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1.  Preclinical Efficacy of the c-Met Inhibitor CE-355621 in a U87 MG Mouse Xenograft Model Evaluated by 18F-FDG Small-Animal PET 
The purpose of this study was to evaluate the efficacy of CE-355621, a novel antibody against c-Met, in a subcutaneous U87 MG xenograft mouse model using 18F-FDG small-animal PET.
CE-355621 or control vehicle was administered intraperitoneally into nude mice (drug-treated group, n = 12; control group, n = 14) with U87 MG subcutaneous tumor xenografts. Drug efficacy was evaluated over 2 wk using 18F-FDG small-animal PET and compared with tumor volume growth curves.
The maximum %ID/g (percentage injected dose per gram of tissue) of 18F-FDG accumulation in mice treated with CE-355621 remained essentially unchanged over 2 wk, whereas the %ID/g of the control tumors increased 66% compared with the baseline. Significant inhibition of 18F-FDG accumulation was seen 3 d after drug treatment, which was earlier than the inhibition of tumor volume growth seen at 7 d after drug treatment.
CE-355621 is an efficacious novel antineoplastic chemotherapeutic agent that inhibits 18F-FDG accumulation earlier than tumor volume changes in a mouse xenograft model. These results support the use of 18F-FDG PET to assess early tumor response for CE-355621.
PMCID: PMC4161137  PMID: 18077531
CE-355621; c-Met inhibitor; 18F-FDG; microPET; drug evaluation; therapy response
2.  Non-Invasive Detection of Therapeutic Cytolytic T Cells with [18F]FHBG Positron Emission Tomography in a Glioma Patient 
A 57 years old male had been diagnosed with grade III/IV glioblastoma multiforme. The patient had then enrolled in an adoptive cellular immunotherapy trial. The trial involved infusion of ex vivo expanded autologous cytolytic CD8+ T cells (CTLs), genetically engineered to express the interleukin-13 zetakine gene (therapeutic gene, encoding a receptor protein that targets the T cells to the tumor cells), and the Herpes Simplex virus 1 thymidine kinase (HSV1-tk) suicide gene/positron emission tomography (PET) imaging reporter gene.
Whole-body and brain PET scan with 9-[4-[18F]Fluoro-3-(hydroxymethyl)butyl]guanine ([18F]FHBG) to detect HSV1-tk expressing CTLs, and safety monitoring following injection of [18F]FHBG.
Magnetic resonance imaging detection of grade III/IV glioblastoma multiforme plus recurrence of two tumors after resection of the initial tumor.
Surgical resection of original glioblastoma tumor, enrollment in CTL therapy trial, re-resection of glioma recurrence, infusion of approximately 1 X 109 CTL into the site of tumor re-resection, and [18F]FHBG PET scan to detect infused CTLs.
PMCID: PMC3526373  PMID: 19015650
3.  Positron Emission Tomography Reporter Genes and Reporter Probes: Gene and Cell Therapy Applications 
Theranostics  2012;2(4):374-391.
Positron emission tomography (PET) imaging reporter genes (IRGs) and PET reporter probes (PRPs) are amongst the most valuable tools for gene and cell therapy. PET IRGs/PRPs can be used to non-invasively monitor all aspects of the kinetics of therapeutic transgenes and cells in all types of living mammals. This technology is generalizable and can allow long-term kinetics monitoring. In gene therapy, PET IRGs/PRPs can be used for whole-body imaging of therapeutic transgene expression, monitoring variations in the magnitude of transgene expression over time. In cell or cellular gene therapy, PET IRGs/PRPs can be used for whole-body monitoring of therapeutic cell locations, quantity at all locations, survival and proliferation over time and also possibly changes in characteristics or function over time. In this review, we have classified PET IRGs/PRPs into two groups based on the source from which they were derived: human or non-human. This classification addresses the important concern of potential immunogenicity in humans, which is important for expansion of PET IRG imaging in clinical trials. We have then discussed the application of this technology in gene/cell therapy and described its use in these fields, including a summary of using PET IRGs/PRPs in gene and cell therapy clinical trials. This review concludes with a discussion of the future direction of PET IRGs/PRPs and recommends cell and gene therapists collaborate with molecular imaging experts early in their investigations to choose a PET IRG/PRP system suitable for progression into clinical trials.
PMCID: PMC3326723  PMID: 22509201
Positron Emission Tomography; PET Imaging Reporter Genes; Therapeutic Transgenes; Genetically Modified Therapeutic Cells; Imaging Therapeutic Transgenes or Cells
4.  A Novel Method for Direct site-specific Radiolabeling of Peptides Using [18F]FDG 
Bioconjugate chemistry  2009;20(3):432-436.
We have used the well-accepted and easily available 2-[18F]Fluoro-2-deoxyglucose ([18F]FDG) positron emission tomography (PET) tracer as a prosthetic group for synthesis of 18F-labeled peptides. We herein report the synthesis of [18F]FDG-RGD (18F labeled linear RGD) and [18F]FDG-cyclo(RGDDYK) (18F labeled cyclic RGD) as examples of the use of [18F]FDG. We have successfully prepared [18F]FDG-RGD and [18F]FDG-cyclo(RGDDYK) in 27.5% and 41% radiochemical yields (decay corrected) respectively. The receptor binding affinity study of FDG-cyclo(RGDDYK) for integrin αvβ3 , using αvβ3 positive U87MG cells confirmed a competitive displacement with 125I-echistatin as a radioligand. The IC50 value for FDG-cyclo(RGDDYK) was determined to be 0.67 ± 0.19µM. High contrast small animal PET images with relatively moderate tumor uptake were observed for [18F]FDG-RGD and [18F]FDG-cyclo(RGDDYK) as PET probes in xenografts models expressing αvβ3 integrin. In conclusion, we have successfully used [18F]FDG as a prosthetic group to prepare 18F]FDG-RGD and [18F]FDG-cyclic[RGDDYK] based on a simple one step radiosynthesis. The one step radiosynthesis methodology consists of chemoselective oxime formation between an aminooxy functionalized peptide and [18F]FDG. The results have implications for radiolabeling of other macromolecules and would lead to a very simple strategy for routine pre-clinical and clinical use.
PMCID: PMC2765576  PMID: 19226160
5.  Tissue-targeted therapy of autoimmune diabetes using dendritic cells transduced to express IL-4 in NOD mice 
Clinical immunology (Orlando, Fla.)  2008;127(2):176-187.
A deficit in IL-4 production has been previously reported in both diabetic human patients and non-obese diabetic (NOD) mice. In addition, re-introducing IL-4 into NOD mice systemically, or as a transgene, led to a beneficial outcome in most studies. Here, we show that prediabetic, 12-wk old female NOD mice have a deficit in IL-4 expression in the pancreatic lymph nodes (PLN) compared to age-matched diabetes-resistant NOD.B10 mice. By bioluminescence imaging, we demonstrated that the PLN was preferentially targeted by bone marrow-derived dendritic cells (DCs) following intravenous (IV) administration. Following IV injection of DCs transduced to express IL-4 (DC/IL-4) into 12-wk old NOD mice, it was possible to significantly delay or prevent the onset of hyperglycemia. We then focused on the PLN to monitor, by microarray analysis, changes in gene expression induced by DC/IL-4 and observed a rapid normalization of the expression of many genes, that were otherwise under-expressed compared to NOD.B10 PLN. The protective effect of DC/IL-4 required both MHC and IL-4 expression by the DCs. Thus, adoptive cellular therapy, using DCs modified to express IL-4, offers an effective, tissue-targeted cellular therapy to prevent diabetes in NOD mice at an advanced stage of pre-diabetes, and may offer a safe approach to consider for treatment of high risk human pre-diabetic patients.
PMCID: PMC2453076  PMID: 18337172

Results 1-5 (5)