79 research outputs found

    Expression analysis of secreted and cell surface genes of five transformed human cell lines and derivative xenograft tumors

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    BACKGROUND: Since the early stages of tumorigenesis involve adhesion, escape from immune surveillance, vascularization and angiogenesis, we devised a strategy to study the expression profiles of all publicly known and putative secreted and cell surface genes. We designed a custom oligonucleotide microarray containing probes for 3531 secreted and cell surface genes to study 5 diverse human transformed cell lines and their derivative xenograft tumors. The origins of these human cell lines were lung (A549), breast (MDA MB-231), colon (HCT-116), ovarian (SK-OV-3) and prostate (PC3) carcinomas. RESULTS: Three different analyses were performed: (1) A PCA-based linear discriminant analysis identified a 54 gene profile characteristic of all tumors, (2) Application of MANOVA (Pcorr < .05) to tumor data revealed a larger set of 149 differentially expressed genes. (3) After MANOVA was performed on data from individual tumors, a comparison of differential genes amongst all tumor types revealed 12 common differential genes. Seven of the 12 genes were identified by all three analytical methods. These included late angiogenic, morphogenic and extracellular matrix genes such as ANGPTL4, COL1A1, GP2, GPR57, LAMB3, PCDHB9 and PTGER3. The differential expression of ANGPTL4 and COL1A1 and other genes was confirmed by quantitative PCR. CONCLUSION: Overall, a comparison of the three analyses revealed an expression pattern indicative of late angiogenic processes. These results show that a xenograft model using multiple cell lines of diverse tissue origin can identify common tumorigenic cell surface or secreted molecules that may be important biomarker and therapeutic discoveries

    Looking to peripheral river islands in Brazil to develop an urban island water metabolism perspective.

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    Across Brazil, including the water rich Amazon region, access to safe drinking water remains a challenge and rainwater harvesting has gained credibility as a technological solution. Complementing a more techno-centric approach, this practice paper analyses initial findings from an 'immersion' that was undertaken in August 2017 on Paquetá and surrounding islands located on the periphery of Belém (Schiffer and Swan, 2018), through the proposed urban island water metabolism framework. As such, the research draws on the 'urban metabolism' concept which can be described as socio-technical, socio-economic, socio-political and socio-ecological flows including water resources, people and information in, out and within the urban environment (Currie and Musango, 2016; Kennedy, Cuddihy and Engel-Yan, 2007). Here this has been adapted to 'urban island water metabolisms'. The research highlights the value of more holistic and situated understanding of water systems in urban island contexts including: the role of intra-island networks that operate beyond municipal borders; accessibility in the contexts of ever changing water levels; and seasonal dimensions. The paper recommends longer-term and comparative research to further the understanding of the specific needs and challenges for water management in these peripheral contexts and to strengthen the urban island water metabolism concept

    Leptin concentrations in response to acute stress predict subsequent intake of comfort foods

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    Both animals and humans show a tendency toward eating more “comfort food” (high fat, sweet food) after acute stress. Such stress eating may be contributing to the obesity epidemic, and it is important to understand the underlying psychobiological mechanisms. Prior investigations have studied what makes individuals eat more after stress; this study investigates what might make individuals eat less. Leptin has been shown to increase following a laboratory stressor, and is known to affect eating behavior. This study examined whether leptin reactivity accounts for individual differences in stress eating. To test this, we exposed forty women to standardized acute psychological laboratory stress (Trier Social Stress Test) while blood was sampled repeatedly for measurements of plasma leptin. We then measured food intake after the stressor in 29 of these women. Increasing leptin during the stressor predicted lower intake of comfort food. These initial findings suggest that acute changes in leptin may be one of the factors modulating down the consumption of comfort food following stress
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