Recurrent somatic hotspot mutations of DICER1 appear to be clustered around each of four critical metal binding residues in the RNase IIIB domain of DICER1. This domain is responsible for cleavage of the 3 end of the 5p-miRNA strand of a pre-mRNA hairpin. To investigate the effects of these cancer-associated hotspot mutations we engineered mouse Dicer1-deficient ES cells to express wild-type and an allelic series of the mutant human DICER1 variants. Global miRNA and mRNA profiles from cells carrying the metal binding site mutations were compared to each other and wild-type human DICER1. The miRNA and mRNA profiles generated through the expression of the hotspot mutations were virtually identical, and the DICER1 hotspot mutation carrying cells were distinct from both wild-type and Dicer1-deficient cells. Further, miRNA profiles showed mutant DICER1 results in a dramatic loss in processing of mature 5p-miRNA strands but were still able to create 3p-strand miRNAs. Messenger-RNA profile changes were consistent with the loss of 5p-strand miRNAs and showed enriched expression for predicted targets of the lost 5p derived miRNAs. We therefore conclude that cancer-associated somatic hotspot mutations of DICER1, affecting any one of four metal binding residues in the RNase IIIB domain, are functionally equivalent with respect to miRNA-processing and are hypomorphic alleles, yielding a global loss in processing of mature 5p-strand miRNA. We further propose that this resulting 3p-strand bias in mature miRNA expression likely underpins the oncogenic potential of these hotspot mutations.
Cancer-associated somatic DICER1 hotspot mutations cause defective miRNA processing and reverse-strand expression bias to predominantly mature 3p strands through loss of 5p strand cleavage.
Specimen part
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 SamplesA distinct highly invasive subpopulation was identified in breast cancer cell lines. The molecular characteristics of these cells was investigated, revealing a set of genes whose high expression confers the ability to invade.
ΔNp63α Promotes Breast Cancer Cell Motility through the Selective Activation of Components of the Epithelial-to-Mesenchymal Transition Program.
Cell line
View SamplesWe conducted a time series of transcriptomics measurements during normal ageing in C. elegans in two non-reproductive strains (fem and gem) during normal ageing (days 1 to 10 of adulthood) and used this together with a multi-omics modelling pipeline to explore the changes that take place due to ageing. Overall design: Two strains and several time points with three replicates per strain and time point.
Multi-Omics and Genome-Scale Modeling Reveal a Metabolic Shift During <i>C. elegans</i> Aging.
Age, Specimen part, Subject
View SamplesPHF8 exerts distinct functions in different types of cancer. However, the mechanisms underlying its specific functions in each case remain obscure. To establish whether overexpression of PHF8 regulates the TGF-ß induced the epithelial-mesenchymal transition (EMT), we treated MCF10A-Mock (control) and MCF10A-PHF8wt (overexpressing wild-type PHF8) cells with TGF-ß1 for 0, 24, 48 and 72 hours and performed RNA-seq in biological duplicates. Our data indicated that EMT gene signatures were significantly enriched in MCF10A-PHF8 cells with TGF-ß1 treatment at all time points, strongly indicating that PHF8 overexpression induces a sustained EMT signaling program. Overall design: mRNA profiles of MCF10A-Mock (control) and MCF10A-PHF8 with TGF-ß1 treatment for 0, 24, 48 and 72 hours were generated by RNA-seq, in duplicate, using HiSeq2500 instrument.
Histone demethylase PHF8 promotes epithelial to mesenchymal transition and breast tumorigenesis.
No sample metadata fields
View SamplesWe sorted Eomes-negative NK cells (CD3- CD56+ CXCR6- CD16-) and Eomes-positive NK cells (CD3- CD56+ CXCR6+) from total leukocytes isolated from the perfusion fluid of five healthy human livers destined for transplantation. Total RNA was extracted from sorted cells, cDNA generated and RNASeq performed. Overall design: Examination of mRNA levels in paired Eomes-negative/Eomes-positive NK cells from the same donor.
Eomeshi NK Cells in Human Liver Are Long-Lived and Do Not Recirculate but Can Be Replenished from the Circulation.
Specimen part, Subject
View SamplesIt has long been appreciated that striped pair-rule transcription factor expression is necessary for convergent extension in the early Drosophila embryo, although the mechanisms that link these transcriptional regulators to planar polarity in this tissue have long been elusive. The goal of this study was to determine the transcriptional tragets of the pair-rule transcription factors Eve and Runt in Drosophila blastoderm embryos. We compared the transcriptional profiles of late blastoderm embryos injected with either water or dsRNAs against both eve and runt to identify differentially expressed genes that may directly contribute to the establishment of planar polarity during Drosophila convergent extension. Overall design: Comparing the mRNA profiles from late blastoderm Drosophila embryos injected with either water (Water) or eve+runt dsRNAs (Eve), in triplicate, using Illumina HiSeq.
A positional Toll receptor code directs convergent extension in Drosophila.
Subject
View SamplesBackground: Interaction between key signaling mechanisms is important to generate the diversity in signaling output required for proper control of cellular differentiation and function, although the molecular manifestations of such cross-talk are only partially understood. Notch signaling and the cellular response to hypoxia intersect at different points in the signaling cascades, and in this report we analyze the consequences of this cross-talk at the transcriptome level. Results: Mouse ES cells were subjected to various combinations of hypoxia and/or activated Notch signaling, and the transcriptome changes could be grouped into different categories, reflecting various modes of hypoxia and Notch signaling integration. Two principal categories of novel Notch- and hypoxia-induced genes were identified: i) a larger set of genes induced by one pathway and not significantly affected by the activity status of the other pathway; and ii) a smaller set of genes co-regulated by Notch and hypoxia. In the latter category, we identified genes that were induced by hypoxia and the expression of which was enhanced by active Notch signaling. In addition, a number of genes were induced by Notch and hypoxia independently, and a final category of genes required simultaneous activation of Notch and hypoxia to be significantly induced. Several of the hypoxia- and Notch-induced genes were found to be upregulated in various forms of cancer. Conclusions: We identify novel Notch and hypoxia downstream genes and genes co-regulated by the two pathways, providing a molecular platform to better understand the intersection between the two signaling cascades in normal development and cancer.
Interactions between Notch- and hypoxia-induced transcriptomes in embryonic stem cells.
Sex, Specimen part, Treatment
View SamplesThe genetic mechanism governing the spatial patterning of teeth still remains to be elucidated. Sonic hedgehog (Shh) is one of key signaling molecules involved in the spatial patterning of teeth. By utilizing maternal transfer of 5E1 (an IgG1 monoclonal antibody against Shh protein) through the placenta to block Shh signaling, we investigated the changes in tooth patterning and in gene expression.
Interactions between Shh, Sostdc1 and Wnt signaling and a new feedback loop for spatial patterning of the teeth.
Specimen part, Time
View SamplesComparison of transcriptome between control and Tcf1/Lef1-deficient mature CD8 thymocytes Overall design: Control mice or those are deficient for Tcf1 and Lef1 transcription factors (deleted by CD4-Cre) were used to isolate thymocytes. The thymocytes were surface-stained to identify TCRbeta high, CD69–, CD24– CD8+ subsets. These cells were sorted for RNAseq analysis.
Tcf1 and Lef1 transcription factors establish CD8(+) T cell identity through intrinsic HDAC activity.
Specimen part, Subject
View Samples