Project description:Pancreatic cancer is one of the most deadly cancers with a 5 year survival rate of about 5%. Therapeutic options are limited, especially for patients that present with late state disease and metastasis. Although the metastatic burden of pancreatic cancer is usually high, little is known about the mechanisms that regulate delamination and dissemination of epithelial cells from preinvasive and malignant pancreatic lesions. Here, we used a preinvasive mouse model of pancreatic cancer to conditionally knockout p120 catenin (Ctnnd1). Mice with biallelic loss of p120 catenin progressively develop high grade PanIN lesions and neoplasia accompanied by prominent acute and chronic inflammatory processes. Loss of p120 catenin in the context of oncogenic Kras also promotes remarkable apical and basal epithelial cell extrusion. Abundant single epithelial cells exit PanIN epithelium basally, survive, and display features of malignancy. Similar extrusion defects are observed following p120 catenin knockdown in vitro, and these effects are completely abrogated by activation of S1P/S1P2 signaling. Our results establish p120 catenin and S1P/S1P2 signaling as novel regulators of non-EMT mediated epithelial cell invasion in pancreatic neoplasia. Transcriptomes of KCiMist1G; p120wt/wt and KCiMist1G; p120f/f pancreases were compared, with three replicates each, using microarray.
Project description:Pancreatic cancer is one of the most deadly cancers with a 5 year survival rate of about 5%. Therapeutic options are limited, especially for patients that present with late state disease and metastasis. Although the metastatic burden of pancreatic cancer is usually high, little is known about the mechanisms that regulate delamination and dissemination of epithelial cells from preinvasive and malignant pancreatic lesions. Here, we used a preinvasive mouse model of pancreatic cancer to conditionally knockout p120 catenin (Ctnnd1). Mice with biallelic loss of p120 catenin progressively develop high grade PanIN lesions and neoplasia accompanied by prominent acute and chronic inflammatory processes. Loss of p120 catenin in the context of oncogenic Kras also promotes remarkable apical and basal epithelial cell extrusion. Abundant single epithelial cells exit PanIN epithelium basally, survive, and display features of malignancy. Similar extrusion defects are observed following p120 catenin knockdown in vitro, and these effects are completely abrogated by activation of S1P/S1P2 signaling. Our results establish p120 catenin and S1P/S1P2 signaling as novel regulators of non-EMT mediated epithelial cell invasion in pancreatic neoplasia.
Project description:The Adherens Junction protein p120-catenin is implicated in the regulation of cadherin stability, cell migration and inflammatory responses in mammalian epithelial tissues. How these events are coordinated to promote wound repair is not understood. We show that p120-catenin regulates the intrinsic migratory properties or primary mouse keratinocytes, but also influences the migratory behavior of neighboring cells by secreted signals. These events are rooted in the ability of p120-catenin to regulate RhoA-GTPase activity, which leads to a two-tiered control of cell migration. One restrains cell motility via increase of actin stress fibers, reduction in integrin turnover, and an increase in focal adhesions robustness. The other is coupled to the secretion of inflammatory cytokines including Interleukin-24, which causally enhances randomized cell movements. Taken together, our results indicate that p120-RhoA-GTPase-mediated signaling can differentially regulate the migratory behavior of epidermal cells, which has potential implications for chronic wound responses and cancer.
Project description:We found that BAP1 (BRCA1 Associated Protein-1) shows loss of heterozygosity in over 25% of pancreatic cancer patients and functions as tumor suppressor. Conditional deletion of Bap1 in murine pancreas led to genomic instability, accumulation of DNA damage, and an inflammatory response that evolved to pancreatitis with full penetrance. Concomitant expression of oncogenic KrasG12D led to malignant transformation and development of invasive and metastatic pancreatic cancer. At the molecular level, BAP1 maintains the integrity of the exocrine pancreas by regulating genomic stability and its loss confers sensitivity to radio- and platinum-based therapies.
Project description:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.
Project description:The aim of the study was to investigate whether the trefoil peptide genes, in concerted action with a miRNA regulatory network, were contributing to nutritional maintrenance. Using a Tff2 knock-out mouse model, 48 specific miRNAs were noted to be significantly deregulated when compared to the wild type strain.
Project description:The aim of the study was to investigate whether the trefoil peptide genes, in concerted action with a miRNA regulatory network, were contributing to nutritional maintrenance. Using a Tff3 knock-out mouse model, 21 specific miRNAs were noted to be significantly deregulated when compared to the wild type strain.
Project description:Although early developmental processes involve cell fate decisions that define the body axes and establish progenitor cell pools, development does not cease once cells are specified. Instead, most cells undergo specific maturation events where changes in the cell transcriptome ensure that the proper gene products are expressed to carry out unique physiological functions. Pancreatic acinar cells mature post-natally to handle an extensive protein synthetic load, establsih organized apical-basal polarity for zymogen granule trafficking, and assemble gap-junctions to perimt efficient cell-cell communication. Despite significant progress in defining transcriptional networks that control initial acinar cell specification and differentiation decisions, little is know regarding the role of transcription factors in the specification and maintenance of maturation events. One candidate maturation effector is MIST1, a secretory cell-restricted transcription factor that has been implicated in controlling regulated exocytosis events in a number of cell types. Embryonic knock-out of MIST1 generates acinar cells that fail to establish an apical-basal organization, fail to properly localize zymogen granule and fail to communicate intra-cellularly, making the exocrine organ highly suceptible to pancreatic diseases. In an effort to identify the gene expression differences responsible for MIST1 regulating mature acinar properties. We generated a tamoxifen-inducible mouse model where MIST1 expression could be activated in vivoand performed gene expression arrays on wildtype, MIST1-null, and induced MIST1 pancreatic RNA.