92 research outputs found

    Tumor cell-derived PDGF-B potentiates mouse mesenchymal stem cells-pericytes transition and recruitment through an interaction with NRP-1

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    <p>Abstract</p> <p>Background</p> <p>New blood vessel formation, or angiogenic switch, is an essential event in the development of solid tumors and their metastatic growth. Tumor blood vessel formation and remodeling is a complex and multi-step processes. The differentiation and recruitment of mural cells including vascular smooth muscle cells and pericytes are essential steps in tumor angiogenesis. However, the role of tumor cells in differentiation and recruitment of mural cells has not yet been fully elucidated. This study focuses on the role of human tumor cells in governing the differentiation of mouse mesenchymal stem cells (MSCs) to pericytes and their recruitment in the tumor angiogenesis process.</p> <p>Results</p> <p>We show that C3H/10T1/2 mouse embryonic mesenchymal stem cells, under the influence of different tumor cell-derived conditioned media, differentiate into mature pericytes. These differentiated pericytes, in turn, are recruited to bind with capillary-like networks formed by endothelial cells on the matrigel under <it>in vitro </it>conditions and recruited to bind with blood vessels on gel-foam under <it>in vivo </it>conditions. The degree of recruitment of pericytes into <it>in vitro </it>neo-angiogenesis is tumor cell phenotype specific. Interestingly, invasive cells recruit less pericytes as compared to non-invasive cells. We identified tumor cell-secreted platelet-derived growth factor-B (PDGF-B) as a crucial factor controlling the differentiation and recruitment processes through an interaction with neuropilin-1 (NRP-1) in mesenchymal stem cells.</p> <p>Conclusion</p> <p>These new insights into the roles of tumor cell-secreted PDGF-B-NRP-1 signaling in MSCs-fate determination may help to develop new antiangiogenic strategies to prevent the tumor growth and metastasis and result in more effective cancer therapies.</p

    Cyr61/CCN1 signaling is critical for epithelial-mesenchymal transition and stemness and promotes pancreatic carcinogenesis

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    <p>Abstract</p> <p>Background</p> <p>Despite recent advances in outlining the mechanisms involved in pancreatic carcinogenesis, precise molecular pathways and cellular lineage specification remains incompletely understood.</p> <p>Results</p> <p>We show here that Cyr61/CCN1 play a critical role in pancreatic carcinogenesis through the induction of EMT and stemness. Cyr61 mRNA and protein were detected in the early precursor lesions and their expression intensified with disease progression. Cyr61/CCN1 expression was also detected in different pancreatic cancer cell lines. The aggressive cell lines, in which the expressions of mesenchymal/stem cell molecular markers are predominant; exhibit more Cyr61/CCN1 expression. Cyr61 expression is exorbitantly higher in cancer stem/tumor initiating Panc-1-side-population (SP) cells. Upon Cyr61/CCN1 silencing, the aggressive behaviors are reduced by obliterating interlinking pathobiological events such as reversing the EMT, blocking the expression of stem-cell-like traits and inhibiting migration. In contrast, addition of Cyr61 protein in culture medium augments EMT and stemness features in relatively less aggressive BxPC3 pancreatic cancer cells. Using a xenograft model we demonstrated that cyr61/CCN1 silencing in Panc-1-SP cells reverses the stemness features and tumor initiating potency of these cells. Moreover, our results imply a miRNA-based mechanism for the regulation of aggressive behaviors of pancreatic cancer cells by Cyr61/CCN1.</p> <p>Conclusions</p> <p>In conclusion, the discovery of the involvement of Cyr61/CCN1 in pancreatic carcinogenesis may represent an important marker for PDAC and suggests Cyr61/CCN1 can be a potential cancer therapeutic target.</p

    Amorphous carbon film deposition on inner surface of tubes using atmospheric pressure pulsed filamentary plasma source

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    Uniform amorphous carbon film is deposited on the inner surface of quartz tube having the inner diameter of 6 mm and the outer diameter of 8 mm. A pulsed filamentary plasma source is used for the deposition. Long plasma filaments (~ 140 mm) as a positive discharge are generated inside the tube in argon with methane admixture. FTIR-ATR, XRD, SEM, LSM and XPS analyses give the conclusion that deposited film is amorphous composed of non-hydrogenated sp2 carbon and hydrogenated sp3 carbon. Plasma is characterized using optical emission spectroscopy, voltage-current measurement, microphotography and numerical simulation. On the basis of observed plasma parameters, the kinetics of the film deposition process is discussed

    Potential Role of Platelet-Derived Growth Factor Receptor Inhibition Using Imatinib in Combination with Docetaxel in the Treatment of Recurrent Non-small Cell Lung Cancer

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    Introduction:Platelet-derived growth factor receptor (PDGFR) is expressed in lung cancer and is involved in angiogenesis. Preclinical models demonstrated that imatinib (Im) regulates angiogenesis through PDGFR inhibition and enhances efficacy of chemotherapy. Hypothesis: We hypothesized that Im plus docetaxel (D) would have a synergistic effect detectable by an increase in response rate in patients with recurrent non-small cell lung cancer (NSCLC).Methods:A phase II trial to evaluate Im in combination with D in patients with recurrent NSCLC was conducted. The primary end point was response rate, using a Simon two-stage design. Eligible patients had measurable disease and no more than two chemotherapy regimens. D was given at 30 mg/m2/wk intravenously ×3 every 4 weeks and oral Im at 600 mg daily for four cycles. Patients required two cycles to be evaluable for response. Nonprogressors after four cycles continued with Im maintenance until progression or for a total of 12 months.Results:Twenty-three patients were enrolled in the first stage. Toxicity was mainly nonhematologic. We observed one partial response (5.5%), four stable disease (22.2%), and 13 progressed (72.2%). Median time to progression was 1.9 months, and median overall survival was 6.1 months. Two patients who went on Im maintenance had time to progression of 7.78 months and 15.8 months.Conclusion:Im in combination with D did not achieve its primary objective of improving response rate in patients with recurrent NSCLC. An increased understanding of the complex PDGFR pathway in lung cancer and alternative strategies to inhibit it are needed

    A Second Generation 2-Methoxyestradiol Prodrug Is Effective Against Barrett's Adenocarcinoma in a Mouse Xenograft Model

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    This is the author's accepted manuscript. The original is available at http://mct.aacrjournals.org/content/12/3/2552-Methoxyestradiol (2-ME2) is an endogenous metabolite of estradiol. In preclinical models, 2-ME2 is effective against different types of tumors. Unfortunately, only low systemic concentrations of 2-ME2 can be achieved following oral administration, even after very high doses are administered to patients. In an effort to solve this problem we have now synthesized and tested a new prodrug of 2-ME2 that is water soluble due to a bio-reversible hydrophilic group added at the 3-position and more effectively resists metabolic inactivation due to an ester moiety added to mask the 17-position alcohol. We are reporting here for the first time that this double prodrug of 2-ME2 is effective as an antiproliferative and anti-cancer agent for both in vitro and in vivo studies against Barrett's esophageal adenocarcinoma (BEAC), and provided greater potency than 2-ME2 in inhibiting the growth of BEAC xenografts. Finally, studies indicate that, like 2-ME2, the 2-ME2-PD1 exhibits anticancer effect through possible disruption of microtubule-network

    Treatment outcome of intravenous artesunate in patients with severe malaria in the Netherlands and Belgium

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    <p>Abstract</p> <p>Background</p> <p>Intravenous (IV) artesunate is the treatment of choice for severe malaria. In Europe, however, no GMP-manufactured product is available and treatment data in European travellers are scarce. Fortunately, artesunate became available in the Netherlands and Belgium through a named patient programme. This is the largest case series of artesunate treated patients with severe malaria in Europe.</p> <p>Methods</p> <p>Hospitalized patients treated with IV artesunate between November 2007 and December 2010 in the Netherlands and Belgium were retrospectively evaluated. Patient characteristics, treatment and clinical outcome were recorded on a standardized form and mortality, parasite clearance times and the occurrence of adverse events were evaluated.</p> <p>Results</p> <p>Of the 68 treated patients, including 55 with severe malaria, two patients died (2/55 = 3.6%). The mean time to 50% parasite clearance (PCT50), 90% and 99% were 4.4 hours (3.9 - 5.2), 14.8 hours (13.0 - 17.2), and 29.5 hours (25.9 - 34.4) respectively. Artesunate was well tolerated. However, an unusual form of haemolytic anaemia was observed in seven patients. The relationship with artesunate remains uncertain.</p> <p>Conclusions</p> <p>Data from the named patient programme demonstrate that IV artesunate is effective and well-tolerated in European travellers lacking immunity. However, increased attention needs to be paid to the possible development of haemolytic anaemia 2-3 weeks after start of treatment.</p> <p>Treatment of IV artesunate should be limited to the period that IV treatment is required and should be followed by a full oral course of an appropriate anti-malarial drug.</p

    Reproducibility of Standing Posture for X-Ray Radiography: A Feasibility Study of the BalancAid with Healthy Young Subjects

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    Unreliable spinal X-ray radiography measurement due to standing postural variability can be minimized by using positional supports. In this study, we introduce a balancing device, named BalancAid, to position the patients in a reproducible position during spinal X-ray radiography. This study aimed to investigate the performance of healthy young subjects’ standing posture on the BalancAid compared to standing on the ground mimicking the standard X-rays posture in producing a reproducible posture for the spinal X-ray radiography. A study on the posture reproducibility measurement was performed by taking photographs of 20 healthy young subjects with good balance control standing on the BalancAid and the ground repeatedly within two consecutive days. We analyzed nine posterior–anterior (PA) and three lateral (LA) angles between lines through body marks placed in the positions of T3, T7, T12, L4 of the spine to confirm any translocations and movements between the first and second day measurements. No body marks repositioning was performed to avoid any error. Lin’s CCC test on all angles comparing both standing postures demonstrated that seven out of nine angles in PA view, and two out of three angles in LA view gave better reproducibility for standing on the BalancAid compared to standing on the ground. The PA angles concordance is on average better than that of the LA angles
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