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Ran, C.; Zhang, Z.; Hooker, J.; Moore, A.
In vivo photoactivation without "light": use of Cherenkov radiation to overcome the penetration limit of light
Mol Imaging Biol
MDA-MB-231-D3H1, MDA-MB-231-luc-D3H1, IVIS, Bioware, Breast Cancer. Animals; Cell Line, Tumor; Chromatography, Liquid; Diagnostic Imaging/*methods; *Elementary Particles; Firefly Luciferin/chemistry/metabolism; Fluorodeoxyglucose F18/diagnostic use; Humans; *Light; Luminescent Measurements; Mass Spectrometry; Mice; Mice, Nude; Solutions
PURPOSE: The poor tissue penetration of visible light has been a major barrier for optical imaging, photoactivatable conversions, and photodynamic therapy for in vivo targets with depths beyond 10 mm. In this report, as a proof-of-concept, we demonstrated that a positron emission tomography (PET) radiotracer, 2-deoxy-2-[(18)F]fluoro-D-glucose ((18)FDG), could be used as an alternative light source for photoactivation. PROCEDURES: We utilized (18)FDG, which is a metabolic activity-based PET probe, as a source of light to photoactivate caged luciferin in a breast cancer animal model expressing luciferase. RESULTS: Bioluminescence produced from luciferin allowed for the real-time monitoring of Cherenkov radiation-promoted uncaging of the substrate. CONCLUSION: The proposed method may provide a very important option for in vivo photoactivation, in particular for activation of photosensitizers for photodynamic therapy and eventually for combining radioisotope therapy and photodynamic therapy.
Korotcov, A. V.; Ye, Y.; Chen, Y.; Zhang, F.; Huang, S.; Lin, S.; Sridhar, R.; Achilefu, S.; Wang, P. C.
Glucosamine-linked near-infrared fluorescent probes for imaging of solid tumor xenografts
PC-3M-luc-C6, PC-3M-luc, IVIS, Bioware, Prostate cancer, Bioluminescence, Animals; Cell Line, Tumor; Endocytosis; Fluorescent Dyes/chemistry/*diagnostic use; Glucosamine/chemistry/*diagnostic use; Humans; Kinetics; Male; Mice; Mice, Nude; Molecular Imaging/*methods; Neoplasms/*diagnosis/pathology; Optical Devices; Prostatic Neoplasms/diagnosis/pathology; Spectroscopy, Near-Infrared; Tissue Distribution; *Xenograft Model Antitumor Assays
PURPOSE: Near-infrared fluorescence (NIRF) imaging is an attractive technique for studying diseases at the molecular level in vivo. Glucose transporters are often used as targets for in vivo imaging of tumors. The efficiency of a tumor-seeking fluorescent probe can be enhanced by attaching one or more glucosamine (GlcN) moieties. This study was designed to evaluate the use of previously developed GlcN-linked NIRF probes for in vitro and in vivo optical imaging of cancer. PROCEDURES: Cellular uptake of the probes (1 muM) was investigated in monolayer cultures of luciferase-expressing PC3 (PC3-luc) cells. The prostate tumors were established as subcutaneous xenografts using PC3-luc cells in nude mice. The biodistributions and tumor-targeting specificities of cypate (cyp), cypate-D: -(+)-glucosamine (cyp-GlcN), and D: -(+)-gluosamine-cypate-D: -(+)-gluosamine (cyp-2GlcN) were studied. The tumor, muscle, and major organs were collected for ex vivo optical imaging. RESULTS: The tumor cell uptake of the probe containing two glucosamine residues, cyp-2GlcN, was significantly higher than the uptake of both the probe with one glucosamine residue, cyp-GlcN, and the probe without glucosamine, cyp only. Similarly, in in vivo experiments, cyp-2GlcN demonstrated higher maximum fluorescence intensity and longer residence lifetime in tumors than cyp-GlcN or cyp. The ex vivo biodistribution analysis revealed that tumor uptake of cyp-2GlcN and cyp-GlcN was four- and twofold higher than that of cyp at 24 h post-injection, respectively. CONCLUSION: Both cyp-GlcN and cyp-2GlcN NIRF probes exhibited good tumor-targeting properties in prostate cancer cell cultures and live mice. The cyp-2GlcN probe showed the highest uptake with good retention characteristics in vivo. The uptake of cyp-2GlcN and cyp-GlcN is likely mediated by glucosamine-recognizing transporters. The uptake mechanism is being explored further for developing cypate-glucosamine-based probes for in vivo imaging.
Kadurugamuwa, J. L.; Modi, K.; Yu, J.; Francis, K. P.; Orihuela, C.; Tuomanen, E.; Purchio, A. F.; Contag, P. R.
Noninvasive monitoring of pneumococcal meningitis and evaluation of treatment efficacy in an experimental mouse model
Mol Imaging
Animals, Diagnostic Imaging, Disease Models, Animal, Female, Luminescent Measurements/methods, Meningitis, Pneumococcal/drug therapy/microbiology/ radiography, Mice, Mice, Inbred BALB C, Streptococcus pneumoniae/drug effects IVIS, Xenogen, Xen10
Noninvasive real-time in vivo bioluminescent imaging was used to assess the spread of Streptococcus pneumoniae throughout the spinal cord and brain during the acute stages of bacterial meningitis. A mouse model was established by lumbar (LP) or intracisternal (IC) injection of bioluminescent S. pneumoniae into the subarachnoid space. Bacteria replicated initially at the site of inoculation and spread progressively from the spinal cord to the brain or from the brain down to the cervical part of the spinal column and to the lower vertebral levels. After 24 hr, animals showed strong bioluminescent signals throughout the spinal canal, indicating acute meningitis of the intracranial and intraspinal meninges. A decline in bacterial cell viability, as judged by a reduction in the bioluminescent signal, was observed over time in animals treated with ceftriaxone, but not in untreated groups. Mice treated with the antibiotic survived infection, whereas all mice in untreated groups became moribund, first in the IC group then in the LP group. No untreated animal survived beyond 48 hr after induction of infection. Colony counts of infected cerebrospinal fluid (CSF) correlated positively with bioluminescent signals. This methodology is especially appealing because it allows detecting infected mice as early as 3 hr after inoculation, provide temporal, sequential, and spatial distribution of bacteria within the brain and spinal cord throughout the entire disease process and the rapid monitoring of treatment efficacy in a nondestructive manner. Moreover, it avoids the need to sacrifice the animals for CSF sampling and the potential manipulative damage that can occur with other conventional methods.
Ru, P.; Steele, R.; Newhall, P.; Phillips, N. J.; Toth, K.; Ray, R. B.
miRNA-29b suppresses prostate cancer metastasis by regulating epithelial-mesenchymal transition signaling
Mol Cancer Ther
PC-3M-luc-C6, PC-3M-luc, IVIS, Bioware, Prostate cancer, Bioluminescence
Prostate cancer remains the second leading cause of cancer deaths among American men. Early diagnosis increases survival rate in patients; however, treatments for advanced disease are limited to hormone ablation techniques and palliative care. Thus, new methods of treatment are necessary for inhibiting prostate cancer disease progression. Here, we have shown that miRNA-29b (miR-29b) expression was lower in prostate cancer cells (PC3 and LNCaP) as compared with immortalized prostate epithelial cells. Between these two prostate cancer cell lines, metastatic prostate cancer PC3 cells displayed lower expression of miR-29b. We also observed a significant downregulation of miR-29b expression in human prostate cancer tissues as compared with patient-matched nontumor tissues. PC3 cells ectopically expressing miR-29b inhibited wound healing, invasiveness, and failed to colonize in the lungs and liver of severe combined immunodeficient mice after intravenous injection, while PC3 cells expressing a control miRNA displayed metastasis. Epithelial cell marker E-cadherin expression was enhanced miR-29b transfected in prostate cancer cells as compared with cells expressing control miRNA. On the other hand, N-cadherin, Twist, and Snail expression was downregulated in PC3 cells expressing miR-29b. Together these results suggested that miR-29b acts as an antimetastatic miRNA for prostate cancer cells at multiple steps in a metastatic cascade. Therefore, miR-29b could be a potentially new attractive target for therapeutic intervention in prostate cancer.
Zuluaga, M. F.; Sekkat, N.; Gabriel, D.; van den Bergh, H.; Lange, N.
Selective Photodetection and Photodynamic Therapy of Prostate Cancer through Targeting of Proteolytic Activity
Frequent side effects of radical treatment modalities and the availability of novel diagnostics have raised the interest in focal therapies for localized prostate cancer. To improve the selectivity and therapeutic efficacy of such therapies, we developed a minimally invasive procedure, based on a novel polymeric photosensitizer prodrug sensitive to urokinase-like plasminogen activator (uPA). The compound is inactive in its prodrug form and accumulates passively at the tumor site by the enhanced permeability and retention effect. There, the prodrug is selectively converted to its photoactive form by uPA which is over-expressed by prostate cancer cells. Irradiation of the activated photosensitizer exerts a tumor-selective phototoxic effect. The prodrug alone (8 microM) showed no toxic effect on PC-3 cells, but upon irradiation the cell viability was reduced by 90%. In vivo, after systemic administration of the prodrug, PC-3 xenografts became selectively fluorescent. This is indicative of the prodrug accumulation in the tumor and selective local enzymatic activation. Qualitative analysis of the activated compound confirmed that the enzymatic cleavage occurred selectively in the tumor, with only trace amounts in the neighboring skin or muscle. Subsequent photodynamic therapy studies demonstrated complete tumor eradication of animals treated with light (150 J/cm2 at 665 nm) 16 hours after the injection of the prodrug (7.5 mg/kg). These promising results evidence the excellent selectivity of our prodrug with the potential to be used for both, imaging and therapy of localized prostate cancer.
Seo, G. M.; Rachakatla, R. S.; Balivada, S.; Pyle, M.; Shrestha, T. B.; Basel, M. T.; Myers, C.; Wang, H.; Tamura, M.; Bossmann, S. H.; Troyer, D. L.
A self-contained enzyme activating prodrug cytotherapy for preclinical melanoma
Mol Biol Rep
Animals, B16-F10-luc2, B16F10-luc2
Gene-directed enzyme prodrug therapy (GDEPT) has been investigated as a means of cancer treatment without affecting normal tissues. This system is based on the delivery of a suicide gene, a gene encoding an enzyme which is able to convert its substrate from non-toxic prodrug to cytotoxin. In this experiment, we have developed a targeted suicide gene therapeutic system that is completely contained within tumor-tropic cells and have tested this system for melanoma therapy in a preclinical model. First, we established double stable RAW264.7 monocyte/macrophage-like cells (Mo/Ma) containing a Tet-On(R) Advanced system for intracellular carboxylesterase (InCE) expression. Second, we loaded a prodrug into the delivery cells, double stable Mo/Ma. Third, we activated the enzyme system to convert the prodrug, irinotecan, to the cytotoxin, SN-38. Our double stable Mo/Ma homed to the lung melanomas after 1 day and successfully delivered the prodrug-activating enzyme/prodrug package to the tumors. We observed that our system significantly reduced tumor weights and numbers as targeted tumor therapy after activation of the InCE. Therefore, we propose that this system may be a useful targeted melanoma therapy system for pulmonary metastatic tumors with minimal side effects, particularly if it is combined with other treatments.
Emmett, M. S.; Lanati, S.; Dunn, D. B.; Stone, O. A.; Bates, D. O.
CCR7 mediates directed growth of melanomas towards lymphatics
IVIS, B16-F10-luc-G5, B16F10-luc-G5, B16-F10-luc, B16F10-luc,
OBJECTIVE: To determine whether chemotactic-metastasis, the preferential growth of melanomas towards areas of high lymphatic density, is CCL21/CCR7 dependent in vivo. Lymphatic endothelial cells (LECs) produce the chemokine CCL21. Metastatic melanoma cells express CCR7, its receptor, and exhibit chemotactic-metastasis, whereby metastatic cells recognise and grow towards areas of higher lymphatic density. METHODS: We used two in vivo models of directional growth towards depots of LECs of melanoma cells over-expressing CCR7. Injected LEC were tracked by intravital fluorescence microscopy, and melanoma growth by bioluminescence. RESULTS: Over-expression of the chemokine receptor CCR7 enables non-metastatic tumor cells to recognise and grow towards LECs (3.9 fold compared with control), but not blood endothelial cells (0.9 fold), in vitro and in vivo in the absence of increased lymphatic clearance. Chemotactic metastasis was inhibited by a CCL21 neutralising antibody (4-17% of control). Furthermore, CCR7 expression in mouse B16 melanomas resulted in in-transit metastasis (50-100% of mice) that was less often seen with control tumors (0-50%) in vivo. CONCLUSION: These results suggest that recognition of LEC by tumors expressing receptors for lymphatic specific ligands contributes towards the identification and invasion of lymphatics by melanoma cells and provides further evidence for a chemotactic metastasis model of tumor spread.
Balibar, Carl J; Shen, Xiaoyu; McGuire, Dorothy; Yu, Donghui; McKenney, David; Tao, Jianshi
cwrA, a gene that specifically responds to cell wall damage in Staphylococcus aureus
Microbiology (Reading, England)
Bioware bacteria
Pt 5
Animals; Anti-Bacterial Agents; Bacterial Proteins; Bacteriolysis; Bioware; Cell Wall; Gene Expression Profiling; Gene Knockout Techniques; Genes, Reporter; Lysostaphin; Mice; Microbial Sensitivity Tests; Sepsis; Staphylococcus aureus; Virulence; Xen29
Transcriptional profiling data accumulated in recent years for the clinically relevant pathogen Staphylococcus aureus have established a cell wall stress stimulon, which comprises a coordinately regulated set of genes that are upregulated in response to blockage of cell wall biogenesis. In particular, the expression of cwrA (SA2343, N315 notation), which encodes a putative 63 amino acid polypeptide of unknown biological function, increases over 100-fold in response to cell wall inhibition. Herein, we seek to understand the biological role that this gene plays in S. aureus. cwrA was found to be robustly induced by all cell wall-targeting antibiotics tested – vancomycin, oxacillin, penicillin G, phosphomycin, imipenem, hymeglusin and bacitracin – but not by antibiotics with other mechanisms of action, including ciprofloxacin, erythromycin, chloramphenicol, triclosan, rifampicin, novobiocin and carbonyl cyanide 3-chlorophenylhydrazone. Although a DeltacwrA S. aureus strain had no appreciable shift in MICs for cell wall-targeting antibiotics, the knockout was shown to have reduced cell wall integrity in a variety of other assays. Additionally, the gene was shown to be important for virulence in a mouse sepsis model of infection.
The alternative sigma factor sigma B of Staphylococcus aureus modulates virulence in experimental central venous catheter-related infections
Microbes and infection / Institut Pasteur
Animals; Bacterial Proteins; Biofilms; Bioware; Catheterization, Central Venous; Male; Mice; Point Mutation; Sigma Factor; Staphylococcal Infections; Staphylococcus aureus; Virulence; Xen29
The impact of the alternative sigma factor sigma B (SigB) on pathogenesis of Staphylococcus aureus is not conclusively clarified. In this study, a central venous catheter (CVC) related model of multiorgan infection was used to investigate the role of SigB for the pathogenesis of S. aureus infections and biofilm formation in vivo. Analysis of two SigB-positive wild-type strains and their isogenic mutants revealed uniformly that the wild-type was significantly more virulent than the SigB-deficient mutant. The observed difference in virulence was apparently not linked to the capability of the strains to form biofilms in vivo since wild-type and mutant strains were able to produce biofilm layers inside of the catheter. The data strongly indicate that the alternative sigma factor SigB plays a role in CVC-associated infections caused by S. aureus.
Sadikot, R. T.; Blackwell, T. S.
Bioluminescence: imaging modality for in vitro and in vivo gene expression
Methods Mol Biol
Adenoviridae/genetics, Anesthesia, Animals, Firefly Luciferin/administration & dosage/pharmacology, *Gene Expression Regulation/drug effects, Genetic Vectors/genetics, Luciferases/metabolism, Luminescent Measurements/*methods, Mice, Photons, Whole Body Imaging/*methods IVIS, Xenogen, Xen5
Molecular imaging offers many unique opportunities to study biological processes in intact organisms. Bioluminescence is the emission of light from biochemical reactions that occur within a living organism. Luciferase has been used as a reporter gene in transgenic mice but, until bioluminescence imaging was described, the detection of luciferase activity required either sectioning of the animal or excision of tissue and homogenization to measure enzyme activities in a conventional luminometer. Bioluminescence imaging (BLI) is based on the idea that biological light sources can be incorporated into cells and animal models artificially that does not naturally express the luminescent genes. This imaging modality has proven to be a very powerful methodology to detect luciferase reporter activity in intact animal models. This form of optical imaging is low cost and noninvasive and facilitates real-time analysis of disease processes at the molecular level in living organisms. Bioluminescence provides a noninvasive method to monitor gene expression in vivo and has enormous potential to elucidate the pathobiology of lung diseases in intact mouse models, including models of inflammation/injury, infection, and cancer.