| Pancreatic cancer, as a highly malignant gastroenterology cancer and its survival rate of5years no more than5%, is characterized by dismal prognosis due to the rapid disease progression and highly invasive tumour phenotype. New cases of pancreatic cancer were about200thousand each year and corresponded to2.1%of all new cancer cases. Pancreatic cancer resulted to196thousand patients and corresponded to3.4%of all deaths from cancer. Pancreatic cancer is the eighth cause of cancer-related death all over the world. Pancreatic cancer is not sensitive to radiotherapy and chemotherapy, the early diagnosis and tumor radical surgery is expected to the only effective way which may increase the survival rate of patients. Nowadays the level of early diagnosis of pancreatic cancer is very poor, the sensitivity and specificity of tumor marker CA19-9for tumor early diagnosis can not be satisfactory. Imaging examination revealed abnormal usually means advanced disease, patients may lose the early timing of surgery. Thus, the identification of adequate biomarkers in pancreatic cancer is of extremly important. In addition, the relationship of pancreatic cancer and chronic pancreatitis is not yet clear, and there are some reports about stent treatment but few is about the change of protein in the stent treatment. Protein is the material executant and embodiment of life. The studies on the pathogenesis of pancreatic cancer prefer to proteomics and sieving sensitive and specific biomarkers. A novel technique, surface enhanced laser desorption/ionization-time of flight-mass spectrometry (SELDI-TOF-MS) carved out a new path to proteomics research on pancreatic cancer. It can directly get high-throughput protein profilings from clinical samples with high sensitivity and this is the main advantage of this technique. SELDI-TOF-MS is composed by the protein chip system and mass spectrometer, which is especially suitable for low-abundance detection of proteins or peptides. Cancer detection should adopt SELDI-TOF MS technique with high sensitivity and without the need of previous protein purification from samples. In addition, the technique is applying on other diseases, such as heart disease, kidney transplant, AIDS, Alzheimer's disease and so on.The purpose of this study is to sieve novel tumor biomarkers of pancreatic cancer which are fit for diagnosis in early stage in pancreatic juice. And further analysis of the differences proteomics before and after chronic pancreatitis treated by pancreatic duct. This study was composed of two parts. Firstly, sieved tumor biomarkers and found out diagnostic models of pancreatic cancer by SELDI-TOF-MS and bioinformatics tools. Secondly, analysis the differences of proteomics before and after chronic pancreatitis treated by pancreatic stent.Part â… :The Application of Pancreatic Juice Protein Fingerprints on Pancreatic CancerObjective:To evaluate the pancreatic juice Proteomic differences in pancreatic cancer and chronic pancreatitis by SELDI-TOF-MS technique, and look for protein markers in early diagnosis of pancreatic cancer. Methods:1. ERCP pancreatic duct intubation extracted the pancreatic juice of pancreatic cancer and chronic pancreatitis, pretreating specimens2. Protein chip and pancreatic juice samples were all pretreated, plus the energy absorbing molecule (EAM), set the SELDI mass spectrometer parameters and data processingResults:1. Six cases of pancreatic juice samples from pancreatic cancer and eight cases of pancreatic juice samples from chronic pancreatitis, Non-parametric (the Wilcoxson T-test) test screening p-value less than0.05difference in protein.2.402protein peaks were detected by filter the signal to noise ratio and stressed the high quality of MS protein peaks,20protein peaks were of significant difference (P <0.05).16protein peaks in pancreatic cancer were significantly higher than the chronic pancreatitis group:1944.039m/z,1263.395m/z,1231.336m/z,3140.118m/z,1244.721m/z,4354.719m/z,1224.074m/z,4252.905m/z,7922.402m/z,2359.206m/z,1875.959m/z,1438.699m/z,4557.361m/z,2090.424m/z,3864.683m/z,1867.903m/z.4protein peaks in the chronic pancreatitis group were significantly higher than pancreatic cancer:2003.693m/z,3652.22m/z,1982.035m/z,13209.86m/z.3. T-test, Mann-Whitney rank test choose3protein peaks which were most capable to identify the two groups. The best combination has been calculated to filter out two groups:m/z1231.336,m/z2090.424. The pattern builded by this two protein peaks achieved the best detection results. The accuracy, sensitivity, specificity of blinded validation of the test set was100%,100%,100%.4. Bioinformatics identified a variety of proteins, included neuropeptides, CD24, tRNA methyltransferase, which have significant differences in pancreatic cancer and chronic pancreatitis'pancreatic juice.Conclusions:1.20distinct proteins peaks were found in pancreatic cancer and chronic pancreatitis, and m/z1231.336,m/z2090.424,m/z7922.402proteins peak were of the most significant difference.2. The pattern built by protein peak m/zl231.336,m/z2090.424could achieve the best detection results in identifying pancreatic cancer and chronic pancreatitis.3. CD24, tRNA methyltransferase in pancreatic juice of patients with pancreatic cancer was significantly higher than those in the chronic pancreatitis, revealed they may related to the occurrence of pancreatic cancer.4. The sensitivity and specificity of SELDI-TOF-MS technique is excellent, the results may have important implications for further study of proteomics of pancreatic cancer and its clinical diagnostic applications.Part II The Difference of Pancreatic Juice Protein Fingerprints Before and After the Stent on Chronic PancreatitisObjective:To evaluate proteomic differences in pancreatic juice before and after the stent in the treatment of chronic pancreatitis by SELDI-TOF-MS techniqueMethods:1. Extract the pancreatic juice of chronic pancreatitis by ERCP pancreatic duct intubation before and after stent treatment.2. Protein chip and pancreatic juice samples were all pretreated, plus the energy absorbing molecule (EAM), set the SELDI mass spectrometer parameters and data processing. Results:1. Eight cases of pancreatic juice samples was extracted before and after the stent on chronic pancreatitis. Nonparametric (the Wilcoxson T-test) test sieving proteins whose p-value was less than0.05.2.417protein peaks were detected by filter the signal to noise ratio and stressed the high quality of MS protein peaks,18protein peaks were of significant difference (P <0.05).7protein peaks before stent treatment group were significantly higher than the other group:941.1204m/z,1015.591m/z,2007.972m/z,2569.366m/z,2041.688m/z,2021.02m/z,5298.32m/z.11protein peaks after stent treatment group were significantly higher than the other group:5179.94m/z,5816.584m/z,5412.789m/z,2569.366m/z,1930.04m/z,4140.885m/z,6901.154m/z,10518.64m/z,6510.874m/z,7183.722m/z,5951.249m/z3. Bioinformatics identified a variety of proteins, included uPA, PYY, MT which have significant differences in chronic pancreatitis pancreatic juice after stent treatmentConclusions:1.18distinct proteins peaks were found in pancreatic juice of chronic pancreatitis before and after stent treatment2. UPA, PYY, MT may reflect pathophysiological improvement in chronic pancreatitis after stent treatment.3. SELDI-TOF-MS technique may have important implications for further study of proteomics in stent treatment on chronic pancreatitis because of its perfect sensitivity and specificity.
|
PDF Full Text Request