Identification of pancreatic juice proteins as biomarkers of pancreatic cancer

Abstract

Abstract. Pancreatic juice is a potential source of proteins associated with pancreatic cancer (PC) due to the proximity of ducts to tumor tissue. Therefore, screening of proteins in pancreatic juice from PC patients may identify new PC biomarkers. We analyzed pancreatic juice from patients with pancreatic diseases including PC, chronic pancreatitis (CP) and simple choledocholithiasis (CDS) by 2-DE. Protein spots from PC patients that changed >2-fold compared with both CP and CDS were selected and identified by mass spectrometry (MS). mRNA levels were measured by QRT-PCR in PC cell lines, PC tissues and adjacent pancreatic normal (PN) tissues. Relationships between mRNA levels in PC tissues and their clinical characteristics and promoter methylation were analyzed in PC cell lines and tissues. We found that four proteins were significantly changed in PC compared to CP and simple CDS. Two proteins were up-regulated, serine proteinase-2 (PRSS2) preproprotein and pancreatic lipaserelated protein-1 (PLRP1), and two proteins were downregulated, chymotrypsinogen B (CTRB) precursor and elastase 3B (ELA3B) preproprotein. In all PC cell lines, PRSS 2 mRNA levels were elevated, while PLRP 1 mRNA was detected in 4/5 cell lines. ELA3B mRNA was undetectable in all cell lines, but CTRB mRNA was detected in 2/5 cell lines. In PC tissues compared to PN, levels of PRSS2 mRNA were significantly higher, ELA3B significantly lower, and PLRP1 and CTRB not significantly different. Elevated PRSS2 mRNA levels correlated with high T stage. The ELA3B gene promoter had higher methylation in PC cell lines and tissues compared with PN tissues, and correlated with low ELA3B gene expression. In conclusion, comparative proteomic analysis of pancreatic juice from PC patients is a powerful method to find new PC biomarkers. Hyperexpression of the PRSS2 gene and hypermethylation of ELA3B gene promoter were associated with PC, raising the possibility of their application as new biomarkers in PC diagnosis and screening.

Fibronectin and β-Catenin Act in a Regulatory Loop in Dermal Fibroblasts to Modulate Cutaneous Healing

“…This suggests involvement of the ␤1-integrin-associated integrin-linked kinase (59 -61). In cells of epithelial origin (9,11,62,63) and in natural killer cells (64), ␤-catenin is modulated in response to extracellular matrix and/or integrin stimulation by tyrosine phosphorylation and consequent liberation from cadherin binding. The activation of ␤-catenin released from E-cadherin by integrin signaling is not associated with GSK3␤ (11,63).…”

Evaluation of the suitability of archival Bouin‐fixed paraffin‐embedded tissue specimens to proteomic investigation

“…two-fold SpCs in the neoplastic compared to the control tissue) also in the FFPE samples. Moreover, most of these were known to be specifically expressed in gastric cancer, such as protein S100-A6 [29,30], type-I collagen [31,32], nucleoside diphosphate kinase [33], protein S100-A8 [34,35], cofilin [36], and peptidyl-prolyl cis-trans isomerase A [37], as well as (among those with lower log ratio in FFPE samples) biglycan [38], galectin-3 [39,40], and tenascin [41]. Furthermore, other proteins known as underexpressed in cancer (particularly those involved in electron transport and oxidative phosphorylation, such as cytochromes and ATP synthase subunits, according to the so-called Warburg effect [42][43][44]) were consistently found as much more abundant in normal tissue than in gastric adenocarcinoma BFPE samples (Supporting Information S2).…”