0000000000486072
AUTHOR
Laura Botti
showing 25 related works from this author
Infiltrating mast cell-mediated stimulation of estrogen receptor activity in breast cancer cells promotes the luminal phenotype
2019
Abstract Tumor growth and development is determined by both cancer cell–autonomous and microenvironmental mechanisms, including the contribution of infiltrating immune cells. Because the role of mast cells (MC) in this process is poorly characterized and even controversial, we investigated their part in breast cancer. Crossing C57BL/6 MMTV-PyMT mice, which spontaneously develop mammary carcinomas, with MC-deficient C57BL/6-KitW-sh/W-sh (Wsh) mice, showed that MCs promote tumor growth and prevent the development of basal CK5-positive areas in favor of a luminal gene program. When cocultured with breast cancer cells in vitro, MCs hindered activation of cMET, a master regulator of the basal pr…
SPARC regulation of PMN clearance protects from pristane induced lupus and rheumatoid arthritis
2020
AbstractOne step along the pathogenesis of Systemic lupus erythematosus (SLE) is associated with polymorphonuclear leukocyte (PMN) death and their ineffective removal by M2-macrophages. The secreted protein acidic and rich in cysteine (SPARC) is a matricellular protein with unexpected immunosuppressive function in M2-macrophages and myeloid cells. To investigate the role of SPARC in autoimmunity, we adopted a pristane–induced model of lupus in mice, which recapitulates clinical manifestations of human SLE. Sparc-/- mice developed earlier and more severe renal disease, lung and liver parenchymal damage than the WT counterpart. Most prominently, Sparc-/- mice had anticipated and severe occurr…
Stromal niche communalities underscore the contribution of the matricellular protein SPARC to B-cell development and lymphoid malignancies
2014
Neoplastic B-cell clones commonly arise within secondary lymphoid organs (SLO). However, during disease progression, lymphomatous cells may also colonize the bone marrow (BM), where they localize within specialized stromal niches, namely the osteoblastic and the vascular niche, according to their germinal center-or extra-follicular-derivation, respectively. We hypothesized the existence of common stromal motifs in BM and SLO B-cell lymphoid niches involved in licensing normal B-cell development as well as in fostering transformed B lymphoid cells. Thus, we tested the expression of prototypical mesenchymal stromal cell (MSC) markers and regulatory matricellular proteins in human BM and SLO u…
Persistent immune stimulation exacerbates genetically driven myeloproliferative disorders via stromal remodeling
2017
Abstract 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 (NPM1) mutation generated myeloid cells unfit for normal …
Intracellular osteopontin protects from autoimmunity-driven lymphoma development inhibiting TLR9-MYD88-STAT3 signaling
2022
Abstract Background Autoimmune disorders, including Systemic Lupus Erythematosus (SLE), are associated with increased incidence of hematological malignancies. The matricellular protein osteopontin (OPN) has been linked to SLE pathogenesis, as SLE patients show increased serum levels of OPN and often polymorphisms in its gene. Although widely studied for its pro-tumorigenic role in different solid tumours, the role of OPN in autoimmunity-driven lymphomagenesis has not been investigated yet. Methods To test the role of OPN in the SLE-associated lymphomagenesis, the SLE-like prone Faslpr/lpr mutation was transferred onto an OPN-deficient background. Spleen from Faslpr/lpr and OPN-/-Faslpr/lpr …
Mesenchymal Transition of High-Grade Breast Carcinomas Depends on Extracellular Matrix Control of Myeloid Suppressor Cell Activity
2016
SummaryThe 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 h…
Intra-tumor heterogeneity of Diffuse Large B-cell Lymphoma involves the induction of diversified stroma-tumor interfaces
2020
ABSTRACTIntra-tumor heterogeneity in lymphoid malignancies is articulated around several fundamentals, encompassing selection of genetic subclonal events and epigenetic regulation of transcriptional programs. Clonally-related neoplastic cell populations are unsteadily subjected to immune editing and metabolic adaptations within different tissue microenvironments. How tissue-intrinsic mesenchymal determinants impact on the diversification of aggressive lymphomas is still unknown. In this study we adopted the established A20 line-based model of Diffuse Large B-cell Lymphoma (DLBCL), to investigate the intra-tumor heterogeneity associated with the infiltration of different tissue microenvironm…
SPARC is a new myeloid-derived suppressor cell marker licensing suppressive activities
2019
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. Sparc−/− MDSC were less suppressive overall and the granu…
Neutrophil extracellular traps arm DC vaccination against NPM-mutant myeloproliferation
2022
Neutrophil extracellular traps (NETs) are web-like chromatin structures composed by dsDNA and histones, decorated with antimicrobial proteins. Their interaction with dendritic cells (DCs) allows DC activation and maturation toward presentation of NET-associated antigens. Differently from other types of cell death that imply protein denaturation, NETosis preserves the proteins localized onto the DNA threads for proper enzymatic activity and conformational status, including immunogenic epitopes. Besides neutrophils, leukemic cells can release extracellular traps displaying leukemia-associated antigens, prototypically mutant nucleophosmin (NPMc+) that upon mutation translocates from nucleolus …
CD40 provides immune privilege to the bone marrow hematopoietic niche
2020
AbstractAllogeneic bone marrow transplantation remains the only therapeutic option for a wide range of hematological malignancies despite the risk of possible adverse, immune-related events, such as infection and acute graft-versus-host disease (aGVHD). aGVHD is characterized by T-cell activation, defective B-cell development and osteoblastic niche destruction in bone marrow (BM) among other issues. Transplant conditioning regimens cause excessive inflammatory cytokines production and impaired regulatory T-cell control of aberrant T-cell activation. Here, we show that mesenchymal cells (MSCs) upregulated CD40 upon irradiation at the expense of mesenchymal markers, and that CD40 endows MSC o…
Intra-tumour heterogeneity of diffuse large B-cell lymphoma involves the induction of diversified stroma-tumour interfaces
2020
Abstract 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 d…
Osteopontin shapes immunosuppression in the metastatic niche.
2014
Abstract The matricellular protein osteopontin (OPN, Spp-1) is widely associated with cancer aggressiveness when produced by tumor cells, but its impact is uncertain when produced by leukocytes in the context of the tumor stroma. In a broad study using Spp1−/− mice along with gene silencing in tumor cells, we obtained evidence of distinct and common activities of OPN when produced by tumor or host cells in a spontaneously metastatic model of breast cancer. Different cellular localization of OPN is associated with its distinct activities, being mainly secreted in tumor cells while intracellular in myeloid cells. OPN produced by tumor cells supported their survival in the blood stream, wherea…
SPARC regulation of PMN clearance protects from pristane-induced lupus and rheumatoid arthritis
2021
Summary The secreted protein acidic and rich in cysteine (SPARC) is a matricellular protein with unexpected immunosuppressive function in myeloid cells. We investigated the role of SPARC in autoimmunity using the pristane-induced model of lupus that, in mice, mimics human systemic lupus erythematosus (SLE). Sparc−/− mice developed earlier and more severe renal disease, multi-organ parenchymal damage, and arthritis than the wild-type counterpart. Sparc+/- heterozygous mice showed an intermediate phenotype suggesting Sparc gene dosage in autoimmune-related events. Mechanistically, reduced Sparc expression in neutrophils blocks their clearance by macrophages, through defective delivery of don'…
Imatinib spares cKit-expressing prostate neuroendocrine tumors, whereas kills seminal vesicle epithelial-stromal tumors by targeting PDGFR-β
2017
Abstract Prostate cancer is a leading cause of cancer-related death in males worldwide. Indeed, advanced and metastatic disease characterized by androgen resistance and often associated with neuroendocrine (NE) differentiation remains incurable. Using the spontaneous prostate cancer TRAMP model, we have shown that mast cells (MCs) support in vivo the growth of prostate adenocarcinoma, whereas their genetic or pharmacologic targeting favors prostate NE cancer arousal. Aiming at simultaneously targeting prostate NE tumor cells and MCs, both expressing the cKit tyrosine kinase receptor, we have tested the therapeutic effect of imatinib in TRAMP mice. Imatinib-treated TRAMP mice experience a pa…
Trabectedin Overrides Osteosarcoma Differentiative Block and Reprograms the Tumor Immune Environment Enabling Effective Combination with Immune Check…
2016
Abstract Purpose: 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. Experimental Design: 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 effica…
CD40 activity on mesenchymal cells negatively regulates OX40L to maintain bone marrow immune homeostasis under stress conditions
2021
BackgroundWithin the bone marrow (BM), mature T cells are maintained under homeostatic conditions to facilitate proper hematopoietic development. This homeostasis depends upon a peculiar elevated frequency of regulatory T cells (Tregs) and immune regulatory activities from BM-mesenchymal stem cells (BM-MSCs). In response to BM transplantation (BMT), the conditioning regimen exposes the BM to a dramatic induction of inflammatory cytokines and causes an unbalanced T-effector (Teff) and Treg ratio. This imbalance negatively impacts hematopoiesis, particularly in regard to B-cell lymphopoiesis that requires an intact cross-talk between BM-MSCs and Tregs. The mechanisms underlying the ability of…
Transcriptional Profiles and Stromal Changes Reveal Bone Marrow Adaptation to Early Breast Cancer in Association with Deregulated Circulating microRN…
2020
Abstract 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…
Additional file 1 of Intracellular osteopontin protects from autoimmunity-driven lymphoma development inhibiting TLR9-MYD88-STAT3 signaling
2023
Additional file 1. Supplementary file 1. Supplementary Material & methods.
Additional file 6 of Intracellular osteopontin protects from autoimmunity-driven lymphoma development inhibiting TLR9-MYD88-STAT3 signaling
2023
Additional file 6: Supplementary Figure S3. Immunohistochemistry staining of OPN IHC for OPN was performed in Fas lpr/lpr and OPN-/-Fas lpr/lpr mice with either no lymphoma or with lymphomatous cells. As expected, no staining is detected in case of OPN-deficient mice.
Additional file 4 of Intracellular osteopontin protects from autoimmunity-driven lymphoma development inhibiting TLR9-MYD88-STAT3 signaling
2023
Additional file 4: Supplementary Figure S1. Evaluation of autoimmunity in Faslpr/lpr and OPN-/-Faslpr/lpr mice. A. Quantification of OPN in sera from Faslpr/lpr mice at 2 (n=8) and 5 months of age (n=7) by ELISA. Sera from BALB/c and OPN-/- mice were tested as controls. Data are expressed as ng/ml and are a pool of 2 experiments (*, P<0.05; Ordinary one way ANOVA). B. Flow cytometry analysis showing the relative number of splenic autoimmune CD3+B220+ T cells in Faslpr/lpr (n=15) and OPN-/-Faslpr/lpr mice (n=18) and at about 5-6 months of age. The graph shows a pool of 3 different experiments (***, P<0.001; Student t test). C. Representative spleen photograph from BALB/c, OPN-/-, Faslp…
Additional file 7 of Intracellular osteopontin protects from autoimmunity-driven lymphoma development inhibiting TLR9-MYD88-STAT3 signaling
2023
Additional file 7: Supplementary Figure S4. Characterization of OPL239 and OPL241 DLBCL cell lines. A. Flow cytometry analysis showing the expression of B220, IgM, IgD and IgA in OPL239 and OPL241 cell lines. B. Hardy’s multiparametric flow cytometry panel illustrating the expression of CD93, CD21/35 and CD23 on OPL239 and OPL241 cell lines. C. Flow cytometry analysis showing the expression of TLR9 on OPL239 and OPL241 cell lines. D. RT-PCR analysis showing Spp1 mRNA level in overexpressing cell variants. E. Western blot for OPN protein expression (in presence or not of BFA, that blocks protein secretion) in parental and IRES-Green-based cell variants. 4T1 mammary cell line was used as posi…
Additional file 5 of Intracellular osteopontin protects from autoimmunity-driven lymphoma development inhibiting TLR9-MYD88-STAT3 signaling
2023
Additional file 5: Supplementary Figure S2. Evaluation of the different spenic B cell subsets. A. Example of Hardy’s gating strategy to discern the different CD93+ immature (Transitional T1, T2, T3) and CD93- mature [follicular B (FOB), marginal zone B (MZB) and CD21/35-CD23-] B cell subsets in the spleen from a BALB/c mouse. B. Flow cytometry analysis based on Hardy’s multiparametric panel illustrating the fraction of splenic CD23+ FOB, CD21/35+ MZB cells, and CD23-CD21/35- cells from the spleens of naive and autoimmune mice. 3 mice per group were used for the experiment. Data are referred to one representative experiment out of 3 (***, P<0.001; Two-way ANOVA) (****, P<0.0001; Two-wa…
Additional file 8 of Intracellular osteopontin protects from autoimmunity-driven lymphoma development inhibiting TLR9-MYD88-STAT3 signaling
2023
Additional file 8: Supplementary Figure S5. Expression of OPN in human GCB- and ABC-DLBCL samples. Immunohistochemistry analysis for OPN was performed on six cases for GCB- and ABC-DLBCLs. Representative images for two cases for each subtype are shown (quantification is shown in Figure 7B). Magnification 20X.
Additional file 2 of Intracellular osteopontin protects from autoimmunity-driven lymphoma development inhibiting TLR9-MYD88-STAT3 signaling
2023
Additional file 2: Supplementary Table S1. Differentially expressed genes between CD19+ cellsfrom OPN-/-Fas lpr/lpr and Faslpr/lpr mice.
Additional file 3 of Intracellular osteopontin protects from autoimmunity-driven lymphoma development inhibiting TLR9-MYD88-STAT3 signaling
2023
Additional file 3: Supplementary Table S2. Differentially expressed genes between CD19+ cellsfrom OPN-/-and OPN+/+ mice.