38 research outputs found

    Humanization of the Prostate Microenvironment Reduces Homing of PC3 Prostate Cancer Cells to Human Tissue-Engineered Bone.

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    The primary tumor microenvironment is inherently important in prostate cancer (PCa) initiation, growth and metastasis. However, most current PCa animal models are based on the injection of cancer cells into the blood circulation and bypass the first steps of the metastatic cascade, hence failing to investigate the influence of the primary tumor microenvironment on PCa metastasis. Here, we investigated the spontaneous metastasis of PC3 human PCa cells from humanized prostate tissue, containing cancer-associated fibroblasts (CAFs) and prostate lymphatic and blood vessel endothelial cells (BVEC), to humanized tissue-engineered bone constructs (hTEBC) in NOD-SCID IL2Rγnull (NSG) mice. The hTEBC formed a physiologically mature organ bone which allowed homing of metastatic PCa cells. Humanization of prostate tissue had no significant effect on the tumor burden at the primary site over the 4 weeks following intraprostatic injection, yet reduced the incidence and burden of metastases in the hTEBC. Spontaneous PCa metastases were detected in the lungs and spleen with no significant differences between the humanized and non-humanized prostate groups. A significantly greater metastatic tumor burden was observed in the liver when metastasis occurred from the humanized prostate. Together, our data suggests that the presence of human-derived CAFs and BVECs in the primary PCa microenvironment influences selectively the metastatic and homing behavior of PC3 cells in this model. Our orthotopic and humanized prostate cancer model developed via convergence of cancer research and tissue engineering concepts provides an important platform to study species-specific PCa bone metastasis and to develop and test therapeutic strategies.National Health and Medical Research Council (Project Grant 1082313 awarded to B.M.H. and D.W.H.), a Worldwide Cancer Research (Project Grant WWCR 15-11563 awarded to D.W.H.), Movember Foundation and the Prostate Cancer Foundation of Australia (Movember Revolutionary Team Award to D.W.H., E.D.W., and J.A.C.) and funding from the Australian Government Department of Health, Queensland Government (APCRC-Q)

    The Red Sea, Coastal Landscapes, and Hominin Dispersals

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    This chapter provides a critical assessment of environment, landscape and resources in the Red Sea region over the past five million years in relation to archaeological evidence of hominin settlement, and of current hypotheses about the role of the region as a pathway or obstacle to population dispersals between Africa and Asia and the possible significance of coastal colonization. The discussion assesses the impact of factors such as topography and the distribution of resources on land and on the seacoast, taking account of geographical variation and changes in geology, sea levels and palaeoclimate. The merits of northern and southern routes of movement at either end of the Red Sea are compared. All the evidence indicates that there has been no land connection at the southern end since the beginning of the Pliocene period, but that short sea crossings would have been possible at lowest sea-level stands with little or no technical aids. More important than the possibilities of crossing the southern channel is the nature of the resources available in the adjacent coastal zones. There were many climatic episodes wetter than today, and during these periods water draining from the Arabian escarpment provided productive conditions for large mammals and human populations in coastal regions and eastwards into the desert. During drier episodes the coastal region would have provided important refugia both in upland areas and on the emerged shelves exposed by lowered sea level, especially in the southern sector and on both sides of the Red Sea. Marine resources may have offered an added advantage in coastal areas, but evidence for their exploitation is very limited, and their role has been over-exaggerated in hypotheses of coastal colonization

    Polysialic acid sustains cancer cell survival and migratory capacity in a hypoxic environment

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    Polysialic acid (polySia) is a unique carbohydrate polymer expressed on the surface of NCAM (neuronal cell adhesion molecule) in a number of cancers where it modulates cell-cell and cell-matrix adhesion, migration, invasion and metastasis and is strongly associated with poor clinical prognosis. We have carried out the first investigation into the effect of polySia expression on the behaviour of cancer cells in hypoxia, a key source of chemoresistance in tumours. The role of polysialylation and associated tumour cell migration and cell adhesion were studied in hypoxia, along with effects on cell survival and the potential role of HIF-1. Our findings provide the first evidence that polySia expression sustains migratory capacity and is associated with tumour cell survival in hypoxia. Initial mechanistic studies indicate a potential role for HIF-1 in sustaining polySia-mediated migratory capacity, but not cell survival. These data add to the growing body of evidence pointing to a crucial role for the polysialyltransferases (polySTs) in neuroendocrine tumour progression and provide the first evidence to suggest that polySia is associated with an aggressive phenotype in tumour hypoxia. These results have significant potential implications for polyST inhibition as an anti-metastatic therapeutic strategy and for targeting hypoxic cancer cells

    Self domestication and the evolution of language

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    Priorities for synthesis research in ecology and environmental science

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    Synthesis research in ecology and environmental science improves understanding, advances theory, identifies research priorities, and supports management strategies by linking data, ideas, and tools. Accelerating environmental challenges increases the need to focus synthesis science on the most pressing questions. To leverage input from the broader research community, we convened a virtual workshop with participants from many countries and disciplines to examine how and where synthesis can address key questions and themes in ecology and environmental science in the coming decade. Seven priority research topics emerged: (1) diversity, equity, inclusion, and justice (DEIJ), (2) human and natural systems, (3) actionable and use-inspired science, (4) scale, (5) generality, (6) complexity and resilience, and (7) predictability. Additionally, two issues regarding the general practice of synthesis emerged: the need for increased participant diversity and inclusive research practices; and increased and improved data flow, access, and skill-building. These topics and practices provide a strategic vision for future synthesis in ecology and environmental science

    Sex Determination:Why So Many Ways of Doing It?

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    Sexual reproduction is an ancient feature of life on earth, and the familiar X and Y chromosomes in humans and other model species have led to the impression that sex determination mechanisms are old and conserved. In fact, males and females are determined by diverse mechanisms that evolve rapidly in many taxa. Yet this diversity in primary sex-determining signals is coupled with conserved molecular pathways that trigger male or female development. Conflicting selection on different parts of the genome and on the two sexes may drive many of these transitions, but few systems with rapid turnover of sex determination mechanisms have been rigorously studied. Here we survey our current understanding of how and why sex determination evolves in animals and plants and identify important gaps in our knowledge that present exciting research opportunities to characterize the evolutionary forces and molecular pathways underlying the evolution of sex determination

    Mouth State Detection From Low-Frequency Ultrasonic Reflection

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    This paper develops, simulates and experimentally evaluates a novel method based on non-contact low frequency (LF) ultrasound which can determine, from airborne reflection, whether the lips of a subject are open or closed. The method is capable of accurately distinguishing between open and closed lip states through the use of a low-complexity detection algorithm, and is highly robust to interfering audible noise. A novel voice activity detector is implemented and evaluated using the proposed method and shown to detect voice activity with high accuracy, even in the presence of high levels of background noise. The lip state detector is evaluated at a number of angles of incidence to the mouth and under various conditions of background noise. The underlying mouth state detection technique relies upon an inaudible LF ultrasonic excitation, generated in front of the face of a user, either reflecting back from their face as a simple echo in the closed mouth state or resonating inside the open mouth and vocal tract, affecting the spectral response of the reflected wave when the mouth is open. The difference between echo and resonance behaviours is used as the basis for automated lip opening detection, which implies determining whether the mouth is open or closed at the lips. Apart from this, potential applications include use in voice generation prosthesis for speech impaired patients, or as a hands-free control for electrolarynx and similar rehabilitation devices. It is also applicable to silent speech interfaces and may have use for speech authentication

    A retrospective analysis to explore the applicability of fish biomarkers and sediment bioassays along contaminated salinity transects

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    Biological-effects monitoring in estuarine environments is complex as a result of strong gradients and fluctuations in salinity and other environmental conditions, which may influence contaminant bioavailability and the physiology and metabolism of the organisms. To select the most robust and reliable biological-effect methods for monitoring and assessment programmes, a large-scale field study was conducted in two estuarine transects in the Netherlands. The locations ranged from heavily polluted harbour areas (the ports of Rotterdam and Amsterdam) to cleaner coastal and freshwater sites. Assessment methods used included a variety of biomarkers in flounder (Platichthys flesus) and a range of in vitro (sediment extracts) and in vivo bioassays. Multivariate statistical analysis was applied to investigate correlations and relationships between various biological effects and contaminant levels in flounder liver or sediments. Several biological methods seemed to be too much affected by salinity differences for routine use in estuaries. The most discriminative biomarkers in the study were hepatic metallothionein content and biliary 1-OH pyrene in fish. Mechanism-based in vitro assays DR-CALUX and ER-CALUX applied to sediment extracts for screening of potential toxicity were much more responsive than in vivo bioassays with macro-invertebrates using survival as an endpoin
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