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Project description:While T cell immunotherapies have demonstrated effectiveness in a subset of patients with diffuse large B cell lymphoma (DLBCL) and follicular lymphoma (FL), they are currently administered without guidance regarding whether the underlying biology or immunology is conducive to a durable response. Moreover, mechanisms explaining CAR-T resistance in B cell lymphomas remain largely unknown, and suitable systems to study lymphomas are currently unavailable, making it infeasible. To address these unmet needs, we developed syngeneic animal models reflecting the genetics, epigenetics, and immunology of human FL and DLBCL. We show that treatment of these models with EZH2 inhibitors reprogrammed them to re-express T cell engagement genes and rendered them highly immunogenic. Notably, EZH2 inhibitors did not exhibit deleterious effects on T cells. Instead, they promoted a memory CAR CD8 phenotype and reduced exhaustion, resulting in a superior elimination of lymphoma B cells and decreased tumor burden. Intravital 2-photon imaging of transformed FL bearing mice showed that EZH2 inhibition increased the recruitment of CAR-T into the tumor microenvironment and enhanced the quality of interactions with lymphoma cells, leading to increased killing. Therefore, inhibition of EZH2 enhances CAR-T cell activity through direct effects on CAR-T cells, in addition to rendering lymphoma B cells immunogenic. This offers an innovative approach for enhancing the prognosis of patients with refractory B cell lymphomas, and is currently under evaluation in a clinical trial (NCT05934838)
2025-01-10 | GSE261745 | GEO
Project description:While T cell immunotherapies have demonstrated effectiveness in a subset of patients with diffuse large B cell lymphoma (DLBCL) and follicular lymphoma (FL), they are currently administered without guidance regarding whether the underlying biology or immunology is conducive to a durable response. Moreover, mechanisms explaining CAR-T resistance in B cell lymphomas remain largely unknown, and suitable systems to study lymphomas are currently unavailable, making it infeasible. To address these unmet needs, we developed syngeneic animal models reflecting the genetics, epigenetics, and immunology of human FL and DLBCL. We show that treatment of these models with EZH2 inhibitors reprogrammed them to re-express T cell engagement genes and rendered them highly immunogenic. Notably, EZH2 inhibitors did not exhibit deleterious effects on T cells. Instead, they promoted a memory CAR CD8 phenotype and reduced exhaustion, resulting in a superior elimination of lymphoma B cells and decreased tumor burden. Intravital 2-photon imaging of transformed FL bearing mice showed that EZH2 inhibition increased the recruitment of CAR-T into the tumor microenvironment and enhanced the quality of interactions with lymphoma cells, leading to increased killing. Therefore, inhibition of EZH2 enhances CAR-T cell activity through direct effects on CAR-T cells, in addition to rendering lymphoma B cells immunogenic. This offers an innovative approach for enhancing the prognosis of patients with refractory B cell lymphomas, and is currently under evaluation in a clinical trial (NCT05934838)
2025-01-10 | GSE255548 | GEO
Project description:While T cell immunotherapies have demonstrated effectiveness in a subset of patients with diffuse large B cell lymphoma (DLBCL) and follicular lymphoma (FL), they are currently administered without guidance regarding whether the underlying biology or immunology is conducive to a durable response. Moreover, mechanisms explaining CAR-T resistance in B cell lymphomas remain largely unknown, and suitable systems to study lymphomas are currently unavailable, making it infeasible. To address these unmet needs, we developed syngeneic animal models reflecting the genetics, epigenetics, and immunology of human FL and DLBCL. We show that treatment of these models with EZH2 inhibitors reprogrammed them to re-express T cell engagement genes and rendered them highly immunogenic. Notably, EZH2 inhibitors did not exhibit deleterious effects on T cells. Instead, they promoted a memory CAR CD8 phenotype and reduced exhaustion, resulting in a superior elimination of lymphoma B cells and decreased tumor burden. Intravital 2-photon imaging of transformed FL bearing mice showed that EZH2 inhibition increased the recruitment of CAR-T into the tumor microenvironment and enhanced the quality of interactions with lymphoma cells, leading to increased killing. Therefore, inhibition of EZH2 enhances CAR-T cell activity through direct effects on CAR-T cells, in addition to rendering lymphoma B cells immunogenic. This offers an innovative approach for enhancing the prognosis of patients with refractory B cell lymphomas, and is currently under evaluation in a clinical trial (NCT05934838)
2025-01-10 | GSE278481 | GEO
Project description:EZH2 INHIBITION ENHANCES T CELL IMMUNOTHERAPIES BY INDUCING LYMPHOMA IMMUNOGENICITY AND IMPROVING T CELL FUNCTION
| PRJNA1088533 | ENA
Project description:EZH2 INHIBITION ENHANCES T CELL IMMUNOTHERAPIES BY INDUCING LYMPHOMA IMMUNOGENICITY AND IMPROVING T CELL FUNCTION (WGS)
| PRJNA1088535 | ENA
Project description:EZH2 INHIBITION ENHANCES T CELL IMMUNOTHERAPIES BY INDUCING LYMPHOMA IMMUNOGENICITY AND IMPROVING T CELL FUNCTION (CUT&RUN)
| PRJNA1167338 | ENA
Project description:EZH2 INHIBITION ENHANCES T CELL IMMUNOTHERAPIES BY INDUCING LYMPHOMA IMMUNOGENICITY AND IMPROVING T CELL FUNCTION (RNA-Seq)
| PRJNA1075425 | ENA
Project description:Two important factors that contribute to resistance to immune checkpoint inhibitors (ICI) are an immune-suppressive microenvironment and limited antigen presentation by tumor cells. In this study, we examine whether inhibition of the methyltransferase enhancer of zeste 2 (EZH2) can increase ICI response in lung squamous cell carcinomas (LSCC). Our in vitro experiments using two-dimensional human cancer cell lines as well as three-dimensional murine and patient-derived organoids treated with two inhibitors of the EZH2 plus IFNγ showed that EZH2 inhibition leads to expression of both MHC class I and II (MHCI/II) expression at both the mRNA and protein levels. Chromatin immunoprecipitation sequencing confirmed loss of EZH2-mediated histone marks and gain of activating histone marks at key loci. Furthermore, we demonstrate strong tumor control in models of both autochthonous and syngeneic LSCC treated with anti-PD1 immunotherapy with EZH2 inhibition. Single-cell RNA sequencing and immune cell profiling demonstrated phenotypic changes toward more tumor suppressive phenotypes in EZH2 inhibitor-treated tumors. These results indicate that EZH2 inhibitors could increase ICI responses in patients undergoing treatment for LSCC.SignificanceThe data described here show that inhibition of the epigenetic enzyme EZH2 allows derepression of multiple immunogenicity factors in LSCC, and that EZH2 inhibition alters myeloid cells in vivo. These data support clinical translation of this combination therapy for treatment of this deadly tumor type.
| S-EPMC10863487 | biostudies-literature
Project description:Two important factors that contribute to resistance to immune checkpoint inhibitors (ICIs) are an immune-suppressive microenvironment and limited antigen presentation by tumor cells. In this study, we examine if inhibition of the methyltransferase EZH2 can increase ICI response in lung squamous cell carcinomas (LSCCs). Our in vitro experiments using 2D human cancer cell lines as well as 3D murine and patient derived organoids treated with two inhibitors of the EZH2 plus interferon-γ (IFNγ) showed that EZH2 inhibition leads to expression of both major histocompatibility complex class I and II (MHCI/II) expression at both the mRNA and protein levels. ChIP-sequencing confirmed loss of EZH2-mediated histone marks and gain of activating histone marks at key loci. Further, we demonstrate strong tumor control in models of both autochthonous and syngeneic LSCC treated with anti-PD1 immunotherapy with EZH2 inhibition. Single-cell RNA sequencing and immune cell profiling demonstrated phenotypic changes towards more tumor suppressive phenotypes in EZH2 inhibitor treated tumors. These results indicate that this therapeutic modality could increase ICI responses in patients undergoing treatment for LSCC.
| S-EPMC10274685 | biostudies-literature
Project description:Gain-of-function mutations in the catalytic site of EZH2 (Enhancer of Zeste Homologue 2), is observed in about 22% of diffuse large B-cell lymphoma (DLBCL) cases. Here we show that selective inhibition of histone deacetylase 1,2 (HDAC1,2) activity using a small molecule inhibitor causes cytotoxic or cytostatic effects in EZH2 gain-of-function mutant (EZH2GOF) DLBCL cells. Our results show that blocking the activity of HDAC1,2 increases global H3K27ac without causing a concomitant global decrease in H3K27me3 levels. Our data shows that inhibition of HDAC1,2 is sufficient to decrease H3K27me3 present at DSBs, decrease DSB repair and activate the DNA damage response in these cells. In addition to increased H3K27me3, we found that the EZH2GOF DLBCL cells overexpress another chemotherapy resistance factor - B-lymphoma and BAL-associated protein (BBAP). BBAP monoubiquitinates histone H4K91, a residue that is also subjected to acetylation. Our results show that selective inhibition of HDAC1,2 increases H4K91ac, decreases BBAP-mediated H4K91 monoubiquitination, impairs BBAP-dependent DSB repair and sensitizes the refractory EZH2GOF DLBCL cells to treatment with doxorubicin, a chemotherapy agent. Hence, selective HDAC1,2 inhibition provides a novel DNA repair mechanism-based therapeutic approach as it can overcome both EZH2- and BBAP-mediated DSB repair in the EZH2GOF DLBCL cells.
| S-EPMC4467121 | biostudies-literature