Project description:Expression profile of KRAS transformed murine B cell progenitors and empty vector transduced counterparts by DNA microarray analysis
Project description:Rhabdomyosarcoma is a pediatric malignancy thought to arise from the uncontrolled proliferation of myogenic cells. Here, we have generated models of rhabdomyosarcoma in the zebrafish by inducing oncogenic KRASG12D expression at different stages during muscle development. Several zebrafish promoters were used including the cdh15 and rag2 promoters that drive gene expression in early muscle progenitors, and the mylz2 promoter that expresses in differentiating myoblasts. The tumors that developed differed in their ability to recapitulate normal myogenesis. cdh15:KRASG12D and rag2:KRASG12D fish developed tumors that displayed an inability to fully undergo muscle differentiation by histologic appearance and gene expression analyses. In contrast, mylz2:KRASG12D tumors more closely resembled mature skeletal muscle and were most similar to well-differentiated human rhabdomyosarcoma by gene expression. mylz2:KRASG12D fish showed significantly improved survival compared to cdh15:KRASG12D and rag2:KRASG12D fish. Tumor-propagating activity was enriched in myf5-expressing cell populations within all of the tumor types. Our results demonstrate that oncogene expression at different stages during muscle development has profound effects on the ability of tumor cells to recapitulate normal myogenesis, altering the tumorigenic capability of these cells. 32 samples total: 7 WT muscle, 9 mylz2-KRAS, 9 cdh15-KRAS, and 7 rag2-KRAS tumors
Project description:Rhabdomyosarcoma is a pediatric malignancy thought to arise from the uncontrolled proliferation of myogenic cells. Here, we have generated models of rhabdomyosarcoma in the zebrafish by inducing oncogenic KRASG12D expression at different stages during muscle development. Several zebrafish promoters were used including the cdh15 and rag2 promoters that drive gene expression in early muscle progenitors, and the mylz2 promoter that expresses in differentiating myoblasts. The tumors that developed differed in their ability to recapitulate normal myogenesis. cdh15:KRASG12D and rag2:KRASG12D fish developed tumors that displayed an inability to fully undergo muscle differentiation by histologic appearance and gene expression analyses. In contrast, mylz2:KRASG12D tumors more closely resembled mature skeletal muscle and were most similar to well-differentiated human rhabdomyosarcoma by gene expression. mylz2:KRASG12D fish showed significantly improved survival compared to cdh15:KRASG12D and rag2:KRASG12D fish. Tumor-propagating activity was enriched in myf5-expressing cell populations within all of the tumor types. Our results demonstrate that oncogene expression at different stages during muscle development has profound effects on the ability of tumor cells to recapitulate normal myogenesis, altering the tumorigenic capability of these cells.
Project description:Ras mutations are commonly observed in Juvenile Myelomonocytic Leukemia (JMML) and Chronic Myelomonocytic Leukemia (CMML). JMML and CMML transform into Acute Myeloid Leukemia (AML) in about 10% and 50% of patients respectively. However, how additional events cooperate with Ras to promote this transformation are largely unknown. We show that absence of the Ubiquitin-Specific-peptidase 22 (USP22), a component of the SAGA chromatin-remodeling complex linked to cancer progression, unexpectedly promotes AML transformation in mice expressing oncogenic KrasG12D/+. USP22 deficiency in KrasG12D/+ mice resulted in shorter survival compared to control mice. This was due to a block in myeloid cell differentiation leading to the generation of AML. This effect was cell autonomous since mice transplanted with USP22-deficient KrasG12D/+ cells developed an aggressive disease and died rapidly. The transcriptome profile of USP22-deficient KrasG12D/+ progenitors resembled leukemic stem cells and was highly correlated with genes associated with poor prognosis in AML. We show that USP22 functions as a PU.1 deubiquitylase by positively regulating its protein stability and promoting the expression of PU.1 target genes. Reconstitution of PU.1 overexpression in USP22-deficient KrasG12D/+ progenitors rescued their differentiation. Our findings uncovered an unexpected role for USP22 in Ras-induced leukemogenesis and provide further insights into the function of USP22 in carcinogenesis.
Project description:Experiment designed to study the effect of 1 or 2 copies of deregulated myc on transcriptional profile during pancreatic cancer progression. In the KRasG12D/RosaMycER mouse model KRas and MycER are expressed exclusively in the pancreas, but MycER activity depends on Tamoxifen presence. RNAseq was preformed on pancreatas from KRasG12D/RosaMycER+/- or KRasG12D/RosaMycER+/+ mice treated 12 hours with Tamoxifen.
Project description:Comparison of gene expression changes of pancreatic tissue from Ptf1aCre;KrasG12D and Ptf1aCre;KrasG12D;SnailKI/+ mice at the age of 1 month and 3 months.
Project description:Microarray expression data generated to compare the biological impact of KrasG12D allelic duplication in p53null mouse embryonic fibroblasts (MEFs). The RAS/MAPK-signalling pathway is frequently deregulated in non-small cell lung cancer (NSCLC), often through activating mutations in KRAS. Mouse models demonstrated that activation of a single endogenous mutant Kras allele is sufficient to promote lung tumour formation, but acquisition of other genetic alterations is required for malignant progression. Using a well-established lung cancer mouse model we recently demonstrated that advanced KrasG12D-driven spontaneous tumours frequently exhibit enhanced MAPK signalling and KrasG12D allelic enrichment (KrasG12D/Kraswild-type>1), implying that mutant Kras copy gains are positively selected during lung cancer progression. To compare the oncogenic impact of a single mutant allele versus additional mutant Kras copy gain, we carried out a comprehensive analysis of mutant Kras homozygous and heterozygous MEFs and lung cancer cells and show that these genotypes are phenotypically distinct. Title: Mutant Kras copy number defines metabolic reprogramming and therapeutic susceptibilities Authors: Emma M Kerr, Edoardo Gaude, Frances K Turrell, Christian Frezza and Carla P Martins
Project description:Background: Non-small cell lung cancer (NSCLC) accounts for 81% of all cases of lung cancer and they are often fatal because 60% of the patients are diagnosed at an advanced stage. Besides the need for earlier diagnosis, there is a great need for additional effective therapies. In this work we investigated the feasibility of a lung cancer progression mouse model, mimicking features of human aggressive NSCLC cancer, as biological reservoir for potential therapeutic targets and biomarkers. Results:RNA-seq profiling was performed on total RNA extracted from lungs of 30 week-old p53R172HM-bM-^HM-^Fg/KrasG12D and wild type mice to detect fusion genes and gene/exon-level differential expression associated to the increase of tumor mass. Fusion events were not detected in p53R172HM-bM-^HM-^Fg/KrasG12D tumors. Differential expression at exon-level detected 33 genes with differential exon usage. The study provides a complete transcription overview of the p53R172HM-bM-^HM-^Fg/KrasG12D mouse NSCLC model Lung mRNA profiles of 30-week old wild type (WT) and p53R172HM-bM-^HM-^Fg/KrasG12D mice were generated by deep sequencing, in duplicate using Illumina HiSeq2000.