Project description:Gene expression profile of p53 knockdown MSCs or p53 knockdown+TERT MSCs was compared with that of control MSCs. Our data show p53 knockdown prolongs the lifespan of MSCs, and a combination of p53 knockdown and TERT overexpression is sufficient to immortalize MSCs. The results provide important information about the molecular basis underlying p53 knockdown in MSCs and immortalization-related genes of MSCs. Total RNA obtained from p53 knockdown MSCs or p53 knockdown+TERT MSCs from three patients were compared with control MSCs.
Project description:Gene expression profile of p53 knockdown MSCs or p53 knockdown+TERT MSCs was compared with that of control MSCs. Our data show p53 knockdown prolongs the lifespan of MSCs, and a combination of p53 knockdown and TERT overexpression is sufficient to immortalize MSCs. The results provide important information about the molecular basis underlying p53 knockdown in MSCs and immortalization-related genes of MSCs.
Project description:H3K4me3 changes during immortalization of breast cells. The aim of the study was to determine whether differential epigentic state of TERT gene is involved in immortalization of breast cells.
Project description:H3K27me3 changes during immortalization of breast cells. The aim of the study was to determine whether differential epigentic state of TERT gene is involved in immortalization of breast cells.
Project description:Pluripotent stem cells evade replicative senescence, whereas other primary cells lose their proliferation and differentiation potential after a limited number of cell divisions M-bM-^@M-^S and this is accompanied by specific senescence-associated DNA methylation (SA-DNAm) changes. Here, we investigate SA-DNAm changes in mesenchymal stromal cells (MSC) upon long-term culture, irradiation-induced senescence, immortalization and reprogramming into induced pluripotent stem cells (iPSC) using high density HumanMethylation450 BeadChips. SA-DNAm changes are highly reproducible and occur particularly in intergenic and non-promoter regions of developmental genes. We demonstrate that ionizing irradiation, although associated with a very similar senescence phenotype, does not affect SA-DNAm. Furthermore, overexpression of the catalytic subunit of the human telomerase (TERT) or conditional immortalization with a doxycycline-inducible system (TERT and SV40 TAg) result in telomere extension but do not influence SA-DNAm. In contrast, we demonstrate that reprogramming into iPSC prevented SA-DNAm changes. Our results indicate that replicative senescence is associated with an epigenetically controlled process which stalls cells in a particular differentiated state, whereas irradiation-induced senescence and immortalization are not causally related to this process. Absence of SA-DNAm in pluripotent cells may play a central role for their escape from cellular senescence. Samples were hybridised to the Illumina Infinium 450k Human Methylation Beadchip
Project description:Evaluation of 2HG and a-ketoglutarate in tumor neurospheres (NS) genertated from the mice brain tumors haboring specific genetic lesions: NRAS overexpression, p53 knockdown plus or minus IDH1 mutated and ATRX knockdown.
Project description:DNA methylation changes during immortalization of breast cells. The aim of the study was to determine whether differential epigentic state of TERT gene is involved in immortalization of breast cells.
Project description:Our study proposes a precise mechanistic classification of clinical neuroblastoma phenotypes that is based on telomere maintenance mechanisms and RAS or p53 pathway mutations. A crucial factor in telomere maintenance is overexpression of TERT. We therefore determined a TERT expression threshold to identify MYCN-WT TERT-WT tumors whose TERT mRNA levels are comparable to those of tumors bearing MYCN or TERT alterations.
Project description:Our study proposes a precise mechanistic classification of clinical neuroblastoma phenotypes that is based on telomere maintenance mechanisms and RAS or p53 pathway mutations. A crucial factor in telomere maintenance is overexpression of TERT. We therefore determined a TERT expression threshold to identify MYCNWT TERTWT tumors whose TERT mRNA levels are comparable to those of tumors bearing MYCN or TERT alterations.
