Autophagy mediates the mitotic senescence transition
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ABSTRACT: ER:RAS-G12V expressing IMR90 cells were given 100nM 4-OHT and assessed for transcriptional profiling at various time points. IMR90 cells expressing a 4-hydroxytamoxifen (4-OHT) inducible estrogen receptor (ER)-coupled RAS-G12V (ER:RAS-G12V) were given 100nM 4-OHT for these eight time points (0, 2, 8, 24hrs, 2, 4, 6 and 8days) then analysed for transcriptional profiling using the illumina expression array platform (human-6 v2 Expression BeadChips). There were three biological replicates (batch A, B and D) for each of the time points.
Project description:ER:RAS-G12V expressing IMR90 cells were treated with either 100nM 4-OHT or 40uM Celecoxib or both for 6 days leading to RAS-induced senescence (RIS) with or without COX2 inhibition.
Project description:ER:RAS-G12V expressing IMR90 cells were transduced with N1ICD-containing or control vectors before treatment with either 100nM 4-OHT or vehicle for 6 days leading to Notch-induced senescence (NIS), RAS-induced senescence (RIS) or combined Notch and Ras-induced senescence (RNIS).
Project description:ER:RAS-G12V expressing IMR90 cells were treated with either 100nM 4-OHT for 6 days or 100uM Etoposide for 2 days, followed by further culture for 5 days, leading to RAS-induced senescence (RIS) and DNA-damage induced senescence (DDIS) respectively.
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
Project description:To examine effects of NMT inhibition on senescence transcriptional signatures we treated IMR90 ER:RAS cells with either IMP1088 (300nM) or DDD86481 (1.5uM) for 72h 7 days after induction with 4-OHT treatment. Transcriptional analysis was performed 3 days after drug treatment and 10 days after senescence induction.
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
Project description:Protein synthesis and autophagic degradation are regulated in an opposite manner by mammalian target of rapamycin (mTOR), whereas under certain conditions it would be beneficial if they occured in unison to handle rapid protein turnover. We observed a distinct cellular compartment at the trans-side of the Golgi apparatus, the ‘TOR-autophagy spatial coupling compartment’ (TASCC), where (auto)lysosomes and mTOR accumulated during Ras-induced senescence. mTOR recruitment to the TASCC was amino acid- and Rag guanosine triphosphatase (GTPase)-dependent, and disruption of mTOR localization to the TASCC suppressed interleukin-6/8 synthesis. TASCC-formation was observed during macrophage differentiation and in glomerular podocytes; both displayed increased protein secretion. The spatial coupling of cells’ catabolic and anabolic machinery could augment their respective functions and facilitate the mass synthesis of secretory proteins. To compare gene expression profile between growing and oncogenic Ras induced senescence, 4OHT inducible ER:H-RasV12 was stably expressed in IMR90 human diploid fibroblasts. Total RNA was isolated from day 0 and day 4 after 4OHT addition. There were 3 biological replicates for each of day0 and day 4 timepoints.
Project description:Cellular senescence can be transmitted to neighbouring cells in a paracrine manner through different mechanisms, including soluble factors released by senescent cells. To understand the dynamic regulation of paracrine senescence, here we investigated gene expression profiles in normal human fibroblasts (IMR90) exposed to conditioned medium generated by an inducible model of fibroblast Oncogene-Induced Senescence (IMR90-ER:RAS) at different time points after induction of senescence.
Project description:The expansion of repressive epigenetic marks has been implicated in heterochromatin formation during embryonic development, but the general applicability of this mechanism is unclear. Here we show that nuclear rearrangement of repressive histone marks H3K9me3 and H3K27me3 into non-overlapping structural layers characterizes senescence-associated heterochromatic foci (SAHF) formation in human fibroblasts. However, the global landscape of these repressive marks remains unchanged upon SAHF formation, suggesting that in somatic cells heterochromatin can be formed through the spatial repositioning of pre-existing repressively marked histones. This model is reinforced by the correlation of pre-senescent replication timing with both the subsequent layered structure of SAHFs and the global landscape of the repressive marks, allowing us to integrate microscopic and genomic information. Furthermore, modulation of SAHF structure does not affect the occupancy of these repressive marks nor vice versa. These experiments reveal that high-order heterochromatin formation and epigenetic remodeling of the genome can be discrete events. ChIP-seq for different histone marks in both growing and Ras-induced senescent fibroblasts, in the presence or absence of certain sh-RNAs K9me3Grow2.bed (growing) Chip Seq Analysis of H3K9me3 in ER:Ras expressing IMR90 human diploid fibroblasts d6 4OHT K9me3Sen2.bed (senescent) Chip Seq Analysis of H3K9me3 in ER:Ras expressing IMR90 human diploid fibroblasts with no treatment K9me2Grow3.bed (growing) Chip Seq Analysis of H3K9me2 in ER:Ras expressing IMR90 human diploid fibroblasts with no treatment K9me2Sen3.bed (senescent) Chip Seq Analysis of H3K9me2 in ER:Ras expressing IMR90 human diploid fibroblasts d6 4OHT K27me3Sen3.bed (senescent) Chip Seq Analysis of H3K27me3 in ER:Ras expressing IMR90 human diploid fibroblasts d6 4OHT K27me3Grow2.bed (growing) Chip Seq Analysis of H3K27me3 in ER:Ras expressing IMR90 human diploid fibroblasts with no treatment K36me3Grow2.bed (growing) Chip Seq Analysis of H3K36me3 in ER:Ras expressing IMR90 human diploid fibroblasts with no treatment K36me3Sen2.bed (senescent) Chip Seq Analysis of H3K36me3 in ER:Ras expressing IMR90 human diploid fibroblasts d6 4OHT K4me3Grow2.bed (growing) Chip Seq Analysis of H3K4me3 in ER:Ras expressing IMR90 human diploid fibroblasts with no treatment K4me3Sen3.bed (senescent) Chip Seq Analysis of H3K4me3 in ER:Ras expressing IMR90 human diploid fibroblasts d6 4OHT