Expression and clinical significance of AHSG and complement C3 in pancreatic ductal adenocarcinoma

Abstract

To analyze serum proteins from pancreatic carcinoma patients, pancreatic benign tumor patients, chronic pancreatitis patients and normal controls to discover potential and specific biomarkers. Serum samples were collected from 40 pancreatic carcinoma patients, 10 pancreatic benign tumor patients, 10 chronic pancreatitis patients and 40 cancer-free controls from May 2009 to April 2011. The samples were compared with two-dimensional differential gel electrophoresis (2D-DIGE) and differentially expressed proteins were further identified by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS). Then, two up-regulated proteins were further validated by real-time polymerase chain reaction (PCR), Western blot analysis and immunohistochemistry (IHC) from transcriptional and proteinic aspects. We identified 12 differently expressed proteins in pancreatic carcinoma group compared with normal control group, including complement component C3, hemopexin, alpha-2-HS-glycoprotein, apolipoprotein H, serotransferrin, haptoglobin, apolipoprotein E, transthyretin, serum amyloid P-component, vitronectin, prothrombin and isoform 2 of Ig mu chain C region. High level of C3 and AHSG were detected in cancerous tissues by real-time PCR, Western blot and immunohistochemisty. Western blot revealed that gray ratios of C3 and AHSG were 0.11 ± 0.01 and 0.26 ± 0.02 respectively. The Immunohistochemical results showed that positive rate of C3 and AHSG were 72.5% and 82.5% in cancerous group versus 32.5% and 25% respectively in normal control. C3 and AHSG may become pancreatic carcinoma-related biomarkers.