Kallistatin Suppresses Cell Proliferation and Invasion and Promotes Apoptosis in Cervical Cancer Through Blocking NF-κB Signaling.

Kallistatin has been recognized as an endogenous angiogenesis inhibitor and exerts pleiotropic effects in inhibiting tumor growth, migration, apoptosis, and inflammation. The purpose of the present study was to investigate the potential role and mechanisms of kallistatin in cervical cancer. We demonstrated that kallistatin effectively inhibited cell proliferation and enhanced apoptosis in a dose-dependent manner.

A Randomized Controlled Trial Comparing Clinical Outcomes and Toxicity of Lobaplatin- Versus Cisplatin-Based Concurrent Chemotherapy Plus Radiotherapy and High-Dose-Rate Brachytherapy for FIGO Stage II and III Cervical Cancer.

Background: We designed this randomized controlled trial (RCT) to assess whether lobaplatin-based concurrent chemotherapy might be superior to cisplatin-based concurrent chemotherapy for FIGO stage II and III cervical cancer in terms of efficacy and safety.

Materials And Methods: This prospective, open-label RCT aims to enroll 180 patients with FIGO stage II and III cervical cancer, randomly allocated to one of the three treatment groups (cisplatin 15mg/m2, cisplatin 20mg/m2 and lobaplatin 35mg/m2), with 60 patients in each group. All patients will receive external beam irradiation (EBRT) and high-dose-rate intracavitary brachytherapy (HDR-ICBT).

Exendin-4 Enhances Motor Function Recovery via Promotion of Autophagy and Inhibition of Neuronal Apoptosis After Spinal Cord Injury in Rats.

Autophagy occurs prior to apoptosis and plays an important role in cell death regulation during spinal cord injury (SCI). This study aimed to determine the effects and potential mechanism of the glucagon-like peptide-1 (GLP-1) agonist extendin-4 (Ex-4) in SCI. Seventy-two male Sprague Dawley rats were randomly assigned to sham, SCI, 2.

Radiosynthesis of PET radiotracer as a prodrug for imaging group II metabotropic glutamate receptors in vivo.

Group II metabotropic glutamate receptors (mGluRs) have been implicated in a variety of neurological and psychiatric disorders in recent studies. As a noninvasive medical imaging technique and a powerful tool in neurological research, positron emission tomography (PET) offers the possibility to visualize and study group II mGluRs in vivo under physiologic and pathologic conditions. We synthesized a PET tracer, (S,S,S)-2-(2-carboxycyclopropyl)-2-(3-[(11)C]methoxyphenethyl) glycine dimethyl ester ([(11)C]CMGDE), as a prodrug for group II mGluRs, and studied its preliminary biological properties in Sprague-Dawley rats to visualize group II mGluRs.

Facile synthesis of new carbon-11 labeled conformationally restricted rivastigmine analogues as potential PET agents for imaging AChE and BChE enzymes.

Rivastigmine is a newer-generation inhibitor with a dual inhibitory action on both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes, and is used for the treatment of AChE- and BChE-related diseases such as brain Alzheimer's disease and cardiovascular disease. New carbon-11 labeled conformationally restricted rivastigmine analogues radiolabeled quaternary ammonium triflate salts, (3aR,9bS)-1-[(11)C]methyl-1-methyl-6-(methylcarbamoyloxy)-2,3,3a,4,5,9b-hexahydro-1H-benzo[g]indolium triflate ([(11)C]8) and (3aR,9bS)-1-[(11)C]methyl-1-methyl-6-(heptylcarbamoyloxy)-2,3,3a,4,5,9b-hexahydro-1H-benzo[g]indolium triflate ([(11)C]9), were designed and synthesized as potential positron emission tomography (PET) agents for imaging AChE and BChE enzymes. The appropriate precursors were labeled with [(11)C]CH(3)OTf through N-[(11)C]methylation, and the target tracers were isolated by solid-phase extraction (SPE) using a cation-exchange CM Sep-Pak cartridge in 40-50% radiochemical yields decay corrected to end of bombardment (EOB), 15-20 min overall synthesis time, and 148-222 GBq/micromol specific activity at EOB.

Evaluation of oasis ecosystem risk by reliability theory in an arid area: a case study in the Shiyang River Basin, China.

Ecosystem risk is a new concept in understanding environmental problems. It is important to study and develop quantitative methods for regional ecosystem risk analysis. In this study, some new indicators and methods for measuring oasis ecosystem risk were established using reliability theory.

Synthesis and preliminary biological evaluation of 3-[(18)F]fluoro-5-(2-pyridinylethynyl)benzonitrile as a PET radiotracer for imaging metabotropic glutamate receptor subtype 5.

The metabotropic glutamate receptor subtype 5 (mGluR5) has been reported to be implicated in various neurological disorders in the central nervous system. To investigate physiological and pathological functions of mGluR5, noninvasive imaging in a living body with PET technology and an mGluR5-specific radiotracer is urgently needed. Here, we report the synthesis of 3-[(18)F]fluoro-5-(2-pyridinylethynyl)benzonitrile ([(18)F]FPEB) through a convenient thermal reaction as a highly specific PET radiotracer for mGluR5.

Evaluation of four pyridine analogs to characterize 6-OHDA-induced modulation of mGluR5 function in rat brain using microPET studies.

Micro-positron emission tomography imaging studies were conducted to characterize modulation of metabotropic glutamate subtype-5 receptor (mGluR5) function in a 6-hydroxydopamine (6-OHDA)-induced rat model of Parkinson's disease using four analogical PET ligands: 2-[(11)C]methyl-6-(2-phenylethynyl) pyridine ([(11)C]MPEP), 2-(2-(3-[(11)C]methoxyphenyl)ethynyl)pyridine ([(11)C]M-MPEP), 2-(2-(5-[(11)C]methoxypyridin-3-yl)ethynyl)pyridine ([(11)C]M-PEPy), and 3-[(2-[(18)F]methyl-1,3-thiazol-4-yl)ethynyl]pyridine ([(18)F]M-TEP). A total of 45 positron emission tomography (PET) imaging studies were conducted on nine male Sprague-Dawley rats within 4 to 6 weeks after unilateral 6-OHDA lesioning into the right medial forebrain bundle. The severity of the lesion was determined with [(11)C]CFT ([(11)C]2-beta-carbomethoxy-3-beta-(4-fluorophenyl)tropane), a specific and sensitive ligand for imaging dopamine transporter function.

Synthesis of [11C]Iressa as a new potential PET cancer imaging agent for epidermal growth factor receptor tyrosine kinase.

Iressa (Gefitinib) is an orally active inhibitor of epidermal growth factor receptor tyrosine kinase (EGFR-TK) involved in cell signal transduction processes critical to proliferation, apoptosis, repair, and angiogenesis of cancer cells. [11C]Iressa was first designed and synthesized as a new potential positron emission tomography (PET) cancer imaging agent for EGFR-TK in 30-40% radiochemical yield with 4.0-6.

PET imaging and optical imaging with D-luciferin [11C]methyl ester and D-luciferin [11C]methyl ether of luciferase gene expression in tumor xenografts of living mice.

New carbon-11 labeled D-luciferin analogs D-luciferin [(11)C]methyl ester ([(11)C]LMEster, [(11)C]1) and D-luciferin [(11)C]methyl ether ([(11)C]LMEther, [(11)C]2) were synthesized in 25-55% radiochemical yield. PET studies with [(11)C]LMEster and [(11)C]LMEther demonstrate a lower retention of the C-11 label at 45 min post-injection in luciferase expression tumor. Optical imaging with unlabeled substrate D-luciferin and radiotracers [(11)C]LMEster and [(11)C]LMEther gave tumor luciferase images within a few minutes of photon counting.

Facile synthesis and PET imaging of a novel potential heart acetylcholinesterase tracer N-[11C]methyl-3-[[(dimethylamino)carbonyl]oxy]-2-(2',2'-diphenylpropionoxymethyl)pyridinium.

A new AChE tracer N-[(11)C]methyl-3-[[(dimethylamino)carbonyl]oxy]-2-(2',2'-diphenylpropionoxymethyl)pyridinium ([(11)C]MDDP, [(11)C]1) has been synthesized in 40-65% radiochemical yield. Initial PET dynamic studies of [(11)C]MDDP in rat heart showed rapid heart uptake and blood pool clearance to give high-quality heart images. Blocking studies of [(11)C]MDDP with pretreatment drug neostigmine in rats found only minor reductions in rat heart [(11)C]MDDP retention.

Synthesis of [18F]SU11248, a new potential PET tracer for imaging cancer tyrosine kinase.

N-[2-(Diethylamino)ethyl]-5-[(Z)-(5-[18F]fluoro-2-oxo-1,2-dihydro-3H-indol-3-ylidene)methyl]-2,4-dimethyl-1H-pyrrole-3-carboxamide, a new potential positron emission tomography tracer for imaging cancer tyrosine kinase, has been prepared by the nucleophilic substitution of the nitro-precursor N-[2-(diethylamino)ethyl]-5-[(Z)-(5-nitro-2-oxo-1,2-dihydro-3H-indol-3-ylidene)methyl]-2,4-dimethyl-1H-pyrrole-3-carboxamide with K18F/Kryptofix 2.2.2 followed by a simple chromatography methodology combined solid-phase extraction with high-performance liquid chromatography purification procedures in 15-25% radiochemical yields.

Synthesis and preliminary biological evaluation of O6-[4-(2-[18F]fluoroethoxymethyl)benzyl]guanine as a novel potential PET probe for the DNA repair protein O6-alkylguanine-DNA alkyltransferase in cancer chemotherapy.

A novel fluorine-18-labeled O6-benzylguanine (O6-BG) derivative, O6-[4-(2-[18F]fluoroethoxymethyl)benzyl]guanine (O6-[18F]FEMBG, [18F]1), has been synthesized for evaluation as a potential positron emission tomography (PET) probe for the DNA repair protein O6-alkylguanine-DNA alkyltransferase (AGT) in cancer chemotherapy. The appropriate radiolabeling precursor N(2,9)-bis(p-anisyldiphenylmethyl)-O6-[4-(hydroxymethyl)benzyl]guanine (6) and reference standard O6-[4-(2-fluoroethoxymethyl)benzyl]guanine (O6-FEMBG, 1) were synthesized from 1,4-benzenedimethanol and 2-amino-6-chloropurine in four or six steps, respectively, with moderate to excellent chemical yields. The target tracer O6-[18F]FEMBG was prepared in 20-35% radiochemical yields by reaction of MTr-protected precursor 6 with [18F]fluoroethyl bromide followed by quick deprotection reaction and purification with a simplified Silica Sep-Pak method.

Lipophilicity coefficients of potential tumor imaging agents, positron-labeled O(6)-benzylguanine derivatives.

Novel radiolabeled O(6)-benzylguanine (O(6)-BG) derivatives, 6-O-[(11)C]-[(methoxymethyl)benzyl]guanines ([(11)C]p-O(6)-MMBG, 1a; [(11)C]m-O(6)-MMBG, 1b; [(11)C]o-O(6)-MMBG, 1c), 2-amino-6-O-[(11)C]-[(methoxymethyl)benzyloxy]-9-methyl purines ([(11)C]p-O(6)-AMMP, 2a; [(11)C]m-O(6)-AMMP, 2b; [(11)C]o-O(6)-AMMP, 2c), 2-amino-6-O-[(11)C]-[(methoxymethyl)benzyloxy]-9-benzyl purines ([(11)C]p-O(6)-AMBP, 3a; [(11)C]m-O(6)-AMBP, 3b; [(11)C]o-O(6)-AMBP, 3c), 2-amino-6-O-benzyloxy-9-[(11)C]-[(methoxycarbonyl)methyl]purine ([(11)C]ABMMP, 4), and 2-amino-6-O-benzyloxy-9-[(11)C]-[(4'-methoxycarbonyl)benzyl]purine ([(11)C]ABMBP, 5), have been synthesized for evaluation as potential novel positron emission tomography tumor imaging agents. The ability of O(6)-BG analogs to penetrate the blood--brain barrier in brain tumor could be due, at least in part, to their lipophilicity. In this paper, we measured lipophilicity coefficients (log P) of compounds 1--5 by the C(18) HPLC method.

Synthesis of [18F]Xeloda as a novel potential PET radiotracer for imaging enzymes in cancers.

Xeloda (Capecitabine), a prodrug of antitumor agent 5-fluorouracil, is the first and only oral fluoropyrimidine to be approved for use as second-line therapy in metastatic breast cancer, colorectal cancer, and other solid malignancies. Fluorine-18 labeled Xeloda may serve as a novel radiotracer for positron emission tomography (PET) to image enzymes such as thymidine phosphorylase and uridine phosphorylase in cancers. The precursor 2',3'-di-O-acetyl-5'-deoxy-5-nitro-N(4)-(pentyloxycarbonyl)cytidine (11) was synthesized from D-ribose and cytosine in 8 steps with approximately 18% overall chemical yield.

Synthesis of 2-amino-6-(4-[11C]methoxyphenylthio)-9-[2-(phosphonomethoxy)ethyl]purine bis(2,2,2-trifluoroethyl) ester as a novel potential PET gene reporter probe for HBV and HSV-tk in cancers.

Acyclic nucleoside 2-amino-6-(4-methoxyphenylthio)-9-[2-(phosphonomethoxy)ethyl]purine bis(2,2,2-trifluoroethyl) ester (ABE, 1) is a new hepatitis B virus (HBV) specific antiviral reagent and shows high anti-HBV activity. Carbon-11 labeled ABE may serve as a novel reporter probe for positron emission tomography (PET) to image HBV and herpes simplex virus thymidine kinase (HSV-tk) in cancers. The radiolabeling precursors 2-amino-6-(4-hydroxyphenylthio)-9-[2-(phosphonomethoxy)ethyl]purine bis(2,2,2-trifluoroethyl) ester (10) and 2-N-Boc protected analogue 2-N-bis(Boc)amino-6-(4-hydroxyphenylthio)-9-[2-(phosphonomethoxy)ethyl]purine bis(2,2,2-trifluoroethyl) ester (12), and the reference standard ABE were synthesized from bis(trifluoroethyl) (2-iodoethoxy)methylphosphonate (5), guanine (6), and 2-amino-6-chloropurine (8).

Facile synthesis and initial PET imaging of novel potential heart acetylcholinesterase imaging agents [11C]pyridostigmine and its analogs.

A series of 11C-labeled analogs of the acetylcholinesterase (AChE) inhibitor pyridostigmine have been synthesized for evaluation as new potential positron emission tomography (PET) imaging agents for heart AChE. The appropriate precursors for radiolabeling were slightly modified from commercial reagents. The new tracers [11C]pyridostigmine (1), [11C]para-pyridostigmine (2) and [11C]ortho-pyridostigmine (3) were prepared by N-[11C]methylation of the precursors using [11C]methyl triflate.

[11C]Choline as a PET biomarker for assessment of prostate cancer tumor models.

[(11)C]Choline has been evaluated as a positron emission tomography (PET) biomarker for assessment of established human prostate cancer tumor models. [(11)C]Choline was prepared by the reaction of [(11)C]methyl triflate with 2-dimethylaminoethanol (DMAE) and isolated and purified by solid-phase extraction (SPE) method in 60-85% yield based on [(11)C]CO(2), 15-20 min overall synthesis time from end of bombardment (EOB), 95-99% radiochemical purity and specific activity >0.8 Ci/micromol at end of synthesis (EOS).

Synthesis, biodistribution and micro-PET imaging of radiolabeled antimitotic agent T138067 analogues.

Radiolabeled antimitotic agents [11C]T138067 and [18F]T138067 have been synthesized for evaluation as new potential positron emission tomography (PET) biomarkers for cancer imaging. In vivo biodistribution and micro-PET imaging of [11C]T138067 were performed in breast cancer animal models MCF-7 transfected with IL-1alpha implanted athymic mice and MDA-MB-435 implanted athymic mice. The results suggest that the uptakes of [11C]T138067 in both MCF-7 transfected with IL-1alpha tumor and MDA-MB-435 tumor are non-specific binding.

Comparative studies of potential cancer biomarkers carbon-11 labeled MMP inhibitors (S)-2-(4'-[11C]methoxybiphenyl-4-sulfonylamino)-3-methylbutyric acid and N-hydroxy-(R)-2-[[(4'-[11C]methoxyphenyl)sulfonyl]benzylamino]-3-methylbutanamide.

(S)-2-(4'-[11C]methoxybiphenyl-4-sulfonylamino)-3-methylbutyric acid ([11C]MSMA) and N-hydroxy-(R)-2-[[(4'-[11C]methoxyphenyl)sulfonyl]benzylamino]-3-methylbutanamide ([11C]CGS 25966), carbon-11 labeled matrix metalloproteinase (MMP) inhibitors, have been synthesized for evaluation as new potential positron emission tomography (PET) cancer biomarkers. [11C]MSMA was prepared by appropriate precursor (S)-2-(4'-hydroxybiphenyl-4-sulfonylamino)-3-methylbutyric acid tert-butyl ester, which was synthesized in eight steps from amino acid (L)-valine in 39.4% chemical yield.

Novel radiosynthesis of PET HSV-tk gene reporter probes [18F]FHPG and [18F]FHBG employing dual Sep-Pak SPE techniques.

Positron emission tomography (PET) herpes simplex virus thymidine kinase (HSV-tk) gene reporter probes 9-[(3-[(18)F]fluoro-1-hydroxy-2-propoxy)methyl]guanine ([(18)F]FHPG) and 9-(4-[(18)F]fluoro-3-hydroxymethylbutyl)guanine ([(18)F]FHBG) were prepared by nucleophilic substitution of the appropriate tosylated precursors with [(18)F]KF/Kryptofix 2.2.2 followed by a quick deprotection reaction and purification with a simplified dual Silica Sep-Pak solid-phase extraction (SPE) method in 15-30% radiochemical yield.

Synthesis, biodistribution and micro-PET imaging of a potential cancer biomarker carbon-11 labeled MMP inhibitor (2R)-2-[[4-(6-fluorohex-1-ynyl)phenyl]sulfonylamino]-3-methylbutyric acid [11C]methyl ester.

(2R)-2-[[4-(6-fluorohex-1-ynyl)phenyl]sulfonylamino]-3-methylbutyric acid [(11)C]methyl ester ([(11)C]FMAME), a novel carbon-11 labeled matrix metalloproteinase (MMP) inhibitor, has been synthesized for evaluation as new potential positron emission tomography (PET) cancer biomarker. [(11)C]FMAME was prepared by appropriate precursor (2R)-2-[[4-(6-fluorohex-1-ynyl)phenyl]sulfonylamino]-3-methylbutyric acid (FMA), which was synthesized in six steps from (D)-valine in 71% chemical yield. This acid precursor was labeled by [(11)C]methyl triflate through O-[(11)C]methylation method under basic conditions and isolated by solid-phase extraction (SPE) purification to produce pure target compound in 40-55% radiochemical yield, based on (11)CO(2), decay corrected to end of bombardment, and 15-20 min synthesis time.

Synthesis of radiolabeled biphenylsulfonamide matrix metalloproteinase inhibitors as new potential PET cancer imaging agents.

Novel matrix metalloproteinase (MMP) inhibitor radiotracers, (S)-3-methyl-2-(2',3',4'-methoxybiphenyl-4-sulfonylamino)-butyric acid [(11)C]methyl ester (1a-c), (S)-3-methyl-2-(2',3',4'-fluorobiphenyl-4-sulfonylamino)-butyric acid [(11)C]methyl ester (1d-f), and (S)-3-methyl-2-(4'-nitrobiphenyl-4-sulfonylamino)-butyric acid [(11)C]methyl ester (1g), a series of substituted biphenylsulfonamide derivatives, have been synthesized for evaluation as new potential positron emission tomography (PET) cancer imaging agents.