Project description:Background: PTEN loss contributes to the development of many cancers and is associated with both hepatocellular carcinoma and cholangiocarcinoma. The pathogenesis of these malignancies is unclear, but they are speculated to arise from common cellular origins. We explored the influence of secondary effects, like hypoxia signaling, through co-deletion of Pten and Vhl in a murine model.Methods: We used a CreER-linked keratin 18 mouse model to conditionally delete Pten, Vhl or both, evaluating the resultant tumors by histology and gene expression microarray. A cohort of human cholangiocarcinoma samples was evaluated for relationships between HIF-1a expression and clinical outcomes.Results: Both Pten deletion genotypes developed liver tumors, but with differing phenotypes. Pten deletion alone led to large, invasive tumors with widespread hepatosteatosis. Co-deletion of Pten and Vhl resulted in low tumor burden and reduced steatosis. Microarray analysis divided mouse tumors’ respective genotypes by gene expression. This gene expression profile grouped a human tumor cohort according to histologic type with the Pten deletion signature aligning with hepatocellular carcinoma, whereas the Pten; Vhl deletion signature associated with cholangiocarcinomas. In a human cholangiocarcinoma cohort, we observed correlation between HIF-1a expression and overall survival.Conclusions: Pten deletion leads to tumor formation and steatosis in mouse livers. Co-deletion of Vhl and Pten resulted in lower tumor burden with gene expression profiling suggesting a switch from hepatocellular expression features to an expression profile more consistent with cholangiocarinoma. A possible relation between HIF-1a expression and increased overall survival in human cholangiocarcinoma suggests that hypoxia signaling influences tumor phenotype. reference x sample
Project description:Background: PTEN loss contributes to the development of many cancers and is associated with both hepatocellular carcinoma and cholangiocarcinoma. The pathogenesis of these malignancies is unclear, but they are speculated to arise from common cellular origins. We explored the influence of secondary effects, like hypoxia signaling, through co-deletion of Pten and Vhl in a murine model.Methods: We used a CreER-linked keratin 18 mouse model to conditionally delete Pten, Vhl or both, evaluating the resultant tumors by histology and gene expression microarray. A cohort of human cholangiocarcinoma samples was evaluated for relationships between HIF-1a expression and clinical outcomes.Results: Both Pten deletion genotypes developed liver tumors, but with differing phenotypes. Pten deletion alone led to large, invasive tumors with widespread hepatosteatosis. Co-deletion of Pten and Vhl resulted in low tumor burden and reduced steatosis. Microarray analysis divided mouse tumors’ respective genotypes by gene expression. This gene expression profile grouped a human tumor cohort according to histologic type with the Pten deletion signature aligning with hepatocellular carcinoma, whereas the Pten; Vhl deletion signature associated with cholangiocarcinomas. In a human cholangiocarcinoma cohort, we observed correlation between HIF-1a expression and overall survival.Conclusions: Pten deletion leads to tumor formation and steatosis in mouse livers. Co-deletion of Vhl and Pten resulted in lower tumor burden with gene expression profiling suggesting a switch from hepatocellular expression features to an expression profile more consistent with cholangiocarinoma. A possible relation between HIF-1a expression and increased overall survival in human cholangiocarcinoma suggests that hypoxia signaling influences tumor phenotype.
Project description:We found that deleting Pten in Albumin expressing cells results in liver steatosis as early as 1 month of age. The mice develop hyperplasia and tumor phenotypes starting at 7-8 months of age. At 12 months and beyond, all mice develope spontanous liver tumors of mixed lineage phenotypes dihydrocollidine (DDC) shows that the primary effect of AKT2 loss is attenuation of hepatic injury and not inhibition of progenitor cell proliferation in response to injury. Pten is deleted specifically in the liver (Pten loxP/loxP; Alb-Cre+). Liver tissues were analyzed at 3 months (steatosis stage) and 15 months (tumor stage)
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:SILAC based protein correlation profiling using size exclusion of protein complexes derived from Mus musculus tissues (Heart, Liver, Lung, Kidney, Skeletal Muscle, Thymus)
Project description:SILAC based protein correlation profiling using size exclusion of protein complexes derived from seven Mus musculus tissues (Heart, Brain, Liver, Lung, Kidney, Skeletal Muscle, Thymus)
Project description:RNA-sequencing analysis of liver gene expression after combinatorial liver-specific deletion of tumor suppressor genes in a mouse fatty liver disease and liver cancer model. Gene expression was determined at 16 weeks of age, before onset of liver tumor formation. Aim was to study how loss of atypical E2F transcription repressors affected gene expression in Pten-mutant livers.