The maintenance of advanced malignancies relies on continued activity of driver oncogenes, although their rate-limiting role is highly context-dependent with respect to tumor types and associated genetic alterations. Oncogenic Kras mutation is the signature event in human pancreatic ductal adenocarcinoma (PDAC), serving a critical role in tumor initiation. Here, an inducible KrasG12D-driven p53 mutant PDAC mouse model establishes that advanced PDAC remains strictly dependent on continued KrasG12D expression and that KrasG12D serves a vital role in the control of tumor metabolism, through stimulation of glucose uptake and channeling of glucose intermediates through the hexosamine biosynthesis pathway (HBP) and the pentose phosphate pathway (PPP). Notably, these studies reveal that oncogenic Kras regulates ribose biogenesis. Unlike canonical models of PPP-mediated ribose biogenesis, we demonstrate that oncogenic Kras drives intermediates from enhanced glycolytic flux into the non-oxidative arm of the PPP, thereby decoupling ribose biogenesis from NADPNADPH-mediated redox control. Together, this work provides in vivo mechanistic insights into how oncogenic Kras promotes metabolic reprogramming in native tumors and illuminates potential metabolic targets that can be exploited for therapeutic benefit in Kras-driven PDAC.
Oncogenic Kras maintains pancreatic tumors through regulation of anabolic glucose metabolism.
Specimen part, Treatment
View SamplesIn this dataset, we include the expression data obtained from KRas expressing tumors, matched Kras expressing tumor spheres, surviving cells and surviving cells after KRas re-expression for 24hs
Oncogene ablation-resistant pancreatic cancer cells depend on mitochondrial function.
Specimen part
View SamplesThe objective of this study was to understand the genetic mechanisms of Vitamin-A-Deficiency (VAD)-induced arrest of spermatogonial stem-cell differentiation. Vitamin A and its derivatives (the retinoids) participate in many physiological processes including vision, cellular differentiation and reproduction. VAD affects spermatogenesis, the subject of our present study. Spermatogenesis is a highly regulated process of differentiation and complex morphologic alterations that, in the postnatal testis, leads to the formation of sperm in the seminiferous epithelium. VAD causes early cessation of spermatogenesis, characterized by degeneration of meiotic germ cells, leading to seminiferous tubules containing mostly type A spermatogonia and Sertoli cells. In this study, we investigated the molecular basis of VAD on spermatogenesis in mice. We used adult Balb/C mice fed with a Control or VAD diet for an extended period of time (8-28 weeks) and selected two time points (18 and 25 weeks) for microarray analysis.
Long-term vitamin A deficiency induces alteration of adult mouse spermatogenesis and spermatogonial differentiation: direct effect on spermatogonial gene expression and indirect effects via somatic cells.
Specimen part, Treatment
View SamplesThe present study reports an unbiased analysis of the cytotoxic T cell serine-threonine phosphoproteome using high resolution mass spectrometry. Approximately 2,000 phosphorylations were identified in CTLs of which approximately 450 were controlled by TCR signaling. A significantly overrepresented group of molecules identified in the phosphoproteomic screen were transcription activators, co-repressors and chromatin regulators. A focus on the chromatin regulators revealed that CTLs have high expression of the histone deacetylase HDAC7 but continually phosphorylate and export this transcriptional repressor from the nucleus. HDAC7 dephosphorylation results in its nuclear accumulation and suppressed expression of genes encoding key cytokines, cytokine receptors and adhesion molecules that determine CTL function. The screening of the CTL phosphoproteome thus reveals intrinsic pathways of serine-threonine phosphorylation that target chromatin regulators in CTLs and determine the CTL functional program. We used Affymetrix microarray analysis to explore the molecular basis for the role of HDAC7 in CTLs and the impact of GFP-HDAC7 phosphorylation deficient mutant expression on the CTL transcriptional profile.
Phosphoproteomic analysis reveals an intrinsic pathway for the regulation of histone deacetylase 7 that controls the function of cytotoxic T lymphocytes.
Specimen part
View SamplesOn triggering of the T cell receptor CD8 T lymphocytes downregulate expression of the transcription factor KLF2. KLF2 expression remains low as these cells differentiate to Cytotoxic T lymphocytes (CTL) but may be re-expressed depending on the local environmental signals.
The impact of KLF2 modulation on the transcriptional program and function of CD8 T cells.
Specimen part
View SamplesThe mechanisms involved in epithelium-stroma interactions remain poorly understood, despite the importance of the microenvironment during tumorigenesis. Here, we studied the role of Ets2 transcrpiton factor in tumor associated fibroblasts in the MMTV-ErbB2 mammary tumor model. Inactivation of Ets2 specifically in fibroblasts using Fsp-cre significantly reduced tumor growth, in contrast to Ets2 inactivation in epithelium in which no differences in tumor growth were observed.
Ets2 in tumor fibroblasts promotes angiogenesis in breast cancer.
Age, Specimen part
View SamplesSV40 large T antigen (TAg) contributes to cell transformation, in part, by targeting two well characterized tumor suppressors, pRb and p53. TAg expression affects the transcriptional circuits controlled by Rb and by p53. We have performed a microarray analysis to examine the global change in gene expression induced by wild-type TAg and TAg-mutants, in an effort to link changes in gene expression to specific transforming functions. For this analysis we have used enterocytes from the mouse small intestine expressing TAg. Expression of TAg in the mouse intestine results in hyperplasia and dysplasia. Our analysis indicates that practically all gene expression regulated by TAg in enterocytes is dependent upon its binding and inactivation of the Rb-family proteins.
Simian virus 40 T-antigen-mediated gene regulation in enterocytes is controlled primarily by the Rb-E2F pathway.
Sex, Age, Specimen part
View SamplesIn cytotoxic T cells (CTL), Protein Kinase B /Akt is activated by the T cell antigen receptor (TCR) and the cytokine Interleukin 2 (IL2), in part by phosophorylation of Akt by Phospholipid dependent kinase 1 (PDK1).
Protein kinase B controls transcriptional programs that direct cytotoxic T cell fate but is dispensable for T cell metabolism.
Specimen part
View SamplesComparison of transcriptional profile of CD8 cytotoxic T lymphocytes terated with the mTORC1 inhibitor rapamycin or the mTOR inhibitor KU-0063794 and comparison with proteomic analysis.
The cytotoxic T cell proteome and its shaping by the kinase mTOR.
Specimen part, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Human fetal hemoglobin expression is regulated by the developmental stage-specific repressor BCL11A.
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