Project description:Comparison of wild type mouse cancer cell lines to transfected cell lines with IKKA, IKKB, Kras sh RNA and treated with Il-1b mouse protein
Project description:The cell lines in this study are a combination of internally sequenced (cosmic) and externally sequenced cell lines known to be “double-wild-type” (lacking BRAF and NRAS somatic mutations). These sequences were realigned in this data set for consistency.
Project description:We have transfected a new tumor suppresor gene named ARLTS1 in A549 lung cancer cell line that shows a very low expression level in comparison with normal lung. This line was transfected using the pMV-7 vector containing the full length ARLTS1 coding sequence (transfected cell lines denoted FL1 to FL4), the C-terminus deleted cDNA (transfectants denoted Stop1 to Stop3) or the control (empty) vector. The expression profile was compared between the FL and Stop clones, using the wild-type as reference.
Project description:<p>Although multi-agent combination chemotherapy is curative in a significant fraction of childhood acute lymphoblastic leukemia (ALL) patients, 20% of cases relapse and most die due to chemo-refractory disease. Here we used whole-exome and whole-genome sequencing to analyze the mutational landscape and pattern of clonal evolution at relapse in pediatric ALL cases. These analyses showed that ALL relapses originate from a common ancestral precursor clone of the diagnosis and relapsed populations and frequently harbor mutations implicated in chemotherapy resistance. RAS-MAPK pathway activating mutations in NRAS, KRAS and PTPN11 were present in 24/55 (44%) cases in our series. Notably, while some cases showed emergence of RAS mutant clones at relapse, in others, RAS mutant clones present at diagnosis were replaced by RAS wild type populations. Mechanistically, functional dissection of mouse and human wild type Kras and mutant Kras (Kras G12D) isogenic leukemia cells demonstrated induction of methotrexate resistance, but also improved response to vincristine, in mutant Kras- expressing lymphoblasts. These results identify chemotherapy driven selection as a central mechanism of leukemia clonal evolution and pave the road for the development of tailored personalized therapies for the treatment of relapsed ALL. </p>
Project description:Purpose: Emerging evidence in the field of RAS biology is beginning to illustrate that RAS mutations are functionally distinct. To elucidate functional differences between NRAS mutants we performed RNA-sequencing on mouse embryonic fibroblasts (MEFs) expressing different NRAS codon 61 variants from the endogenous gene locus Methods: MEFs were isolated from Tyr::CRE-ERT2 LSL-Nras mouse models containing different Nras variants in the endogeous gene locus. NRAS expression was induced in MEFs using an Adenoviral Cre delivery system. RNA was isolated from MEFs six days post-NRAS induction and submitted for RNA-sequencing Results: Differential expression and gene set enrichment analysis (GSEA) between NRAS variants revealed enrichment of transcripts associated with cellular proliferation between all mutant Nras alleles versus wild-type Nras. Further, MEFs expressing NRAS mutants capable of driving melanoma formation were enriched for transcripts associated with RAS-MYC signaling axis. Conclusion: While all NRAS mutants are capable of enhancing cellular proliferation versus wild-type NRAS, the melanomagenic potential of these mutants correlates with the ability to enhance activation of the RAS-MYC signaling axis
Project description:Despite recent therapeutic advances in the management of BRAFV600-mutant melanoma, there is still a compelling need for more effective treatments for patients who developed BRAF/NRAS wild type disease. Since the activity of single targeted agents is limited by innate and acquired resistance, we performed a high-throughput drug screen using 180 drug combinations to generate over 17,000 viability curves, with the aim of identifying agents that synergise to kill BRAF/NRAS wild type melanoma cells. From this screen we identified a promising drug combination that efficiency kills 30% of melanoma cell lines. We validated in vivo the synergy of the drug combination and found a potential marker to identify sensitive tumors. We applied a genome-wide CRISPR screening which revealed that resistance mechanisms to the drug combination. In order to investigate the mechanism of drug synergy, we treated sensitive and resistance melanoma cell lines with the single drugs and the drug combination and performed proteome analyses to investigate the changes in total proteins and protein phosphorylation. These analysis highlighted specific pathway deregulations associated to the drug synergy that allowed to get a better understanding of the drug interaction and their efficacy in killing melanoma cell lines.
Project description:siRNA mediated DUSP4 silencing in a cell line derived from a) AKT/NRAS double injected hepatocellular carcinoma in a mouse by hydrodynamic injection => AKT/NRAS and b) these cell lines with Cre knockout for AKT => AKT/NRAS Cre
Project description:We performed microarray experiments to examine gene expression in human tissues. This data was used for comparison with our humanized mouse study (GEO ID GSE33846) and threshold determination of our tiling array data (GEO ID GSE18490, public in the near future). A total of 22 tissues (bone marrow, cerebellum, colon, cortex, fetal brain, heart, kidney, liver, lung, pancreas, prostate, salivary gland, skeletal muscle, small intestine, spinal cord, spleen, stomach, testes, thymus, thyroid, trachea and uterus) and 2 cell lines (HeLa and SH-SY5Y) were examined.