OBJECTIVEThe synthesis, biodistribution, and animal imaging of 99mTc- hydrazinonicotinamide-folate (99mTc-HYNIC-Folate) were studied as a folate receptor-targeted tumor imaging agent.

METHODSHYNIC-Folate was synthesized by a muti-step reaction and radiolabeled with 99mTc using tricine and trisodium phenylphosphine-3, 3', 3"-trisulfonate (TPPTS) as coligands. The radiochemical purity and stability of 99mTc HYNIC-Folate was measured. The biodistributions of 99mTc-HYNIC-Folate in normal mice and tumor-bearing mice were detected. Whole-body gamma imaging was performed using an athymic mouse tumor xenograft model.

RESULTSThe ligand HYNIC-Folate was successfully synthesized and characterized by hydrogen nuclear magnetic resonance (1HNMR) and mass spectrometry (MS). The radiochemical purity of 99mTc-HYNIC-Folate was 96% under optimal conditions. Data from gamma scintigraphy and the biodistribution in tumor-bearing mice showed that 99mTc-HYNIC-Folate predominantly accumulated in tumor, its uptake rate per gram tissue alpham was 5. 620+/- 0. 753. The uptakes of 99mTc-HYNIC-Folate in the other non-target tissues were very low, except it was high in the kidneys ( am was 41. 959 +/-6. 759) .

CONCLUSION99mTc-HYNIC-Folate has the potential to be used as a noninvasive radiodiagnostic imaging agent for the detection of folate receptor-positive human cancers.

Animals ; Female ; Mice ; Mice, Inbred BALB C ; Mice, Inbred ICR ; Neoplasms, Experimental ; diagnostic imaging ; Organotechnetium Compounds ; chemical synthesis ; pharmacokinetics ; Radionuclide Imaging ; Radiopharmaceuticals ; chemical synthesis ; pharmacokinetics ; Tissue Distribution

BACKGROUNDScreening libraries against a molecular target in vitro are idealized models that cannot reflect the real state in vivo where biomolecules coexist and interact. C-terminal amide tripeptides labelled with Technetium-99m can provide a unique noninvasive approach to trace a large number of compounds in vivo.

METHODSThe C-terminal amide tripeptide libraries were synthesized on Rink Amide-MBHA resin using iterative and pooling protocol. Technetium (V) oxo core [TcO(3+)] was bound to each tripeptide via 4 deprotonated nitrogen atoms to form a library of 8000 (99m)Tc tripeptoid complexes. The radiocombinatorial screening (RCS) in vivo was carried out on SD rats and A549 tumour bearing mice.

RESULTSSignals of tissue distribution and metabolism of libraries were recorded by counting or imaging and tissue targeting leads identified by both random and directed RCS. Among them, (99m)Tc RPA, (99m)Tc VIG and (99m)Tc RES had specific tissue targeting in kidney, liver and tumour respectively. The percent injected dose per gram tissue of (99m)Tc labelled leads in their target tissue was highly structure dependent. Because the nontarget tissue binding and the metabolism of (99m)Tc tripeptoid sublibraries were simultaneously monitored successfully by RCS, the interference of background activity was limited to the lowest level. Optimization of renal function agent from the labelled libraries was carried out by directed screening. (99m)Tc DSG was finally identified the most promising agent for renal function studies.

CONCLUSIONSRCS in vivo is a powerful tool for the discovery of tissue targeting drugs. The potential screening bias is probably the major limitation of labelled libraries.

Animals ; Combinatorial Chemistry Techniques ; Drug Design ; Female ; Isotope Labeling ; Kidney Function Tests ; Liver ; diagnostic imaging ; Mice ; Mice, SCID ; Neoplasms, Experimental ; diagnostic imaging ; Peptide Library ; Radionuclide Imaging ; Radiopharmaceuticals ; chemical synthesis ; Rats ; Rats, Sprague-Dawley ; Technetium ; Tissue Distribution

In order to evaluate the biological activity in vitro and the antitumor effects of 131I-conditionally replicating oncolytic adenovirus KH901 on HepG2 human hepatoma xenografts, the leves of GM-CSF expression were determined by ELISA method. A panel of tumor and normal cells was infected with recombinant adenovirus KH901 at MOI of 10 PPC. The medium was harvested to determine the bioactivity of GM-CSF after 24 hours. Nude mice bearing HepG2 human hepatoma xenografts were given 131-KH901. Antitumor effects were assessed using endpoints of tumor growth delay. The data showed that after 24 hours 131-KH901 replicated hugely in tumor cells and produced significant amount of GM-CSF 183.27 +/- 6.90 pg/ml, while producing very small amount of GM-CSF 20.44 +/- 0.77 pg/ml in normal cells. In the treatment of tumor, 131I-KH901 showed higher restraint rate (71.3%) compared to 131I (22.7%) or KH901 (52.7%). Therefore, 131-KH901 can inhibit the growth of human hepatoma cell in nude mice and it may be a potential drug for treating liver cancer.
Adenoviridae ; genetics ; metabolism ; Animals ; Female ; Granulocyte-Macrophage Colony-Stimulating Factor ; genetics ; metabolism ; Hep G2 Cells ; Humans ; Iodine Radioisotopes ; Liver Neoplasms, Experimental ; diagnostic imaging ; pathology ; virology ; Male ; Mice ; Mice, Nude ; Oncolytic Virotherapy ; Oncolytic Viruses ; genetics ; metabolism ; Radionuclide Imaging

OBJECTIVE: We wanted to investigate the feasibility of using FDG-PET for evaluating the antitumor effect of intraarterial administration of a hexokinase II inhibitor, 3-bromopyruvate (3-BrPA), in a rabbit VX2 liver tumor model. MATERIALS AND METHODS: VX2 carcinoma was grown in the livers of ten rabbits. Two weeks later, liver CT was performed to confirm appropriate tumor growth for the experiment. After tumor volume-matched grouping of the rabbits, transcatheter intraarterial administration of 3-BrPA was performed (1 mM and 5 mM in five animals each, respectively). FDG-PET scan was performed the day before, immediately after and a week after 3-BrPA administration. FDG uptake was semiquantified by measuring the standardized uptake value (SUV). A week after treatment, the experimental animals were sacrificed and the necrosis rates of the tumors were calculated based on the histopathology. RESULTS: The SUV of the VX2 tumors before treatment (3.87+/-1.51[mean+/-SD]) was significantly higher than that of nontumorous liver parenchyma (1.72+/-0.34) (p < 0.0001, Mann-Whitney U test). The SUV was significantly decreased immediately after 3-BrPA administration (2.05+/-1.21) (p = 0.002, Wilcoxon signed rank test). On the one-week follow up PET scan, the FDG uptake remained significantly lower (SUV 1.41+/-0.73) than that before treatment (p = 0.002), although three out of ten animals showed a slightly increasing tendency for the FDG uptake. The tumor necrosis rate ranged from 50.00% to 99.90% (85.48%+/-15.87). There was no significant correlation between the SUV or the SUV decrease rate and the tumor necrosis rate in that range. CONCLUSION: Even though FDG-PET cannot exactly reflect the tumor necrosis rate, FDG-PET is a useful modality for the early assessment of the antitumor effect of intraarterial administration of 3-BrPA in VX2 liver tumor.
Animals ; Disease Models, Animal ; Enzyme Inhibitors/*pharmacology ; Feasibility Studies ; Fluorodeoxyglucose F18 ; Infusions, Intra-Arterial ; Injections, Intra-Arterial ; Liver Neoplasms, Experimental/*drug therapy/pathology/*radionuclide imaging ; Necrosis ; *Positron-Emission Tomography ; Pyruvate Dehydrogenase Complex/antagonists & inhibitors ; Pyruvates/*pharmacology ; Rabbits ; Radiopharmaceuticals

This paper was aimed to investigate the biodistribution and ability of free 131-bcl-2/bcl-xl ASON (FA) and anionic long circulation liposomes encapsulated with 131I-bcl-2/bcl-xlASON (NA), in tumor-bearing rats, to image breast cancer. We investigated the tissue distribution of NA in virgin female Sprague-Dawley (SD) rats with n-methyl nitrosourea (MNU)-induced breast cancers in situ. The percentage of the injected dose per gram (%ID/g) was calculated, with the maximum ratios of tumor to blood and tumor to muscle, after injections of NA and FA for 0.5 h, 1 h, 2 h, 3 h, 4 h, 6 h, 12 h and 24 h, respectively. The ability of NA to image breast cancer in tumor-bearing rats was determined using emission computed tomography (ECT). Seventy percent (90/130) SD rats in the study developed mammary tumors after MNU injection with the average latency (NA) (96 +/- 1.2)days. The %ID/g of NA in breast cancer tissue, tumor bearing rats in liver and spleen tumor tissues after 10 hours were (6.23 +/- 0.23) %ID/g, (12.00 +/- 0.26) %ID/g and (18.25 +/- 1.33)% ID/g, respectively. The ratios of tumor to blood 6.29 +/- 0.76 and tumor to muscle 10.55 +/- 0.68 in tumor bearing rats slowly maximized at 10 h post injection of NA, most probably due to the enhanced permeability and retention effect. Hence in radionuclide antisense scintigraphy, the breast cancer in rat was clearly displayed at 10h after iv administration of NA-D. However, tumors were not visualized in rats with the iv injection of NS and NN even at the delayed time. Due to the inhibition of rapid uptake of NA by the reticulo-endothelial system, NA displays valuable pharmacologic properties characterized by the enhanced accumulation in tumor.
Animals ; Female ; Iodine Radioisotopes ; Liposomes ; pharmacokinetics ; Mammary Neoplasms, Experimental ; metabolism ; Oligonucleotides, Antisense ; pharmacokinetics ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Radionuclide Imaging ; methods ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Tissue Distribution ; bcl-X Protein ; metabolism

Colloidal particle size is an important characteristic that allows mapping sentinel nodes in lymphoscintigraphy. This investigation aimed to introduce different ways of making a 99mTc-tin colloid with a size of tens of nanometers. All agents, tin fluoride, sodium fluoride, poloxamer-188, and polyvinylpyrrolidone (PVP), were mixed and labeled with 99mTc. Either phosphate or sodium bicarbonate buffers were used to adjust the pH levels. When the buffers were added, the size of the colloids increased. However, as the PVP continued to increase, the size of the colloids was controlled to within tens of nanometers. In all samples, phosphate buffer added PVP (30 mg) stabilized tin colloid (99mTc-PPTC-30) and sodium bicarbonate solution added PVP (50 mg) stabilized tin colloid (99mTc-BPTC-50) were chosen for in vitro and in vivo studies. 99mTc-BPTC-50 (<20 nm) was primarily located in bone marrow and was then secreted through the kidneys, and 99mTc-PPTC-30 (>100 nm) mainly accumulated in the liver. When a rabbit was given a toe injection, the node uptake of 99mTc-PPTC-30 decreased over time, while 99mTc-BPTC-50 increased. Therefore, 99mTc-BPTC-50 could be a good candidate radiopharmaceutical for sentinel node detection. The significance of this study is that nano-sized tin colloid can be made very easily and quickly by PVP.
Animals ; Buffers ; Cell Line, Tumor ; Humans ; Lymph Nodes/*radionuclide imaging ; Lymphatic Metastasis ; Metal Nanoparticles/chemistry/ultrastructure ; Mice ; Neoplasms, Experimental/*radionuclide imaging ; Particle Size ; Povidone/*chemistry ; Rabbits ; Radiopharmaceuticals/*chemical synthesis ; Reproducibility of Results ; Sensitivity and Specificity ; Technetium Compounds/*chemistry ; Tin/*chemistry ; Tin Compounds/*chemistry