Search results for "Microenvironment"
showing 10 items of 369 documents
Abstract 4981: Circulating mir-320 promotes immunosuppressive macrophages M2 phenotype associated with lung cancer progression
2018
Abstract INTRODUCTION miRNAs play a role in the complex network of signaling between cancer cells and tumor microenvironment. We previously reported the identification of diagnostic miRNA signatures (MSC) based on 24-miRNAs in plasma samples of lung cancer patients detected by low dose computed tomography (LDCT) screening. MATERIAL and METHODS To evaluate the potential origin of the miRNAs of the diagnostic signature, we analyzed their expression by real-time or digital PCR in both cells and conditioned medium (CM) from different cell types of the lung microenvironment as well as in plasma samples of heavy smokers and patients. Lung tissues and cell-blocks were analyzed by miRNAs in situ hy…
Abstract A24: Bone marrow hematopoietic adaptation as a sensor of early, pre-invasive, epithelial malignancy
2018
Abstract Tumor development and progression is in part dependent on the ability of bystander cells, mostly of bone marrow (BM) origin, to establish a pro-tumorigenic microenvironment. We hypothesized that signs of the cross-talk between elements of the tumor microenvironment and the BM can be identified in the very early phases of cancer development, being finalized to the instruction of a tumor-promoting hematopoiesis. By integrating in situ BM histopathological and immunophenotypical analyses with flow cytometry and gene expression profiling of hematopoietic populations in a spontaneous mouse model of breast carcinogenesis (MMTV/NeuT) we investigated the occurrence and quality of modificat…
Abstract 2141: Stromal SPARC deficiency skews prostate cancer toward neuroendocrine differentiation
2018
Abstract Tumor progression is a multifaceted process in which, complex interactions between tumor and different types of stromal cells and extracellular matrix components, actively contribute to its phenotypic heterogeneity. Among extracellular matrix proteins, secreted protein acidic and rich in cysteine (SPARC) has been deeply studied since conflicting reports have described its expression to be either increased or decreased in different cancer settings, also depending on whether it is produced by the neoplasm or by the neighboring stroma. Nevertheless, the different contribution of tumor- or stromal-derived SPARC in prostate tumor microenvironment has not been addressed at least for tumo…
Abstract 1847: Anti-GARP antibody DS-1055a augments antitumor immunity by depleting highly suppressive GARP+ regulatory T cells
2021
Abstract Immune checkpoint blockers (ICBs) have drastically changed the clinical care of cancer; however, the population of patients who can benefit is relatively small because of intrinsic or acquired resistance to immune therapy. To evade immune destruction, tumors exploit several distinct strategies including immunosuppressive cells such as regulatory T (Treg) cells. Treg cells, an essential component for maintaining self-tolerance, inhibit antitumor immunity, consequently hindering protective cancer immunosurveillance and hampering effective antitumor immune responses in tumor-bearing hosts. It is often reported that a high ratio of Treg cells to effector CD8+ T cells is associated with…
Abstract B290: Activation of the PD-1 pathway contributes to immune escape in EGFR-driven lung tumors.
2013
Abstract The recent clinical success of therapeutic blockade of the immune checkpoint Programmed Death (PD)-1 in advanced lung cancer patients suggests that mechanisms of immune escape may contribute to lung tumor pathogenesis. We identified a correlation between Epidermal Growth Factor Receptor (EGFR) pathway activation and a gene signature indicative of immunosuppression manifested by upregulation of PD-1, PD-L1, cytotoxic T lymphocyte antigen-4 (CTLA-4) and multiple tumor-promoting inflammatory cytokines. Accordingly, we identified a decrease in the number of cytotoxic T cells and an increase in markers of T cell exhaustion in genetically engineered mouse models (GEMMs) of EGFR-driven lu…
Human leukocyte elastase counteracts matrix metalloproteinase-7 induced apoptosis resistance of tumor cells.
2008
Matrix metalloproteinase-7 (MMP-7/Matrilysin) is a component of the tumor microenvironment associated with malignant progression. Its expression in tumors protects tumor cells from CD95-mediated apoptosis and the cytotoxic activity of tumor specific CD8(+) T cells. In the present study, we show that human leukocyte elastase (HLE) secreted by polymorphonuclear leukocytes cleaves MMP-7 resulting in loss of enzymatic activity. The anti-apoptotic effect of MMP-7 is reduced in the presence of HLE for CD95-, doxorubicin- and CTL-mediated apoptosis. Our data indicates that HLE may be a natural inactivator of MMP-7 which can counteract MMP-7-induced apoptosis resistance.
2.35 CD73-Generated Extracellular Adenosine Creates Microenvironmental Conditions Favoring Growth and Survival of Chronic Lymphocytic Leukemia Cells
2011
Abstract Abstract 621 CD39 (ecto-nucleoside-triphosphate-diphosphohydrolase-1) and CD73 (5'-nucleotidase) are surface enzymes with extracellular catalytic sites. CD39 hydrolyses ATP/ADP to AMP, which is then converted to adenosine (ADO) by CD73. Once ADO is released in the extracellular milieu, it may re-enter the cell or engage different types of purinergic receptors, eliciting potent autocrine and paracrine cytoprotective, anti-inflammatory and immunosuppressive effects. Several lines of evidence suggest that the tumor microenvironment is marked by increased turnover of extracellular nucleotides and nucleosides, as well as by upregulation of ecto-enzymes that dismantle them. These alterat…
Abstract LB061: On-target peripheral and tumor immune microenvironment modulation in patients treated with lacnotuzumab (anti-CSF1, MCS110) + spartal…
2021
Abstract Background: The CSF-1/CSF-1R (colony-stimulating factor-1) pathway plays a significant role in the tumor microenvironment via regulation of tumor-associated macrophages (TAMs). Lacnotuzumab (MCS110) is a humanized monoclonal antibody against CSF-1. Lacnotuzumab may counteract the tumor suppressive microenvironment induced by CSF-1, potentially enhancing the efficacy of PD-1 inhibition. Methods: MCS110Z2102 is a phase 1b/2 study in cancer patients with advanced malignancies treated by lacnotuzumab combined with the PD-1 inhibitor spartalizumab. Eligible patients with previously treated advanced/metastatic solid tumors received 1, 3, 5, 7.5 and 10 mg/kg intravenous doses of lacnotuzu…
Exploring the Dynamic Crosstalk between the Immune System and Genetics in Gastrointestinal Stromal Tumors
2022
Gastrointestinal Stromal Tumors (GISTs) represent a paradigmatic model of oncogene addiction. Despite the well-known impact of the mutational status on clinical outcomes, we need to expand our knowledge to other factors that influence behavior heterogeneity in GIST patients. A growing body of studies has revealed that the tumor microenvironment (TME), mostly populated by tumor-associated macrophages (TAMs) and lymphocytes (TILs), and stromal differentiation (SD) have a significant impact on prognosis and response to treatment. Interestingly, even though the current knowledge of the role of immune response in this setting is still limited, recent pre-clinical and clinical data have highlight…
Prognostic significance of spatial and density analysis of T lymphocytes in colorectal cancer.
2022
Abstract Background Although high T cell density is a strong favourable prognostic factor in colorectal cancer, the significance of the spatial distribution of T cells is incompletely understood. We aimed to evaluate the prognostic significance of tumour cell-T cell co-localisation and T cell densities. Methods We analysed CD3 and CD8 immunohistochemistry in a study cohort of 983 colorectal cancer patients and a validation cohort (N = 246). Individual immune and tumour cells were identified to calculate T cell densities (to derive T cell density score) and G-cross function values, estimating the likelihood of tumour cells being co-located with T cells within 20 µm radius (to derive T cell p…