Citation Details

Journal Article

MDA-MB-231-luc2, IVIS, Breast Cancer, Bioware, Angiogenesis Inhibitors/pharmacology; *Cell Communication/drug effects; Cell Proliferation/drug effects; Extracellular Matrix/drug effects/metabolism; Fibroblasts/drug effects/metabolism/pathology; Gene Silencing/drug effects; Human Umbilical Vein Endothelial Cells/drug effects/metabolism; Humans; Intercellular Signaling Peptides and Proteins/pharmacology; Luminescent Measurements; Matrix Metalloproteinase 14/metabolism; Microscopy, Fluorescence, Multiphoton; *Models, Biological; Neoplasms/*blood supply/enzymology/*pathology; Neovascularization, Pathologic/*pathology; Signal Transduction/drug effects; Spheroids, Cellular/drug effects/enzymology/pathology; Stromal Cells/drug effects/pathology; Tumor Cells, Cultured

Angiogenesis, the formation of new blood vessels, is an essential process for tumour progression and is an area of significant therapeutic interest. Different in vitro systems and more complex in vivo systems have been described for the study of tumour angiogenesis. However, there are few human 3D in vitro systems described to date which mimic the cellular heterogeneity and complexity of angiogenesis within the tumour microenvironment. In this study we describe the Minitumour model--a 3 dimensional human spheroid-based system consisting of endothelial cells and fibroblasts in co-culture with the breast cancer cell line MDA-MB-231, for the study of tumour angiogenesis in vitro. After implantation in collagen-I gels, Minitumour spheroids form quantifiable endothelial capillary-like structures. The endothelial cell pre-capillary sprouts are supported by the fibroblasts, which act as mural cells, and their growth is increased by the presence of cancer cells. Characterisation of the Minitumour model using small molecule inhibitors and inhibitory antibodies show that endothelial sprout formation is dependent on growth factors and cytokines known to be important for tumour angiogenesis. The model also shows a response to anti-angiogenic agents similar to previously described in vivo data. We demonstrate that independent manipulation of the different cell types is possible, using common molecular techniques, before incorporation into the model. This aspect of Minitumour spheroid analysis makes this model ideal for high content studies of gene function in individual cell types, allowing for the dissection of their roles in cell-cell interactions. Finally, using this technique, we were able to show the requirement of the metalloproteinase MT1-MMP in endothelial cells and fibroblasts, but not cancer cells, for sprouting angiogenesis.

Journal Article

SKOV3-luc-D3, SKOV3-luc, IVIS, Ovarian Cancer, Animals; Antineoplastic Agents, Phytogenic/*administration & dosage; Cell Line, Tumor; Drug Carriers/*chemical synthesis/chemistry/therapeutic use; Drug Delivery Systems/*methods; Female; Flow Cytometry; Humans; Integrin alpha Chains/metabolism; Mice; Mice, Nude; Micelles; Microscopy, Confocal; Nanoparticles/chemistry/therapeutic use; Ovarian Neoplasms/*drug therapy; Paclitaxel/*administration & dosage; Peptides/chemical synthesis/therapeutic use; Polyethylene Glycols/chemistry

Micellar nanoparticles based on linear polyethylene glycol (PEG) block dendritic cholic acids (CA) copolymers (telodendrimers), for the targeted delivery of chemotherapeutic drugs in the treatment of cancers, are reported. The micellar nanoparticles have been decorated with a high-affinity “OA02” peptide against alpha-3 integrin receptor to improve the tumor-targeting specificity which is overexpressed on the surface of ovarian cancer cells. “Click chemistry” was used to conjugate alkyne-containing OA02 peptide to the azide group at the distal terminus of the PEG chain in a representative PEG(5k)-CA(8) telodendrimer (micelle-forming unit). The conjugation of OA02 peptide had negligible influence on the physicochemical properties of PEG(5k)-CA(8) nanoparticles and as hypothesized, OA02 peptide dramatically enhanced the uptake efficiency of PEG(5k)-CA(8) nanoparticles (NP) in SKOV-3 and ES-2 ovarian cancer cells via receptor-mediated endocytosis, but not in alpha-3 integrin-negative K562 leukemia cells. When loaded with paclitaxel, OA02-NPs had significantly higher in vitro cytotoxicity against both SKOV-3 and ES-2 ovarian cancer cells as compared with nontargeted nanoparticles. Furthermore, the in vivo biodistribution study showed OA02 peptide greatly facilitated tumor localization and the intracellular uptake of PEG(5k)-CA(8) nanoparticles into ovarian cancer cells as validated in SKOV3-luc tumor-bearing mice. Finally, paclitaxel (PTX)-loaded OA02-NPs exhibited superior antitumor efficacy and lower systemic toxicity profile in nude mice bearing SKOV-3 tumor xenografts, when compared with equivalent doses of nontargeted PTX-NPs as well as clinical paclitaxel formulation (Taxol). Therefore, OA02-targeted telodendrimers loaded with paclitaxel have great potential as a new therapeutic approach for patients with ovarian cancer.

Journal Article

U-87 MG-luc2, U-87-MG-luc2, Glioma, Bioware, IVIS, Animals; Brachytherapy/*methods; Brain Neoplasms/pathology/*radiotherapy; Convection; Glioblastoma/pathology/*radiotherapy; Glioma/pathology/*radiotherapy; Liposomes; Nanoparticles/therapeutic use; Radioisotopes/*therapeutic use; Rats; Rhenium/*therapeutic use; Tumor Burden; Xenograft Model Antitumor Assays

Although external beam radiation is an essential component to the current standard treatment of primary brain tumors, its application is limited by toxicity at doses more than 80 Gy. Recent studies have suggested that brachytherapy with liposomally encapsulated radionuclides may be of benefit, and we have reported methods to markedly increase the specific activity of rhenium-186 ((186)Re)-liposomes. To better characterize the potential delivery, toxicity, and efficacy of the highly specific activity of (186)Re-liposomes, we evaluated their intracranial application by convection-enhanced delivery in an orthotopic U87 glioma rat model. After establishing an optimal volume of 25 microL, we observed focal activity confined to the site of injection over a 96-hour period. Doses of up to 1850 Gy were administered without overt clinical or microscopic evidence of toxicity. Animals treated with (186)Re-liposomes had a median survival of 126 days (95% confidence interval [CI], 78.4-173 days), compared with 49 days (95% CI, 44-53 days) for controls. Log-rank analysis between these 2 groups was highly significant (P = .0013) and was even higher when 100 Gy was used as a cutoff (P < .0001). Noninvasive luciferase imaging as a surrogate for tumor volume showed a statistically significant separation in bioluminescence by 11 days after 100 Gy or less treatment between the experimental group and the control animals (chi(2)[1, N= 19] = 4.8; P = .029). MRI also supported this difference in tumor size. Duplication of tumor volume differences and survival benefit was possible in a more invasive U251 orthotopic model, with clear separation in bioluminescence at 6 days after treatment (chi(2)[1, N= 9] = 4.7; P = .029); median survival in treated animals was not reached at 120 days because lack of mortality, and log-rank analysis of survival was highly significant (P = .0057). Analysis of tumors by histology revealed minimal areas of necrosis and gliosis. These results support the potential efficacy of the highly specific activity of brachytherapy by (186)Re-liposomes convection-enhanced delivery in glioma.

Journal Article

IntegriSense, Animals; Cell Line, Tumor; Diagnostic Imaging/*methods; Fluorescent Dyes/chemistry/metabolism; Humans; Mice; Molecular Probes/*diagnostic use; Nanoparticles/chemistry; Quantum Dots; Spectroscopy, Near-Infrared/*methods

Cellular and tissue imaging in the near-infrared (NIR) wavelengths between 700 and 900 nm is advantageous for in vivo imaging because of the low absorption of biological molecules in this region. This unit presents protocols for small animal imaging using planar and fluorescence lifetime imaging techniques. Included is an overview of NIR fluorescence imaging of cells and small animals using NIR organic fluorophores, nanoparticles, and multimodal imaging probes. The development, advantages, and application of NIR fluorescent probes that have been used for in vivo imaging are also summarized. The use of NIR agents in conjunction with visible dyes and considerations in selecting imaging agents are discussed. We conclude with practical considerations for the use of these dyes in cell and small animal imaging applications.

Journal Article

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BACKGROUND: Lung cancer is the leading cause of cancer-related death in the United States, with more than half of the cancers are located peripherally. Computed tomography (CT) has been utilized in the last decade to detect early peripheral lung cancer. However, due to the high false diagnosis rate of CT, further biopsy is often necessary to confirm cancerous cases. This renders intervention for peripheral lung nodules (especially for small peripheral lung cancer) difficult and time-consuming, and it is highly desirable to develop new, on-the-spot earlier lung cancer diagnosis and treatment strategies. PURPOSE: The objective of this study is to develop a minimally invasive multimodality image-guided (MIMIG) intervention system to detect lesions, confirm small peripheral lung cancer, and potentially guide on-the-spot treatment at an early stage. Accurate image guidance and real-time optical imaging of nodules are thus the key techniques to be explored in this work. METHODS: The MIMIG system uses CT images and electromagnetic (EM) tracking to help interventional radiologists target the lesion efficiently. After targeting the lesion, a fiber-optic probe coupled with optical molecular imaging contrast agents is used to confirm the existence of cancerous tissues on-site at microscopic resolution. Using the software developed, pulmonary vessels, airways, and nodules can be segmented and visualized for surgical planning; the segmented results are then transformed onto the intra-procedural CT for interventional guidance using EM tracking. Endomicroscopy through a fiber-optic probe is then performed to visualize tumor tissues. Experiments using IntegriSense 680 fluorescent contrast agent labeling alphavbeta3 integrin were carried out for rabbit lung cancer models. Confirmed cancers could then be treated on-the-spot using radio-frequency ablation (RFA). RESULTS: The prototype system is evaluated using the rabbit VX2 lung cancer model to evaluate the targeting accuracy, guidance efficiency, and performance of molecular imaging. Using this system, we achieved an average targeting accuracy of 3.04 mm, and the IntegriSense signals within the VX2 tumors were found to be at least two-fold higher than those of normal tissues. The results demonstrate great potential for applying the system in human trials in the future if an optical molecular imaging agent is approved by the Food and Drug Administration (FDA). CONCLUSIONS: The MIMIG system was developed for on-the-spot interventional diagnosis of peripheral lung tumors by combining image-guidance and molecular imaging. The system can be potentially applied to human trials on diagnosing and treating earlier stage lung cancer. For current clinical applications, where a biopsy is unavoidable, the MIMIG system without contrast agents could be used for biopsy guidance to improve the accuracy and efficiency.