The search for novel and clinically relevant biomarkers still represents a major clinical challenge and mass-spectrometry-based technologies are essential tools to help in this process. In this application, we demonstrate how selected reaction monitoring (SRM) can be applied in a highly multiplexed way to analyze formalin-fixed paraffin-embedded (FFPE) tissues. Such an assay can be used to analyze numerous samples for narrowing down a list of potential biomarkers to the most relevant candidates. The use of FFPE tissues is of high relevance in this context as large sample collections linked with valuable clinical information are available in hospitals around the world. Here we describe in detail how we proceeded to develop such an assay for 200 proteins in breast tumor FFPE tissues. We cover the selection of suitable peptides, which are different in FFPE compared to fresh frozen tissues and show how we deliberately biased our assay toward proteins with a high probability of being measurable in human clinical samples.
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http://dx.doi.org/10.1007/978-1-4939-9164-8_13 | DOI Listing |
J Pathol
January 2025
The Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia.
Spatial transcriptomics (ST) offers enormous potential to decipher the biological and pathological heterogeneity in precious archival cancer tissues. Traditionally, these tissues have rarely been used and only examined at a low throughput, most commonly by histopathological staining. ST adds thousands of times as many molecular features to histopathological images, but critical technical issues and limitations require more assessment of how ST performs on fixed archival tissues.
View Article and Find Full Text PDFJ Histochem Cytochem
January 2025
Program in Translational Medicine, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
Formalin-fixed paraffin-embedded tissue (FFPET), which is the most widely used pathology archive, usually has low-quality DNA and RNA due to extensive nucleic acid crosslinking. RNA fluorescence in situ hybridization (RNA-FISH) has been increasingly utilized in research and clinical settings to diagnose disease pathology. In this study, the effect of RNA degradation over archival time on RNA-FISH signals in FFPET and fresh frozen tissue (FFT) was systematically assessed.
View Article and Find Full Text PDFBiol Proced Online
January 2025
Department of Laboratory Medicine, West China Hospital of Sichuan University, Chengdu, 610041, China.
Archived clinical formalin-fixed paraffin-embedded tissue (FFPE) is valuable for the study of tumor epigenetics. Although protocol of chromatin immunoprecipitation coupled with next generation sequencing (NGS) (ChIP-seq) using FFPE samples has been established, removal of interference signals from non-target cell components in the samples is still needed. In this study, the protocol of ChIP-seq with purified cells from FFPE lymphoid tissue of nodal T follicular helper cell lymphoma, angioimmunoblastic type (nTFHL-AI) after fluorescence-activated cell sorting (FACS) was established and optimized.
View Article and Find Full Text PDFClin Epigenetics
January 2025
Department of Pathology, Clinical Oncology School of Fujian Medical University, Fujian Cancer Hospital, Fuzhou, China.
Background: 5-Hydroxymethylcytosine (5hmC) modification represents a significant epigenetic modification within DNA, playing a pivotal role in a range of biological processes associated with various types of cancer. The role of 5hmC in systemic anaplastic large cell lymphoma (ALCL) has not been thoroughly investigated. This study aims to examine the function of 5hmC in the advancement of ALCL.
View Article and Find Full Text PDFToxicol Pathol
January 2025
Gilead Sciences, Foster City, California, USA.
Characterizing the expression of novel targets in normal and diseased tissues is a fundamental component of a target validation data package. Often these targets are presented to the pathology team for assessment with bulk or single-cell RNAseq data and limited to no spatial tissue expression data. hybridization to detect mRNA (RNAscope) is a valuable tool to (1) identify cells that may express the target protein and to corroborate protein expression during immunohistochemical (IHC) assay development or (2) to use as surrogate for single-cell expression IHC when antibodies are not available.
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