C-Myb upregulation stimulates antitumor immunity in a murine colorectal cancer model
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PROVIDER: PRJNA974019 | ENA |
REPOSITORIES: ENA
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Project description:While the transcription factor c-Myb is overexpressed in different types of solid tumors, including colorectal cancer, its exact role in tumorigenesis is unclear. In this study, we show that tumor-intrinsic c-Myb expression in mouse models of colon cancer and melanoma suppresses tumor growth. While no difference in proliferation, apoptosis, and angiogenesis of tumors were evident, we observed changes in intratumoral immune cell infiltrates. MC38 tumors with upregulated c-Myb expression showed increased counts of CD103+ dendritic cells and eosinophils, but decreased tumor-associated macrophages (TAMs). Concomitantly, an increase in cytotoxic CD8+ T cells upon c-Myb upregulation was observed, which correlated with a pro-inflammatory tumor microenvironment and increased numbers of M1 polarized TAMs. Mechanistically, c-Myb upregulation in immunogenic MC38 colon cancer cells resulted in enhanced expression of immunomodulatory genes, including b2-microglobulin, interferon-β and decreased expression of the chemokine receptor CCR2. The observed increased counts of cytotoxic CD8+ T cells contributed to tumor growth attenuation. In poorly immunogenic CT26, LLC and B16-BL6 tumor cells, c-Myb upregulation did not affect immune responses. Interestingly, c-Myb upregulation has led to a reduced B16-BL6 tumor growth but it did not affect tumor growth of CT26 and LLC tumors. Altogether, we postulate that c-Myb functions as a tumor suppressor in a tumor cell-type specific manner and modulates anti-tumor immunity.
2023-07-28 | GSE232823 | GEO
Project description:The transcription factor c-Myb is overexpressed in many different types of solid tumors, including colorectal cancer. However, its exact role in tumorigenesis is unclear. In this study, we show that tumor-intrinsic c-Myb expression in mouse models of colon cancer and melanoma suppresses tumor growth. Although no differences in proliferation, apoptosis, and angiogenesis of tumors were evident in tumors with distinct levels of c-Myb expression, we observed changes in intratumoral immune cell infiltrates. MC38 tumors with upregulated c-Myb expression showed increased numbers of CD103+ dendritic cells and eosinophils, but decreased tumor-associated macrophages (TAM). Concomitantly, an increase in the number of activated cytotoxic CD8+ T cells upon c-Myb upregulation was observed, which correlated with a pro-inflammatory tumor microenvironment and increased numbers of M1 polarized TAMs. Mechanistically, c-Myb upregulation in immunogenic MC38 colon cancer cells resulted in enhanced expression of immunomodulatory genes, including those encoding β2-microglobulin and IFNβ, and decreased expression of the gene encoding the chemokine receptor CCR2. The increased numbers of activated cytotoxic CD8+ T cells contributed to tumor growth attenuation. In poorly immunogenic CT26, LLC, and B16-BL6 tumor cells, c-Myb upregulation did not affect the immunomodulatory gene expression. Despite this, c-Myb upregulation led to reduced B16-BL6 tumor growth but it did not affect tumor growth of CT26 and LLC tumors. Altogether, we postulate that c-Myb functions as a tumor suppressor in a tumor cell-type specific manner and modulates antitumor immunity.
| S-EPMC10548106 | biostudies-literature
Project description:Stem cells are maintained by transcriptional programs promoting self-renewal and repressing differentiation. Here, we show that the transcription factor Myb is essential for generating and maintaining stem cells within the CD8+ T-cell memory compartment. We found that, following viral infection, CD8+ T cells lacking Myb underwent terminal differentiation and exhibited impaired capacity to form CD62L+ stem cell-like memory cells. Myb acted both as a transcriptional activator of Tcf7 to enhance the development of memory cells and as a repressor of effector differentiation through Zeb2 suppression. Myb mutants’ complementation revealed that the Myb transactivation domain was necessary to restrain terminal differentiation, whereas the negative regulatory domain was critical for cell survival. Conversely, Myb overexpression enhanced CD8+ T-cell memory formation, polyfunctionality, and recall responses promoting curative antitumor immunity. These findings identify Myb as a pivotal regulator of CD8+ T-cell stemness and highlight the therapeutic potential of increasing Myb activity in CD8+ T cells.
2018-11-01 | GSE112049 | GEO
Project description:The transcription factor Myb enhances CD8+ T cell stemness and antitumor immunity
| PRJNA439010 | ENA
Project description:Abstract: Radiation therapy is a key component of the standard of care for glioblastoma (GBM). Although this treatment is known to trigger pro-inflammatory immune responses, it also results in several immune resistance mechanisms such as the upregulation of CD47 by tumors leading to avoidance of phagocytosis and the overexpression of PD-L1 in tumor-associated myeloid cells (TAMCs). Leveraging these RT-elicited processes, we generated a bispecific-lipid nanoparticle (B-LNP) that engaged TAMCs to glioma cells via anti-CD47/PD-L1 dual-ligation. We show that B-LNP blocked these two vital immune checkpoint molecules and promoted the phagocytic activity of TAMCs. In order to boost subsequent T cell recruitment and antitumor activity after tumor engulfment, the B-LNP was encapsulated with diABZI, a non-nucleotidyl agonist for stimulator of interferon genes (STING). In vivo treatment with the diABZI-loaded B-LNP induced a transcriptomic and metabolic switch in TAMCs, transforming them into potent antitumor effector cells, which induced T cell infiltration and activation of in the brain tumors. In preclinical murine glioma models, B-LNP therapy significantly potentiated the antitumor effects of radiotherapy, promoted brain tumor regression, and induced immunological memory against gliomas. The nano37 therapy was efficacious through both intra-tumoral and systemic delivery routes. In summary, our study shows a unique nanotechnology-based approach that hijacks multiple immune checkpoints to boost potent and long-lasting antitumor immunity against GBM.
2023-02-06 | ST002467 | MetabolomicsWorkbench
Project description:Earlier we have shown important roles of MYB in pancreatic tumor pathobiology. To better understand the role of MYB in the tumor microenvironment and identify MYB-associated secreted biomarker proteins, we conducted mass spectrometry analysis of the secretome from MYB-modulated and control pancreatic cancer cell lines. We also performed in silico analyses to determine MYB-associated biofunctions, gene networks and altered biological pathways. We further investigated the secreted proteins for their potential biomarker properties.
2021-09-08 | PXD015126 | Pride
Project description:Most E2F-binding sites repress transcription through the recruitment of Retinoblasoma (RB) family members until the end of the G1 cell-cycle phase. Although the MYB promoter contains an E2F-binding site, its transcription is activated shortly after the exit from quiescence, before RB family members inactivation, by unknown mechanisms. We had previously uncovered a nuclear factor distinct from E2F, Myb-sp, whose DNA-binding site overlapped the E2F element and had hypothesized that this factor might overcome the transcriptional repression of MYB by E2F-RB family members. We have purified Myb-sp and discovered that Myc-associated zinc finger proteins (MAZ) are major components. We show that various MAZ isoforms are present in Myb-sp and activate transcription via the MYB-E2F element. Moreover, while forced RB or p130 expression repressed the activity of a luciferase reporter driven by the MYB-E2F element, co-expression of MAZ proteins not only reverted repression, but also activated transcription. Finally, we show that MAZ binds the MYB promoter in vivo, that its binding site is critical for MYB transactivation, and that MAZ knockdown inhibits MYB expression during the exit from quiescence. Together, these data indicate that MAZ is essential to bypass MYB promoter repression by RB family members and to induce MYB expression.
2017-10-04 | PXD006857 | Pride
Project description:Oncolytic ORFV induces antitumor immunity
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Project description:scRNAseq-based unsupervised clustering and clonotyping revealed that Th1/17 and CCR6 SP clusters formed metacluster Th7R, which was distinct from Th1 or Th17, characterized by high expression of the IL-7 receptor. Use of this cluster to assess antitumor CD4+ T cell immunity from the peripheral blood and to predict the efficacy of immune checkpoint inhibitors will pave the way for novel antitumor immunotherapy strategies for patients.
2022-12-21 | GSE168844 | GEO
Project description:Local immunotherapy ideally stimulates immune responses against tumors while avoiding toxicities associated with systemic administration. Current strategies for tumor-targeted, gene-based delivery, however, are limited by adverse effects such as off-targeting or anti-vector immunity. We investigated the intratumoral administration of saline-formulated messenger (m)RNA encoding four cytokines that were identified as mediators of tumor regression across different tumor models: interleukin (IL)-12 single chain, interferon (IFN)-α, granulocyte-macrophage colony-stimulating factor, and IL-15 sushi. Effective antitumor activity of these cytokines relied on multiple immune cell populations and was accompanied by intratumoral IFN-γ induction, systemic antigen-specific T cell expansion, increased granzyme B+ T cell infiltration, and formation of immune memory. Antitumor activity extended beyond the treated lesions and inhibited growth of distant tumors as well as disseminated tumors. Combining the mRNAs with immunomodulatory antibodies enhanced antitumor responses in both injected and uninjected tumors, thus improving survival and tumor regression. Consequently, clinical testing of this cytokine-encoding mRNA mixture is now underway.
2021-07-10 | GSE179738 | GEO