Project description:Synovial sarcoma is a deadly soft-tissue malignancy with a predilection for adolescents and young adults. Mice recapitulate synovial sarcomagenesis from expression of SS18-SSX2 in certain cells. Concomitant expression of a stabilized form of beta-catenin enhances synovial sarcomagenesis and expands the potential cells of origin. Mice bearing conditional expression of SS18-SSX2 from the Rosa26 locus and conditional excision of the 3rd exon of beta-catenin, each activated in the leg by Cre-recombinase expressed from an adeno-associated viral vector, formed large tumors at brief latency.
Project description:Synovial sarcoma is a deadly soft-tissue malignancy with a predilection for adolescents and young adults. Mice recapitulate synovial sarcomagenesis from expression of SS18-SSX2 in certain cells. Concomitant expression of a stabilized form of beta-catenin enhances synovial sarcomagenesis and expands the potential cells of origin.
Project description:Deregulation of canonical Wnt/beta-catenin pathway is one of the earliest events in the pathogenesis of colon cancer. Mutations in APC or CTNNB1 (beta-catenin gene) are highly frequent in colon cancer and cause aberrant stabilization of b-catenin, which activates the transcription of Wnt target genes by binding to chromatin via the TCF/LEF transcription factors. Here we report an integrative analysis of genome-wide chromatin occupancy of b-catenin by chromatin immunoprecipitation coupled with high-throughput sequencing (ChIP-seq) and gene expression profiling by microarray analysis upon RNAi-mediated knockdown of beta-catenin in colon cancer cells (GSE53656). Immunoprecipitated samples from human colon cancer SW480 cells with antibodies against beta-catenin and control IgG respectively were used for ChIP-seq experiments.
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:Gain-of-function mutations in exon 3 of beta-catenin (CTNNB1) are specific for Wilms' tumors that have lost WT1, but 50% of WT1-mutant cases lack such "hot spot" mutations. To ask whether stabilization of beta-catenin might be essential after WT1 loss, and to identify downstream target genes, we compared expression profiles in WT1-mutant versus WT1 wild-type Wilms' tumors. Supervised and nonsupervised hierarchical clustering of the expression data separated these two classes of Wilms' tumor. The WT1-mutant tumors overexpressed genes encoding myogenic and other transcription factors (MOX2, LBX1, SIM2), signaling molecules (TGFB2, FST, BMP2A), extracellular Wnt inhibitors (WIF1, SFRP4), and known beta-catenin/TCF targets (FST, CSPG2, CMYC). Beta-Catenin/TCF target genes were overexpressed in the WT1-mutant tumors even in the absence of CTNNB1 exon 3 mutations, and complete sequencing revealed gain-of-function mutations elsewhere in the CTNNB1 gene in some of these tumors, increasing the overall mutation frequency to 75%. Lastly, we identified and validated a novel direct beta-catenin target gene, GAD1, among the WT1-mutant signature genes. These data highlight two molecular classes of Wilms' tumor, and indicate strong selection for stabilization of beta-catenin in the WT1-mutant class. Beta-Catenin stabilization can initiate tumorigenesis in other systems, and this mechanism is likely critical in tumor formation after loss of WT1. Experiment Overall Design: Identification of WNT/Beta-Catenin or WT1 target genes. 39 individual samples.
Project description:We used microarrays to detail the gene expression profile during WAT -beige transition by treatment of beta adrenergic receptor agonist .
Project description:β-Catenin is a regulator of cutaneous wound repair. The expression of genes that are modulated in response to changes in β-Catenin levels (stabilization and downregulation) in cutaneous mouse wounds, post injury, during the proliferative phase of repair, was investigated. We are particularly interested in genes that are modulated (in opposite directions) in response to both the induction (stabilization) versus downregulation of β-Catenin. To investigate this, conditional β-Catenin stabilized (Harada, N., et al. EMBO J. 1999 Nov 1;18(21):5931-42) mice were injected with either a Cre-expressing adenovirus, or a GFP-expressing control virus, three days following injury, and wounds were harvested eight days post injury. For conditional knockdown of β-Catenin, mice generated from a cross between conditional β-Catenin knockdown mice (Brault, V. et al., Development. 2001 Apr;128(8):1253-64), and mice that express a tamoxifen-inducible form of Cre (Hayashi, S., and McMahon, A.P., Dev Biol. 2002 Apr 15;244(2):305-18), were treated with Tamoxifen for five days, beginning at the third day after injury. Wounds were harvested eight days after wounding. This provides insight into the identities of genes modulated in response to changes in β-Catenin levels during the proliferative stage of cutaneous wound repair.
Project description:Genome wide expression profiling to determine the overlap of Affymetrix-signals with SOLID sequencing RNA was extracted using the Qiagen RNeasy kit following the manufacturers guidelines, arrays were prepared and hybridized following the Affymetrix protocol.