TNK2 preserves epidermal growth factor receptor expression on the cell surface and enhances migration and invasion of human breast cancer cells

Introduction Amplification of the TNK2 gene in primary tumours correlates with poor prognosis. In accordance, TNK2 overexpression was shown to promote invasion of cancer cells - but the mechanism by which TNK2 mediates these effects is unresolved. TNK2 was suggested to regulate Cdc42-driven migration by activation of breast cancer antioestrogen resistance 1 (BCAR1); however, distinct from this effect is evidence for a role of TNK2 in the regulation of epidermal growth factor receptor (EGFR) endocytosis and degradation. In the present study we sought to investigate whether negative targeting of TNK2 by siRNA could be used to inhibit cancer cell invasion, to establish the contribution of its effect on the EGFR and to consequently attempt to resolve the issue of TNK2's mechanism of action. Methods We used siRNA to knockdown expression of TNK2 and its proposed effector BCAR1 in order to analyse the effect of this knockdown on cancer cell behaviour in vitro. We examined morphological changes using phase-contrast microscopy and immunohistochemistry. Functional parameters examined included apoptosis, proliferation, migration and invasion. We also performed flow cytometry analysis to examine EGFR cell surface expression and carried out western blot to examine the total EGFR levels. Results We observed that targeting of TNK2 by siRNA in breast cancer cells resulted in distinct morphological changes characterised by a stellate appearance and an absence of protrusions at membrane edges. These changes were not recapitulated upon siRNA targeting of BCAR1. We thus hypothesised that a component of the effects induced by TNK2 may be independent of BCAR1. Consistent with the idea of an alternative mechanism for TNK2, we observed that TNK2 associates with activated EGFR in breast cancer cells in a TNK2-kinase-independent manner. Furthermore, we demonstrated that TNK2 functions to maintain EGFRs on the cell surface. We could demonstrate that the main functional effect of activating these surface EGFRs in breast cancer cells is stimulation of migration. In accordance, TNK2 silencing by siRNA led to a significant reduction in cell surface EGFR and to a concomitant decrease in the migratory and invasive capacity of breast cancer cells. Conclusion Our data suggest that TNK2 can enhance migration and invasion of breast cancer cells via preservation of EGFR expression, notwithstanding its previously reported signalling via BCAR1, explaining its oncogenic behaviour in vitro and correlation with metastatic human breast cancer in vivo

Creating an Audio Story with Interactive Binaural Rendering in Virtual Reality

The process of listening to an audiobook is usually a rather passive act that does not require an active interaction. If spatial interaction is incorporated into a storytelling scenario, can open. Possibilities of a novel experience which allows an active participation might affect the user-experience. The aim of this paper is to create a portable prototype system based on an embedded hardware platform, allowing listeners to get immersed in an interactive audio storytelling experience enhanced by dynamic binaural audio rendering. For the evaluation of the experience, a short story based on the horror narrative of Stephen King's Strawberry Springs is adapted and designed in virtual environments. A comparison among three different listening experiences, namely, (i) monophonic (traditional audio story), (ii) static binaural rendering (state-of-the-art audio story), and (iii) our prototype, is conducted. We discuss the quality of the experience based on usability testing, physiological data, emotional assessments, and questionnaires for immersion and spatial presence. Results identify a clear trend for an increase in immersion with our prototype compared to traditional audiobooks, showing also an emphasis on story-specific emotions, i.e., terror and fear

Employment status and commute distance of Canadians with disabilities

Disabilities, Impairments, Employment status, Commute distance, 2006 Participation and Activity Limitation Survey, Canada,