Application of 2D-DIGE to formalin-fixed diseased tissue samples from hospital repositories: results from four case studies

Proteomics Clin Appl. 2013 Apr;7(3-4):252-63. doi: 10.1002/prca.201200054. Epub 2013 Mar 6.

Abstract

Purpose: In the recent past, the potential suitability of fixed samples to 2D-DIGE studies has been demonstrated on model tissues, but not on "real-world" archival tissues. Therefore, this study was aimed to assess the quality of the results delivered by 2D-DIGE on samples retrieved from hospital tissue repositories.

Experimental design: Diseased and normal tissue samples (namely, human gastric adenocarcinoma and normal gastric tissue, human lung neuroendocrine tumors, canine mammary tubulo-papillary carcinoma and normal mammary tissue, sheep liver with cloudy swelling degeneration and normal liver tissue) were retrieved from human and veterinary biorepositories and subjected to full-length protein extraction, cyanine labeling, 2D-DIGE separation, image analysis, MS analysis, and protein identification.

Results: Archival samples could be successfully subjected to 2D-DIGE, providing maps of satisfactory resolution, although with varying pattern complexity (possibly influenced by preanalytical variables). Moreover, differentially expressed protein identities were consistent with the disease biology.

Conclusions and clinical relevance: 2D-DIGE can support biomarker discovery and validation studies on large sample cohorts. In fact, although some information complexity is lost when compared to fresh-frozen tissues, their vast availability and the associated patient information can considerably boost studies suffering limited sample availability or involving long-distance exchange of samples.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biomarkers / analysis*
  • Dogs
  • Formaldehyde / chemistry*
  • Humans
  • Lung Neoplasms / chemistry
  • Paraffin Embedding
  • Proteins / analysis
  • Proteomics
  • Sheep
  • Small Cell Lung Carcinoma / chemistry
  • Tissue Banks
  • Tissue Fixation / methods*
  • Two-Dimensional Difference Gel Electrophoresis

Substances

  • Biomarkers
  • Proteins
  • Formaldehyde