Publications by authors named "Sabina Sangaletti"

55 Publications

Modulation of PD-1/PD-L1 axis in myeloid-derived suppressor cells by anti-cancer treatments.

Cell Immunol 2021 Feb 4;362:104301. Epub 2021 Feb 4.

Molecular Immunology Unit, Department of Research, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy. Electronic address:

Immuno checkpoint blockade (ICB) targeting the PD-1/PD-L1 axis is the main breakthrough for the treatment of several cancers. Nevertheless, not all patients benefit from this treatment and clinical response not always correlates with PD-L1 expression by tumor cells. The tumor microenvironment, including myeloid derived suppressor cells (MDSCs), can influence therapeutic resistance to ICB. MDSCs also express PD-L1, which contributes to their suppressive activity. Moreover, anticancer therapies including chemotherapy, radiotherapy, hormone- and targeted- therapies can modulate MDSCs recruitment, activity and PD-L1 expression. Such effects can be induced also by innovative anticancer treatments targeting metabolism and lifestyle. The outcome on cancer progression can be either positive or negative, depending on tumor type, treatment schedule and possible combination with ICB. Further studies are needed to better understand the effects of cancer therapies on the PD-1/PD-L1 axis, to identify patients that could benefit from combinatorial regimens including ICB or that rather should avoid it.
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http://dx.doi.org/10.1016/j.cellimm.2021.104301DOI Listing
February 2021

A combination of extracellular matrix- and interferon-associated signatures identifies high-grade breast cancers with poor prognosis.

Mol Oncol 2021 Feb 1. Epub 2021 Feb 1.

Unit of Immunotherapy and Anticancer Innovative Therapeutics, Department of Medical Oncology and Hematology, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.

Breast cancer (BC) is a heterogeneous disease in which the tumor microenvironment (TME) seems to impact the clinical outcome. Here, we investigated whether a combination of gene expression signatures relating to both the structural and immune TME aspects can help predict prognosis in women with high-grade BC (HGBC). Thus, we focused on a combined molecular biomarker variable that involved extracellular matrix (ECM)-associated gene expression (ECM3 signature) and interferon (IFN)-associated metagene (IFN metagene) expression. In 97 chemo-naive HGBCs from the METABRIC dataset, the dichotomous ECM3/IFN (dECIF) variable identified a group of high-risk patients (ECM3 /IFN vs other; hazard ratio = 3.2, 95% confidence interval: 1.5-6.7). Notably, ECM3 /IFN tumors showed low tumor-infiltrating lymphocytes, high levels of CD33-positive cells, absence of PD-1 expression, or low expression of PD-L1, as suggested by immune profiles and immune-histochemical analysis on an independent cohort of 131 HGBCs. To make our results transferable to clinical use, we refined the dECIF biomarker using reduced ECM3 and IFN signatures; notably, the prognostic value of this reduced dECIF was comparable to that of the original dECIF. After validation in a new BC cohort, reduced dECIF was translated into a robust qPCR classifier for real-world clinical use.
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http://dx.doi.org/10.1002/1878-0261.12912DOI Listing
February 2021

Intra-tumour heterogeneity of diffuse large B-cell lymphoma involves the induction of diversified stroma-tumour interfaces.

EBioMedicine 2020 Nov 20;61:103055. Epub 2020 Oct 20.

Tumor Immunology Unit, University of Palermo, Palermo, Italy; Tumor and Microenvironment Histopathology Unit, IFOM, FIRC Institute of Molecular Oncology, Milan, Italy. Electronic address:

Background: Intra-tumour heterogeneity in lymphoid malignancies encompasses selection of genetic events and epigenetic regulation of transcriptional programs. Clonal-related neoplastic cell populations are unsteadily subjected to immune editing and metabolic adaptations within different tissue microenvironments. How tissue-specific mesenchymal cells impact on the diversification of aggressive lymphoma clones is still unknown.

Methods: Combining in situ quantitative immunophenotypical analyses and RNA sequencing we investigated the intra-tumour heterogeneity and the specific mesenchymal modifications that are associated with A20 diffuse large B-cell lymphoma (DLBCL) cells seeding of different tissue microenvironments. Furthermore, we characterized features of lymphoma-associated stromatogenesis in human DLBCL samples using Digital Spatial Profiling, and established their relationship with prognostically relevant variables, such as MYC.

Findings: We found that the tissue microenvironment casts a relevant influence over A20 transcriptional landscape also impacting on Myc and DNA damage response programs. Extending the investigation to mice deficient for the matricellular protein SPARC, a stromal prognostic factor in human DLBCL, we demonstrated a different immune imprint on A20 cells according to stromal Sparc proficiency. Through Digital Spatial Profiling of 87 immune and stromal genes on human nodal DLBCL regions characterized by different mesenchymal composition, we demonstrate intra-lesional heterogeneity arising from diversified mesenchymal contextures and impacting on the stromal and immune milieu.

Interpretation: Our study provides experimental evidence that stromal microenvironment generates topological determinants of intra-tumour heterogeneity in DLBCL involving key transcriptional pathways such as Myc expression, damage response programs and immune checkpoints.

Funding: This study has been supported by the Italian Foundation for Cancer Research (AIRC) (grants 15999 and 22145 to C. Tripodo) and by the University of Palermo.
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http://dx.doi.org/10.1016/j.ebiom.2020.103055DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7581880PMC
November 2020

A Spatially Resolved Dark- versus Light-Zone Microenvironment Signature Subdivides Germinal Center-Related Aggressive B Cell Lymphomas.

iScience 2020 Oct 16;23(10):101562. Epub 2020 Sep 16.

Hematopathology Unit, European Institute of Oncology, Milan, Italy.

We applied digital spatial profiling for 87 immune and stromal genes to lymph node germinal center (GC) dark- and light-zone (DZ/LZ) regions of interest to obtain a differential signature of these two distinct microenvironments. The spatially resolved 53-genes signature, comprising key genes of the DZ mutational machinery and LZ immune and mesenchymal milieu, was applied to the transcriptomes of 543 GC-related diffuse large B cell lymphomas and double-hit (DH) lymphomas. According to the DZ/LZ signature, the GC-related lymphomas were sub-classified into two clusters. The subgroups differed in the distribution of DH cases and survival, with most DH displaying a distinct DZ-like profile. The clustering analysis was also performed using a 25-genes signature composed of genes positively enriched in the non-B, stromal sub-compartments, for the first time achieving DZ/LZ discrimination based on stromal/immune features. The report offers new insight into the GC microenvironment, hinting at a DZ microenvironment of origin in DH lymphomas.
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http://dx.doi.org/10.1016/j.isci.2020.101562DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7522121PMC
October 2020

Circulating T-cell Immunosenescence in Patients with Advanced Non-small Cell Lung Cancer Treated with Single-agent PD-1/PD-L1 Inhibitors or Platinum-based Chemotherapy.

Clin Cancer Res 2021 Jan 4;27(2):492-503. Epub 2020 Sep 4.

Gustave Roussy Cancer Campus, Laboratory of Immunomonitoring in Oncology, CNRS-UMS 3655 and INSERM-US23, Villejuif, France.

Purpose: CD28, CD57, and KLRG1 have been previously identified as markers of T-cell immunosenescence. The impact of immunosenescence on anti-PD(L)-1 (ICI) or platinum-based chemotherapy (PCT) in patients with advanced non-small cell lung cancer (aNSCLC) is unknown.

Experimental Design: The percentage of CD28, CD57, KLRG1 among CD8 T cells [senescent immune phenotype (SIP)] was assessed by flow cytometry on blood from patients with aNSCLC before single-agent ICI (discovery cohort). A SIP cut-off was identified by log-rank maximization method and patients with aNSCLC treated with ICI (validation cohort) or PCT were classified accordingly. Proliferation and functional properties of SIP CD8 T cells were assessed .

Results: In the ICI discovery cohort ( = 37), SIP cut-off was 39.5%, 27% of patients were SIP. In the ICI validation cohort ( = 46), SIP status was found in 28% of patients and significantly correlated with worse objective response rate (ORR; 0% vs. 30%, = 0.04), median progression-free survival (PFS) [1.8 (95% confidence interval (CI), 1.3-NR) vs. 6.4 (95% CI, 2-19) months, = 0.009] and median overall survival, OS [2.8 (95% CI, 2.0-NR) vs. 20.8 (95% CI, 6.0-NR) months, = 0.02]. SIP status was significantly associated with circulating specific immunephenotypes, lower CD8 T cells proliferation, lower IL2 and higher TNFα and IFNγ production. In the ICI-pooled population ( = 83), SIP status did not correlate with any clinical characteristics and it was associated with significantly worse ORR, PFS, and OS. In PCT cohort ( = 61), 11% of patients were SIP. SIP status did not correlate with outcomes upon PCT.

Conclusions: Circulating T-cell immunosenescence is observed in up to 28% of patients with aNSCLC and correlates with lack of benefit from ICI but not from PCT..
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http://dx.doi.org/10.1158/1078-0432.CCR-20-1420DOI Listing
January 2021

Neutralization of extracellular NAMPT (nicotinamide phosphoribosyltransferase) ameliorates experimental murine colitis.

J Mol Med (Berl) 2020 04 27;98(4):595-612. Epub 2020 Apr 27.

Department of Pharmaceutical Sciences, Università degli Studi di Pavia, 27100, Pavia, Italy.

Extracellular nicotinamide phosphoribosyltransferase (eNAMPT) is increased in inflammatory bowel disease (IBD) patients, and its serum levels correlate with a worse prognosis. In the present manuscript, we show that eNAMPT serum levels are increased in IBD patients that fail to respond to anti-TNFα therapy (infliximab or adalimumab) and that its levels drop in patients that are responsive to these therapies, with values comparable with healthy subjects. Furthermore, eNAMPT administration in dinitrobenzene sulfonic acid (DNBS)-treated mice exacerbates the symptoms of colitis, suggesting a causative role of this protein in IBD. To determine the druggability of this cytokine, we developed a novel monoclonal antibody (C269) that neutralizes in vitro the cytokine-like action of eNAMPT and that reduces its serum levels in rodents. Of note, this newly generated antibody is able to significantly reduce acute and chronic colitis in both DNBS- and dextran sulfate sodium (DSS)-induced colitis. Importantly, C269 ameliorates the symptoms by reducing pro-inflammatory cytokines. Specifically, in the lamina propria, a reduced number of inflammatory monocytes, neutrophils, Th1, and cytotoxic T lymphocytes are found upon C269 treatment. Our data demonstrate that eNAMPT participates in IBD and, more importantly, that eNAMPT-neutralizing antibodies are endowed with a therapeutic potential in IBD. KEY MESSAGES: What are the new findings? Higher serum eNAMPT levels in IBD patients might decrease response to anti-TNF therapy. The cytokine-like activity of eNAMPT may be neutralized with a monoclonal antibody. Neutralization of eNAMPT ameliorates acute and chronic experimental colitis. Neutralization of eNAMPT limits the expression of IBD inflammatory signature. Neutralization of eNAMPT impairs immune cell infiltration in lamina propria.
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http://dx.doi.org/10.1007/s00109-020-01892-0DOI Listing
April 2020

Tumor-Derived Prostaglandin E2 Promotes p50 NF-κB-Dependent Differentiation of Monocytic MDSCs.

Cancer Res 2020 07 7;80(13):2874-2888. Epub 2020 Apr 7.

Department of Pharmaceutical Sciences, Università del Piemonte Orientale "Amedeo Avogadro", Novara, Italy.

Myeloid-derived suppressor cells (MDSC) include immature monocytic (M-MDSC) and granulocytic (PMN-MDSC) cells that share the ability to suppress adaptive immunity and to hinder the effectiveness of anticancer treatments. Of note, in response to IFNγ, M-MDSCs release the tumor-promoting and immunosuppressive molecule nitric oxide (NO), whereas macrophages largely express antitumor properties. Investigating these opposing activities, we found that tumor-derived prostaglandin E2 (PGE2) induces nuclear accumulation of p50 NF-κB in M-MDSCs, diverting their response to IFNγ toward NO-mediated immunosuppression and reducing TNFα expression. At the genome level, p50 NF-κB promoted binding of STAT1 to regulatory regions of selected IFNγ-dependent genes, including inducible nitric oxide synthase (Nos2). In agreement, ablation of p50 as well as pharmacologic inhibition of either the PGE2 receptor EP2 or NO production reprogrammed M-MDSCs toward a NOS2/TNFα phenotype, restoring the antitumor activity of IFNγ. Our results indicate that inhibition of the PGE2/p50/NO axis prevents MDSC-suppressive functions and restores the efficacy of anticancer immunotherapy. SIGNIFICANCE: Tumor-derived PGE2-mediated induction of nuclear p50 NF-κB epigenetically reprograms the response of monocytic cells to IFNγ toward an immunosuppressive phenotype, thus retrieving the anticancer properties of IFNγ. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/80/13/2874/F1.large.jpg.
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http://dx.doi.org/10.1158/0008-5472.CAN-19-2843DOI Listing
July 2020

Transcriptional Profiles and Stromal Changes Reveal Bone Marrow Adaptation to Early Breast Cancer in Association with Deregulated Circulating microRNAs.

Cancer Res 2020 02 27;80(3):484-498. Epub 2019 Nov 27.

Molecular Immunology Unit, Department of Research, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.

The presence of a growing tumor establishes a chronic state of inflammation that acts locally and systemically. Bone marrow responds to stress signals by expanding myeloid cells endowed with immunosuppressive functions, further fostering tumor growth and dissemination. How early in transformation the cross-talk with the bone marrow begins and becomes detectable in blood is unknown. Here, gene expression profiling of the bone marrow along disease progression in a spontaneous model of mammary carcinogenesis demonstrates that transcriptional modifications in the hematopoietic compartment occurred as early as preinvasive disease stages. The transcriptional profile showed downregulation of adaptive immunity and induction of programs related to innate immunity and response to danger signals triggered by activating transcription factor 3. Transcriptional reprogramming was paralleled by the expansion of myeloid populations at the expense of erythroid and B lymphoid fractions. Hematopoietic changes were associated with modifications of the bone marrow stromal architecture through relocalization and increased density in the interstitial area of Nestin mesenchymal cells expressing CXCL12 and myeloid cells expressing CXCL12 receptor CXCR4. These early events were concomitant with deregulation of circulating miRNAs, which were predicted regulators of transcripts downregulated in the bone marrow and involved in lymphoid differentiation and activation. These data provide a link between sensing of peripheral cancer initiation by the bone marrow and hematopoietic adaptation to distant noxia through transcriptional rewiring toward innate/inflammatory response programs. SIGNIFICANCE: The bone marrow senses distant tissue transformation at premalignant/preinvasive stages, suggesting that circulating messengers, intercepted in the blood, could serve as early diagnostic markers.
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http://dx.doi.org/10.1158/0008-5472.CAN-19-1425DOI Listing
February 2020

A luminal EF-hand mutation in STIM1 in mice causes the clinical hallmarks of tubular aggregate myopathy.

Dis Model Mech 2019 12 3;13(2). Epub 2019 Dec 3.

Department of Pharmaceutical Sciences, University of Piemonte Orientale, Via Bovio 6, Novara 28100, Italy

STIM and ORAI proteins play a fundamental role in calcium signaling, allowing for calcium influx through the plasma membrane upon depletion of intracellular stores, in a process known as store-operated Ca entry. Point mutations that lead to gain-of-function activity of either STIM1 or ORAI1 are responsible for a cluster of ultra-rare syndromes characterized by motor disturbances and platelet dysfunction. The prevalence of these disorders is at present unknown. In this study, we describe the generation and characterization of a knock-in mouse model (KISTIM1) that bears a clinically relevant mutation located in one of the two calcium-sensing EF-hand motifs of STIM1. The mouse colony is viable and fertile. Myotubes from these mice show an increased store-operated Ca entry, as predicted. This most likely causes the dystrophic muscle phenotype observed, which worsens with age. Such histological features are not accompanied by a significant increase in creatine kinase. However, animals have significantly worse performance in rotarod and treadmill tests, showing increased susceptibility to fatigue, in analogy to the human disease. The mice also show increased bleeding time and thrombocytopenia, as well as an unexpected defect in the myeloid lineage and in natural killer cells. The present model, together with recently described models bearing the R304W mutation (located on the coiled-coil domain in the cytosolic side of STIM1), represents an ideal platform to characterize the disorder and test therapeutic strategies for patients with STIM1 mutations, currently without therapeutic solutions.This article has an associated First Person interview with Celia Cordero-Sanchez, co-first author of the paper.
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http://dx.doi.org/10.1242/dmm.041111DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6906633PMC
December 2019

SPARC Is a New Myeloid-Derived Suppressor Cell Marker Licensing Suppressive Activities.

Front Immunol 2019 20;10:1369. Epub 2019 Jun 20.

Molecular Immunology Unit, Department of Research, Fondazione IRCCS Istituto Nazionale dei Tumori di Milano, Milan, Italy.

Myeloid-derived suppressor cells (MDSC) are well-known key negative regulators of the immune response during tumor growth, however scattered is the knowledge of their capacity to influence and adapt to the different tumor microenvironments and of the markers that identify those capacities. Here we show that the secreted protein acidic and rich in cysteine (SPARC) identifies in both human and mouse MDSC with immune suppressive capacity and pro-tumoral activities including the induction of epithelial-to-mesenchymal transition (EMT) and angiogenesis. In mice the genetic deletion of SPARC reduced MDSC immune suppression and reverted EMT. c MDSC were less suppressive overall and the granulocytic fraction was more prone to extrude neutrophil extracellular traps (NET). Surprisingly, arginase-I and NOS2, whose expression can be controlled by STAT3, were not down-regulated in c MDSC, although less suppressive than wild type (WT) counterpart. Flow cytometry analysis showed equal phosphorylation of STAT3 but reduced ROS production that was associated with reduced nuclear translocation of the NF-kB p50 subunit in c than WT MDSC. The limited p50 in nuclei reduce the formation of the immunosuppressive p50:p50 homodimers in favor of the p65:p50 inflammatory heterodimers. Supporting this hypothesis, the production of TNF by c MDSC was significantly higher than by WT MDSC. Although associated with tumor-induced chronic inflammation, TNF, if produced at high doses, becomes a key factor in mediating tumor rejection. Therefore, it is foreseeable that an unbalance in TNF production could skew MDSC toward an inflammatory, anti-tumor phenotype. Notably, TNF is also required for inflammation-driven NETosis. The high level of TNF in c MDSC might explain their increased spontaneous NET formation as that we detected both and , in association with signs of endothelial damage. We propose SPARC as a new potential marker of MDSC, in both human and mouse, with the additional feature of controlling MDSC suppressive activity while preventing an excessive inflammatory state through the control of NF-kB signaling pathway.
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http://dx.doi.org/10.3389/fimmu.2019.01369DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6596449PMC
October 2020

Immune Checkpoint Ligand Reverse Signaling: Looking Back to Go Forward in Cancer Therapy.

Cancers (Basel) 2019 May 4;11(5). Epub 2019 May 4.

Molecular Immunology Unit, Research Department, Fondazione IRCCS Istituto Nazionale dei Tumori, 20133 Milan, Italy.

The so-called immune checkpoints are pathways that regulate the timing and intensity of the immune response to avoid an excessive reaction and to protect the host from autoimmunity. Immune checkpoint inhibitors (ICIs) are designed to target the negative regulatory pathways of T cells, and they have been shown to restore anti-tumor immune functions and achieve considerable clinical results. Indeed, several clinical trials have reported durable clinical response in different tumor types, such as melanoma, renal cell carcinoma (RCC) and non-small cell lung cancer (NSCLC). Nonetheless, after the initial enthusiasm, it is now evident that the majority of patients do not benefit from ICIs, due to innate or acquired tumor resistance. It is therefore mandatory to find ways to identify those patients who will respond and to find ways to induce response in those who at present do not benefit from ICIs. In this regard, the expression of programmed death ligand 1 (PD-L1) on neoplastic cells was the first, and most obvious, biomarker exploited to predict the activity of anti-programmed death 1 (PD-1) and/or anti-PD-L1 antibodies. As expected, a correlation was confirmed between the levels of PD-L1 and the efficacy of anti-PD-1 therapy in melanoma, NSCLC and RCC. However, further results from clinical trials showed that some patients display a clinical response regardless of tumor cell PD-L1 expression levels, while others do not benefit from ICI treatment despite the expression of PD-L1 on neoplastic elements. These findings strongly support the notion that other factors may be relevant for the efficacy of ICI-based treatment regimens. Furthermore, although the current dogma indicates that the PD-1/PD-L1 axis exerts its regulatory effects via the signal transduced in PD-1-expressing T cells, recent evidence suggests that a reverse signaling may also exist downstream of PD-L1 in both tumor and immune cells. The reverse signaling of PD-L1, but also of other immune checkpoints, might contribute to the pro-tumoral/immune suppressive environment associated with tumor development and progression. Clarifying this aspect could facilitate the prediction of patients' clinical outcomes, which are so far unpredictable and result in response, resistance or even hyper-progressive disease in some cases.
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http://dx.doi.org/10.3390/cancers11050624DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6563035PMC
May 2019

DNA threads released by activated CD4 T lymphocytes provide autocrine costimulation.

Proc Natl Acad Sci U S A 2019 04 15;116(18):8985-8994. Epub 2019 Apr 15.

Department of Research, Molecular Immunology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, 20133 Milan, Italy.

The extrusion of DNA traps contributes to a key mechanism in which innate immune cells clear pathogens or induce sterile inflammation. Here we provide evidence that CD4 T cells, a critical regulator of adaptive immunity, release extracellular threads of DNA on activation. These DNA extrusions convey autocrine costimulatory signals to T lymphocytes and can be detected in lymph nodes isolated during the priming phase of experimental autoimmune encephalomyelitis (EAE), a CD4 T cell-driven mouse model of multiple sclerosis. Pharmacologic inhibition of mitochondrial reactive oxygen species (mtROS) abolishes the extrusion of DNA by CD4 T cells, reducing cytokine production in vitro and T cell priming against myelin in vivo. Moreover, mtROS blockade during established EAE markedly ameliorates disease severity, dampening autoimmune inflammation of the central nervous system. Taken together, these experimental results elucidate a mechanism of intrinsic immune costimulation mediated by DNA threads released by activated T helper cells, and identify a potential therapeutic target for such disorders as multiple sclerosis, neuromyelitis optica, and CD4 T cell-mediated disorders.
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http://dx.doi.org/10.1073/pnas.1822013116DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6500139PMC
April 2019

Nicotinamide Phosphoribosyltransferase Acts as a Metabolic Gate for Mobilization of Myeloid-Derived Suppressor Cells.

Cancer Res 2019 04 18;79(8):1938-1951. Epub 2019 Feb 18.

Department of Pharmaceutical Sciences, University of Eastern Piedmont, Novara, Italy.

Cancer induces alteration of hematopoiesis to fuel disease progression. We report that in tumor-bearing mice the macrophage colony-stimulating factor elevates the myeloid cell levels of nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme in the NAD salvage pathway, which acts as negative regulator of the CXCR4 retention axis of hematopoietic cells in the bone marrow. NAMPT inhibits CXCR4 through a NAD/Sirtuin 1-mediated inactivation of HIF1α-driven gene transcription, leading to mobilization of immature myeloid-derived suppressor cells (MDSC) and enhancing their production of suppressive nitric oxide. Pharmacologic inhibition or myeloid-specific ablation of NAMPT prevented MDSC mobilization, reactivated specific antitumor immunity, and enhanced the antitumor activity of immune checkpoint inhibitors. Our findings identify NAMPT as a metabolic gate of MDSC precursor function, providing new opportunities to reverse tumor immunosuppression and to restore clinical efficacy of immunotherapy in patients with cancer. SIGNIFICANCE: These findings identify NAMPT as a metabolic gate of MDSC precursor function, providing new opportunities to reverse tumor immunosuppression and to restore clinical efficacy of immunotherapy in cancer patients.
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http://dx.doi.org/10.1158/0008-5472.CAN-18-1544DOI Listing
April 2019

WNT signaling modulates PD-L1 expression in the stem cell compartment of triple-negative breast cancer.

Oncogene 2019 05 31;38(21):4047-4060. Epub 2019 Jan 31.

Molecular Targeting Unit, Department of Research, Fondazione IRCCS Istituto Nazionale dei Tumori di Milano, Milan, Italy.

Triple-negative breast cancers (TNBCs) are characterized by a poor prognosis and lack of targeted treatments, and thus, new therapeutic strategies are urgently needed. Inhibitors against programmed death-1 (PD-1)/PD-1 ligand (PD-L1) have shown significant efficacy in various solid cancers, but their activity against TNBCs remains limited. Here, we report that human TNBCs molecularly stratified for high levels of PD-L1 (PD-L1) showed significantly enriched expression of immune and cancer stemness pathways compared with those with low PD-L1 expression (PD-L1). In addition, the PD-L1 cases were significantly associated with a high stemness score (SS) signature. TNBC cell lines gated for aldehyde dehydrogenase (ALDH) and CD44 stemness markers exhibited increased levels of PD-L1 versus their ALDH-negative and CD44 counterparts, and PD-L1 cells generated significantly more mammospheres than PD-L1 cells. Murine mammary SCA-1-positive tumor cells with PD-L1 expression generated tumors in vivo with higher efficacy than PD-L1 cells. Furthermore, treatment of TNBC cells with selective WNT inhibitors or activators downregulated or upregulated PD-L1 expression, respectively, implying a functional cross-talk between WNT activity and PD-L1 expression. Remarkably, human TNBC samples contained tumor elements co-expressing PD-L1 with ALDH1A1 and/or CD44v6. Additionally, both PD-L1-/SCA1-positive and ALDH1A1-positive tumor elements were found in close contact with CD3-, and PD-1-positive T cells in murine and human tumor samples. Overall, our study suggests that PD-L1-positive tumor elements with a stemness phenotype may participate in the complex dynamics of TNBC-related immune evasion, which might be targeted through WNT signaling inhibition.
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http://dx.doi.org/10.1038/s41388-019-0700-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6755989PMC
May 2019

The P2X7 receptor modulates immune cells infiltration, ectonucleotidases expression and extracellular ATP levels in the tumor microenvironment.

Oncogene 2019 05 17;38(19):3636-3650. Epub 2019 Jan 17.

Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Via Luigi Borsari, 46, 44121, Ferrara, Italy.

In the tumor microenvironment (TME) ATP and its receptor P2X7 exert a pivotal influence on cancer growth and tumor-host interactions. Here we analyzed the different effect of P2X7 genetic deficiency versus its antagonism on response against P2X7-expressing implanted tumors. We focused on immune cell expression of ATP degrading enzymes CD39 and CD73 and in vivo measured TME's ATP. The immune infiltrate of tumors growing in P2X7 null mice shows a decrease in CD8 cells and an increased number of Tregs, overexpressing the fitness markers OX40, PD-1, and CD73. A similar Treg phenotype is also present in the spleen of tumor-bearing P2X7 null mice and it is paralleled by a decrease in proinflammatory cytokines and an increase in TGF-β. Differently, systemic administration of the P2X7 blocker A740003 in wild-type mice left unaltered the number of tumor-infiltrating CD8 and Treg lymphocytes but increased CD4 effector cells and decreased their expression of CD39 and CD73. P2X7 blockade did not affect spleen immune cell composition or ectonucleotidase expression but increased circulating INF-γ. Augmented CD73 in P2X7 null mice was mirrored by a decrease in TME ATP concentration and nucleotide reduced secretion from immune cells. On the contrary, TME ATP levels remained unaltered upon P2X7 antagonism, owing to release of ATP from cancerous cells and diminished ectonucleotidase expression by CD4 and dendritic cells. These data point at P2X7 receptor as a key determinant of TME composition due to its combined action on immune cell infiltrate, ectonucleotidases, and ATP release.
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http://dx.doi.org/10.1038/s41388-019-0684-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6756114PMC
May 2019

Antibody-Fc/FcR Interaction on Macrophages as a Mechanism for Hyperprogressive Disease in Non-small Cell Lung Cancer Subsequent to PD-1/PD-L1 Blockade.

Clin Cancer Res 2019 02 11;25(3):989-999. Epub 2018 Sep 11.

Medical Oncology Department 1, Fondazione IRCCS - Istituto Nazionale dei Tumori, Milan, Italy.

Purpose: Hyperprogression (HP), a paradoxical boost in tumor growth, was described in a subset of patients treated with immune checkpoint inhibitors (ICI). Neither clinicopathologic features nor biological mechanisms associated with HP have been identified.

Experimental Design: Among 187 patients with non-small cell lung cancer (NSCLC) treated with ICI at our institute, cases with HP were identified according to clinical and radiologic criteria. Baseline histologic samples from patients treated with ICI were evaluated by IHC for myeloid and lymphoid markers. T-cell-deficient mice, injected with human lung cancer cells and patient-derived xenografts (PDX) belonging to specific mutational subsets, were assessed for tumor growth after treatment with antibodies against mouse and human programmed death receptor-1 (PD-1). The immune microenvironment was evaluated by flow cytometry and IHC.

Results: Among 187 patients, 152 were evaluable for clinical response. We identified four categories: 32 cases were defined as responders (21%), 42 patients with stable disease (27.7%), 39 cases were defined as progressors (25.7%), and 39 patients with HP (25.7%). Pretreatment tissue samples from all patients with HP showed tumor infiltration by M2-like CD163CD33PD-L1 clustered epithelioid macrophages. Enrichment by tumor-associated macrophages (TAM) was observed, even in tumor nodules from immunodeficient mice injected with human lung cancer cells and with PDXs. In these models, tumor growth was enhanced by treatment with anti-PD-1 but not anti-PD-1 F(ab) fragments.

Conclusions: These results suggest a crucial role of TAM reprogramming, upon Fc receptor engagement by ICI, eventually inducing HP and provide clues on a distinctive immunophenotype potentially able to predict HP..
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http://dx.doi.org/10.1158/1078-0432.CCR-18-1390DOI Listing
February 2019

Cross-Talk between Myeloid-Derived Suppressor Cells and Mast Cells Mediates Tumor-Specific Immunosuppression in Prostate Cancer.

Cancer Immunol Res 2018 05 9;6(5):552-565. Epub 2018 Mar 9.

Molecular Immunology Unit, Department of Research, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.

Immunotherapy, including the use of checkpoint inhibitors, is a potent therapeutic approach for some cancers, but has limited success with prostate tumors, in which immune suppression is instigated by the tumor. The immunosuppressive capacity of mast cells, which promote adenocarcinoma development in the prostate, prompted our investigation on whether mast cells promote tolerance to SV40 Large-T antigen, the transforming oncogene in transgenic adenocarcinoma of the mouse prostate (TRAMP) mice. The incidence of adenocarcinoma was reduced in the offspring of a cross between TRAMP mice and mast cell-deficient Kit mice. TRAMP mice are tolerant to the SV40 Large T antigen, which is otherwise immunogenic in normal syngeneic B6 mice. Genetic ablation of mast cells in TRAMP mice restored their ability to mount a tumor-specific cytotoxic T-cell response. In Kit-TRAMP mice, the restored T-cell immunity correlated with the reduced activity of polymorphonuclear myeloid-derived suppressor cells (PMN-MDSC), along with their reduced expression of , , and Having found that CD40L-expressing mast cells can interact with CD40-expressing PMN-MDSC, we then determined that only Kit-TRAMP mice reconstituted with mast cells expressing CD40L could restore PMN-MDSCs suppressive functions, T-cell unresponsiveness and adenocarcinoma development. Thus, mast cells have an immunoregulatory effect on PMN-MDSCs activity through CD40L-CD40 interaction, favoring immunosuppression and tumor onset. In prostate cancer patients, analyses correlated poor clinical outcomes with high expression of genes related to mast cells and PMN-MDSCs. .
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http://dx.doi.org/10.1158/2326-6066.CIR-17-0385DOI Listing
May 2018

Microenvironmental regulation of the IL-23R/IL-23 axis overrides chronic lymphocytic leukemia indolence.

Sci Transl Med 2018 02;10(428)

Hematology Unit, Department of Onco-Hematology, Azienda Ospedaliera (AO) of Cosenza, 87100 Cosenza, Italy.

Although the progression of chronic lymphocytic leukemia (CLL) requires the cooperation of the microenvironment, the exact cellular and molecular mechanisms involved are still unclear. We investigated the interleukin (IL)-23 receptor (IL-23R)/IL-23 axis and found that circulating cells from early-stage CLL patients with shorter time-to-treatment, but not of those with a more benign course, expressed a defective form of the IL-23R complex lacking the IL-12Rβ1 chain. However, cells from both patient groups expressed the complete IL-23R complex in tissue infiltrates and could be induced to express the IL-12Rβ1 chain when cocultured with activated T cells or CD40L cells. CLL cells activated in vitro in this context produced IL-23, a finding that, together with the presence of IL-23 in CLL lymphoid tissues, suggests the existence of an autocrine/paracrine loop inducing CLL cell proliferation. Interference with the IL-23R/IL-23 axis using an anti-IL-23p19 antibody proved effective in controlling disease onset and expansion in xenografted mice, suggesting potential therapeutic strategies.
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http://dx.doi.org/10.1126/scitranslmed.aal1571DOI Listing
February 2018

ATP Release from Chemotherapy-Treated Dying Leukemia Cells Elicits an Immune Suppressive Effect by Increasing Regulatory T Cells and Tolerogenic Dendritic Cells.

Front Immunol 2017 22;8:1918. Epub 2017 Dec 22.

Department of Experimental, Diagnostic and Specialty Medicine, Institute of Hematology L. and A. Seràgnoli, S. Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy.

Chemotherapy-induced immunogenic cell death can favor dendritic cell (DC) cross-priming of tumor-associated antigens for T cell activation thanks to the release of damage-associated molecular patterns, including ATP. Here, we tested the hypothesis that in acute myeloid leukemia (AML), ATP release, along with its well-known immune stimulatory effect, may also contribute to the generation of an immune suppressive microenvironment. In a cohort of AML patients, undergoing combined daunorubicin and cytarabine chemotherapy, a population of T regulatory cells (Tregs) with suppressive phenotype, expressing the immune checkpoint programmed cell death protein 1 (PD-1), was significantly increased. Moving from these results, initial data showed that daunorubicin was more effective than cytarabine in modulating DC function toward Tregs induction and such difference was correlated with the higher capacity of daunorubicin to induce ATP release from treated AML cells. DCs cultured with daunorubicin-treated AML cells upregulated indoleamine 2,3-dioxygenase 1 (IDO1), which induced anti-leukemia Tregs. These data were confirmed as daunorubicin-treated mice show an increase in extracellular ATP levels with increased number of Tregs, expressing PD-1 and IDO1CD39 DCs. Notably, daunorubicin failed to induce Tregs and tolerogenic DCs in mice lacking the ATP receptor P2X7. Our data indicate that ATP release from chemotherapy-treated dying cells contributes to create an immune suppressive microenvironment in AML.
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http://dx.doi.org/10.3389/fimmu.2017.01918DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5744438PMC
December 2017

Antibody-mediated blockade of JMJD6 interaction with collagen I exerts antifibrotic and antimetastatic activities.

FASEB J 2017 12 8;31(12):5356-5370. Epub 2017 Aug 8.

Molecular Immunology Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Nazionale dei Tumori, Milan, Italy;

JMJD6 is known to localize in the nucleus, exerting histone arginine demethylase and lysyl hydroxylase activities. A novel localization of JMJD6 in the extracellular matrix, resulting from its secretion as a soluble protein, was unveiled by a new anti-JMJD6 mAb called P4E11, which was developed to identify new targets in the stroma. Recombinant JMJD6 binds with collagen type I (Coll-I), and distinct JMJD6 peptides interfere with collagen fibrillogenesis, collagen-fibronectin interaction, and adhesion of human tumor cells to the collagen substrate. P4E11 and collagen binding to JMJD6 are mutually exclusive because the amino acid sequences of JMJD6 necessary for the interaction with Coll-I are part of the conformational epitope recognized by P4E11. In mice injected with mouse 4T1 breast carcinoma cells, treatment with P4E11 reduced fibrosis at the primary tumor and prevented lung metastases. Reduction of fibrosis has also been documented in human breast and ovarian tumors (MDA-MB-231 and IGROV1, respectively) xenotransplanted into immunodeficient mice treated with P4E11. In summary, this study uncovers a new localization and function for JMJD6 that is most likely independent from its canonical enzymatic activities, and demonstrates that JMJD6 can functionally interact with Coll-I. P4E11 mAb, inhibiting JMJD6/Coll-I interaction, represents a new opportunity to target fibrotic and tumor diseases.-Miotti, S., Gulino, A., Ferri, R., Parenza, M., Chronowska, A., Lecis, D., Sangaletti, S., Tagliabue, E., Tripodo, C., Colombo, M. P. Antibody-mediated blockade of JMJD6 interaction with collagen I exerts antifibrotic and antimetastatic activities.
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http://dx.doi.org/10.1096/fj.201700377RDOI Listing
December 2017

The good and bad of targeting cancer-associated extracellular matrix.

Curr Opin Pharmacol 2017 08 19;35:75-82. Epub 2017 Jul 19.

Molecular Immunology Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milano, Italy. Electronic address:

The maintenance of tissue homeostasis requires extracellular matrix (ECM) remodeling. Immune cells actively participate in regenerating damaged tissues contributing to ECM deposition and shaping. Dysregulated ECM deposition characterizes fibrotic diseases and cancer stromatogenesis, where a chronic inflammatory state sustains the ECM increase. In cancer, the ECM fosters several steps of tumor progression, providing pro-survival and proliferative signals, promoting tumor cell dissemination via collagen fibers or acting as a barrier to impede drug diffusion. Interfering with processes leading to chronic ECM deposition, as occurring in cancer, might allow the simultaneous targeting of both primary tumors and metastatic lesions. However, a note of caution comes from data showing that defective ECM deposition is associated with an exacerbated inflammatory and autoimmune phenotype and to lymphomagenesis. Immune cells display ITIM-inhibitory receptors recognizing collagens as counter ligands, which negatively regulate the immune response. This is in line with the idea that ECM components can provide homeostatic signals to immune cells to regulate and prevent unwanted activation, a concept particularly relevant in cancer where these mechanisms could be in place to keep infiltrating immune cells in a suppressive pro-tumoral state. In this context, the pharmacological targeting of myeloid cells, for which both direct and indirect roles in ECM deposition have been shown, can be a relevant option to this purpose.
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http://dx.doi.org/10.1016/j.coph.2017.06.003DOI Listing
August 2017

Trabectedin Overrides Osteosarcoma Differentiative Block and Reprograms the Tumor Immune Environment Enabling Effective Combination with Immune Checkpoint Inhibitors.

Clin Cancer Res 2017 Sep 9;23(17):5149-5161. Epub 2017 Jun 9.

Molecular Immunology Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milano, Italy.

Osteosarcoma, the most common primary bone tumor, is characterized by an aggressive behavior with high tendency to develop lung metastases as well as by multiple genetic aberrations that have hindered the development of targeted therapies. New therapeutic approaches are urgently needed; however, novel combinations with immunotherapies and checkpoint inhibitors require suitable preclinical models with intact immune systems to be properly tested. We have developed immunocompetent osteosarcoma models that grow orthotopically in the bone and spontaneously metastasize to the lungs, mimicking human osteosarcoma. These models have been used to test the efficacy of trabectedin, a chemotherapeutic drug utilized clinically for sarcomas and ovarian cancer. Trabectedin, as monotherapy, significantly inhibited osteosarcoma primary tumor growth and lung metastases by both targeting neoplastic cells and reprogramming the tumor immune microenvironment. Specifically, trabectedin induced a striking differentiation of tumor cells by favoring the recruitment of Runx2, the master genetic regulator of osteoblastogenesis, on the promoter of genes involved in the physiologic process of terminal osteoblast differentiation. Differentiated neoplastic cells, as expected, showed reduced proliferation rate. Concomitantly, trabectedin enhanced the number of tumor-infiltrating T lymphocytes, with local CD8 T cells, however, likely post-activated or exhausted, as suggested by their high expression of the inhibitory checkpoint molecule PD-1. Accordingly, the combination with a PD-1-blocking antibody significantly increased trabectedin efficacy in controlling osteosarcoma progression. These results demonstrate the therapeutic efficacy of trabectedin in osteosarcoma treatment, unveiling its multiple activities and providing a solid rationale for its combination with immune checkpoint inhibitors. .
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http://dx.doi.org/10.1158/1078-0432.CCR-16-3186DOI Listing
September 2017

Persistent Immune Stimulation Exacerbates Genetically Driven Myeloproliferative Disorders via Stromal Remodeling.

Cancer Res 2017 07 23;77(13):3685-3699. Epub 2017 May 23.

Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy.

Systemic immune stimulation has been associated with increased risk of myeloid malignancies, but the pathogenic link is unknown. We demonstrate in animal models that experimental systemic immune activation alters the bone marrow stromal microenvironment, disarranging extracellular matrix (ECM) microarchitecture, with downregulation of secreted protein acidic and rich in cysteine (SPARC) and collagen-I and induction of complement activation. These changes were accompanied by a decrease in Treg frequency and by an increase in activated effector T cells. Under these conditions, hematopoietic precursors harboring nucleophosmin-1 () mutation generated myeloid cells unfit for normal hematopoiesis but prone to immunogenic death, leading to neutrophil extracellular trap (NET) formation. NET fostered the progression of the indolent -driven myeloproliferation toward an exacerbated and proliferative dysplastic phenotype. Enrichment in NET structures was found in the bone marrow of patients with autoimmune disorders and in -mutated acute myelogenous leukemia (AML) patients. Genes involved in NET formation in the animal model were used to design a NET-related inflammatory gene signature for human myeloid malignancies. This signature identified two AML subsets with different genetic complexity and different enrichment in NPM1 mutation and predicted the response to immunomodulatory drugs. Our results indicate that stromal/ECM changes and priming of bone marrow NETosis by systemic inflammatory conditions can complement genetic and epigenetic events towards the development and progression of myeloid malignancy. .
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http://dx.doi.org/10.1158/0008-5472.CAN-17-1098DOI Listing
July 2017

Common extracellular matrix regulation of myeloid cell activity in the bone marrow and tumor microenvironments.

Cancer Immunol Immunother 2017 Aug 13;66(8):1059-1067. Epub 2017 May 13.

Molecular Immunology Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Via Amadeo, 42, 20133, Milan, Italy.

The complex interaction between cells undergoing transformation and the various stromal and immunological cell components of the tumor microenvironment (TME) crucially influences cancer progression and diversification, as well as endowing clinical and prognostic significance. The immunosuppression characterizing the TME depends on the recruitment and activation of different cell types including regulatory T cells, myeloid-derived suppressor cells, and tumor-associated macrophages. Less considered is the non-cellular component of the TME. Here, we focus on the extracellular matrix (ECM) regulatory activities that, within the TME, actively contribute to many aspects of tumor progression, acting on both tumor and immune cells. Particularly, ECM-mediated regulation of tumor-associated immunosuppression occurs through the modulation of myeloid cell expansion, localization, and functional activities. Such regulation is not limited to the TME but occurs also within the bone marrow, wherein matricellular proteins contribute to the maintenance of specialized hematopoietic stem cell niches thereby regulating their homeostasis as well as the generation and expansion of myeloid cells under both physiological and pathological conditions. Highlighting the commonalities among ECM-myeloid cell interactions in bone marrow and TME, in this review we present a picture in which myeloid cells might sense and respond to ECM modifications, providing different ECM-myeloid cell interfaces that may be useful to define prognostic groups and to tailor therapeutic interventions.
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http://dx.doi.org/10.1007/s00262-017-2014-yDOI Listing
August 2017

Matricellular proteins tune myeloid-derived suppressor cell recruitment and function in breast cancer.

J Leukoc Biol 2017 08 1;102(2):287-292. Epub 2017 Feb 1.

Molecular Immunology Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione Instituto di Ricovero e Cura a Carattere Scientifico Istituto Nazionale dei Tumori, Milano, Italy

Solid tumor progression is often associated with the expansion of myeloid-derived suppressor cells (MDSCs), a heterogeneous population of immature myeloid cells that actively foster tumor growth and metastatic dissemination through a plethora of mechanisms, including, but not limited to, their major suppressive activity on the immune response. Indeed, MDSCs may sustain tumor progression by dynamically remodeling the tumor microenvironment through the production of angiogenic factors and metalloproteases, by helping the establishment of a premetastatic niche, and by promoting stemness and epithelial-to-mesenchymal transition (EMT) features in tumor cells. MDSCs are also regulated by a growing list of factors that mainly comprise 2 sets of signals: those responsible for their expansion and recruitment, such as GM-, M-, and G-CSF and other growth factors, and those relevant for the induction of their suppressive activity, which include proinflammatory cytokines and transcription factors. We review here a new class of MDSC regulators-matricellular proteins-with a particular focus on osteopontin (OPN) and secreted acidic cysteine-rich glycoprotein (SPARC), which seem to affect the expansion/recruitment and the immune-suppressive activity of MDSCs. Matricellular proteins function indirectly on MDSCs through the induction of other mediators when produced by tumor cells and cell autonomously when expressed-likely in an intracellular form-directly by MDSCs.
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http://dx.doi.org/10.1189/jlb.3MR1016-447RDOI Listing
August 2017

Mesenchymal Transition of High-Grade Breast Carcinomas Depends on Extracellular Matrix Control of Myeloid Suppressor Cell Activity.

Cell Rep 2016 09;17(1):233-248

Molecular Immunology Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale Tumori, 20133 Milan, Italy. Electronic address:

The extracellular matrix (ECM) contributes to the biological and clinical heterogeneity of breast cancer, and different prognostic groups can be identified according to specific ECM signatures. In high-grade, but not low-grade, tumors, an ECM signature characterized by high SPARC expression (ECM3) identifies tumors with increased epithelial-to-mesenchymal transition (EMT), reduced treatment response, and poor prognosis. To better understand how this ECM3 signature is contributing to tumorigenesis, we expressed SPARC in isogenic cell lines and found that SPARC overexpression in tumor cells reduces their growth rate and induces EMT. SPARC expression also results in the formation of a highly immunosuppressive microenvironment, composed by infiltrating T regulatory cells, mast cells, and myeloid-derived suppressor cells (MDSCs). The ability of SPARC to induce EMT depended on the localization and suppressive function of myeloid cells, and inhibition of the suppressive function MDSCs by administration of aminobisphosphonates could revert EMT, rendering SPARC-overexpressing tumor cells sensitive to Doxil. We conclude that that SPARC is regulating the interplay between MDSCs and the ECM to drive the induction of EMT in tumor cells.
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http://dx.doi.org/10.1016/j.celrep.2016.08.075DOI Listing
September 2016

Genetic deletion of osteopontin in TRAMP mice skews prostate carcinogenesis from adenocarcinoma to aggressive human-like neuroendocrine cancers.

Oncotarget 2016 Jan;7(4):3905-20

Molecular Immunology Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale Tumori, 20133, Milano, Italy.

Osteopontin (OPN) is a secreted glycoprotein, that belongs to the non-structural extracellular matrix (ECM), and its over expression in human prostate cancer has been associated with disease progression, androgen independence and metastatic ability. Nevertheless, the pathophysiology of OPN in prostate tumorigenesis has never been studied. We crossed TRansgenic Adenocarcinoma of the Mouse Prostate (TRAMP) mice with OPN deficient (OPN-/-) mice and followed tumor onset and progression in these double mutants. Ultrasound examination detected the early onset of a rapidly growing, homogeneous and spherical tumor in about 60% of OPN-/- TRAMP mice. Such neoplasms seldom occurred in parental TRAMP mice otherwise prone to adenocarcinomas and were characterized for being androgen receptor negative, highly proliferative and endowed with neuroendocrine (NE) features. Gene expression profiling showed up-regulation of genes involved in tumor progression, cell cycle and neuronal differentiation in OPN-deficient versus wild type TRAMP tumors. Down-regulated genes included key genes of TGFa pathway, including SMAD3 and Filamin, which were confirmed at the protein level. Furthermore, NE genes and particularly those characterizing early prostatic lesions of OPN-deficient mice were found to correlate with those of human prostate NE tumours. These data underscore a novel role of OPN in the early stages of prostate cancer growth, protecting against the development of aggressive NE tumors.
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http://dx.doi.org/10.18632/oncotarget.6678DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4826179PMC
January 2016

RORC1 Regulates Tumor-Promoting "Emergency" Granulo-Monocytopoiesis.

Cancer Cell 2015 Aug;28(2):253-69

Department of Inflammation and Immunology, Humanitas Clinical and Research Center, 20089 Rozzano, Milan, Italy; Department of Pharmaceutical Sciences, Università del Piemonte Orientale "Amedeo Avogadro," Via Bovio 6, 28100 Novara, Italy. Electronic address:

Cancer-driven granulo-monocytopoiesis stimulates expansion of tumor promoting myeloid populations, mostly myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs). We identified subsets of MDSCs and TAMs based on the expression of retinoic-acid-related orphan receptor (RORC1/RORγ) in human and mouse tumor bearers. RORC1 orchestrates myelopoiesis by suppressing negative (Socs3 and Bcl3) and promoting positive (C/EBPβ) regulators of granulopoiesis, as well as the key transcriptional mediators of myeloid progenitor commitment and differentiation to the monocytic/macrophage lineage (IRF8 and PU.1). RORC1 supported tumor-promoting innate immunity by protecting MDSCs from apoptosis, mediating TAM differentiation and M2 polarization, and limiting tumor infiltration by mature neutrophils. Accordingly, ablation of RORC1 in the hematopoietic compartment prevented cancer-driven myelopoiesis, resulting in inhibition of tumor growth and metastasis.
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http://dx.doi.org/10.1016/j.ccell.2015.07.006DOI Listing
August 2015

Mast Cells Infiltrating Inflamed or Transformed Gut Alternatively Sustain Mucosal Healing or Tumor Growth.

Cancer Res 2015 Sep 23;75(18):3760-70. Epub 2015 Jul 23.

Molecular Immunology Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.

Mast cells (MC) are immune cells located next to the intestinal epithelium with regulatory function in maintaining the homeostasis of the mucosal barrier. We have investigated MC activities in colon inflammation and cancer in mice either wild-type (WT) or MC-deficient (Kit(W-sh)) reconstituted or not with bone marrow-derived MCs. Colitis was chemically induced with dextran sodium sulfate (DSS). Tumors were induced by administering azoxymethane (AOM) intraperitoneally before DSS. Following DSS withdrawal, Kit(W-sh) mice showed reduced weight gain and impaired tissue repair compared with their WT littermates or Kit(W-sh) mice reconstituted with bone marrow-derived MCs. MCs were localized in areas of mucosal healing rather than damaged areas where they degraded IL33, an alarmin released by epithelial cells during tissue damage. Kit(W-sh) mice reconstituted with MC deficient for mouse mast cell protease 4 did not restore normal mucosal healing or reduce efficiently inflammation after DSS withdrawal. In contrast with MCs recruited during inflammation-associated wound healing, MCs adjacent to transformed epithelial cells acquired a protumorigenic profile. In AOM- and DSS-treated WT mice, high MC density correlated with high-grade carcinomas. In similarly treated Kit(W-sh) mice, tumors were less extended and displayed lower histologic grade. Our results indicate that the interaction of MCs with epithelial cells is dependent on the inflammatory stage, and on the activation of the tissue repair program. Selective targeting of MCs for prevention or treatment of inflammation-associated colon cancer should be timely pondered to allow tissue repair at premalignant stages or to reduce aggressiveness at the tumor stage.
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http://dx.doi.org/10.1158/0008-5472.CAN-14-3767DOI Listing
September 2015

The ins and outs of osteopontin.

Oncoimmunology 2015 Mar 2;4(3):e978711. Epub 2015 Apr 2.

Molecular Immunology Unit; Department of Experimental Oncology and Molecular Medicine; Fondazione IRCCS Istituto Nazionale Tumori ; Milan, Italy.

The continuous remodeling of progressing tumors demands non-physiologic production of extracellular matrix (ECM) proteins. Among them, osteopontin (OPN) has been largely involved in tumor progression and metastasis. We have recently discovered a new mechanism for OPN in the metastatic spread of mammary carcinoma providing local immunosuppression at the seeding site.
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http://dx.doi.org/10.4161/2162402X.2014.978711DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4404798PMC
March 2015