Screening Serum Biomarkers For Pancreatic Cancer By Serum Proteomics Techniques

Background: Pancreatic carcinoma has become one of the most common malignant tumors in the digestive tract and has the lowest survival rate compared to any other solid cancer. During the last 2 decades, the incidence of pancreatic carcinoma in the world is rising. However, the 5-year survival of patients with pancreatic carcinoma has not improved significantly. Currently, there are lack of markers for early detection and targets for therapy. The process of cancer initiation, progression, and formation of metastasis are not sufficiently understood. The proteomic approach has offered many opportunities for identifying new tumor markers and therapeutic targets, as well as well understanding pathogenesis of the disease.Objective: Pancreatic carcinoma has become one of the most common malignant tumors in the digestive system.We investigated the aberrant expression of serum proteins in patients with pancreatic cancer,to search differentially expressed proteins that might serve as serum biomarkers for pancreatic carcinoma. Some proteins may be involved in the possible candidate biomarkers for early diagnosis of pancreatic carcinoma and to gain new insight into the pathological mechanisms of tumor formation and development.Methods: Serum samples from 6 pancreatic carcinoma patients, 6 healthy volunteers were obtained.The top 14 high-abundance serum proteins were removed by use of an immuno-affinity column, and low-abundance ones were separated by two-dimensional gel electrophoresis (2-DE). The significantly differentially expressed proteins were analyzed by Ultraflex II MALDI-TOF-TOF mass spectrometer.Peptide mass fingerprints (PMFs) obtained by the MALDI-TOF-TOF analysis were used to search SWISS-PROT database by using Mascot software.Result: Protein in serum of each case was successfully separated on 2D gels.Among seventy-eight differently expressed protein ,fifty-four proteins were successfully identified by MS; twenty-nine of these were up-regulated in tumors and twenty-five down-regulated in tumors. Conclusion: There were significant difference in serum protein expression between patients with pancreatic cancer and healthy volunteers.And some of the differentially expressed proteins found by the proteomic approach may be potential molecular targets for pancreatic cancer diagnosis.