Caratteristiche cliniche ed ecografiche dei Sarcomi Uterini

Obiettivo: descrivere le caratteristiche ecografiche e flussimetriche dei sarcoma uterini Materiali e Metodi: Dall'archivio anatomopatologico di due cliniche Universitarie sono state reclutate retrospettivamente tutte le pazienti con diagnosi anatomopatologica di sarcoma uterino. Tutte le cartelle cliniche, le immagini e i filmati digitalizzati sono stati analizzati e dati raccolti in un database. Risultati: Sono stati inclusi nello studio 49 casi, che comprendono 17 leiomiosarcoma, 14 sarcoma dello stroma endometriale e 18 carcinosarcoma. L'età media alla diagnosi è stata 62 anni (range 35-87). L'ottanta per cento delle pazienti erano in menopausa al momento della diagnosi. Circa la metà delle pazienti presentavano sanguinamento anomalo e il 20% dolore pelvico. La maggior parte delle lesioni sono apparse iso-ipoecogene, senza coni d’ombra (47/49;96%). Conclusioni: I sarcomi uterini sono un gruppo eterogeneo di tumori che presentano aspetti ecografici diversi anche in relazione all’istotipo. Conoscere le diverse caratteristiche può essere utile ai fini di una corretta diagnosi. Nel nostro studio l’assenza dei coni d’ombra risulta essere l’aspetto più significativo.

Alterazioni dell'immunità umorale nei pazienti con sarcoma di Kaposi classico: caratterizzazione dei linfociti B circolanti e delle loro sottopopolazioni

Objectives: Human Herpesvirus 8 (HHV-8) is the etiological agent of Kaposi’s Sarcoma (KS) and it is also associated with two B cell lymphoproliferative diseases: primary effusion lymphoma (PEL), and the plasmablastic form of multicentric Castelman’s disease (MCD). HHV-8 establishes persistent infection in the host with tropism for multiple cell types. In KS patients, the virus is found in tumor-spindle cells, peripheral blood monocytes, endothelial progenitor circulating cells, T and B lymphocytes. Peripheral B cells represent one of the major virus reservoir, but the consequences of HHV-8 infection of these cells have been poorly characterized. Therefore, in this study the frequency, the immunophenotypic profile and the functional activity of different peripheral B cell subsets in patients with classic KS (cKS) was analysed in order to identify potential alterations of these cells. The classic variant of KS is ideal to perform such studies, as it lacks confounding factors such as HIV or EBV infection and immunosuppression. Methods: Whole-blood samples from patients with the classical form of KS (cKS) (n=62) and healthy age and sex-matched seronegative controls (HSN) (n=43) were analyzed by multiparametric flow-cytometry to determine the frequency of B cells and their subpopulations, as well as their surface expression of immunoglobulins and activation markers. Results: The frequency of circulating B cells was significantly higher in cKS patients than in controls. In particular, the analysis of the B cell subsets revealed a higher frequency of naïve B cells (CD19+CD27-), among which transitional CD19+CD38highCD5+ and pre-naïve (CD27-CD38intCD5+ ) B cells demonstrated an expansion. Memory B cells (CD19+CD27+) did not differ between the two study groups, except from a higher frequency of CD19+CD27+IgM+IgD+ B cells, the typical phenotype of marginal zone (MZ) B cells, in cKS patients. The characterization of membrane surface activation markers showed lower levels of the activation marker HLA-DR only on CD27- B cells, while CD80 and CD86 were less represented in all the the B cells from cKS patients. Moreover, B cells from cKS patients were smaller and with less granules than the ones from controls. Conclusion: Taken together, these results clearly indicate that circulating B cells are altered in patients with cKS, showing an expansion of the immature phenotypes. These B cell alterations may be due to an indirect viral effect rather than to a direct one: the cytokines expressed in the microenvironment typical of cKS may cause a faster release of immature cells from the bone marrow and a lower grade of peripheral differentiation, as already suggested for other chronic viral infections such as HIV and HCV. Further studies will be necessary to understand how these alterations contribute to the pathogenesis of KS and, eventually, to the different clinical evolution of the disease.

Identificazione di fattori trascrizionali associati al differenziamento neurale in cellule di sarcoma di Ewing: ruolo di NF-kB

Il sarcoma di Ewing (ES) è un tumore maligno pediatrico dell’apparato scheletrico; è associato a una traslocazione specifica codificante la proteina di fusione EWS-FLI1 e all’alta espressione di CD99, una glicoproteina di membrana fisiologicamente coinvolta in diversi processi biologici. EWS-FLI1 e CD99, sono riportati avere ruoli divergenti nella modulazione della malignità e del differenziamento di ES. CD99 inoltre è riportato modulare il pathway di MAPK, il quale interagendo con molteplici fattori di trascrizione partecipa a processi di proliferazione e differenziamento. In questo studio abbiamo investigato in due linee cellulari di ES silenziate per CD99 (TC-71shCD99 e IOR/CARshCD99) l’attività basale di diversi fattori trascrizionali quali: NF-kBp65, AP1, Elk-1, E2F e CREB. L’unico fattore trascrizionale statisticamente significativo è risultato essere NF-kBp65 e abbiamo valutato il suo ruolo nel differenziamento neurale di cellule di ES e la relazione con EWS-FLI1 e CD99. L’attività trascrizionale di NF-kB è stata valutata attraverso gene reporter assay in linee cellulari di ES a diversa espressione di CD99, EWS-FLI1 e NF-kB stesso. Il differenziamento neurale è stato valutato come espressione di βIII-Tubulin in immunofluorescenza. Il silenziamento di CD99 induce una down-modulazione dell’attività trascrizionale di NF-kB, mentre il knockdown di EWS-FLI1 ne induce un’aumento. Inoltre, il silenziamento di EWS-FLI1 non è in grado di contrastare la riduzione dell’attività di NF-kB osservata dopo silenziamento di CD99, suggerendo un ruolo dominante del CD99 nel signaling di NF-kB. Cellule deprivate di CD99 ma non di EWS-FLI1, mostrano un fenotipo differenziato in senso neurale, fenotipo che viene perso quando le cellule sono indotte a sovraesprimere NF-kB. Inoltre, in cellule CD99 positive, il silenziamento di NF-kB induce un leggero differenziamento neurale. In conclusione, questi dati hanno evidenziato il ruolo di NF-kB nel differenziamento di cellule di ES e che potrebbe essere un potenziale target nel ridurre la progressione di questo tumore.

Mesenchymal stromal cell: new applications for regenerative medicine

In the last decades mesenchymal stromal cells (MSC), intriguing for their multilineage plasticity and their proliferation activity in vitro, have been intensively studied for innovative therapeutic applications. In the first project, a new method to expand in vitro adipose derived-MSC (ASC) while maintaining their progenitor properties have been investigated. ASC are cultured in the same flask for 28 days in order to allow cell-extracellular matrix and cell-cell interactions and to mimic in vivo niche. ASC cultured with this method (Unpass cells) were compared with ASC cultured under classic condition (Pass cells). Unpass and Pass cells were characterized in terms of clonogenicity, proliferation, stemness gene expression, differentiation in vitro and in vivo and results obtained showed that Unpass cells preserve their stemness and phenotypic properties suggesting a fundamental role of the niche in the maintenance of ASC progenitor features. Our data suggests alternative culture conditions for the expansion of ASC ex vivo which could increase the performance of ASC in regenerative applications. In vivo MSC tracking is essential in order to assess their homing and migration. Super-paramagnetic iron oxide nanoparticles (SPION) have been used to track MSC in vivo due to their biocompatibility and traceability by MRI. In the second project a new generation of magnetic nanoparticles (MNP) used to label MSC were tested. These MNP have been functionalized with hyperbranched poly(epsilon-lysine)dendrons (G3CB) in order to interact with membrane glycocalix of the cells avoiding their internalization and preventing any cytotoxic effects. In literature it is reported that labeling of MSC with SPION takes long time of incubation. In our experiments after 15min of incubation with G3CB-MNP more then 80% of MSC were labeled. The data obtained from cytotoxic, proliferation and differentiation assay showed that labeling does not affect MSC properties suggesting a potential application of G3CB nano-particles in regenerative medicine.

Cell death mechanisms triggered by monoclonal antibodies against CD99 in Ewing sarcoma: Cross-talk between MDM2, IGF-1R and Ras/MAPK

CD99 is a 32 kDa transmembrane protein whose high expression characterizes Ewing sarcoma (ES), a very aggressive pediatric bone tumor. In addition to its diagnostic value, CD99 has therapeutic potential since it leads to rapid and massive ES cell death when engaged with specific antibodies. Here a novel mechanism of cell death triggered via CD99 is shown, leading, ultimately, to the appearance of macropinocytotic vescicles. Anti-CD99 mAb 0662 induces MDM2 ubiquitination and degradation, which causes not only a p53 reactivation but also the IGF-1R induction and its subsequent internalization; CD99 results internalized together with IGF-1R inside endosomes, but then the two molecules display a different sorting: CD99 is degraded, while IGF-1R is recycled on the surface, causing, as a final step, the up-regulation of RAS-MAPK. High-expressing CD99 mesenchymal stem cells show mild Ras induction but no p53 activation and escape cell death, but in presence of EWS/FLI1 mesenchymal stem cells expressing CD99 show a stronger Ras induction and a p53 reactivation, leading to a significant cell death rate. We propose that CD99 triggering in a EWS/FLI1-driven oncogenetic context creates a synergy between RAS upregulation and p53 activation in ES cells, leading to cell death. Moreover, our data rule out possible concerns on toxicity related to the broad CD99 expression in normal tissues and provide the rationale for the therapeutic use of anti-CD99 MAbs in the clinic.

Mesenchymal Stromal Cells (MSCs) and induced Plutipotent Stem Cells (iPSCs) in Domestic Animals: Characterization and Differentiation Potential

Derivation of stem cell lines from domesticated animals has been of great interest as it benefits translational medicine, clinical applications to improve human and animal health and biotechnology. The main types of stem cells studied are Embryonic Stem Cells (ESCs), induced Pluripotent Stem Cells (iPSCs) and Mesenchymal Stem/Stromal Cells (MSCs). This thesis had two main aims: (I) The isolation of bovine MSCs from amniotic fluid (AF) at different trimesters of pregnancy and their characterization to study pluripotency markers expression. Stemness markers were studied also in MSCs isolated from equine AF, Wharton’s jelly (WJ) and umbilical cord blood (UCB) as continuation of the characterization of these cells previously performed by our research group; (II) The establishment and characterization of iPSCs lines in two attractive large animal models for biomedical and biotechnology research such as the bovine and the swine, and the differentiation into the myogenic lineage of porcine iPSCs. It was observed that foetal tissues in domestic animals such as the bovine and the horse represent a source of MSCs able to differentiate into the mesodermal lineage but they do not proliferate indefinitely and they lack the expression of many pluripotency markers, making them an interesting source of cells for regenerative medicine, but not the best candidate to elucidate pluripotency networks. The protocol used to induce pluripotency in bovine fibroblasts did not work, as well as the chemical induction of pluripotency in porcine fibroblasts, while the reprogramming protocol used for porcine iPSCs was successful and the line generated was amenable to being differentiated into the myogenic lineage, demonstrating that they could be addressed into a desired lineage by genetic modification and appropriated culture conditions. Only a few cell types have been differentiated from domestic animal iPSCs to date, so the development of a reliable directed-differentiation protocol represents a very important result.

IGF system, CD99 and tumor-specific chromosomal translocations: evaluation of their cross-talk and definition of their role in Ewing sarcoma and prostate cancer

Aberrant expression of ETS transcription factors, including FLI1 and ERG, due to chromosomal translocations has been described as a driver event in initiation and progression of different tumors. In this study, the impact of prostate cancer (PCa) fusion gene TMPRSS2-ERG was evaluated on components of the insulin-like growth factor (IGF) system and the CD99 molecule, two well documented targets of EWS-FLI1, the hallmark of Ewing sarcoma (ES). The aim of this study was to identify common or distinctive ETS-related mechanisms which could be exploited at biological and clinical level. The results demonstrate that IGF-1R represents a common target of ETS rearrangements as ERG and FLI1 bind IGF-1R gene promoter and their modulation causes alteration in IGF-1R protein levels. At clinical level, this mechanism provides basis for a more rationale use of anti-IGF-1R inhibitors as PCa cells expressing the fusion gene better respond to anti-IGF-1R agents. EWS-FLI1/IGF-1R axis provides rationale for combination of anti-IGF-1R agents with trabectedin, an alkylator agent causing enhanced EWS-FLI1 occupancy on the IGF-1R promoter. TMPRSS2-ERG also influences prognosis relevance of IGF system as high IGF-1R correlates with a better biochemical progression free survival (BPFS) in PCa patients negative for the fusion gene while marginal or no association was found in the total cases or TMPRSS2-ERG-positive cases, respectively. This study indicates CD99 is differentially regulated between ETS-related tumors as CD99 is not a target of ERG. In PCa, CD99 did not show differential expression between TMPRSS2-ERG-positive and –negative cells. A direct correlation was anyway found between ERG and CD99 proteins both in vitro and in patients putatively suggesting that ERG target genes comprehend regulators of CD99. Despite a little trend suggesting a correlation between CD99 expression and a better BPFS, no clinical relevance for CD99 was found in the field of prognostic biomarkers.

Contribution of vascular resident mesenchymal stromal cells to abdominal aortic aneurysm pathogenesis: increased MMP-9 expression and ineffective immunomodulation

Background. Ageing and inflammation are critical for the occurrence of aortic diseases. Extensive inflammatory infiltrate and excessive ECM proteloysis, mediated by MMPs, are typical features of abdominal aortic aneurysm (AAA). Mesenchymal Stromal Cells (MSCs) have been detected within the vascular wall and represent attractive candidates for regenerative medicine, in virtue of mesodermal lineage differentiation and immunomodulatory activity. Meanwhile, many works have underlined an impaired MSC behaviour under pathological conditions. This study was aimed to define a potential role of vascular MSCs to AAA development. Methods. Aortic tissues were collected from AAA patients and healthy donors. Our analysis was organized on three levels: 1) histology of AAA wall; 2) detection of MSCs and evaluation of MMP-9 expression on AAA tissue; 3) MSC isolation from AAA wall and characterization for mesenchymal/stemness markers, MMP-2, MMP-9, TIMP-1, TIMP-2 and EMMPRIN. AAA-MSCs were tested for immunomodulation, when cultured together with activated peripheral blood mononuclear cells (PBMCs). In addition, a co-colture of both healthy and AAA MSCs was assessed and afterwards MMP-2/9 mRNA levels were analyzed. Results. AAA-MSCs showed basic mesenchymal properties: fibroblastic shape, MSC antigens, stemness genes. MMP-9 mRNA, protein and enzymatic activity were significantly increased in AAA-MSCs. Moreover, AAA-MSCs displayed a weak immunosuppressive activity, as shown by PBMC ongoing along cell cycle. MMP-9 was shown to be modulated at the transcriptional level through the direct contact as well as the paracrine action of healthy MSCs. Discussion. Vascular injury did not affect the MSC basic phenotype, but altered their function, a increased MMP-9 expression and ineffective immunmodulation. These data suggest that vascular MSCs can contribute to aortic disease. In this view, the study of key processes to restore MSC immunomodulation could be relevant to find a pharmacological approach for monitoring the aneurysm progression.