Tatjana Crnogorac-Jurcevic and her colleagues from Barts Cancer Institute, Queen Mary University of London (QMUL) and MS Bioworks report on progress in understanding pancreatic ductal adenocarcinoma (PDAC), a major cause of cancer-related death. Dr. Crnogorac-Jurcevic from the Molecular Oncology center at Barts used proteomics to study primary tumors and matched lymph node (LN) metastases. The study was carried on out on archived formalin-fixed paraffin-embedded (FFPE) tissue samples. Using laser capture microdissection, malignant epithelia were isolated from seven FFPE primary PDAC tumours and matched LN metastases. Following dissection, samples were analyzed in duplicate using Multidimensional Protein Identification Technology (MudPIT); this resulted in the identification of 1504 proteins, 854 of which were common to all samples analyzed. Comparison of the obtained proteins with data from previous proteomics studies on pancreatic tissue, pancreatic juice, serum, and urine resulted in a less than 30% overlap, indicating that our study has substantially expanded the current database of proteins expressed in this malignancy.
Statistical analysis further showed that 115/854 proteins (13.5%) were significantly differentially expressed (g-value ?3.8). Two proteins, S100P and 14-3-3 sigma, with highly significant g-values were confirmed to be significantly differentially expressed (S100P: p = 0.05 and 14-3-3 sigma: p < 0.001) in a larger series of 55 cases of matched primary PDAC and LN metastases using immunohistochemistry.
Congratulations to Tatjana and her colleagues for this significant contribution to our understanding of this devastating disease. More details of this work are available in the complete article “Proteome of Formalin-Fixed Paraffin-Embedded Pancreatic Ductal Adenocarcinoma and Lymph Node Metastases” Naidoo et al. J. Pathology, 226, 756 (2012).