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Extraction, Purification, and Next-Generation Sequencing (NGS) Analysis of DNA and RNA from Formalin-Fixed and Paraffin-Embedded (FFPE) Tissue.

Formalin fixed paraffin embedded (FFPE) tissues have long been used for immunohistological analyses. FFPE tissues can be stored at room temperature for several years enabling analyses to be performed later. Ease of storage and transport makes these tissues an attractive source of biological material. However, formalin fixation results in chemical modifications of proteins and nucleic acids that poses a major challenge to any type of analysis. Recovery of nucleic acids for quantitative assays is rendered difficult due to degradation resulting from fixation and long-term storage, producing low usable yields. Extensive efforts in the last 20 years have led to significant improvements in use of FFPE tissues for DNA and RNA analyses and resulted in development of sensitive assays for a wide range of applications, including next-generation sequencing. In this chapter, we describe the optimization of methods for sequential extraction of DNA and RNA from FFPE tissue and subsequent preparation of DNA-seq and RNA-seq libraries for use with the Illumina platform using commercially available reagents/kits.

Paraffin Embedding

Systematic comparison of quantity and quality of RNA recovered with commercial FFPE tissue extraction kits.

BACKGROUND: FFPE tissue samples are commonly used in biomedical research and are a valuable source for next-generation sequencing in oncology, however, extracting RNA from these samples can be difficult the quantity and quality achieved can impact the downstream analysis. This study compared the effectiveness of seven different commercially available RNA extraction kits specifically designed for use with FFPE samples in terms of the quantity and quality of RNA recovered. METHODS: This study used 9 samples of FFPE tissue from three different types of tissue (Tonsil, Appendix and lymph node of B-cell lymphoma) to evaluate RNA extraction methods. Three sections of 20 µm of each sample were combined per sample. The slices were distributed in a systematic manner to prevent any biases. Each of the 7 commercially available RNA extraction kits were used according to manufacturer's instructions, with each sample being tested in triplicate resulting in a total of 189 extractions. The concentration, RNA quality score (RQS) and DV200 of each extraction was analysed using a nucleic acid analyser to determine the quantity and quality of the recovered RNA. RESULTS: This study found that despite processing the FFPE samples in the same standardized way, there were disparities in the quantity and quality of RNA recovered across the different tissue types. Additionally, the study found notable differences in the quantity of RNA recovered when using different extraction kits. In terms of quality, three of the kits performed better than the other four in terms of RQS and DV200 values. CONCLUSION: Though many laboratories have developed their own protocols for specific tissue types, using commercially available kits is still a popular option. Although these kits use similar processes and extraction procedures, the amount and quality of RNA obtained can vary greatly between kits. In this study, among the kits tested, while the Roche kit, provided a nearly systematic better-quality recovery than other kits, the ReliaPrep FFPE Total RNA miniprep from Promega yielded the best ratio of both quantity and quality on the tested tissue samples.

Paraffin Embedding

Novel antibodies for identification, selection, and manipulation of T cells expressing Whitlow linker-containing CARs.

BACKGROUND: The translational study of chimeric antigen receptor (CAR) T-cell function, persistence, immunophenotype, and spatial localization after infusion is crucial for understanding factors that influence clinical outcomes. However, research has been limited by a lack of optimized tools to reliably detect CAR-engineered cells. To address this, we developed a novel platform to generate monoclonal antibodies (mAbs) targeting a linker peptide incorporated in single-chain variable fragments (scFvs) of most CAR constructs. METHODS: Using recombinant proteins and scFv linker peptides as immunogens, we generated murine mAbs against the Whitlow linker peptide, capable of binding cells expressing Whitlow linker-containing CARs in both fresh and formalin-fixed paraffin-embedded (FFPE) tissues. We evaluated these antibodies in multiple in vitro translational applications relevant to CAR T-cell research and manufacturing. RESULTS: We identified five unique mAbs reactive against the Whitlow linker and characterized their binding properties and three-dimensional structural conformation. One clone was evaluated in depth, demonstrating comparable capacity to identify CAR T cells in peripheral blood relative to other methods using anti-idiotype antibodies or recombinant CAR-target proteins. In contrast to these reagents, the anti-Whitlow mAb detects cells expressing Whitlow linker-containing CARs with different antigen specificities, including those harboring the widely employed anti-CD19 FMC63-derived scFv as well as other scFvs, such as those targeting B-cell maturation antigen (BCMA) or CD33. Importantly, the anti-Whitlow mAb identified CAR T cells in situ in archival FFPE tissues, and a DNA-barcoded format enabled their spatial characterization and immunophenotyping in highly multiplexed immunohistochemistry. We also assessed the functional consequences of antibody binding on CAR T cells in vitro and demonstrated the feasibility of anti-Whitlow mAb-mediated selective enrichment of CAR-expressing T cells for potential utility in manufacturing workflows. CONCLUSIONS: Anti-Whitlow mAb clones exhibited distinct structural and functional properties that can be leveraged for multiple applications, providing versatile tools for detection, selection and manipulation of a broad range of clinical and preclinical CAR T-cell products.

Humans

Spatial Total RNA Sequencing of Formalin-Fixed Paraffin-Embedded Tissue by spRandom-seq.

The molecular pathogenesis of infectious diseases and cancer is orchestrated by nanoscale of host and microbial RNA transcripts within the tissue microenvironment. Nevertheless, spatially resolving the comprehensive transcriptional landscape within complex clinical tissues, like formalin-fixed paraffin-embedded (FFPE) specimens, still poses a formidable challenge. Here, we present spRandom-seq, a random primer-based spatial total RNA sequencing technology designed to spatially resolve complete transcriptomes from host, bacteria, and even nanoscale viruses in FFPE tissues. Capitalizing on the random primer design, our technology not only facilitated the discovery of specific lncRNAs and alternative splicing events in mouse brain and olfactory bulb, but also delineated pronounced spatial heterogeneity in clinical FFPE sections-across distinct tumor regions in breast cancer and microbial infection sites in Klebsiella pneumoniae-infected tissues. Importantly, integrated analysis of host and viral RNAs in FFPE samples from hepatitis B virus (HBV)‑positive hepatocellular carcinoma (HCC) demonstrated that complement and coagulation pathways were specifically activated across expansive HBV‑infected tumor areas, which also exhibited an increased burden of copy number variations (CNVs). Owing to its compatibility with existing spatial transcriptomics platforms and minimal operational complexity, spRandom-seq represents a practical and scalable approach for clinical pathology applications and infection diagnostics.

Paraffin Embedding

Determinants of nucleic acid quality in formalin-fixed paraffin-embedded bladder urothelial carcinoma specimens: effects of specimen type, fixation conditions, and storage time.

Formalin-fixed paraffin-embedded (FFPE) tissue is the principal substrate for cancer genomic profiling, yet pre-analytical factors affect nucleic acid quality. In our workflow, transurethral resection (TUR) specimens of bladder urothelial carcinoma are fixed promptly but exposed to electrocautery, whereas robot-assisted radical cystectomy specimens are refrigerated overnight before fixation; we compared nucleic acid quality between these specimen types. We analyzed 56 FFPE primary bladder urothelial carcinoma specimens (33 TUR, 23 cystectomy). DNA quality was assessed by the DNA Integrity Number (DIN) and short-to-long cycle threshold ratio (S/L Ct ratio), and RNA quality by the RNA Integrity Number (RIN) and percentage of RNA fragments &#x2265;200 nucleotides (DV200), with group comparisons, Spearman correlations, and multivariable regression (specimen type, fixation duration, storage time). The median DIN (4.4 vs. 3.8, p&#xa0;=&#xa0;0.004) and S/L Ct ratio (0.943 vs. 0.894, p&#xa0;<&#xa0;0.001) were higher in TUR than cystectomy specimens; the RIN was also higher (1.9 vs. 1.7, p&#xa0;=&#xa0;0.040), though low in both groups, and DV200 did not differ (50.3% vs. 47.7%, p&#xa0;=&#xa0;0.934). In multivariable analysis, TUR specimen type independently predicted higher DIN (&#x3b2;&#xa0;=&#xa0;+0.460, p&#xa0;=&#xa0;0.040) and S/L Ct ratio (&#x3b2;&#xa0;=&#xa0;+0.442, p&#xa0;=&#xa0;0.009), whereas longer storage time independently decreased the S/L Ct ratio (&#x3b2;&#xa0;=&#xa0;-0.513, p&#xa0;<&#xa0;0.001) and RIN (&#x3b2;&#xa0;=&#xa0;-0.352, p&#xa0;=&#xa0;0.010). In our institutional workflow, TUR specimens showed higher DNA quality metrics than robot-assisted radical cystectomy specimens subjected to overnight refrigerated pre-fixation delay, whereas this workflow-associated advantage did not clearly extend to DV200-defined RNA fragment-length quality. Storage time was associated with selected aspects of nucleic acid deterioration.

Humans

Integration of Imaging-based and Sequencing-based Spatial Omics Mapping on the Same Tissue Section via DBiTplus.

Spatially mapping the transcriptome and proteome in the same tissue section can significantly advance our understanding of heterogeneous cellular processes and connect cell type to function. Here, we present Deterministic Barcoding in Tissue sequencing plus (DBiTplus), an integrative multi-modality spatial omics approach that combines sequencing-based spatial transcriptomics and image-based spatial protein profiling on the same tissue section to enable both single-cell resolution cell typing and genome-scale interrogation of biological pathways. DBiTplus begins with in situ reverse transcription for cDNA synthesis, microfluidic delivery of DNA oligos for spatial barcoding, retrieval of barcoded cDNA using RNaseH, an enzyme that selectively degrades RNA in an RNA-DNA hybrid, preserving the intact tissue section for high-plex protein imaging with CODEX. We developed computational pipelines to register data from two distinct modalities. Performing both DBiT-seq and CODEX on the same tissue slide enables accurate cell typing in each spatial transcriptome spot and subsequently image-guided decomposition to generate single-cell resolved spatial transcriptome atlases. DBiTplus was applied to mouse embryos with limited protein markers but still demonstrated excellent integration for single-cell transcriptome decomposition, to normal human lymph nodes with high-plex protein profiling to yield a single-cell spatial transcriptome map, and to human lymphoma FFPE tissue to explore the mechanisms of lymphomagenesis and progression. DBiTplusCODEX is a unified workflow including integrative experimental procedure and computational innovation for spatially resolved single-cell atlasing and exploration of biological pathways cell-by-cell at genome-scale.

Journal Article

Integration of Imaging-based and Sequencing-based Spatial Omics Mapping on the Same Tissue Section via DBiTplus.

Spatially mapping the transcriptome and proteome in the same tissue section can significantly advance our understanding of heterogeneous cellular processes and connect cell type to function. Here, we present Deterministic Barcoding in Tissue sequencing plus (DBiTplus), an integrative multi-modality spatial omics approach that combines sequencing-based spatial transcriptomics and image-based spatial protein profiling on the same tissue section to enable both single-cell resolution cell typing and genome-scale interrogation of biological pathways. DBiTplus begins with in situ reverse transcription for cDNA synthesis, microfluidic delivery of DNA oligos for spatial barcoding, retrieval of barcoded cDNA using RNaseH, an enzyme that selectively degrades RNA in an RNA-DNA hybrid, preserving the intact tissue section for high-plex protein imaging with CODEX. We developed computational pipelines to register data from two distinct modalities. Performing both DBiT-seq and CODEX on the same tissue slide enables accurate cell typing in each spatial transcriptome spot and subsequently image-guided decomposition to generate single-cell resolved spatial transcriptome atlases. DBiTplus was applied to mouse embryos with limited protein markers but still demonstrated excellent integration for single-cell transcriptome decomposition, to normal human lymph nodes with high-plex protein profiling to yield a single-cell spatial transcriptome map, and to human lymphoma FFPE tissue to explore the mechanisms of lymphomagenesis and progression. DBiTplusCODEX is a unified workflow including integrative experimental procedure and computational innovation for spatially resolved single-cell atlasing and exploration of biological pathways cell-by-cell at genome-scale.

Journal Article

An Instrumental Optimization of a Label-Free Proteomic Method for Trace Protein Input.

Liquid chromatography-mass spectrometry (LC-MS)-based proteomics of trace-level samples, such as tens of cells or spatially resolved tissue regions, offers unique biological insights but is often constrained by the requirement for specialized, costly instrumentation. In this study, we developed a scalable workflow for the deep proteomic analysis of low- to ultralow-input samples by systematically optimizing a widely adopted Orbitrap and UHPLC platform to maximize sensitivity, precision, and throughput. This optimized workflow identified over 5600 proteins from 5 ng of peptides and 3400 proteins from 20 sorted cells, achieving a throughput of 30 analyses per day while maintaining deep proteome coverage and high quantitative reproducibility. Furthermore, by applying this method to spatially resolved proteomics, we identified over 6100 proteins from microscale regions of interest (ROIs) within a formalin-fixed, paraffin-embedded (FFPE) tissue. A data-driven normalization strategy was employed to correct for variable cellularity across tissue regions, effectively revealing intratumor heterogeneity and distinct molecular and functional signatures, including pathway activations not apparent in parallel spatial transcriptomic analysis. Ultimately, this accessible, high-performance method substantially lowers the instrumentation barrier for the deep proteomic profiling of trace-level biological samples.

Proteomics

[State Changes and Stability Grading of Driver Genes in Non-small Cell Lung Cancer Based on Repeated NGS Testing].

BACKGROUND: Next-generation sequencing (NGS)-based driver gene testing has become a routine component of molecular subtyping and precision therapy for non-small cell lung cancer (NSCLC). Dynamic genomic monitoring facilitates early detection of resistance-related molecular alterations and informs timely therapeutic adjustments. However, standardized criteria for evaluating the stability of serial NGS testing are currently lacking, and the applicability of NGS using formalin-fixed paraffin-embedded (FFPE) specimens for dynamic monitoring remains poorly defined. This study aims to establish a stability grading system for driver gene status alterations based on repeated NGS testing, and to provide evidence-based support for clinical repeat biopsy strategies. METHODS: Data from 1232 patients with NSCLC who underwent two or more NGS tests on FFPE tissue specimens at Beijing Chest Hospital between June 2019 and April 2026 were collected retrospectively. Patients with an interval of &#x2265;4 months between the initial and last tests were included to ensure the representativeness of temporal analysis, resulting in a main analysis cohort of 942 patients. The Kappa consistency test was used to evaluate the state stability of nine core driver genes [epidermal growth factor receptor (EGFR), Kirsten rat sarcoma viral oncogene homolog (KRAS), anaplastic lymphoma kinase (ALK), ROS proto-oncogene 1, receptor tyrosine kinase (ROS1), mesenchymal&#x2011;epithelial transition factor (MET), rearranged during transfection (RET), v-raf murine sarcoma viral oncogene homolog B1 (BRAF), erb&#x2011;b2 receptor tyrosine kinase 2 (ERBB2), and phosphatidylinositol&#x2011;4,5&#x2011;bisphosphate 3&#x2011;kinase catalytic subunit alpha (PIK3CA)] and to construct a five&#x2011;level grading system. Paired variant allele frequency (VAF) differences were compared using the Wilcoxon signed&#x2011;rank test. Independent influencing factors for mutation accumulation were identified by binary Logistic regression. RESULTS: The state stability of the nine genes was classified into five levels: EGFR showed high stability (Kappa=0.838), ROS1/ALK/KRAS good stability, BRAF/PIK3CA/RET moderate stability, and ERBB2 low stability, and MET showed high instability. MET exhibited the highest rate of state change (9.3%) with a raw observed agreement of 90.7%. Its Kappa value (0.172) was influenced by the low prevalence (3.7%) compression effect and should therefore be interpreted alongside the observed agreement (90.7%) and the prevalence-adjusted and bias-adjusted Kappa (PABAK). The VAF of PIK3CA increased significantly (P=0.005). T790M positivity increased from 5.8% to 10.8%, and 30 new C797S mutations were detected at the last test (13 with T790M, 17 without). The overall rate of new driver gene variants in the main cohort was 18.0%. Binary Logistic regression showed that a lower number of initial mutated genes was the only independent predictor of new variants [odds ratio (OR)=0.399, P<0.001], while sex and detection interval showed no independent association. CONCLUSIONS: A five level stability grading system for state changes of driver genes in NSCLC based on repeated NGS testing has been established. MET showed the most frequent state changes, which should be interpreted in conjunction with the prevalence effect. The VAF increase of PIK3CA is an observational finding, and its clinical significance requires further prospective validation. A lower initial mutation burden may reflect tumor clonal complexity and was associated with a higher likelihood of subsequent acquisition of new variants. FFPE based NGS is applicable for repeated testing at clinical treatment decision nodes.

Humans

PIK3CA Polymorphisms in Cervical Cancer: Differential Impact of rs6443624 and rs141178472.

BACKGROUND: Cervical cancer remains a major cause of mortality in low- and middle-income settings. We assessed whether two PIK3CA single-nucleotide polymorphisms (SNPs) rs6443624 (A/C) and rs141178472 (C/T) are associated with disease risk, clinicopathological features, and survival. MATERIALS AND METHODS: In a prospective case control study at a tertiary center, 154 participants were enrolled (77 cases, 77 controls). Genomic DNA was isolated from FFPE cervical tumors (QIAamp DNA FFPE Tissue Kit) and genotyped using TaqMan allelic discrimination. Clinicopathological variables (FIGO stage, histology, grade, treatment, tumor-infiltrating lymphocytes [TILs]) were abstracted from records. Genotype distributions were compared by Pearson chi-square. Associations with clinicopathological features used chi-square/Fisher's exact as appropriate; ANOVA compared age across genotypes. Overall survival (OS) was estimated by Kaplan-Meier and compared with the log-rank test; mean OS with SE and 95% CI is reported. RESULTS: Cases were predominantly locally advanced at presentation and squamous histology; most were moderately differentiated. rs6443624 differed significantly between cases and controls (&#x3c7;&#xb2;=21.1, p<0.001), with CC over-represented in cases and CA less frequent. rs141178472 showed no significant case control difference (&#x3c7;&#xb2;=2.9, p=0.086). For OS, rs6443624 showed a significant genotype effect (log-rank &#x3c7;&#xb2;=23.45, p=0.001): AA had the poorest survival, CA the longest, CC intermediate. rs141178472 was not associated with OS (&#x3c7;&#xb2;=1.06, p=0.588). Genotype clinicopathological correlations for stage group, grade, TILs, and treatment were non-significant or inconsistent, with some comparisons limited by small sample sizes. CONCLUSION: The PIK3CA rs6443624 variant appears to influence both susceptibility and prognosis in cervical cancer, highlighting its potential as a biomarker for molecular risk stratification. Validation in larger, multi-center cohorts incorporating HPV/p16 assessment and extended follow-up is warranted to confirm its clinical relevance.

Humans

The Proteomic Landscape of CTNNB1 Mutated Low-Grade Early-Stage Endometrial Carcinomas.

Endometrial carcinoma is the most frequent gynecologic malignancy in western countries. In recent years, mutations in CTNNB1 have been associated with worse prognosis in low-risk carcinomas. However, there is a lack of understanding of the proteomic implications of CTNNB1 mutations in this type of tumor. In this study, we performed shotgun proteomics using Formalin-Fixed Paraffin-Embedded (FFPE) tissue samples of CTNNB1 mutated and wild-type low-risk endometrial carcinomas. A publicly available proteomic and transcriptomic database was used to validate results. Differential protein expression and Gene Set Enrichment Analysis revealed dysregulation of pathways associated with cell keratinization, immune response modulation, and intracellular calcium regulation. CTNNB1 mutated tumors showed immune dysregulation at multiple levels including cytokine secretion, cell adhesion, and lymphocyte activation. These results were supported by tissue multiplex immunofluorescence analysis, demonstrating reduced CD8 tumor-infiltrating lymphocytes and different immune spatial interaction patterns. Intracellular calcium dysfunction was associated with key transcript dysregulation. We found an increased expression of CAMK2A and ROR2, suggesting a potential role for non-canonical Wnt pathway activation in CTNNB1 mutated tumors.

Humans

Spatial transcriptomic analysis of mouse parathyroid gland cells expressing an activating variant of Gcm2.

Glial cells missing 2 (GCM2) is an essential transcription factor for the development of parathyroid glands. Germline GCM2 variants that repress or enhance transcriptional activity predispose a subset of patients to hypoparathyroidism or hyperparathyroidism, respectively. A recurrent germline heterozygous activating missense variant of GCM2, p.Y394S has been identified in some patients with primary hyperparathyroidism. A genetically engineered knock-in mouse model of this variant corresponding to p.Y392S in the mouse Gcm2 gene (Gcm2 +/Y392S) did not show obvious parathyroid tumors. However, in GCM2-binding site mediated luciferase reporter assays in HEK293 cells, the mouse and the human variant both exhibited enhanced transcriptional activity. Therefore, we assessed the effect of this variant on gene expression in vivo in parathyroid glands from Gcm2 +/Y392S and WT mice. Using the 10x Genomics Visium platform, spatially resolved transcriptomic analysis was performed on formalin-fixed and paraffin-embedded (FFPE) tracheal tissue sections of Gcm2 +/Y392S and WT mice to capture RNA from parathyroid glands together with other cell types in the tissue sections. Transcriptome sequence data analysis detected 8 different clusters in the tissue sections based on similarity of gene expression profiles. Cluster-1, which contained parathyroid gland cells expressing Pth and Gcm2, was further evaluated for transcripts that were differentially expressed more than 2-fold in Gcm2 +/Y392S compared to WT. Increased transcript level of Lgals3 (galectin-3) was seen in Gcm2 +/Y392S parathyroid gland cells which is among markers of parathyroid carcinoma. Galectin-3 protein was detected in available FFPE human parathyroid samples of patients with germline heterozygous activating GCM2 variants, p.Y394S (n&#x2009;=&#x2009;4/10) or p.L379Q (n&#x2009;=&#x2009;2/2). These results indicate a potential for growth and malignancy of parathyroid glands expressing GCM2 variants. The transcriptomic data of mouse parathyroid gland cells generated in this study can serve as a valuable resource for investigating genes and pathways in normal or abnormal parathyroid gland growth and physiology.

GCM2, gene

LCM-Enriched Proteomic Characterization of Antibody-Mediated Glomerular Damage and Complement Activation in Pre-Clinical Models.

Biologics, lipid nanoparticles, and other therapeutic modalities can result in adverse events, often detected as lesions during preclinical pathology assessments. Characterization of these lesions provides valuable information during drug development to contextualize mechanisms of injury and assess species translatability. Here, we investigated the utility of a laser capture microdissection (LCM)-enriched mass spectrometry proteomics approach to analyze two well-characterized preclinical models of regional (glomerular) injury: Passive Heyman Nephritis in rats and bovine gamma globulin-induced glomerular injury in nonhuman primates (NHPs). Using LCM-enriched proteomics, glomeruli were isolated from formalin-fixed paraffin-embedded kidney tissue in the rat model, enabling identification of 4,661 proteins and quantification of 3,410. Proteinuria measurements were compared with digital pathology metrics of glomerular morphology and proteomics results, with all modalities yielding concordant evidence of glomerular injury and proteomics confirming the role of complement activation. The same LCM- enriched proteomics workflow was applied to an NHP model of induced glomerular damage, identifying 4,623 proteins, quantifying 3,000, and confirming qualitative concordance with established features of complement-mediated glomerular injury. Together, these findings illustrate the applicability of LCM-enriched proteomics for region-specific characterization of antibody-mediated tissue injury and support its use as a hypothesis-generating platform in translational toxicologic pathology.

Animals

Transcriptomic profiling across stages of non-muscle-invasive bladder cancer identifies fibroblast activation protein-alpha as a stromal biomarker associated with progression.

BACKGROUND: T1 non-muscle-invasive bladder cancer (NMIBC) represents a biologically aggressive subgroup with substantial heterogeneity in recurrence and progression risk. Current clinicopathological risk stratification tools lack sufficient precision to identify patients at the highest risk of progression to muscle-invasive bladder cancer (MIBC). OBJECTIVE: To characterize transcriptomic differences between T1 and&#x2009;<&#x2009;T1 (Ta/Tis) NMIBC and to explore the association of fibroblast activation protein-&#x3b1; (FAP) gene expression with disease progression. METHODS: Transcriptomic profiling was performed on formalin-fixed paraffin-embedded (FFPE) tumor tissue from 66 patients with primary, treatment-na&#xef;ve NMIBC and 5 patients with T2 disease (included for exploratory comparisons). Analyses included differential gene expression, gene set enrichment analysis (GSEA), molecular subtyping, immune cell deconvolution, and evaluation of FAP expression in relation to recurrence and progression. External validation of FAP was conducted in three independent NMIBC cohorts. RESULTS: T1 tumors demonstrated a distinct transcriptomic profile compared with&#x2009;<&#x2009;T1 tumors, characterized by enrichment of cell cycle-related and metabolic pathways and a higher prevalence of aggressive molecular subtypes. Despite these molecular differences, no statistically significant differences in recurrence-free, progression-free, cancer-specific, and overall survival were observed, likely reflecting limited event numbers. Among recurrent tumors, early recurrences (&#x2264;&#x2009;24&#xa0;months) were associated with epithelial-mesenchymal transition signatures. FAP expression increased with tumor stage (p&#x2009;=&#x2009;0.0005) and was associated with progression (p&#x2009;=&#x2009;0.002) and mortality (p&#x2009;=&#x2009;0.01). Patients with tumors in the highest quartile of FAP expression had worse progression-free survival. This association was consistently observed in three external NMIBC cohorts. CONCLUSIONS: T1 NMIBC exhibits distinct transcriptomic features suggestive of increased biological aggressiveness. Elevated FAP expression is reproducibly associated with progression risk across multiple cohorts, supporting its potential role as a biomarker of aggressive disease. Given the limited number of progression events, these findings should be considered hypothesis-generating and warrant prospective validation before clinical implementation.

Humans

Association of HPV16 infection with p53 and&#xa0;survivin expression in oral squamous cell&#xa0;carcinoma.

Oral squamous cell carcinoma (OSCC) is the most common malignancy of the oral cavity and a major public health concern worldwide. This study aimed to investigate the relationship between p53 and survivin expression, clinicopathologic parameters and HPV16 infection in OSCC in order to elucidate the potential role of HPV16 in its pathogenesis.The study enrolled 45 patients who underwent surgical treatment for histologically confirmed OSCC. Tumor specimens were formalin-fixed and paraffin-embedded (FFPE) and histologically analyzed using hematoxylin/eosin staining. Immunohistochemistry for p53 and survivin was performed using the DAKO system. DNA extracted from FFPE tumor tissues was analyzed for HPV16 genome presence using polymerase chain reaction (PCR). All patients were followed for three years after primary treatment.No statistically significant associations were observed between p53 or survivin expression and clinicopathologic parameters including age, gender, tumor site, grade, stage, recurrence, metastasis or HPV16 status (P > 0.05). Among HPV16-positive patients (11/45, 24.4%), low survivin expression (<5%) was found in 8/11 (73%) patients, while high p53 expression (>10%) was observed in 7/11 (64%) patients. Disease-free interval did not differ significantly between patients with low vs. high p53&#xa0;(P&#xa0;=&#xa0;0.220) or survivin expression (P = 0.580). A significant correlation was detected between p53&#xa0;and survivin expression (P = 0.04). HPV16 positivity was significantly associated with the absence of p53&#xa0;immunoreactivity.These findings suggest that HPV16-independent oncogenic pathways are likely predominant in OSCC, while HPV16 infection may be associated with a distinct molecular subset characterized by absent p53 expression (p53-; survivin+/-; HPV16+). These results underscore the biological heterogeneity of OSCC and may have implications for future biomarker-based stratification of patients.

HPV16

Antibody-Based Proximity Labeling Reveals Bait-Proximal Proteomes in Paraffin-Embedded and Snap-Frozen Tissue Samples.

Proximity-based labeling approaches have proven highly valuable for uncovering protein-protein interactions, yet their application to primary patient material remains challenging. Here, we present a workflow enabling the use of the antibody-based ProtA-Turbo proximity labeling system in both formalin-fixed paraffin-embedded (FFPE) and snap-frozen tissue specimens. Our method efficiently directs biotinylation to diverse antibody baits across tissues of different origins. Downstream mass spectrometry-based proteomics analyses demonstrate the specificity of the method by profiling the proximal proteome of H3K27ac-marked chromatin, the nuclear lamina-associated protein EMD, and the Ser2-phosphorylated POLR2A subunit of RNA polymerase II. Using this method, we identified cell-type-specific factors and transcriptional regulators in salivary gland carcinoma, healthy testis, and testicular cancer tissue sections. The ability to detect disease-associated complexes directly within their native, spatially resolved cellular context using ProtA-Turbo can provide new insights into the molecular basis of human disease and may reveal novel, potentially actionable factors with translational relevance.

Humans

Diagnostic performance of panfungal PCR on tissue specimens for the diagnosis of invasive fungal diseases: a systematic review and meta-analysis of the Fungal PCR Initiative (FPCRI).

UNLABELLED: Invasive fungal diseases are difficult to diagnose because of the limited sensitivity of culture. Panfungal PCR amplicon sequencing assays (targeting ribosomal RNA, such as 18S, 28S, ITS) are recommended for fungal identification in histopathology samples showing fungal elements. However, data describing its overall performance and consistency are lacking. This systematic literature review and meta-analysis assessed the performance of panfungal PCR on formalin-fixed paraffin-embedded (FFPE) and non-fixed (fresh or frozen) tissue samples. A systematic literature search was performed to include studies reporting the use of panfungal PCR for fungal identification in FFPE or non-fixed tissue samples. PCR sensitivity and specificity were assessed using the reference standard of histopathology showing fungal elements. Quality assessment was performed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Pooled estimates were obtained using random-effects meta-analysis. Twenty-eight studies were included. In FFPE samples (18 studies, 852 samples), sensitivity and specificity were 75.4% (95% confidence interval [CI], 59.2-86.6) and 93.5% (70.2-98.9), respectively. Sensitivity in non-fixed samples (13 studies, 207 samples) was 86.5% (74.7-93.3), while specificity could not be assessed (insufficient data). Comparative analyses showed a significantly higher sensitivity of panfungal PCR over culture (88.2%; 76-94.7 vs 52.2%; 39-65, P = 0.001). Sub-analyses could not demonstrate the superiority of one PCR target over another due to limited data. Panfungal PCR exhibited adequate sensitivity and good specificity in FFPE samples. Sensitivity was even higher in non-fixed samples and largely superior to culture. Nevertheless, large interstudy variability was observed, warranting interlaboratory studies to define the optimal PCR target and standardized protocols. IMPORTANCE: Invasive fungal diseases are difficult to diagnose because of the low sensitivity of culture. Panfungal PCRs are widely used for fungal identification in tissue specimens but suffer from heterogeneous procedures and performance. This meta-analysis shows an acceptable sensitivity (75.4% and 86.5% in fixed and non-fixed samples, respectively) and good specificity (93.5%) of panfungal PCR, supporting its use, not only on histopathology-positive fixed samples but also in non-fixed samples concomitantly with other diagnostic tools (cultures and fungal-specific PCRs if available). These results provide a strong basis for further standardization of panfungal PCR techniques via interlaboratory assays to assess reproducibility and optimize analytical protocols. CLINICAL TRIALS: This study is registered with PROSPERO as CRD42023461148.

Humans

Molecular characterization of archival adrenal tumor tissue from patients with ACTH-independent Cushing syndrome.

Cushing syndrome represents a multitude of signs and symptoms associated with long-term and excessive exposure to glucocorticoids. Solitary cortisol-producing adenomas (CPAs) account for most cases of ACTH-independent Cushing syndrome (CS). Technological advances in next-generation sequencing have significantly increased our understanding about the genetic landscape of CPAs. However, the conventional approach utilizes fresh/frozen tissue samples, which are not routinely available for most clinical adrenal adenoma specimens. This coupled with the fact that CS is relatively rare reduces the accessibility to CPAs for research. In order to circumvent this issue, our group recently developed a sequencing strategy that allowed the use of formalin-fixed paraffin-embedded (FFPE) CPA samples for mutation analysis. Our streamlined approach includes the visualization and genomic DNA (gDNA) capture of the cortisol-producing regions in the tumor using immunohistochemistry (IHC)-guided techniques followed by targeted and/or whole-exome sequencing analysis. This approach has the advantage of using both prospective and retrospective CPA cohorts since FFPE pathologic specimens are routinely banked. This review discusses this advanced approach using IHC-guided gDNA capture of pathologic tissue followed by NGS as a preferred method for mutational analysis of CPAs.

Humans