bims-mascan Biomed News
on Mass spectrometry in cancer research
Issue of 2024‒09‒22
25 papers selected by
Giovanny Rodriguez Blanco, University of Edinburgh



  1. Cold Spring Harb Perspect Med. 2024 Sep 16. pii: a041553. [Epub ahead of print]
      It is increasingly appreciated that cancer cells adapt their metabolic pathways to support rapid growth and proliferation as well as survival, often even under the poor nutrient conditions that characterize some tumors. Cancer cells can also rewire their metabolism to circumvent chemotherapeutics that inhibit core metabolic pathways, such as nucleotide synthesis. A critical approach to the study of cancer metabolism is metabolite profiling (metabolomics), the set of technologies, usually based on mass spectrometry, that allow for the detection and quantification of metabolites in cancer cells and their environments. Metabolomics is a burgeoning field, driven by technological innovations in mass spectrometers, as well as novel approaches to isolate cells, subcellular compartments, and rare fluids, such as the interstitial fluid of tumors. Here, we discuss three emerging metabolomic technologies: spatial metabolomics, single-cell metabolomics, and organellar metabolomics. The use of these technologies along with more established profiling methods, like single-cell transcriptomics and proteomics, is likely to underlie new discoveries and questions in cancer research.
    DOI:  https://doi.org/10.1101/cshperspect.a041553
  2. Mol Cell Proteomics. 2024 Sep 13. pii: S1535-9476(24)00130-0. [Epub ahead of print] 100840
      Analysis of large-scale data-independent acquisition mass spectrometry (DIA-MS) metaproteomics data remains a computational challenge. Here, we present a computational pipeline called metaExpertPro for metaproteomics data analysis. This pipeline encompasses spectral library generation using data-dependent acquisition MS (DDA-MS), protein identification and quantification using DIA-MS, functional and taxonomic annotation, as well as quantitative matrix generation for both microbiota and hosts. By integrating FragPipe and DIA-NN, metaExpertPro offers compatibility with both Orbitrap and timsTOF MS instruments. To evaluate the depth and accuracy of identification and quantification, we conducted extensive assessments using human fecal samples and benchmark tests. Performance tests conducted on human fecal samples indicated that metaExpertPro quantified an average of 45,000 peptides in a 60-minute diaPASEF injection. Notably, metaExpertPro outperformed three existing software tools by characterizing a higher number of peptides and proteins. Importantly, metaExpertPro maintained a low factual false discovery rate (FDR) of approximately 5% for protein groups across four benchmark tests. Applying a filter of five peptides per genus, metaExpertPro achieved relatively high accuracy (F-score = 0.67-0.90) in genus diversity and showed a high correlation (rSpearman = 0.73-0.82) between the measured and true genus relative abundance in benchmark tests. Additionally, the quantitative results at the protein, taxonomy, and function levels exhibited high reproducibility and consistency across the commonly adopted public human gut microbial protein databases IGC and UHGP. In a metaproteomic analysis of dyslipidemia (DLP) patients, metaExpertPro revealed characteristic alterations in microbial functions and potential interactions between the microbiota and the host.
    DOI:  https://doi.org/10.1016/j.mcpro.2024.100840
  3. Dis Model Mech. 2024 Sep 01. pii: dmm050814. [Epub ahead of print]17(9):
      Cancer cells require a constant supply of lipids. Lipids are a diverse class of hydrophobic molecules that are essential for cellular homeostasis, growth and survival, and energy production. How tumors acquire lipids is under intensive investigation, as these mechanisms could provide attractive therapeutic targets for cancer. Cellular lipid metabolism is tightly regulated and responsive to environmental stimuli. Thus, lipid metabolism in cancer is heavily influenced by the tumor microenvironment. In this Review, we outline the mechanisms by which the tumor microenvironment determines the metabolic pathways used by tumors to acquire lipids. We also discuss emerging literature that reveals that lipid availability in the tumor microenvironment influences many metabolic pathways in cancers, including those not traditionally associated with lipid biology. Thus, metabolic changes instigated by the tumor microenvironment have 'ripple' effects throughout the densely interconnected metabolic network of cancer cells. Given the interconnectedness of tumor metabolism, we also discuss new tools and approaches to identify the lipid metabolic requirements of cancer cells in the tumor microenvironment and characterize how these requirements influence other aspects of tumor metabolism.
    Keywords:  Acidosis; Diet; Hypoxia; Lipid metabolism; Nutrient deprivation; Tumor microenvironment
    DOI:  https://doi.org/10.1242/dmm.050814
  4. J Am Soc Mass Spectrom. 2024 Sep 14.
      Global discovery lipidomics can provide comprehensive chemical information toward understanding the intricacies of metabolic lipid disorders such as dyslipidemia; however, the isomeric complexity of lipid species remains an analytical challenge. Orthogonal separation strategies, such as ion mobility (IM), can be inserted into liquid chromatography-mass spectrometry (LC-MS) untargeted lipidomic workflows for additional isomer separation and high-confidence annotation, and the emergence of high-resolution ion mobility (HRIM) strategies provides marked improvements to the resolving power (Rp > 200) that can differentiate small structural differences characteristic of isomers. One such HRIM strategy, high-resolution demultiplexing (HRdm), utilizes multiplexed drift tube ion mobility spectrometry (DTIMS) with post-acquisition algorithmic deconvolution to access high IM resolutions while retaining the measurement precision inherent to the drift tube technique; however, HRdm has yet to be utilized in untargeted studies. In this manuscript, a proof-of-concept study using ATP10D dysfunctional murine models was investigated to demonstrate the utility of HRdm-incorporated untargeted lipidomic analysis pipelines. Total lipid features were found to increase by 2.5-fold with HRdm compared to demultiplexed DTIMS as a consequence of more isomeric lipids being resolved. An example lipid, PC 36:5, was found to be significantly higher in dysfunctional ATP10D mice with two resolved peaks observed by HRdm that were absent in both the functional ATP10D mice and the standard demultiplexed DTIMS acquisition mode. The benefits of utilizing HRdm for discerning isomeric lipids in untargeted workflows have the potential to enhance our analytical understanding of lipids related to disease complexity and biologically relevant studies.
    Keywords:  HRIM; Hadamard transform; murine dyslipidemia; peak deconvolution; untargeted lipidomics
    DOI:  https://doi.org/10.1021/jasms.4c00251
  5. Anal Chem. 2024 Sep 18.
      Capillary zone electrophoresis (CE) combines high separation power, scalability, and speed to limited proteome analyses by mass spectrometry (MS). However, compressed separation in CE challenges the duty cycle of tandem MS, even during data-independent acquisition (DIA). To help remedy this limitation, we introduce the concept of electrophoresis-correlative (Eco) data acquisition for CE-MS. We recognize CE electrospray ionization (ESI) to sort peptide ions into reproducible mass-to-charge (m/z) vs migration time (MT) trends in the solution phase, before subsequent ionization and m/z analysis. We proposed that such a correlation can be leveraged to improve the economy of data acquisition. We test this hypothesis using DIA frames that are tailored to the observed m/z-MT trends. The resulting Eco-DIA method substantially improves the bandwidth utilization of tandem MS during CE-MS. In proof-of-principle studies, Eco-DIA identified and quantified ∼38% more proteins from 1 ng of the HeLa proteome digest compared to the classical DIA, without the assistance of a project-specific tandem MS spectral library. Eco-DIA was able to quantify ∼51% more proteins with <10% coefficient of variation vs the control DIA approach. Based on label-free quantification, the proteins that were exclusively measured by Eco-MS occupied the lower dynamic range of the detected proteome concentration, revealing sensitivity enhancement. In addition to marking the inception of Eco-MS, this work lays the foundation for the development of next-generation data acquisition strategies that leverage electrophoretic ion sorting for high-sensitivity proteomics.
    DOI:  https://doi.org/10.1021/acs.analchem.4c02330
  6. ACS Chem Neurosci. 2024 Sep 20.
      Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic, complex illness characterized by severe and often disabling physical and mental fatigue. So far, scientists have not been able to fully pinpoint the biological cause of the illness and yet it affects millions of people worldwide. To gain a better understanding of ME/CFS, we compared the metabolic networks in the plasma of 38 ME/CFS patients to those of 24 healthy control participants. This involved an untargeted metabolomics approach in addition to the measurement of targeted substances including tryptophan and its metabolites, as well as tyrosine, phenylalanine, B vitamins, and hypoxanthine using liquid chromatography coupled to mass spectrometry. We observed significant alterations in several metabolic pathways, including the vitamin B3, arginine-proline, and aspartate-asparagine pathways, in the untargeted analysis. The targeted analysis revealed changes in the levels of 3-hydroxyanthranilic acid, 3-hydroxykynurenine, hypoxanthine, and phenylalanine in ME/CFS patients compared to the control group. These findings suggest potential alterations in immune system response and oxidative stress in ME/CFS patients.
    Keywords:  biomarker; high resolution mass spectrometry; metabolomics; myalgic encephalomyelitis (ME/CFS); neurodegenerative disorders; targeted analysis; untargeted analysis
    DOI:  https://doi.org/10.1021/acschemneuro.4c00444
  7. J Chromatogr B Analyt Technol Biomed Life Sci. 2024 Sep 10. pii: S1570-0232(24)00306-4. [Epub ahead of print]1247 124297
      Mycobacteria possess unique and robust lipid profile responsible for their pathogenesis and drug resistance. Mycolic acid (MA) represents an attractive diagnostic biomarker being absent in humans, inert and known to modulate host-pathogen interaction. Accurate measurement of MA is significant to design efficient therapeutics. Despite considerable advances in Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) based approaches, quantification of mycobacterial lipids including MA is still challenging mainly because of ion suppression effects due to complex matrix and non-availability of suitable internal standards for MA. The current study demonstrates the use of standard addition method (SAM) to circumvent this problem and provides a reliable and exhaustive analytical method to quantify mycobacterial MA based on reversed-phase ultra-high-performance liquid chromatography- mass spectrometry data acquisition. In this method, multiple reaction monitoring (MRM) has been applied, wherein 16 MRM channels or transitions have been chosen for quantification of alpha-, methoxy- and keto-MAs with C-24 and C-26 hydrocarbon chains that are actually best suited for TB diagnostics. We found that the overall methodological limit of detection and limit of quantification were in the range 0.05-0.71 ng/µl and 0.16-2.16 ng/µl. Taken together, SAM quantitative technique could serve as promising alternative for relative concentration determination of MA to aid medical research.
    Keywords:  LCMS; Multiple reaction monitoring; Mycobacterium tuberculosis; Mycolic acids; Standard addition method; Tuberculosis
    DOI:  https://doi.org/10.1016/j.jchromb.2024.124297
  8. mSystems. 2024 Sep 16. e0098524
      Large-scale studies are essential to answer questions about complex microbial communities that can be extremely dynamic across hosts, environments, and time points. However, managing acquisition, processing, and analysis of large numbers of samples poses many challenges, with cross-contamination being the biggest obstacle. Contamination complicates analysis and results in sample loss, leading to higher costs and constraints on mixed sample type study designs. While many researchers opt for 96-well plates for their workflows, these plates present a significant issue: the shared seal and weak separation between wells leads to well-to-well contamination. To address this concern, we propose an innovative high-throughput approach, termed as the Matrix method, which employs barcoded Matrix Tubes for sample acquisition. This method is complemented by a paired nucleic acid and metabolite extraction, utilizing 95% (vol/vol) ethanol to stabilize microbial communities and as a solvent for extracting metabolites. Comparative analysis between conventional 96-well plate extractions and the Matrix method, measuring 16S rRNA gene levels via quantitative polymerase chain reaction, demonstrates a notable decrease in well-to-well contamination with the Matrix method. Metagenomics, 16S rRNA gene amplicon sequencing (16S), and untargeted metabolomics analysis via liquid chromatography-tandem mass spectrometry (LC-MS/MS) confirmed that the Matrix method recovers reproducible microbial and metabolite compositions that can distinguish between subjects. This advancement is critical for large-scale study design as it minimizes well-to-well contamination and technical variation, shortens processing times, and integrates with automated infrastructure for enhancing sample randomization and metadata generation.IMPORTANCE: Understanding dynamic microbial communities typically requires large-scale studies. However, handling large numbers of samples introduces many challenges, with cross-contamination being a major issue. It not only complicates analysis but also leads to sample loss and increased costs and restricts diverse study designs. The prevalent use of 96-well plates for nucleic acid and metabolite extractions exacerbates this problem due to their wells having little separation and being connected by a single plate seal. To address this, we propose a new strategy using barcoded Matrix Tubes, showing a significant reduction in cross-contamination compared to conventional plate-based approaches. Additionally, this method facilitates the extraction of both nucleic acids and metabolites from a single tubed sample, eliminating the need to collect separate aliquots for each extraction. This innovation improves large-scale study design by shortening processing times, simplifying analysis, facilitating metadata curation, and producing more reliable results.
    Keywords:  cross-contamination; large-scale studies; metabolomics; microbiome; well-to-well contamination
    DOI:  https://doi.org/10.1128/msystems.00985-24
  9. Anal Chem. 2024 Sep 18.
      Nontargeted analysis (NTA) is increasingly utilized for its ability to identify key molecular features beyond known targets in complex samples. NTA is particularly advantageous in exploratory studies aimed at identifying phenotype-associated features or molecules able to classify various sample types. However, implementing NTA involves extensive data analyses and labor-intensive annotations. To address these limitations, we developed a rapid data screening capability compatible with NTA data collected on a liquid chromatography, ion mobility spectrometry, and mass spectrometry (LC-IMS-MS) platform that allows for sample classification while highlighting potential features of interest. Specifically, this method aggregates the thousands of IMS-MS spectra collected across the LC space for each sample and collapses the LC dimension, resulting in a single summed IMS-MS spectrum for screening. The summed IMS-MS spectra are then analyzed with a bootstrapped Lasso technique to identify key regions or coordinates for phenotype classification via support vector machines. Molecular annotations are then performed by examining the features present in the selected coordinates, highlighting potential molecular candidates. To demonstrate this summed IMS-MS screening approach, we applied it to clinical plasma lipidomic NTA data and exposomic NTA data from water sites with varying contaminant levels. Distinguishing coordinates were observed in both studies, enabling the evaluation of phenotypic molecular annotations and resulting in screening models capable of classifying samples with up to a 25% increase in accuracy compared to models using annotated data.
    DOI:  https://doi.org/10.1021/acs.analchem.4c03256
  10. Best Pract Res Clin Endocrinol Metab. 2024 Sep 05. pii: S1521-690X(24)00110-6. [Epub ahead of print] 101935
      The complexity of omes - the key cellular ensembles (genome and epigenome, transcriptome, proteome, and metabolome) - is becoming increasingly understood in terms of big-data analysis, the omics. Amongst these, proteomics provides a global description of quantitative and qualitative alterations of protein expression (or protein abundance in body fluids) in response to physiologic or pathologic processes while metabolomics offers a functional portrait of the physiological state by quantifying metabolite abundances in biological samples. Here, we summarize how different techniques of proteomic and metabolic analysis can be used to define key biochemical characteristics of pheochromocytomas/paragangliomas (PPGL). The significance of omics in understanding features of PPGL biology that might translate to improved diagnosis and treatment will be highlighted.
    Keywords:  liquid chromatography; mass spectrometry; metabolome; nuclear magnetic resonance spectroscopy; oncometabolites; proteome
    DOI:  https://doi.org/10.1016/j.beem.2024.101935
  11. Cold Spring Harb Perspect Med. 2024 Sep 16. pii: a041532. [Epub ahead of print]
      Rapidly proliferating cells, including cancer cells, adapt metabolism to meet the increased energetic and biosynthetic demands of cell growth and division. Many rapidly proliferating cells exhibit increased glucose consumption and fermentation regardless of oxygen availability, a phenotype termed aerobic glycolysis or the Warburg effect in cancer. Several explanations for why cells engage in aerobic glycolysis and how it supports proliferation have been proposed, but none can fully explain all conditions and data where aerobic glycolysis is observed. Nevertheless, there is convincing evidence that the Warburg effect is important for the proliferation of many cancers, and that inhibiting either glucose uptake or fermentation can impair tumor growth. Here, we discuss what is known about metabolism associated with aerobic glycolysis and the evidence supporting various explanations for why aerobic glycolysis may be important in cancer and other contexts.
    DOI:  https://doi.org/10.1101/cshperspect.a041532
  12. Rapid Commun Mass Spectrom. 2024 Nov 30. 38(22): e9892
      RATIONALE: Heavy-labelled internal standards increasingly represent the gold standard for absolute quantitation in mass spectrometry (MS)-based bottom-up proteomics. The biggest drawbacks of using these standards are that they have high costs and lengthy lead times.METHODS: We describe an efficient, low-cost optimised method to enable 'in-house' heavy labelling of synthetic tryptic peptides for absolute quantification using tandem LC-MS/MS mass spectrometry. Our methodology uses 18O water in a trypsin-catalysed oxygen exchange reaction at the carboxyl terminus with the overall aim of reducing the costs and lead time associated with sourcing heavy standards from commercial vendors.
    RESULTS: Step-by-step instructions are provided on how to execute this protocol with high-throughput adaptations utilising a 96-well plate and a liquid-handling robot. Detailed notes on experimental setup, tips for troubleshooting and suggested improvements to maximise labelling efficiencies are highlighted to achieve the best results. Under optimum conditions, labelling efficiencies of peptides can reach from 95% to 100%.
    CONCLUSIONS: The application of the 'in-house' labelled standards in generating calibration curves to quantify endogenous peptide concentrations is just as effective as using the synthetically sourced standards while also having great cost reduction implications as well as saving time spent waiting for peptides to arrive. The protocol is highly adaptable and can be customized to fit the specific setup of any laboratory, maximizing achievable labelling efficiencies.
    DOI:  https://doi.org/10.1002/rcm.9892
  13. J Chromatogr B Analyt Technol Biomed Life Sci. 2024 Sep 12. pii: S1570-0232(24)00317-9. [Epub ahead of print]1247 124308
      A selective and sensitive liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method was developed and validated for simultaneous quantitation of a cassette of 8 drugs, including docetaxel, erlotinib, loperamide, riluzole, vemurafenib, verapamil, elacridar and tariquidar. Stable isotopically labeled compounds were available for use as internal standards for all compounds, except for tariquidar for which we used elacridar-d4. Sample pre-treatment involved liquid-liquid extraction using tert-butyl-methyl ether as this resulted in good recovery and low ion suppression. Chromatographic separation was achieved using a Zorbax Extend C18 analytical column and a linear gradient from 20 % to 95 % methanol in 0.1 % (v/v) formic acid in water. MS/MS detection using multiple reaction monitoring was done in positive ionization mode. We validated this assay for human and mouse plasma and mouse brain homogenates. The calibration curves were linear over a range 1-200 nM for each drug in the mix, except for tariquidar probably due to the lack of a stable isotope labeled analog. The intra-day and inter-day accuracies were within the 85-115 % range for all compounds at low, medium and high concentrations in the three different matrices. Similarly, the precision for all compounds at three different concentration levels ranged below 15 %, with the exception of tariquidar in mouse plasma and brain homogenate and riluzole in brain homogenate. Pilot studies have confirmed that the method is suitable for the analysis of mouse plasma samples and brain homogenates following cassette dosing of this mixture in mice.
    Keywords:  Brain homogenate; Cassette quantitation; Human plasma; LC-MS/MS method validation; Liquid–liquid extraction; Mouse plasma
    DOI:  https://doi.org/10.1016/j.jchromb.2024.124308
  14. Cancer Res. 2024 Sep 16. 84(18): 2947-2949
      It has been known that poor tumor perfusion and dysregulated cancer cell metabolism give rise to tumor microenvironments with unphysiologic nutrient levels, but the precise alterations in metabolite abundance are not well defined. In a 2015 study in Cancer Research, Kamphorst and colleagues published a detailed comparison of the metabolome from human pancreatic tumors and benign tissues. Tumors were depleted in glucose and various nonessential amino acids but, surprisingly, enriched in essential amino acids. The authors attributed these nutrient imbalances to macropinocytosis of extracellular proteins, a RAS-driven amino acid acquisition pathway that was found to be increased in human tumors and supports pancreatic cancer cell growth during amino acid starvation. These findings substantially contributed to the understanding of altered nutrient levels in tumors and extracellular proteins as noncanonical nutrients. Intratumoral nutrient levels in different cancer contexts and signaling pathways that regulate nutrient acquisition by cancer cells remain a focus of current research. See related article by Kamphorst and colleagues, Cancer Res 2015;75:544-53.
    DOI:  https://doi.org/10.1158/0008-5472.CAN-24-2447
  15. J Chromatogr A. 2024 Sep 13. pii: S0021-9673(24)00751-9. [Epub ahead of print]1736 465377
      A nanospray emitter coupled to a supercritical fluid chromatograph (SFC-nSI-MS) for mass spectrometric (MS) analysis of fatty acids (FA) positional isomers is introduced. The experimental setup uses conventional bore columns before the SF back-pressure regulator (pre-BPR). The flow is then split and nanosprayed using a short emitter post-BPR. A C18 column was used to resolve positional isomers of unsaturated FA with a 5 min gradient. Chromatographic resolution of the nSFC was compared to a LC-MS system with superior resolving power demonstrated in the nSFC MS system. This system has proven quantitative performance for analyzing pharmaceutical effects on FA composition in a complex biological matrix like E coli lysate.
    Keywords:  Capillary LC; Duty cycle; Escherichia coli; Isomers; Metabolomics; NSFC; Nanospray; Optimization; Rapid chromatography; Resolution; SFC
    DOI:  https://doi.org/10.1016/j.chroma.2024.465377
  16. J Biol Chem. 2024 Sep 12. pii: S0021-9258(24)02273-7. [Epub ahead of print] 107772
      Lipid-rich deposits called drusen accumulate under the retinal pigment epithelium (RPE) in the eyes of patients with age-related macular degeneration (AMD) and Sorsby's fundus dystrophy (SFD). Drusen may contribute to photoreceptor and RPE degeneration in these blinding diseases. We hypothesize that stimulating β-oxidation of fatty acids could decrease the availability of lipid with which RPE cells can generate drusen. Inhibitors of acetyl-CoA carboxylase (ACC) stimulate β-oxidation and diminish lipid accumulation in fatty liver disease. In this report we test the hypothesis that an ACC inhibitor, Firsocostat, can diminish lipid deposition by RPE cells. We probed metabolism and cellular function in mouse RPE-choroid tissue and in cultured human RPE cells. We used 13C6-glucose, 13C16-palmitate, and gas chromatography-linked mass spectrometry to monitor effects of Firsocostat on glycolytic, Krebs cycle, and fatty acid metabolism. We quantified lipid abundance, apolipoprotein E (ApoE) and vascular endothelial growth factor (VEGF) release using liquid chromatography-mass spectrometry, enzyme-linked immunosorbent assays and localized ApoE deposits by immunostaining. RPE barrier function was assessed by trans-epithelial electrical resistance (TEER). Firsocostat-mediated ACC inhibition increases β-oxidation, decreases intracellular lipid levels, diminishes lipoprotein release, and increases TEER. When human serum or outer segments are used to stimulate lipoprotein release, fewer lipoproteins are released in the presence of either lipid source and Firsocostat. In a culture model of SFD, Firsocostat stimulates fatty acid oxidation, increases TEER, and decreases ApoE release. We conclude that Firsocostat remodels RPE metabolism and can limit lipid deposition. This suggests that ACC inhibition could be an effective strategy for diminishing pathologic drusen in the eyes of patients with AMD or SFD.
    Keywords:  Retinal pigment epithelium; age-related macular degeneration; apolipoprotein E (ApoE); beta‐oxidation; energy metabolism; fatty acid; retinal degeneration
    DOI:  https://doi.org/10.1016/j.jbc.2024.107772
  17. Xenobiotica. 2024 Sep 16. 1-31
      Stable isotope labeling by amino acids in cell culture (SILAC) is an established technique used in quantitative mass spectrometry (MS)-based proteomics. SILAC is also used to generate stable isotope labeled (SIL) antibodies for internal standards (IS) used in LC-MS/MS bioassays to improve quantitative robustness.Total antibody (TAb) is measured to evaluate pharmacokinetic (PK) of antibody drug conjugate (ADC) candidates measured by either ligand binding (LBA) or LC-MS/MS. Herein, we describe an application of SILAC, where multiple SIL combinations of an antibody are used for cassette dosing and PK evaluation.Our preclinical studies demonstrate SILAC-labeled ADC therapeutics did not alter antibody PK. Furthermore, with cassette dosing SIL antibodies exhibited comparable exposure to discretely administered unlabeled test articles in rats.In addition, SIL antibodies were conjugated to cytotoxic payloads to create SIL ADCs and cassette dosed in a cynomolgus monkey PK study and SIL ADCs yielded comparable PK results to discrete dosed unlabeled ADCs.In conclusion, SIL antibodies used with a cassette dosing strategy increases PK screening throughput of ADC candidates in preclinical species. Additionally, cassette dosing strategy further facilitates the responsible use of laboratory animals to achieve the three-Rs (Replacement, Reduction, and Refinement).
    Keywords:  Antibody-drug conjugate; Biologics; Cassette; Pharmacokinetics; SILAC
    DOI:  https://doi.org/10.1080/00498254.2024.2403029
  18. Curr Protoc. 2024 Sep;4(9): e70009
      LipidOne 2.0 (https://lipidone.eu) is a new web bioinformatic tool for the analysis of lipidomic data. It facilitates the exploration of the three structural levels of lipids: classes, molecular species, and lipid building blocks (acyl, alkyl, or alkenes chains). The tool's flexibility empowers users to seamlessly include or exclude experimental groups and lipid classes at any stage of the analysis. LipidOne 2.0 offers a range of mono- and multivariate statistical analyses, specifically tailored to each structural level. This includes a novel lipid biomarker identification function, integrating four diverse statistical parameters. LipidOne 2.0 incorporates Lipid Pathway analysis across all three structural levels of lipids. Users can identify lipid-involved reactions through case-control comparisons, generating lists of genes/enzymes and their activation states based on Z scores. Accessible without the need for registration, LipidOne 2.0 provides a user-friendly and efficient platform for exploring and analyzing lipidomic data. © 2024 The Author(s). Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Dataset preparation for LipidOne 2.0 Support Protocol: Lipid nomenclature from spectrometric experiments Basic Protocol 2: Uploading a dataset into LipidOne 2.0 Basic Protocol 3: Data mining of lipidomic dataset by LipidOne 2.0.
    Keywords:  R Core Team (2024); data mining; lipid pathway; lipidomics; system biology
    DOI:  https://doi.org/10.1002/cpz1.70009
  19. Front Oncol. 2024 ;14 1464240
      
    Keywords:  cancer; cancer therapy; clinical implications; lipid metabolism; tumor metabolic microenvironment
    DOI:  https://doi.org/10.3389/fonc.2024.1464240
  20. Mass Spectrom Rev. 2024 Sep 19.
      The exploration of protein structure and function stands at the forefront of life science and represents an ever-expanding focus in the development of proteomics. As mass spectrometry (MS) offers readout of protein conformational changes at both the protein and peptide levels, MS-based structural proteomics is making significant strides in the realms of structural and molecular biology, complementing traditional structural biology techniques. This review focuses on two powerful MS-based techniques for peptide-level readout, namely limited proteolysis-mass spectrometry (LiP-MS) and cross-linking mass spectrometry (XL-MS). First, we discuss the principles, features, and different workflows of these two methods. Subsequently, we delve into the bioinformatics strategies and software tools used for interpreting data associated with these protein conformation readouts and how the data can be integrated with other computational tools. Furthermore, we provide a comprehensive summary of the noteworthy applications of LiP-MS and XL-MS in diverse areas including neurodegenerative diseases, interactome studies, membrane proteins, and artificial intelligence-based structural analysis. Finally, we discuss the factors that modulate protein conformational changes. We also highlight the remaining challenges in understanding the intricacies of protein conformational changes by LiP-MS and XL-MS technologies.
    Keywords:  cross‐linking; interactome; limited proteolysis; mass spectrometry; neurodegenerative diseases; structural proteomics
    DOI:  https://doi.org/10.1002/mas.21908
  21. Cold Spring Harb Perspect Med. 2024 Sep 16. pii: a041555. [Epub ahead of print]
      Fueled by technological and conceptual advancements over the past two decades, research in cancer metabolism has begun to answer questions dating back to the time of Otto Warburg. But, as with most fields, new discoveries lead to new questions. This review outlines the emerging challenges that we predict will drive the next few decades of cancer metabolism research. These include developing a more realistic understanding of how metabolic activities are compartmentalized within cells, tissues, and organs; how metabolic preferences in tumors evolve during cancer progression from nascent, premalignant lesions to advanced, metastatic disease; and, most importantly, how we can best translate basic observations from preclinical models into novel therapies that benefit patients with cancer. With modern tools and an incredible amount of talent focusing on these problems, the upcoming decades should bring transformative discoveries.
    DOI:  https://doi.org/10.1101/cshperspect.a041555
  22. Anal Chem. 2024 Sep 15.
      Highly unsaturated fatty acids (HUFAs) are vulnerable to oxygen attack, thus making HUFA-rich, high metabolic rate/reactive oxygen species (ROS)-generating neurological tissue particularly susceptible to increased oxidative stress. Lipid oxidation is a putative early stage marker of neurodegenerative diseases, suggesting that reliable monitoring of oxidized neural lipids in vivo reveals early pathogenesis. Here, we present a novel methodology to detect and quantify intactin vivo ROS-driven peroxidized phospholipids (LPOx-PLs) in bovine retina extract. A protocol for preparing autoxidized pure phospholipids (PLs) and complex retinal extracts served as reference standards and was adapted to enable analytical parameter development. Fatty acid profiles of bovine retinas were first established with routine gas chromatography (GC) methods and used to customize mass spectrometry scanning for major HUFA-carrying PLs in the retinal extract. Targeted multiple reaction monitoring (MRM) scanning via triple quadrupole tandem mass spectrometry detected native (unoxidized) and oxidation-damaged PL regardless of the position of the O or O2 addition along the acyl chains and enabled quantification of relative signals from intact native and oxidized PL (5%-10% CV). MRM-triggered information-dependent acquisition (IDA) spectra confirmed the structure of peroxidized PLs, revealing that peroxidized species (+O-OH) dominated over single O-added species in vitro and in vivo. Positive identification and relative quantification are reported for 12 selected in vivo native and peroxidized phosphatidylcholines and phosphatidylethanolamines. These results enable future studies of the initial peroxidation due to toxins, genetics, or other initiating events influencing in vivo oxidation levels and potentially the effectiveness of strategies to mitigate this mechanism of action.
    DOI:  https://doi.org/10.1021/acs.analchem.4c03289
  23. J Chromatogr B Analyt Technol Biomed Life Sci. 2024 Sep 07. pii: S1570-0232(24)00308-8. [Epub ahead of print]1247 124299
      Fermentation-derived short-chain fatty acids (SCFA)4 are potential mediators of the health benefits associated with dietary fiber intake. SCFA affect physiological processes locally in the gut and on distant organs via the systemic circulation. Since SCFA are used as energy source for colonocytes and substrate for the liver metabolism, their concentrations in the systemic circulation are low. Therefore, quantification of systemic SCFA requires sensitive analytical techniques. This article covers the optimization and validation of a gas chromatography-mass spectrometry method to measure systemic SCFA concentrations following derivatization with 2,4-difluoroaniline (DFA)5 and extraction in ethyl acetate. Sample preparation was optimized by varying the amount of DFA, coupling agent 1,3-dicyclohexylcarbodiimide, ethyl acetate and sodium bicarbonate, which is used to quench derivatization. In addition, evaporation of the samples using a vacuum concentrator resulted in less contamination, notably of acetate, compared to drying with N2 gas. The method showed excellent linearity with coefficient of variation (R2) > 0.99 and a good precision (relative standard deviation < 20 %) and accuracy. Finally, systemic concentrations of SCFA in human plasma samples could successfully be determined.
    Keywords:  2,4-difluoroaniline; Blood; Derivatization; Systemic circulation; gas chromatography-mass spectrometry (GC–MS); short-chain fatty acids (SCFA)
    DOI:  https://doi.org/10.1016/j.jchromb.2024.124299