A timecourse analysis of the genetic extinction of NRAS in an inducible mouse model of melanoma.
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE39985 | GEO | 2012/08/09
SECONDARY ACCESSION(S): PRJNA172205
REPOSITORIES: GEO
Similar Datasets
Project description:We sought to understand the pathways involved in NRAS extinction over time using a doxycycline-dependent, inducible mouse model of melanoma. This data provides insights into the temporal dynamics of downstream NRAS signaling and helps to correlate differentially affected pathways. We used microarrays to determine which transcripts were affected by NRAS-Q61K extinction at 24, 48, and 72 hours after doxycycline withdrawal. This data was used in support of a separate dataset submitted to GEO entitled Comparison of the genetic extinction of NRAS to pharmacological MEK inhibition in an inducible mouse model of melanoma. The iNRAS-475 mouse melanoma cell line was injected intradermally into nude mice which were fed 2mg/ml doxycycline water. Tumors were allowed to reach 200-500mm3 after 6 weeks. Doxycyline was then withdrawn from the diet and tumors harvested at 24, 48, and 72 hours post-withdrawal.
2012-08-08 | E-GEOD-39985 | biostudies-arrayexpress
Project description:Since direct pharmacological inhibition of RAS has thus far been unsuccessful, we explored system biology approaches to identify synergistic drug combination(s) that can mimic direct RAS inhibition. Leveraging an inducible mouse model of NRAS-mutant melanoma, we compare pharmacological MEK inhibition to complete NRAS-Q61K extinction in vivo. NRAS-Q61K extinction leads to a complete and durable tumor regression by enhancing both apoptosis and cell cycle arrest. By contrast, MEK inhibition only produces tumor stasis at best and we find that it robustly activates apoptosis but does not significantly impede proliferation. We used microarrays to determine which transcripts were affected by NRAS-Q61K extinction but insufficiently by MEK inhibition. We selected a single comparative timepoint, 4 days post-treatment. Downstream analyses included GSEA and TRAP algorithms, leading to the identification of a differentially affected CDK4-driven proliferation network. Immune genes were also identified as significant, but control experiments determined these to be largely the off-target effects of doxycycline and not of NRAS-Q61K extinction. The iNRAS-475 mouse melanoma cell line was injected intradermally into nude mice which were fed 2mg/ml doxycycline water. Tumors were allowed to reach 200-500mm3 after 6 weeks. Mice were then treated with vehicle or 100mg/kg of the AZD6244 MEK inhibitor, or doxycyline was withdrawn from the diet. Each sample represents a distinct tumor and thus provide six biological, not technical replicates per cohort.
2012-08-08 | E-GEOD-39984 | biostudies-arrayexpress
Project description:Since direct pharmacological inhibition of RAS has thus far been unsuccessful, we explored system biology approaches to identify synergistic drug combination(s) that can mimic direct RAS inhibition. Leveraging an inducible mouse model of NRAS-mutant melanoma, we compare pharmacological MEK inhibition to complete NRAS-Q61K extinction in vivo. NRAS-Q61K extinction leads to a complete and durable tumor regression by enhancing both apoptosis and cell cycle arrest. By contrast, MEK inhibition only produces tumor stasis at best and we find that it robustly activates apoptosis but does not significantly impede proliferation. We used microarrays to determine which transcripts were affected by NRAS-Q61K extinction but insufficiently by MEK inhibition. We selected a single comparative timepoint, 4 days post-treatment. Downstream analyses included GSEA and TRAP algorithms, leading to the identification of a differentially affected CDK4-driven proliferation network. Immune genes were also identified as significant, but control experiments determined these to be largely the off-target effects of doxycycline and not of NRAS-Q61K extinction.
2012-08-09 | GSE39984 | GEO
Project description:This SuperSeries is composed of the following subset Series: GSE39984: Comparison of the genetic extinction of NRAS to pharmacological MEK inhibition in an inducible mouse model of melanoma [4 days post-treatment] GSE39985: A timecourse analysis of the genetic extinction of NRAS in an inducible mouse model of melanoma. Refer to individual Series
2012-08-08 | E-GEOD-39987 | biostudies-arrayexpress
Project description:To study the role of NRAS mutations in cell proliferation and self-renewal in acute myeloid leukemia (AML), the human AML cell line, THP1, was modified to replace its naturally occurring heterozygous NRAS-G12D mutation with a doxycycline(dox)-inducible heterozygous NRAS-G12V mutation. The endogenous copies of the NRAS-G12D allele were deleted using CRISPR/Cas9 after a dox-inducible, CRISPR resistant, NRAS-G12V transgene was introduced into the THP1 cell line. The resulting cell line was named B11. RNA-seq data confirmed that endogenous NRAS G12D was successfully replaced by dox-inducible exogenous NRAS G12V in the B11 cell line. As expected, depletion of dox induced G1 cell cycle arrest. Interestingly, the B11 cells experienced ten-times higher expression of NRAS induced G2/S-phase cell cycle arrest. Forty-nine genes were identified as signaling responsible genes associated with high expression of NRAS.
2022-07-25 | GSE115911 | GEO
Project description:Targeted therapies have the potential to revolutionize cancer care by providing personalized treatment strategies that are less toxic and more effective but it is clear that for most solid tumors suppression of a single target is not sufficient to prevent development of resistance. A powerful method to identify mechanisms of resistance and targets for combination therapy is to use an in vivo genetic approach. We have developed a novel retroviral gene delivery mouse model of melanoma that permits control of gene expression post-delivery using the tetracycline (tet)-regulated system. In this study we used this melanoma model to select for resistant tumors following genetic inhibition of mutant NRAS. Analysis of tumors that became resistant to NRAS suppression revealed that the most common mechanism of resistance was overexpression of the Met receptor tyrosine kinase (RTK). Importantly, inhibition of Met overcomes NRAS resistance in this context. Analysis of NRAS mutant human melanoma cells revealed that inhibition of MEK is also associated with adaptive RTK signaling. Furthermore, co-inhibition of RTK signaling and MEK overcomes acquired MEK inhibitor resistance in NRAS mutant melanoma. These data suggest that combined inhibition of RTK and MEK signaling is a rational therapeutic strategy in mutant NRAS driven melanoma. Reversible NRAS Q61R expression in the melanocytes of DCT-TVA;Ink4a/Arf lox/lox mice (FVB/n) was achieved by transducing the animals with Tet-off and TRE-NRASQ61R-IRES-Cre avian leukosis viruses. After tumor initiation, the expression of NRAS Q61R was turned off by administrating doxycycline. Despite initial regression, tumors in 40% of mice developed resistance to NRAS Q61R withdraw. Seven resistant tumors and one control tumor where NRAS Q61R expression was not interrupted were subjected to genome-wide gene expression profiling.
2014-10-31 | E-GEOD-51906 | biostudies-arrayexpress
Project description:Mutations in the NRAS oncogene are present in up to 20% of melanoma. Here, we show that interferon alpha-inducible protein 6 (IFI6) is necessary for NRASQ61K-induced transformation and melanoma growth. IFI6 was transcriptionally upregulated by NRASQ61K, and knockdown of IFI6 resulted in DNA replication stress due to dysregulated DNA replication via E2F2. This stress consequentially inhibited cellular transformation and melanoma growth via senescence or apoptosis induction depending on the RB and p53 pathway status of the cells. NRAS-mutant melanoma were significantly more resistant to the cytotoxic effects of DNA replication stress-inducing drugs, and knockdown of IFI6 increased sensitivity to these drugs. Pharmacological inhibition of IFI6 expression by the MEK inhibitor trametinib, when combined with DNA replication stress-inducing drugs, blocked NRAS-mutant melanoma growth. Collectively, we demonstrate that IFI6, via E2F2 regulates DNA replication and melanoma development and growth, and this pathway can be pharmacologically targeted to inhibit NRAS-mutant melanoma.
2016-09-08 | GSE69933 | GEO
Project description:Mutations in the NRAS oncogene are present in up to 20% of melanoma. Here, we show that interferon alpha-inducible protein 6 (IFI6) is necessary for NRASQ61K-induced transformation and melanoma growth. IFI6 was transcriptionally upregulated by NRASQ61K, and knockdown of IFI6 resulted in DNA replication stress due to dysregulated DNA replication via E2F2. This stress consequentially inhibited cellular transformation and melanoma growth via senescence or apoptosis induction depending on the RB and p53 pathway status of the cells. NRAS-mutant melanoma were significantly more resistant to the cytotoxic effects of DNA replication stress-inducing drugs, and knockdown of IFI6 increased sensitivity to these drugs. Pharmacological inhibition of IFI6 expression by the MEK inhibitor trametinib, when combined with DNA replication stress-inducing drugs, blocked NRAS-mutant melanoma growth. Collectively, we demonstrate that IFI6, via E2F2 regulates DNA replication and melanoma development and growth, and this pathway can be pharmacologically targeted to inhibit NRAS-mutant melanoma. YUGASP cells stably expressing a non-silencing shRNA or two individual shRNAs against IFI6 were used to prepare the total RNA, which was then used to analyze for gene expression using Illumina expression array.
2016-09-08 | E-GEOD-69933 | biostudies-arrayexpress
Project description:Activating mutations in NRAS account for 15-20% of melanoma, yet effective anti-NRAS therapies are still lacking. In this study, we unveil the casein kinase 1δ (CK1δ) as an uncharacterized regulator of oncogenic NRAS mutations, specifically Q61R and Q61K, which are the most prevalent NRAS mutations in melanoma. The genetic ablation or pharmacological inhibition of CK1δ markedly destabilizes NRAS mutants and suppresses their oncogenic functions. Moreover, we identify USP46 as a bona fide deubiquitinase of NRAS mutants. Mechanistically, CK1δ directly phosphorylates USP46 and activates its deubiquitinase activity towards NRAS mutants, thus promoting oncogenic NRAS-driven melanocyte malignant transformation and melanoma progression in vitro and in vivo. Our findings underscore the significance of the CK1δ-USP46 axis in stabilizing oncogenic NRAS mutants and provide preclinical evidence that targeting this axis holds promise as a therapeutic strategy for human melanoma harboring NRAS mutations.
2024-09-19 | PXD051431 | Pride
Project description:Activating mutations in NRAS account for 20-30% of melanoma, yet effective anti-NRAS therapies are still lacking. In this study, we unveil the casein kinase 1δ (CK1δ) as an uncharacterized regulator of oncogenic NRAS mutations, specifically Q61R and Q61K, which are the most prevalent NRAS mutations in melanoma. The genetic ablation or pharmacological inhibition of CK1δ markedly destabilizes NRAS mutants and suppresses their oncogenic functions. Moreover, we identify USP46 as a bona fide deubiquitinase of NRAS mutants. Mechanistically, CK1δ directly phosphorylates USP46 and activates its deubiquitinase activity towards NRAS mutants, thus promoting oncogenic NRAS-driven melanocyte malignant transformation and melanoma progression in vitro and in vivo. Our findings underscore the significance of the CK1δ-USP46 axis in stabilizing oncogenic NRAS mutants and provide preclinical evidence that targeting this axis holds promise as a therapeutic strategy for human melanoma harboring NRAS mutations.
2024-09-20 | PXD046277 | Pride