PPT1 is a negative regulator of STING signaling in cancer cells and its inhibition reactivates immune surveillance in cold tumors
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ABSTRACT:
PROVIDER: PRJNA1269077 | ENA |
REPOSITORIES: ENA
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Project description:Immunotherapy modalities have revolutionized cancer treatment for a number of metastatic and treatment-refractory tumor types. Still, many malignancies that are lacking in T cell infiltrates and immunologically “cold” fail to respond to these modalities. One approach to increase tumor immunogenicity has been to induce STING and downstream interferon signaling that is often dysregulated in “cold” tumors. Despite some early success of STING agonists in preclinical cancer models, these approaches have not been successful in the clinic due to poor tumor penetrance and systemic toxicities. Here we performed a genome-wide CRISPR screen to uncover novel therapeutic targets to activate STING expression in human tumors. We identified Palmitoyl Protein Thioesterase1 (PPT1) as a negative regulator of STING highly expressed in “cold” ovarian and prostate tumors. Genetic or pharmacological PPT1 suppression increased STING protein stability and its downstream activation of interferon and inflammatory cytokine signaling to enhance T cell migration. Treatment of preclinical prostate and ovarian cancer models expressing low levels of STING with the small molecule PPT1 inhibitor GNS561 enhanced STING expression and activation, leading to infiltration and activation of cytotoxic T cells that turned these tumors “hot” and reduced tumor growth, fibrosis, and dissemination without toxicity. Further analysis demonstrated that PPT1 is associated with reduced STING expression, CD8+ T cell numbers, overall survival, and immunotherapy outcomes in ovarian and prostate cancer patients. Thus, PPT1 inhibition may be a promising approach to activate STING and potentiate the effects of immunotherapy in “cold” tumors.
2025-09-01 | GSE298396 | GEO
Project description:Lysosomes are essential organelles for cellular homeostasis. Defective lysosomes are associated with many human diseases, such as lysosomal storage disorders (LSD). How the cell detects lysosomal defects and then restores lysosomal function remain incompletely understood. Here, we show that STING mediates a common neuroinflammatory gene signature in three distinct lysosomal storage disorders, Galctwi/twi, Ppt1-/-, and Cln7-/-. Transcriptomic analysis of Galctwi/twi brain tissue revealed that STING also mediates the expression of a broad panel of lysosomal genes that are part of the CLEAR (Coordinated Lysosomal Expression and Regulation) signaling pathway, which is regulated by transcriptional factor EB (TFEB). Immunohistochemical and single-nucleus RNA-seq analysis show that STING regulates lysosomal gene expression in microglia in LSD mice. Mechanistically, we show that STING activation in both human and mouse cells leads to TFEB dephosphorylation, nuclear translocation, and expression of target lysosomal genes. In addition, STING-mediated TFEB activation requires its proton channel function, the V-ATPase-ATG5-ATG8 cascade, and is independent of immune signaling. Functionally, we show that the STING-proton channel-TFEB axis plays a role in facilitating lysosomal repair. Together, our data identify STING-TFEB as a lysosomal quality control and recovery mechanism that responds to both genetic and chemically induced lysosomal dysfunction.
2025-04-23 | GSE283768 | GEO
Project description:Chronic stimulation of innate immune pathways by microbial agents or damaged tissue is known to promote inflammation-driven tumorigenesis by unclarified mechanisms1-3. Here we demonstrate that mutagenic 7,12-dimethylbenz(a)anthracene (DMBA), etoposide or cisplatin induces nuclear DNA leakage into the cytosol to intrinsically activate STING (Stimulator of Interferon Genes) dependent cytokine production. Inflammatory cytokine levels were subsequently augmented in a STING-dependent extrinsic manner by infiltrating phagocytes purging dying cells. Consequently, STING-/- mice, or wild type mice adoptively transferred with STING-/- bone marrow, were almost completely resistant to DMBA-induced skin carcinogenesis compared to their wild type counterparts. Our data emphasizes, for the first time, a role for STING in the induction of cancer, sheds significant insight into the causes of inflammation-driven carcinogenesis, and may provide therapeutic strategies to help prevent malignant disease Total RNA obtained from wild type murine embryonic fibroblasts (WT MEFs), STING deficient MEFs (SKO), Trex1 deficient MEFs (TKO), and both STING and Trex1 deficient MEFs (STKO) treated with DMBA and examined cytokine production by these cells.
2014-05-31 | E-GEOD-57603 | biostudies-arrayexpress
Project description:The MYC oncogene is frequently amplified in triple negative breast cancer (TNBC). Here, we show that MYC suppression induces immune-related hallmark gene set signatures and tumor infiltrating T cells in MYC-hyperactivated TNBCs. Mechanistically, MYC repressed stimulator of interferon genes (STING) expression via direct binding to the STING enhancer region, resulting in downregulation of the T cell chemokines CCL5, CXCL10 and CXCL11. In primary and metastatic TNBC cohorts, tumors with high MYC expression or activity exhibited low STING expression. Using a CRISPR-mediated enhancer perturbation approach, we demonstrated that MYC-driven immune evasion is mediated by STING repression. STING repression induced resistance to PD-L1 blockade in mouse models of TNBC. Finally, a small molecule inhibitor of MYC combined with PD-L1 blockade elicited a durable response in immune-cold TNBC with high MYC levels, suggesting a strategy to restore PD-L1 inhibitor sensitivity in MYC-overexpressing TNBC.
2022-03-01 | GSE196324 | GEO
Project description:The MYC oncogene is frequently amplified in triple negative breast cancer (TNBC). Here, we show that MYC suppression induces immune-related hallmark gene set signatures and tumor infiltrating T cells in MYC-hyperactivated TNBCs. Mechanistically, MYC repressed stimulator of interferon genes (STING) expression via direct binding to the STING enhancer region, resulting in downregulation of the T cell chemokines CCL5, CXCL10 and CXCL11. In primary and metastatic TNBC cohorts, tumors with high MYC expression or activity exhibited low STING expression. Using a CRISPR-mediated enhancer perturbation approach, we demonstrated that MYC-driven immune evasion is mediated by STING repression. STING repression induced resistance to PD-L1 blockade in mouse models of TNBC. Finally, a small molecule inhibitor of MYC combined with PD-L1 blockade elicited a durable response in immune-cold TNBC with high MYC levels, suggesting a strategy to restore PD-L1 inhibitor sensitivity in MYC-overexpressing TNBC.
2022-03-01 | GSE196323 | GEO
Project description:Chronic stimulation of innate immune pathways by microbial agents or damaged tissue is known to promote inflammation-driven tumorigenesis by unclarified mechanisms1-3. Here we demonstrate that mutagenic 7,12-dimethylbenz(a)anthracene (DMBA), etoposide or cisplatin induces nuclear DNA leakage into the cytosol to intrinsically activate STING (Stimulator of Interferon Genes) dependent cytokine production. Inflammatory cytokine levels were subsequently augmented in a STING-dependent extrinsic manner by infiltrating phagocytes purging dying cells. Consequently, STING-/- mice, or wild type mice adoptively transferred with STING-/- bone marrow, were almost completely resistant to DMBA-induced skin carcinogenesis compared to their wild type counterparts. Our data emphasizes, for the first time, a role for STING in the induction of cancer, sheds significant insight into the causes of inflammation-driven carcinogenesis, and may provide therapeutic strategies to help prevent malignant disease Total RNA obtained from DMBA or acetone treated wild type (WT) or STING deficient (SKO) mouse skin or skin tumor was examined for gene expression.
2014-05-31 | E-GEOD-57604 | biostudies-arrayexpress
Project description:The STING signaling pathway plays important roles in many cancers, viral and bacterial infections, and autoimmune diseases. Understanding how STING mediates expression of many proteins in the host and bacterial cells can provide important clues about the biochemical processes, opening the door for the development of new therapies. Using STING KO cells, we were able to identify many differentially expressed proteins between the wild type and STING KO RAW macrophage. We identified proteins that were exclusively detected only in the wild type or only in the STING KO, as well as those that were comply identified but showed different levels of expressions between the two cell lines. This included several proteins that are known as potent biomarkers of various cancers and autoimmune diseases. Our data broaden the knowledge of proteins that are related to STING signaling, and may have identified novel proteins that have therapeutic value. This will require rigorous validation in the future studies. Many protein biomarkers can be regulated by post-translational modifications and protein-protein interactions. While beyond the scope of the current study, we note that methods are available at the Purdue Proteomics Facility for mapping post-translational modifications and protein-protein interactions. We envision this to be an exciting line of enquiry for us in the future.
2019-07-03 | MSV000084058 | MassIVE
Project description:STING gain-of-function (GOF) mutations lead to T cell lymphopenia, in the context of severe combined immunodeficiency (SCID) for STING GOF V154M mice. This T cell lymphopenia, which is of central origin, has been described as type I IFN independent and associated with dysfunctions of the rare mature T cells found in the periphery. To better describe the biological mechanisms of these dysfunctions, we performed a transcriptomic analysis by RNA-seq on sorted splenic CD4+ and CD8+ mature T cells from STING GOF mice. We highlighted an unexpected T cell exhaustion phenotype that could partly explain their dysfunctions. Acquired very early in life, but only once the peripheral environment is reached, the phenotype appeared to depend neither on type I IFNs, nor on the intrinsic activation of STING in T or stromal cells. Mechanistically, the few mature T cells reaching the periphery seem to be rapidly impacted by the lymphopenic environment through increased antigenic and IL-7 stimulations that could lead to their exhaustion. By using STING GOF long term-hematopoietic stem cells (LT-HSC) transplantations with supportive wild-type bone marrow (BM) cells, we prevented the T cell exhaustion of STING GOF T cells in the resulting non lymphopenic context. With the support of lymphopenic RAG1 hypomorphic mice developing the phenotype, our data uncover a lymphopenia-mediated T cell exhaustion mechanism in STING GOF mice, for which a synergistic effect of the mutation is also envisaged.
2024-01-07 | E-MTAB-13658 | biostudies-arrayexpress
Project description:Inflammatory diseases such as Aicardi-Goutieres Syndrome (AGS) and severe systemic lupus erythematosus (SLE) are generally lethal disorders that have been traced to defects in the exonuclease Trex1 (DNAseIII). Mice lacking Trex1 similarly die at an early age through comparable symptoms, including inflammatory myocarditis, through chronic activation of the STING (stimulator of interferon genes) pathway. Here we demonstrate that phagocytes rather than myocytes are predominantly responsible for causing inflammation, an outcome that could be alleviated following adoptive transfer of normal bone marrow into Trex1-/- mice. Trex1-/- macrophages did not exhibit significant augmented ability to produce pro-inflammatory cytokines compared to normal macrophages following exposure to STING-dependent activators, but rather appeared chronically stimulated by genomic DNA. These results shed molecular insight into inflammation and provide concepts for the design of new therapies. Total RNA obtained from wild type (WT), Trex1 deficient (TKO), STING deficient (SKO), or Trex1 and STING double deficient (STKO) mouse Heart
2014-07-09 | E-GEOD-59217 | biostudies-arrayexpress
Project description:Bulk RNAseq of pancreatic stellate cells (PSC) and tumour cells treated with STING agonist DMXAA, STING inhibitor H151 or DMSO control. PSC were cultured alone as mono-cultures or in co-culture with mouse tumour organoids, The PSC and tumour cells were recovered by FACS using fluorecent proteins mKate-2 and tGFP, respectively.
2025-03-19 | E-MTAB-14946 | biostudies-arrayexpress