DAC for study Hominin-specific NOTCH2 paralogs expand human cortical neurogenesis through regulation of Delta/Notch interactions.
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ABSTRACT:
PROVIDER: EGAC00001000816 | EGA |
REPOSITORIES: EGA
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Project description:The cerebral cortex underwent rapid expansion and increased complexity during recent hominid evolution. Gene duplications constitute a major evolutionary force, but their impact on human brain development remains unclear. Using tailored RNA sequencing (RNA-seq), we profiled the spatial and temporal expression of hominid-specific duplicated (HS) genes in the human fetal cortex and identified a repertoire of 35 HS genes displaying robust and dynamic patterns during cortical neurogenesis. Among them NOTCH2NL, human-specific paralogs of the NOTCH2 receptor, stood out for their ability to promote cortical progenitor maintenance. NOTCH2NL promote the clonal expansion of human cortical progenitors, ultimately leading to higher neuronal output. At the molecular level, NOTCH2NL function by activating the Notch pathway through inhibition of cis Delta/Notch interactions. Our study uncovers a large repertoire of recently evolved genes active during human corticogenesis and reveals how human-specific NOTCH paralogs may have contributed to the expansion of the human cortex.
| S-EPMC6092419 | biostudies-literature
Project description:The human cerebral cortex has undergone rapid expansion and increased complexity during recent evolution. Hominid-specific gene duplications represent a major driving force of evolution, but their impact on human brain evolution remains unclear. Using tailored RNA sequencing (RNAseq), we profiled the spatial and temporal expression of Hominid-specific duplicated (HS) genes in the human fetal cortex, leading to the identification of a repertoire of 36 HS genes displaying robust and dynamic patterns during cortical neurogenesis. Among these we focused on NOTCH2NL, previously uncharacterized HS paralogs of NOTCH2. NOTCH2NL promote the clonal expansion of human cortical progenitors by increasing self-renewal, ultimately leading to higher neuronal output. NOTCH2NL function by activating the Notch pathway, through inhibition of Delta/Notch interactions. Our study uncovers a large repertoire of recently evolved genes linking genomic evolution to human brain development, and reveals how hominin-specific NOTCH paralogs may have contributed to the expansion of the human cortex.
The dataset contains raw sequences (FASTQ files) from the Illumina 2x150bp paired-end RNA sequencing profiles of 11 fetal human brain samples at 7, 9, 12, 15 and 21 gestational weeks.
| EGAS00001002798 | EGA
Project description:The human cerebral cortex underwent rapid enlargement and complexification during recent evolution. Hominid-specific (HS) genes arising from genomic duplications may be involved, but it remains unclear how much and which HS genes contribute to human brain development. Using tailored RNAseq profiling, we identify a repertoire of >60 HS genes that display robust and dynamic expression during human fetal corticogenesis. Among these, Notch2NL genes stood out as human-specific Notch2 paralogs that promotes cortical progenitor maintenance. Clonal analyses of human cortical progenitors revealed that Notch2NL promotes their expansion by increasing self-renewal, ultimately leading to higher clonal neuronal output. Notch2NL acts by direct activation of the Notch pathway, through cell-autonomous inhibition of Delta/Notch interactions. Our data identify a large repertoire of newly evolved genes linking human brain development and evolution, and indicate how human-specific Notch paralogs may have contributed to the expansion of the human brain.
2018-04-06 | E-MTAB-6232 | biostudies-arrayexpress
Project description:Reversal of gene promoter DNA hypermethylation and associated abnormal gene silencing is an attractive approach to cancer therapy. The DNA methylation inhibitor, decitabine (5-aza-2'-deoxycitidine), is proving efficacious for hematological neoplasms especially at lower, less toxic, doses. Experimentally, high doses induce rapid DNA damage and cytotoxicity, but these may not explain the prolonged time to response seen in patients. Transient exposure of leukemic and solid tumor cells to clinically-relevant nanomolar doses, without causing immediate cytotoxicity or apoptosis, produces sustained reduced tumorigenicity, and for leukemia cells, diminished long-term self-renewal. These effects appear triggered by cellular reprogramming and include sustained decreases in promoter DNA methylation with associated gene re-expression, and anti-tumor changes in multiple key cellular regulatory pathways, most of which are high priority targets for pharmacologic anti-cancer strategies. Thus, low dose decitabine regimens appear to have broad applicability for cancer management. [Gene expression profiling] Leukemia cell lines Kasumi-1 and KG1A are treated with 10nM DAC during 72 hours and gene expression was assayed at day 3, 7 and 14 after the start of the treatment. Appropriate mock treated samples were used as control in each case. In addition, Kasumi-1 cells were also treated with a higher dose of DAC (500nM), 100nM ARA-C and 300 nM TSA, again controlled against mock treated Kasumi-1 cells, to separate dose and agent dependent effects. MCF7 was studied as an example of a solid tumor cell line. Therefore MCF7 cells were treated with 100nM DAC and results were assayed at day 1, day 3 and day 10. [Methylation profiling] The effects of the demethylating agent DAC were studied in the leukemia cell line Kasumi-1 over a 28 day time course. Intermediate time points were studied at days 3, 7, 14 and 21. These results were verfied in KG1A and KG1 leukemia cell lines, at one selected time point. The effects on one primary sample were also studied. Four normal leukemia samples (PL1, 2, 4 and 5) were used as general controls. The effect of DAC was compared to ARA-C, TSA. Both mock treated and day 3 DAC treated Kasumi-1 cells were repeated. These results were verified at one selected time point for the DAC treated MCF7 breast cancer cell line.
2012-03-21 | E-GEOD-20945 | biostudies-arrayexpress
Project description:Genetic changes causing brain size expansion in human evolution have remained elusive. Notch signaling is essential for radial glia stem cell proliferation and is a determinant of neuronal number in the mammalian cortex. We find that three paralogs of human-specific NOTCH2NL are highly expressed in radial glia. Functional analysis reveals that different alleles of NOTCH2NL have varying potencies to enhance Notch signaling by interacting directly with NOTCH receptors. Consistent with a role in Notch signaling, NOTCH2NL ectopic expression delays differentiation of neuronal progenitors, while deletion accelerates differentiation into cortical neurons. Furthermore, NOTCH2NL genes provide the breakpoints in 1q21.1 distal deletion/duplication syndrome, where duplications are associated with macrocephaly and autism and deletions with microcephaly and schizophrenia. Thus, the emergence of human-specific NOTCH2NL genes may have contributed to the rapid evolution of the larger human neocortex, accompanied by loss of genomic stability at the 1q21.1 locus and resulting recurrent neurodevelopmental disorders.
| S-EPMC5986104 | biostudies-literature
Project description:We found frequent epigenetic silencing of microRNA-34b/c in human colorectal cancer. Introduction of miR-34b/c into a colorectal cancer cell line induced significant changes in gene expression profile. We also found overlap between the genes downregulated by miR-34b/c and those downregulated by DAC. Keywords: dose response A colorecal cancer cell line HCT116 was transfected with miR-34b or -c precursor or negative control. Also, HCT116 was treated with 5-aza-2'-deoxycytidine (DAC) or mock. Genes up- or downregulated by miR-34b/c and those by DAC was compared.
2008-04-30 | E-GEOD-10455 | biostudies-arrayexpress
Project description:Melanoma progression model:DAC-mediated gene expression Keywords: other
2005-07-20 | GSE1793 | GEO
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Project description:Aberrant expression of microRNA (miRNA) has been reported in various cancers. To clarify the role of miRNA in gastric carcinogenesis, we performed miRNA microarray analysis and investigated expressional changes of miRNAs in a 5-aza-2'-deoxycytidine (DAC)-treated gastric cancer cell line, KATO-ІІІ.
2010-01-20 | GSE16006 | GEO