Project description:Mutations of subunit genes of the SWI/SNF chromatin remodeling complexes were found in 12-23% of human Pancreatic Ductal Adenocarcinoma (PDAC). We previously showed that Brg1, a catalytic ATPase subunit of the SWI/SNF chromatin remodeling complexes, inhibits the formation of intraductal pancreatic mucinous neoplasms (IPMN) and IPMN-derived PDAC from ductal cells. On the other hand, ARID1A is the most frequent target of mutations in the SWI/SNF chromatin remodeling complexes in human PDAC. We found that Arid1a loss in the context of mutant Kras resulted in formation of IPMN and PDAC. We also found that the incidence of PDAC formation in Ptf1a-Cre; KrasG12D; Arid1af/f mice was markedly lower than that in Ptf1a-Cre; KrasG12D; Brg1f/f mice despite the similarities between Arid1a-deficient and Brg1-deficient IPMNs. We extracted total RNA from intraductal papillary mucinous neoplasms (IPMNs) in Ptf1a-Cre; KrasG12D; Arid1af/f and Ptf1a-Cre; KrasG12D; Brg1f/f mice and perform microarray analysis.
Project description:Mutations in members of the SWI/SNF chromatin remodeling family are common events in human cancer, but the mechanisms whereby disruption of SWI/SNF components alters tumorigenesis remain poorly understood. To model the effect of loss of function mutations in the SWI/SNF subunit Arid1a in pancreatic ductal adenocarcinoma (PDAC) initiation, we directed shRNA triggered, inducible and reversible suppression of Arid1a to the pancreas of mice in the setting of oncogenic KrasG12D. Arid1a cooperates with Kras in the adult pancreas as postnatal silencing of Arid1a following sustained KrasG12D expression induces rapid and irreversible reprogramming of acinar cells into mucinous PDAC precursor lesions. In contrast, Arid1a silencing during embryogenesis, concurrent with KrasG12D activation, leads to retention of acinar cell fate. Together, our results demonstrate Arid1a as a critical modulator of Kras-dependent changes in acinar cell identity, and underscore an unanticipated influence of timing and genetic context on the effects of SWI/SNF complex alterations in epithelial tumorigenesis.
Project description:Mutations in members of the SWI/SNF chromatin remodeling family are common events in human cancer, but the mechanisms whereby disruption of SWI/SNF components alters tumorigenesis remain poorly understood. To model the effect of loss of function mutations in the SWI/SNF subunit Arid1a in pancreatic ductal adenocarcinoma (PDAC) initiation, we directed shRNA triggered, inducible and reversible suppression of Arid1a to the pancreas of mice in the setting of oncogenic KrasG12D. Arid1a cooperates with Kras in the adult pancreas as postnatal silencing of Arid1a following sustained KrasG12D expression induces rapid and irreversible reprogramming of acinar cells into mucinous PDAC precursor lesions. In contrast, Arid1a silencing during embryogenesis, concurrent with KrasG12D activation, leads to retention of acinar cell fate. Together, our results demonstrate Arid1a as a critical modulator of Kras-dependent changes in acinar cell identity, and underscore an unanticipated influence of timing and genetic context on the effects of SWI/SNF complex alterations in epithelial tumorigenesis.
Project description:The aim of this experiment is to unravel PDAC biology and phospho-print based on aberrant kinase activities and proteome alterations. For this we will perform pTYyrIP, Bravo_IMAC, and protein expression data of n=56 tissues encompassing 47 pancreatic ductal adenocarcinoma (PDAC), 5 cholangiocarcinoma, 1 Intraductal Papillary Mucinous Neoplasm (IPMN), 1 pancreatitis and 1 pancreatitis-Pancreatic Intraepithelial Neoplasia (PanIN) tissue. Pancreatitis, PanIN, and IPMN are seen as early events predecessing PDAC. An equiproportional pool of 5 PDAC cell lines (PANC1, SUIT-2, CFPAC-1, HPAC, MIAPACA2) is also taken along.
