Project description:During cancer evolution, cellular differentiation programs become dysregulated. The transcription factor Nkx2-1 is a master regulator of pulmonary differentiation that is downregulated in poorly differentiated lung adenocarcinoma. Here we use conditional murine genetics to study the fate of lung epithelial cells upon loss of their master cell fate regulator. Nkx2-1 deletion in normal and neoplastic lung causes not only loss of pulmonary identity but also gastric transdifferentiation. Nkx2-1 maintains pulmonary identity by sequestering the Foxa1 transcription factor at lung-specific loci and inhibiting Foxa1 binding to gastrointestinal targets. Murine Nkx2-1-negative lung tumors mimic the mucinous subtype of human lung adenocarcinoma, which also exhibits gastric transdifferentiation. Nkx2-1-negative lung adenocarcinomas are dependent on the gastrointestinal gene Hnf4a for efficient initiation. Thus, loss of Nkx2-1 results in transdifferentiation rather than stable dedifferentiation in vivo, suggesting that inactivation of both active and latent differentiation programs may be required for tumors to reach a primitive, dedifferentiated state. The study was designed to compare the expression profiles of Nkx2-1-positive lung adenocarcinomas with tumors in which Nkx2-1 was deleted at the time of initiation or 6-7 months after initiation.
Project description:Tissue-specific differentiation programs become dysregulated during cancer evolution. The transcription factor Nkx2-1 is a master regulator of pulmonary differentiation that is downregulated in poorly differentiated lung adenocarcinoma. Here we use conditional murine genetics to study the fate of lung epithelial cells upon loss of their master cell fate regulator. Nkx2-1 deletion in normal and neoplastic lung causes not only loss of pulmonary identity but also gastric transdifferentiation. Nkx2-1 maintains pulmonary identity by sequestering the Foxa1 transcription factor at lung-specific loci and by inhibiting Foxa1 binding to gastrointestinal targets. Murine Nkx2-1-negative lung tumors mimic the mucinous subtype of human lung adenocarcinoma, which also exhibits gastric transdifferentiation. Nkx2-1-negative lung adenocarcinomas are dependent on the gastrointestinal gene Hnf4a for efficient initiation. Thus, loss of Nkx2-1 causes transdifferentiation rather than stable dedifferentiation in vivo, suggesting that inactivation of both active and latent differentiation programs are required for tumors to reach a primitive, dedifferentiated state.
Project description:During cancer evolution, cellular differentiation programs become dysregulated. The transcription factor Nkx2-1 is a master regulator of pulmonary differentiation that is downregulated in poorly differentiated lung adenocarcinoma. Here we use conditional murine genetics to study the fate of lung epithelial cells upon loss of their master cell fate regulator. Nkx2-1 deletion in normal and neoplastic lung causes not only loss of pulmonary identity but also gastric transdifferentiation. Nkx2-1 maintains pulmonary identity by sequestering the Foxa1 transcription factor at lung-specific loci and inhibiting Foxa1 binding to gastrointestinal targets. Murine Nkx2-1-negative lung tumors mimic the mucinous subtype of human lung adenocarcinoma, which also exhibits gastric transdifferentiation. Nkx2-1-negative lung adenocarcinomas are dependent on the gastrointestinal gene Hnf4a for efficient initiation. Thus, loss of Nkx2-1 results in transdifferentiation rather than stable dedifferentiation in vivo, suggesting that inactivation of both active and latent differentiation programs may be required for tumors to reach a primitive, dedifferentiated state.
Project description:Tissue-specific differentiation programs become dysregulated during cancer evolution. The transcription factor Nkx2-1 is a master regulator of pulmonary differentiation that is downregulated in poorly differentiated lung adenocarcinoma. Here we use conditional murine genetics to study the fate of lung epithelial cells upon loss of their master cell fate regulator. Nkx2-1 deletion in normal and neoplastic lung causes not only loss of pulmonary identity but also gastric transdifferentiation. Nkx2-1 maintains pulmonary identity by sequestering the Foxa1 transcription factor at lung-specific loci and by inhibiting Foxa1 binding to gastrointestinal targets. Murine Nkx2-1-negative lung tumors mimic the mucinous subtype of human lung adenocarcinoma, which also exhibits gastric transdifferentiation. Nkx2-1-negative lung adenocarcinomas are dependent on the gastrointestinal gene Hnf4a for efficient initiation. Thus, loss of Nkx2-1 causes transdifferentiation rather than stable dedifferentiation in vivo, suggesting that inactivation of both active and latent differentiation programs are required for tumors to reach a primitive, dedifferentiated state. ChIP-seq data from murine lung adenocarcinomas on (i) transcription factors Nkx2-1 and Foxa in Nkx2-1-deleted tumors and Nkx2-1-positive control tumors, and (ii) four histone marks in Nkx2-1-deleted tumors and Nkx2-1-positive control tumors. (All samples in duplicate and with input controls, i.e. (2 x [(3+3) + (2+8)]) - 1 = 31 samples total - 1 input control used for transcription factor and histone mark, GSM1059357)
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: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.