To determine the prevalence of cotranscriptional splicing in Drosophila, we sequenced nascent RNA transcripts from Drosophila S2 cells as well as from Drosophila heads. 87% of introns assayed manifest more than 50% cotranscriptional splicing. The remaining 13% are cotranscriptionally spliced poorly, or slowly, with ~3% being almost completely retained in nascent pre-mRNA. Although individual introns showed slight but statistically significant differences in splicing efficiency, similar global levels of splicing were seen from both sources. Importantly, introns with low cotranscriptional splicing efficiencies are present in the same primary transcript with efficiently spliced introns, indicating that splicing is intron-specific. The analysis also indicates that cotranscriptional splicing is less efficient for first introns, longer introns and introns annotated as alternative. FinallyFinally, S2 cells expressing the slow RpII215C4 mutant manifest substantially less intron retention than wild-type S2 cells. Overall design: Examination of Total pA and Nascent RNA from 2 different cell populations and isolated fly heads.
Nascent-seq indicates widespread cotranscriptional pre-mRNA splicing in Drosophila.
Specimen part, Cell line, Treatment, Subject
View SamplesUsing the recently described CD104+/CD44hi antigen combination we demonstrate that tumorigenicity depends on individual cells residing in a hybrid E/M state. Acquisition of this E/M hybrid state is facilitated by the differential expression of EMT- TFs, like Snail accompanied by the expression of adult stem-cell programs. Transition from the highly tumorigenic E/M state to a fully mesenchymal phenotype, achieved by constitutive ectopic expression of Zeb1, is sufficient to drive cells out of the E/M hybrid state into an extreme mesenchymal (xM) state, which is accompanied by a substantial loss of tumorigenicity and a switch from canonical to non-canonical Wnt signaling. Overall design: Performing RNASeq with HMLE (immortalized human mammary epithelial cells) in different EMT stages, either in the E state the hybrid E/M state or the extreme mesenchymal (xM) state as determined by sorting for CD104 and CD44. And performing RNASeq with HMLE cells locked in the xE state by Zeb1KO (xE-SCC-Zeb1KO), from there transferred to the hybrid E/M state by Snail overexpression (E-SCC-Zeb1KOSn) or rescued and transitioned to an xM state with CRISPR resistant Zeb1 wobble mutant (mt) (E-SCC-Zeb1KOSnZmt).
Acquisition of a hybrid E/M state is essential for tumorigenicity of basal breast cancer cells.
Specimen part, Subject
View SamplesOne critical task in pluripotent reprogramming is to erase the somatic transcriptional program of starting cells. No strategy or theory exists for achieving erasure of somatic gene expression memory. Here, we present a proof-of-principle strategy in which reprogramming to pluripotency is facilitated by small molecules that erase somatic cell transcription memory. We show that mild chemical targeting of the acetyllysine-binding pockets of the BET bromodomains, the transcriptional bookmarking domains, robustly enhances reprogramming. Furthermore, we show that chemical targeting of the transcriptional bookmarking BET bromodomains dramatically downregulates specific somatic gene expression programs in both naïve and reprogramming fibroblasts. Chemical blocking of the BET bromodomains also resulted in loss of fibroblast morphology early in reprograming. In this study, we experimentally demonstrate a concept for cell fate conversion: facilitating the conversion by chemically targeting the transcriptional bookmarking BET bromodomains responsible for transcriptional memory. Overall design: human BJ cells were treated with JQ1 at 50 nM for 48 hours. Differential expression was compared with DMSO treatment. The same treatments and comparsion were conducted for reprogramming BJ cells, which were transduced with OCT4, SOX2, and KLF4. JQ1iPSC5 is a iPSC (induced pluripotent stem cell) line generated in this study using small molecules JQ1.
Reprogramming by De-bookmarking the Somatic Transcriptional Program through Targeting of BET Bromodomains.
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View SamplesThe MUC1 oncoprotein is aberrantly overexpressed in diverse human malignancies including breast and lung cancer. Although MUC1 modulates the activity of several transcription factors, there is no information regarding the effects of MUC1 on global gene expression patterns and the potential role of MUC1-induced genes in predicting outcome for cancer patients. We have developed an experimental model of MUC1-induced transformation that has identified the activation of gene families involved in oncogenesis, angiogenesis and extracellular matrix remodeling. A set of experimentally-derived MUC1-induced genes associated with tumorigenesis was applied to the analysis of breast and lung adenocarcinoma cancer databases. A 35-gene MUC1-induced tumorigenesis signature (MTS) predicts significant decreases in both disease-free and overall survival in patients with breast (n = 295) and lung (n = 442) cancers. The data demonstrate that the MUC1 oncoprotein contributes to the regulation of genes that are highly predictive of clinical outcome in breast and lung cancer patients.
MUC1-induced alterations in a lipid metabolic gene network predict response of human breast cancers to tamoxifen treatment.
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View SamplesThis SuperSeries is composed of the SubSeries listed below.
STAT1 is overexpressed in tumors selected for radioresistance and confers protection from radiation in transduced sensitive cells.
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View SamplesThis SuperSeries is composed of the SubSeries listed below.
Hijacking a key chromatin modulator creates epigenetic vulnerability for MYC-driven cancer.
Specimen part, Treatment
View SamplesNu61, a radiation-resistant human tumor xenograft, was selected from a parental radiosensitive tumor SCC-61 by eight serial cycles of passage in athymic nude mice and in vivo irradiation.
STAT1 is overexpressed in tumors selected for radioresistance and confers protection from radiation in transduced sensitive cells.
No sample metadata fields
View SamplesNu61, a radiation-resistant human tumor xenograft, was selected from a parental radiosensitive tumor SCC-61 by eight serial cycles of passage in athymic nude mice and in vivo irradiation.
STAT1 is overexpressed in tumors selected for radioresistance and confers protection from radiation in transduced sensitive cells.
No sample metadata fields
View SamplesNu61, a radiation-resistant human tumor xenograft, was selected from a parental radiosensitive tumor SCC-61 by eight serial cycles of passage in athymic nude mice and in vivo irradiation.
STAT1 is overexpressed in tumors selected for radioresistance and confers protection from radiation in transduced sensitive cells.
No sample metadata fields
View SamplesIt remains unclear how epigenetic modulators impact the tumorigenic potential of Myc. Here we show that the core subunits, including Dpy30, of the major H3K4 methyltransferase complexes are selectively upregulated in Burkitt lymphoma, and Dpy30 is important for efficient genomic binding of Myc. Dpy30 heterozygosity does not affect normal animal physiology, but significantly suppressed lymphomagenesis and reduced expression of a subset of key pro-survival genes when Myc is hyper-activated. Dpy30 heterozygosity also impedes cellular transformation without affecting normal cell growth. These results suggest that Myc hijacks this chromatin modulator to coordinate its oncogenic program for efficient tumorigenesis, meanwhile creating epigenetic vulnerability, which we then exploited by specifically targeting Dpy30s activity to inhibit growth of the Burkitt lymphoma cell model.
Hijacking a key chromatin modulator creates epigenetic vulnerability for MYC-driven cancer.
Specimen part, Treatment
View Samples