Project description:IMR90 cells were passaged until replicative senescence and compared with proliferating cells. We used RNA-Seq to detail the global programme of gene expression in human IMR90 replicative induced senescence
Project description:Mammalian SIRT1 is a central regulator of metabolism and aging. This project is to analyze global phosphorylation levels of mammalian SIRT1 in proliferating and senescence states using human lung fibroblast IMR90, in order to explore the post-translational regulation of SIRT1 protein upon cellular senescence and its potential roles in the regulatory mechanisms of SIRT1 homeostasis.
Project description:Total RNA was isolated from proliferating and senescent IMR90 cells to compare gene-expression to the changes in nucleolus-association in proliferating and senescent IMR90 cells.
Project description:Transcription profiling from human primary fibroblasts as they progress into senescence. Samples were taken early population doubling onwards until cells reached replicative senescence and stopped dividing. Population doubling values are contained in Characteristics[generation] column.
Project description:RNAseq replicate in Proliferating and Senescent IMR90s We used RNAseq to examine RNA levels in human IMR90 replicative senescence (RS)
Project description:Cellular senescence is a stable proliferation arrest associated with an altered secretory pathway, the Senescence-Associated Secretory Phenotype (SASP). However, cellular senescence is initiated by diverse molecular triggers, such as activated oncogenes and shortened telomeres, and is associated with varied and complex physiological endpoints, such as tumor suppression and tissue aging. The extent to which distinct triggers activate divergent modes of senescence that might be associated with different physiological endpoints is largely unknown. To begin to address this, we performed gene expression profiling to compare the senescence programs associated with two different modes of senescence, oncogene-induced senescence (OIS) and replicative senescence (RS [in part caused by shortened telomeres]). While both OIS and RS are associated with many common changes in gene expression compared to control proliferating cells, they also exhibit substantial differences. These results are discussed in light of potential physiological consequences, tumor suppression and aging. We used microarrays to detail the global programme of gene expression after oncogene induced senescence.
Project description:H3K9me3 ChIPseq in Proliferating and Senescent IMR90s We used ChIP-seq to examine the global binding of H3K9me3 in human IMR90 replicative senescence (RS) and oncogene-induced (OIS)
Project description:Cellular senescence is a stable proliferation arrest associated with an altered secretory pathway, the Senescence-Associated Secretory Phenotype (SASP). However, cellular senescence is initiated by diverse molecular triggers, such as activated oncogenes and shortened telomeres, and is associated with varied and complex physiological endpoints, such as tumor suppression and tissue aging. The extent to which distinct triggers activate divergent modes of senescence that might be associated with different physiological endpoints is largely unknown. To begin to address this, we performed gene expression profiling to compare the senescence programs associated with two different modes of senescence, oncogene-induced senescence (OIS) and replicative senescence (RS [in part caused by shortened telomeres]). While both OIS and RS are associated with many common changes in gene expression compared to control proliferating cells, they also exhibit substantial differences. These results are discussed in light of potential physiological consequences, tumor suppression and aging.
Project description:Altered DNA methylation and associated destabilization of genome integrity and function is a hallmark of cancer. Replicative senescence imposes a limit on proliferative potential that all cancer cells must bypass. Compared to proliferating cells, senescent cells exhibit marked chromatin re-organization. Here we show by whole-genome single-nucleotide bisulfite sequencing that replicative senescent human cells exhibit widespread alterations in their DNA methylome. These changes are linked to mislocalization of the maintenance DNA methyltransferase (DNMT1) in cells approaching senescence, altered replication-coupled DNA methylation and de-repression of repetitive satellite sequences. Deficiency of DNMT1 triggers chromatin changes characteristic of senescence and expression of satellite sequences. Most importantly, but paradoxically, gains and losses of methylation in replicative senescence are similar to those in cancer, and this M-bM-^@M-^XreprogrammedM-bM-^@M-^Y methylation landscape is largely retained when cells escape or bypass senescence. In sum, altered regulation of DNMT1 in cells approaching replicative senescence contributes to changes in chromatin structure and function. Consequently, if senescent cells escape the proliferative barrier, they already harbor epigenetic changes likely to promote malignancy. Examination of methylation status in IMR90 cells
Project description:IMR90 cells were infected with pLNC-RAS:ER (from Jesus Gil lab) with retroviral gene transfer. Infected cells were drug selected G418. The cells were induced either with ethanol as control or with 100nM final conc 4-hydroxytamoxifen (sigma H7904) for ectopic expression of protein We used RNA-Seq to detail the global programme of gene expression in human IMR90 oncogene induced senescence