Papers by Silvia Sartoris
Journal for ImmunoTherapy of Cancer, 2022
BackgroundPancreatic ductal adenocarcinoma (PDAC) is one of the deadliest tumors owing to its rob... more BackgroundPancreatic ductal adenocarcinoma (PDAC) is one of the deadliest tumors owing to its robust desmoplasia, low immunogenicity, and recruitment of cancer-conditioned, immunoregulatory myeloid cells. These features strongly limit the success of immunotherapy as a single agent, thereby suggesting the need for the development of a multitargeted approach. The goal is to foster T lymphocyte infiltration within the tumor landscape and neutralize cancer-triggered immune suppression, to enhance the therapeutic effectiveness of immune-based treatments, such as anticancer adoptive cell therapy (ACT).MethodsWe examined the contribution of immunosuppressive myeloid cells expressing arginase 1 and nitric oxide synthase 2 in building up a reactive nitrogen species (RNS)-dependent chemical barrier and shaping the PDAC immune landscape. We examined the impact of pharmacological RNS interference on overcoming the recruitment and immunosuppressive activity of tumor-expanded myeloid cells, which...
T acute lymphoblastic leukemia (T-ALL) cells arise inside the thymus and, in most cases, migrate ... more T acute lymphoblastic leukemia (T-ALL) cells arise inside the thymus and, in most cases, migrate to the bone marrow (BM) where proliferate and expand. Thymic and BM microenvironments play a fundamental role in controlling survival, proliferation, and metabolic functions of T- ALL cells. In this study we explored whether BM-derived stroma can modulate in primary T-ALL cells the production of interleukin (IL)-8, a cytokine that contributes to human cancer progression. To this aim, we performed lympho-stromal co-cultures between normal human BM stro- ma and primary T-ALL cells. After co-culture, we isolated T-ALL from BM cells by fluorescence activated cell sorter (FACS) and analyzed them for the presence of IL-8 mRNA. The interaction with BM-stroma induced a significant increase of IL-8 mRNA in leukemic blasts. The functional blockade of CXCL12 receptor, CXCR4, but not TNF or IL-1R, complete- ly impaired IL-8 induction, thus indicating the involvement of CXCL12/CXCR4 axis in the BM-mediated IL-8 production. In addition, treatment of primary T-ALL cells with recombinant SDF-1 induced a significant increased production of IL-8. The induction was specific for IL-8, as IL-1, IL-6, TNF, or IL-10 production was unchanged after CXCL12 treatment. IL-8 increased expression was also confirmed at mRNA level. Finally, we showed that the activation of nuclear factor (NF)-\u3baB and c-Jun, which represents fundamental pathway in the induc- tion of IL-8 gene transcription, was required for the CXCL12-mediated IL-8 production. Our results implicate a novel function for CXCL12 in regulating IL-8 expression in T-ALL through the activation of the NF-kap- paB and c-Jun pathways. We propose that this novel function of CXCL12 in inducing IL-8 production in leukemia cells may be relevant for the expansion of T-ALL inside the BM microenvironments
Pancreatic Ductal Adenocarcinoma (PDAC) is a fatal neoplasia of the exocrine pancreas with a high... more Pancreatic Ductal Adenocarcinoma (PDAC) is a fatal neoplasia of the exocrine pancreas with a high mortality rate. PDAC microenvironment is heterogeneous and has been found to play a crucial role in carcinogenesis and negative response to treatments. Moreover, early biomarkers are missing. Biomimetic models of PDAC are thus desirable to understand the underlying molecular mechanisms and to approach new therapies. In this view, the development of 3D tumor models via tissue engineering can offer valuable opportunities . The aim of this study was to investigate the interactions between PDAC cells and different scaffolds to generate new 3D in vitro models for the study of tumor growth and development
Mesenchymal stem cells (MSCs) are adherent, multipotent, non-hematopoietic progenitor cells, whic... more Mesenchymal stem cells (MSCs) are adherent, multipotent, non-hematopoietic progenitor cells, which have multilineage differentiation potential. Exogenously administered MSCs have been shown to poorly engraft in rodent adult healthy tissues, although they preferentially survive and proliferate in the presence of malignant cells and become stromal fibroblasts supporting tumor cell growth. Thus MSCs are attractive candidates to deliver genes of immunologically active molecules to the tumor environment in vivo and to enhance specific immune responses. IFN\u3b1 has been used for the last 20 years in the maintenance therapy of multiple myeloma and it increases both progression-free and overall survival in those patient that tolerate IFN\u3b1 maintenance therapy and when transplantation is not possible. We have transduced MSCs derived from the bone marrow of Balb/c mice with lentiviral-derived vectors to express mouse IFN\u3b1 (MSCs/IFN\u3b1) and analyzed their effect on subcutaneous tumor growth in vivo, in a plasmacytoma-derived mouse tumor model. The results can be summarized as follows: 1. coinjection of MSCs/IFN\u3b1 with myeloma cells resulted in a statistically significant delay in the onset of palpable tumors (tumor incidence of 25% at day 50, whereas myeloma cells alone or coinjected with wild type MSCs showed tumor incidence of 100% 10-15 days after injection); 2. weekly delivery of MSCs/IFN\u3b1 induced a statistically significant decrease of tumor development (tumor incidence: 20% at day 50); 3. myeloma cells transduced with IFN\u3b1 showed in vivo tumor growth rates faster than those of wild type myeloma co-injected with MSC/IFN\u3b1, in a statistically significant manner (tumor incidence of 70% at day 50). These results indicate that MSCs secreting IFN\u3b1 can be useful tools for IFN\u3b1 gene therapy of tumors
Regulation of CD5 gene expression in interspecies human x mouse T cell hybrid
The mouse prostatic adenocarcinoma tumorigenic cell lines TRAMP-C1 and TRAMP-C2 represent a suita... more The mouse prostatic adenocarcinoma tumorigenic cell lines TRAMP-C1 and TRAMP-C2 represent a suitable animal model to study the role of major histocompatibility class-I (MHC-I) molecules expression in protection against tumor development and progression in vivo. In these cell lines, MHC-I expression decreases after time of in vitro cell culture, but it can be restored by treatment with IFN-\u3b3. We have transduced TRAMP-C2 cells with the cDNA of the co-stimulatory molecule B7-1. TRAMP-C2/B7 transfectants showed impaired growth in vivo, but they did not elicit a protective response against TRAMP-C2 parental tumor, unless after treatment with IFN-\u3b3 prior to injection. IFN-\u3b3 is an inducer of some components of the MHC-I antigen processing and presentation machinery (APM). IFN-\u3b3 is also an antagonist of the immunosuppressant activity of TGF-\u3b2, largely produced by TRAMP-C2. Thus, immunization with TRAMP-C2/B7 conferred protection against TRAMP-C2-derived tumors in function of the IFN-\u3b3-mediated fine-tuned modulation of either APM expression or TGF-\u3b2 signaling. To explore possible clinical traslation of these results we attempted to deliver IFN-\u3b3 to TRAMP-C2 tumor growth site by means of genetically engineered mesenchymal stem cells (MSCs) secreting IFN-\u3b3. This approach produced results matching those obtained with IFN-\u3b3-treated TRAMP-C2 cells
Cancer of Vater's ampulla: molecular pathogenesis and prognosi
Cells, 2021
Myeloid-derived suppressor cells (MDSCs) constitute a plastic and heterogeneous cell population a... more Myeloid-derived suppressor cells (MDSCs) constitute a plastic and heterogeneous cell population among immune cells within the tumour microenvironment (TME) that support cancer progression and resistance to therapy. During tumour progression, cancer cells modify their metabolism to sustain an increased energy demand to cope with uncontrolled cell proliferation and differentiation. This metabolic reprogramming of cancer establishes competition for nutrients between tumour cells and leukocytes and most importantly, among tumour-infiltrating immune cells. Thus, MDSCs that have emerged as one of the most decisive immune regulators of TME exhibit an increase in glycolysis and fatty acid metabolism and also an upregulation of enzymes that catabolise essential metabolites. This complex metabolic network is not only crucial for MDSC survival and accumulation in the TME but also for enhancing immunosuppressive functions toward immune effectors. In this review, we discuss recent progress in th...
Frontiers in Immunology, 2021
Plasticity and adaptation to environmental stress are the main features that tumor and immune sys... more Plasticity and adaptation to environmental stress are the main features that tumor and immune system share. Except for intrinsic and high-defined properties, cancer and immune cells need to overcome the opponent’s defenses by activating more effective signaling networks, based on common elements such as transcriptional factors, protein-based complexes and receptors. Interestingly, growing evidence point to an increasing number of proteins capable of performing diverse and unpredictable functions. These multifunctional proteins are defined as moonlighting proteins. During cancer progression, several moonlighting proteins are involved in promoting an immunosuppressive microenvironment by reprogramming immune cells to support tumor growth and metastatic spread. Conversely, other moonlighting proteins support tumor antigen presentation and lymphocytes activation, leading to several anti-cancer immunological responses. In this light, moonlighting proteins could be used as promising new p...
Vaccine, 2018
Most active cancer immunotherapies able to induce a long-lasting protection against tumours are b... more Most active cancer immunotherapies able to induce a long-lasting protection against tumours are based on the activation of tumour-specific cytotoxic T lymphocytes (CTLs). Cell death by hyperthermia induces apoptosis followed by secondary necrosis, with the production of factors named ''danger associated molecular pattern" (DAMP) molecules (DAMPs), that activate dendritic cells (DCs) to perform antigen uptake, processing and presentation, followed by CTLs cross priming. In many published studies, hyperthermia treatment of tumour cells is performed at 42-45°C; these temperatures mainly promote cell surface expression of DAMPs. Treatment at 56°C of tumour cells was shown to induce DAMPs secretion rather than their cell surface expression, improving DC activation and CTL cross priming in vitro. Thus we tested the relevance of this finding in vivo on the generation of a tumour-specific memory immune response, in the TRAMP-C2 mouse prostate carcinoma transplantable model. TRAMP-C2 tumour cells treated at 56°C were able not only to activate DCs in vitro but also to trigger a tumour-specific CTLdependent immune response in vivo. Prophylactic vaccination with 56°C-treated TRAMP-C2 tumour cells alone provided protection against TRAMP-C2 tumour growth in vivo, whilst in the therapeutic regimen, control of tumour growth was achieved combining immunization with adjuvant chemotherapy.
Frontiers in Oncology, 2020
Tumor metastases represent the major cause of cancer-related mortality, confirming the urgent nee... more Tumor metastases represent the major cause of cancer-related mortality, confirming the urgent need to identify key molecular pathways and cell-associated networks during the early phases of the metastatic process to develop new strategies to either prevent or control distal cancer spread. Several data revealed the ability of cancer cells to establish a favorable microenvironment, before their arrival in distant organs, by manipulating the cell composition and function of the new host tissue where cancer cells can survive and outgrow. This predetermined environment is termed "pre-metastatic niche" (pMN). pMN development requires that tumor-derived soluble factors, like cytokines, growth-factors and extracellular vesicles, genetically and epigenetically reprogram not only resident cells (i.e., fibroblasts) but also non-resident cells such as bone marrow-derived cells. Indeed, by promoting an "emergency" myelopoiesis, cancer cells switch the steady state production of blood cells toward the generation of pro-tumor circulating myeloid cells defined as myeloid-derived suppressor cells (MDSCs) able to sustain tumor growth and dissemination. MDSCs are a heterogeneous subset of myeloid cells with immunosuppressive properties that sustain metastatic process. In this review, we discuss current understandings of how MDSCs shape and promote metastatic dissemination acting in each fundamental steps of cancer progression from primary tumor to metastatic disease.
Journal for ImmunoTherapy of Cancer, 2019
Background: Pancreatic ductal adenocarcinoma (PDAC) is a highly devastating disease with an overa... more Background: Pancreatic ductal adenocarcinoma (PDAC) is a highly devastating disease with an overall 5-year survival rate of less than 8%. New evidence indicates that PDAC cells release pro-inflammatory metabolites that induce a marked alteration of normal hematopoiesis, favoring the expansion and accumulation of myeloid-derived suppressor cells (MDSCs). We report here that PDAC patients show increased levels of both circulating and tumor-infiltrating MDSC-like cells. Methods: The frequency of MDSC subsets in the peripheral blood was determined by flow cytometry in three independent cohorts of PDAC patients (total analyzed patients, n = 117). Frequency of circulating MDSCs was correlated with overall survival of PDAC patients. We also analyzed the frequency of tumor-infiltrating MDSC and the immune landscape in fresh biopsies. Purified myeloid cell subsets were tested in vitro for their T-cell suppressive capacity. Results: Correlation with clinical data revealed that MDSC frequency was significantly associated with a shorter patients' overall survival and metastatic disease. However, the immunosuppressive activity of purified MDSCs was detectable only in some patients and mainly limited to the monocytic subset. A transcriptome analysis of the immunosuppressive M-MDSCs highlighted a distinct gene signature in which STAT3 was crucial for monocyte reprogramming. Suppressive M-MDSCs can be characterized as circulating STAT3/arginase1-expressing CD14 + cells. Conclusion: MDSC analysis aids in defining the immune landscape of PDAC patients for a more appropriate diagnosis, stratification and treatment.
Frontiers in Immunology, 2019
Cancer immunotherapy relies on either restoring or activating the function of adaptive immune cel... more Cancer immunotherapy relies on either restoring or activating the function of adaptive immune cells, mainly CD8 + T lymphocytes. Despite impressive clinical success, cancer immunotherapy remains ineffective in many patients due to the establishment of tumor resistance, largely dependent on the nature of tumor microenvironment. There are several cellular and molecular mechanisms at play, and the goal is to identify those that are clinically significant. Among the hematopoietic-derived cells, monocytes are endowed with high plasticity, responsible for their pro-and anti-tumoral function. Indeed, monocytes are involved in several cancer-associated processes such as immune-tolerance, metastatic spread, neoangiogenesis, and chemotherapy resistance; on the other hand, by presenting cancer-associated antigens, they can also promote and sustain anti-tumoral T cell response. Recently, by high throughput technologies, new findings have revealed previously underappreciated, profound transcriptional, epigenetic, and metabolic differences among monocyte subsets, which complement and expand our knowledge on the monocyte ontogeny, recruitment during steady state, and emergency hematopoiesis, as seen in cancer. The subdivision into discrete monocytes subsets, both in mice and humans, appears an oversimplification, whereas continuum subsets development is best for depicting the real condition. In this review, we examine the evidences sustaining the existence of a monocyte heterogeneity along with functional activities, at the primary tumor and at the metastatic niche. In particular, we describe how tumor-derived soluble factors and cell-cell contact reprogram monocyte function. Finally, we point out the role of monocytes in preparing and shaping the metastatic niche and describe relevant targetable molecules altering monocyte activities. We think that exploiting monocyte complexity can help identifying key pathways important for the treatment of cancer and several conditions where these cells are involved.
Nature Communications, 2018
Immunosuppression is a hallmark of tumor progression, and treatments that inhibit or deplete mono... more Immunosuppression is a hallmark of tumor progression, and treatments that inhibit or deplete monocytic myeloid-derived suppressive cells could promote anti-tumor immunity. c-FLIP is a central regulator of caspase-8-mediated apoptosis and necroptosis. Here we show that low-dose cytotoxic chemotherapy agents cause apoptosis linked to c-FLIP down-regulation selectively in monocytes. Enforced expression of c-FLIP or viral FLIP rescues monocytes from cytotoxicity and concurrently induces potent immunosuppressive activity, in T cell cultures and in vivo models of tumor progression and immunotherapy. FLIP-transduced human blood monocytes can suppress graft versus host disease. Neither expression of FLIP in granulocytes nor expression of other anti-apoptotic genes in monocytes conferred immunosuppression, suggesting that FLIP effects on immunosuppression are specific to monocytic lineage and distinct from death inhibition. Mechanistically, FLIP controls a broad transcriptional program, part...
Oncotarget, 2017
Telomerase (TERT) is a ribonucleoprotein enzyme that preserves the molecular organization at the ... more Telomerase (TERT) is a ribonucleoprotein enzyme that preserves the molecular organization at the ends of eukaryotic chromosomes. Since TERT deregulation is a common step in leukaemia, treatments targeting telomerase might be useful for the therapy of hematologic malignancies. Despite a large spectrum of potential drugs, their bench-to-bedside translation is quite limited, with only a therapeutic vaccine in the clinic and a telomerase inhibitor at late stage of preclinical validation. We recently demonstrated that the adoptive transfer of T cell transduced with an HLA-A2-restricted T-cell receptor (TCR), which recognize human TERT with high avidity, controls human B-cell chronic lymphocytic leukaemia (B-CLL) progression without severe side-effects in humanized mice. In the present report, we show the ability of our approach to limit the progression of more aggressive leukemic pathologies, such as acute myeloid leukaemia (AML) and B-cell acute lymphoblastic leukaemia (B-ALL). Together, our findings demonstrate that TERT-based adoptive cell therapy is a concrete platform of T cell-mediated immunotherapy for leukaemia treatment.
Oncotarget, 2017
In the late B cell differentiation stages, miRNAs expression modifications promoting or inhibitin... more In the late B cell differentiation stages, miRNAs expression modifications promoting or inhibiting key pathways are only partially defined. We isolated 29 CD19 + human B cell samples at different stages of differentiation: B cells from peripheral blood; naïve, germinal center (GC) and subepithelial (SE) B cells from tonsils. SE cells were further split in activated and resting B cell. The miRNA expression profile of these B cells was assessed by microarray analysis and selected miRNAs were validated by quantitative RT-PCR and in situ hybridization on normal tonsils. The comparison of all samples showed changes in 107 miRNAs in total. Among 48 miRNAs differentially expressed in naïve, GC and SE cells, we identified 8 miRNAs: mir-323, mir-138, mir-9*, mir-211, mir-149, mir-373, mir-135a and mir-184, strictly specific to follicular cells that had never been implicated before in late stages of B cell development. Moreover, we unveiled 34 miRNAs able to discriminate between CD5 − activated B cells and resting B cells. The miRNAs profile of CD5 − resting B cells showed a higher similarity to naïve CD5 + than CD5 − activated B cells. Finally, network analysis on shortest paths connecting gene targets suggested ZEB1 and TP53 as key miRNA targets during the follicular differentiation pathway. These data confirm and extend our knowledge on the miRNAs-related regulatory pathways involved in the late B cell maturation.
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Papers by Silvia Sartoris