Project description:cis-Apc+/Delta716/Smad4+/- mice spontaneously develop multiple invasive intestinal carcinomas due to loss of heterozygosity and manifest symptoms associated with cancer cachexia within four months of age. To investigate the role of the liver in cachexia pathophysiology, we compared the transcriptomes of cachexia and control mouse livers. We isolated total RNA from livers of four C57BL/6N mice and four cis-Apc+/Delta716/Smad4+/- mice. Total RNA samples were then employed to perform microarray analysis (Agilent SurePrint G3 Mouse GE 8x60K Microarray).
Project description:Inactivation of TGF-beta family signaling is implicated in colorectal tumor progression. Using the cis-Apc/Smad4 mutant mice, a model of invasive colorectal cancer whose TGF-beta family signaling is blocked, we demonstrate here that a novel type of immature myeloid cells (iMCs) is recruited from the bone marrow to the tumor invasion front. These CD34+ iMCs express MMP9/2 and CC-chemokine receptor 1 (CCR1), and migrate toward its ligand CCL9. In the adenocarcinomas, expression of CCL9 is increased in the tumor epithelium. Such changes in the chemokine expression or the CD34+ iMC recruitment are not observed in the Apc (+/–) mice, a model of adenomatous polyposis. By knocking out Ccr1 gene in the cis-Apc/Smad4 mutant mice, we further demonstrate that lack of CCR1 prevents the accumulation of CD34+ iMCs at the invasion front and suppresses tumor invasion. These results indicate that loss of the TGF-beta family signaling in tumor epithelium causes accumulation of iMCs that help tumor invasion. Keywords: disease state analysis
Project description:To characterize the genetic basis of hybrid male sterility in detail, we used a systems genetics approach, integrating mapping of gene expression traits with sterility phenotypes and QTL. We measured genome-wide testis expression in 305 male F2s from a cross between wild-derived inbred strains of M. musculus musculus and M. m. domesticus. We identified several thousand cis- and trans-acting QTL contributing to expression variation (eQTL). Many trans eQTL cluster into eleven ‘hotspots,’ seven of which co-localize with QTL for sterility phenotypes identified in the cross. The number and clustering of trans eQTL - but not cis eQTL - were substantially lower when mapping was restricted to a ‘fertile’ subset of mice, providing evidence that trans eQTL hotspots are related to sterility. Functional annotation of transcripts with eQTL provides insights into the biological processes disrupted by sterility loci and guides prioritization of candidate genes. Using a conditional mapping approach, we identified eQTL dependent on interactions between loci, revealing a complex system of epistasis. Our results illuminate established patterns, including the role of the X chromosome in hybrid sterility.
Project description:To characterize the genetic basis of hybrid male sterility in detail, we used a systems genetics approach, integrating mapping of gene expression traits with sterility phenotypes and QTL. We measured genome-wide testis expression in 305 male F2s from a cross between wild-derived inbred strains of M. musculus musculus and M. m. domesticus. We identified several thousand cis- and trans-acting QTL contributing to expression variation (eQTL). Many trans eQTL cluster into eleven M-bM-^@M-^Xhotspots,M-bM-^@M-^Y seven of which co-localize with QTL for sterility phenotypes identified in the cross. The number and clustering of trans eQTL - but not cis eQTL - were substantially lower when mapping was restricted to a M-bM-^@M-^XfertileM-bM-^@M-^Y subset of mice, providing evidence that trans eQTL hotspots are related to sterility. Functional annotation of transcripts with eQTL provides insights into the biological processes disrupted by sterility loci and guides prioritization of candidate genes. Using a conditional mapping approach, we identified eQTL dependent on interactions between loci, revealing a complex system of epistasis. Our results illuminate established patterns, including the role of the X chromosome in hybrid sterility. Gene expression was measured in whole testis in males aged 70(M-BM-15) days. Samples include 294 WSB/EiJ x PWD/PhJ F2s, 11 PWD/PhJ x WSB/EiJ F2s, 8 WSB/EiJ, 8 PWD/PhJ, 6 PWD/PhJ x WSB/EiJ F1s and 4 WSB/EiJ x PWD/PhJ F1s.
Project description:To investigate the function of SETD2 in SMAD4-mutant colorectal cancer, we induced colorectal cancer in mice with intestinal epithelium-specific knockout of SMAD4 and SETD2 using AOM/DSS treatment.
Project description:To investigate the function of SETD2 in SMAD4-mutant colorectal cancer, we induced colorectal cancer in mice with intestinal epithelium-specific knockout of SMAD4 and SETD2 using AOM/DSS treatment.
Project description:Constitutive activation of the Wnt pathway leads to adenoma formation, an obligatory step towards intestinal cancer. In view of the established role of Wnt in regulating stemness, we attempted the isolation of cancer stem cells (CSCs) from Apc- and Apc/KRAS-mutant intestinal tumours. Whereas CSCs are present in malignant Apc/KRAS–mutant carcinomas, they appear to be very rare (<10-6) in the benign Apc–mutant adenomas. In contrast, the Lin-CD24hiCD29+ subpopulation of adenocarcinoma cells appear to be enriched in CSCs with increased levels of active -catenin. Expression profiling analysis of the CSC-enriched subpopulation confirmed their enhanced Wnt activity and revealed additional differential expression of other signalling pathways, growth factor binding proteins, and extracellular matrix components. As expected, genes characteristic of the Paneth cell lineage (e.g. defensins) are co-expressed together with stem cell genes (e.g. Lgr5) within the CSC-enriched subpopulation. This is of interest as it may indicate a cancer stem cell niche role for tumor-derived Paneth-like cells, similar to their role in supporting Lgr5+ stem cells in the normal intestinal crypt. Overall, our results indicate that oncogenic KRAS activation in Apc-driven tumours results in the expansion of the CSCs compartment by increasing b-catenin intracellular stabilization. To identify molecular differences between stem-like and more differentiated (bulk) tumour cells from Apc1638N/+ and Apc1638N/+/KRASV12G intestinal adenomas and adenocarcinomas, we isolated total RNA from 104 Lin-CD24hiCD29+, Lin-CD24medCD29+/Lin-CD24loCD29+ and Lin- (bulk) tumour cells from 5 individual mice of each genotype (Apc1638N/+ and Apc1638N/+/KRASV12G). Total RNA samples were then employed to hybridize oligonucleotide microarrays (Affymetrix Mouse Genome 430A 2.0 Array) according to conventional protocols.