RNA-seq analysis of T-ALL cells following FTO or ELK3 silencing
Ontology highlight
ABSTRACT: FTO serves as one of the demethylases for RNA N (6)-methyladenosine (m6A). ELK3 is responsible for encoding a member within the ETS-domain transcription factor family and the ternary complex factor (TCF) subfamily. To elucidate the roles and mechanisms of FTO and ELK3 in human T-cell acute lymphoblastic leukemia (T-ALL), we conducted RNA-seq analyses in KOPTK1 or CUTLL1 T-ALL cells following the silencing of FTO or ELK3
Project description:ELK3 is responsible for encoding a member within the ETS-domain transcription factor family and the ternary complex factor (TCF) subfamily.To identify downstream target genes directly regulated by ELK3 and reveal its critical role in T-ALL, we performed immunoprecipitation analysis using ELK3 antibodies in KOPTK1 cells
Project description:To identify transcripts directly regulated by FTO through m6A modification in T-ALL, we conducted m6A-seq after silencing FTO in KOPTK1 cells
Project description:Since m6A demethylases (FTO and ALKBH5) have been reported to be involved in pre-mRNA splicing regulation, we hypothesized that dynamic m6A distribution during mRNA maturation might involve removal of m6A in internal exons by FTO or ALKBH5 accompanied by splicing factors. To explore this we performed pull-down assays coupled with protein mass spectrometry.
Project description:Triple-negative breast cancer is a highly aggressive tumor subtype that lacks effective therapeutic targets. Here, we show that ELK3 is overexpressed in a subset of breast cancers, in particular basal-like and normal-like/claudin-low cell lines. Suppression of ELK3 in MDA-MB-231 cells led to transdifferentiation from an invasive mesenchymal phenotype to a non-invasive epithelial phenotype both in vitro and in vivo. Suppression of ELK3 results in the extensive changes in genome expression profiles. Among these, GATA3, a master suppressor of metastasis, was epigenetically activated and we found that suppression of GATA3 led to the restoration of migration and invasion. These results suggest that the ELK3-GATA3 axis is a major pathway that promotes metastasis of MDA-MB-231 cells. Retrovirus expressing shRNA of ELK3 was transduced into MDA-MB-231 cell line and stable cell line of which ELK3 is suppressed more than 50% was selected by the drug selection (Puromycin).
Project description:Single nucleotide polymorphisms in intron 1 of the fat mass and obesity-associated (FTO) gene were found to be associated with an increased risk of adult obesity. Enhanced FTO expression in mice leads to hyperphagia, increased fat mass, and higher body weight. Neuronal-specific FTOâ??deleted mice have an identical lean body weight phenotype to global FTO-deleted mice. The physiological role of adipose FTO in the homeostasis of energy regulation remains to be elucidated. We used microarrays to elucidate the metabolic pathways that are regulated by FTO in the white fat. FTO flox/flox and Adiponectin-cre FTO flox/flox (AFO) mice were fed with chow diet. White fat tissues from epididymal adipose pad were harvested under ad lib condition for RNA isolation. Three independent pools of FTO flox/flox and AFO mouse white fat RNA were included in the study.
Project description:The molecular response to hypoxia is a critical cellular process implicated in cancer, and a target for drug development. The activity of the major player, HIF1M-NM-1,M-BM- is regulated at different levels, including the transcriptional level by the Ets factor ELK3. The molecular mechanisms of this intimate transcriptional connection remain largely unknown. Whilst investigating global ELK3-chromatin interactions, we uncovered an unexpected connection that involves the microRNA hsa-miR-155-5p, a hypoxia-inducible oncomir that targets HIF1M-NM-1. One of the ELK3 chromatin binding sites, detected by Chromatin Immuno-Precipitation Sequencing (ChIP-seq) of normal Human Umbilical Vein Endothelial Cells (HUVEC), is located at the transcription start site of the MIR155HG genes that expresses hsa-miR-155-5p. We confirmed that ELK3 binds to this promoter by ChIP and QPCR. We showed that ELK3 and hsa-miR-155-5p form a double-negative regulatory loop. ELK3 depletion induced hsa-miR-155-5p expression, and hsa-miR-155-5p expression decreased ELK3 expression at the RNA level through a conserved target sequence in its 3M-bM-^@M-^Y-UTR. We further showed that the activities of hsa-miR-155-5p and ELK3 are functionally linked. Pathway analysis indicates that both factors are implicated in related processes, including cancer and angiogenesis. hsa-miR-155-5p expression and ELK3 depletion have similar effects on expression of known ELK3 target genes, and in-vitro angiogenesis and wound closure. Bioinformatic analysis of cancer RNA-seq data shows that hsa-miR-155-5p and ELK3 expression are significantly anti-correlated, as would be expected from hsa-miR-155-5p targeting ELK3 RNA. Hypoxia (0% oxygen) down-regulates ELK3 mRNA in a microRNA and hsa-miR-155-5p dependent manner. These results tie ELK3 into the hypoxia response pathway through an oncogenic microRNA and into a circuit implicated in the dynamics of the hypoxic response.M-BM- This crosstalk could be important in the development of new treatments for a range of pathologies. Examination of ELK3 DNA interactions in HUVEC cells under normal oxygen conditions
Project description:Triple-negative breast cancer is a highly aggressive tumor subtype that lacks effective therapeutic targets. Here, we show that ELK3 is overexpressed in a subset of breast cancers, in particular basal-like and normal-like/claudin-low cell lines. Suppression of ELK3 in MDA-MB-231 cells led to transdifferentiation from an invasive mesenchymal phenotype to a non-invasive epithelial phenotype both in vitro and in vivo. Suppression of ELK3 results in the extensive changes in genome expression profiles. Among these, GATA3, a master suppressor of metastasis, was epigenetically activated and we found that suppression of GATA3 led to the restoration of migration and invasion. These results suggest that the ELK3-GATA3 axis is a major pathway that promotes metastasis of MDA-MB-231 cells.
Project description:Here we use MeRIP-Seq to analyze global adenosine methylation (m6A) in mRNAs in the midbrain and striatum of Fto-deficient mice. We find that Fto deficiency leads to increased methylation within a subset of mRNAs important for neuronal signaling, including many within the dopaminergic signaling pathway. Collectively, our results show that Fto regulates demethylation of specific mRNAs in vivo, and this activity relates to control of dopaminergic transmission. Profiling of m6A in midbrain and striatum from FTO knockout mice
Project description:Background Triple-negative breast cancer (TNBC) is the most challenging subtype of breast cancer because of its aggressive behavior and the limited therapeutic strategies available. In the last decade, immunotherapy has become a promising treatment to prolong survival in advanced solid cancers including TNBC. However, the efficacy of immunotherapy in solid cancers remains limited because solid tumors contain few tumor-infiltrating lymphocytes. Methods A proteome profiler array was performed to identify secreted CXCL16 protein, the expression of which is regulated by ELK3 to control natural killer (NK) cell-mediated cytotoxicity. The correlation between ELK3 and CXCL16 was investigated by microarray and TCGA data analysis. NK cell cytotoxicity and migration assays were performed to examine the role of ELK3-CXCL16 in regulating the anticancer effect in TNBC. CXCL16-mediated NK cell recruitment and NK cell cytotoxicity were examined in an experimental metastasis mouse model and in an MDA-MB231 orthotopic mouse model. Results We show that targeting the ETS transcription factor ELK3 recruits immune cells including NK cells into tumors via the chemotactic activity of the chemokine. ELK3 depletion upregulated CXCL16 expression, thereby inducing NK cell recruitment to tumors and increasing NK cell cytotoxicity in TNBC . In silico analysis showed that ELK3 is negatively correlated with CXCL16 expression in breast cancer patient samples. Low expression of ELK3 and high expression of CXCL16 were associated with a better prognosis. Low expression of ELK3 and high expression of CXCL16 were associated with increased expression of NK cell-related genes. Conclusions The ELK3-CXCL16 axis regulates NK cell recruitment and increases NK cell cytotoxicity, suggesting that targeting the ELK3 gene could be an adjuvant strategy for increasing the efficacy of immunotherapy in TNBC.