Triple-negative breast cancer (TNBC) patients with residual disease after neoadjuvant chemotherapy generally have worse outcome; however, some patients with residual tumor after neoadjuvant chemotherapy do not relapse. We hypothesize that there are subgroups of chemoresistant TNBC patients with different prognosis. In this study, 25 chemoresistant samples from 47 neoadjuvant chemotherapy-treated TNBC (The Methodist Hospital) are chosen for study
Identification of prognosis-relevant subgroups in patients with chemoresistant triple-negative breast cancer.
Age, Specimen part, Disease, Disease stage
View SamplesX-chromosome inactivation (XCI) provides a dosage compensation mechanism where, in each female cell, one of the two X chromosomes is randomly silenced. However, some genes on the inactive X chromosome and outside the pseudoautosomal regions escape from XCI and are expressed from both alleles (escapees). We investigated XCI at single-cell resolution combining deep single cellRNA sequencing with whole-genome sequencing to examine allelic-specific expression in 935 primary fibroblast and 48 lymphoblastoid single cells from five female individuals. In this framework we integrated an original method to identify and exclude doublets of cells. In fibroblast cells, we have identified 55 genes as escapees including five novel escapee genes. Moreover, we observed that all genes exhibit a variable propensity to escape XCI in each cell and cell type and that each cell displays a distinct expression profile of the escapee genes. A metric, the Inactivation Score—defined as the mean of the allelic expression profiles of the escapees per cell—enables us to discover a heterogeneous and continuous degree of cellular XCI with extremes represented by “inactive” cells, i.e., cells exclusively expressing the escaping genes from the active X chromosome and “escaping” cells expressing the escapees from both alleles. We found that this effect is associated with cell-cycle phases and, independently, with the XIST expression level, which is higher in the quiescent phase (G0). Single-cell allele-specific expression is a powerful tool to identify novel escapees in different tissues and provide evidence of an unexpected cellular heterogeneity of XCI. Overall design: Single-cell RNA seq study on 935 human fibroblasts and 48 lymphoblastoid cells from 5 female individuals, in order to investigate the X chromosome nactivation mechanism on a single cell level and to identify escapee genes
Single cell transcriptome in aneuploidies reveals mechanisms of gene dosage imbalance.
Specimen part, Subject
View SamplesMutations in the CLN3 gene lead to juvenile neuronal ceroid lipofuscinosis, a pediatric neurodegenerative disorder characterized by visual loss, epilepsy and psychomotor deterioration. Although most CLN3 patients carry the same 1 kb deletion in the CLN3 gene, their disease phenotype can be variable. The aims of this study were (1) to identify genes that are dysregulated in CLN3 disease regardless of the clinical course that could be useful as biomarkers, and (2) to find modifier genes that affect the progression rate of the disease.
Analysis of potential biomarkers and modifier genes affecting the clinical course of CLN3 disease.
Sex, Age, Specimen part, Disease, Disease stage
View SamplesSchizophrenia and other psychiatric disorders are postulated to be developmental disorders resulting from synapse dysfunction. How susceptibility genes for major mental disorders could lead to synaptic deficits in humans is not well-understood. Here we generated induced pluripotent stem cells (iPSCs) from four members of a family in which a frame-shift mutation of Disrupted-in-schizophrenia-1 (DISC1) co-segregated with psychiatric disorders and further produced different isogenic iPSC lines via genetic editing. We showed that mutant DISC1 causes synaptic vesicle release deficits in iPSC-derived forebrain neurons. Mechanistically, mutant DISC1 dysregulates the expression of many genes related to synapses and psychiatric disorders and depletes wild-type DISC1 and the NCoR1 transcription co-repressor complex. Furthermore, mechanism-guided pharmacological inhibition of phosphodiesterases rescues synaptic defects in mutant neurons. Our study uncovers a novel gain-of-function mechanism through which the psychiatric disorder-relevant mutation affects synaptic functions via transcriptional dysregulation and provides insight into the molecular and synaptic etiopathology of psychiatric disorders. Overall design: Two patient derived iPSC lines carrying heterozygous 4bp deletion in DISC1 gene and 1 related control were analyzed in biological triplicate
Synaptic dysregulation in a human iPS cell model of mental disorders.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Patterns of histone H3 lysine 27 monomethylation and erythroid cell type-specific gene expression.
Specimen part, Cell line
View SamplesERYTHROID CELL-TYPE SPECIFIC GENE EXPRESSION
Patterns of histone H3 lysine 27 monomethylation and erythroid cell type-specific gene expression.
Cell line
View SamplesDifferentiation of muscle tissue is regulated by a complex network of transcription factors. The MEF2 family of transcription factors are important players in muscle development and differentiation.
MEF2 transcription factors regulate distinct gene programs in mammalian skeletal muscle differentiation.
Cell line
View SamplesThe aim of this analysis was to investigate the changes in the gene expression pattern of ex vivo cultured wildtype murine osteoclasts during the course of osteoclastogenic differentiation.
The Lysosomal Protein Arylsulfatase B Is a Key Enzyme Involved in Skeletal Turnover.
Sex, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Stability of gene expression and epigenetic profiles highlights the utility of patient-derived paediatric acute lymphoblastic leukaemia xenografts for investigating molecular mechanisms of drug resistance.
Sex
View SamplesBackground: Patient-derived tumour xenografts are an attractive model for preclinical testing of anti-cancer drugs. Insights into tumour biology and biomarkers predictive of responses to chemotherapeutic drugs can also be gained from investigating xenograft models. As a first step towards examining the equivalence of epigenetic profiles between xenografts and primary tumours in paediatric leukaemia, we performed genome-scale DNA methylation and gene expression profiling on a panel of 10 paediatric B-cell precursor acute lymphoblastic leukaemia (BCP-ALL) tumours that were stratified by prednisolone response. Results: We found high correlations in DNA methylation and gene expression profiles between matching primary and xenograft tumour samples with Pearsons correlation coefficients ranging between 0.85 and 0.98. In order to demonstrate the potential utility of epigenetic analyses in BCPALL xenografts, we identified DNA methylation biomarkers that correlated with prednisolone responsiveness of the original tumour samples. Differential methylation of CAPS2, ARHGAP21, ARX and HOXB6 were confirmed by locus specific analysis. We identified 20 genes showing an inverse relationship between DNA methylation and gene expression in association with prednisolone response. Pathway analysis of these genes implicated apoptosis, cell signalling and cell structure networks in prednisolone responsiveness. Conclusions: The findings of this study confirm the stability of epigenetic and gene expression profiles of paediatric BCP-ALL propagated in mouse xenograft models. Further, our preliminary investigation of prednisolone sensitivity highlights the utility of mouse xenograft models for preclinical development of novel drug regimens with parallel investigation of underlying gene expression and epigenetic responses associated with novel drug responses.
Stability of gene expression and epigenetic profiles highlights the utility of patient-derived paediatric acute lymphoblastic leukaemia xenografts for investigating molecular mechanisms of drug resistance.
Sex
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