Senescence in WI-38 cell context was induce by RASv12 over expression Cellular senescence is a permanent cell cycle arrest that is triggered by cancer- initiating or promoting events in mammalian cells and is now considered a major tumour suppressor mechanism. Here, we did a transcriptomic analysis and compared WI-38 contol wich is a human fibroblaste cell line and WI-38 that overexpressed RASv12 a G protein that induce senescence. The goal of our project is to compare transciptomic profile of human growing fibroblast (WI-38 control) and senescent human fibroblast (WI-38 OERAS)
Senescence is an endogenous trigger for microRNA-directed transcriptional gene silencing in human cells.
Specimen part
View SamplesIn humans, there are four Ago proteins (Ago1–4) and AGO1- and 2 were previously implicated in TGS induced by exogenous siRNAs and microRNAs (miRs) directed against gene promoter transcripts via promotion of changes in histone covalent modifications and DNA methylation. Not-with-standing, many mechanistic details of this process remain poorly defined in human cells, and very little is known about the identity of possible endogenous signals, which may drive this process in human cells. Given the evolutionary conserved role of siRNAs and AGO proteins in TGS and heterochromatin formation, we set out to analyse their possible involvement in senesence-associated repression of E2F target genes. To obtain a detailed picture of AGO-immunoprecipitating miRs (RIP) in senescent cells, we used next-generation sequencing (NGS)(RIP-Seq). We also included histone H3 dimethylated on lysine 9 (H3K9me2) in this analysis to assign potential AGO2-interacting miRs to a repressive chromatin state and unfractionated, cellular RNA from senescent cells for normalisation. Overall design: Determination of AGO AGO-immunoprecipitating miRs in WI-38 senescent human fibroblast
Senescence is an endogenous trigger for microRNA-directed transcriptional gene silencing in human cells.
No sample metadata fields
View SamplesThe transcriptional coactivator ANGUSTIFOLIA 3 (AN3) stimulates cell proliferation during Arabidopsis leaf development, but the molecular mechanism is largely unknown. We show here that inducible nuclear localization of AN3 during initial leaf growth results in differential expression of important transcriptional regulators, including GROWTH REGULATING FACTORs (GRFs). Chromatin purification further revealed the presence of AN3 at the loci of GRF5, GRF6, CYTOKININ RESPONSE FACTOR 2 (CRF2), CONSTANS-LIKE 5 (COL5), HECATE 1 (HEC1), and ARABIDOPSIS RESPONSE REGULATOR 4 (ARR4). Tandem affinity purification of protein complexes using AN3 as bait identified plant SWITCH/SUCROSE NONFERMENTING (SWI/SNF) chromatin remodeling complexes formed around the ATPases BRAHMA (BRM) or SPLAYED (SYD). Moreover, SWI/SNF ASSOCIATED PROTEIN 73B (SWP73B) is recruited by AN3 to the promoter of GRF5, GRF3, COL5, and ARR4, and both SWP73B and BRM occupy the HEC1 promoter. Furthermore, we show that AN3 and BRM genetically interact. The data indicate that AN3 associates with chromatin remodelers to regulate transcription. In addition, modification of SWI3C expression levels increases leaf size, underlining the importance of chromatin dynamics for growth regulation. Our results place the SWI/SNF-AN3 module as a major player at the transition from cell proliferation to cell differentiation in a developing leaf.
ANGUSTIFOLIA3 binds to SWI/SNF chromatin remodeling complexes to regulate transcription during Arabidopsis leaf development.
Specimen part, Time
View SamplesPolarity defects are a hallmark of most carcinomas. Cells from invasive micropapillary carcinomas (IMPCs) of the breast are characterized by a striking cell polarity inversion and represent a good model for the analysis of polarity abnormalities. We have performed an in-depth investigation of polarity alterations in 24 IMPCs, compared with invasive carcinomas of no special type (ICNST).
LIN7A is a major determinant of cell-polarity defects in breast carcinomas.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Medullary Breast Carcinoma, a Triple-Negative Breast Cancer Associated with BCLG Overexpression.
Disease, Disease stage
View SamplesGene expression was compared between medullary breast carcinoma (MBC) and non medullary basal-like breast carcinoma (non-MBC BLC).
Medullary Breast Carcinoma, a Triple-Negative Breast Cancer Associated with BCLG Overexpression.
Disease, Disease stage
View SamplesDefective Hippo/YAP signaling in the liver results in tissue overgrowth and development of hepatocellular carcinoma (HCC). Here, we uncover mechanisms of YAP-mediated hepatocyte reprogramming and HCC pathogenesis. We show that YAP functions as a rheostat maintaining metabolic specialization, differentiation and quiescence within the hepatocyte compartment. Importantly, treatment with siRNA-lipid nanoparticles (siRNA-LNPs) targeting YAP restores hepatocyte differentiation and causes pronounced tumor regression in a genetically engineered mouse HCC model (mice with liver-specific Mst1/Mst2 double knockout). Furthermore, YAP targets are enriched in an aggressive human HCC subtype characterized by a proliferative signature and absence of CTNNB1 mutations. Thus, our work reveals Hippo signaling as a key regulator of positional identity of hepatocytes, supports targeting YAP using siRNA-LNPs as a paradigm of differentiation-based therapy, and identifies an HCC subtype potentially responsive to this approach. Overall design: Mice with liver-specific Mst1/Mst2 double-knockout (Adeno-Cre injected Mst1-/-; Mst2Flox/Flox mice) were monitored for the formation of HCC by ultrasound imaging. Animals were then randomized to be treated by intravenous injection of either siYap-LNPs or siLuciferase-LNPs for a period of 9 days.
YAP Inhibition Restores Hepatocyte Differentiation in Advanced HCC, Leading to Tumor Regression.
No sample metadata fields
View SamplesCNBP is a eukaryote-conserved nucleic-acid binding protein required in mammals for embryonic development. It contains seven CCHC-type zinc-finger domains and was suggested to act as a nucleic acid chaperone, as well as a transcription factor. Here, we identify all CNBP isoforms as cytoplasmic messenger RNA (mRNA)-binding proteins. Using Photoactivatable Ribonucleoside Enhanced Cross-linking and Immunoprecipitation, we mapped its binding sites on RNA at nucleotide-level resolution on a genome-wide scale and find that CNBP interacted with 3961 mRNAs in human cell lines, preferentially at a G-rich motif close to the AUG start codon on mature mRNAs. Loss- and gain-of-function analyses coupled with system-wide RNA and protein quantification revealed that CNBP did not affect RNA abundance, but rather promoted translation of its targets. This is consistent with an RNA chaperone function of CNBP helping to resolve secondary structures, thus promoting translation. Overall design: CNBP protein knockdown and RNA-seq
The Human CCHC-type Zinc Finger Nucleic Acid-Binding Protein Binds G-Rich Elements in Target mRNA Coding Sequences and Promotes Translation.
No sample metadata fields
View SamplesThe tumorigenicity of human pluripotent stem cells (hPSCs) is a major safety concern for their application in regenerative medicine. Here we identify the tight-junction protein Claudin-6 as a specific cell surface marker of hPSCs that can be used to selectively remove Claudin-6-positive cells from mixed cultures. We show that Claudin-6 is absent in adult tissues but highly expressed in undifferentiated cells, where it is dispensable for hPSC survival and self-renewal. We use three different strategies to remove Claudin-6-positive cells from mixed populations: an antibody against Claudin-6; a cytotoxin-conjugated antibody that selectively targets undifferentiated cells; and clostridium perfringens enterotoxin, a toxin that binds several Claudins, including Claudin-6, and efficiently kills undifferentiated cells, thus eliminating the tumorigenic potential of hPSC-containing cultures. This work provides a proof of concept for the use of Claudin-6 to eliminate residual undifferentiated hPSCs from culture, highlighting a strategy that may increase the safety of hPSC-based cell therapies.
Immunologic and chemical targeting of the tight-junction protein Claudin-6 eliminates tumorigenic human pluripotent stem cells.
Specimen part, Cell line
View SamplesPluripotent-specific inhibitors (PluriSIns) make a powerful tool for studying the mechanisms that control the survival of human pluripotent stem cells (hPSCs). Here we characterize PluriSIn#2 as a novel selective indirect inhibitor of topoisomerase II alpha (TOP2A). We find that TOP2A is uniquely expressed in undifferentiated hPSCs, and that its inhibition results in their rapid cell death. These findings reveal a dependency of hPSCs on the activity of TOP2A, which can be harnessed for their selective elimination from culture.
Brief reports: Controlling the survival of human pluripotent stem cells by small molecule-based targeting of topoisomerase II alpha.
Specimen part, Cell line, Treatment
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