Project description:Notch signaling is frequently hyperactivated in breast cancer, but how the enhanced signaling contributes to the tumor process is less well understood. In this report, we identify the proinflammatory cytokine interleukin-6 (IL-6) as a novel Notch target in breast tumor cells. Enhanced Notch signaling upregulated IL-6 expression at the transcriptional level, leading to activation of autocrine and paracrine JAK/STAT signaling. IL-6 upregulation was mediated by non-canonical Notch signaling, as it could be effectuated by a cytoplasmically localized Notch intracellular domain and was independent on the DNA-binding protein CSL. Instead, Notch-mediated IL-6 upregulation was controlled by two other factors: IKKβ, a protein in the NF-kB signaling cascade, and p53. Activation of IL-6 by Notch required IKKβ function, but interestingly, did not engage canonical NF-κB signaling, in contrast to IL-6 activation by inflammatory agents such as tumor necrosis factor, which requires canonical NF-κB signaling. With regard to p53 status, IL-6 expression was upregulated by Notch when p53 was mutated or lost, but restoring wildtype 53 into p53-mutated or -deficient cells abrogated the IL-6 upregulation. Furthermore, Notch-induced genome-wide transcriptomes from p53 wildtype and -mutated breast tumor cell lines differed extensively, and in a subset of genes upregulated by Notch in a p53-mutant cell line, upregulation was reduced by wildtype p53. In conclusion, we identify IL-6 as a novel non-canonical Notch target gene, and reveal roles for p53 and IKKβ in non-canonical Notch signaling in breast cancer and in the generation of cell context-dependent diversity in the Notch signaling output.
Project description:Notch signaling is frequently hyperactivated in breast cancer, but how the enhanced signaling contributes to the tumor process is less well understood. In this report, we identify the proinflammatory cytokine interleukin-6 (IL-6) as a novel Notch target in breast tumor cells. Enhanced Notch signaling upregulated IL-6 expression at the transcriptional level, leading to activation of autocrine and paracrine JAK/STAT signaling. IL-6 upregulation was mediated by non-canonical Notch signaling, as it could be effectuated by a cytoplasmically localized Notch intracellular domain and was independent on the DNA-binding protein CSL. Instead, Notch-mediated IL-6 upregulation was controlled by two other factors: IKKβ, a protein in the NF-kB signaling cascade, and p53. Activation of IL-6 by Notch required IKKβ function, but interestingly, did not engage canonical NF-κB signaling, in contrast to IL-6 activation by inflammatory agents such as tumor necrosis factor, which requires canonical NF-κB signaling. With regard to p53 status, IL-6 expression was upregulated by Notch when p53 was mutated or lost, but restoring wildtype 53 into p53-mutated or -deficient cells abrogated the IL-6 upregulation. Furthermore, Notch-induced genome-wide transcriptomes from p53 wildtype and -mutated breast tumor cell lines differed extensively, and in a subset of genes upregulated by Notch in a p53-mutant cell line, upregulation was reduced by wildtype p53. In conclusion, we identify IL-6 as a novel non-canonical Notch target gene, and reveal roles for p53 and IKKβ in non-canonical Notch signaling in breast cancer and in the generation of cell context-dependent diversity in the Notch signaling output. 30 microarray samples consisting of MCF7 (ER+, wild-type p53, luminal type B breast cancer) and MDA-MB-231 (ER-, mutated p53, basal breast cancer) cells cultured on immobilized 1 μg/ml JAGGED1-Fc or 1 μg/ml DLL4-Fc or 1 μg/ml Fc control with or without 5 μM DAPT for 6 hours in 3 biological replicates.
Project description:Although the JAK/STAT pathway regulates numerous processes in vertebrates and invertebrates through modulating transcription, its functionally-relevant transcriptional targets remain largely unknown. With one jak and one stat (stat92E), Drosophila provides a powerful system for finding new JAK/STAT target genes. Genome-wide expression profiling on eye discs in which Stat92E is hyperactivated, revealed 584 differentially-regulated genes, including known targets domeless, socs36E and wingless. Other differentially-regulated genes (chinmo, lama, Mo25, Imp-L2, Serrate, Delta) were validated and may represent new Stat92E targets. Genetic experiments revealed that Stat92E cell-autonomously represses Serrate, which encodes a Notch ligand. Loss of Stat92E led to de-repression of Serrate in the dorsal eye, resulting in ectopic Notch signaling and aberrant eye growth there. Thus, our micro-array documents a new Stat92E target gene and a previously-unidentified inhibitory action of Stat92E on Notch signaling. These data suggest that this study will be a useful resource for the identification of additional Stat92E targets. Identification of the JAK/STAT pathway target genes in the Drosophila eye disc Keywords: Genotype comparison Gene expression profiles from five biological replicates of eye discs with yw (control) and GMR-upd (overexpressing JAK/STAT ligand unpaired) were compared using genome wide mRNA expression profiling by Affymetrix genechip arrays (Drosophila 2.0) and key targets were validated by clonal analysis, in situ hybridization, immunohistochemical staining and quantitative real-time PCR.
Project description:High-resolution mass spectrometry analysis of Interleukin 2 (IL-2) and Janus kinase (JAK) controlled protein phosphorylations in cytotoxic T lymphocytes (CTL) revealed JAKs coupled IL-2 receptors to diverse and complex serine/threonine kinase-substrate networks. These involved intricate, co-ordinated phosphorylation of transcription factors, chromatin regulators within the nuclear environment, cytosolic mRNA translational machinery, regulators of GTPases, vesicle trafficking proteins and the actin and microtubule cytoskeleton. We also identified an IL-2-JAK independent SRC family Tyr kinase controlled signaling network that regulates ~10% of the CTL phosphoproteome. One key signaling pathway in CTL is mediated by phosphatidylinositol (3,4,5)-trisphosphate (PIP3) and the serine/threonine kinase AKT. Strikingly, SRC family kinase dependent but JAK independent signaling controlled PIP3 levels and AKT activity in CTL. IL-2-JAK controlled signaling pathways thus coordinate with IL-2 independent networks of protein phosphorylation to program CTL fate.
Project description:Although the JAK/STAT pathway regulates numerous processes in vertebrates and invertebrates through modulating transcription, its functionally-relevant transcriptional targets remain largely unknown. With one jak and one stat (stat92E), Drosophila provides a powerful system for finding new JAK/STAT target genes. Genome-wide expression profiling on eye discs in which Stat92E is hyperactivated, revealed 584 differentially-regulated genes, including known targets domeless, socs36E and wingless. Other differentially-regulated genes (chinmo, lama, Mo25, Imp-L2, Serrate, Delta) were validated and may represent new Stat92E targets. Genetic experiments revealed that Stat92E cell-autonomously represses Serrate, which encodes a Notch ligand. Loss of Stat92E led to de-repression of Serrate in the dorsal eye, resulting in ectopic Notch signaling and aberrant eye growth there. Thus, our micro-array documents a new Stat92E target gene and a previously-unidentified inhibitory action of Stat92E on Notch signaling. These data suggest that this study will be a useful resource for the identification of additional Stat92E targets. Identification of the JAK/STAT pathway target genes in the Drosophila eye disc Keywords: Genotype comparison
Project description:D122p53 mice (a model of D133p53 isoform) are tumour prone, have extensive inflammation and elevated serum IL-6. To investigate the role of IL-6 we crossed ∆122p53 mice with IL-6 deficient mice. Here we show that loss of IL-6 reduced JAK-STAT signalling, tumour incidence, and metastasis. We also show that D122p53 activates RhoA-ROCK signalling leading to tumour cell invasion which is IL-6 dependent and can be reduced by inhibition of JAK-STAT and RhoA-ROCK pathways. Similarly, we show that Δ133p53 activates the these pathways, resulting in invasive and migratory phenotypes, in colorectal cancer cells. Gene expression analysis of colorectal tumours showed enrichment of GPCR signalling associated with D133TP53 mRNA. Patients with elevated D133TP53 mRNA levels had a shorter disease free survival. Our results suggest that D133p53 promotes tumour invasion by activation of the JAK-STAT and RhoA-ROCK pathways and that patients whose tumours have high D133p53 may benefit from therapies targeting these pathways. In this dataset, we included the gene expression data from 35 colorectal cancers. These data were used to identify a list of enriched genesets associated with D133TP53 mRNA expression in colorectal tumours
Project description:JAK/STAT pathway plays important roles in controlling Drosophila intestinal homeostasis and regulating the ISC proliferation and differentiation. However,the downstream targets of its transcription factor-STAT92E remain largely unknown.To further identify the regualtory mechanisms of the JAK/STAT pathway in controlling intestinal homeostasis,we performed the ChIP-Seq assay with mouse raised STAT92E antibody using JAK/STAT signaling highly activated adult intestines.Through the ChIP assay, we have identified over 1000 significant peaks (p<0.01) around the putative targets.The well-characterized JAK/STAT downstream targets including Domeless,Socs36E,STAT92E and chinmo were identified in our ChIP assay,indicating that our experiment is workable to identify novel JAK/STAT downstream targets in adult intestines.This work will provide insights into our understanding of regulatory mechanisms of JAK/STAT signaling during Drosophila intestinal development. Identify the ChIP peaks of STAT92E antibody using JAK/STAT signaling highly actived Drosophila adult intestines, compared with input libaray as the control
Project description:Organ transplant recipients (OTRs) on Cyclosporine A (CSA) are prone to catastrophic cutaneous squamous cell carcinoma (SCC). Allograft-sparing, cancer-targeting systemic treatments are unavailable. We have shown increased risk for catastrophic SCC in OTRs via CSA-mediated induction of Interleukin-22 (IL-22). Herein, we found CSA drives SCC proliferation and tumor growth through IL-22 and JAK/STAT pathway induction. We in turn inhibited SCC growth with an FDA-approved JAK 1/2 inhibitor, Ruxolitinib. In human SCC cells, greatest proliferative response to IL-22 and CSA treatment occurred in non-metastasizing lines. IL-22 treatment upregulated JAK1 and STAT1/3 in A431 SCC cells. JAK/STAT pathway genes were highly expressed in tumors from a cohort of CSA-exposed OTRs, and in SCC with high risk for metastasis. Compared to immunocompetent SCC, genes associated with innate immunity, response to DNA damage and p53 regulation were differentially expressed in SCC from OTRs. In nude mice engrafted with human A431 cells, IL-22 and CSA treatment increased tumor growth and upregulated IL-22 receptor, JAK1 and STAT 1/3 expression. Ruxolitinib treatment significantly reduced tumor volume and reversed the accelerated tumor growth. CSA and IL-22 exacerbate aggressive behavior in SCC. Targeting the IL-22 axis via selective JAK/STAT inhibition may reduce the progression of aggressive SCC in OTRs, without compromising immunosuppression. In this study, microarray data was used to compare normal skin to immunocompetent SCC, to transplant associated SCC (TSCC)
Project description:Disease-initiating mutations in the transcription factor RUNX1 occur as germline and somatic events that cause leukemias with particularly poor prognosis. However, the role of RUNX1 in leukemogenesis is not fully understood and effective therapies for RUNX1-mutant leukemias remain elusive. Here, we use primary patient samples and a RUNX1 knockout model in primary human hematopoietic cells to investigate how RUNX1 loss contributes to leukemic progression and to identify targetable vulnerabilities. Surprisingly, we found that RUNX1 loss decreased proliferative capacity and stem cell function. However, RUNX1-deficient cells selectively upregulated the interleukin-3 (IL-3) receptor. Exposure to IL-3, but not other JAK/STAT cytokines, rescued RUNX1 KO proliferative and competitive defects. Further, we demonstrated that RUNX1 loss repressed JAK/STAT signaling and rendered RUNX1-deficient cells sensitive to JAK inhibitors. Our study identifies a dependency of RUNX1-mutant leukemias on IL-3/JAK/STAT signaling, which may enable these aggressive blood cancers to be targeted with existing agents.
Project description:Disease-initiating mutations in the transcription factor RUNX1 occur as germline and somatic events that cause leukemias with particularly poor prognosis. However, the role of RUNX1 in leukemogenesis is not fully understood and effective therapies for RUNX1-mutant leukemias remain elusive. Here, we use primary patient samples and a RUNX1 knockout model in primary human hematopoietic cells to investigate how RUNX1 loss contributes to leukemic progression and to identify targetable vulnerabilities. Surprisingly, we found that RUNX1 loss decreased proliferative capacity and stem cell function. However, RUNX1-deficient cells selectively upregulated the interleukin-3 (IL-3) receptor. Exposure to IL-3, but not other JAK/STAT cytokines, rescued RUNX1 KO proliferative and competitive defects. Further, we demonstrated that RUNX1 loss repressed JAK/STAT signaling and rendered RUNX1-deficient cells sensitive to JAK inhibitors. Our study identifies a dependency of RUNX1-mutant leukemias on IL-3/JAK/STAT signaling, which may enable these aggressive blood cancers to be targeted with existing agents.