A Novel Automatic Algorithm to Support Lung Ultrasound Non-Expert Physicians in Interstitial Pneumonia Evaluation: A Single-Center Study

INTRODUCTION

Lung ultrasound (LUS) is widely used in clinical practice for identifying interstitial lung diseases (ILDs) and assessing their progression. Although high-resolution computed tomography (HRCT) remains the gold standard for evaluating the severity of ILDs, LUS can be performed as a screening method or as a follow-up tool post-HRCT. Minimum training is needed to better identify typical lesions, and the integration of innovative artificial intelligence (AI) automatic algorithms may enhance diagnostic efficiency.

AIM

This study aims to assess the effectiveness of a novel AI algorithm in automatic ILD recognition and scoring in comparison to an expert LUS sonographer. The "SensUS Lung" device, equipped with an automatic algorithm, was employed for the automatic recognition of the typical ILD patterns and to calculate an index grading of the interstitial involvement.

METHODS

We selected 33 Caucasian patients in follow-up for ILDs exhibiting typical HRCT patterns (honeycombing, ground glass, fibrosis). An expert physician evaluated all patients with LUS on twelve segments (six per side). Next, blinded to the previous evaluation, an untrained operator, a non-expert in LUS, performed the exam with the SensUS device equipped with the automatic algorithm ("SensUS Lung") using the same protocol. Pulmonary functional tests (PFT) and DLCO were conducted for all patients, categorizing them as having reduced or preserved DLCO. The SensUS device indicated different grades of interstitial involvement named Lung Staging that were scored from 0 (absent) to 4 (peak), which was compared to the Lung Ultrasound Score (LUS score) by dividing it by the number of segments evaluated. Statistical analyses were done with Wilcoxon tests for paired values or Mann-Whitney for unpaired samples, and correlations were performed using Spearman analysis; p < 0.05 was considered significant.

RESULTS

Lung Staging was non-inferior to LUS score in identifying the risk of ILDs (median SensUS 1 [0-2] vs. LUS 0.67 [0.25-1.54]; p = 0.84). Furthermore, the grade of interstitial pulmonary involvement detected with the SensUS device is directly related to the LUS score (r = 0.607, p = 0.002). Lung Staging values were inversely correlated with forced expiratory volume at first second (FEV1%, r = -0.40, p = 0.027), forced vital capacity (FVC%, r = -0.39, p = 0.03) and forced expiratory flow (FEF) at 25th percentile (FEF25%, r = -0.39, p = 0.02) while results directly correlated with FEF25-75% (r = 0.45, p = 0.04) and FEF75% (r = 0.43, p = 0.01). Finally, in patients with reduced DLCO, the Lung Staging was significantly higher, overlapping the LUS (reduced median 1 [1-2] vs. preserved 0 [0-1], p = 0.001), and overlapping the LUS (reduced median 18 [4-20] vs. preserved 5.5 [2-9], p = 0.035).

CONCLUSIONS

Our data suggest that the considered AI automatic algorithm may assist non-expert physicians in LUS, resulting in non-inferior-to-expert LUS despite a tendency to overestimate ILD lesions. Therefore, the AI algorithm has the potential to support physicians, particularly non-expert LUS sonographers, in daily clinical practice to monitor patients with ILDs. The adopted device is user-friendly, offering a fully automatic real-time analysis. However, it needs proper training in basic skills.

The Complexity of the Tumor Microenvironment in Hepatocellular Carcinoma and Emerging Therapeutic Developments

This review explores various aspects of the HCC TME, including both cellular and non-cellular components, to elucidate their roles in tumor development and progression. Specifically, it highlights the significance of cancer-associated fibroblasts (CAFs) and their contributions to tumor progression, angiogenesis, immune suppression, and therapeutic resistance. Moreover, this review emphasizes the role of immune cells, such as tumor-associated macrophages (TAMs), myeloid-derived suppressor cells (MDSCs), and regulatory T-cells (Tregs), in shaping the immunosuppressive microenvironment that promotes tumor growth and immune evasion. Furthermore, we also focused only on the non-cellular components of the HCC TME, including the extracellular matrix (ECM) and the role of hypoxia-induced angiogenesis. Alterations in the composition of ECM and stiffness have been implicated in tumor invasion and metastasis, while hypoxia-driven angiogenesis promotes tumor growth and metastatic spread. The molecular mechanisms underlying these processes, including the activation of hypoxia-inducible factors (HIFs) and vascular endothelial growth factor (VEGF) signaling, are also discussed. In addition to elucidating the complex TME of HCC, this review focuses on emerging therapeutic strategies that target the TME. It highlights the potential of second-line treatments, such as regorafenib, cabozantinib, and ramucirumab, in improving overall survival for advanced HCC patients who have progressed on or were intolerant to first-line therapy. Furthermore, this review explores the implications of the Barcelona Clinic Liver Cancer (BCLC) staging and classification system in guiding HCC management decisions. The BCLC system, which incorporates tumor stage, liver function, and performance status, provides a framework for treatment stratification and prognosis prediction in HCC patients. The insights gained from this review contribute to the development of novel therapeutic interventions and personalized treatment approaches for HCC patients, ultimately improving clinical outcomes in this challenging disease.

Changes in Lipids in Granulomatosis with Polyangiitis Relates to Glucocorticoids and History of Hypertension

Granulomatosis with polyangiitis (GPA) is an ANCA-associated small-vessel vasculitis. Vessel wall inflammation induces multiple vascular damages, leading to accelerated atherosclerosis. Metabolic profile and cardiovascular risk are somewhat understood in GPA patients. Cardiovascular atherosclerotic disease (ASCVD) may represent a risk for outcomes. Our purpose is to evaluate ASCVD risk in GPA patients. Thirty-six patients received GPA diagnosis (T0) and were evaluated after 1 (T1) and 2 (T2) years follow-up. All patients were treated with high-dose glucocorticoid, one-year tapered, along with immunosuppressants. Total cholesterol significantly increased in T1 vs. T0 and T2. LDL exhibited the same trend, while triglycerides increased in both T1 and T2 vs. T0. No difference was found in HDL. A significant hsCRP decrease was detected at T1 and T2 vs. T0, but not between T2 and T1. Moreover, we found a significant reduction in ESR at T2 compared with T1 and T0 and at T1 compared to T0. Hypertensive patients presented a pronounced increase in lipids, while inflammation reduced slowly compared to normotensives. Our data suggest that the increase in cholesterol and LDL in T1 is a consequence of glucocorticoids. These data can be useful in the evaluation of both CV diseases and lipid metabolism, which are closely related to vessel inflammation.

STAT1 overexpression triggers aplastic anemia: a pilot study unravelling novel pathogenetic insights in bone marrow failure

We identified STAT1 gain of function (GOF) in a 32-year-old female with pallor, weakness, cough, and dyspnea admitted to our Division of Medicine. She had severe oral ulcers (OU), type 1 diabetes (T1DM), and pancytopenia. Bone marrow (BM) biopsy showed the absence of erythroid precursors. Peripheral blood parameters such as neutrophils < 500/mL, reticulocytes < 2%, and BM hypo-cellularity allowed to diagnose severe aplastic anemia. A heterozygous variant (p.520T>C, p.Cys174Arg) of STAT1 was uncovered. Thus, p.Cys174Arg mutation was investigated as potentially responsible for the patient's inborn immunity error and aplastic anemia. Although STAT1 GOF is rare, aplastic anemia is a more common condition; therefore, we explored STAT1 functional role in the pathobiology of BM failure. Interestingly, in a cohort of six patients with idiopathic aplastic anemia, enhanced phospho-STAT1 levels were observed on BM immunostaining. Next, the most remarkable features associated with STAT1 signaling dysregulation were examined: in both pure red cell aplasia and aplastic anemia, CD8+ T cell genetic variants and mutations display enhanced signaling activities related to the JAK-STAT pathway. Inborn errors of immunity may represent a paradigmatic condition to unravel crucial pathobiological mechanisms shared by common pathological conditions. Findings from our case-based approach and the phenotype correspondence to idiopathic aplastic anemia cases prompt further statistically powered prospective studies aiming to elucidate the exact role and theragnostic window for JAK/STAT targeting in this clinical context. Nonetheless, we demonstrate how a comprehensive study of patients with primary immunodeficiencies can lead to pathophysiologic insights and potential therapeutic approaches within a broader spectrum of aplastic anemia cases.

Immune disturbance leads to pulmonary embolism in COVID-19 more than classical risk factors: a clinical and histological study

COVID-19 induces endotheliitis and one of the main complications is enhanced coagulation. The incidence of pulmonary embolism (PE) in COVID-19 (CPE) has increased and clinical features for a rigorous analysis still need to be determined. Thus, we evaluated the clinical characteristics in CPE and the immune infiltration that occurred. Between January 1 and December 31, 2021, 38 patients were affected by CPE (9 ICU, 19 males/19 females, 70.18 ± 11.24 years) out of 459 COVID-19 cases. Controls were subjects who were evaluated for PE between January 1 2015, and December 31, 2019 (92 patients, 9 ICU, 48 males/45 females, 69.55 ± 16.59 years). All patients underwent complete physical examination, pulmonary computed tomography, laboratory tests, D-dimer, and blood gas analysis. There were no differences in laboratory tests or D-dimer. In patients with CPE, pO2, alveolar-arterial oxygen difference (A-aDO2), oxygen saturation %, and the ratio between arterial partial pressure of oxygen (PaO2) and fraction of inspired oxygen (FiO2), P/F, were significantly increased. There were no differences in PaCO2. Platelet count was inversely correlated to P/F (r = - 0.389, p = 0.02) but directly to A-aDO2 (r = 0.699, p = 0.001) only in patients with CPE. Histology of lung biopsies (7 CPE/7 controls) of patients with CPE showed an increase in CD15+ cells, HMGB1, and extracellular MPO as a marker of NETosis, while no significant differences were found in CD3+, CD4+, CD8+, and intracellular MPO. Overall, data suggest that CPE has a different clinical setting. Reduced oxygen content and saturation described in Patients with CPE should not be considered a trustworthy sign of disease. Increased A-aDO2 may indicate that CPE involves the smallest vessels as compared to classical PE. The significant difference in NETosis may suggest the mechanism related to thrombi formation.

Breaking through Multiple Myeloma: A Paradigm for a Comprehensive Tumor Ecosystem Targeting

Multiple myeloma (MM) is a cancerous condition characterized by the proliferation of plasma cells within the hematopoietic marrow, resulting in multiple osteolytic lesions. MM patients typically experience bone pain, kidney damage, fatigue due to anemia, and infections. Historically, MM was an incurable disease with a life expectancy of around three years after diagnosis. However, over the past two decades, the development of novel therapeutics has significantly improved patient outcomes, including response to treatment, remission duration, quality of life, and overall survival. These advancements include thalidomide and its derivatives, lenalidomide and pomalidomide, which exhibit diverse mechanisms of action against the plasma cell clone. Additionally, proteasome inhibitors such as bortezomib, ixazomib, and carfilzomib disrupt protein degradation, proving specifically toxic to cancerous plasma cells. Recent advancements also involve monoclonal antibodies targeting surface antigens, such as elotuzumab (anti-CS1) and daratumumab (anti-CD38), bispecific t-cell engagers such as teclistamab (anti-BCMA/CD3) and Chimeric antigen receptor T (CAR-T)-based strategies, with a growing focus on drugs that exhibit increasingly targeted action against neoplastic plasma cells and relevant effects on the tumor microenvironment.

Uptake-Dependent and -Independent Effects of Fibroblasts-Derived Extracellular Vesicles on Bone Marrow Endothelial Cells from Patients with Multiple Myeloma: Therapeutic and Clinical Implications

Extracellular vesicles (EVs) have emerged as important players in cell-to-cell communication within the bone marrow (BM) of multiple myeloma (MM) patients, where they mediate several tumor-associated processes. Here, we investigate the contribution of fibroblasts-derived EVs (FBEVs) in supporting BM angiogenesis. We demonstrate that FBEVs' cargo contains several angiogenic cytokines (i.e., VEGF, HGF, and ANG-1) that promote an early over-angiogenic effect independent from EVs uptake. Interestingly, co-culture of endothelial cells from MM patients (MMECs) with FBEVs for 1 or 6 h activates the VEGF/VEGFR2, HGF/HGFR, and ANG-1/Tie2 axis, as well as the mTORC2 and Wnt/β-catenin pathways, suggesting that the early over-angiogenic effect is a cytokine-mediated process. FBEVs internalization occurs after longer exposure of MMECs to FBEVs (24 h) and induces a late over-angiogenic effect by increasing MMECs migration, chemotaxis, metalloproteases release, and capillarogenesis. FBEVs uptake activates mTORC1, MAPK, SRC, and STAT pathways that promote the release of pro-angiogenic cytokines, further supporting the pro-angiogenic milieu. Overall, our results demonstrate that FBEVs foster MM angiogenesis through dual time-related uptake-independent and uptake-dependent mechanisms that activate different intracellular pathways and transcriptional programs, providing the rationale for designing novel anti-angiogenic strategies.

microRNAs as Biomarkers of Endothelial Dysfunction and Therapeutic Target in the Pathogenesis of Atrial Fibrillation

The pathophysiology of atrial fibrillation (AF) may involve atrial fibrosis/remodeling and dysfunctional endothelial activities. Despite the currently available treatment approaches, the progression of AF, its recurrence rate, and the high mortality risk of related complications underlay the need for more advanced prognostic and therapeutic strategies. There is increasing attention on the molecular mechanisms controlling AF onset and progression points to the complex cell to cell interplay that triggers fibroblasts, immune cells and myofibroblasts, enhancing atrial fibrosis. In this scenario, endothelial cell dysfunction (ED) might play an unexpected but significant role. microRNAs (miRNAs) regulate gene expression at the post-transcriptional level. In the cardiovascular compartment, both free circulating and exosomal miRNAs entail the control of plaque formation, lipid metabolism, inflammation and angiogenesis, cardiomyocyte growth and contractility, and even the maintenance of cardiac rhythm. Abnormal miRNAs levels may indicate the activation state of circulating cells, and thus represent a specific read-out of cardiac tissue changes. Although several unresolved questions still limit their clinical use, the ease of accessibility in biofluids and their prognostic and diagnostic properties make them novel and attractive biomarker candidates in AF. This article summarizes the most recent features of AF associated with miRNAs and relates them to potentially underlying mechanisms.

Visualizing the Interactions Shaping the Imaging of the Microenvironment in Human Cancers

The Visium Spatial Gene Expression Solution (Visium 10×) allows for the mRNA analysis using high throughput sequencing and maps a transcriptional expression pattern in tissue sections using high-resolution microscope imaging in ex-vivo human and mice samples. The workflow surveys spatial global gene expression in tissue sections, exploiting the whole transcriptome profiling and defining the set of transcripts via targeted gene panels. An automated cell type annotation allows a comparison with control tissue samples. This technique delineates cancerous or diseased tissue boundaries and details gene expression gradients in the tissue surrounding the tumor or pathologic nests. Remarkably, the Visium 10× allows for whole transcriptome and targeted analysis without the loss of spatial information. This approach provides gene expression data within the context of tissue architecture, tissue microenvironments, and cell groups. It can be used in association with therapy, anti-angiogenic therapy, and immunotherapy to improve treatment response.

812 FOLATES-RELATED ERYTHROCYTE DIVERSION LEAD TO ATRIAL CARDIOMYOPATHY/FIBRILLATION THROUGH EPCS DYSFUNCTION

Background

Recent advances support the concept that pre-persistent Atrial Fibrillation (AF) and paradoxical embolism do not explain the wholeness of embolic strokes, thus suggesting a broad Atrial Cardiomyopathy (AC). Pathogenic mechanisms underlying AC are still largely unknown. Folate cycle disorders are a yet underrated dysmetabolism. MTHFR-inherited defects could hinder both endothelial and circulating endothelial progenitor cell (EPCs) functioning, therefore providing one-shot explanation to both atrial stasis (increasing atrial fibrosis and generating atrial hypocontractility even in sinus rhythm) and endothelial dysfunction (ED).

Purpose

This study aims to enquire for the hypothesis that: 1) atrial fibrosis (AFib – intended as a relative percentage of low voltage area in the context of left atrial endocavitary voltage mapping) would relate to folate cycle disorders (intended as both: a)MTHFR C677T inherited mutations and b)bone-marrow function disorders, here referring to erythropoiesis diversions) and 2) AF patients would show dysfunctional EPCs.

Methods

We studied 59 consecutive patients admitted to the cardiology Unit of the General Hospital “F.Miulli”, with preserved EF, subjected to AF ablation. AFib was quantified by bipolar peak-to-peak voltage areas (&lt;0,5 mV) with respect to the wholeness of the picked voltage points. Blood count cell was evaluated by a commercial laboratory test. EPCs isolation and characterization were performed by Ficoll-Hypaque gradient and following flow cytometry analysis for cell surface antigens: CD45, CD34, CD133, VEGFR2 and KDR. EPCs functional wound healing assay was performed to determine the number of EPCs migrated to the “wound”, measuring the percentage of relative wound closure compared with matched-controls.

Results

Baseline characteristics did not differ between Sample and Control groups. % of Afib significantly differs between C677T MTHFR homozigosis patients (n=15) with respect to non-C&//T MTHFR homozygosis patients (n=44 p &lt; 0,02). Once univariate analysis was performed, subsequent multivariate analysis highlights highest fit once merged RBC, RDW-SD and folates values were inputed: Goodness of fit was proper, modelling good (Low figure - R2=0,39; p=0,0001). Either RBC, RDW-SD and folates coefficient reached significance (p &lt; 0,0001; p &lt; 0,01; p &lt; 0,05 respectively). Number of EPCs significantly differs between AF patients and matched controls (p &lt; 0,001).

Conclusions

Our findings support the hypothesis that genetically determined folates dysmetabolism (MTHFR dysfunction) promotes AFib via a complex cardiac-bone marrow networking involving circulating EPCs and unraveled by erythropoiesis diversions. Such results suggest a pathogenic role of folate cycle disorders in the AC development

Pathways of Angiogenic and Inflammatory Cytokines in Multiple Myeloma: Role in Plasma Cell Clonal Expansion and Drug Resistance

Multiple myeloma (MM) is the second most common hematological malignancy, and despite the introduction of innovative therapies, remains an incurable disease. Identifying early and minimally or non-invasive biomarkers for predicting clinical outcomes and therapeutic responses is an active field of investigation. Malignant plasma cells (PCs) reside in the bone marrow (BM) microenvironment (BMME) which comprises cells (e.g., tumour, immune, stromal cells), components of the extracellular matrix (ECM) and vesicular and non-vesicular (soluble) molecules, all factors that support PCs’ survival and proliferation. The interaction between PCs and BM stromal cells (BMSCs), a hallmark of MM progression, is based not only on intercellular interactions but also on autocrine and paracrine circuits mediated by soluble or vesicular components. In fact, PCs and BMSCs secrete various cytokines, including angiogenic cytokines, essential for the formation of specialized niches called “osteoblastic and vascular niches”, thus supporting neovascularization and bone disease, vital processes that modulate the pathophysiological PCs–BMME interactions, and ultimately promoting disease progression. Here, we aim to discuss the roles of cytokines and growth factors in pathogenetic pathways in MM and as prognostic and predictive biomarkers. We also discuss the potential of targeted drugs that simultaneously block PCs’ proliferation and survival, PCs–BMSCs interactions and BMSCs activity, which may represent the future goal of MM therapy.

Cardiovascular Risk in Patients With Takayasu Arteritis Directly Correlates With Diastolic Dysfunction and Inflammatory Cell Infiltration in the Vessel Wall: A Clinical, ex vivo and in vitro Analysis

Background

Takayasu Arteritis (TAK) increases vascular stiffness and arterial resistance. Atherosclerosis leads to similar changes. We investigated possible differences in cardiovascular remodeling between these diseases and whether the differences are correlated with immune cell expression.

Methods

Patients with active TAK arteritis were compared with age- and sex-matched atherosclerotic patients (Controls). In a subpopulation of TAK patients, Treg/Th17 cells were measured before (T0) and after 18 months (T18) of infliximab treatment. Echocardiogram, supraaortic Doppler ultrasound, and lymphocytogram were performed in all patients. Histological and immunohistochemical changes of the vessel wall were evaluated as well.

Results

TAK patients have increased aortic valve dysfunction and diastolic dysfunction. The degree of dysfunction appears associated with uric acid levels. A significant increase in aortic stiffness was also observed and associated with levels of peripheral T lymphocytes. CD3⁺ CD4⁺ cell infiltrates were detected in the vessel wall samples of TAK patients, whose mean percentage of Tregs was lower than Controls at T0, but increased significantly at T18. Opposite behavior was observed for Th17 cells. Finally, TAK patients were found to have an increased risk of atherosclerotic cardiovascular disease (ASCVD).

Conclusion

Our data suggest that different pathogenic mechanisms underlie vessel damage, including atherosclerosis, in TAK patients compared with Controls. The increased risk of ASCVD in TAK patients correlates directly with the degree of inflammatory cell infiltration in the vessel wall. Infliximab restores the normal frequency of Tregs/Th17 in TAK patients and allows a possible reduction of steroids and immunosuppressants.

Folates dysmetabolism promotes atrial cardiomyopathy/fibrillation through a cardiac-bone marrow networking involving endothelial progenitor cell dysfunction and erythropoiesis diversion

Funding Acknowledgements

Type of funding sources: Private hospital(s). Main funding source(s): dedicated cardiovascular research foud

Background

Recent advances support the concept that pre-persistent Atrial Fibrillation (AF) does not explain the wholeness of embolic strokes, suggesting the recently postulated hypothesis of a broad Atrial Cardiomyopathy (AC). In contrast to its worldwide distribution and its very inclusive definition, pathogenic mechanisms underlying AC are still largely unknown. Folate cycle disorders (FCD) are a yet underrated dysmetabolism only partly explained by methylene tetrahydrofolate reductase (MTHFR)-inherited defects. On a translational basis, FCD could hinder both endothelial and circulating endothelial progenitor cell (EPCs) functioning, therefore providing one-shot explanation to both atrial stasis (increasing atrial fibrosis and generating atrial hypocontractility) and endothelial dysfunction (ED). If such cardiac-bone marrow networking would be verified, a fundamental pathogenic mechanism of AC and subsequent AF would be unraveled.

Purpose

This study aims to enquire for the hypothesis that: 1) atrial fibrosis (AFib) would relate to FCD (intended as both: a)MTHFR C677T inherited mutations and b)bone-marrow function disorders, here referring to erythropoiesis diversions) and 2) AF patients would show dysfunctional EPCs.

Methods

We studied 59 consecutive patients admitted to the Cardiology Unit of the General Hospital "F.Miulli", with preserved EF, subjected to AF ablation. AFib was quantified by relative % of low-voltage (&lt;0,5 mV) bipolar peak-to-peak points, with respect to the wholeness of the endocavitary mapping. Blood count cell was evaluated. MTHFR C677T genotypes were elucidated by RT-PCR. Folate were measured by a commercial laboratory test. EPCs isolation and characterization were performed by Ficoll-Hypaque gradient and flow cytometry analysis for cell surface antigens: CD45, CD34, CD133, VEGFR2 and KDR. EPCs functional wound healing assay was performed.

Results

Baseline characteristics did not differ between Sample and Control groups (Fig. 1 – Left Table). % of Afib significantly differs between C677T MTHFR homozigosis patients (n=15) with respect to non-C677T MTHFR homozygosis patients (n=44) (Fig.1 – Right graph. - p &lt; 0,02). Once univariate analysis was performed, subsequent multivariate analysis highlights highest fit once merged RBC, RDW-SD and folates values were inputed: Goodness of fit was proper, modelling good (Fig.2 – superior graph. - R2=0,39; p=0,0001). Either RBC, RDW-SD and folates coefficient reached significance (p &lt; 0,0001; p &lt; 0,01; p &lt; 0,05 respectively). Number of EPCs significantly differs between AF patients and matched controls (Fig 2 – inferior graph. – p &lt; 0,001).

Conclusions

Our findings support the hypothesis that genetically determined folates dysmetabolism (MTHFR dysfunction) promotes AFib via a complex cardiac-bone marrow networking involving circulating EPCs and unraveled by erythropoiesis diversions. Such results suggest a pathogenic role of folate cycle disorders in the AC development.

The Landscape of lncRNAs in Multiple Myeloma: Implications in the "Hallmarks of Cancer", Clinical Perspectives and Therapeutic Opportunities

Simple Summary

Multiple myeloma (MM) is an aggressive hematological neoplasia caused by the uncontrolled proliferation of aberrant plasmacells. Neoplastic transformation and progression are driven by a number of biological processes, called ‘hallmarks of cancer’, which are regulated by different molecules, including long non-coding RNAs. A deeper understanding of the mechanisms that regulate MM development and progression will help to improve patients stratification and management, and promote the identification of new therapeutic targets.

Abstract

Long non-coding RNAs (lncRNAs) are transcripts longer than 200 nucleotides that are not translated into proteins. Nowadays, lncRNAs are gaining importance as key regulators of gene expression and, consequently, of several biological functions in physiological and pathological conditions, including cancer. Here, we point out the role of lncRNAs in the pathogenesis of multiple myeloma (MM). We focus on their ability to regulate the biological processes identified as “hallmarks of cancer” that enable malignant cell transformation, early tumor onset and progression. The aberrant expression of lncRNAs in MM suggests their potential use as clinical biomarkers for diagnosis, patient stratification, and clinical management. Moreover, they represent ideal candidates for therapeutic targeting.

MicroRNAs as a Potential New Preventive Approach in the Transition from Asymptomatic to Symptomatic Multiple Myeloma Disease

Simple Summary

Multiple myeloma (MM) is the second most common haematologic malignancy, and it remains an incurable disease despite the advances of novel therapies. It is characterised by a multistep process that arises from a pre-malignant asymptomatic status-defined monoclonal gammopathy of undetermined significance (MGUS), evolves to a middle stage named smouldering myeloma phase (SMM), and culminates in the active disease (MM). Identification of early and non-invasive markers of the disease progression is currently an active field of investigation. In this review, we discuss the role and significance of microRNAs (miRNAs) as potential diagnostic biomarkers to predict the clinical transition from MGUS/SMM status to MM.

Abstract

Multiple myeloma (MM) is a hematological malignancy characterised by proliferation of clonal plasma cells (PCs) within the bone marrow (BM). Myelomagenesis is a multi-step process which goes from an asymptomatic phase, defined as monoclonal gammopathy of undetermined significance (MGUS), to a smouldering myeloma (SMM) stage, to a final active MM disease, characterised by hypercalcemia, renal failure, bone lesions anemia, and higher risk of infections. Overall, microRNAs (miRNAs) have shown to significantly impact on MM tumorigenesis, as a result of miRNA-dependent modulation of genes involved in pathways known to be crucial for MM pathogenesis and disease progression. We aim to revise the literature related to the role of miRNAs as potential diagnostic and prognostic biomarkers, thus highlighting their key role as novel players within the field of MM and related premalignant conditions.

Study of cellular toxicity in vitro of two resins for orthodontic use

OBJECTIVE

The objective of this work is to compare cellular toxicity in vitro of two resins for orthodontic use: an auto-polymerizable composite and a photo-polymerizable composite.

MATERIALS AND METHODS

Samples were obtained by joining a couple of steel orthodontic brackets by using auto-polymerizing or photo-polymerizing resin. We used a halogen lamp, a mini LED lamp and a fast LED lamp used for orthodontics cure for 40 seconds. The 3T3 Swiss cellular line of fibroblasts was used. The samples obtained were used to determine the cellular toxicity in vitro using the Neutral Red Up-take (NRU) and the 3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide (MTT) assay.

RESULTS

Toxicity of the extract appraised at a low level at MTT and NRU assays. There were statistically relevant differences between the toxicity induced by the auto-polymerizing material and the toxicity induced by the photo-polymerizing composite material, polymerized with the blue-light lamp (p < 0.001) and with the mini LED lamp (p < 0.05).

CONCLUSIONS

From the data collected in this study, we can conclude that both resins show a low level of cytotoxicity that, in the case of photochemical polymerizing resin, depends on the characteristics of the lamp.

Thrombopoietin Promotes Angiogenesis and Disease Progression in Patients with Multiple Myeloma

Multiple myeloma (MM) progression closely depends on bone marrow (BM) angiogenesis. Several factors sustain angiogenesis, including cytokines, growth factors, and cell-to-cell interactions. Herein, BM thrombopoietin (TPO) was shown to support angiogenesis and disease progression in MM. Patients with MM at different progression phases had higher levels of BM and circulating TPO than monoclonal gammopathy of undetermined significance/smoldering MM patients, suggesting that TPO correlates with disease progression and prognosis. Endothelial cells from patients with monoclonal gammopathy of undetermined significance (MGECs) and endothelial cells from MM (MMECs) expressed TPO receptor, and the TPO treatment triggered their angiogenic capabilities in vitro. Indeed, TPO-treated MGECs and MMECs showed enhanced angiogenesis on Matrigel and spontaneous cell migration and chemotaxis by acting as a chemotactic agent. TPO also had an angiogenic activity in vivo in the chorioallantoic membrane assay system. Finally, TPO treatment increased the release of active matrix metalloproteinase (MMP)-9 and MMP-2 in MGECs and of MMP-2 in MMECs and affected the balance between angiogenic/antiangiogenic factors in the MM BM. Our results support the angiogenic activity of TPO, and suggest that it may have a critical role in promoting the angiogenic switch during MM progression. Accordingly, TPO may be envisaged as a new angiogenic and prognostic factor in patients with MM.

Evaluation of the periodontal healing of the second mandibular molar distal site following insertion of PRF in the third molar post extraction alveolus

The aim of this study was to evaluate the periodontal healing of the distal sites of the mandibular second molars, comparing the extraction therapy of the third molar with and without PRF adjunct into the postextraction alveolus. The study sample was composed by 40 consecutive patients who underwent extraction of mandibular third molars. Patients were divided in two groups: the last 20 participants who have only been subjected to extraction (spontaneous healing group, SHG) and the first 20 patients who had PRF adjunct (PRF group, PG). Healing was evaluated by analyzing the variations in terms of PPD (Probing Pocket Depth), REC (Recession), CAL (Level of Clinical Attachment), BoP (Bleeding on Probing) and GI (Gingival Index) from Baseline to further follow-ups at 1 month and 3 months. The disto-vestibular (DV) and disto-lingual (DL) PPD values of the second mandibular molar were measured at Baseline and after three months in the two groups. Patients of the PG group showed lower PPD values at 1 month and 3 months postoperatively: DV: 3.6±1.09 - DL: 3.5±1.15 and DV: 2.5±0.83 - DL: 2.6±1.09, respectively. Patients belonging to the SHG also showed lower PPD values, reporting respectively the following DV values after 3 months: 2.7±0.86 - DL: 2.75±0. 85. However, there was no statistically significant difference comparing the results obtained in PG and SHG groups at 1 and 3 months (p>0.05). The insertion of PRF inside the post-extraction alveolus of the mandibular third molar leads to limited improvement in terms of periodontal healing, compared to extraction therapy only.

Quality of Life of Patients with Mandibular Third Molars and Mild Pericoronitis. A Comparison between Two Different Treatments: Extraction or Periodontal Approach

Background: The extraction of the mandibular third molar is one of the most frequent intervention in oral surgery. A common indication for wisdom tooth extraction is represented by pericoronitis, which can determine discomfort and pain in patients. The present study aimed to evaluate the impact of patients’ quality of life by comparing a surgical approach with a periodontal approach. Methods: We evaluated 82 patients diagnosed with pericoronitis that occurred at the third molar site. In total, 41 of them received a periodontal treatment and 41 were treated by extraction. The quality of life (QoL) of the patients was assessed by using the Oral Health Impact Profile-14 (OHIP-14) index. Results: A total of 82 patients were included in the study and were followed up for 6 months. Of the patients, 41 received a periodontal treatment and 41 underwent surgical extraction. At the baseline, the OHIP-14 scores of the surgical group were higher (19.71, SD 9.90) than the periodontal group (14.41, SD 8.71). At 1 week, there was a reduction in terms of OHIP-14 in both groups, but the periodontal group showed lower values (12.3, SD 8.11). Long-term follow-up showed a reduction of the OHIP-14 values, with a difference in favor of the surgical group (0.10, SD 0.45). However, there was a reduction in OHIP-14 scores in both groups. Conclusion: Although the periodontal treatment offered a rapid improvement in terms of quality of life during the first week after the treatment, after 1 month and 6 months, the extraction of the mandibular third molar extraction remained the best treatment, removing the occurrence of re-inflammation of the site.

FGF Trapping Inhibits Multiple Myeloma Growth through c-Myc Degradation-Induced Mitochondrial Oxidative Stress

Multiple myeloma, the second most common hematologic malignancy, frequently relapses because of chemotherapeutic resistance. Fibroblast growth factors (FGF) act as proangiogenic and mitogenic cytokines in multiple myeloma. Here, we demonstrate that the autocrine FGF/FGFR axis is essential for multiple myeloma cell survival and progression by protecting multiple myeloma cells from oxidative stress-induced apoptosis. In keeping with the hypothesis that the intracellular redox status can be a target for cancer therapy, FGF/FGFR blockade by FGF trapping or tyrosine kinase inhibitor impaired the growth and dissemination of multiple myeloma cells by inducing mitochondrial oxidative stress, DNA damage, and apoptotic cell death that were prevented by the antioxidant vitamin E or mitochondrial catalase overexpression. In addition, mitochondrial oxidative stress occurred as a consequence of proteasomal degradation of the c-Myc oncoprotein that led to glutathione depletion. Accordingly, expression of a proteasome-nondegradable c-Myc protein mutant was sufficient to avoid glutathione depletion and rescue the proapoptotic effects due to FGF blockade. These findings were confirmed on bortezomib-resistant multiple myeloma cells as well as on bone marrow-derived primary multiple myeloma cells from newly diagnosed and relapsed/refractory patients, including plasma cells bearing the t(4;14) translocation obtained from patients with high-risk multiple myeloma. Altogether, these findings dissect the mechanism by which the FGF/FGFR system plays a nonredundant role in multiple myeloma cell survival and disease progression, and indicate that FGF targeting may represent a therapeutic approach for patients with multiple myeloma with poor prognosis and advanced disease stage. SIGNIFICANCE: This study provides new insights into the mechanisms by which FGF antagonists promote multiple myeloma cell death. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/80/11/2340/F1.large.jpg.

Bone marrow fibroblasts overexpress miR-27b and miR-214 in step with multiple myeloma progression, dependent on tumour cell-derived exosomes

Aberrant microRNA (miR) expression has an important role in tumour progression, but its involvement in bone marrow fibroblasts of multiple myeloma patients remains undefined. We demonstrate that a specific miR profile in bone marrow fibroblasts parallels the transition from monoclonal gammopathy of undetermined significance (MGUS) to myeloma. Overexpression of miR-27b-3p and miR-214-3p triggers proliferation and apoptosis resistance in myeloma fibroblasts via the FBXW7 and PTEN/AKT/GSK3 pathways, respectively. Transient transfection of miR-27b-3p and miR-214-3p inhibitors demonstrates a cooperation between these two miRNAs in the expression of the anti-apoptotic factor MCL1, suggesting that miR-27b-3p and miR-214-3p negatively regulate myeloma fibroblast apoptosis. Furthermore, myeloma cells modulate miR-27b-3p and miR-214-3p expression in fibroblasts through the release of exosomes. Indeed, tumour cell-derived exosomes induce an overexpression of both miRNAs in MGUS fibroblasts not through a simple transfer mechanism but by de novo synthesis triggered by the transfer of exosomal WWC2 protein that regulates the Hippo pathway. Increased levels of miR-27b-3p and miR-214-3p in MGUS fibroblasts co-cultured with myeloma cell-derived exosomes enhance the expression of fibroblast activation markers αSMA and FAP. These data show that the MGUS-to-myeloma transition entails an aberrant miRNA profile in marrow fibroblasts and highlight a key role of myeloma cells in modifying the bone marrow microenvironment by reprogramming the marrow fibroblasts' behaviour. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Abstract C052: FGF trapping impairs multiple myeloma growth through c-Myc degradation-induced mitochondrial oxidative stress

Multiple myeloma (MM) remains incurable because of chemotherapeutic resistance. Fibroblast growth factors (FGF) play a pivotal role in MM by acting as an autocrine/paracrine mitogen on plasma cells, bone marrow-derived endothelial cells and fibroblasts. Also, a recurrent chromosomal translocation t(4;14) is associated with FGFR3 upregulation in MM patients. Thus, agents able to hamper FGF signaling may represent a novel approach for MM treatment. Recently we have identified the PTX3-derived small molecule NSC12 as the first orally active antitumor pan-FGF trap. Here, the role of FGF/FGFR system in MM cell survival and the therapeutic potential of NSC12 were investigated. In vitro effects of NSC12 were tested on four human MM cell lines harboring (KMS-11 and OPM-2 cells) or not (U-266 and RPMI8226 cells) the t(4:14) translocation and on patient-derived MM cells (N = 26). In vivo effects of FGF blockade were investigated using subcutaneous (KMS-11 and RPMI8226 cells) and systemic (MM-1S cells) xenografts grown in NOD/SCID mice. In addition, gene expression profiling (GEP) and gene set enrichment analyses (GSEA) were performed in NSC12-treated MM cells. NSC12 blocked the proliferation of all human MM cell lines tested, causing inhibition of FGFR signaling, downregulation of the anti-apoptotic protein mcl-1 and caspase 3 activation. Cytofluorimetric analysis revealed a significant increase of apoptotic cells as early as 6 hrs after NSC12 treatment, with 100% of cell death after 24 hrs even when MM cells were co-cultured with patient-derived bone marrow stromal cells. In vivo, NSC12 blocked FGFR activation and reduced the growth of subcutaneous xenografts and MM cell dissemination in the BM. GEP and GSEA analyses of NSC12-treated cells revealed the upregulation of oxidative stress-induced genes and the downmodulation of c-Myc targets. Accordingly, NSC12 caused the rapid proteasomal degradation of c-Myc paralleled by GSH depletion, mitochondrial ROS production and depolarization, DNA damage and finally apoptosis in KMS-11 cells but not in KMS-11 cells expressing the undegradable mutated (T58A) form of c-Myc. Interestingly, these findings were confirmed on Bortezomib-resistant MM cells as well as on bone marrow-derived primary MM cells from newly diagnosed and relapsed/refractory patients, including plasma cells bearing the t(4;14) translocation obtained from high-risk MM patients. Our data reveal that FGF blockade triggers MM mitochondrial oxidative stress, DNA damage and apoptotic cell death via the proteasomal degradation of the c-Myc oncoprotein. Altogether, our findings dissect for the first time the mechanism by which the FGF/FGFR system plays a non-redundant role in MM cell survival and disease progression, and indicate that FGF targeting may represent a therapeutic approach for MM patients with poor prognosis and advanced disease stage.

Citation Format: Roberto Ronca, Gaia Cristina Ghedini, Federica Maccarinelli, Antonio Sacco, Silvia Laura Locatelli, Eleonora Foglio, Sara Taranto, Elisabetta Grillo, Sara Matarazzo, Riccardo Castelli, Vanessa Desantis, Nadia Cattane, Annamaria Cattaneo, Marco Mor, Carmelo Carlo-Stella, Aldo Maria Roccaro, Marco Presta, Arianna Giacomini. FGF trapping impairs multiple myeloma growth through c-Myc degradation-induced mitochondrial oxidative stress [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr C052. doi:10.1158/1535-7163.TARG-19-C052

Autophagy: A New Mechanism of Prosurvival and Drug Resistance in Multiple Myeloma

Autophagy is an intracellular self-degradative process that balances cell energy source and regulates tissue homeostasis. In physiological condition, autophagy funnels cytoplasmic constituents to autophagolysosomes for degradation and is an alternative way for cell-death behavior. Here, we inspected autophagy as a prosurvival mechanism essential for drug resistance in multiple myeloma (MM). Accordingly, autophagy inhibitors used in association to conventional anti-MM drugs might enforce the effect against resistant MM plasma cells and render autophagy a new therapeutic target.

Belimumab restores Treg/Th17 balance in patients with refractory systemic lupus erythematosus

Belimumab, a specific inhibitor of the soluble B lymphocyte stimulator (BlyS), is the first biological drug approved by the United States Food and Drug Administration for the treatment of patients with active systemic lupus erythematosus (SLE) refractory to standard therapy. Given that an imbalance between regulatory T cells (Treg) and interleukin (IL)-17A-secreting T cells (Th17) has been reported in various autoimmune disorders, we assessed the frequency of both Treg and Th17 peripheral blood populations before and after belimumab administration in 20 patients with active SLE refractory to standard therapy. After six months of treatment, the mean SELENA-SLEDAI score as well as the mean anti-double-stranded DNA antibody titers were significantly decreased. In addition, we observed a significant increase in Treg percentages and a parallel, significant decrease in Th17 percentages, accompanied by significantly reduced serum levels of IL-21. In vitro studies showed that Treg purified from belimumab-treated patients were fully functional and displayed a suppressor function similar to that of Treg purified from healthy donors. Belimumab can restore Treg/Th17 balance in SLE patients with uncontrolled disease activity, and this results in decreased flare rate and reduced glucocorticoid dosage.

Inhibition of mTOR complex 2 restrains tumor angiogenesis in multiple myeloma

The mammalian Target of Rapamycin (mTOR) is an intracellular serine/threonine kinase that mediates intracellular metabolism, cell survival and actin rearrangement. mTOR is made of two independent complexes, mTORC1 and mTORC2, activated by the scaffold proteins RAPTOR and RICTOR, respectively. The activation of mTORC1 triggers protein synthesis and autophagy inhibition, while mTORC2 activation promotes progression, survival, actin reorganization, and drug resistance through AKT hyper-phosphorylation on Ser473. Due to the mTOR pivotal role in the survival of tumor cells, we evaluated its activation in endothelial cells (ECs) from 20 patients with monoclonal gammopathy of undetermined significance (MGUS) and 47 patients with multiple myeloma (MM), and its involvement in angiogenesis. MM-ECs showed a significantly higher expression of mTOR and RICTOR than MGUS-ECs. These data were supported by the higher activation of mTORC2 downstream effectors, suggesting a major role of mTORC2 in the angiogenic switch to MM. Specific inhibition of mTOR activity through siRNA targeting RICTOR and dual mTOR inhibitor PP242 reduced the MM-ECs angiogenic functions, including cell migration, chemotaxis, adhesion, invasion, in vitro angiogenesis on Matrigel^®, and cytoskeleton reorganization. In addition, PP242 treatment showed anti-angiogenic effects in vivo in the Chick Chorioallantoic Membrane (CAM) and Matrigel^® plug assays. PP242 exhibited a synergistic effect with lenalidomide and bortezomib, suggesting that mTOR inhibition can enhance the anti-angiogenic effect of these drugs. Data to be shown indicate that mTORC2 is involved in MM angiogenesis, and suggest that the dual mTOR inhibitor PP242 may be useful for the anti-angiogenic management of MM patients.

Rhu-Epo down-regulates pro-tumorigenic activity of cancer-associated fibroblasts in multiple myeloma

We have previously demonstrated that recombinant human erythropoietin (rHuEpo) is involved in the regulation of the angiogenic response in multiple myeloma (MM) through a direct effect on macrophages and endothelial cells isolated from the bone marrow of patients with MM. The aim of the present study was designed to determine the effects of rHuEpo on cancer-associated fibroblasts (CAFs) from monoclonal gammopathy of undetermined significance (MGUS) and MM patients by means of in vitro and in vivo assays. rHuEpo treatment reduces the expression of mRNA levels of fibroblast activation markers, namely alpha smooth actin (αSMA) and fibroblast activation protein (FAP) in MGUS and MM CAFs, and of pro-inflammatory and pro-angiogenic cytokines, including interleukin (IL)-6 and IL-8, vascular endothelial growth factor-A (VEGF-A), fibroblast growth factor-2 (FGF-2), and hepatocyte growth factor (HGF) in MM CAFs. Moreover, rHuEpo inhibits the proliferative activity of MM CAFs and increased the apoptosis of MGUS and MM CAFs. Overall, these data suggest that rHu-Epo down-regulates CAFs pro-tumorigenic activity. Moreover, these results are not suggestive for a pro-angiogenic activity of rHuEpo on CAFs. In fact, rHuEpo pre-treatment induces a low angiogenic response in vivo in the chorioallantoic membrane (CAM) assay of MGUS and MM CAFs conditioned medium, not comparable to that of a well-known angiogenic cytokine, VEGF-A, tested in the same assay.

Targeting angiogenesis in multiple myeloma by the VEGF and HGF blocking DARPin® protein MP0250: a preclinical study

The investigational drug MP0250 is a multi-specific DARPin^® molecule that simultaneously binds and neutralizes VEGF and HGF with high specificity and affinity. Here we studied the antiangiogenic effects of the MP0250 in multiple myeloma (MM). In endothelial cells (EC) isolated from bone marrow (BM) of MM patients (MMEC) MP0250 reduces VEGFR2 and cMet phosphorylation and affects their downstream signaling cascades. MP0250 influences the secretory profile of MMEC and inhibits their in vitro angiogenic activities (spontaneous and chemotactic migration, adhesion, spreading and capillarogenesis). Compared to anti-VEGF or anti-HGF neutralizing mAbs, MP0250 strongly reduces capillary network formation and vessel-sprouting in a Matrigel angiogenesis assay. MP0250 potentiates the effect of bortezomib in the same in vitro setting. It significantly reduces the number of newly formed vessels in the choriollantoic membrane assay (CAM) and the Matrigel plug assay. In the syngeneic 5T33MM tumor model, MP0250 decreases the microvessel density (MVD) and the combination MP0250/bortezomib lowers the percentage of idiotype positive cells and the serum levels of M-protein. Overall results define MP0250 as a strong antiangiogenic agent with potential as a novel combination drug for treatment of MM patients.

Abstract B134: Inhibition of the fibroblast growth factor system by a new FGF trap induces oxidative stress and mitochondrial apoptosis in multiple myeloma cells

Despite advances in systemic and supportive therapies, multiple myeloma (MM) remains incurable because of chemotherapeutic resistance. Fibroblast growth factor-2 (FGF2) plays a pivotal role in MM by acting as an autocrine/paracrine mitogen on plasma cells, bone marrow-derived endothelial cells, and fibroblasts. In keeping with the pivotal role of the FGF system in MM, a recurrent chromosomal translocation t(4;14) is associated with upregulation of FGF receptor-3 (FGFR3) in MM patients. Agents able to hamper FGF signaling are therefore of interest as a novel approach for the treatment of MM. The soluble pattern recognition receptor long pentraxin-3 (PTX3) owns a unique FGF-binding N-terminal domain. Structural/functional characterization of this domain led to the characterization of the pentapeptide ARPCA as a potent FGF antagonist in vitro and in vivo. Subsequently, molecular modeling based on ARPCA structure and small-molecule library fishing have allowed the identification of a novel, orally active 480 Da FGF trap (NSC12) able to hamper tumor growth and vascularization in FGF-driven human lung and prostate tumor models. Here, the therapeutic potential of NSC12 for MM treatment was tested on four human MM cell lines harboring (KMS-11 and OPM-2 cells) or not (U-266 and RPMI8226 cells) the t(4:14) translocation. NSC12 blocked the proliferation of all human MM cell lines with an IC50 ≅ 3 µM. Western blot analysis showed that NSC12 inhibited the activation of FGFR3 signaling and strongly downregulated the antiapoptotic protein mcl-1, leading to the activation of caspase 3. Cytofluorimetric analysis revealed a significant increase of annexin-V+ apoptotic cells as early as 6 hrs after NSC12 treatment, with 100% of cell death after 24 hrs of treatment. Interestingly, apoptosis was observed even when MM cells were cocultured with patient-derived bone marrow stromal cells. In vivo, oral delivery of NSC12 significantly blocked the growth of KMS-11 (286.9 ± 22.4 vs 459.8 ± 27.4 mm3, p&lt;0.001) and RPMI8226 (141.5 ± 17.7 vs 245.9 ± 46.4 mm3, p&lt;0.001) xenografts injected subcutaneously in immune-compromised NOD/SCID mice. Analysis of tumor xenografts from NSC12-treated mice showed a strong increase of TUNEL-positive apoptotic cells and a significant reduction of CD31-positive tumor vascularization compared to xenografts from vehicle-treated mice. In an attempt to get further insights into the proapoptotic mechanism of action of NSC12 in MM cells, we found that NSC12 treatment rapidly induces a significant and progressive increase of mitochondrial depolarization paralleled by massive mitochondrial ROS production, suggesting a key role of mitochondria dysfunction in NSC12-induced MM cell death. In addition, as observed for MM cell lines, NSC12 treatment of patient-derived MM cells (N. of patients=14) strongly reduced FGFR3 phosphorylation and mcl-1 levels and induced the upregulation of oxidative stress-induced genes accompanied by apoptosis. Altogether, these data suggest that NSC12 affects MM tumor growth through a direct cytotoxic activity on MM cells and by inhibiting FGF-mediated paracrine/autocrine crosstalk in the tumor stroma/microenvironment. Thus, NSC12 may represent a novel “two compartment” inhibitor in MM by hampering FGF-dependent angiogenic/oncogenic signaling.

Citation Format: Arianna Giacomini, Gaia Cristina Ghedini, Federica Maccarinelli, Silvia Laura Locatelli, Antonio Sacco, Riccardo Castelli, Vanessa Desantis, Aldo Maria Roccaro, Marco Mor, Carmelo Carlo-Stella, Roberto Ronca, Marco Presta. Inhibition of the fibroblast growth factor system by a new FGF trap induces oxidative stress and mitochondrial apoptosis in multiple myeloma cells [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr B134.

Myeloma cells act as tolerogenic antigen-presenting cells and induce regulatory T cells in vitro

Regulatory T cells (Tregs) are essential for maintenance of self-tolerance; however, tumor cells can exploit the tolerance to escape the immune system. We investigated the Tregs frequency in patients with multiple myeloma (MM) and in those with monoclonal gammopathy of undetermined significance (MGUS), and found that CD4(+) FoxP3(+) and CD8(+) FoxP3(+) Tregs were significantly increased in patients with MM and correlated with the active phase. Both Tregs subsets were expanded in cocultures of CD3(+) lymphocytes and fresh CD138(+) MM plasma cells or RPMI8226 and U266 cell lines and functioned as natural (n) and inducible (i) Tregs insofar as they inhibited the proliferation of stimulated CD3 lymphocytes via contact-dependent and contact-independent pathways. Induction of Tregs by MM plasma cells required a contact-dependent pathway, implying antigen recognition by T cells. MM plasma cells acted as immature and tolerogenic antigen-presenting cells (APCs), in that they displayed low CD80/CD86 expression associated with a phagocytic activity. By acting as immature APCs, MM plasma cells plausibly expand (n)Tregs and (i)Tregs both through conversion of CD3(+) FoxP3(-) into CD3(+) FoxP3(+) T cells and proliferation of CD3(+) FoxP3(+) T cells, which may suppress the anti-MM immune response.