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Ingår i: Biogeosciences. - Goettingen : Nicolaus Copernicus University Press. - 1726-4170 .- 1726-4189. ; 6:12, s. 2907-2934
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Tidskriftsartikel (refereegranskat)abstract
- Improved data on biosphere-atmosphere exchange are fundamental to understanding the production and fate of ammonia (NH3) in the atmosphere. The GRAMINAE Integrated Experiment combined novel measurement and modelling approaches to provide the most comprehensive analysis of the interactions to date. Major intercomparisons of micrometeorological parameters and NH3 flux measurements using the aerodynamic gradient method and relaxed eddy accumulation (REA) were conducted. These showed close agreement, though the REA systems proved insufficiently precise to investigate vertical flux divergence. Grassland management had a large effect on fluxes: emissions increased after grass cutting (−50 to 700 ng m-2 s-1 NH3) and after N-fertilization (0 to 3800 ng m-2 s -1) compared with before the cut (−60 to 40 ng m-2 s -1). © Author(s) 2009.
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