Cellular senescence is a program of irreversible cell cycle arrest that normal cells undergo in response to progressive shortening of telomeres, changes in telomeric structure, oncogene activation or oxidative stress. The underlying signalling pathways, potentially of major clinicopathological relevance, are unknown. A major stumbling block to studying senescence has been the absence of suitable model systems because of the asynchrony of this process in heterogeneous cell populations. To simplify this process many investigators study oncogene-induced senescence due to expression of activated oncogenes where senescence occurs prematurely without telomere attrition and can be induced acutely in a variety of cell types. We have taken a different approach by making use of the finding that reconstitution of telomerase activity by introduction of the catalytic subunit of human telomerase alone is incapable of immortalising all human somatic cells, but inactivation of the p16-pRB and p53-p21 pathways are required in addition. The ability of SV40 large T antigen to inactivate the p16-pRB and p53-p21 pathways has enabled us to use a thermolabile mutant of LT antigen, in conjunction with hTERT, to develop conditionally immortalised human (HMF3A) fibroblasts that are immortal but undergo an irreversible growth arrest when the thermolabile LT antigen is inactivated leading to activation of pRB and p53. When these cells cease dividing, senescence-associated- b-galactosidase activity is induced and the growth-arrested cells have morphological features and express genes in common with senescent cells. Since these cells growth arrest in a synchronous manner they are an excellent starting point for dissecting the pathways that underlie cellular senescence and act downstream of p16-pRB and p53-p21 pathways. We have combined genome-wide expression profiling with genetic complementation to undertake identification of genes that are differentially expressed when these conditionally immortalised human fibroblasts undergo senescence upon activation of the p16-pRB and p53-p21 tumour suppressor pathways.
Activation of nuclear factor-kappa B signalling promotes cellular senescence.
Cell line, Treatment
View SamplesJust as animal monozygotic twins can experience different environmental conditions by being reared apart, individual genetically-identical trees of the genus Populus can also be exposed to contrasting environmental conditions by being grown in different locations. As such, clonally-propagated Populus trees provide an opportunity to interrogate the impact of individual environmental history on current response to environmental stimuli. To test the hypothesis that current responses to an environmental stimulus, drought, are contingent on environmental history, the transcriptome-level drought responses of three economically important hybrid genotypes: DN34 (Populus deltoides x P. nigra); Walker (P. deltoides var. occidentalis x (P. laurifolia x P. nigra)); and, Okanese (Walker x (P. laurifolia x P. nigra)) derived from two different locations were compared. Strikingly, differences in transcript abundance patterns in response to drought were based on differences in geographic origin of clones for two of the three genotypes. This observation was most pronounced for the genotypes with the longest time since establishment and last common propagation. Differences in genome-wide DNA methylation paralleled the transcriptome level trends, where the clones with the most divergent transcriptomes and clone history had the most marked differences in the extent of total DNA methylation, suggesting an epigenetic basis for the clone-history-dependent transcriptome divergence. The data provide insights into the interplay between genotype and environment in the ecologically and economically important Populus genus, with implications for both the industrial application of Populus trees, and the evolution and persistence of these important tree species.
Clone history shapes Populus drought responses.
Specimen part, Treatment
View SamplesPurpose: In this study, we identify global transcriptome alterations following removal of individual or multiple miR-196 family members in mouse. Next generation sequencing-derived transcriptome profiling (RNA-seq) was performed. Methods: A GFP reporter cassette was engineered to replace the mature miR-196a1 and miR-196a2 miRNA genomic loci in mouse (creating a knockout). GFP positive cells from an extensive knock-out allellic series of the three individual miR-196 genes, as detailed below, were isolated from E9.5 mouse embryos by FACS. miR-196b knockout cells were not marked with a fluorescent reporter and an assumption of co-expression with miR-196a2 was made. mRNA profiles were generated by deep sequencing in a minimum of four biological replicates per genotype, using an Illumina HiSeq 2000 instrument. Read information was mapped to the mouse genome and processed as described. Conclusions: Our study represents the first detailed analysis of embryonic transcriptomes following loss of single and multiple miR-196 family members. We identify complex dysregulation of many Hox genes, in addition to key developmental signalling pathways involved in somitogenesis. Overall design: mRNA profiles of E9.5 mouse embryos with miR-196 loss-of-function were generated by deep sequencing, in a minimum of four biological replicates, using Illumina HiSeq 2000.
Independent regulation of vertebral number and vertebral identity by microRNA-196 paralogs.
No sample metadata fields
View SamplesNaive pluripotent embryonic stem cells (ESCs) and embryonic germ cells (EGCs) are derived from the preimplantation epiblast and primordial germ cells (PGCs), respectively. We investigated whether differences exist between ESCs and EGCs, in view of their distinct developmental origins. PGCs are programmed to undergo global DNA demethylation; however, we find that EGCs and ESCs exhibit equivalent global DNA methylation levels. Importantly, inhibition of Erk and Gsk3b by 2i conditions leads to pronounced reduction in DNA methylation in both cell types. This is driven by Prdm14 and is associated with downregulation of Dnmt3a and Dnmt3b. However, genomic imprints are maintained in 2i, and we report derivation of EGCs with intact genomic imprints. Collectively, our findings establish that culture in 2i instills a naive pluripotent state with a distinctive epigenetic configuration that parallels molecular features observed in both the preimplantation epiblast and nascent PGCs.
Naive pluripotency is associated with global DNA hypomethylation.
Sex, Specimen part
View SamplesMasitinib is a tyrosine kinase inhibitor of c-Kit, PDGFR and , and to some extent Lyn of the Src kinase family. We evaluated the therapeutic potential of masitinib in vitro on human pancreatic tumour cell lines and in vivo in a mouse model of human pancreatic cancer.
Masitinib combined with standard gemcitabine chemotherapy: in vitro and in vivo studies in human pancreatic tumour cell lines and ectopic mouse model.
Specimen part, Cell line, Treatment
View SamplesWe compared the transcriptom between respondrs and non-responders before and after PD-1 blockade therapy in melanoma patients, and defined their difference in context of T cell function. Overall design: We had 4 sapmles from 2 cohorts of patients collected before and after PD-1 ICI therapy according to their responses to PD-1 ICI therapy.
CX3CR1 identifies PD-1 therapy-responsive CD8+ T cells that withstand chemotherapy during cancer chemoimmunotherapy.
Subject
View SamplesResponse to immune checkpoint inhibitors may be improved through combinations with each other and other therapies, raising questions about non-redundancy and resistance. We report results from parallel studies of melanoma patients and mice treated with anti-CTLA4 and radiation (RT). Although combined treatment improved responses, resistance was common. Computational analyses of immune and transcriptomic profiles (provided here) revealed that resistance in mice was due to upregulation of tumor PD-L1 that drives T cell exhaustion. Accordingly, optimal response requires RT, anti-CTLA4, and anti-PD-L1. Anti-CTLA4 inhibits Tregs, RT diversifies and shapes the TCR repertoire, and anti-PD-L1 reinvigorates exhausted T cells. Together, all three therapies promote the expansion of clonotypes with distinct TCR traits. Similar to mice, patients with melanoma showing high PD-L1 did not respond to RT + anti-CTLA4, demonstrated persistent T cell exhaustion, and rapidly progressed. Thus, the combination of RT, anti-CTLA4, and anti-PD-L1 promotes response through distinct mechanisms.
Radiation and dual checkpoint blockade activate non-redundant immune mechanisms in cancer.
No sample metadata fields
View SamplesRNA sequencing was performed on RNA isolated from baseline biopsies from UC patients enrolled in the Phase II EUCALYPTUS study of etrolizumab. Gene expression differences were identified in a subset of anti-TNF naïve patients that achieved clinical remission at 10 weeks in response to etrolizumab. Overall design: Baseline colonic biopsies from UC patients treated with etrolizumab were sequenced by the Illumina HiSeq 2000 Sequencing System.
Association Between Response to Etrolizumab and Expression of Integrin αE and Granzyme A in Colon Biopsies of Patients With Ulcerative Colitis.
No sample metadata fields
View Samplesp63 mutations have been associated with several human hereditary disorders characterized by ectodermal dysplasia such as EEC syndrome, ADULT syndrome and AEC syndrome . The location and functional effects of the mutations that underlie these syndromes reveal a striking genotype-phenotype correlation. Unlike EEC and ADULT that result from missense mutations in the DNA-binding domain of p63, AEC is solely caused by missense mutations in the SAM domain of p63. We report a study on the TAp63a isoform, the first to be expressed during development of the embryonic epithelia, and on its naturally occurring Q540L mutant derived from an AEC patient. To assess the effects of the Q540L mutation, we generated stable cell lines expressing TAp63a wt, DeltaNp63 alpha or the TAp63 alpha-Q540L mutant protein and used them to systematically compare the cell growth regulatory activity of the mutant and wt p63 proteins and to generate, by microarray analysis, a comprehensive profile of differential gene expression. We found that the Q540L substitution impairs the transcriptional activity of TAp63a and causes misregulation of genes involved in the control of cell growth and epidermal differentiation.
The Hay Wells syndrome-derived TAp63alphaQ540L mutant has impaired transcriptional and cell growth regulatory activity.
No sample metadata fields
View SamplesOchratoxin A gene expression profiling in liver and kidney, with time points of exposure from 7 days to 12 motnhs
A toxicogenomics approach to identify new plausible epigenetic mechanisms of ochratoxin a carcinogenicity in rat.
No sample metadata fields
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