The aim of the study was to get insights into transcriptional alterations in bone marrow mesenchymal stromal cells derived from acute myeloid leukemia patients
Molecular alterations in bone marrow mesenchymal stromal cells derived from acute myeloid leukemia patients.
Disease
View SamplesBackground. Androgen receptor splice variant-7 (AR-V7) is a truncated form of the androgen receptor protein which lacks the ligand-binding domain, the target of enzalutamide and abiraterone, but remains constitutively active as a transcription factor. We hypothesized that detection of AR-V7 in circulating tumor cells (CTCs) from men with advanced prostate cancer would be associated with resistance to enzalutamide and abiraterone. Methods. We used quantitative reverse-transcription polymerase-chain-reaction (qRT-PCR) to interrogate CTCs for the presence or absence of AR-V7 from prospectively enrolled patients with metastatic castration-resistant prostate cancer initiating treatment with either enzalutamide or abiraterone. We examined associations between AR-V7 status and PSA response rates, PSA-progression-free-survival (PSA-PFS), clinical/radiographic-progression-free-survival (PFS), and overall survival (OS). Multivariable Cox regression analyses were performed to determine the independent effect of AR-V7 status on clinical outcomes. Results. Thirty-one enzalutamide-treated patients and thirty-one abiraterone-treated patients were enrolled, of which 38.7% and 19.4% had detectable AR-V7 from CTCs, respectively. Among men receiving enzalutamide, AR-V7–positive patients had inferior PSA response rates (0% vs 52.6%, P=0.004), PSA-PFS (median: 1.4 vs 6.0 months, P<0.001), PFS (median: 2.1 vs 6.1 months, P<0.001), and OS (median: 5.5 months vs not reached, P=0.002) compared to AR-V7–negative patients. Similarly, among men receiving abiraterone, AR-V7–positive patients had inferior PSA response rates (0% vs 68.0%, P=0.004), PSA-PFS (median: 1.3 months vs not reached, P<0.001), PFS (median: 2.3 months vs not reached, P<0.001), and OS (median: 10.6 months vs not reached, P=0.006). The negative prognostic impact of AR-V7 was maintained after adjusting for full-length-AR expression. Conclusions. Detection of AR-V7 in CTCs from patients with castration-resistant prostate cancer is associated with resistance to enzalutamide and abiraterone. Overall design: A total of four metastatic castration-resistant prostate tumor samples from four patients were subjected to RNA-seq. Two samples were positive for androgen receptor splice variant 7 and the other two were negative for this variant.
AR-V7 and resistance to enzalutamide and abiraterone in prostate cancer.
No sample metadata fields
View SamplesSMARCB1 (Snf5/Ini1/Baf47) is a potent tumor suppressor, the loss of which serves as the diagnostic feature in Malignant Rhabdoid Tumors (MRT) and Atypical Teratoid/Rhabdoid Tumors (AT/RT), two highly aggressive forms of pediatric neoplasms. Here, we restore Smarcb1 expression in cells derived from Smarcb1-deficient tumors which developed in Smarcb1-heterozygous p53-/- mice.
Loss of IGFBP7 expression and persistent AKT activation contribute to SMARCB1/Snf5-mediated tumorigenesis.
Specimen part, Cell line
View SamplesGenes regulated by the fibroblast growth factor (FGF) signalling pathway were indentified in the early development of the amphibian Xenopus laevis by comparing gene expression in control embryos and embryos in which FGF signalling was inhibited by two different dominant negative FGF receptors.
Characterisation of the fibroblast growth factor dependent transcriptome in early development.
Age, Compound, Time
View SamplesMicroglia depletion significantly lowered spine density in young (developing) but not mature adult-born-granule-cells (abGCs) in the olfactory bulb. PLX5622 significantly reduces microglia related gene transcripts. Overall design: We tested mouse olfactory bulb transcription in WT mice versus mice treated with a PLX5622 diet (inducing a near-complete microglia depletion).
The role of microglia and their CX3CR1 signaling in adult neurogenesis in the olfactory bulb.
Specimen part, Cell line, Subject
View SamplesTo explore the global mechanisms of estrogen-regulated transcription, we used chromatin immunoprecipitation coupled with DNA microarrays to determine the localization of RNA polymerase II (Pol II), estrogen receptor alpha (ERalpha), steroid receptor coactivator proteins (SRC), and acetylated histones H3/H4 (AcH) at estrogen-regulated promoters in MCF-7 cells with or without estradiol (E2) treatment. In addition, we correlated factor occupancy with gene expression and the presence of transcription factor binding elements. Using this integrative approach, we defined a set of 58 direct E2 target genes based on E2-regulated Pol II occupancy and classified their promoters based on factor binding, histone modification, and transcriptional output. Many of these direct E2 target genes exhibit interesting modes of regulation and biological activities, some of which may be relevant to the onset and proliferation of breast cancers. Our studies indicate that about one-third of these direct E2 target genes contain promoter-proximal ERalpha-binding sites, which is considerably more than previous estimates. Some of these genes represent possible novel targets for regulation through the ERalpha/AP-1 tethering pathway. Our studies have also revealed several previously uncharacterized global features of E2-regulated gene expression, including strong positive correlations between Pol II occupancy and AcH levels, as well as between the E2-dependent recruitment of ERalpha and SRC at the promoters of E2-stimulated genes. Furthermore, our studies have revealed new mechanistic insights into E2-regulated gene expression, including the absence of SRC binding at E2-repressed genes and the presence of constitutively bound, promoter-proximally paused Pol IIs at some E2-regulated promoters. These mechanistic insights are likely to be relevant for understanding gene regulation by a wide variety of nuclear receptors.
Genomic analyses of transcription factor binding, histone acetylation, and gene expression reveal mechanistically distinct classes of estrogen-regulated promoters.
No sample metadata fields
View SamplesTIMP-2 is an endogenous angiogenesis inhibitor, i.e. inhibits endothelial cell proliferation and tumor angiogenesis. As a result, TIMP-2 inhibits tumor growth and progression to metastasis. Understanding, therefore, the mechanisms of TIMP-2-mediated tumor growth inhibition would provide further support on the use of TIMP-2 as a novel biological agent for cancer therapy. We used microarray analysis to determine the TIMP-2 and Ala+TIMP-2 transcriptional profiles of A549 cancer cells in order to understand how TIMP-2 inhibits tumor growth and angiogenesis.
TIMP-2 modulates cancer cell transcriptional profile and enhances E-cadherin/beta-catenin complex expression in A549 lung cancer cells.
Specimen part, Cell line
View SamplesGene regulatory networks that govern hematopoietic stem cells (HSC) and leukemiainitiating cells (L-IC) are deeply entangled. Thus, the discovery of compounds that target L-IC while sparing HSC is an attractive but difficult endeavor. Presently, most drug discovery approaches fail to counter-screen compounds against normal hematopoietic stem/progenitor cells (HSPC) to assess therapeutic index. Here, we present a combined in vitro and in vivo strategy to identify compounds specific to L-IC in acute myeloid leukemia (AML). A high-throughput screen of 4000 compounds on novel leukemia cell lines derived from human experimental leukemogenesis models yielded 80 hits, of which most were toxic to normal HSPC. Of the 10 compounds that passed this initial filter, we chose to characterize a single compound, kinetic riboside (KR), on AML L-IC and HSPC. KR demonstrated comparable efficacy to standard therapies against 63 primary AMLs. In vitro, KR effectively targeted the L-IC-enriched CD34+CD38- AML fraction, while sparing normal HSPC enriched fractions, although these effects were mitigated on HSC assayed in vivo, and highlights the importance of in vivo L-IC and HSC assays to measure function. Overall, we provide a novel approach to screen large drug libraries for the discovery of anti-L-IC compounds for human leukemias.
A small molecule screening strategy with validation on human leukemia stem cells uncovers the therapeutic efficacy of kinetin riboside.
Cell line, Treatment
View SamplesPurpose: Next-generation sequencing (NGS) has revolutionized systems-based analysis of cellular pathways. The goals of this study are to compare NGS-derived femoral diaphysis and metaphysis transcriptome profiling (RNA-seq) to determine pathways and networks dependent on Dlx3 during bone development and homeostasis. Methods: mRNA profiles of diaphysis and metaphysis isolated from the femur of 5-week-old wild-type (WT) and Dlx3Oc-cKO (OC-cre;Dlx3f/-) conditional knockout mice were generated by deep sequencing, in triplicate, using Illumina HiSeq 2000. The sequence reads that passed quality filters were analyzed at the transcript isoform level by ANOVA (ANOVA) and TopHat. qRT-PCR validation was performed using SYBR Green assay. Results: RNA-Seq data were generated with Illumina''s HiSeq 2000 system. Raw sequencing data were processed with CASAVA 1.8.2 to generate fastq files. Reads of 50 bases were mapped to the mouse transcriptome and genome mm9 using TopHat 1.3.2. Gene expression values (RPKM) were calculated with Partek Genomics Suite 6.6, which was also used for the ANOVA analysis to determine significantly differentially expressed genes. Conclusions: Our study represents the first detailed analysis of Dlx3Oc-cKO diaphysis and metaphysis from femurs, with biologic triplicates, generated by RNA-seq technology. The optimized data analysis workflows reported here should provide a framework for comparative investigations of expression profiles. We conclude that RNA-seq based transcriptome characterization would expedite genetic network analyses and permit the dissection of complex biologic functions. Overall design: Diaphysis and metaphysis mRNA profiles of metaphysis and diaphysis from femurs of 5-wk-old (WT) and Dlx3Oc-cKO male mice were generated by deep sequencing, in triplicate, using Illumina HiSeq 2000.
DLX3 regulates bone mass by targeting genes supporting osteoblast differentiation and mineral homeostasis in vivo.
No sample metadata fields
View SamplesHighly quantitative biomarkers of neurodegenerative disease remain an important need in the urgent quest for disease modifying therapies. For Huntington's disease (HD), a genetic test is available (trait marker), but necessary state markers are still in development. In this report, we describe a large battery of transcriptomic tests explored as state biomarker candidates. In an attempt to exploit the known neuroinflammatory and transcriptional perturbations of disease, we measured relevant mRNAs in peripheral blood cells. The performance of these potential markers was weak overall, with only one mRNA, immediate early response 3 (IER3), showing a modest but significant increase of 32% in HD samples compared to controls. No statistically significant differences were found for any other mRNAs tested, including a panel of 12 RNA biomarkers identified in a previous report [Borovecki F, Lovrecic L, Zhou J, Jeong H, Then F, Rosas HD, Hersch SM, Hogarth P, Bouzou B, Jensen RV et al. (2005) Proc Natl Acad Sci U S A 102: 11023-11028]. The present results may nonetheless inform the future design and testing of HD biomarker strategies.
Analysis of potential transcriptomic biomarkers for Huntington's disease in peripheral blood.
No sample metadata fields
View Samples