Resistance to tamoxifen in breast cancer patients is a serious therapeutic problem and major efforts are underway to understand underlying mechanisms. Resistance can be either intrinsic or acquired. We derived a series of subcloned MCF7 cell lines that were either highly sensitive or naturally resistant to tamoxifen and studied the factors that lead to drug resistance. Gene-expression studies revealed a signature of 67 genes that differentially respond to tamoxifen in sensitive vs. resistant subclones, which also predicts disease-free survival in tamoxifen-treated patients. High-throughput cell-based screens, in which >500 human kinases were independently ectopically expressed, identified 31 kinases that conferred drug resistance on sensitive cells. One of these, HSPB8, was also in the expression signature and, by itself, predicted poor clinical outcome in one cohort of patients. Further studies revealed that HSPB8 protected MCF7 cells from tamoxifen and blocked autophagy. Moreover, silencing HSBP8 induced autophagy and caused cell death. Tamoxifen itself induced autophagy in sensitive cells but not in resistant ones, and tamoxifen-resistant cells were sensitive to the induction of autophagy by other drugs. These results may point to an important role for autophagy in the sensitivity to tamoxifen.
High-throughput ectopic expression screen for tamoxifen resistance identifies an atypical kinase that blocks autophagy.
Specimen part, Cell line
View SamplesRecently a new neonatal diabetes syndrome, Mitchell-Riley syndrome, was discovered. To identify the genetic cause of the syndrome homozygosity mapping was used, several chromosomal regions were linked to Mitchell-Riley syndrome. In situ hybridization of genes from one such region using model organism Xenopus laevis identified RFX6 as a potential candidate gene; mutant forms of RFX6 were subsequently found in Mitchell-Riley patients. Analysis of the expression pattern of RFX6 in Xenopus development shows it is expressed broadly in the endoderm early in development, and later RFX6 becomes restricted to the endocrine cells of the gut and pancreas. Morpholino knockdown of RFX6 in Xenopus caused a loss of pancreas marker gene expression. Injection of exogenous wild type RFX6 rescued the morpholino phenotype in Xenopus tadpoles. Attempts to rescue the loss-of-function phenotype using mutant forms of RFX6 found in Mitchell-Riley patients were unsuccessful suggesting the changes lead to loss-of-function and could be the cause of Mitchell-Riley syndrome. Microarray analysis of gene expression in knockdown tissue suggested a downregulation in marker genes for lung, stomach and heart, ambiguous results for the liver, and an upregulation in kidney marker gene expression. RT-PCR and in situ hybridization confirms a loss of lung, stomach and heart gene expression, no change in liver marker hex and an upregulation in kidney marker KcnJ1. The fact that the morpholino phenotype affects multiple organs suggests that RFX6 has a broad role early in endoderm development.
Functional analysis of Rfx6 and mutant variants associated with neonatal diabetes.
Specimen part, Treatment
View SamplesSystemic administration of -adrenoceptor (-AR) agonists has been found to induce skeletal muscle hypertrophy and significant metabolic changes. In the context of energy homeostasis, the importance of -AR signaling has been highlighted by the inability of 13-AR-deficient mice to regulate energy expenditure and susceptibility to diet induced obesity. However, the molecular pathways and gene expression changes that initiate and maintain these phenotypic modulations are poorly understood. Therefore, the aim of this study was to identify differential changes in gene expression in murine skeletal muscle associated with systemic acute administration of the 2-AR agonist formoterol. Skeletal muscle gene expression (from murine tibialis anterior) was profiled at both 1 and 4 hours following systemic administration of the 2-AR agonist formoterol, using 46K Illumina(R) Sentrix BeadArrays. Illumina expression profiling revealed significant expression changes in genes associated with skeletal muscle hypertrophy, myoblast differentiation, metabolism, circadian rhythm, transcription, histones, and oxidative stress.
Expression profiling of skeletal muscle following acute and chronic beta2-adrenergic stimulation: implications for hypertrophy, metabolism and circadian rhythm.
Treatment
View SamplesEpimorphic regeneration is the process by which complete regeneration of a complex structure such as a limb occurs through production of a proliferating blastema. This type of regeneration is rare among vertebrates but does occur in the African clawed frog Xenopus laevis, traditionally a model organism for the study of early development. Xenopus tadpoles can regenerate tails, limb buds and the lens of the eye, although the ability of the latter two organs to regenerate diminishes with advancing developmental stage. Using a heat shock inducible transgene that remains silent unless activated, we have established a stable line of transgenic Xenopus in which the BMP inhibitor Noggin can be over-expressed at any time during development. We have previously shown that activation of this transgene blocks regeneration of the tail and limb of Xenopus tadpoles. In the current study, we have taken advantage of this transgenic line to directly compare gene expression in same stage regenerating vs. non-regenerating hind limb buds. Using Affymetrix gene chip analysis, we have identified genes whose expression levels are linked to regenerative success. These include the BMP inhibitor Gremlin and the stress protein Hsp60 (no blastema in zebrafish). Analysis of overrepresented Gene Ontology functional groupings suggests that successful regeneration in the Xenopus hind limb depends on induction of stress response pathways. Furthermore, as expected, genes involved in embryonic development and growth are also significantly over-represented in regenerating early hind limb buds.
Identification of genes associated with regenerative success of Xenopus laevis hindlimbs.
No sample metadata fields
View SamplesA distinct highly invasive subpopulation was identified in breast cancer cell lines. The molecular characteristics of these cells was investigated, revealing a set of genes whose high expression confers the ability to invade.
ΔNp63α Promotes Breast Cancer Cell Motility through the Selective Activation of Components of the Epithelial-to-Mesenchymal Transition Program.
Cell line
View SamplesMicroRNAs (miRNAs) are important regulators and potential therapeutic targets of metabolic disease. In this study we show by in vivo administration of locked nucleic acid (LNA) inhibitors that suppression of endogenous miR-29 lowers plasma cholesterol levels by ~40%, commensurate with the effect of statins, and reduces fatty acid content in the liver by ~20%. Whole transcriptome sequencing of the liver reveals 883 genes dysregulated (612 down, 271 up) by inhibition of miR-29. The set of 612 down-regulated genes are most significantly over-represented in lipid synthesis pathways. Among the up-regulated genes are the anti-lipogenic deacetylase sirtuin 1 (Sirt1) and the anti-lipogenic transcription factor aryl hydrocarbon receptor (Ahr), the latter of which we demonstrate is a direct target of miR-29. In vitro radiolabeled acetate incorporation assays confirm that pharmacologic inhibition of miR-29 significantly reduces de novo cholesterol and fatty acid synthesis. Our findings indicate that miR-29 controls hepatic lipogenic programs, likely in part through regulation of Ahr and Sirt1, and therefore may represent a candidate therapeutic target for metabolic disorders such as dyslipidemia. Overall design: Hepatic mRNA profiles of C57BL/6J female mice treated with LNA against miR-29a, miR-29b and miR-29c versus saline.
Inhibition of miR-29 has a significant lipid-lowering benefit through suppression of lipogenic programs in liver.
No sample metadata fields
View SamplesCarcinoma-associated mesenchymal stem cells (CA-MSCs) are critical stromal progenitor cells within the tumor microenvironment. We previously demonstrated that CA-MSCs differentially express BMP genes, promote tumor cell growth, increase cancer 'stemness' and chemotherapy resistance. Here we use RNA sequencing of normal omental MSCs and ovarian CA-MSCs to demonstrate CA-MSCs have global changes in gene expression. Using these expression profiles we create a unique predictive algorithm to classify CA-MSCs. Our classifier, accurately distinguishes normal omental, ovary and bone marrow MSCs from ovarian cancer CA-MSCs. Suggesting broad applicability, the model correctly classifies pancreatic and endometrial cancer CA-MSCs and distinguishes cancer associated fibroblasts (CAFs) from CA-MSCs. Using this classifier, we definitively demonstrate ovarian CA-MSCs arise from tumor mediated reprograming of local tissue MSCs. While cancer cells alone cannot induce a CA-MSC phenotype, the in vivo ovarian tumor micoenvironment (TME) can reprogram omental or ovary MSCs to protumorigenic CA-MSC (classifier score of >0.96). In vitro studies suggest that both tumor secreted factors and hypoxia are critical to induce the CA-MSC phenotype. Interestingly, while the breast cancer TME can reprogram BM MSCs into CA-MSCs, the ovarian TME cannot, demonstrating for the first time that tumor mediated CA-MSC conversion is tissue and cancer type dependent. Together these findings (1) provide a critical tool to define CA-MSCs and (2) highlight cancer cell influence on distinct normal tissues providing powerful insights into the mechanisms underlying cancer specific metastatic niche formation. Carcinoma-associated mesenchymal stem cells (CA-MSCs) are critical stromal progenitor cells within the tumor microenvironment. We previously demonstrated that CA-MSCs differentially express BMP genes, promote tumor cell growth, increase cancer 'stemness' and chemotherapy resistance. Here we use RNA sequencing of normal omental MSCs and ovarian CA-MSCs to demonstrate CA-MSCs have global changes in gene expression. Using these expression profiles we create a unique predictive algorithm to classify CA-MSCs. Our classifier, accurately distinguishes normal omental, ovary and bone marrow MSCs from ovarian cancer CA-MSCs. Suggesting broad applicability, the model correctly classifies pancreatic and endometrial cancer CA-MSCs and distinguishes cancer associated fibroblasts (CAFs) from CA-MSCs. Using this classifier, we definitively demonstrate ovarian CA-MSCs arise from tumor mediated reprograming of local tissue MSCs. While cancer cells alone cannot induce a CA-MSC phenotype, the in vivo ovarian tumor micoenvironment (TME) can reprogram omental or ovary MSCs to protumorigenic CA-MSC (classifier score of >0.96). In vitro studies suggest that both tumor secreted factors and hypoxia are critical to induce the CA-MSC phenotype. Interestingly, while the breast cancer TME can reprogram BM MSCs into CA-MSCs, the ovarian TME cannot, demonstrating for the first time that tumor mediated CA-MSC conversion is tissue and cancer type dependent. Together these findings (1) provide a critical tool to define CA-MSCs and (2) highlight cancer cell influence on distinct normal tissues providing powerful insights into the mechanisms underlying cancer specific metastatic niche formation. Overall design: mRNA profiles of 4 normal omental MSCs and 10 ovarian CA-MSCs using Illumina TruSeq RNA Sample Preparation kit and Illumina HiSeq 100bp PE sequencing.
Ovarian Carcinoma-Associated Mesenchymal Stem Cells Arise from Tissue-Specific Normal Stroma.
Specimen part, Subject
View SamplesUsing RNA sequencing (Illumina Hi-Seq 2000 sequencer) we report the transcriptome profile of primary human chondrocytes isolated from patients with hip osteoarthritis (OA), and the transcriptome response of these cells to 4h stimulation with IL-1ß (1ng/ml). In total, 983 long non-coding RNAs (lncRNAs) were identified, which included 642 intergenic lncRNAs (lincRNAs), 124 antisense and pseudogenes. Less than 4% of the identified lncRNAs overlapped with putative eRNAs regions, and visual inspection showed that they were uni-directional and multi-exonic. Upon IL-1ß stimulation 499 protein-coding genes were differentially expressed, and 158 lncRNAs were differentially expressed, including 92 lincRNAs, 13 antisense and 18 psudogenes. This study demonstrates that IL-1ß induces a rapid and widespread change in the transcriptome of the primary human OA chondrocyte. Overall design: RNA sequencing analysis of primary human chondrocytes isolated from n=3 patients with hip osteoarthritis, with and without 4h IL-1b (1ng/ml) stimulation
Long Intergenic Noncoding RNAs Mediate the Human Chondrocyte Inflammatory Response and Are Differentially Expressed in Osteoarthritis Cartilage.
No sample metadata fields
View SamplesProlonged cold exposure stimulates the recruitment of beige adipocytes within white adipose tissue. Beige adipocytes depend on mitochondrial oxidative phosphorylation to drive thermogenesis. The transcriptional coregulator TLE3 inhibits mitochondrial and metabolic gene expression in beige adipocytes. Overall design: mRNA profiles of iWAT immortalized preadipocytes, differentiated in culture, and knocking out TLE3 after differentiation, were generated by deep sequencing, in triplicate, using Illumina HiSeq 2500.
Loss of TLE3 promotes the mitochondrial program in beige adipocytes and improves glucose metabolism.
Specimen part, Treatment, Subject
View SamplesMacrophages polarize to divergent functional phenotypes depending on their microenvironment in a highly coordinated process of metabolic and transcriptional rewiring that is still poorly understood. We developed an Integrated Metabolomics and Gene Expression (IMAGE) profiling and analysis pipeline and applied it to extensively characterize global metabolic programs of macrophage polarization. IMAGE analysis identified 7 major (novel and known) regulatory modules responsible for metabolic rewiring during polarization, which we validated through extensive carbon and nitrogen labeling experiments. M1-specific modules included: inflammatory variant of the aspartate-arginosuccinate shunt; TCA cycle break at Idh expression accompanied by citrate accumulation and production of itaconate and fatty acid synthesis. In M2 macrophages we discovered significant role of glutamine in polarization, providing nitrogen for UDP-GlcNAc synthesis. Consistently, glutamine deprivation results in significant M2-specific defect in polarization. Our data provide, for the first time, a global view of the integrated transcriptional and metabolic changes that result in M1 and M2 polarization. Overall design: Bone-marrow derived macrophages were generated from C57BL/6 mice were plated at ~100k cells per well in 96-well plate and stimulated with either Il4 or combination of LPS&IFNg or left unstimulated for 24 h mRNA was derived from lysates using Invitrogen oligo-dT beads
Cell-intrinsic lysosomal lipolysis is essential for alternative activation of macrophages.
No sample metadata fields
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