42 research outputs found

    Synthesis and functionalization of casein nanoparticles with aptamers for triple-negative breast cancer targeting

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    This work shows the synthesis of a drug delivery system made of casein nanoparticles able to host hydrophobic molecules and be functionalized with aptamers targeting the epidermal growth factor receptor. In vitro cell viability and uptake analyses, performed on triple-negative breast cancer cells, confirmed the safety profile and the target selectivity

    Inhibition of Bone Marrow-Derived Mesenchymal Stem Cells Homing Towards Triple-Negative Breast Cancer Microenvironment Using an Anti-PDGFRβ Aptamer

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    Bone marrow-derived mesenchymal stem cells (BM-MSCs) are shown to participate in tumor progression by establishing a favorable tumor microenvironment (TME) that promote metastasis through a cytokine networks. However, the mechanism of homing and recruitment of BM-MSCs into tumors and their potential role in malignant tissue progression is poorly understood and controversial. Here we show that BM-MSCs increase aggressiveness of triple-negative breast cancer (TNBC) cell lines evaluated as capability to migrate, invade and acquire stemness markers. Importantly, we demonstrate that the treatment of BM-MSCs with a nuclease-resistant RNA aptamer against platelet-derived growth factor receptor β (PDGFRβ) causes the inhibition of receptor-dependent signaling pathways thus drastically hampering BM-MSC recruitment towards TNBC cell lines and BM-MSCs trans-differentiation into carcinoma-associated fibroblast (CAF)-like cells. Moreover, in vivo molecular imaging analysis demonstrated the aptamer ability to prevent BM-MSCs homing to TNBC xenografts. Collectively, our results indicate the anti-PDGFRβ aptamer as a novel therapeutic tool to interfere with BM-MSCs attraction to TNBC providing the rationale to further explore the aptamer in more complex pre-clinical settings

    PO-038 PDGFRβ as a new biomarker for metastatic triple-negative breast cancer: development of a theranostic anti-PDGFRβ aptamer for imaging and suppression of metastases

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    Introduction Triple-negative breast cancers (TNBCs) are a heterogeneous group of aggressive tumours lacking oestrogen and progesterone receptors and HER2 receptor, thus excluding the possibility of using targeted therapy against these proteins. Mesenchymal-like (ML) subtype, characterised by a stem-like, undifferentiated phenotype, is more invasive and metastatic than other TNBC subtypes and has a strong tendency to form vasculogenic mimicry (VM). Recently, platelet derived growth factor receptor β (PDGFRβ) has been shown to play a role in VM of TNBC. Regrettably, therapies targeting PDGFRβ with tyrosine kinase inhibitors are not effective in treating TNBCs, thus developing new strategies to target PDGFRβ in TNBC patients is crucial to improve their chances of survival. Here, we describe the characterisation of the Gint4.T anti-PDGFRβ nuclease-resistant RNA aptamer as high efficacious theranostic tool for imaging and suppression of ML TNBC metastases. Material and methods Immunohistochemical analyses on a human TNBC tissue microarray was performed to correlate PDGFRβ expression with clinical and molecular features of different subtypes. Functional assays were conducted on PDGFRβ-positive ML BT-549 and MDA-MB-231 cells to investigate the effect of Gint4.T in interfering with cell growth in 3D conditions, migration, invasion and VM formation. Gint4.T was conjugated with near-infrared (NIR) fluorescent VivoTag-S680 and its binding specificity to receptor was confirmed both in vitro (confocal microscopy and flow cytometry analyses of TNBC cells) and in vivo (fluorescence molecular tomography in mice bearing TNBC xenografts). MDA-MB-231 cells were i.v. injected in nude mice and Gint4.T-NIR was used to detect lung metastases in mice untreated or i.v. injected with Gint4.T or a scrambled aptamer. Results and discussions The expression of PDGFRβ was observed in human TNBC samples characterised by higher metastatic behaviour. Treatment of TNBC cell lines with Gint4.T aptamer blocked their invasive growth and vasculogenic properties in 3D culture conditions, and strongly reduced cell migration/invasion in vitro and metastases formation in vivo. The Gint4.T-NIR was able to specifically bind to TNBC xenografts and detect lung metastases in vivo. Therefore, the aptamer revealed a high efficacious theranostic tool for imaging and suppression of TNBC metastases. Conclusion These studies indicate PDGFRβ as a new biomarker for ML and metastatic TNBC subtype and propose a novel targeting agent for the diagnosis and treatment of metastatic TNBCs

    Mappatura di precisione delle aree di pertinenza del fiume Arno nella Provincia di Firenze

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    Mappatura Di Precisione Delle Aree Di Pertinenza Del Fiume Arno Nella Provincia Di Firenz

    Evaluation of the impact in tennis serve and analysis of body segments position

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    The aim of this study is to find the impact instant and than to examine the position of the body segments and angles of the upper arm, during first serve. We have also calculated the post-impact ball velocity, the pre-impact racket centre velocity and its angular velocity too. Data were collected from six right-handed middle and young players during a training session, analyzed with Simi Motion System (50Hz). The impact event resulted more precise with the pre- and post-impact position of the racket centre connecting to the last frame of the fall of the ball after release, using raw data. The post-impact resultant velocity of the ball is lower than the professional tennis players (male 13.5m/s, female 5m/s). The angular velocity of the racket between the two frames of impact is variable by 55.5 to 26.2rad/s. The positions of the body segments show a big variability because we analyzed in and out serves

    Kinematic relations between first and second serve in tennis

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    Introduction The ball displacement, the racket (R) and ball post-impact velocity (v) in first (F) and second (S) serves were analysed by [1]. The aren’t studies about the body displacement as regards the R. The aim of this study is to find the differences between the F and S serve about the ball and R kinematics data and body positions. Methods 4 right-handed subjects (age 17,5 ±7; 450 ATP 4.4 NR) performed 16 serves. The best F and S serve (qualitative ob.) from left to right were analysed. 3 50Hz cameras were located outside the court. The serve area was calibrated. Simi Motion Analysis Syst. was used for a manual digitalization to obtain 3D coordinate data. We digitized 28 points (body, R, ball). Exel, Matlab and Spss were used to draw up the data. The determination of the instant of impact were made by [2]. Results The linear ball v at impact are significant (Freidman T.

    Profiling cancer cells by cell-selex: Use of aptamers for discovery of actionable biomarkers and therapeutic applications thereof

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    The identification of tumor cell-specific surface markers is a key step towards personalized cancer medicine, allowing early assessment and accurate diagnosis, and development of efficacious targeted therapies. Despite significant efforts, currently the spectrum of cell membrane targets associated with approved treatments is still limited, causing an inability to treat a large number of cancers. What mainly limits the number of ideal clinical biomarkers is the high complexity and heterogeneity of several human cancers and still-limited methods for molecular profiling of specific cancer types. Thanks to the simplicity, versatility and effectiveness of its application, cell-SELEX (Systematic Evolution of Ligands by Exponential Enrichment) technology is a valid complement to the present strategies for biomarkers’ discovery. We and other researchers worldwide are attempting to apply cell-SELEX to the generation of oligonucleotide aptamers as tools for both identifying new cancer biomarkers and targeting them by innovative therapeutic strategies. In this review, we discuss the potential of cell-SELEX for increasing the currently limited repertoire of actionable cancer cell-surface biomarkers and focus on the use of the selected aptamers as components of innovative conjugates and nano-formulations for cancer therapy

    Novel Human Bispecific Aptamer-Antibody Conjugates for Efficient Cancer Cell Killing

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    Monoclonal antibodies have been approved by the Food and Drug Administration for the treatment of various human cancers. More recently, oligonucleotide aptamers have risen increasing attention for cancer therapy thanks to their low size (efficient tumor penetration) and lack of immunogenicity, even though the short half-life and lack of effector functions still hinder their clinical applications. Here, we demonstrate, for the first time, that two novel bispecific conjugates, consisting of an anti-epidermal growth factor receptor (EGFR) aptamer linked either with an anti-epidermal growth factor receptor 2 (ErbB2) compact antibody or with an immunomodulatory (anti-PD-L1) antibody, were easily and rapidly obtained. These novel aptamer-antibody conjugates retain the targeting ability of both the parental moieties and acquire a more potent cancer cell killing activity by combining their inhibitory properties. Furthermore, the conjugation of the anti-EGFR aptamer with the immunomodulatory antibody allowed for the efficient redirection and activation of T cells against cancer cells, thus dramatically enhancing the cytotoxicity of the two conjugated partners. We think that these bispecific antibody-aptamer conjugates could have optimal biological features for therapeutic applications, such as increased specificity for tumor cells expressing both targets and improved pharmacokinetic and pharmacodynamic properties due to the combined advantages of the aptamer and antibody

    Visuomotor orientation in 6 to 11 old children: comparison between tennis and not tennis player

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    INTRODUCTION. Several studies showed differences in visual information acquisition and motor task response between normal subjects and athletes: hockey (Enns, Richards, 1997), volley (Ripoll, 1988), tennis (Castello e Umilt\ue0, 1988). There is scarce literature about children in prepubertal age (Lambert et al, 2005; Ferrel et al, 2001). AIM. of this study was to compare the children ocular orientation between tennis (TP) and not tennis players (NTP) and to verify the specific sport practice influence on perceptive abilities development. METHODS. The study involved 29 subjects aged 6-12 (mean 9,1): 8 f., 21 m; NTP: 17;TP: 12. Experimental test consisted of exposing the subjects to the vision of a video recorded sequence (38 sec.long) showing a tennis instructor performing service, forehand and backhand techniques. Sequence was observed two time with different clues: a) free vision; b) restricted area vision (follow the ball trajectory). Ocular movements were recorded by the EyeLink II API Computer System\u2019s protocol at a frequency of 500 Hz. Interest areas were plotted on the video to verify the ocular orientation position on instructor area, left and right field area. Total number and time of ocular fixations on the screen were recorded for each subject. Mann-Whitney non parametric test for independent samples were used for the statistical analysis. DISCUSSION. In condition \u201ca\u201d no significant differences were found between NTP and TP (p>.05). In condition \u201cb\u201d significant differences were found in the following parameters: Total fixation Instructor Left area %Instructor %Left area area fix. fix. area fix. fix. p= ,049 p= ,001 p= ,014 p= ,007 p= ,014 NTP 80,70\ub115,46 26,30\ub18,31 8,80\ub12,20 51,54\ub125,67 17,37\ub12,92 TP 65,88\ub16,64 6,38\ub13,70 20,25\ub19,13 25,67\ub119,19 53,23\ub122,35 TP showed more attention on left interest area than on instructor area compared with NTP. On the same way TP showed a larger observations number on the left interest area compared with NTP. No significant differences were observed on the right and outline areas. CONCLUSIONS. Differences are not significant in condition \u201ca\u201d that can be assimilated to a general movement situation. In specific task as condition \u201cb\u201d was, training can improve perception and anticipation abilities especially in a complex task (left area, ball conducted by backhand) compared with a easy task (right area, forehand) (Smits-Engelsmann et al, 2006). NTP are tightly bind at easy perceptive task (e.g. to follow instructor figure). TP showed a higher ability in complex perceptive task (e.g. to follow ball trajectory). Further analyses and a larger sample is necessary to realize deeper studies about this subject. Bibliography. \u2022 Castiello U. e Umilt\ue0 C., 1988, \u201cAttenzione e tennis\u201d, SdS, nr. 7, pp 28-33 \u2022 Enns & Richards, 1997, \u201cVisual Attentional Orienting in Developing Hockey Players\u201d J.Experimental Child Psychology 64, 255-277 \u2022 Ferrel C., Bard C. e Fleury M., 2001, \u201cCoordination in childhood: modifications of visuomotor representations in 6 to 11 year old children\u201d, Experimental Brain Research, Jun; 138 (3):3 13-21, April. \u2022 Lambert J. e Bard C. (2005), \u201cAcquisition of visuomanual skills and improvement of information processing capacities in 6- to 10-year-old children performing a 2D pointing task\u201d, Neuroscience Letters, Volume 337, 22 March, pages. 1-6; \u2022 Ripoll H., 1988, \u201cAnalysis of Visual Scannig Patterns of Volleyball Players in a problem solving task\u201d, International Journal of Sport Psycology, n.19, pp. 9-25; \u2022 Smits-Engelsman, David Sugden e Jacques Duysens, 2006, \u201cDevelopmental trends in speed accuracy trade-off in 6\u201310-year-old children performing rapid reciprocal and discrete aiming movements\u201d, Human Movement Science, Volume 25, February, pages. 37 \u2013 49
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