Dataset Information

Systematic Evaluation and Optimization of Protein Extraction Parameters in Diagnostic FFPE Specimens

ABSTRACT: Objectives: Formalin-fixed paraffin-embedded (FFPE) tissue is the standard material for di-agnostic pathology but poses relevant hurdles to accurate protein extraction due to cross-linking and chemical alterations. While numerous extraction pro-tocols and chemicals have been described, systematic comparative analyses are limited. Various parameters were thus investigated in their qualitative and quantitative effects on protein extraction (PE) efficacy. Special emphasis was put on preservation of membrane proteins (MP) as key subgroup of func-tionally relevant proteins. Methods: Using the example of urothelial carcinoma, FFPE tissue sections were subjected to various deparaffinization, protein extraction and antigen retrieval protocols and buffers as well as different extraction techniques. Performance was meas-ured by protein concentration and western blot analysis of cellular compart-ment markers as well as liquid chromatography-coupled mass spectrometry (LC-MS). Results: Commercially available extraction buffers showed reduced extraction of MPs and came at considerably increased costs. On-slide extraction did not improve PE whereas several other preanalytical steps could be simplified. Systematic variation of temperature and exposure duration demonstrated a quantitatively relevant corridor of optimal antigen retrieval. Conclusions: Preanalytical protein extraction can be optimized at various levels to improve unbiased protein extraction and to reduce time and costs.

INSTRUMENT(S): TripleTOF 5600

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Urinary Bladder

SUBMITTER: Franz Friedrich Dressler

LAB HEAD: Franz Dressler

PROVIDER: PXD029133 | Pride | 2022-05-19

REPOSITORIES: Pride

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Publications

Systematic evaluation and optimization of protein extraction parameters in diagnostic FFPE specimens.

Dressler Franz F FF Schoenfeld Jana J Revyakina Olga O Vogele Daniel D Kiefer Selina S Kirfel Jutta J Gemoll Timo T Perner Sven S

Clinical proteomics 20220502 1

<h4>Objectives</h4>Formalin-fixed paraffin-embedded (FFPE) tissue is the standard material for diagnostic pathology but poses relevant hurdles to accurate protein extraction due to cross-linking and chemical alterations. While numerous extraction protocols and chemicals have been described, systematic comparative analyses are limited. Various parameters were thus investigated in their qualitative and quantitative effects on protein extraction (PE) efficacy. Special emphasis was put on preservati ...[more]

PMID: 35501693

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Project description:As proteins represent cell function, proteomic analysis of prostate tissues may elucidate the mechanisms of prostate cancer (PCa) progression. To that end, formalin-fixed paraffin-embedded (FFPE) tissues are valuable resources, but associated with large analytical difficulties due to protein cross-linking. Our aim is to characterize tissue protein changes associated with castration resistant PCa. This study focused at the development of a reliable protocol for the proteomic analysis of FFPE tissues which was followed by a pilot study using FFPE PCa clinical samples to investigate whether the optimized protocol can provide biologically relevant data in the context of PCa. Archival FFPE mouse tissues were processed using seven protein extraction protocols including combinations of homogenization means (beads, sonication, boiling) and buffers (Tris-HCl and Urea-Thiourea). The proteomics output was evaluated by SDS electrophoresis and high resolution LC-MS/MS analysis. FFPE tissues (3 sections, 15��m each per sample) from 10 patients with PCa corresponding to tumor (GS=6 or GS��8) and adjacent benign regions were processed with the optimized protocol. Extracted proteins were analyzed by GeLC-MS/MS followed by statistical and bioinformatics analysis using Cytsoscape and Open Targets tool. A combination of cell lysis by Tris-HCl, SDS and DTE with bead homogenization, sonication and boiling provided most efficient protein extraction from FFPE tissues based on protein identifications and reproducibility. Comparison between the FFPE and matched FF tissues showed a substantial overlap in protein identifications (502 common out of 1,216 IDs commonly identified in all FF samples and 530 IDs commonly identified in all FFPE samples) with a strong correlation in relative abundances (rs=0.846, p<.001). Proteins significantly deregulated between PCa GS��8 and PCa GS=6 represented extracellular matrix organisation, phosphorylation and gluconeogenesis pathways, while proteins deregulated between cancerous tissues and benign counterparts, reflected increased translation, peptide synthesis and protein metabolism in the former, as expected. Further disease association analysis using the Open Targets platform showed that 60% of the differentially expressed proteins in cancer versus normal adjacent were significantly associated with PCa. These results support the relevance of the proteomic findings in the context of PCa and the reliability of the optimized protocol for proteomics analysis of FFPE material. A large scale study including 160 clinical FFPE prostate cancer and benign tissues to define protein changes associated with aggressive PCa, is planned.

Dataset Information

Systematic Evaluation and Optimization of Protein Extraction Parameters in Diagnostic FFPE Specimens

Publications

Systematic evaluation and optimization of protein extraction parameters in diagnostic FFPE specimens.

Similar Datasets

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