Similar Datasets
Project description:Glioblastoma (GBM) is an incurable cancer despite aggressive treatment paradigms. Current immunotherapies, such as CTLA-4 and/or PD-1 blockade, have yet to demonstrate benefits for GBM. A key barrier is the immunologically “cold” nature of GBM defined by insufficient tumor antigen presentation and lack of T cells infiltration. We previously demonstrated that pharmacologic inhibition of Protein Phosphatase-2A (PP2A), using a small molecule inhibitor, synergized with PD1 blockade in multiple preclinical tumor models including GBM. However, PP2A is ubiquitously expressed in many cell types and regulates many cellular pathways. The cell type or molecular mechanism responsible for PP2A-modulated tumor immunity is poorly understood. Here, we demonstrate that genetic ablation of PP2A in glioma cells sufficiently promotes tumor immunogenicity by enhancing 1) dsDNA production and thereby cGAS-Type I interferon (IFN) signaling, 2) MHC-I expression and 3) tumor mutational burden. PP2A deficient glioma enhances DC activation and cross presentation to promote clonal expansion of tumor antigen specific CD8 cells. PP2A deficiency also markedly sensitize tumors to immune checkpoint blockade and radiotherapy. Single cell analysis of murine glioma demonstrates that PP2A deficient tumors have 1) increased infiltration of CD8+ T cell, NK cell and cDC1 cells, 2) reduced infiltration of immunosuppressive tumor associated macrophages, 3) promotion of IFN signaling in both myeloid and tumor cells, and 4) reduced glioma-associated gene signature that predicts poor prognosis in glioma patients. This is the first study to establish a role for PP2A in regulating dsDNA-cGAS-STING signaling and collectively, our results suggest that PP2A is a promising novel target to enhance anti-tumor immunity for glioma.
2023-05-17 | GSE213308 | GEO
Project description:Glioblastoma (GBM) is an incurable cancer despite aggressive treatment paradigms. Current immunotherapies, such as CTLA-4 and/or PD-1 blockade, have yet to demonstrate benefits for GBM. A key barrier is the immunologically “cold” nature of GBM defined by insufficient tumor antigen presentation and lack of T cells infiltration. We previously demonstrated that pharmacologic inhibition of Protein Phosphatase-2A (PP2A), using a small molecule inhibitor, synergized with PD1 blockade in multiple preclinical tumor models including GBM. However, PP2A is ubiquitously expressed in many cell types and regulates many cellular pathways. The cell type or molecular mechanism responsible for PP2A-modulated tumor immunity is poorly understood. Here, we demonstrate that genetic ablation of PP2A in glioma cells sufficiently promotes tumor immunogenicity by enhancing 1) dsDNA production and thereby cGAS-Type I interferon (IFN) signaling, 2) MHC-I expression and 3) tumor mutational burden. PP2A deficient glioma enhances DC activation and cross presentation to promote clonal expansion of tumor antigen specific CD8 cells. PP2A deficiency also markedly sensitize tumors to immune checkpoint blockade and radiotherapy. Single cell analysis of murine glioma demonstrates that PP2A deficient tumors have 1) increased infiltration of CD8+ T cell, NK cell and cDC1 cells, 2) reduced infiltration of immunosuppressive tumor associated macrophages, 3) promotion of IFN signaling in both myeloid and tumor cells, and 4) reduced glioma-associated gene signature that predicts poor prognosis in glioma patients. This is the first study to establish a role for PP2A in regulating dsDNA-cGAS-STING signaling and collectively, our results suggest that PP2A is a promising novel target to enhance anti-tumor immunity for glioma.
2023-05-17 | GSE213307 | GEO
Project description:PP2Ac Deficiency Enhances Tumor Immunogenicity by Activating STING-Type I Interferon Signaling in Glioblastoma
| PRJNA880418 | ENA
Project description:PP2Ac Deficiency Enhances Tumor Immunogenicity by Activating STING-Type I Interferon Signaling in Glioblastoma [scRNA]
| PRJNA880422 | ENA
Project description:PP2Ac Deficiency Enhances Tumor Immunogenicity by Activating STING-Type I Interferon Signaling in Glioblastoma [RNA]
| PRJNA880423 | ENA
Project description:This SuperSeries is composed of the SubSeries listed below.
2023-02-09 | GSE199271 | GEO
Project description:STING-Type I interferon (IFN) signaling in myeloid cells plays a critical role in effective antitumor immune responses, but STING agonist as monotherapy has shown limited efficacy in clinical trials. The mechanisms that downregulate STING signaling are not fully understood. Here, we report that Protein phosphatase 2A (PP2A) with its specific B regulatory subunit STRN4 negatively regulated STING-Type I IFN in macrophages. Mice with macrophages PP2A deficiency exhibited reduced tumor progression. The tumor microenvironment showed decreased immunosuppressive and increased IFN-activated macrophages and CD8+ T cells. Mechanistically, we demonstrated that hippo kinase MST1/2 was required for STING activation. STING agonist induced dissociation of PP2A from MST1/2 in normal macrophages, but not in tumor conditioned macrophages. Furthermore, our data showed that STRN4 mediated PP2A binding to and dephosphorylation of hippo kinase MST1/2, resulting in stabilization of YAP/TAZ to antagonize STING activation. In human GBM patients, YAP/TAZ was highly expressed in tumor-associated macrophages but not in non-tumor macrophages. We also demonstrated that PP2A/STRN4 deficiency in macrophages reduced YAP/TAZ expression and sensitized tumor conditioned macrophages to STING stimulation. In summary, we demonstrated that PP2A/STRN4-YAP/TAZ is a previously unappreciated mechanism that mediate immunosuppression in tumor-associated macrophages and targeting PP2A/STRN4-YAP/TAZ axis can sensitize tumors to immunotherapy.
2023-02-09 | GSE199251 | GEO
Project description:STING-Type I interferon (IFN) signaling in myeloid cells plays a critical role in effective antitumor immune responses, but STING agonist as monotherapy has shown limited efficacy in clinical trials. The mechanisms that downregulate STING signaling are not fully understood. Here, we report that Protein phosphatase 2A (PP2A) with its specific B regulatory subunit STRN4 negatively regulated STING-Type I IFN in macrophages. Mice with macrophages PP2A deficiency exhibited reduced tumor progression. The tumor microenvironment showed decreased immunosuppressive and increased IFN-activated macrophages and CD8+ T cells. Mechanistically, we demonstrated that hippo kinase MST1/2 was required for STING activation. STING agonist induced dissociation of PP2A from MST1/2 in normal macrophages, but not in tumor conditioned macrophages. Furthermore, our data showed that STRN4 mediated PP2A binding to and dephosphorylation of hippo kinase MST1/2, resulting in stabilization of YAP/TAZ to antagonize STING activation. In human GBM patients, YAP/TAZ was highly expressed in tumor-associated macrophages but not in non-tumor macrophages. We also demonstrated that PP2A/STRN4 deficiency in macrophages reduced YAP/TAZ expression and sensitized tumor conditioned macrophages to STING stimulation. In summary, we demonstrated that PP2A/STRN4-YAP/TAZ is a previously unappreciated mechanism that mediate immunosuppression in tumor-associated macrophages and targeting PP2A/STRN4-YAP/TAZ axis can sensitize tumors to immunotherapy.
2023-02-09 | GSE199247 | GEO
Project description:An immunosuppressive tumor microenvironment promotes tumor growth and is one of the main factors limiting the response to cancer immunotherapy. We have previously reported that inhibition of vacuolar protein sorting 34 (VPS34), a crucial lipid kinase in the autophagy/endosomal trafficking pathway, decreases tumor growth in several cancer models, increases infiltration of immune cells and sensitizes tumors to anti-programmed cell death protein 1/programmed cell death 1 ligand 1 therapy by upregulation of C-C motif chemokine 5 (CCL5) and C-X-C motif chemokine 10 (CXCL10) chemokines. The purpose of this study was to investigate the signaling mechanism leading to the VPS34-dependent chemokine increase. NanoString gene expression analysis was applied to tumors from mice treated with the VPS34 inhibitor SB02024 to identify key pathways involved in the anti-tumor response. We showed that VPS34 inhibitors increased the secretion of T-cell-recruitment chemokines in a cyclic GMP-AMP synthase (cGAS)/stimulator of interferon genes protein (STING)-dependent manner in cancer cells. Both pharmacological and small interfering RNA (siRNA)-mediated VPS34 inhibition increased cGAS/STING-mediated expression and secretion of CCL5 and CXCL10. The combination of VPS34 inhibitor and STING agonist further induced cytokine release in both human and murine cancer cells as well as monocytic or dendritic innate immune cells. Finally, the VPS34 inhibitor SB02024 sensitized B16-F10 tumor-bearing mice to STING agonist treatment and significantly improved mice survival. These results show that VPS34 inhibition augments the cGAS/STING pathway, leading to greater tumor control through immune-mediated mechanisms. We propose that pharmacological VPS34 inhibition may synergize with emerging therapies targeting the cGAS/STING pathway.
| S-EPMC11306511 | biostudies-literature
Project description:Chronic activation of inflammatory pathways and suppressed interferon are hallmarks of immunosuppressive tumors. Previous studies have shown that CD11b integrin agonists could enhance anti-tumor immunity through myeloid reprograming, but the underlying mechanisms remain unclear. Herein we find that CD11b agonists alter tumor-associated macrophage (TAM) phenotypes by repressing NF-κB signaling and activating interferon gene expression simultaneously. Repression of NF-κB signaling involves degradation of p65 protein and is context independent. In contrast, CD11b agonism induces STING/STAT1 pathway-mediated interferon gene expression through FAK-mediated mitochondrial dysfunction, with the magnitude of induction dependent on the tumor microenvironment and amplified by cytotoxic therapies. Using tissues from phase I clinical studies, we demonstrate that GB1275 treatment activates STING and STAT1 signaling in TAMs in human tumors. These findings suggest potential mechanism-based therapeutic strategies for CD11b agonists and identify patient populations more likely to benefit.
2023-03-21 | GSE220959 | GEO