Pancreatic cancer remains one of the most deadly human malignancies. During the past decade, unprecedented progress has been made identifying the genetic basis for this disease, including the discovery of a number of common somatic mutations now confirmed to play important pathogenic roles. However, the recent application of whole genome deletion analysis and high throughput DNA sequencing has accelerated the rate of novel mutation detection well beyond any ability to functionally evaluate identified candidate genes. This mismatch between gene discovery and functional annotation will only increase with the completion of the already in-progress sequencing of the pancreatic cancer genome, an effort currently being pursued by investigators here at Johns Hopkins. In order to alleviate this bottleneck, and provide a system for higher throughput annotation of the pancreatic cancer genome, we have generated the first zebrafish model of exocrine pancreatic cancer. Based on the low costs and modest floorspace required to maintain adult zebrafish, as well as the ability to rapidly generate large numbers of transgenic lines, this organism offers many advantages in evaluating the molecular basis of human cancer. When an oncogenic version of human KRAS is expressed in developing zebrafish pancreas, pancreatic progenitor cells fail to undergo normal exocrine differentiation, leading to the subsequent formation of invasive pancreatic cancer. Zebrafish pancreatic cancers invade and metastasize, and exhibit many features in common with the human form of the disease, including abnormal activation of hedgehog signaling. In addition creating the first zebrafish model of exocrine pancreatic cancer, we have successfully generated transgenic lines in which a modified Gal4 transcriptional activator is expressed in pancreatic progenitor cells. Using transposon technology to insert UAS-regulated transgenes into the zebrafish genome, we now have the opportunity to functionally evaluate a wide variety of genetic lesions for their ability to modify pancreatic cancer initiation and/or progression, achieving a level of throughput not technically feasible in the mouse. Using these techniques, we now plan to pursue the following Specific Aims: First, to functionally annotate candidate dominant mutations identified in the pancreatic cancer genome, through their modular introduction into the zebrafish tumorigenesis model;second, to study the effects of graded changes in hMYC expression in pancreatic tumorigenesis, using an inducible Gal4/UAS system targeting progenitor cells in zebrafish exocrine pancreas;and third, to develop Cre-based models of KRAS-mediated pancreatic neoplasia in zebrafish. Together, these studies will provide important new information regarding the genetic basis for pancreatic cancer, allowing for the more rapid development of effective targeted therapies.
Pancreatic cancer represents one of the most deadly human malignancies, with five year survival rates of less than 5% and no change in this figure over the past four decades. By determining the genetic basis for this disease, our program will generate clinically relevant information that is likely to directly impact on strategies for chemoprevention, early detection and treatment.
|Park, J T; Johnson, N; Liu, S et al. (2015) Differential in vivo tumorigenicity of diverse KRAS mutations in vertebrate pancreas: A comprehensive survey. Oncogene 34:2801-6|
|Rakheja, Dinesh; Chen, Kenneth S; Liu, Yangjian et al. (2014) Somatic mutations in DROSHA and DICER1 impair microRNA biogenesis through distinct mechanisms in Wilms tumours. Nat Commun 2:4802|
|Matthaei, Hanno; Wu, Jian; Dal Molin, Marco et al. (2014) GNAS sequencing identifies IPMN-specific mutations in a subgroup of diminutive pancreatic cysts referred to as "incipient IPMNs". Am J Surg Pathol 38:360-3|
|Chivukula, Raghu R; Shi, Guanglu; Acharya, Asha et al. (2014) An essential mesenchymal function for miR-143/145 in intestinal epithelial regeneration. Cell 157:1104-16|
|McAllister, Florencia; Bailey, Jennifer M; Alsina, Janivette et al. (2014) Oncogenic Kras activates a hematopoietic-to-epithelial IL-17 signaling axis in preinvasive pancreatic neoplasia. Cancer Cell 25:621-37|
|Bailey, Jennifer M; Alsina, Janivette; Rasheed, Zeshaan A et al. (2014) DCLK1 marks a morphologically distinct subpopulation of cells with stem cell properties in preinvasive pancreatic cancer. Gastroenterology 146:245-56|
|Krzeszinski, Jing Y; Wei, Wei; Huynh, HoangDinh et al. (2014) miR-34a blocks osteoporosis and bone metastasis by inhibiting osteoclastogenesis and Tgif2. Nature 512:431-5|
|Patel, Kalpesh; Kern, Scott E (2013) "Selective cell death mediated by small conditional RNAs" is not selective. Cancer Biol Ther 14:693-6|
|Streppel, Mirte Mayke; Pai, Shweta; Campbell, Nathaniel R et al. (2013) MicroRNA 223 is upregulated in the multistep progression of Barrett's esophagus and modulates sensitivity to chemotherapy by targeting PARP1. Clin Cancer Res 19:4067-78|
|Mendell, Joshua T; Olson, Eric N (2012) MicroRNAs in stress signaling and human disease. Cell 148:1172-87|
Showing the most recent 10 out of 35 publications