Expression of insulin in terminally differentiated non-beta pancreatic cell types could be important for treating type-1 diabetes. We observed that the kinase inhibitor GW8510 up-regulated insulin expression in mouse pancreatic alpha cells.
GW8510 increases insulin expression in pancreatic alpha cells through activation of p53 transcriptional activity.
Cell line, Compound
View SamplesReduction in the cellular levels of the cyclin kinase inhibitor p27kip1 are frequently found in many human cancers and correlate directly with patient prognosis. Specifically ubiquitin dependent proteasomal turnover has been shown to cause reduced p27 expression in many human cancers. We recently demonstated that expression of a stabilized version of p27kip1 (p27kip1T187A) in a genetically modified mouse significantly reduced the number of intestinal adenomatous polyps which progressed to invasive carcinomas. Based on this work we set out to identify compounds which lead to a re-expression of p27 in cancer tissues. In this work we identify Argyrin A a compound derived from myxobacterium archangium gephyra as a potent inducer of p27kip1 expression. Argyrin A induces apoptosis in human colon cancer xenografts and tumor vasculature in vivo leading to a profound reduction in tumor size at well tolerated levels. Argyrin A functions are strictly dependent on the expression of p27kip1 as neither tumor cells nor endothelial cells which do not express p27kip1 respond to this compound. Surprisingly the molecular mechanism by which Argyrin A exerts its p27 dependent biological function is through a potent inhibition of the 20S proteasome.
Argyrin a reveals a critical role for the tumor suppressor protein p27(kip1) in mediating antitumor activities in response to proteasome inhibition.
Specimen part
View SamplesResistance formation is one of the major hurdles in cancer therapy. Metronomic anti-angiogenic treatment of xenografted prostate cancer tumors in SCID mice with cyclophosphamide (CPA) results in the appearance of resistant tumors. To investigate the complex molecular changes occurring during resistance formation, we performed a comprehensive gene expression analysis of the resistant tumors in vivo. We observed a multitude of differentially expressed genes, e.g., PASD1, ANXA3, NTS or PLAT, when comparing resistant to in vivo passaged tumor samples. Furthermore, tumor cells from in vivo and in vitro conditions showed a significant difference in target gene expression. We assigned the differentially expressed genes to functional pathways like axon guidance, steroid biosynthesis and complement and coagulation cascades. Most of the genes were involved in anti-coagulation, indicating its possible importance. Upregulation of anti-coagulatory ANXA3 and PLAT and downregulation of PLAT inhibitor SERPINA were validated by qPCR. In contrast, coagulation factor F3 was upregulated, accompanied by the expression of an altered gene product. These findings give insights into the resistance mechanisms of metronomical CPA treatment suggesting an important role of anti-coagulation in resistance formation.
A Comprehensive Gene Expression Analysis of Resistance Formation upon Metronomic Cyclophosphamide Therapy.
Specimen part, Cell line, Treatment
View SamplesWe measured the genome-wide expression changes induced by 29 compounds targeting HDACs, DNMTs, histone lysine methyltransferases (HKMTs), and protein arginine methyltransferases (PRMTs) in pancreatic - and -cell lines.
Chromatin-targeting small molecules cause class-specific transcriptional changes in pancreatic endocrine cells.
Cell line, Treatment
View SamplesMale Wistar rats weighing 90-120 g were acclimatized for one week and fed standard laboratory chow, at which time the animals were divided into two groups. Animals were then pair-fed for 8 weeks a regular laboratory chow and water ad libitum or Lieber-DeCarli diet (36% calories from ethanol). Control animals received the iso-caloric amount of dextrose to replace ethanol. After 8 weeks of differential feeding rats were euthanized, the pancreas immediately dissected and stored at -80?C until RNA isolation. RNA expression was analyzed using Affymetrix RAE230A gene chips
Long-term ethanol consumption alters pancreatic gene expression in rats: a possible connection to pancreatic injury.
No sample metadata fields
View SamplesBreast cancer is genetically heterogeneous, and recent studies have underlined a prominent contribution of epigenetics to the development of this disease. To uncover new synthetic lethalities with known breast cancer oncogenes, we screened an epigenome-focused short hairpin RNA library on a panel of engineered breast epithelial cell lines. Here we report a selective interaction between the NOTCH1 signaling pathway and the SUMOylation cascade. Knockdown of the E2-conjugating enzyme UBC9 (UBE2I) as well as inhibition of the E1-activating complex SAE1/UBA2 using ginkgolic acid impairs the growth of NOTCH1-activated breast epithelial cells. We show that upon inhibition of SUMOylation NOTCH1-activated cells proceed slower through the cell cycle and ultimately enter apoptosis. Mechanistically, activation of NOTCH1 signaling depletes the pool of unconjugated small ubiquitin-like modifier 1 (SUMO1) and SUMO2/3 leading to increased sensitivity to perturbation of the SUMOylation cascade. Depletion of unconjugated SUMO correlates with sensitivity to inhibition of SUMOylation also in patient-derived breast cancer cell lines with constitutive NOTCH pathway activation. Our investigation suggests that SUMOylation cascade inhibitors should be further explored as targeted treatment for NOTCH-driven breast cancer. Overall design: We treated MCF10A and NOTCH1 cells with either DMSO or ginkgolic acid 30 uM for 3 days. Two replicates have been analysed for each condition.
NOTCH1 activation in breast cancer confers sensitivity to inhibition of SUMOylation.
No sample metadata fields
View SamplesAberrations in genes coding for subunits of the BAF chromatin remodeling complex are highly abundant in human cancers. Currently, it is not understood how these loss-of-function mutations contribute to cancer development and how they can be targeted therapeutically. The cancer type specific occurrence patterns of certain subunit mutations suggest subunit-specific effects on BAF complex function, possibly by the formation of aberrant residual complexes. Here, we systematically characterize the effects of individual subunit loss on complex composition, chromatin accessibility and gene expression in a panel of knock-out cell lines deficient for 22 targetable BAF subunits. We observe strong, specific and often discordant alterations dependent on the targeted subunit and show that these explain intra-complex co-dependencies, including the novel synthetic lethal interactions SMARCA4-ARID2, SMARCA4-ACTB and SMARCC1-SMARCC2. These data provide insights into the role of different BAF subcomplexes in genome-wide chromatin organization and suggest novel approaches to therapeutically target BAF mutant cancers. Overall design: RNA-seq samples for knockouts of BAF complex in the HAP1 cell line.
Systematic characterization of BAF mutations provides insights into intracomplex synthetic lethalities in human cancers.
Cell line, Subject
View SamplesSW480 cells were treated with 2uM crizotinib for 72h (versus DMSO) Overall design: Examination of differential up- or down-regulated genes after crizotinib treatment
Global survey of the immunomodulatory potential of common drugs.
Cell line, Subject
View SamplesA basal (MDAMB468) and luminal (ZR75-1) cell line were treated with DMSO or PKC412 for 6h Overall design: 2 DMSO and 3 PKC412 treated samples for each cell line
Targeting a cell state common to triple-negative breast cancers.
No sample metadata fields
View SamplesCommon and distinct transcriptomic responses to moderate light and drought stress in the different mutants.
Decreasing electron flux through the cytochrome and/or alternative respiratory pathways triggers common and distinct cellular responses dependent on growth conditions.
Specimen part
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