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Bolkestein M.,Laboratory of Experimental Surgical Oncology | De Blois E.,Erasmus University Rotterdam | Koelewijn S.J.,Erasmus University Rotterdam | Eggermont A.M.M.,Gustave Roussy Cancer Campus Grand Paris | And 3 more authors.
Journal of Nuclear Medicine

Liposomal chemotherapy offers several advantages over conventional therapies, including high intratumoral drug delivery, reduced side effects, prolonged circulation time, and the possibility to dose higher. The efficient delivery of liposomal chemotherapeutics relies, however, on the enhanced permeability and retention (EPR) effect, which refers to the ability of macromolecules to extravasate leaky tumor vessels and accumulate in the tumor tissue. Using a panel of human xenograft tumors, we evaluated the influence of the EPR effect on liposomal distribution in vivo by injection of pegylated liposomes radiolabeled with 111In. Liposomal accumulation in tumors and organs was followed over time by SPECT/CT imaging. We observed that fast-growing xenografts, which may be less representative of tumor development in patients, showed higher liposomal accumulation than slow-growing xenografts. Additionally, several other parameters known to influence the EPR effect were evaluated, such as blood and lymphatic vessel density, intratumoral hypoxia, and the presence of infiltrating macrophages. The investigation of various parameters showed a few correlations. Although hypoxia, proliferation, and macrophage presence were associated with tumor growth, no hard conclusions or predictions could be made regarding the EPR effect or liposomal uptake. However, liposomal uptake was significantly correlated with tumor growth, with fast-growing tumors showing a higher uptake, although no biological determinants could be elucidated to explain this correlation. COPYRIGHT © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc. Source

Saeed M.,Laboratory of Experimental Surgical Oncology | Van Brakel M.,Netherlands Cancer Institute | Zalba S.,Laboratory of Experimental Surgical Oncology | Schooten E.,Netherlands Cancer Institute | And 4 more authors.
International Journal of Nanomedicine

Therapy of melanoma using T-cells with genetically introduced T-cell receptors (TCRs) directed against a tumor-selective cancer testis antigen (CTA) NY-ESO1 demonstrated clear antitumor responses in patients without side effects. Here, we exploited the concept of TCR-mediated targeting through introduction of single-chain variable fragment (scFv) antibodies that mimic TCRs in binding major histocompatibility complex-restricted CTA. We produced scFv antibodies directed against Melanoma AntiGEn A1 (MAGE A1) presented by human leukocyte antigen A1 (HLA-A1), in short M1/A1, and coupled these TCR-like antibodies to liposomes to achieve specific melanoma targeting. Two anti-M1/A1 antibodies with different ligand-binding affinities were derived from a phage-display library and reformatted into scFvs with an added cysteine at their carboxyl termini. Protein production conditions, ie, bacterial strain, temperature, time, and compartments, were optimized, and following production, scFv proteins were purified by immobilized metal ion affinity chromatography. Batches of pure scFvs were validated for specific binding to M1/A1-positive B-cells by flow cytometry. Coupling of scFvs to liposomes was conducted by employing different conditions, and an optimized procedure was achieved. In vitro experiments with immunoliposomes demonstrated binding of M1/A1-positive B-cells as well as M1/A1-positive melanoma cells and internalization by these cells using flow cytometry and confocal microscopy. Notably, the scFv with nonenhanced affinity of M1/A1, but not the one with enhanced affinity, was exclusively bound to and internalized by melanoma tumor cells expressing M1/A1. Taken together, antigen-mediated targeting of tumor cells as well as promoting internalization of nanoparticles by these tumor cells is mediated by TCR-like scFv and can contribute to melanoma-specific targeting. © 2016 Saeed et al. Source

Van Der Zee J.A.,Laboratory of Experimental Surgical Oncology | Ten Hagen T.L.M.,Laboratory of Experimental Surgical Oncology | Hop W.C.J.,Erasmus Medical Center | Van Dekken H.,Erasmus Medical Center | And 5 more authors.
European Journal of Cancer

The high mortality rate and minimal progress made in the treatment of pancreatic cancer over the last few decades, warrant an alternative approach. Treatment protocols should be individualised to the patient guided by prognostic markers. A particularly interesting target would be the architectural transcription factor high mobility group A1 (HMGA1), that is low or undetectable in normal tissue, induced during neoplastic transformation and consequently often exceptionally high in cancer. The aim of the current study was therefore to determine the differential expression of HMGA1 in pancreatic head and periampullary cancer and investigate its relation with outcome. HMGA1 expression was determined by immunohistochemistry on original paraffin embedded tissue from 99 pancreatic head- and 112 periampullary cancers (with R0). Expression was investigated for associations with recurrence free (RFS), cancer specific (CSS) and overall survival (OS) and conventional prognostic factors. HMGA1 was expressed in 47% and 26% of pancreatic head- and periampullary cancer, respectively and associated with poor RFS, CSS and OS in periampullary cancer. CSS 5 years following surgery was 25% and 44% for patients with tumours which were positive or negative for HMGA1 protein, respectively. HMGA1 expression was not associated with survival in pancreatic head cancer. In conclusion HMGA1 was identified as an independent prognostic marker predicting poor outcome in periampullary cancer. Although expressed to a higher extent as compared to periampullary cancer, HMGA1 was not associated with survival in pancreatic head cancer. © 2010 Elsevier Ltd. All rights reserved. Source

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