41 research outputs found

    Applications of metabolomics in cancer research

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    The first discovery of metabolic changes in cancer occurred almost a century ago. While the genetic underpinnings of cancer have dominated its study since then, altered metabolism has recently been acknowledged as a key hallmark of cancer and metabolism-focused research has received renewed attention. The emerging field of metabolomics - which attempts to profile all metabolites within a cell or biological system - is now being used to analyze cancer metabolism on a system-wide scale, painting a broad picture of the altered pathways and their interactions with each other. While a large fraction of cancer metabolomics research is focused on finding diagnostic biomarkers, metabolomics is also being used to obtain more fundamental mechanistic insight into cancer and carcinogenesis. Applications of metabolomics are also emerging in areas such as tumor staging and assessment of treatment efficacy. This review summarizes contributions that metabolomics has made in cancer research and presents the current challenges and potential future directions within the field

    The Metabolomics Society-Current State of the Membership and Future Directions.

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    Background: In 2017, the Metabolomics Society conducted a survey among its members to assess the degree of its current success, define opportunities for improving its service to the community and make plans to establish future goals and direction of the Society. Methods: A 32-question online survey was sent via e-mail to all Metabolomics Society members as of 19 June 2017 (n = 644). In addition to the direct e-mails, the link to access the survey was made available through social media. The survey was open until 10 August 2017. Question-specific data were reported using the summary data generated by SurveyMonkey and additional stratified analyses performed using Stata 15. Results: The number of respondents was 394 (61%) with 348 (88%) completing the multiple-choice questions in survey. Metabolomics Society annual meetings, networking and the opportunity to join the global metabolomics community were among the most important benefits expressed by the Metabolomics Society members. Conclusions: The survey collected the first data focusing on membership issues from Society members. The Society should focus on collecting and monitoring of demographic data during the membership registration process; continuing to support the early-career members of the Society; and developing initiatives that focus on member networking to retain and increase Society membership

    Systematic Applications of Metabolomics in Metabolic Engineering

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    The goals of metabolic engineering are well-served by the biological information provided by metabolomics: information on how the cell is currently using its biochemical resources is perhaps one of the best ways to inform strategies to engineer a cell to produce a target compound. Using the analysis of extracellular or intracellular levels of the target compound (or a few closely related molecules) to drive metabolic engineering is quite common. However, there is surprisingly little systematic use of metabolomics datasets, which simultaneously measure hundreds of metabolites rather than just a few, for that same purpose. Here, we review the most common systematic approaches to integrating metabolite data with metabolic engineering, with emphasis on existing efforts to use whole-metabolome datasets. We then review some of the most common approaches for computational modeling of cell-wide metabolism, including constraint-based models, and discuss current computational approaches that explicitly use metabolomics data. We conclude with discussion of the broader potential of computational approaches that systematically use metabolomics data to drive metabolic engineering

    Metabolomics Analysis of the Toxic Effects of the Production of Lycopene and Its Precursors

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    Using cells as microbial factories enables highly specific production of chemicals with many advantages over chemical syntheses. A number of exciting new applications of this approach are in the area of precision metabolic engineering, which focuses on improving the specificity of target production. In recent work, we have used precision metabolic engineering to design lycopene-producing Escherichia coli for use as a low-cost diagnostic biosensor. To increase precursor availability and thus the rate of lycopene production, we heterologously expressed the mevalonate pathway. We found that simultaneous induction of these pathways increases lycopene production, but induction of the mevalonate pathway before induction of the lycopene pathway decreases both lycopene production and growth rate. Here, we aim to characterize the metabolic changes the cells may be undergoing during expression of either or both of these heterologous pathways. After establishing an improved method for quenching E. coli for metabolomics analysis, we used two-dimensional gas chromatography coupled to mass spectrometry (GCxGC-MS) to characterize the metabolomic profile of our lycopene-producing strains in growth conditions characteristic of our biosensor application. We found that the metabolic impacts of producing low, non-toxic levels of lycopene are of much smaller magnitude than the typical metabolic changes inherent to batch growth. We then used metabolomics to study differences in metabolism caused by the time of mevalonate pathway induction and the presence of the lycopene biosynthesis genes. We found that overnight induction of the mevalonate pathway was toxic to cells, but that the cells could recover if the lycopene pathway was not also heterologously expressed. The two pathways appeared to have an antagonistic metabolic effect that was clearly reflected in the cells’ metabolic profiles. The metabolites homocysteine and homoserine exhibited particularly interesting behaviors and may be linked to the growth inhibition seen when the mevalonate pathway is induced overnight, suggesting potential future work that may be useful in engineering increased lycopene biosynthesis

    Bacillus subtilis engineered for topical delivery of an antifungal agent.

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    Fungal skin infections are a common condition affecting 20-25 percent of the world population. While these conditions are treatable with regular application of an antifungal medication, we sought to develop a more convenient, longer-lasting topical antifungal platform that could increase patient adherence to treatment regimens by using Bacillus subtilis, a naturally antifungal bacteria found on the skin, for drug production and delivery. In this study, we engineered B. subtilis for increased production of the antifungal lipopeptide iturin A by overexpression of the pleiotropic regulator DegQ. The engineered strain had an over 200% increase in iturin A production as detected by HPLC, accompanied by slower growth but the same terminal cell density as determined by absorbance measurements of liquid culture. In an in vitro antifungal assay, we found that despite its higher iturin A production, the engineered strain was less effective at reducing the growth of a plug of the pathogenic fungus Trichophyton mentagrophytes on an agar plate compared to the parent strain. The reduced efficacy of the engineered strain may be explained by its reduced growth rate, which highlights the need to address trade-offs between titers (e.g. measured drug production) and other figures of merit (e.g. growth rate) during metabolic engineering

    Development of a Pigment-Based Whole-Cell Zinc Biosensor for Human Serum

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    Deficiencies in vitamins and minerals (micronutrients) are a critical global health concern, in part due to logistical difficulties in assessing population micronutrient status. Whole-cell biosensors offer a unique opportunity to address this issue, with the potential to move sample analysis from centralized, resource-intensive clinics to minimal-resource, on-site measurement. Here, we present a proof-of-concept whole-cell biosensor in Escherichia coli for detecting zinc, a micronutrient for which deficiencies are a significant public health burden. Importantly, the whole-cell biosensor produces readouts (pigments) that are visible to the naked eye, mitigating the need for measurement equipment and thus increasing feasibility for sensor field-friendliness and affordability at a global scale. Two zinc-responsive promoter/transcription factor systems are used to differentially control production of three distinctly colored pigments in response to zinc levels in culture. We demonstrate strategies for tuning each zinc-responsive system to turn production of the different pigments on and off at different zinc levels, and we demonstrate production of three distinct color regimes over a concentration range relevant to human health. We also demonstrate the ability of the sensor cells to grow and produce pigment when cultured in human serum, the ultimate target matrix for assessing zinc nutritional status. Specifically, we present approaches to overcome innate immune responses that would otherwise hinder bacterial sensor survival, and we demonstrate production of multiple pigment regimes in human serum with different zinc levels. This work provides proof of principle for the development of low-cost, minimal-equipment, field-deployable biosensors for nutritional epidemiology applications

    Development of a Pigment-Based Whole-Cell Zinc Biosensor for Human Serum

    No full text
    Deficiencies in vitamins and minerals (micronutrients) are a critical global health concern, in part due to logistical difficulties in assessing population micronutrient status. Whole-cell biosensors offer a unique opportunity to address this issue, with the potential to move sample analysis from centralized, resource-intensive clinics to minimal-resource, on-site measurement. Here, we present a proof-of-concept whole-cell biosensor in Escherichia coli for detecting zinc, a micronutrient for which deficiencies are a significant public health burden. Importantly, the whole-cell biosensor produces readouts (pigments) that are visible to the naked eye, mitigating the need for measurement equipment and thus increasing feasibility for sensor field-friendliness and affordability at a global scale. Two zinc-responsive promoter/transcription factor systems are used to differentially control production of three distinctly colored pigments in response to zinc levels in culture. We demonstrate strategies for tuning each zinc-responsive system to turn production of the different pigments on and off at different zinc levels, and we demonstrate production of three distinct color regimes over a concentration range relevant to human health. We also demonstrate the ability of the sensor cells to grow and produce pigment when cultured in human serum, the ultimate target matrix for assessing zinc nutritional status. Specifically, we present approaches to overcome innate immune responses that would otherwise hinder bacterial sensor survival, and we demonstrate production of multiple pigment regimes in human serum with different zinc levels. This work provides proof of principle for the development of low-cost, minimal-equipment, field-deployable biosensors for nutritional epidemiology applications

    The intelligent design of evolution

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