Biology subjects

Kriegsheim, A. v.

Publications and source records attributed to Kriegsheim, A. v..

3 recordsLinked to original sources

bioRxiv2026

Enhancing Lipid Detection and Spatial Accuracy in Carotid Plaques Using Mass Spectrometry Imaging Techniques

Matrix-assisted laser desorption/ionisation mass spectrometry imaging (MALDI-MSI) is a powerful technique for studying lipid distribution in carotid plaques, key to understanding atherosclerosis. This study aimed to improve sample preparation for MALDI-MSI-based spatial lipidomics of carotid plaques by improving both matrix application and tissue handling. Human carotid plaques were collected from endarterectomy patients with ethical approval and sectioned at 10 {micro}m thickness for MALDI-MSI. We compared eight sample preparation methods, including hydroxypropyl methylcellulose-polyvinylpyrrolidone (HPMC-PVP) embedding media and Cryofilm-type IMS(R) to provide support and maintain tissue structural integrity during sectioning. Methods were assessed for signal intensity, lipid diffusion, lipid coverage, tissue morphology, and image co-registration which each criterion scored from 1-3. Cryofilm-based methods scored highest for preserving tissue morphology and minimising folding artifacts (2.9-3.0) but were limited in co-registration (2.0) due to reliance on adjacent sections. Sublimation methods generally produced greater lipid coverage with reduced lateral diffusion, while automated sprayer methods scored higher in signal intensity/sensitivity (3.0) but had increased lipid delocalisation, particularly for highly hydrophobic species such as triacylglycerols and sterols. The results highlight clear trade-offs between tissue structural preservation, lipid detection sensitivity, and spatial integrity in MALDI-MSI. Because spatial integrity cannot be compromised for imaging lipids in carotid atherosclerotic plaques, Cryofilm combined with sublimation offers a clear advantage. This work strengthens MALDI-MSI workflows enabling more precise spatial mapping and deeper biological interpretation of atherosclerotic lipid distributions.

molecular biology↗

bioRxiv2025

USP18 Inhibition Enhances Type I Interferon Signalling and Immune Activation in the Tumour Microenvironment of Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is one of the most aggressive and treatment-resistant breast cancers. Although immunotherapy has emerged as a promising treatment option, clinical benefit is limited, with only around half of patients responding, even when combined with standard chemotherapeutic agents. This limited efficacy is often attributed to immunologically "cold" tumour microenvironments (TME), which are resistant to current immunotherapies. Addressing this challenge requires approaches that can reprogram "cold" TMEs into "hot" immune-responsive states. USP18, a negative regulator of type I interferon (IFN) signalling, suppresses immune activation by removing ISG15 from target proteins and disrupting IFNAR-STAT2 interactions. Here, we show that both genetic ablation and catalytic inactivation of USP18 enhance type I IFN signalling in TNBC cells, leading to sustained STAT1/STAT2 phosphorylation. This increased IFN responsiveness promotes antigen presentation via MHC-I upregulation and increases expression of pro-apoptotic ligands such as FAS. Proteomic profiling and immunophenotyping revealed that USP18 inhibition in vivo reduces tumour growth and increases immunogenicity, accompanied by cancer-immune infiltration modulation including CD8 T cells, Th1 cells, NK cells, cDC1, and pro-inflammatory M1-like macrophages. These changes reflect a shift in the TME from an immunosuppressive to an immunostimulatory state, driven by heightened and prolonged type I IFN signalling. Our findings highlight the therapeutic potential of USP18 inhibition to convert immunologically "cold" tumours into "hot" tumours, by enhancing IFN-driven immune activation and improving the efficacy of immunotherapy in TNBCs.

cancer biology↗

bioRxiv2025

Tumour genotype shapes blood biomarker expression for use in pancreatic cancer detection and diagnosis.

Typically diagnosed late, when systemic metastasis has already occurred, pancreatic ductal adenocarcinoma (PDAC) has one of the worst 5-year survival rates of any cancer type. For many patients with advanced disease, current chemotherapy regimens offer only modest benefit despite significant toxicity and surgical resection, the only treatment option with curative potential, is not possible. Therefore, while new treatments are much needed, diagnosing patients at an earlier disease stage when surgery remains possible and the window of opportunity for treatment response is longer will be critical to improving patient outcomes. In this regard, the identification of biomarkers from biospecimens that can be easily sampled from patients remains the focus of considerable research, however success has not been forthcoming. Using a suite of novel genetically defined murine isogenic models of early PDAC, engineered using CRISPR-Cas9 gene editing, we sought to address whether loss-of-function mutations in common driver genes, and thus the genetic heterogeneity inherent to the disease, may represent an important confounding factor in the identification of a one-size-fits-all biomarker suitable for early detection. Focussing on the multi-omics analysis of blood, we show that both loss of Cdkn2a and / or Smad4 on the background of a KrasG12D Trp53-/- genotype has profound effects on the profile of differentially expressed RNA species including protein coding RNAs, lncRNAs, snoRNAs, scRNAs, snRNAs and miRNAs, and on plasma protein expression, when compared to both healthy controls and chemically induced pancreatitis. In addition, we find that loss of Smad4, a genomic event that occurs following progression from PanIN to PDAC, substantially limits the availability of blood biomarkers. These findings identify the need to move towards genotype-specific biomarker signatures and uncover a potential role for Smad4 loss in limiting opportunities for the early detection of pancreatic cancer.

cancer biology↗