Project description:We report the transcriptional profiles obtained by next-generation sequencing (NGS) of FACS-purified cells from the dpp-domain of wing imaginal discs from mid-third instar Drosophila melanogaster larvae. The goals of this study are to compare NGS-derived transcriptome profiling (RNA-seq) of dpp-domain cells that have elevated JAK/STAT signaling or elevated Myc expression compared to control cells.
Project description:Tumor-associated macrophages contribute to tumor progression and therapeutic resistance in breast cancer. Within the tumor microenvironment, tumor-derived factors activate pathways that modulate macrophage function. Using in vitro and in vivo models, we find that tumor-derived factors induce activation of the Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) pathway in macrophages. We also demonstrate that loss of STAT3 in myeloid cells leads to enhanced mammary tumorigenesis. Further studies show that macrophages contribute to resistance of mammary tumors to the JAK/STAT inhibitor ruxolitinib in vivo and that ruxolitinib-treated macrophages produce soluble factors that promote resistance of tumor cells to JAK inhibition in vitro. Finally, we demonstrate that STAT3 deletion and JAK/STAT inhibition in macrophages increases expression of the pro-tumorigenic factor cyclooxygenase-2 (COX-2) and that COX-2 inhibition enhances responsiveness of tumors to ruxolitinib. These findings define a novel mechanism through which macrophages promote therapeutic resistance and highlight the importance of understanding the impact of targeted therapies on the tumor microenvironment.
Project description:Immune cells need to sustain a state of constant alertness over a lifetime. Yet, little is known about the regulatory processes that control the fluent and fragile balance that is called homeostasis. Here we demonstrate that JAK-STAT signaling, beyond its role in immune responses, is a major regulator of immune cell homeostasis. We investigated JAK-STAT-mediated transcription and chromatin accessibility across 12 mouse models, including knockouts of all STAT transcription factors and of the TYK2 kinase. Baseline JAK-STAT signaling was detected in CD8+ T cells and macrophages of unperturbed mice – but abrogated in the knockouts and in unstimulated immune cells deprived of their normal tissue context. We observed diverse transcription-regulatory programs, including gene regulation by STAT2 and IRF9 independent of STAT1. In summary, our large-scale dataset and integrative analysis of JAK-STAT mutant and wildtype mice uncovered a crucial role of JAK-STAT signaling in unstimulated immune cells, where it contributes to a poised epigenetic and transcription-regulatory state and helps prepare these cells for rapid response to immune stimuli.
Project description:Here we investigated the effects of JAK/STAT pharmacological inhibition on cHL cell models using ruxolitinib, a JAK 1/2 inhibitor. We use five classical Hodgkin lymphoma cell lines: L428, L1236, L540, KMH2, L591
Project description:Immune cells need to sustain a state of constant alertness over a lifetime. Yet, little is known about the regulatory processes that control the fluent and fragile balance that is called homeostasis. Here we demonstrate that JAK-STAT signaling, beyond its role in immune responses, is a major regulator of immune cell homeostasis. We investigated JAK-STAT-mediated transcription and chromatin accessibility across 12 mouse models, including knockouts of all STAT transcription factors and of the TYK2 kinase. Baseline JAK-STAT signaling was detected in CD8+ T cells and macrophages of unperturbed mice – but abrogated in the knockouts and in unstimulated immune cells deprived of their normal tissue context. We observed diverse transcription-regulatory programs, including gene regulation by STAT2 and IRF9 independent of STAT1. In summary, our large-scale dataset and integrative analysis of JAK-STAT mutant and wildtype mice uncovered a crucial role of JAK-STAT signaling in unstimulated immune cells, where it contributes to a poised epigenetic and transcription-regulatory state and helps prepare these cells for rapid response to immune stimuli.
Project description:Immune cells need to sustain a state of constant alertness over a lifetime. Yet, little is known about the regulatory processes that control the fluent and fragile balance that is called homeostasis. Here we demonstrate that JAK-STAT signaling, beyond its role in immune responses, is a major regulator of immune cell homeostasis. We investigated JAK-STAT-mediated transcription and chromatin accessibility across 12 mouse models, including knockouts of all STAT transcription factors and of the TYK2 kinase. Baseline JAK-STAT signaling was detected in CD8+ T cells and macrophages of unperturbed mice – but abrogated in the knockouts and in unstimulated immune cells deprived of their normal tissue context. We observed diverse transcription-regulatory programs, including gene regulation by STAT2 and IRF9 independent of STAT1. In summary, our large-scale dataset and integrative analysis of JAK-STAT mutant and wildtype mice uncovered a crucial role of JAK-STAT signaling in unstimulated immune cells, where it contributes to a poised epigenetic and transcription-regulatory state and helps prepare these cells for rapid response to immune stimuli.
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.