Project description:HEK293T cells were transfected with plasmids expressing a control siRNA or a siRNA especific for CHD6 protein. 48H post-transfection, total RNA was isolated and used for transcriptome analysis. Four biological replicates carried out by triplicate were used.
Project description:Members of the chromodomain-helicase-DNA binding (CHD) protein family are chromatin remodelers implicated in human pathologies, with CHD6 being one of its least studied members. We discovered a de novo CHD6 missense mutation in a patient clinically presenting the rare Hallermann-Streiff syndrome (HSS). We used genome editing to generate isogenic iPSC lines and model HSS in relevant cell types. By combining genomics with functional in vivo and in vitro assays, we show that CHD6 binds a cohort of autophagy and stress response genes across cell types. The HSS mutation affects CHD6 protein folding and impairs its ability to recruit co-remodelers in response to DNA damage or autophagy stimulation. This leads to accumulation of DNA damage burden and senescence-like phenotypes. We therefore uncovered a molecular mechanism explaining HSS onset via chromatin control of autophagic flux and genotoxic stress surveillance.
Project description:Purpose: Study of the role of CHD6 linking nucleosome ejection in castration-resistant prostate cancer(CRPC) Method: The expression of CHD6 or E2F1 was silenced by 2 shRNAs (3 replicates) targeted at CHD6 or E2F1 in C4-2 cells, scramble RNA as control. mRNA profiles and genome-wide chromatin-state maps were generated by deep sequencing. CHD6 and IgG ChIP was conducted in C4-2 cells. MNase before and after CHD6-silenced was conducted in C4-2 cells. Results: E2F1 and E2F1 downstream genes were significantly down regulated by CHD6 knockdown. The binding of CHD6 on chromatin is required for nucleosome eviction in transcriptional activation of oncogenic pathways.
Project description:Members of the Chromodomain-Helicase-DNA binding (CHD) protein family are chromatin remodelers critically implicated in human pathologies. CHD6 is the least studied member of this family, and we were motivated to dissect its in-cell roles by discovering a mutated CHD6 allele in a patient suffering from the rare Hallermann-Streiff premature aging syndrome (HSS). We generated isogenic iPSC lines carrying (or not) this single point mutation in the CHD6 SANT/SLIDE domain, which allow studying HSS-relevant cell identities. Using these lines, we show for the first time that CHD6 binds the promoters of a cohort of autophagy and stress response genes across cell types. This CHD6 mutation impairs its ability to recruit co-factors and regulate genes in response to DNA damage and autophagy stimulation, thus leading to accumulation of unresolved DNA damage burden. By combining genomics and functional assays, we describe a molecular mechanism underlying chromatin control of autophagic flux and genotoxic stress surveillance that is broadly applicable to human cell types and can explain HSS establishment.
Project description:Colorectal cancer is one of the most common cancers. Cancer cells are highly dependent on dysregulated gene expression to support their uncontrolled growth and high energy needs. The expression of gene encoding chromodomain helicase DNA binding protein 6 (CHD6) is frequently altered in tumor tissues of colorectal cancer patients.We performed transcriptomic analysis to identify the differentially expressed genes between control and CHD6 KD HCT116.
Project description:Members of the chromodomain-helicase-DNA binding (CHD) protein family are chromatin remodelers critically implicated in human pathologies, with CHD6 being one of its least studied members. Here, we discovered a de novo CHD6 missense mutation in a patient clinically presenting the rare Hallermann-Streiff syndrome (HSS). We used genome editing to generate isogenic iPSC lines and model HSS in relevant cell types. We show that CHD6 binds a cohort of autophagy and stress response genes across cell types. The HSS-mutation affects CHD6 protein folding and impairs its ability to recruit co-factors in response to DNA damage or autophagy stimulation. This leads to an accumulation of DNA damage burden and to senescence-like phenotypes. By combining genomics and functional assays, we describe for the first time a molecular mechanism for the chromatin control of autophagic flux and genotoxic stress surveillance that applies broadly to human cell types and explains HSS onset.
Project description:Members of the Chromodomain-Helicase-DNA binding (CHD) protein family are chromatin remodelers critically implicated in human pathologies. CHD6 is the least studied member of this family, and we were motivated to dissect its in-cell roles by discovering a mutated CHD6 allele in a patient suffering from the rare Hallermann-Streiff premature aging syndrome (HSS). We generated isogenic iPSC lines carrying (or not) this single point mutation in the CHD6 SANT/SLIDE domain, which allow studying HSS-relevant cell identities. Using these lines, we show for the first time that CHD6 binds the promoters of a cohort of autophagy and stress response genes across cell types. This CHD6 mutation impairs its ability to recruit co-factors and regulate genes in response to DNA damage and autophagy stimulation, thus leading to accumulation of unresolved DNA damage burden. By combining genomics and functional assays, we describe a molecular mechanism underlying chromatin control of autophagic flux and genotoxic stress surveillance that is broadly applicable to human cell types and can explain HSS establishment.
Project description:How various ATP-dependent chromatin remodellers bind to nucleosomes to regulate transcription is not well defined in mammalian cells. Here, we present genome-wide remodeller-interacting nucleosome profiles for Chd1, Chd2, Chd4, Chd6, Chd8, Chd9, Brg1 and Ep400 in mouse embryonic stem (ES) cells. These remodellers bind to nucleosomes at specific positions, either at one or both nucleosomes that flank each side of nucleosome-free promoter regions (NFRs), at enhancer elements, or within gene bodies. At promoters, bidirectional transcription commonly initiates on either side of remodeller-bound nucleosomes. Transcriptome analysis upon remodeller depletion reveals reciprocal mechanisms of transcriptional regulation by remodellers. At active genes, certain remodellers are positive regulators of transcription, whereas others act as repressors. At bivalent genes, which are bound by repressive Polycomb complexes, the same remodellers act in the opposite way. Together, these findings reveal how remodellers integrate promoter nucleosomal architecture to regulate ES cell transcription programs.
Project description:The primary objective of this prospective observational study is to characterize the gut and oral microbiome as well as the whole blood transcriptome in gastrointestinal cancer patients and correlate these findings with cancer type, treatment efficacy and toxicity. Participants will be recruited from existing clinical sites only, no additional clinical sites are needed.