bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synergistic effects of methylnaltrexone with 5-fluorouracil and bevacizumab on inhibition of vascular endothelial growth factor–induced angiogenesis
Authors: Singleton Patrick A. , Garcia Joe G.N. , Moss Jonathan 
Published: June 2008

Abstract
Many patients with cancer receive combinations of drug treatments that include 5-fluorouracil (5-FU) and bevacizumab. Therapeutic doses of 5-FU are often associated with unwanted side effects, and bevacizumab is costly. Therefore, we explored potential agents that can reduce the therapeutic concentration of these drugs. Our data indicate that methylnaltrexone (MNTX), a peripheral antagonist of the μ-opioid receptor, exerts a synergistic effect with 5-FU and bevacizumab on inhibition of vascular endothelial growth factor (VEGF)–induced human pulmonary microvascular endothelial cell (EC) proliferation and migration, two key components in cancer-associated angiogenesis. MNTX inhibited EC proliferation with an IC50 of ∼100 nmol/L. Adding 100 nmol/L MNTX to EC shifted the IC50 of 5-FU from ∼5 μmol/L to ∼7 nmol/L. Further, adding 50 ng/mL MNTX shifted the IC50 of bevacizumab on inhibition of EC migration from ∼25 to ∼6 ng/mL. These synergistic effects were not observed with naltrexone, a tertiary μ-opioid receptor antagonist. On a mechanistic level, we observed that treatment of human EC with MNTX, but not naltrexone, increased receptor protein tyrosine phosphatase μ activity, which was independent of μ-opioid receptor expression. Silencing receptor protein tyrosine phosphatase μ expression (small interfering RNA) in human EC inhibited both synergy between MNTX and bevacizumab or 5-FU and increased VEGF-induced tyrosine phosphorylation of Src and p190 RhoGAP with enhanced activation of Akt and the actin cytoskeletal regulatory protein, RhoA, whereas silencing Src, Akt, or RhoA blocked VEGF-induced angiogenic events. Therefore, addition of MNTX could potentially lower the therapeutic doses of 5-FU and bevacizumab, which could improve index. [Mol Cancer Ther 2008;7(6):1669–79]
Intrinsically lower AKT, mammalian target of rapamycin, and hypoxia-inducible factor activity correlates with increased sensitivity to 2-deoxy-d-glucose under hypoxia in lung cancer cell lines
Authors: Wangpaichitr Medhi , Savaraj Niramol , Maher Johnathan , Kurtoglu Metin , Lampidis Theodore J. 
Published: June 2008

Abstract
Down-regulation by small interfering RNA or absence of hypoxia-inducible factor (HIF-1α) has been shown to lead to increased sensitivity to glycolytic inhibitors in hypoxic tumor cells. In surveying a number of tumor types for differences in intrinsic levels of HIF under hypoxia, we find that the reduction of the upstream pathways of HIF, AKT, and mammalian target of rapamycin (mTOR) correlates with increased toxic effects of 2-deoxy-d-glucose (2-DG) in lung cancer cell lines when treated under hypoxia. Because HIF-1α translation is regulated by mTOR, we examined the effects of blocking mTOR under hypoxia with an analogue of rapamycin (CCI-779) in those cell lines that showed increased mTOR and AKT activity and found that HIF-1α down-regulation coincided with increased 2-DG killing. CCI-779, however, was ineffective in increasing 2-DG toxicity in cell lines that did not express HIF. These results support the hypothesis that although mTOR inhibition leads to the blockage of numerous downstream targets, CCI-779 increases the toxicity of 2-DG in hypoxic cells through down-regulation of HIF-1α. Overall, our findings show that CCI-779 hypersensitizes hypoxic tumor cells to 2-DG and suggests that the intrinsic expression of AKT, mTOR, and HIF in lung cancer, as well as other tumor types, may be important in dictating the decision on how best to use 2-DG alone or in combination with CCI-799 to kill hypoxic tumor cells clinically. [Mol Cancer Ther 2008;7(6):1506–13]
In vitro and in vivo targeting of hollow gold nanoshells directed at epidermal growth factor receptor for photothermal ablation therapy
Authors: Melancon Marites P. , Lu Wei , Yang Zhi , Zhang Rui , Cheng Zhi , Elliot Andrew M. , Stafford Jason , Olson Tammy , Zhang Jin Z. , Li Chun 
Published: June 2008

Abstract
Laser-induced phototherapy is a new therapeutic use of electromagnetic radiation for cancer treatment. The use of targeted plasmonic gold nanoparticles can reduce the laser energy necessary for selective tumor cell destruction. However, the ability for targeted delivery of the currently used gold nanoparticles to tumor cells is limited. Here, we describe a new class of molecular specific photothermal coupling agents based on hollow gold nanoshells (HAuNS; average diameter, ∼30 nm) covalently attached to monoclonal antibody directed at epidermal growth factor receptor (EGFR). The resulting anti-EGFR-HAuNS exhibited excellent colloidal stability and efficient photothermal effect in the near-infrared region. EGFR-mediated selective uptake of anti-EGFR-HAuNS in EGFR-positive A431 tumor cells but not IgG-HAuNS control was shown in vitro by imaging scattered light from the nanoshells. Irradiation of A431 cells treated with anti-EGFR-HAuNS with near-infrared laser resulted in selective destruction of these cells. In contrast, cells treated with anti-EGFR-HAuNS alone, laser alone, or IgG-HAuNS plus laser did not show observable effect on cell viability. Using 111In-labeled HAuNS, we showed that anti-EGFR-HAuNS could be delivered to EGFR-positive tumors at 6.8% ID/g, and the microscopic image of excised tumor with scattering signal from nanoshells confirmed preferential delivery to A431 tumor of anti-EGFR-HAuNS compared with IgG-HAuNS. The absence of silica core, the relatively small particle size and high tumor uptake, and the absence of cytotoxic surfactant required to stabilize other gold nanoparticles suggest that immuno-HAuNS have the potential to extend to in vivo molecular therapy. [Mol Cancer Ther 2008;7(6):1730–9]
5-Aminolaevulinic acid peptide prodrugs enhance photosensitization for photodynamic therapy
Authors: Bourré Ludovic , Giuntini Francesca , Eggleston Ian M. , Wilson Michael , MacRobert Alexander J. 
Published: June 2008

AbstractIntracellular porphyrin generation following administration of 5-aminolaevulinic acid (ALA) has been widely used in photodynamic therapy for a range of malignant and nonmalignant lesions. However, ALA is relatively hydrophilic and lacks stability at physiologic pH, limiting its bioavailability. We have investigated more lipophilic, uncharged ALA-peptide prodrugs based on phenylalanyl-ALA conjugates, which are water soluble and chemically stable for improving ALA delivery. Pharmacokinetics of the induced protoporphyrin IX (PpIX) were studied in transformed PAM212 keratinocyte cells and pig skin explants. The intracellular porphyrin production was substantially increased with Ac-l-Phe-ALA-Me (compound 1) and Ac-l-Phe-ALA (compound 3) compared with equimolar ALA: after 6-h incubation, the PpIX fluorescence measured using 0.01 mmol/L of compound 1 was enhanced by a factor of 5 compared with ALA. Phototoxicity results showed good correlation with PpIX levels, giving a LD50 (2.5 J/cm2) of 25 μmol/L for ALA, 6 μmol/L for 5-aminolaevulinic hexyl ester, and 2.6 μmol/L for compound 1, which exhibited the highest phototoxicity. However, these results were stereospecific because the corresponding d-enantiomer, Ac-d-Phe-ALA-Me (compound 2), induced neither porphyrin synthesis nor phototoxicity. PpIX levels were considerably reduced when cells were incubated with compound 1 at low temperatures, consistent with active transport. In pig skin explants, compound 1 induced higher porphyrin fluorescence than ALA by a factor of 3. These results show that water-soluble peptide prodrugs of ALA can greatly increase its cellular uptake, generating more intracellular PpIX and improved tumor cell photosensitization. The derivatives are comparable in efficacy with 5-aminolaevulinic hexyl ester but less toxic and more stable at physiologic pH. [Mol Cancer Ther 2008;7(6):1720–9]
Significant antitumor activity in vivo following treatment with the microtubule agent ENMD-1198
Authors: LaVallee Theresa M. , Burke Patricia A. , Swartz Glenn M. , Hamel Ernest , Agoston Gregory E. , Shah Jamshed , Suwandi Lita , Hanson Art D. , Fogler William E. , Sidor Carolyn F. , Treston Anthony M. 
Published: June 2008

Abstract
Clinical studies using the microtubule-targeting agent 2-methoxyestradiol (2ME2; Panzem) in cancer patients show that treatment is associated with clinical benefit, including prolonged stable disease, complete and partial responses, and an excellent safety profile. Studies have shown that 2ME2 is metabolized by conjugation at positions 3 and 17 and oxidation at position 17. To define structure-activity relationships for these positions of 2ME2 and to generate metabolically stable analogues with improved anti-tubulin properties, a series of analogues was generated and three lead analogues were selected, ENMD-1198, ENMD-1200, and ENMD-1237. These molecules showed improved metabolic stability with &gt;65% remaining after 2-h incubation with hepatocytes. Pharmacokinetic studies showed that oral administration of the compounds resulted in increased plasma levels compared with 2ME2. All three analogues bind the colchicine binding site of tubulin, induce G2-M cell cycle arrest and apoptosis, and reduce hypoxia-inducible factor-1α levels. ENMD-1198 and ENMD-1200 showed improved in vitro antiproliferative activities. Significant reductions in tumor volumes compared with vehicle-treated mice were observed in an orthotopic breast carcinoma (MDA-MB-231) xenograft model following daily oral treatment with all compounds (ANOVA, P &lt; 0.05). Significantly improved median survival time was observed with ENMD-1198 and ENMD-1237 (200 mg/kg/d) in a Lewis lung carcinoma metastatic model (P &lt; 0.05). In both tumor models, the high-dose group of ENMD-1198 showed antitumor activity equivalent to that of cyclophosphamide. ENMD-1198 was selected as the lead molecule in this analogue series and is currently in a phase I clinical trial in patients with refractory solid tumors. [Mol Cancer Ther 2008;7(6):1472–82]
Reactivation of p53 by a specific MDM2 antagonist (MI-43) leads to p21-mediated cell cycle arrest and selective cell death in colon cancer
Authors: Shangary Sanjeev , Ding Ke , Qiu Su , Nikolovska-Coleska Zaneta , Bauer Joshua A. , Liu Meilan , Wang Guoping , Lu Yipin , McEachern Donna , Bernard Denzil , Bradford Carol R. , Carey Thomas E. , Wang Shaomeng 
Published: June 2008

Abstract
MDM2 oncoprotein binds directly to the p53 tumor suppressor and inhibits its function in cancers retaining wild-type p53. Blocking this interaction using small molecules is a promising approach to reactivate p53 function and is being pursued as a new anticancer strategy. The spiro-oxindole MI-43, a small-molecule inhibitor of the MDM2-p53 interaction, was designed and examined for its cellular mechanism of action and therapeutic potential in colon cancer. MI-43 binds to MDM2 protein with a Ki value of 18 nmol/L and is 300 times more potent than a native p53 peptide. MI-43 blocks the intracellular MDM2-p53 interaction and induces p53 accumulation in both normal and cancer cells, with wild-type p53 without causing p53 phosphorylation. Induction of p53 leads to modulation of the expression of p53 target genes, including up-regulation of p21 and MDM2 in normal primary human cells and in colon cancer cells with wild-type p53. Using HCT-116 isogenic colon cancer cell lines differing only in p53 status or RNA interference to knockdown expression of p53 in the RKO colon cancer cell line, we show that the cell growth inhibition and cell death induction by MI-43 is p53 dependent. Furthermore, induction of cell cycle arrest by MI-43 is dependent on p53 and p21. In normal cells, MI-43 induces cell cycle arrest but not apoptosis. This study suggests that p53 activation by a potent and specific spiro-oxindole MDM2 antagonist may represent a promising therapeutic strategy for the treatment of colon cancer and should be further evaluated in vivo and in the clinic. [Mol Cancer Ther 2008;7(6):1533–42]
Evaluation of a chemical library of small-molecule Dishevelled antagonists that suppress tumor growth by down-regulating T-cell factor–mediated transcription
Authors: You Liang , Xu Zhidong , Punchihewa Chandanamali , Jablons David M. , Fujii Naoaki 
Published: June 2008

Abstract
We describe the rational generation of small-molecule agents that suppress tumor cell growth by down-regulating canonical Wnt signaling. We first produced a chemical library of the derivatives of indole-2-ketones and carbinols; we then screened them by using scalable assays of biochemical antagonism of Dishevelled-1 PDZ domain interactions and cell-based assays of Dishevelled-1–driven T-cell factor–mediated transcription. Compounds showing parallel effects in these assays were tested for selective induction of apoptosis in cancer cells. A new compound (24) that met the criteria for high biochemical antagonism, T-cell factor–mediated transcription, and induction of tumor-selective apoptosis was found to significantly suppress the growth of tumor xenografts in mice. [Mol Cancer Ther 2008;7(6):1633–8]
Molecular mechanisms of the antiangiogenic and antitumor effects of mycophenolic acid
Authors: Domhan Sophie , Muschal Stefan , Schwager Christian , Morath Christian , Wirkner Ute , Ansorge Wilhelm , Maercker Christian , Zeier Martin , Huber Peter E. , Abdollahi Amir 
Published: June 2008

Abstract
The relative risk for the development of malignancies following solid organ transplantation seems to be decreased in patients treated with the immunosuppressive agent mycophenolic acid (MPA). However, the molecular mechanisms of the antineoplastic effects of MPA are not completely understood. Here, we report that human endothelial cells and fibroblasts are highly sensitive to MPA treatment. We found that U87 glioblastoma cells were resistant to MPA treatment in vitro. However, U87 tumor growth was markedly inhibited in vivo in BALB/c nude mice, suggesting that MPA exerted its antitumor effects via modulation of the tumor microenvironment. Accordingly, microvascular density and pericyte coverage were markedly reduced in MPA-treated tumors in vivo. Using functional in vitro assays, we showed that MPA potently inhibited endothelial cell and fibroblast proliferation, invasion/migration, and endothelial cell tube formation. To identify the genetic participants governing the antiangiogenic and antifibrotic effects of MPA, we performed genome-wide transcriptional analysis in U87, endothelial and fibroblast cells at 6 and 12 h after MPA treatment. Network analysis revealed a critical role for MYC signaling in endothelial cells treated with MPA. Moreover, we found that the antiangiogenic effects of MPA were organized by coordinated communications between MYC and NDRG1, YYI, HIF1A, HDAC2, CDC2, GSK3B, and PRKACB signaling. The regulation of these “hub nodes” was confirmed by real-time quantitative reverse transcription-PCR and protein analysis. The critical involvement of MYC in the antiangiogenic signaling of MPA was further shown by gene knockdown experiments. Together, these data provide a molecular basis for the antiangiogenic and antifibrotic effects of MPA, which warrants further clinical investigations. [Mol Cancer Ther 2008;7(6):1656–68]
Nonlinear Amygdala Response to Face Trustworthiness: Contributions of High and Low Spatial Frequency Information
Authors: Said Christopher P. , Baron Sean G. , Todorov Alexander 
Published: June 2008

AbstractPrevious neuroimaging research has shown amygdala sensitivity to the perceived trustworthiness of neutral faces, with greater responses to untrustworthy compared with trustworthy faces. This observation is consistent with the common view that the amygdala encodes fear and is preferentially responsive to negative stimuli. However, some studies have shown greater amygdala activation to positive compared with neutral stimuli. The first goal of this study was to more fully characterize the amygdala response to face trustworthiness by modeling its activation with both linear and nonlinear predictors. Using fMRI, we report a nonmonotonic response profile, such that the amygdala responds strongest to highly trustworthy and highly untrustworthy faces. This finding complicates future attempts to make inferences about mental states based on activation in the amygdala. The second goal of the study was to test for modulatory effects of image spatial frequency filtering on the amygdala response. We predicted greater amygdala sensitivity to face trustworthiness for low spatial frequency images compared with high spatial frequency images. Instead, we found that both frequency ranges provided sufficient information for the amygdala to differentiate faces on trustworthiness. This finding is consistent with behavioral results and suggests that trustworthiness information may reach the amygdala through pathways carrying both coarse and fine resolution visual signals.
Current and former ecstasy users report different sleep to matched controls: a web-based questionnaire study
Authors: Carhart-Harris RL , Nutt DJ , Munafò M , Wilson SJ 
Published: June 2008

Abstract This study sought to test the association between ecstasy-use and abnormal sleep. An anonymous web-based questionnaire containing questions on drug use and sleep was completed by 1035 individuals. From this large sample, a group of 89 ecstasy users were found who reported very little use of other drugs. This ”ecstasy-only“ group was further divided into two groups of 31 current users and 58 abstinent users. The subjective sleep of current and former ecstasy-only users was compared with that of matched controls. Patients were asked to rate their sleep according to: 1) sleep quality, 2) sleep latency, 3) night time awakenings and 4) total sleep time. Current ecstasy-only users reported significantly worse sleep quality ( P < 0.05) and a greater total sleep time ( P < 0.001) than controls. It was inferred that these differences might be due to recovery from the acute effects of the drug. Abstinent ecstasy-only users reported significantly more nighttime awakenings than controls ( P < 0.01). These subjective findings are in agreement with the objective findings of previous studies showing persistent sleep abnormalities in ecstasy users.
CCK-4-induced anxiety but not panic is associated with serum brain-derived neurotrophic factor in healthy subjects
Authors: Maron E , Tõru I , Mäemets K , Sepp S , Vasar V , Shlik J , Zharkovsky A 
Published: June 2008

Abstract Recent animal studies consistently confirm the involvement of brain-derived neurotrophic factor (BDNF) in the regulation of anxiety-related behaviours. The role of BDNF in human anxiety has been less investigated. The aim of our study was to examine the association between serum BDNF levels and panic/anxiety responses to cholecystokinin-tetrapeptide (CCK-4) challenge in healthy subjects. BDNF concentrations were detected in serum samples of 37 male and female volunteers before and 120 min after CCK-4 injection. The baseline levels of serum BDNF did not predict the occurrence of CCK-4-induced panic attacks or intensity of panic symptoms and did not significantly change 2 h after the challenge. BDNF serum concentrations 120 min after provocation did not differentiate panickers from non-panickers; however, the subjects reporting stronger anxiety response showed higher levels of BDNF than those with mild anxiety. The anxiety net increase on the Visual Analogue Scale, but not severity of panic symptoms, significantly and positively correlated with the change in BDNF concentration from baseline values. This is the first challenge study to demonstrate a possible impact of BDNF on human anxiety. Our findings suggest a general involvement of BDNF in the regulation of anxiety rather than a specific role of BDNF in disposition to panic attacks.
A comparison of the effects of a subtype selective and non-selective benzodiazepine receptor agonist in two CO2 models of experimental human anxiety
Authors: Bailey JE , Papadopoulos A , Seddon K , Nutt DJ 
Published: June 2008

AbstractStudies in human volunteers that can demonstrate proof of concept are attractive in that possible mechanisms and potential new drug treatments can be examined. We have been developing models of anxiety disorders using the inhalation of 7.5% CO2for 20 min to model generalised anxiety disorder, as well as using the previously reported 35% CO2as a model for panic anxiety. In a double-blind, placebo-controlled, three-way crossover study in 12 healthy volunteer subjects, we compared a full agonist at the benzodiazepine receptor that binds to four α-subtypes of the receptor (α-1,-2,-3,-5) (alprazolam 1 mg), with zolpidem (5 mg), an agonist selective for the α-1 subtype of the gamma amino butyric acid-receptor subtype A (GABA-A) receptor, which is a widely used hypnotic drug. Compared with placebo, both drugs significantly attenuated peak CO2-induced changes in subjective feelings after the inhalation of 7.5% CO2for 20 min. However, there were fewer significant differences after a single vital capacity inhalation of 35% CO2, where zolpidem was less efficacious than alprazolam at reducing CO2-induced symptoms. In conclusion, our results show that zolpidem shows some anxiolytic efficacy in the 7.5% CO2model, similar to alprazolam, and this is the first report of such an effect of zolpidem in a model of anxiety. These and other studies of benzodiazepines in clinical and volunteer studies suggest a definite role of the GABA-A receptor in CO2-induced anxiety, and it would be of interest to examine other GABA-A receptor subtype selective drugs, which are now in early phase clinical studies and are showing selective efficacy in pharmacodynamic studies.
Amisulpride doses and plasma levels in different age groups of patients with schizophrenia or schizoaffective disorder
Authors: Müller MJ , Eich FX , Regenbogen B , Sachse J , Härtter S , Hiemke C 
Published: June 2008

Abstract Because of a unique pharmacodynamic profile, amisulpride seems appropriate for treatment of elderly patients with schizophrenia. In a large-scale naturalistic therapeutic drug monitoring study, daily amisulpride dose, trough and dose-corrected amisulpride plasma levels, co-medication, clinical effectiveness (CGI) and side effects (UKU) were compared between age groups in 395 patients with schizophrenia or schizoaffective disorder (46% women; mean age 39.1 ± 14.2 years, range 18–83 years) under amisulpride therapy. Mean amisulpride doses (574 ± 269 mg/day), plasma levels (304 ± 274 ng/mL), dose-corrected amisulpride plasma levels (C/D ratios, 0.52 ± 0.41 ng/mL:mg), clinical response (at least moderate improvement, 71.6%), and side effects (any side effect, 32.2%; extrapyramidal symptoms, 14.9%) were comparable between age groups ( P > 0.25). At higher age, significantly more benzodiazepines ( P = 0.04), non-benzodiazepine hypnotics ( P = 0.004) and non-psychotropic medications ( P < 0.0001) were prescribed. The naturalistic study showed higher C/D ratios in women ( P = 0.019) and a slight increase of C/D ratios with age ( P = 0.026), but no substantial age-dependent effects on amisulpride doses or plasma levels. In patients above 60 years, clinical response was associated with lower amisulpride plasma levels ( P = 0.016) at comparable doses. Neither the age-dependent decrease of amisulpride clearance nor the significantly higher prevalence of co-morbidity and co-medication seem to be the reasons for definite clinical concerns against amisulpride treatment of elderly if contraindications are seriously taken.