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Background The EphB4 receptor tyrosine kinase is overexpressed in many cancers including prostate cancer. The molecular mechanisms by which this ephrin receptor influences cancer progression are complex as there are tumor-promoting ligand-independent mechanisms in place as well as ligand-dependent tumor suppressive pathways. Methods We employed transient knockdown of EPHB4 in prostate cancer cells, coupled with gene microarray analysis, to identify genes that were regulated by EPHB4 and may represent linked tumor-promoting factors. We validated target genes using qRT-PCR and employed functional assays to determine their role in prostate cancer migration and invasion. Results We discovered that over 500 genes were deregulated upon EPHB4 siRNA knockdown, with integrin β8 (ITGB8) being the top hit (29-fold down-regulated compared to negative non-silencing siRNA). Gene ontology analysis found that the process of cell adhesion was highly deregulated and two other integrin genes, ITGA3 and ITGA10, were also differentially expressed. In parallel, we also discovered that over-expression of EPHB4 led to a concomitant increase in ITGB8 expression. In silico analysis of a prostate cancer progression microarray publically available in the Oncomine database showed that both EPHB4 and ITGB8 are highly expressed in prostatic intraepithelial neoplasia, the precursor to prostate cancer. Knockdown of ITGB8 in PC-3 and 22Rv1 prostate cancer cells in vitro resulted in significant reduction of cell migration and invasion. Conclusions These results reveal that EphB4 regulates integrin β8 expression and that integrin β8 plays a hitherto unrecognized role in the motility of prostate cancer cells and thus targeting integrin β8 may be a new treatment strategy for prostate cancer. Electronic supplementary material The online version of this article (doi:10.1186/s12885-015-1164-6) contains supplementary material, which is available to authorized users.

Several Eph receptor tyrosine kinases (RTKs) are commonly over-expressed in epithelial and mesenchymal cancers and are recognized as promising therapeutic targets. Although normal interaction between Eph receptors and their ephrin ligands stimulates kinase activity and is generally tumor suppressive, significant Eph over-expression allows activation of ligand- and/or kinase-independent signaling pathways that promote oncogenesis. Single-agent kinase inhibitors are widely used to target RTK-driven tumors but acquired and de novo resistance to such agents is a major limitation to effective clinical use. Accumulating evidence suggests that Ephs can be inhibited by "leaky" or low-specificity kinase inhibitors targeted at other RTKs. Such off-target effects may therefore inadvertently promote ligand- and/or kinase-independent oncogenic Eph signaling, thereby providing a new mechanism by which resistance to the RTK inhibitors can emerge. We propose that combining specific, non-leaky kinase inhibitors with tumor-suppressive stimulators of Eph signaling may provide more effective treatment options for overcoming treatment-induced resistance and clinical failure.

27th European Photovoltaic Solar Energy Conference and Exhibition; 1329-1334, Recent trends show that screen printing technology still dominates c-Si solar cell metallization with over 90% share. Process simplicity and low cost are the major attributes to this, however screen printing has some shortcomings with respect to fine lines, precision and quality. The purpose of this paper is to develop a practical, cost effective and simple model together with evaluation procedure that can assist in reducing test time, material requirement and complexity. To achieve this, we created a mathematical model to predict screen printability in respect to screen mesh material, meshing parameters and EOM (Emulsion Over Mesh). Finally a new test procedure is introduced to evaluate screen printed metallization. Both the model and the procedure where tested on 2 commercial pastes in combination with several screen design parameters. The model proved practical and user friendly and was verified by testing on 2 different stainless steel (SS) mesh screens and vecry mesh screen (V-screen) each with different EOM. Combining the model with our proposed test procedure showed that Vscreens out performed SS screens for similar screen parameters on both pastes tested.

27th European Photovoltaic Solar Energy Conference and Exhibition; 2039-2043, The Metal Wrap Through (MWT) cell architecture is a prime candidate for the next step in the race for higher solar module efficiency but, like all new technology, it still has to pass the cost-per-watt-peak litmus test. Process flow complexity and cost will be key factors for successful introduction into the market. In this work we look at the isolation process as an opportunity for reducing the cost-per-watt-peak, and experimentally compare laser groove versus wet chemical isolation, two industrially mature isolation technologies, by weighing their potential for cost-effective industrialization in a process flow for Cz silicon MWT cells. We show that each isolation process can produce equally good cells, but that they are faced with different challenges in respect to loss mechanisms, and that process flows based on either isolation technique each have their merits and banes. We believe that the apparent simplicity of wet chemical isolation seems to favor it over laser isolation for MWT process integration, offering the opportunity of a simple upgrade to a standard Al-BSF production line.

27th European Photovoltaic Solar Energy Conference and Exhibition; 1379-1383, In back contact cells of the ‘metal wrap through’ (MWT) architecture, metallized vias are the most important feature introduced compared to standard cells. While the vias are required to bring the contact from the front of the cell to the back, they can contribute significantly to the resistive losses in the cell. Furthermore, since typically several vias are used in parallel, assessing the reliability of the via metallization process on a cell is problematic. In this paper, we describe a methodology that allows detailed characterization of MWT vias through dedicated test structures. Similar structures are known in micro-electronics, but here we discuss the specific advantages and disadvantages of the approach when applied to solar cells. Individual via resistance values of 5-30 mΩ were measured on test wafers at different locations on the cell. The cross section of the vias clearly showed that some of the vias were partially filled or not filled to the top of the wafer due to poor uniformity of the via drilling and/or bad printing process. These lead to the conclusion that for proper via filling, one has to control the printing and drilling processes.