Tumor-specific fluorescent imaging agents are moving towards the clinic, supporting surgeons with real-time intraoperative feedback about tumor locations. The epithelial cell adhesion molecule ... Show moreTumor-specific fluorescent imaging agents are moving towards the clinic, supporting surgeons with real-time intraoperative feedback about tumor locations. The epithelial cell adhesion molecule (EpCAM) is considered as one of the most promising tumor-specific proteins due its high overexpression on epithelial-derived cancers. This study describes the development and evaluation of EpCAM-F800, a novel fluorescent anti-EpCAM antibody fragment, for intraoperative tumor imaging. Fab production, conjugation to the fluorophore IRDye 800CW, and binding capacities were determined and validated using HPLC, spectrophotometry and cell-based assays. In vivo, dose escalation-, blocking-, pharmacokinetic- and biodistribution studies (using both fluorescence and radioactivity) were performed, next to imaging of clinically relevant orthotopic xenografts for breast and colorectal cancer. EpCAM-F800 targets EpCAM with high specificity in vitro, which was validated using in vivo blocking experiments with a 10x higher dose of unlabeled Fab. The optimal dose range for fluorescence tumor detection in mice was 1-5 nmol (52-260 mu g), which corresponds to a human equivalent dose of 0.2-0.8 mg/kg. Biodistribution showed high accumulation of EpCAM-F800 in tumors and metabolizing organs. Breast and colorectal tumors could clearly be visualized within 8h post-injection and up to 96 h, while the agent already showed homogenous tumor distribution within 4 h. The blood half-life was 4.5 h. This study describes the development and evaluation of a novel EpCAM-targeting agent and the feasibility to visualize breast and colorectal tumors by fluorescence imaging during resections. EpCAM-F800 will be translated for clinical use, considering its abundance in a broad range of tumor types. Show less
We aimed at investigating the role of 14q32 microRNAs in intimal hyperplasia and accelerated atherosclerosis; two major contributors to restenosis. Restenosis occurs regularly in patients treated... Show moreWe aimed at investigating the role of 14q32 microRNAs in intimal hyperplasia and accelerated atherosclerosis; two major contributors to restenosis. Restenosis occurs regularly in patients treated for coronary artery disease and peripheral arterial disease. We have previously shown that inhibition of 14q32 microRNAs leads to increased post-ischemic neovascularization, and microRNA miR-494 also decreased atherosclerosis, while increasing plaque stability. We hypothesized that 14q32microRNA inhibition has beneficial effects on intimal hyperplasia, as well as accelerated atherosclerosis.Non-constrictive cuffs were placed around both femoral arteries of C57BL/6J mice to induce intimal hyperplasia. Accelerated atherosclerotic plaque formation was induced in hypercholesterolemic ApoE mice by placing semi-constrictive collars around both carotid arteries. 14q32 microRNAs miR-329, miR-494 and miR-495 were inhibited in vivo using Gene Silencing Oligonucleotides (GSOs). GSO-495 administration led to a 32% reduction of intimal hyperplasia. Moreover, the number of macrophages in the arterial wall of mice treated with GSO-495 was reduced by 55%. Inhibition of miR-329 and miR-494 had less profound effects on intimal hyperplasia. GSO-495 administration also decreased atherosclerotic plaque formation by 52% and plaques of GSO-495 treated animals showed a more stable phenotype. Finally, cholesterol levels were also decreased in GSO-495 treated animals, via reduction of the VLDL-fraction. GSO-495 administration decreased our primary outcomes, namely intimal hyperplasia, and accelerated atherosclerosis. GSO-495 administration also favourably affected multiple secondary outcomes, including macrophage in flux, plaque stability and total plasma cholesterol levels. We conclude that 14q32 microRNA miR-495 is a promising target for prevention of restenosis. Show less
Gutowski, M.; Framery, B.; Boonstra, M.C.; Garambois, V.; Quenet, F.; Dumas, K.; ... ; Pelegrin, A. 2017
Fluorescence-guided surgery (FGS) is an intraoperative imaging technique already introduced and validated in the clinic for sentinel lymph node mapping and biliary imaging. Conjugating a NIR... Show moreFluorescence-guided surgery (FGS) is an intraoperative imaging technique already introduced and validated in the clinic for sentinel lymph node mapping and biliary imaging. Conjugating a NIR-dye to a specific tumor-targeting vehicle dramatically enhances the specificity of this technique. Hence, a powerful synergy can be achieved when fluorescent imaging is combined with nuclear imaging. The (NIR) fluorescent signal aids the surgeon to accurately recognize and resect malignant tissues and detect (nearby) vital structures in real-time during surgery, while its nuclear counterpart can be used to preoperative assess tumor spread and aid in the surgical planning and guidance. Patients may benefit directly from better tumor detection as the surgical status (R0 or R1) is one of the most import parameters for morbidity and patient survival. This thesis focus on the evaluation of potential targets for image-guided surgery applications and describes the preclinical evaluation of novel tracers for (hybrid) image-guided surgery. Show less
CONCLUSION: This study shows successful use of ICG: Nanocoll as lymphatic tracer for SLN detection in gastric cancer. Moreover, tumor-containing LNs outside the standard dissection planes were... Show moreCONCLUSION: This study shows successful use of ICG: Nanocoll as lymphatic tracer for SLN detection in gastric cancer. Moreover, tumor-containing LNs outside the standard dissection planes were identified. Show less
OBJECTIVES\nUnstable atherosclerotic lesions in carotid arteries require surgical endarterectomy to reduce the risk of ischemic stroke. We aimed to identify microRNAs that exert a broad effect on... Show moreOBJECTIVES\nUnstable atherosclerotic lesions in carotid arteries require surgical endarterectomy to reduce the risk of ischemic stroke. We aimed to identify microRNAs that exert a broad effect on atherosclerotic plaque formation and stability in the carotid artery.\nBACKGROUND\nWe made a selection of 164 genes involved in atherosclerosis. Using www.targetscan.org, we determined which microRNAs potentially regulate expression of these genes. We identified multiple microRNAs from the 14q32 microRNA cluster, which is highly involved in vascular remodeling. In human plaques, collected during carotid endarterectomy surgery, we found that 14q32 microRNA (miR-494) was abundantly expressed in unstable lesions.\nMETHODS\nWe induced atherosclerotic plaque formation in hypercholesterolemic ApoE mice by placing semiconstrictive collars around both carotid arteries. We injected "Gene Silencing Oligonucleotides" against miR-494 (GSO-494) or negative control (GSO-control). Using fluorescently labeled GSOs, we confirmed uptake of GSOs in affected areas of the carotids, but not elsewhere in the vasculature.\nRESULTS\nAfter injection of GSO-494, we observed significant downregulation of miR-494 expression in the carotid arteries, although miR-494 target genes were upregulated. Further analyses revealed a 65% decrease in plaque size after GSO-494 treatment. Plaque stability was increased in GSO-494-treated mice, determined by an 80% decrease in necrotic core size and a 50% increase in plaque collagen content. Inhibition of miR-494 also resulted in decreased cholesterol levels and decreased very low-density lipoprotein (VLDL) fractions.\nCONCLUSIONS\nTreatment with GSO-494 results in smaller atherosclerotic lesions with increased plaque stability. Inhibition of miR-494 may decrease the risk of surgical complications or even avert endarterectomy surgery in some cases. Show less
