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DNA methylation and copy number variation (CNV) profiling are essential for diagnostic tumor classification. Current methods are complex and require considerable bioinformatics expertise, limiting clinical implementation. Mepylome (https://mepylome.readthedocs.io), an efficient open‐source Python‐based toolkit for microarray‐based DNA methylation and CNV analysis, resolves these challenges. It enables, through artificial intelligence, local tumor methylome comparison with customizable reference sets. Mepylome provides an intuitive graphical interface, supports supervised and unsupervised learning techniques, and processes various Illumina methylation array types. Users can examine their own data, add references from any source, perform analyses including dimension reduction, individual and multisample CNV plotting, and build supervised learning models to augment diagnostic classification. Tested on Ubuntu Linux and Windows with WSL, Mepylome runs on most modern hospital computers, including macOS. Performance is demonstrated on previously published datasets, including 363 salivary gland tumors, 1077 soft tissue tumor specimens, and a multisource collection of 1644 squamous cell carcinomas, reproducing classification accuracies and visualizations. The trained soft tissue classifier is validated on an independent in‐house set. Mepylome runs up to 65 times faster than comparable tools, enabling direct point‐of‐care application and substantially simplifying and accelerating DNA methylation and CNV analysis in clinical settings. DNA methylation and chromosomal copy number profiling have recently become essential for tumor diagnostics. The open‐source tool Mepylome enables this task in clinical routine. It combines several machine learning strategies and allows users to interactively examine respective data through an intuitive graphical interface. Running up to 65 times faster than comparable tools Mepylome is well suited for office PCs.

DNA methylation analysis based on supervised machine learning algorithms with static reference data, allowing diagnostic tumour typing with unprecedented precision, has quickly become a new standard of care. Whereas genome-wide diagnostic methylation profiling is mostly performed on microarrays, an increasing number of institutions additionally employ nanopore sequencing as a faster alternative. In addition, methylation-specific parallel sequencing can generate methylation and genomic copy number data. Given these diverse approaches to methylation profiling, to date, there is no single tool that allows (1) classification and interpretation of microarray, nanopore and parallel sequencing data, (2) direct control of nanopore sequencers, and (3) the integration of microarray-based methylation reference data. Furthermore, no software capable of entirely running in routine diagnostic laboratory environments lacking high-performance computing and network infrastructure exists. To overcome these shortcomings, we present EpiDiP/NanoDiP as an open-source DNA methylation and copy number profiling suite, which has been benchmarked against an established supervised machine learning approach using in-house routine diagnostics data obtained between 2019 and 2021. Running locally on portable, cost- and energy-saving system-on-chip as well as gpGPU-augmented edge computing devices, NanoDiP works in offline mode, ensuring data privacy. It does not require the rigid training data annotation of supervised approaches. Furthermore, NanoDiP is the core of our public, free-of-charge EpiDiP web service which enables comparative methylation data analysis against an extensive reference data collection. We envision this versatile platform as a useful resource not only for neuropathologists and surgical pathologists but also for the tumour epigenetics research community. In daily diagnostic routine, analysis of native, unfixed biopsies by NanoDiP delivers molecular tumour classification in an intraoperative time frame.

Hadi Al-Hasani and colleagues report that a frameshift deletion in Tbc1d1 in lean SJL mice underlies a quantitative trait locus conferring protection against high-fat diet-induced obesity. TBC1D1 seems to influence metabolism by regulating fatty acid uptake and oxidation in skeletal muscle cells. We previously identified Nob1 as a quantitative trait locus for high-fat diet–induced obesity and diabetes in genome-wide scans of outcross populations of obese and lean mouse strains. Additional crossbreeding experiments indicated that Nob1 represents an obesity suppressor from the lean Swiss Jim Lambert (SJL) strain. Here we identify a SJL-specific mutation in the Tbc1d1 gene that results in a truncated protein lacking the TBC Rab–GTPase-activating protein domain. TBC1D1, which has been recently linked to human obesity, is related to the insulin signaling protein AS160 and is predominantly expressed in skeletal muscle. Knockdown of TBC1D1 in skeletal muscle cells increased fatty acid uptake and oxidation, whereas overexpression of TBC1D1 had the opposite effect. Recombinant congenic mice lacking TBC1D1 showed reduced body weight, decreased respiratory quotient, increased fatty acid oxidation and reduced glucose uptake in isolated skeletal muscle. Our data strongly suggest that mutation of Tbc1d1 suppresses high-fat diet–induced obesity by increasing lipid use in skeletal muscle.

Molecular data integration plays a central role in central nervous system (CNS) tumor diagnostics but currently used assays pose limitations due to technical complexity, equipment and reagent costs, as well as lengthy turnaround times. We previously reported the development of Rapid-CNS 2 , an adaptive-sampling-based nanopore sequencing workflow. Here we comprehensively validated and further developed Rapid-CNS 2 for intraoperative use. It now offers real-time methylation classification and DNA copy number information within a 30-min intraoperative window, followed by comprehensive molecular profiling within 24 h, covering the complete spectrum of diagnostically and therapeutically relevant information for the respective entity. We validated Rapid-CNS 2 in a multicenter setting on 301 archival and prospective samples including 18 samples sequenced intraoperatively. To broaden the utility of methylation-based CNS tumor classification, we developed MNP-Flex, a platform-agnostic methylation classifier encompassing 184 classes. MNP-Flex achieved 99.6% accuracy for methylation families and 99.2% accuracy for methylation classes with clinically applicable thresholds across a global validation cohort of more than 78,000 frozen and formalin-fixed paraffin-embedded samples spanning five different technologies. Integration of these tools has the potential to advance CNS tumor diagnostics by providing broad access to rapid, actionable molecular insights crucial for personalized treatment strategies. Application of a nanopore sequencing workflow for real-time analysis of brain tumors results in molecular classification within a 30-minute intraoperative window, followed by comprehensive profiling within 24 hours.

Outside In Acquisition and analysis of large data sets promises to move us toward a greater understanding of the mechanisms by which biological systems are dynamically regulated to respond to external cues. Now, two papers explore the responses of a bacterium to changing nutritional conditions (see the Perspective by Chalancon et al. ). Nicolas et al. (p. 1103 ) measured transcriptional regulation for more than 100 different conditions. Greater amounts of antisense RNA were generated than expected and appeared to be produced by alternative RNA polymerase targeting subunits called sigma factors. One transition, from malate to glucose as the primary nutrient, was studied in more detail by Buescher et al. (p. 1099 ) who monitored RNA abundance, promoter activity in live cells, protein abundance, and absolute concentrations of intracellular and extracellular metabolites. In this case, the bacteria responded rapidly and largely without transcriptional changes to life on malate, but only slowly adapted to use glucose, a shift that required changes in nearly half the transcription network. These data offer an initial understanding of why certain regulatory strategies may be favored during evolution of dynamic control systems.

Autism and mental retardation (MR) are often associated, suggesting that these conditions are etiologically related. Recently, array‐based comparative genomic hybridization (array CGH) has identified submicroscopic deletions and duplications as a common cause of MR, prompting us to search for such genomic imbalances in autism. Here we describe a 1.5‐Mb duplication on chromosome 16p13.1 that was found by high‐resolution array CGH in four severe autistic male patients from three unrelated families. The same duplication was identified in several variably affected and unaffected relatives. A deletion of the same interval was detected in three unrelated patients with MR and other clinical abnormalities. In one patient we revealed a further rearrangement of the 16p13 imbalance that was not present in his unaffected mother. Duplications and deletions of this 1.5‐Mb interval have not been described as copy number variants in the Database of Genomic Variants and have not been identified in >600 individuals from other cohorts examined by high‐resolution array CGH in our laboratory. Thus we conclude that these aberrations represent recurrent genomic imbalances which predispose to autism and/or MR. Hum Mutat 28(7), 674–682, 2007. © 2007 Wiley‐Liss, Inc.

The flavoprotein 2-aminobenzoyl-CoA monooxygenase/reductase from the eubacterium Azoarcus evansii catalyzes the dearomatization of 2-aminobenzoyl-CoA. The reaction consists in an O2-dependent monooxygenation at the benzene position 5, which is followed immediately by an NADH-dependent hydrogenation of the intermediate at the same catalytic locus. The reaction was studied by 1H,2H, and 13C NMR spectroscopy of the products. The main product was characterized as 5-oxo-2-aminocyclohex-1-ene-1-carboxyl-CoA by two-dimensional NMR spectroscopy. Thus [5-2H]2-aminobenzoyl-CoA was converted into $\\text{[6-}^{2}\\text{H]5-oxo-2-aminocyclohex-1-ene-1-carboxyl-CoA}$< /latex>, indicating a 5→ 6 shift of the [5-2H] label. Label from NAD2H was transferred to the 3 position of the cyclic eneamine, whereas label from solvent D2O was incorporated into the 4 and the 6 positions of 5-oxo-2-aminocyclohex-1-ene-1-carboxyl-CoA. The labeling pattern is compatible with the monooxygenation proceeding via what is formally an NIH shift, yielding 5-oxo-2-aminocyclohex-1,3-diene-1-carboxyl-CoA as a protein-bound intermediate. It is suggested that this shift in flavin-dependent monooxygenation may have general validity.

Citrate synthase (CS) is often used in chaperone assays since this thermosensitive enzyme aggregates at moderately increased temperatures. Small heat shock proteins (sHsps) are molecular chaperones specialized in preventing the aggregation of other proteins, termed substrate proteins, under conditions of transient heat stress. To investigate the mechanism whereby sHsps bind to and stabilize a substrate protein, we here used peptide array screening covering the sequence of porcine CS (P00889). Strong binding of sHsps was detected to a peptide corresponding to the most N-terminal α-helix in CS (amino acids Leu₁₃ to Gln₂₇). The N-terminal α-helices in the CS dimer intertwine with the C-terminus in the other subunit and together form a stem-like structure which is protruding from the CS dimer. This stem-like structure is absent in thermostable forms of CS from thermophilic archaebacteria like Pyrococcus furiosus and Sulfolobus solfatacarium. These data therefore suggest that thermostabilization of thermosensitive CS by sHsps is achieved by stabilization of the C- and N-terminae in the protruding thermosensitive softspot, which is absent in thermostable forms of the CS dimer.

Chemically synthesized peptide arrays on planar cellulose carriers are proposed as libraries of ligands suitable for the multiplexed simultaneous capture of peptide-specific acceptor proteins from a large randomly mutagenized library of acceptor proteins presented on bacteriophage M13 particles. This experimental set-up can be exploited to rapidly screen for individual new, distinct binding partners from two complementary libraries (two-dimensional screening). The technical feasibility of this empirical protein design approach was demonstrated with calmodulin as an aceptor protein using an array of mastoparan variants for multiplexed phage affinity enrichment.

Copyright © 2006 S. Karger AG, Basel