Abstract: 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 SamplesRecurrent 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 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 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 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 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 SamplesTo study the senescence gene signatures in the cells, which were genetic SMARCB1 depleted or treated with aurora kinase inhibitors or etoposide, we performed next generation RNA sequencing on these cell, and ''FRIDMAN_SENESCENCE_UP'' geneset was used to determine the enrichment of senescence-related genes. The RNA sequencing results include (1) A375 cells and SMARCB1 depleted counterparts. (2) A549 cells and aurora kinase inhibitor (Alisertib, barasertib or tozasertib) or etoposide treated counterparts. Overall design: RNA seq data of A375_gSMARCB1 + A549_etoposide, Aurora kinases inhibitors treated, to check senescence gene expression signature one replicate of A375 cells parental V.S SMARCB1 KO (by CRISPR) + duplicates of A549 parental V.S etoposide, or 3 indepdent aurora kinase inhibitors (MLN8237/Alisertib, VX680/Tozasertib, AZD1132/Barasertib)
High-Throughput Functional Genetic and Compound Screens Identify Targets for Senescence Induction in Cancer.
Disease, Disease stage, Cell line, Subject
View SamplesWe addressed the clinical significance and mechanisms behind in vitro cellular responses to ionising radiation (IR)-induced DNA double strand breaks in 74 paediatric ALL patients. We found an apoptosis-resistant response in 36% of patients and an apoptosis-sensitive response in the remaining 64% of leukaemias. Global gene expression profiling of 11 apoptosis-resistant and 11 apoptosis-sensitive ALLs revealed abnormal up-regulation of multiple pro-survival pathways in response to IR in apoptosis-resistant leukaemias and differential post-transcriptional activation of the PI3-Akt pathway was observed in representative resistant cases. It is possible that abnormal pro-survival responses to DNA damage provide one of the mechanisms of primary resistance in ALL .
Stratification of pediatric ALL by in vitro cellular responses to DNA double-strand breaks provides insight into the molecular mechanisms underlying clinical response.
No sample metadata fields
View SamplesWe assessed the gene expression profile of purified CD205+CD8+ Dendritic Cells isolated from murine spleens.
NOD2 modulates immune tolerance via the GM-CSF-dependent generation of CD103<sup>+</sup> dendritic cells.
Sex, Age, Specimen part
View SamplesNasopharyngeal carcinoma (NPC) is a common cancer in southern China and South East Asia where more than 50,000 new cases are diagnosed each year.
The ATM tumour suppressor gene is down-regulated in EBV-associated nasopharyngeal carcinoma.
Disease, Disease stage
View Samples