Project description:Stat3-binding promoters in human ESCC and CAFs Investigation of the critical gene promoters binding by pStat3 between ESCC cells and cancer-associated fibroblasts (CAFs).
Project description:To try to identify the mechanism of STAT3âs indirect action we have used a genomic approach to map the binding sites of STAT3 within the genome and also used RNA-seq technology to map the changes in RNA expression and transcript isoforms in response to IL-10. Examination of STAT3 binding by ChIP-seq in Unstimulated and IL-10 treated peritoneal exudate macrophages purified from mice. We sequenced anti-STAT3 ChIP-seq as well as corresponding control (Input) libraries
Project description:Signal transducer and activator of transcription 3 (STAT3) is altered in several epithelial cancers and represents a potential therapeutic target. Here, STAT3 expression, activity and cellular functions were examined in two main histotypes of esophageal carcinomas. In situ, immunohistochemistry for STAT3 and STAT3-Tyr705 phosphorylation (P-STAT3) in esophageal squamous cell carcinomas (ESCC) and BarrettM-bM-^@M-^Ys adenocarcinomas (BAC) revealed similar STAT3 expression in ESCCs and BACs, but preferentially activated P-STAT3 in ESCCs. In vitro, strong STAT3 activation was seen by EGF-stimulation in OE21 (ESCC) cells, whilst OE33 (BAC) cells showed constitutive weak STAT3 activation. STAT3 knockdown significantly reduced cell proliferation of OE21 and OE33 cells and reduced cell migration in OE33, but not in OE21 cells. Transcriptome analysis identified STAT3-knockdown associated down-regulation of cell cycle processes and the selective down-regulation of cyclins and cyclin dependent kinaes associated genes in both OE21 and OE33 cells. Moreover, the transcriptome response showed changes in cell migration/invasion related genes that correlated with the associated phenotype measurements. This study demonstrates the importance of STAT3 expression and activation in esophageal carcinomas, whereby the extent differs between ESCCs and BACs. STAT3 knockdown significantly reduces cell proliferation in both types of esophageal cancer cells and inhibits migration in BAC cells. Thus, STAT3 may be further exploited as potential novel therapeutic target for esophageal cancers. The effect of STAT3 knock-down in OE33 and OE21 cells was calculated from three biologically independent experiments. 3x10e4 cells were seeded in triplicate in 24 well-plates and were transfected with twice 100nM STAT3 siRNA (pool of 4 STAT3 sequences, siGENOMEM-BM-.SMARTpoolM-BM-., Dharmacon RNAi Technologies, Thermo Fisher Scientific, Lafayette, USA) or SilencerM-BM-. negative siRNA control (Invitrogen/Life Technologies GmbH, Darmstadt, Germany) using 1M-BM-5l DharmaFECT (Dharmacon RNAi Technologies, Thermo Fisher Scientific, Lafayette, USA) transfection reagent for OE33 cells or siPORTTM NeoFXTM (Invitrogen/Life Technologies GmbH, Darmstadt, Germany) transfection reagent for OE21 cells. Differential gene regulation was quantified 72 hours after the first transfection by comparing separately for the OE21 and OE33 cells the STAT3 siRNA replicates and the respective cell lines containing the scrambled siRNA vector.
Project description:STAT3 is determined to play a crucial role in JAK/STAT signaling pathway. The mutations and copy number alteration of STAT3 can cause cancers and other diseases. The 317-567 amino acid domain of STAT3 protein contributes to binding with genomic DNA for gene activation. However, the impact of the mutations within DNA binding domain of STAT3 on the genomic binding pattern is not fully understood. Stat3 was deleted the 400-411 amino acid residue of \\"NNGSLSAEFKHL\\" using CRISPR-CAS9 in human colon cancer cells SW480. The cells were performed STAT3 ChIP-seq to investigate the genome-wide binding pattern of STAT3 between wild type and mutant STAT3 of SW480.
Project description:Dendritic cells (DC) play a vital role in the induction of activation or tolerance of immune response. STAT3 is a master transcriptional regulator of immune response in DCs by positively or negatively regulating DC function, but the mechanisms are unknown. STAT3 is post-translationally modified by acetylation or phosphorylation. While much is understood about transcriptional targets of phosphorylated STAT3, the gene targets and the functional impact of acetylated-STAT3 remain unclear. We aimed to answer the gene targets of acetylated-STAT3 and test the hypothesis that acetylation of STAT3 plays a key role in negative regulation of DCs. We performed genome-wide binding analysis of acetyl-STAT3 by ChIP-Seq coupled with gene expression microarrays. Acetylation of STAT3 induced by SAHA increased its capability to bind to target DNA sites in genome. Theses binding sites were mostly proximal but some were also distal up to over 100 kb from transcription start site. Gene expression array showed 1701 genes up-regulated and 1668 genes down-regulated. Proximal binding of acety-STAT3 showed more effective transcription function than distal binding. In top 500 binding peaks, the frequency of canonical motifs bound by acetyl-STAT3 were significantly higher than that for noncanonical motifs (p<0.00001). Functional analysis revealed that acetyl-STAT3 regulates target genes by upregulating genes that are primarily involved in negative regulation of cytokine production and IL-10 signaling, or downregulating genes that are primarily involved in immune effector process and antigen processing/presentation. Upregulation of IL-10Ra by acetyl-STAT3 contributes to the enhanced sensitivity of IL-10 signaling and negative regulation of DC function. Bone marrow derived dendritic cells were treated with SAHA (500 nm) or diluent for 12 hours. ChIP was performed using antibodies against STAT3, H3K4me3 and matched IgG control. DNA binding profiles were generated by deep sequencing using Illumina HiSeq 2000.
Project description:Signal transducer and activator of transcription 3 (STAT3) is altered in several epithelial cancers and represents a potential therapeutic target. Here, STAT3 expression, activity and cellular functions were examined in two main histotypes of esophageal carcinomas. In situ, immunohistochemistry for STAT3 and STAT3-Tyr705 phosphorylation (P-STAT3) in esophageal squamous cell carcinomas (ESCC) and Barrett’s adenocarcinomas (BAC) revealed similar STAT3 expression in ESCCs and BACs, but preferentially activated P-STAT3 in ESCCs. In vitro, strong STAT3 activation was seen by EGF-stimulation in OE21 (ESCC) cells, whilst OE33 (BAC) cells showed constitutive weak STAT3 activation. STAT3 knockdown significantly reduced cell proliferation of OE21 and OE33 cells and reduced cell migration in OE33, but not in OE21 cells. Transcriptome analysis identified STAT3-knockdown associated down-regulation of cell cycle processes and the selective down-regulation of cyclins and cyclin dependent kinaes associated genes in both OE21 and OE33 cells. Moreover, the transcriptome response showed changes in cell migration/invasion related genes that correlated with the associated phenotype measurements. This study demonstrates the importance of STAT3 expression and activation in esophageal carcinomas, whereby the extent differs between ESCCs and BACs. STAT3 knockdown significantly reduces cell proliferation in both types of esophageal cancer cells and inhibits migration in BAC cells. Thus, STAT3 may be further exploited as potential novel therapeutic target for esophageal cancers.
Project description:Interleukin 2 (IL-2), a cytokine linked to human autoimmune diseases, limits IL-17 production. We show that deletion of Stat3 in T cells abrogates IL-17 production and attenuates autoimmunity associated with IL-2 deficiency. While STAT3 induces IL-17 and RORγt and inhibits Foxp3, IL-2 inhibited IL-17 independently of Foxp3 and RORγt. We found that STAT3 and STAT5 bound to multiple common sites across the Il17 genetic locus. The induction of STAT5 binding by IL-2 was associated with a reduction in STAT3 binding at these sites and the inhibition of associated active epigenetic marks. Titrating the relative activation of STAT3 and STAT5 modulated TH17 cell specification. Thus, the balance rather than the absolute magnitude of these signals determines the propensity of cells to make a key inflammatory cytokine. The genome-wide binding of STAT3 and STAT5 under Th17 conditions was investigated by CHIP-seq.
Project description:In many human cancers the transcription factor STAT3 is constitutively active and contributes to oncogenesis, tumour growth and progression. Recently, gain-of-function mutations of STAT3 have been identified in patients suffering from various haematopoietic malignancies and are postulated to enhance the transcriptional activity of STAT3. We investigated the gene expression and binding profile of the most common STAT3 mutant Y640F compared to wild-type STAT3, describing it's mechanism of action and pinpointing to novel therapeutic intervention sites.
Project description:Pancreatic ductal adenocarcinoma (PDAC) has a characteristically dense stroma comprised predominantly of cancer associated fibroblasts (CAFs). CAFs promote tumor growth, metastasis and treatment resistance. We aimed to investigate the molecular changes and functional consequences associated with chemotherapy treatment of PDAC CAFs. Chemoresistant immortalized CAFs (R-CAFs) were generated by continuous incubation in 100nM gemcitabine. Gene expression differences between treatment naïve CAFs (N-CAFs) and R-CAFs were compared by array analysis. Immortalized human pancreatic CAFs were grown for 30 days in either control media or media containing 100nM gemcitabine. RNA was then isolated and hybidized on U133 Plus 2.0 Affymetrix arrays.
Project description:To understand the difference of protein expression between paired esophageal squamous cell carcinoma (ESCC) and adjacent normal tissues, we collected 10 paired ESCC and normal tissues from surgical resected specimems for high-throughput proteomic experiments. From comparative analysis, the dysregulated signaling pathways in ESCC could be uncovered.