Mouse embryonic stem (ES) cells remain pluripotent in vitro when grown in presence of Leukaemia Inhibitory Factor (LIF). LIF starvation leads to apoptosis of some of the ES-derived differentiated cells, together with p38a MAP kinase activation. Apoptosis, but not morphological cell differentiation, is blocked by a p38 inhibitor, PD 169316. To further understand the mechanism of action of this compound, we have identified its specific targets by microarray studies. We report on the global expression profiles of genes expressed at three days upon LIF withdrawal (d3) compared to pluripotent cells and of genes whose expression is modulated at d3 under anti-apoptotic conditions. We showed that at d3 without LIF cells express, earlier than anticipated, specialized cell markers and that when the apoptotic process was impaired, expression of differentiation markers was altered. In addition, functional tests revealed properties of anti-apoptotic proteins not to alter cell pluripotency and a novel role for metallothionein 1 gene which prevents apoptosis of early differentiated cells.
Apoptosis and differentiation commitment: novel insights revealed by gene profiling studies in mouse embryonic stem cells.
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View SamplesWe sequenced mRNA extracted from heads of a D. melanogaster population that was sedated with a stream of ethanol saturated vapor, 30 minutes before RNA extraction; and from an age-matched untreated control group. Differential gene expression between the two groups was calculated and reported. Overall design: Examination of mRNA levels in heads of D. melanogaster adult females after ethanol exposure was performed using next generation sequencing (NGS) technology.
Alcohol resistance in Drosophila is modulated by the Toll innate immune pathway.
Cell line, Treatment, Subject
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Whole transcriptome analysis of the ERα synthetic fragment P295-T311 (ERα17p) identifies specific ERα-isoform (ERα, ERα36)-dependent and -independent actions in breast cancer cells.
Cell line
View SamplesER17p is a synthetic peptide corresponding to the sequence P295LMIKRSKKNSLALSLT311 of the estrogen receptor alpha (ER) and initially synthesized to mimic its calmodulin binding site. ER17p was subsequently found to elicit estrogenic responses in E2-deprived ER-positive breast cancer cells, increasing proliferation and E2-dependent gene transcription. Surprisingly, in E2-supplemented media, ER17p induced apoptosis and modified the actin network, influencing thereby cell motility. Here, we report that ER17p induces a massive early (3h) transcriptional activity in breast cancer cell lines SKBR3). Remarkably, about 75% of the significantly modified transcripts were also modified by E2, confirming the pro-estrogenic profile of ER17p. The different ER spectra of the used cell lines allowed us to extract a specific ER17p signature related to ER and its variant ER36. With respect to ER, the peptide activates nuclear (cell cycle, cell proliferation, nucleic acid and protein synthesis) and extranuclear signaling pathways. In contrast, through ER36 it exerts inhibitory events on inflammation and cell cycle and inhibition of EGFR signaling. This is the first work reporting ER36 specific transcriptional effects. The fact that a number ER17p-induced transcripts is different from those activated by E2 revealed that the apoptosis and actin modifying effects of ER17p are independent from the ER-related actions of the peptide.
Whole transcriptome analysis of the ERα synthetic fragment P295-T311 (ERα17p) identifies specific ERα-isoform (ERα, ERα36)-dependent and -independent actions in breast cancer cells.
Cell line
View SamplesER17p is a synthetic peptide corresponding to the sequence P295LMIKRSKKNSLALSLT311 of the estrogen receptor alpha (ER) and initially synthesized to mimic its calmodulin binding site. ER17p was subsequently found to elicit estrogenic responses in E2-deprived ER-positive breast cancer cells, increasing proliferation and E2-dependent gene transcription. Surprisingly, in E2-supplemented media, ER17p induced apoptosis and modified the actin network, influencing thereby cell motility. Here, we report that ER17p induces a massive early (3h) transcriptional activity in breast cancer cell line MDA-MB-231.
Whole transcriptome analysis of the ERα synthetic fragment P295-T311 (ERα17p) identifies specific ERα-isoform (ERα, ERα36)-dependent and -independent actions in breast cancer cells.
Cell line
View SamplesER17p is a synthetic peptide corresponding to the sequence P295LMIKRSKKNSLALSLT311 of the estrogen receptor alpha (ER) and initially synthesized to mimic its calmodulin binding site. ER17p was subsequently found to elicit estrogenic responses in E2-deprived ER-positive breast cancer cells, increasing proliferation and E2-dependent gene transcription. Surprisingly, in E2-supplemented media, ER17p induced apoptosis and modified the actin network, influencing thereby cell motility. Here, we report that ER17p induces a massive early (3h) transcriptional activity in breast cancer cell line T47D.
Whole transcriptome analysis of the ERα synthetic fragment P295-T311 (ERα17p) identifies specific ERα-isoform (ERα, ERα36)-dependent and -independent actions in breast cancer cells.
Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
ChIP-seq analysis reveals distinct H3K27me3 profiles that correlate with transcriptional activity.
Specimen part
View SamplesTranscriptional control is dependent on a vast network of epigenetic modifications. One epigenetic mark of particular interest is tri-methylation of lysine 27 on histone H3 (H3K27me3), which is catalyzed and maintained by the Polycomb Repressor Complex (PRC2). Although this histone mark is studied widely, the precise relationship between its local pattern of enrichment and regulation of gene expression is currently unclear. We have used ChIP-seq to generate genome wide maps of H3K27me3 enrichment, and have identified three enrichment profiles with distinct regulatory consequences. First, a broad domain of H3K27me3 enrichment across the body of genes corresponds to the canonical view of H3K27me3 as inhibitory to transcription. Second, a peak of enrichment around the transcription start site is commonly associated with bivalent genes, where H3K4me3 also marks the TSS. Finally and most surprisingly, we identified an enrichment profile with a peak in the promoter of genes that is associated with active transcription. Genes with each of these three profiles were found in different proportions in each of the cell types studied. The data analysis techniques developed here will be useful for the identification of common enrichment profiles for other histone modifications that have important consequences for transcriptional regulation.
ChIP-seq analysis reveals distinct H3K27me3 profiles that correlate with transcriptional activity.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Early membrane initiated transcriptional effects of estrogens in breast cancer cells: First pharmacological evidence for a novel membrane estrogen receptor element (ERx).
Specimen part, Cell line
View SamplesEstrogens have been reported to activate several processes via membrane binding to either classic estrogen receptors (ERs) or GPR30. We have used either estradiol or BSA-conjugated estradiol in order to initiate membrane-initiated actions and ICI 172,780 (ICI) or G15 to explore ER- and GPR30-related transcription. Our results show that the majority of G15-inhibited transcription is depending on ERs, as it is also inhibited by ICI. However, a small number of transcripts, related to specific actions/pathways is either exclusively inhibited by G15, providing evidence about a specific GPR30 signature, or not inhibited by ICI or G15 suggesting the existence of another, yet unidentified estrogen receptor.
Early membrane initiated transcriptional effects of estrogens in breast cancer cells: First pharmacological evidence for a novel membrane estrogen receptor element (ERx).
Specimen part, Cell line
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