Overexpression Of Annexin 1 In Pancreatic Cancer And Its Clinical Significance

Pancreatic cancer is a virulent disease with a poor prognosis since the asymptomatic nature of the disease in early stage and lack of effective diagnostic markers. Discovering dysregulated proteins during the development and progression of pancreatic cancer to find new therapy targets is a key approach to solve the problem. It is worthy noticing that annexin 1, a member of annexin family, was found significantly up-regulated in pancreatic cancer by three separate and independent gene expression profiles analysis using oligonucleotide array and cDNA microarray, which suggested that annexin 1 might be a candidate pancreatic cancer biomarker. In order to characterize the changes of annexin 1 expression in pancreatic cancer, in this study, we investigated the expression of annexin 1 and its roles in the pancreatic cancer using Western blot, tissue-array immunohistochemistry, 2-DE and RT-PCR to analys the expression of Annexin 1 in pancreatic cancer in both peotein and mRNA level.Western blot revealed that annexin 1 was low or undetectable expression in normal pancreas tissues. The level of annexin 1 expression was markedly increased in pancreatic ductal adenocarcinoma. Annexin 1 overexpression was found in 73% (8/11) pancreatic ductal adenocarcinoma tissues. There was also a strong annexin 1 expression in pancreatic cancer cell line in all of the immunoblot experiments, protein loading was normalized by reblotting the same membranes using a-tubulin as a housekeeping protein. Immunohistochemical analysis of annexin 1 was stydied by pancreatic cancer tissue microarray. In the normal pancreas, the positive expression rate of annexin 1 was 18.4% (7/38). It was found that most of normal pancreatic acinar and ductal cells were negative annexin 1 expression. There were only a small number of scattered acinar cells that were observed cytoplasmic annexin...