Human renal cell carcinomas (RCC) have differential expression of HIF-1alpha and HIF-2alpha, depending on VHL genotype and other events.
HIF-alpha effects on c-Myc distinguish two subtypes of sporadic VHL-deficient clear cell renal carcinoma.
Sex, Age, Specimen part, Disease, Disease stage
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Oncogenic NRAS signaling differentially regulates survival and proliferation in melanoma.
Specimen part, Treatment
View SamplesSince 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.
Oncogenic NRAS signaling differentially regulates survival and proliferation in melanoma.
Specimen part
View SamplesWe 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.
Oncogenic NRAS signaling differentially regulates survival and proliferation in melanoma.
Specimen part, Treatment
View SamplesT-cell acute lymphoblastic leukemia (T-ALL) is an immature hematopoietic malignancy driven mainly by oncogenic activation of NOTCH1 signaling. In this study we used a mouse model of T-ALL through the overexpression of the intarcellular transcriptionally active part of Notch1 (N1-IC). This model faithfully recapitulates the major characteristics of the human disease. Comparison of the leukemic cells from peripheral tumors(thymoma) of this mouse model to normal thymic cells Double Positive (DP) for the markers CD4 and CD8 that express very low levels of Notch1 showed major expression changes in pathways controlling the transition from physiology to disease. Further correlation of the data to ChIP-Seq data from the same cell populations led us to identify a hitherto unknown antagonism of the Notch1 oncogenic pathway and the polycomb complex (PRC2) in leukemia. Importantly exome sequencing in primary samples from human patients with T-ALL revealed that the PRC2 complex is frequently mutated and inactivated, further supporting the tumor suppressor role of the complex in this disease.
Genetic inactivation of the polycomb repressive complex 2 in T cell acute lymphoblastic leukemia.
Specimen part, Disease
View SamplesTargeting components of the mitogen-activated protein kinase (MAPK) pathway prolongs survival of patients with advanced BRAFV600E melanomas but such an approach is not curative because of the rapid acquisition of numerous resistance mechanisms. Here we analyze melanoma cells that evade MAPK inhibitors by undergoing a senescence-like, slow-growth, phenotype, which leads to acquired resistance. The initial therapeutic response is characterized by an integrated stress response program, including stimulation of autophagic flux, activation of the endoplasmic reticulum machinery, and an enhanced ability of detoxifying reactive oxygen species. Reversibly senescent cells also exhibit an increase in mitochondrial genome copy number and a strong metabolic shift towards oxidative phosphorylation (OxPhos). Inducing mitochondrial dysfunction by co-targeting the MAPK pathway and mitochondrial Hsp90-directed protein folding with specific inhibitors prevented entry of cells into a reversibly senescent state, suppressed mitochondrial energy metabolism and augmented therapy response.
Targeting mitochondrial biogenesis to overcome drug resistance to MAPK inhibitors.
Disease, Disease stage, Cell line, Time
View SamplesThe human and mouse aryl hydrocarbon receptor (hAHR and mAHRb) share limited (58%) transactivation domain sequence identity. Compared to the mAHRb allele, the hAHR displays 10-fold lower relative affinity for prototypical ligands such as 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD). However, in previous studies we have demonstrated that the hAHR can display a higher relative ligand binding affinity than the mAHRb for specific AHR ligands such as indirubin. Each receptor has also been shown to differentially recruit LXXLL co-activator-motif proteins and to utilize different TAD subdomains in gene transactivation. Using hepatocytes isolated from C57BL6/J mice (Ahrb/b) and AHRTtr transgenic mice which express hAHR protein specifically in hepatocytes, we investigated whether the hAHR and mAHRb differentially regulate genes. Microarray and quantitative-PCR analysis of Ahrb/b and AHRTtr primary-mouse hepatocytes treated with 10 nM TCDD revealed that a number of established AHR target genes such as Cyp1a1 and Cyp1b1 are significantly induced by both receptors. Remarkably, of the 1752 genes induced by mAHRb and 1186 genes induced by hAHR, only 265 genes (<10%) were significantly activated by both receptors in response to TCDD. Conversely of the 1100 and 779 genes significantly repressed in mAHRb and hAHR hepatocytes respectively, only 462 (<25%) genes were significantly repressed by both receptors in response to TCDD treatment. Genes identified as differentially expressed are known to be involved in a number of biological pathways, including cell proliferation and inflammatory response which suggests that compared to the mAHRb, the hAHR may play contrasting roles in TCDD-induced toxicity and endogenous AHR-mediated gene regulation.
Differential gene regulation by the human and mouse aryl hydrocarbon receptor.
Specimen part
View SamplesCD4+ and CD8+ T cells isolated from wild-type and Foxo1-deficient mice were analyzed by global gene expression profiling with Affymetrix array MOE 430 2.0. Results indicate Foxo1 regulates the expression of genes encoding positive regulators of T cell activation, differentiation, homeostasis, cell adhesion, cell migration, and cellular stress responses.
An essential role of the Forkhead-box transcription factor Foxo1 in control of T cell homeostasis and tolerance.
Specimen part
View SamplesWe found that Hopx is required for the function of DC-induced regulatory T cells in vivo. We used microarrays to identify relevant Hopx-targets in such cells after antigenic re-challenge in vivo.
The transcription cofactor Hopx is required for regulatory T cell function in dendritic cell-mediated peripheral T cell unresponsiveness.
Specimen part
View SamplesForeign body reaction (FBR), initiated by adherence of macrophages to biomaterials, is associated with several complications.
Gene expression study of monocytes/macrophages during early foreign body reaction and identification of potential precursors of myofibroblasts.
Specimen part
View Samples