JQ1 is a small-molecule (BET family) bromodomain inhibitor that causes a contraceptive effect in mice by blocking spermatogenesis and reducing sperm motility.
Small-molecule inhibition of BRDT for male contraception.
Sex, Specimen part
View SamplesTo understand the molecular curcuits perturbed by BET bromodoman inhibtion we obtained gene expression profiling of five DLBCL cell lines, SU-DHL6, OCI-Ly1, OCI-Ly4, Toledo and HBL-1, which were treated with either 500nM JQ1 or DMSO for 0,2,6,12,24 and 48hr.
Discovery and characterization of super-enhancer-associated dependencies in diffuse large B cell lymphoma.
Specimen part, Cell line, Treatment, Time
View SamplesWe investigated the transcriptional effects of p63 binding by analyzing ME180 cells depleted for all p63 isoforms via expression of a small hairpin RNA (shRNA) targeting the p63 oligomerization domain.
Relationships between p63 binding, DNA sequence, transcription activity, and biological function in human cells.
Age
View SamplesPathologic activation of c-Myc plays a central role in pathogenesis of several neoplasias, including multiple myeloma. However, therapeutic targeting of c-Myc has remained elusive due to its lack of a clear ligand-binding domain. We therefore targeted c-Myc transcriptional function by another means, namely the disruption of chromatin-dependent signal transduction. Members of the bromodomain and extra-terminal (BET) subfamily of human bromodomain proteins (BRD2, BRD3 and BRD4) associate with acetylated chromatin and facilitate transcriptional activation by increasing the effective molarity of recruited transcriptional activators. Notably, BRD4 marks select M/G1 genes in mitotic chromatin for transcriptional memory and direct post-mitotic transcription, via direct interaction with the positive transcription elongation factor complex b (P-TEFb). Because c-Myc is known to regulate promoter-proximal pause release of Pol II, also through the recruitment of P-TEFb, we evaluated the selective small-molecule inhibitor of BET bromodomains, JQ1, as a chemical probe to interrogate the role of BET bromodomains in Myc-dependent transcription and to explore their role as therapeutic targets in c-Myc-driven neoplasias.
BET bromodomain inhibition as a therapeutic strategy to target c-Myc.
Specimen part, Cell line, Treatment
View SamplesThe transcriptional events accompanying synaptogenesis are largely unknown, or have been studied in systems in which synapse formation occurs gradually over time. With a system in which synaptogenesis is synchronized and controllable, molecular or biochemical techniques can be used to examine cellular events across cultures on a wide scale, as synapses develop.
Synaptogenesis in purified cortical subplate neurons.
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View SamplesThe oviducts contain high grade serous cancer precursors, which are -H2AXp and p53 mutation positive. Secretory cell outgrowths (SCOUTs) are associated with older age and serous cancer. We evaluated PAX2 expression in proliferating oviductal cells, normal mucosa, SCOUTs, Walthard cell nests, STINs and HGSCs. Non-ciliated cells in normal mucosa were PAX2 positive but became PAX2 negative in multilayered epithelium. PAX2 negative SCOUTs fell into two groups; Type I were secretory or secretory/ciliated with a tubal phenotype and were ALDH1 negative. Type II displayed a columnar to pseudostratified phenotype, with an EZH2,ALDH1, -catenin, Stathmin, LEF1, RCN1 and RUNX2 expression signature . This study, for the first time, links PAX2 negative with proliferating fetal and adult oviductal cells undergoing basal and ciliated differentiation and shows that this expression state is maintained in SCOUTs, STINs and HGSCs. All three entities can demonstrate a consistent perturbation of genes involved in potential tumor suppressor gene silencing (EZH2), transcriptional regulation (LEF1), regulation of differentiation (RUNX2) calcium binding (RCN1) and oncogenesis (Stathmin). This shared expression signature between benign and neoplastic entities links normal progenitor cell expansion to abnormal and neoplastic outgrowth in the oviduct and exposes a common pathway that could be a target of early prevention.
The PAX2-null immunophenotype defines multiple lineages with common expression signatures in benign and neoplastic oviductal epithelium.
Sex, Specimen part, Disease
View SamplesAbstract: During Drosophila oogenesis, germline stem cell (GSC) identity is maintained largely by preventing the expression of factors that promote differentiation. This is accomplished via the activity of several genes acting either in the GSC or its niche. The translational repressors, Nanos and Pumilio, act in GSCs to prevent differentiation, likely by inhibiting translation of early differentiation factors, while niche signals prevent differentiation by silencing transcription of the differentiation factor Bam. We have found that the DNA-associated protein Stonewall (Stwl) is also required for GSC maintenance. stwl is required cell-autonomously; clones of stwl- germ cells were lost by differentiation, and ectopic Stwl caused an expansion of GSCs. stwl mutants acted as Suppressors of Variegation, indicating stwl normally acts in chromatin-dependent gene repression. In contrast to several previously described GSC maintenance factors, Stwl likely functions epigenetically to prevent GSC differentiation. Stwl-dependent transcriptional repression does not target bam, but rather Stwl represses the expression of many genes, including those that may be targeted by Nanos/Pumilio translational inhibition.
Stonewalling Drosophila stem cell differentiation by epigenetic controls.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Distal airway stem cells yield alveoli in vitro and during lung regeneration following H1N1 influenza infection.
Specimen part
View SamplesThe extent of lung regeneration following catastrophic damage and the potential role of adult stem cells in such a process remains obscure. Sublethal infection of mice with an H1N1 influenza virus related to that of the 1918 pandemic triggers massive airway damage followed by apparent regeneration. We show here that p63-expressing stem cells in the bronchiolar epithelium undergo rapid proliferation after infection and radiate to interbronchiolar regions of alveolar ablation. Once there, these cells assemble into discrete, Krt5+ pods and initiate expression of markers typical of alveoli. Gene expression profiles of these pods suggest that they are intermediates in the reconstitution of the alveolar-capillary network eradicated by viral infection. The dynamics of this p63-expressing stem cell in lung regeneration mirrors our parallel findings that defined pedigrees of human distal airway stem cells assemble alveoli-like structures in vitro and suggests new therapeutic avenues to acute and chronic airway disease.
Distal airway stem cells yield alveoli in vitro and during lung regeneration following H1N1 influenza infection.
No sample metadata fields
View SamplesTriple negative breast cancer (TNBC) is a heterogeneous and clinically aggressive disease for which there is no targeted therapy. Here we report the preferential and high sensitivity of TNBCs to BET bromodomain inhibitors such as JQ1 manifested by cell cycle arrest in early G1, apoptosis, and induction of markers of luminal epithelial differentiation in vitro and in vivo. The sensitivity of TNBC and other tumor types to BET inhibition establishes a rationale for clinical investigation, and a motivation to understand mechanisms of resistance. After engendering acquired resistance to BET inhibition in previously sensitive TNBCs, we utilized integrative approaches to identify a unique mechanism of epigenomic resistance to this epigenetic therapy. Resistant cells remain dependent on BRD4, confirmed by RNA interference. However, TNBC cells adapt to BET bromodomain inhibition by re-recruitment of unmutated BRD4 to super-enhancers, now in a bromodomain-independent manner. Proteomic studies of resistant TNBC identify hyper-phosphorylation of BRD4 and strong association with MED1. Together, these studies provide a rationale for BET inhibition in TNBC and argue for combination strategies to anticipate clinical drug resistance. Overall design: RNA-Seq in parental and JQ1 resistant triple negative breast cancer (TNBC) in response to DMSO or JQ1 treatment over time
Response and resistance to BET bromodomain inhibitors in triple-negative breast cancer.
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