Oncogenic NRAS Signaling Differentially Regulates Survival and Proliferation in Melanoma.
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ABSTRACT: 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
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 Doxycyline was then withdrawn from the diet and tumors harvested at 24, 48, and 72 hours post-withdrawal.
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.
Project description:We analyze the globel gene expression changes in the tumor initiating cells of regressing miR-125b addicted tumors after oncomiR withdrawal For Histone-H2BGFP expression in DTG tumor cells, the U6 promoter was deleted in the PLKO-PGK-H2B-GFP vector throughNdeI-AgeI digestion, Quick Blunting Kit treatment (NEB), and self-ligation. The resulting PLNA-PGK-H2BGFP plasmid was packaged into lentivirus and used to infect ~1x106freshly sorted α6hiβ1hi DTG tumor cells. After 30 min, cells were then extensively washed and immediately engrafted onto backskins of Nude mice by intradermal transplantation. GFP+α6hiβ1hicells were FACS-isolated from resulting tumors and then serially transplanted as above. For RNA seq analysis of the miR-125b addicted tumor regression process, H2BGFP labeled DTG tumor cells were intradermally engrafted onto backskins of Nude mice (1x104cells/site). Tumors were allowed to grow to ~1cm diameter. Mice were then taken Off Dox by transferring them to regular food for 0, 4, 7 days. GFP+α6hiβ1hiwere then FACS-isolated from the tumors. Two or three independent replicates were collected for each time point. Total RNAswere extracted from the FACS-sorted cells using the miRNeasy Mini Kit (Qiagen) according to the vender’s protocol. Expression of miR-125b in each sample was quantified by RT-PCR using TaqMan MicroRNA Assays (Applied Biosystems). For RNA seq, RNA samples were submitted to the Genomics Resources Core Facility of the Weill Cornell Medical College for library construction using IlluminaTruSeq Stranded mRNA Sample Prep Kit and then sequencing using Illumina HiSeq2000. Resultswere analyzed via the Galaxy web platform using TopHat for initiate mapping and Cufflinks for transcripts assembling and expression level estimation (Computing FPKM: fragments per kilobase of exon per million fragments mapped). The MM9 genome assembly (UCSC Genome Browser) was used as reference genome for all analyses. Low expression genes
Project description:Human hepatocellular carcinoma cells were subcutaneously implanted into nude mice and treated with photodynamic nanoparticles (NP3) with laser, followed by tissue collection and proteomic analysis.
Project description:The goal of this study was to determine the effects of a well-characterized anti-androgen, abiraterone acetate, and a suspected human anti-androgen, di-n-butyl phthalate (DBP) on the androgenic function of human fetal testis. Human fetal testis was xenografted into the renal subcapsular space of castrated male athymic nude mice. Hosts were treated with hCG to stimulate testosterone production in the xenografts, and were concurrently treated with either abiraterone acetate or DBP. While abiraterone acetate (14 d, 75 mg/kg/d p.o.) dramatically reduced testosterone and the weights of androgen-sensitive host organs, DBP (14 d, 500 mg/kg/d p.o.) had no effect on androgenic endpoints. Three paired analyses were performed using the LIMMA package in R (commands lmfit and eBayes), with the Benjamini-Hochberg correction for multiple comparisons (Smyth 2005): vehicle-treated xenografts vs. unimplanted testis (n=5), abiraterone-treated xenografts vs. matched control xenografts (n=3), and DBP-treated xenografts vs. matched control xenografts (n=3). There were significant differences in gene expression between grafted and ungrafted samples, including dramatic upregulation of microRNAs. Gene expression analysis also showed that abiraterone decreased expression of genes related to cell differentiation, while DBP induced expression of oxidative stress response genes and decreased expression of factors related to embryonic development. 17 xenograft samples were analyzed, including 5 unimplanted samples, 6 vehicle treated xenografts, 3 abiraterone acetate-treated xenografts, and 3 DBP-treated xenografts. Samples were paired (derived from the same donor tissue) for each comparison: vehicle vs. unimplanted (n=5), abiraterone vs. vehicle (n=3), and DBP vs. vehicle (n=3).
Project description:We aimed at identifying lymphangiogenic subpopulations by comparative analysis of single cell clones derived from a melanoma of a single patient. Selected clones were grafted into SCID mice, where they induced lymphangiogenesis and metastasized into sentinel nodes, whereas non-lymphangiogenic clones from the same patient did not metastasize. RNA isolated from primary SCID mouse tumors were used for transcriptome analysis. A total of 16 Samples were analysed, 4 per group. Parental pool MCM1(C), nonlymphangiogenic MCM1G(G), lymphangiogenic MCM1D(D1), lymphangiogenic and very metastatic MCM1DLN(D2).
Project description:Increasing success is being achieved in the treatment of malignancies with stromal-targeted therapies, predominantly in anti-angiogenesis and immunotherapy, predominantly checkpoint inhibitors. Despite 15 years of clinical trials with anti-VEGF pathway inhibitors for cancer, we still find ourselves lacking reliable predictive biomarkers to select patients for anti-angiogenesis therapy. For the more recent immunotherapy agents, there are many approaches for patient selection under investigation. Notably, the predictive power of an Ad-VEGF-A164 mouse model to drive a stromal response with similarities to a wound healing response shows relevance for human cancer and was used to generate stromal signatures. We have developed gene signatures for 3 stromal states and leveraged the data from multiple large cohort bioinformatics studies of gastric cancer (TCGA, ACRG) to further understand how these relate to the dominant patient phenotypes identified by previous bioinformatics efforts. We have also designed multiplexed IHC assays that robustly represent the vascular and immune diversity in gastric cancer. Finally, we have used this methodology to arrive at a hypothesis of how angiogenesis and immunotherapy may fit into the experimental approaches for gastric cancer treatments. The Ad-VEGF-A164 angiogenesis model was performed as previously described. Animals were treated with various anti-VEGF Receptor antibodies via intraperitoneal injection at the doses (DC101 20 mpk or G6 10 mpk) and time points (day 0, day 5, day 20, day 60) to target all of the different populations of tumor-surrogate blood vessels, as they each develop at different time points. At least 5 animals, equally matched, were used per group. At the end of the experiment, angiogenic sites in flanks were photographed and tissues were taken for histology and RNA preparation.
Project description:This SuperSeries is composed of the following subset Series: GSE22005: Medulloblastoma tumors derived from Ptch+/-HIC+/- transgenic mouse allografted in nude mice GSE22006: Medulloblastoma tumors derived from Ptch+/-p53-/- transgenic mouse allografted in nude mice Refer to individual Series
Project description:Expression was generated on tumors from 41 iBIP mice, which were previously described (Kwong, JCI, 2015). The BRAF-driven iBIP mouse model of melanoma was taken off dox and expression analyzed at various timepoints.