Protein and lipid MALDI profiles classify breast cancers according to the intrinsic subtype

<p>Abstract</p> <p>Background</p> <p>Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) has been demonstrated to be useful for molecular profiling of common solid tumors. Using recently developed MALDI matrices for lipid profiling, we evaluated whether direct tissue MALDI MS analysis on proteins and lipids may classify human breast cancer samples according to the intrinsic subtype.</p> <p>Methods</p> <p>Thirty-four pairs of frozen, resected breast cancer and adjacent normal tissue samples were analyzed using histology-directed, MALDI MS analysis. Sinapinic acid and 2,5-dihydroxybenzoic acid/α-cyano-4-hydroxycinnamic acid were manually deposited on areas of each tissue section enriched in epithelial cells to identify lipid profiles, and mass spectra were acquired using a MALDI-time of flight instrument.</p> <p>Results</p> <p>Protein and lipid profiles distinguish cancer from adjacent normal tissue samples with the median prediction accuracy of 94.1%. Luminal, HER2+, and triple-negative tumors demonstrated different protein and lipid profiles, as evidenced by permutation <it>P </it>values less than 0.01 for 0.632+ bootstrap cross-validated misclassification rates with all classifiers tested. Discriminatory proteins and lipids were useful for classifying tumors according to the intrinsic subtype with median prediction accuracies of 80.0-81.3% in random test sets.</p> <p>Conclusions</p> <p>Protein and lipid profiles accurately distinguish tumor from adjacent normal tissue and classify breast cancers according to the intrinsic subtype.</p

Docosahexaenoic acid promotes micron scale liquid-ordered domains. A comparison study of docosahexaenoic versus oleic acid- containing phosphatidylcholine in raft-like mixtures.

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Sensory and instrumental texture analysis of Bulgarian commercial pates

Abstract. The aim of this study was to characterize the textural differences between Bulgarian commercial pates with different ingredients and to adapt the used methods for later application in texture analysis of sterilized meat products. Texture parameters were studied by sensory and instrumental methods. The sensory panel was stated from students in similar age and was asked to fulfill a questionnaire about their likening the poultry pates bought from the commercial network. Nine points sensory scales were used, about appearance, colour, spreadability by knife to bread, flavor, consistency, taste, aftertaste and overall likening. The panelists were asked to rank the pates based on their colour, spreadability and consistency. Instrumental texture parameters – texture profile and spreadability work, were analyzed by Stable Micro Systems texture analyzer in Texture Profile Analysis (TPA) and compression methods. For further analysis of spreadability, the probes were scanned by flatbed scanner before and after compression and their area ratio was measured by image analysis method. The results of sensory analysis show that, the pate with duck meat received the highest liking based on the overall liking, followed by pate with turkey meat and pate from chicken meat and liver and the lowest liked was the pate with goose meat. Based on the sensory spreadability and consistency the hardest was the pate with goose meat followed by pate with turkey meat and pate from chicken meat and liver and the softest was the pate with duck meat. The results from instrumental spreadability and hardness showed positive correlations with the results of the sensory analysis

Protein thermal sensing regulates physiological amyloid aggregation

Abstract To survive, cells must respond to changing environmental conditions. One way that eukaryotic cells react to harsh stimuli is by forming physiological, RNA-seeded subnuclear condensates, termed amyloid bodies (A-bodies). The molecular constituents of A-bodies induced by different stressors vary significantly, suggesting this pathway can tailor the cellular response by selectively aggregating a subset of proteins under a given condition. Here, we identify critical structural elements that regulate heat shock-specific amyloid aggregation. Our data demonstrates that manipulating structural pockets in constituent proteins can either induce or restrict their A-body targeting at elevated temperatures. We propose a model where selective aggregation within A-bodies is mediated by the thermal stability of a protein, with temperature-sensitive structural regions acting as an intrinsic form of post-translational regulation. This system would provide cells with a rapid and stress-specific response mechanism, to tightly control physiological amyloid aggregation or other cellular stress response pathways

An ellipsometric study of interaction of anti-cancer agent erufosine on lipid model systems

The study of the interaction of native and model lipid membranes with pharmacological agents is a subject of outstanding interest in the research of biomaterials, biosensors, the production of devices using organic layers. In last few years, the study of biomimetic membrane systems in the form of vesicles, lipid monolayers and solid-supported lipid layers has attracted a significant attention among researchers. In this work, we present a capability of the spectroscopic ellipsometry as a novel technique to study solid - supported lipid model systems and decode the effect of the anti-cancer agent erufosine on lipids. Importantly, this technique has been proved as a fast and non-invasive method. The lipid films are composed of phosphatidylcholine, sphingomyelin and cholesterol in different concentrations and we have employed a thin gold film for supporting their surface. Erufosine (EPC3) is known as membrane-acting anti-tumor agent and in this respect has been investigated its effect on the model systems. The obtained results have revealed reorganization of lipid layers at different extent by interaction with the anti-cancer agent.Acknowledge the financial support of EC ERASMUS MUNDUS: NANOPHI and FNI, DN 11/1/2017 projects