Hypoxia-Mediated ATF4 Induction Promotes Survival in Detached Conditions in Metastatic Murine Mammary Cancer Cells

Regions of hypoxia are common in solid tumors and drive changes in gene expression that increase risk of cancer metastasis. Tumor cells must respond to the stress of hypoxia by activating genes to modify cell metabolism and antioxidant response to improve survival. The goal of the current study was to determine the effect of hypoxia on cell metabolism and markers of oxidative stress in metastatic (metM-Wntlung) compared with nonmetastatic (M-Wnt) murine mammary cancer cell lines. We show that hypoxia induced a greater suppression of glutamine to glutamate conversion in metastatic cells (13% in metastatic cells compared to 7% in nonmetastatic cells). We also show that hypoxia increased expression of genes involved in antioxidant response in metastatic compared to nonmetastatic cells, including glutamate cysteine ligase catalytic and modifier subunits and malic enzyme 1. Interestingly, hypoxia increased the mRNA level of the transaminase glutamic pyruvic transaminase 2 (Gpt2, 7.7-fold) only in metM-Wntlung cells. The change in Gpt2 expression was accompanied by transcriptional (4.2-fold) and translational (6.5-fold) induction of the integrated stress response effector protein activating transcription factor 4 (ATF4). Genetic depletion ATF4 demonstrated importance of this molecule for survival of hypoxic metastatic cells in detached conditions. These findings indicate that more aggressive, metastatic cancer cells utilize hypoxia for metabolic reprogramming and induction of antioxidant defense, including activation of ATF4, for survival in detached conditions

Rapid establishment of the European Bank for induced Pluripotent Stem Cells (EBiSC):The Hot Start experience

A fast track “Hot Start” process was implemented to launch the European Bank for Induced Pluripotent Stem Cells (EBiSC) to provide early release of a range of established control and disease linked human induced pluripotent stem cell (hiPSC) lines. Established practice amongst consortium members was surveyed to arrive at harmonised and publically accessible Standard Operations Procedures (SOPs) for tissue procurement, bio-sample tracking, iPSC expansion, cryopreservation, qualification and distribution to the research community. These were implemented to create a quality managed foundational collection of lines and associated data made available for distribution. Here we report on the successful outcome of this experience and work flow for banking and facilitating access to an otherwise disparate European resource, with lessons to benefit the international research community. eTOC: The report focuses on the EBiSC experience of rapidly establishing an operational capacity to procure, bank and distribute a foundational collection of established hiPSC lines. It validates the feasibility and defines the challenges of harnessing and integrating the capability and productivity of centres across Europe using commonly available resources currently in the field

Genetics, phylogeny, and biogeography of the marten (Martes americana)

The purpose of this study was to examine the genetic variation within a small reintroduced population of American pine marten (Martes americana) in Terra Nova National Park, Newfoundland, as well as the variation and diversity within and among other North American pine marten and closely related species. DNA sequencing of several hundred base pairs of the 5' most end of the cytochrome b gene of the mitochonrdial DNA was completed and the sequences analysed. -- It was determined that a reintroduced population and the source population shared identical DNA, based on 307 base pairs of data. A 401 base pair data base was compiled from samples of 12 subspecies of American pine marten (Martes americana) as well as European pine marten (M. martes), sable (M. zibellina), and American badger (Taxidea taxus). Genetic diversity was detected between certain subspecies of Martes americana as well as between all species of Martes studied. Two distinct lineages of Martes americana are apparent in North America ["americana" and "caurina" groups] whose pairwise sequence divergence is 1.5%. The two genetic groups correspond to the two former North American pine marten species Martes caurina and Martes americana. The average nucleon diversity (h) within the "americana" group is 0.22 and within the "caurina" group is 0.72

Porting the synthetic D-glucaric acid pathway fromEscherichia colito Saccharomyces cerevisiae

D-Glucaric acid can be produced as a value-added chemical from biomass through a de novo pathway in Escherichia coli. However, previous studies have identified pH-mediated toxicity at product concentrations of 5 g/L and have also found the eukaryotic myo-inositol oxygenase (MIOX) enzyme to be rate-limiting. We ported this pathway to Saccaromyces cerevisiae, which is naturally acid-tolerant and evaluate a codon-optimized MIOX homologue. We constructed two engineered yeast strains that were distinguished solely by their MIOX gene – either the previous version from Mus musculus or a homologue from Arabidopsis thaliana codon-optimized for expression in S. cerevisiae – in order to identify the rate-limiting steps for D-glucaric acid production both from a fermentative and non-fermentative carbon source. myo-Inositol availability was found to be rate-limiting from glucose in both strains and demonstrated to be dependent on growth rate, whereas the previously used M. musculus MIOX activity was found to be rate-limiting from glycerol. Maximum titers were 0.56 g/L from glucose in batch mode, 0.98 g/L from glucose in fed-batch mode, and 1.6 g/L from glucose supplemented with myo-inositol. Future work focusing on the MIOX enzyme, the interplay between growth and production modes, and promoting aerobic respiration should further improve this pathway. Keywords: Biochemical engineering; Bioprocess development; D-glucaric acid; Myo-inositol; YeastNational Science Foundation (U.S.) (Grant MCB‐1330914

Alcohol Advertising on Social Media: Examining the Content of Popular Alcohol Brands on Instagram

Background: There is considerable evidence that exposure to alcohol marketing increases the likelihood of adolescents initiating and engaging in alcohol consumption. There is a paucity of research, however, specifically examining industry generated alcohol marketing occurring on social media/networking platforms. Objective: The purpose of this investigation was to analyze the content of promotional advertisements by alcohol brands on Instagram. Methods: For a 30-day period, Instagram profiles of 15 distinct alcohol brands were examined. Pictorial posts/updates from each profile were screen captured and individually documented. Approximately 184 distinct posts constituted our final sample. The Content Appealing to Youth Index was independently employed by two raters to assess each post. For each characteristic, Cohen\u27s Kappa measures, and associated 95% confidence intervals, were calculated. Descriptive statistics were performed. Results: Posts increased throughout the week and peaked on Thursday and Friday. The production value of the posts examined was generally high, frequently featuring color, texture, shine, contrast, faces, and action. Character appeals and use of youth-oriented genres were uncommon. Many of the posts used product appeals and physical benefits to consumption. The posts also emphasized the following rewarding appeal characteristics: positive emotional experiences, achievement, individuality, and camaraderie. The most commonly coded risk-related feature was inappropriate use. Conclusions/Importance: This investigation represents an initial attempt to provide insights into the content alcohol brands are including in their promotional materials on social networking sites

Clustered Mutations in Yeast and in Human Cancers Can Arise from Damaged Long Single-Strand DNA Regions

Mutations are typically perceived as random, independent events. We describe here non-random clustered mutations in yeast and in human cancers. Genome sequencing of yeast grown under chronic alkylation damage identified mutation clusters that extend up to 200 kb. A predominance of “strand-coordinated” changes of either cytosines or guanines in the same strand, mutation patterns and genetic controls indicated that simultaneous mutations were generated by base alkylation in abnormally long single-strand (ss)DNA formed at double-strand breaks (DSBs) and replication forks. Significantly, we found mutation clusters with analogous features in sequenced human cancers. Strand-coordinated clusters of mutated cytosines or guanines often resided near chromosome rearrangement breakpoints and were highly enriched with a motif targeted by APOBEC family cytosine-deaminases, which strongly prefer ssDNA. These data indicate that hyper-mutation via multiple simultaneous changes in randomly formed ssDNA is a general phenomenon that may be an important mechanism producing rapid genetic variation

Optimal Architectures and Survey Designs for Maximizing the Yields of Direct-Imaging Exoplanet Missions

Our ability to answer scientific questions about exoplanets hinges on satisfying an age-old astronomical requirement: a sufficient sample size. Thus, the yield of exoplanets is critical to understanding the scientific impact of future missions. We discuss how the yield of directly-imaged exoplanets depends on mission scale and survey design