A New Microarray, Enriched in Pancreas and Pancreatic Cancer cDNAs to Identify Genes Relevant to Pancreatic Cancer

Background: Identification and characterization of genes that are relevant to pancreatic cancer remains a priority for developing detection and diagnostic tests and identifying targets for treatment. Materials and Methods: In order to discover relevant genes, we developed a microarray composed of 5763 pancreas and pancreatic cancer cDNA clones, representing genes of known and unknown function. The Pittsburgh Pancreas Enriched ARray (PittPEAR) was used to compare the gene expression differences between pancreatic cancer and normal pancreas. Results: Two hundred and sixty-four genes were identified: 85 were overexpressed and 176 were underexpressed in cancer compared to normal tissue. Two of the top five genes included the cell cycle division 37 (CDC37) and period Drosophila homolog protein 1 (PER1), which play critical roles in cell division and transcriptional regulation, respectively. Underexpression of many genes probably reflected the loss of acinar and islet cells from the tumors. The biological functions of overexpressed genes include immune response genes, cytoskeletal and genes related to the extracellular matrix, cell invasion, migration, adhesion and motility. Apoptosis and transcription factor genes were also identified. Conclusion: We conclude that the PittPEAR microarray provides a useful tool for identifying genes that are relevant to the development and maintenance of pancreatic cancer. Pancreatic cancer is the fourth leading cause of death due to cancer in virtually all industrialized countries (1). The American Cancer Society estimates that there will be 31,270 deaths in the United States in 2004. Pancreatic cancer is difficult to detect, hard to diagnose, early to metastasize and resistant to treatment. The vast majority of patients are incurable (96% to 99%). The median survival is 4 months while the 5-year survival rate is only 3 to 4% (2). These stark statistics emphasize the need for a better understanding of pancreatic cancer biology.