Choline kinase alpha (CHKA) plays a crucial role in the regulation of membrane phospholipid synthesis and has oncogenic properties in vitro. We have analyzed the expression of CHKA in cell lines derived from pancreatic ductal adenocarcinoma (PDAC) and have found increased CHKA expression and a good correlation between protein expression and sensitivity to MN58b, a CHKA inhibitor that reduced cell growth through the induction of apoptosis. Accordingly, CHKA knockdown led to reduced drug sensitivity. In addition, we found that gemcitabine-resistant PDAC cells displayed enhanced sensitivity to CHKA inhibition and, in vitro, MN58b had synergistic effects with gemcitabine, 5-fluorouracil and oxaliplatin, three active drugs in the treatment of PDAC. Using tissue microarrays, CHKA was found to be overexpressed in 90% of pancreatic tumors. While cytoplasmic CHKA did not relate to survival, nuclear CHKA distribution was observed in 43% of samples and was associated with survival, especially among patients with well/moderately differentiated tumors. To identify the mechanisms involved in resistance to CHKA inhibitors, we cultured IMIM-PC-2 cells with continuous incremental concentrations of MN58b and isolated a subline with a 30-fold higher IC50. RNA-Seq analysis identified up-regulation of ABCB1 and ABCB4 multidrug resistance transporters and functional studies confirmed that their up-regulation is the main mechanism involved in resistance. Overall, our findings support the notion that CHKA inhibition merits further attention as a therapeutic option in patients with PDAC. Overall design: RNA profile from parental and MN58b-resistant IMIM-PC-2 were generated by deep sequencing were done in triplicates using illumina GAIIx
Choline Kinase Alpha (CHKα) as a Therapeutic Target in Pancreatic Ductal Adenocarcinoma: Expression, Predictive Value, and Sensitivity to Inhibitors.
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View SamplesCholine kinase a (CHKa) plays a crucial role in the regulation of membrane phospholipid synthesis and has oncogenic properties in vitro. We have analyzed the expression of CHKa in cell lines derived from pancreatic ductal adenocarcinoma (PDAC) and have found increased CHKa expression, associated with differentiation. CHKa protein expression was directly correlated with sensitivity to MN58b, a CHKa inhibitor that reduced cell growth through the induction of apoptosis. Accordingly, CHKa knockdown led to reduced drug sensitivity. In addition, we found that gemcitabine-resistant PDAC cells displayed enhanced sensitivity to CHKa inhibition and, in vitro, MN58b had additive or synergistic effects with gemcitabine, 5-fluorouracil, and oxaliplatin, three active drugs in the treatment of PDAC. Using tissue microarrays, CHKa was found to be overexpressed in 90% of pancreatic tumors. While cytoplasmic CHKa did not relate to survival, nuclear CHKa distribution was observed in 43% of samples and was associated with longer survival, especially among patients with well/moderately differentiated tumors. To identify the mechanisms involved in resistance to CHKa inhibitors, we cultured IMIM-PC-2 cells with increasingly higher concentrations of MN58b and isolated a subline with a 30-fold higher IC50. RNA-Seq analysis identified upregulation of ABCB1 and ABCB4 multidrug resistance transporters, and functional studies confirmed that their upregulation is the main mechanism involved in resistance. Overall, our findings support the notion that CHKa inhibition merits further attention as a therapeutic option in patients with PDAC and that expression levels may predict response. Overall design: RNAseq from parental (IMIM-PC2 cell line)) and MN58b-resistant cells by triplicate
Choline Kinase Alpha (CHKα) as a Therapeutic Target in Pancreatic Ductal Adenocarcinoma: Expression, Predictive Value, and Sensitivity to Inhibitors.
Sex, Specimen part, Cell line, Subject
View SamplesMultipotent pancreatic progenitors (MPC) are defined as Ptf1a+, Mychigh, Cpa+ cells. During the transition from MPC to unipotent acinar progenitors, c-Myc is down-regulated whereas Ptf1a is up-regulated, leading to the deployment of the acinar program. Here, we show that c-Myc and Ptf1a interact directly and c-Myc binds to, and represses, the transcriptional activity of the PTF1 complex in vitro and in vivo. Using Ela1-Myc mice, in which c-Myc is overexpressed in acinar cells starting at E14.5, we find that acinar cells fail to undergo normal maturation at P1 and this is followed by a massive subsequent repression of the acinar programme. Lineage tracing with Ptf1aCreERT2;Rosa26YFP and Ela1-Myc;Ptf1aCreERT2;Rosa26YFP mice receiving TMX at E15.5 and analyzed at E18.5 revealed that c-Myc overexpression is associated with activation of a hepatic programme but not with pancreatic lineage misspecification At 8 weeks, the silencing of the acinar program is associated with increased expression of the PRC2 complex in a c-Myc dependent manner. Genome wide studies show that Ptf1a and c-Myc display partially overlapping chromatin occupancy patterns and DNA binding competition. We conclude that c-Myc down-regulation during development is crucial for the maturation of pre-acinar to acinar cells. c-Myc overexpression may contribute to pancreatic carcinogenesis by restraining cell differentiation and rendering cells susceptible to transformation. Overall design: Pancreas mRNA profiles of 8-week old wild type (WT) and ELA1-MYC mice were generated by deep sequencing, in triplicate, using Illumina GAIIx.
c-Myc downregulation is required for preacinar to acinar maturation and pancreatic homeostasis.
Age, Specimen part, Subject
View SamplesPurpose: Asess the transcritpional changes induced upon RAB7 knock-down in melanoma (SK-Mel-28 and UACC-62) and in colon cancer (HCT-116) cell lines. Methods: mRNA profiles of tumor cell lines (SK-Mel-28, UACC-62, HCT-116) stably expressing scrambled shRNA or RAB7 shRNA (harvested at day 3 after lentiviral infection) were generated by deep sequencing, using three biological replicates per condition. The sequence reads that passed quality filters were analyzed with TopHat and Cufflinks. Validation of induced / silenced genes was performed by western blot. Results show a differential impact of RAB7 expression in the transcriptomic profile of melanoma vs non-melanoma cell lines, and support a lineage-specific role of this small GTPase in melanoma. Overall design: Examination of the mRNA profiles RAB7-depleted vs wild type cells, performed in parallel in 3 different tumor cell lines (Melanomas: SK-Mel-28 and UACC-62, Non-melanoma: HCT-116) harvested at day 3 after lentiviral infection.
RAB7 controls melanoma progression by exploiting a lineage-specific wiring of the endolysosomal pathway.
Cell line, Treatment, Subject, Time
View SamplesTissue-specific differentiation and inflammatory programmes are thought to independently contribute to disease. The orphan nuclear receptor NR5A2 is a key regulator of pancreas differentiation, and SNPs in and near the human gene are associated with risk of pancreatic cancer. In mice, Nr5a2 heterozygosity sensitizes the pancreas to damage, impairs regeneration, and cooperates with mutant Kras in tumor progression. Through transcriptomic analysis, we uncovered a basal pre-inflammatory state in the pancreas of heterozygous mice that is reminiscent of pancreatitis-induced inflammation and is conserved in histologically normal human pancreata with reduced Nr5a2 mRNA expression. In mice, Nr5a2 undergoes a dramatic transcriptional switch from tissue-specific to inflammatory loci, which promotes AP-1-dependent inflammatory gene transcription. Deletion of c-Jun in the pancreas of Nr5a2+/- mice rescues the pre-inflammatory phenotype and the defective regenerative response to damage. These findings provide compelling evidence that the same transcriptional networks supporting homeostasis in normal tissue can be subverted to foster inflammation upon genetic or environmental constraints. Overall design: A mild acute pancreatitis was induced by seven hourly injections of the CCK analog caerulein (Bachem) at 50 ug/kg. Briefly, animals were weighted before the beginning of the procedure and caerulein was administered i.p. Mice were sacrificed by cervical dislocation 8h, 24h,and 48h after the first injection. Three animals of each genotype and timepoint were analysed.
Transcriptional regulation by NR5A2 links differentiation and inflammation in the pancreas.
Specimen part, Treatment, Subject
View SamplesDepolarization of resting membrane potential in select cells in Xenopus larvae induces striking hyperpigmentation due to dysregulation of melanocytes. Here, we show that this non-cell-autonomous process is mediated by cAMP, CREB, and the transcription factors Sox10 and Slug. Our microarray analysis reveals specific transcripts responsive to Vmem levels within a few hours of depolarization, and a set of 517 transcripts whose expression remains altered during the full hyperpigmented phenotype over a week later, linking instructor cell-depolarization to a range of developmental processes and disease states. We also show that voltage-dependent conversion of melanocytes involves the MSH-secreting melanotrope cells of the pituitary, and formulate a model for the molecular pathway linking the bioelectric properties of melanocyte cells microenvironment in vivo to the genetic and cellular changes induced in this melanoma-like phenotype. Remarkably, the phenotype is all-or-none: each individual animal either undergoes melanocyte conversion or not, as a whole. This group decision is stochastic, resulting in varying percentages of hyperpigmented individuals for a given experimental treatment. To understand the stochasticity and dynamic properties of this complex signaling system, we developed a novel computational method that automates the reverse-engineering of stochastic dynamic signaling models. We used this method to discover a network model that quantitatively explained our complex dataset, and even made correct predictions for new experiments that we validated in vivo. Taken together, these data (1) reveal new molecular details about a novel trigger of metastatic-like developmental cell behavior in vivo, (2) suggest new targets for biomedical intervention, and (3) demonstrate proof-of-principle of a computational method for understanding stochastic decision-making by cells during embryonic development and metastasis.
Serotonergic regulation of melanocyte conversion: A bioelectrically regulated network for stochastic all-or-none hyperpigmentation.
Specimen part
View SamplesBackground. Although the emergence of RNA sequencing (RNA-seq), microarrays remain in widespread use for gene expression analysis in the clinic. There are over 767,000 RNA microarrays from human samples in public repositories, which are an invaluable resource for biomedical research and personalized medicine. The absolute gene expression analysis allows the transcriptome profiling of all expressed genes under the specific biological condition without the need of a reference sample. However, the background fluorescence represents a challenge to determine the absolute gene expression in microarrays. Given that the Y chromosome is absent in female subjects, we used it as a new approach for absolute gene expression analysis in which the fluorescence of the Y chromosome genes of female subjects was used as the background fluorescence for all the probes in the microarray. This fluorescence was used to establish an absolute gene expression threshold, allowing the differentiation between expressed and non-expressed genes in microarrays.
A novel approach for human whole transcriptome analysis based on absolute gene expression of microarray data.
Sex, Specimen part
View SamplesIntroduction: The genetic origin of familial combined hyperlipidemia (FCH) is not well understood. We used microarray profiling of peripheral blood monocytes to search novel genes and pathways involved in FCH. Methods: Fasting plasma for determination of lipid profiles, inflammatory molecules, and adipokines was obtained and peripheral blood monocytes were isolated from male FCH patients basally and after 4 weeks of atorvastatin treatment. Sex-, age- and adiposity-matched controls were also studied. Gene expression profile was analyzed using Affymetrix Human Genome U133A 2.0 GeneChip arrays. Results: Analysis of gene expression by cDNA microarrays showed that 82 genes were differentially expressed in FCH monocytes compared to controls. Atorvastatin treatment modified the expression of 87 genes. Changes in the expression of some genes, confirmed by real time RT-PCR, (CD36, leucine-rich repeats and immunoglobulin-like domains-1, tissue factor pathway inhibitor 2, myeloid cell nuclear differentiation antigen tumor necrosis factor receptor superfamily, member 25 and CD96) may be related to a proinflammatory environment in FCH monocytes, which is partially reversed by atorvastatin. Higher plasma levels of triglycerides and free fatty acids and lower levels of adiponectin in FCH patients could also trigger changes in gene expression that atorvastatin cannot modify. Conclusions: Our results demonstrate clear differences in gene expression in FCH monocytes compared with those of matched healthy controls, some of which are influenced by atorvastatin treatment.
Monocyte gene-expression profile in men with familial combined hyperlipidemia and its modification by atorvastatin treatment.
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View SamplesIn this study we analyzed the behavior of bone marrow MSC (BM-MSC) from MPN patients with the mutation in JAK2V617F. We initially characterized the biological function and gene expression profile changes in BM-MSC from MPN patients when compared to BM-MSC of healthy donors (HD). Then, we established co-cultures between MSC cell lines (HTERT and HS5) and the UKE-1 MPN cell line, and performed RT-PCR to study if the leukemic cells were able to modify the genes related to hematopoietic support.
Mesenchymal stromal cells (MSC) from JAK2+ myeloproliferative neoplasms differ from normal MSC and contribute to the maintenance of neoplastic hematopoiesis.
Specimen part, Disease stage, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Aberrant epigenome in iPSC-derived dopaminergic neurons from Parkinson's disease patients.
Sex, Specimen part, Disease, Disease stage, Subject
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