bluuebunny/crossref_metadata_2025_split huggingface dataset:
PPARγ inhibitors reduce tubulin protein levels by a PPARγ, PPARδ and proteasome‐independent mechanism, resulting in cell cycle arrest, apoptosis and reduced metastasis of colorectal carcinoma cells
Authors: Schaefer Katherine L. , Takahashi Hirokazu , Morales Victor M. , Harris Gianni , Barton Susan , Osawa Emi , Nakajima Atsushi , Saubermann Lawrence J. 
Published: November 2006

AbstractThe nuclear transcription factor peroxisome proliferator‐activated receptor‐gamma (PPARγ) has been identified as an important therapeutic target in murine models of colorectal cancer (CRC). To examine whether PPARγ inhibition has therapeutic effects in late‐stage CRC, the effects of PPARγ inhibitors on CRC cell survival were examined in CRC cell lines and a murine CRC model. Low doses (0.1–1 μM) of PPARγ inhibitors (T0070907, GW9662 and BADGE) did not affect cell survival, while higher doses (10–100 μM) of all 3 PPARγ inhibitors caused caspase‐dependent apoptosis in HT‐29, Caco‐2 and LoVo CRC cell lines. Apoptosis was preceded by altered cell morphology, and this alteration was not prevented by caspase inhibition. PPARγ inhibitors also caused dual G and M cell cycle arrest, which was not required for apoptosis or for morphologic alterations. Furthermore, PPARγ inhibitors triggered loss of the microtubule network. Notably, unlike other standard antimicrotubule agents, PPARγ inhibitors caused microtubule loss by regulating tubulin post‐transcriptionally rather than by altering microtubule polymerization or dynamics. Proteasome inhibition by epoxomicin was unable to prevent tubulin loss. siRNA‐mediated reduction of PPARγ and PPARδ proteins did not replicate the effects of PPARγ inhibitors or interfere with the inhibitors' effects on apoptosis, cell cycle or tubulin. PPARγ inhibitors also reduced CRC cell migration and invasion in assays in vitro and reduced both the number and size of metastases in a HT‐29/SCID xenograft metastatic model of CRC. These results suggest that PPARγ inhibitors are a novel potential antimicrotubule therapy for CRC that acts by directly reducing microtubule precursors. © 2006 Wiley‐Liss, Inc.
In vivo evaluation of the role of DNp73α protein in regulating the p53‐dependent apoptotic pathway after treatment with cytotoxic drugs
Authors: Sabatino Maria Antonietta , Previdi Sara , Broggini Massimo 
Published: November 2006

AbstractThe amino terminus truncated p73 isoform, ΔNp73α, shows dominant negative behavior toward TAp73 and wild‐type p53, and has oncogenic potential. By contrast, we recently showed that in HCT116 clones forced expression of ΔNp73α did not increase in vitro cellular resistance to anticancer agents. The purpose of this study was to characterize in vivo models and to investigate the functional interaction between the ΔNp73α isoform and the p53 pathway. Human colon carcinoma HCT116 clones expressing inducible ΔNp73α (HCT116/DN3, HCT116/DN14) and HCT116/8a (transfected with the mock empty vector), transplanted in immunodeficient nude mice, were used to study the antitumor activity of cis‐diammine‐dichloro‐platinum (cDDP) (4 mg/kg, i.v., q7d × 3) and Doxorubicin (DX) (7.5 mg/kg, i.v., q7d × 3), with or without tetracycline‐induced ΔNp73α overexpression. ΔNp73α expression was confirmed by RT‐PCR, immunoblotting and immunohistochemical analysis. ΔNp73α subcellular localization after DX treatment was checked by an immunofluorescence assay. Western blot was used to analyze p53, p21, Bax, Bcl‐2 and p53AIP1 expression. ΔNp73α overexpression did not modify the antitumor activity of either DX or cDDP in xenograft models. DX reduced ΔNp73α protein expression, without affecting its nuclear localization. p53, p21, Bax and p53AIP1 protein expression increased and Bcl‐2 decreased in HCT116 clone derived tumors 24 hr after DX exposure, independently of the presence of ΔNp73α. Overexpression of ΔNp73α does not affect tumor growth in vivo, does not increase the resistance of established tumors to anticancer agents and does not antagonize p53 apoptotic functions. © 2006 Wiley‐Liss, Inc.
Cetuximab induce antibody‐dependent cellular cytotoxicity against EGFR‐expressing esophageal squamous cell carcinoma
Authors: Kawaguchi Yoshihiko , Kono Koji , Mimura Kousaku , Sugai Hidemitsu , Akaike Hidenori , Fujii Hideki 
Published: November 2006

AbstractTo evaluate the possibility of treatment with antiepidermal growth factor receptor (EGFR) mAb, Cetuximab against esophageal squamous cell carcinoma (SCC), we performed detail analysis of the antibody‐dependent cellular cytotoxicity (ADCC) mediated by Cetuximab against esophageal SCC. Esophageal SCC cell lines with various levels of EGFR (n = 8) were evaluated for their Cetuximab‐mediated ADCC by 51Cr‐release assay. As a result, Cetuximab was able to induce ADCC against EGFR‐expressing esophageal SCC and the activities reflected the degree of EGFR expression on the esophageal SCC. The activities of Cetuximab‐mediated ADCC by patients' PBMC were impaired in comparison with those by healthy donors' PBMC. Moreover, the inhibition of transforming growth factor (TGF)‐β could enhance Cetuximab‐mediated ADCC against TGF‐β‐producing SCC. In conclusion, Cetuximab was able to induce ADCC against EGFR‐expressing esophageal SCC. Some modalities aiming at enhancing the Cetuximab‐mediated ADCC may be necessary for successful Cetuximab treatment of patients with esophageal SCC. © 2006 Wiley‐Liss, Inc.
Endogenous adenosine inhibits CNS terminal Ca2+ currents and exocytosis
Authors: Knott Thomas K. , Marrero Héctor G. , Fenton Richard A. , Custer Edward E. , Dobson James G. , Lemos José R. 
Published: November 2006

AbstractBursts of action potentials (APs) are crucial for the release of neurotransmitters from dense core granules. This has been most definitively shown for neuropeptide release in the hypothalamic neurohypophysial system (HNS). Why such bursts are necessary, however, is not well understood. Thus far, biophysical characterization of channels involved in depolarization‐secretion coupling cannot completely explain this phenomenon at HNS terminals, so purinergic feedback mechanisms have been proposed. We have previously shown that ATP, acting via P2X receptors, potentiates release from HNS terminals, but that its metabolite adenosine, via A1 receptors acting on transient Ca2+ currents, inhibit neuropeptide secretion. We now show that endogenous adenosine levels are sufficient to cause tonic inhibition of transient Ca2+ currents and of stimulated exocytosis in HNS terminals. Initial non‐detectable adenosine levels in the static bath increased to 2.9 µM after 40 min. These terminals exhibit an inhibition (39%) of their transient inward Ca2+ current in a static bath when compared to a constant perfusion stream. CPT, an A1 adenosine receptor antagonist, greatly reduced this tonic inhibition. An ecto‐ATPase antagonist, ARL‐67156, similarly reduced tonic inhibition, but CPT had no further effect, suggesting that endogenous adenosine is due to breakdown of released ATP. Finally, stimulated capacitance changes were greatly enhanced (600%) by adding CPT to the static bath. Thus, endogenous adenosine functions at terminals in a negative‐feedback mechanism and, therefore, could help terminate peptide release by bursts of APs initiated in HNS cell bodies. This could be a general mechanism for controlling transmitter release in these and other CNS terminals. J. Cell. Physiol. 210: 309–314, 2007. © 2006 Wiley‐Liss, Inc.
Cisplatin upregulates Saccharomyces cerevisiae genes involved in iron homeostasis through activation of the iron insufficiency‐responsive transcription factor Aft1
Authors: Kimura Akiko , Ohashi Kazuaki , Naganuma Akira 
Published: November 2006

AbstractThe response of Saccharomyces cerevisiae to cisplatin was investigated by examining variations in gene expression using cDNA microarrays and confirming the results by reverse transcription polymerase chain reaction (RT‐PCR). The mRNA levels of 14 proteins involved in iron homeostasis were shown to be increased by cisplatin. Interestingly, the expression of all 14 genes is known to be regulated by Aft1, a transcription factor activated in response to iron insufficiency. The promoter of one of these genes, FET3, has been relatively well studied, so we performed a reporter assay using the FET3 promoter and showed that an Aft1 binding site in the promoter region is indispensable for induction of transcription by cisplatin. The active domain of Aft1 necessary for activation of the FET3 promoter by cisplatin is identical to the one required for activation by bathophenanthroline sulfonate, an inhibitor of cellular iron uptake. Furthermore, we found that cisplatin inhibits the uptake of 55Fe(II) into yeast cells. These findings suggest that cisplatin activates Aft1 through the inhibition of iron uptake into the cells, after which the expression of Aft1 target genes involved in iron uptake might be induced. J. Cell. Physiol. 210: 378–384, 2007. © 2006 Wiley‐Liss, Inc.
FAK phosphorylation at Ser‐843 inhibits Tyr‐397 phosphorylation, cell spreading and migration
Authors: Jacamo Rodrigo , Jiang Xiaohua , Lunn J. Adrian , Rozengurt Enrique 
Published: November 2006

AbstractMultiple stimuli promote the tyrosine phosphorylation and activation of focal adhesion kinase (FAK), which ultimately facilitates migration. Little is known about the effect of adhesion‐dependent signals and cytoskeleton organization on the regulation of FAK phosphorylation at serine sites, or about the role of FAK serine phosphorylation in cell migration. Here, we show that FAK phosphorylation at Ser‐843 is strikingly increased when adherent cells are removed from the substratum and held in suspension or by treatment of adherent cells with cytochalasin D, conditions that disrupt the F‐actin cytoskeleton and promote focal adhesion disassembly. Notably, the increase in Ser‐843 phosphorylation was accompanied by a concomitant sharp decrease in Tyr‐397 phosphorylation. To further examine the cause‐effect relationship between these two phosphorylation sites we generated Ser‐843 phosphorylation‐deficient and phosphorylation‐mimicking FAK mutants. We found that mutation of Ser‐843 to aspartic acid (FAK[S843D]) markedly decreased FAK Tyr‐397 phosphorylation in integrin‐stimulated cells. While the migratory defect of FAK‐deficient fibroblasts was rescued by stable re‐expression of WT FAK or FAK[S843A], stable re‐expression of FAK[S843D] failed to restore the ability of the cells to migrate into the denuded area of a wound. Our results indicate that increased FAK phosphorylation at Ser‐843 represses FAK phosphorylation at Tyr‐397, thus suggesting a mechanism of cross‐talk between these phosphorylation sites that could regulate FAK‐mediated cell shape and migration. J. Cell. Physiol. 210: 436–444, 2007. © 2006 Wiley‐Liss, Inc.
Establishment of histone gene regulation and cell cycle checkpoint control in human embryonic stem cells
Authors: Becker Klaus A. , Stein Janet L. , Lian Jane B. , van Wijnen Andre J. , Stein Gary S. 
Published: November 2006

AbstractRapid self‐renewal of human embryonic stem (ES) cells (NIH designation WA01 and WA09) is accommodated by an abbreviated cell cycle due to a reduction in the G1 phase. Thus, molecular mechanisms operative in ES cells may expedite the cellular commitment to progress into S phase to initiate replication of DNA and biosynthesis of histone proteins to form new chromatin. Here we show that the selective cell cycle regulated expression of individual histone H4 gene copies, which is typical for somatic cell types, is already firmly established in human ES cells. This early establishment of H4 gene regulation, which is E2F independent, is consistent with co‐expression of the cognate transcriptional regulators HiNF‐P and p220NPAT. Human ES cells differ from somatic cells in the expression of members of the E2F family and RB‐related pocket proteins (p105RB1, p107RBL1, and p130RBL2/RB2) that control expression of genes encoding enzymes for nucleotide metabolism and DNA synthesis. Human ES cells rapidly and robustly (>200‐fold) induce the cyclin dependent kinase (CDK) inhibitor p21WAF1/CIP1 upon gamma‐irradiation. This DNA damage response promptly reduces histone gene expression as well as mRNA levels for HiNF‐P and p220NPAT and causes accumulation of unprocessed histone H4 precursor RNAs. Furthermore, while E2F4, E2F5 and p130RBL2/RB2 are the major E2F and pocket protein mRNAs in actively proliferating ES cells, expression levels of E2F5, E2F6, and p105RB1 are most strongly elevated during cell cycle arrest in cells responding to DNA damage. Our data suggest that the brief G1 phase of ES cells is supported by a potent p21WAF1/CIP1 related DNA damage response that functions through several mechanisms to rapidly inhibit cell cycle progression. This response may alter the E2F/pocket protein combinations that control E2F dependent genes and block H4 gene expression by inhibiting histone‐specific transcription factors and processing of histone gene transcripts, as well as by destabilizing histone mRNAs. J. Cell. Physiol. 210: 517–526, 2007. © 2006 Wiley‐Liss, Inc.
Detection of antigen‐specific T cells on p/MHC microarrays
Authors: Deviren Gokhan , Gupta Kapil , Paulaitis Michael E. , Schneck Jonathan P. 
Published: November 2006

AbstractThe development of high‐throughput protein microarrays for rapidly determining antigen‐specific T‐cell receptor repertoires of diverse T‐cell populations can enable comprehensive, broad‐based analyses of T‐cell responses. Promising applications include medical diagnostics, vaccine development, treatment of autoimmune diseases and detection of potential agents of bioterrorism. In this study, we examined the feasibility of using peptide/major histocompatibility complex (p/MHC) microarrays to selectively capture and enumerate antigen‐specific T cells. Results are presented for p/MHC microarrays consisting of a dimeric MHC‐immunoglobulin complex, Kb‐Ig, loaded with either a cognate or non‐cognate peptide for binding CD8+ T cells. We quantified the sensitivity of these Kb‐Ig microarrays by measuring a lower detection limit of 0.05% antigen‐specific CD8+ T cells mixed with splenocytes from C57BL/6J mouse. A fivefold increase in this lower detection limit (0.01%) was achieved using a secondary capture anti‐Ig antibody to coat the microarray surface. This higher sensitivity is comparable to that obtained using standard state‐of‐the‐art fluorescence activated cell sorting (FACS) instruments. We also found that contacting the T‐cell suspension with the Kb‐Ig microarrays under mild shear flow conditions produced more uniform distributions of captured T cells on the individual spots and better spot‐to‐spot reproducibility across the entire microarray. Copyright © 2006 John Wiley & Sons, Ltd.
Measurement of DTI metrics in hemorrhagic brain lesions: Possible implication in MRI interpretation
Authors: Haris Mohammad , Gupta Rakesh K , Husain Nuzhat , Hasan Khader M , Husain Mazhar , Narayana Ponnada A 
Published: November 2006

AbstractPurposeTo understand the biological basis of possible mechanisms responsible for increased fractional anisotropy (FA) in different stages of hemorrhage and hemorrhagic brain lesions.Materials and MethodsA total of 19 patients with cerebral hemorrhage (CH), five patients with hemorrhagic infarct (HI), and nine patients with hemorrhagic brain tumor (HBT) were prospectively evaluated with diffusion tensor imaging (DTI) and the FA and mean diffusivity (MD) was quantified. Ex vivo DTI of blood clot and histology of the blood clot and HBT were performed to interpret the temporal changes in the DTI metrics.ResultsHigh FA (>0.20) with low MD in the acute and early subacute stage and low FA (<0.20) with increased MD in the late subacute and chronic stage of CH and HI were observed. HBT showed high FA with low MD at all stages. In CH and HI, a significant reduction in FA (P < 0.001) with increased MD (P < 0.001) was seen in the late subacute and chronic stages compared to the acute and early subacute stages, normal white matter (NWM), and HBT. In HBT, there was no significant statistical difference in the FA values between different stages. Histology of HBT and ex vivo blood clot showed structural organization of intact red blood cells (RBCs) with fibrin mesh where the FA values were high compared to normal tissue region that is devoid of blood.ConclusionIntact RBCs entangled within fibrin mesh appear to be responsible for high FA in hemorrhagic brain lesions. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
In vivo perfusion, T1, and T2 measurements in the female pelvis during the normal menstrual cycle: A feasibility study
Authors: Hoad Caroline L. , Fulford Jonathan , Raine‐Fenning Nick J. , Campbell Bruce K. , Johnson Ian R. , Gowland Penelope A. 
Published: November 2006

AbstractPurposeTo quantify T1, T2, and regional tissue perfusion in uterine tissues, with MR imaging in clinically feasible imaging times, using echo planar imaging (EPI) techniques over a single menstrual cycle.Materials and MethodsA total of 24 healthy ovulating women were scanned; however, complete data sets through the menstrual cycle were not obtained from all women. Three scans were performed to coincide prospectively with the follicular, periovulatory, and luteal phases of the cycle. T1 and perfusion were measured simultaneously using flow alternating inversion recovery (FAIR), while T2 was measured using a single Hahn spin‐echo (SE) EPI sequence.ResultsBetween the follicular and periovulatory phases, statistically significant increases (P < 0.05) were seen for the T2 of the endometrium and perfusion of the myometrium as well as the T2/T1 ratio for both endometrium and myometrium. A statistically significant decrease was seen in the endometrial T2 between the periovulatory and luteal phases of the cycle. Tissue differentiation was achieved using the parameters measured, with T1 and T2 being statistically greater for the endometrium than for the myometrium, and endometrial perfusion being statistically lower than myometrial perfusion.ConclusionThese results show the feasibility of using these techniques to measure T1, T2, and perfusion in uterine tissues and of extending this work to study pathological conditions. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Fragmentation induced in atmospheric pressure photoionization of peptides
Authors: Debois D. , Giuliani A. , Laprévote O. 
Published: November 2006

AbstractIn this work, the fragmentation of peptides under atmospheric pressure photoionization conditions is investigated. Intensive fragmentations into b/y‐ and c‐sequence ions are reported. Abundance of these c‐ions appeared to be related to the quantity of dopant infused and to the disappearance of the doubly protonated peptide ion. A careful analysis of the role of the dopant indicates that the fragmentations are not dependent on the nature of the dopant but on their ionization efficiencies. This result shows that the fragmentation arises from the reaction of the protonated peptide with photoelectrons released upon ionization of the dopant in an electron capture dissociation/electron transfer dissociation (ECD/ETD) type mechanism. Experiments with peptides bearing a single proton indicate that additional mechanisms are involved. H‐atom transfer reactions are suggested to be responsible for the fragmentations as well. Those atoms could arise either from the dopant ions or from negatively charged solvent nanodroplets. This is the first report of an ECD/ETD mechanism in a dense medium and at atmospheric pressure. Copyright © 2006 John Wiley & Sons, Ltd.
The effects of pulse energy variations on the dimensions of microscopic thermal treatment zones in nonablative fractional resurfacing
Authors: Bedi Vikramaditya P. , Chan Kin Foong , Sink R. Kehl , Hantash Basil M. , Herron G. Scott , Rahman Zakia , Struck Steven K. , Zachary Christopher B. 
Published: November 2006

AbstractBackground and ObjectivesWe examined the effects of pulse energy variations on the dimensions of microscopic thermal injury zones (MTZs) created on human skin ex vivo and in vivo using nonablative fractional resurfacing.Materials and MethodsA Fraxel® SR laser system emitting at 1,550 nm provided an array of microscopic spots at variable densities. Pulse energies ranging from 4.5 to 40mJ were tested on human abdominal skin ex vivo and in vivo. Tissue sections were stained with hematoxylin and eosin (H&E) or nitro blue tetrazolium chloride (NBTC) and MTZ dimensions were determined. Ex vivo and in vivo results were compared. Dosimetry analyses were made for the surface treatment coverage calculation as a function of pulse energy and collagen coagulation based on H&E stain or cell necrotic zone based on NBTC stain.ResultsEach MTZ was identified by histological detection of a distinct region of loss of tissue birefringence and hyalinization, representing collagen denaturation and cell necrosis within the irradiated field immediately, 1, 3, and 7days after treatment. At high pulse energies, the MTZ depth could exceed 1 mm and width approached 200 µm as assessed by H&E. NBTC staining revealed viable interlesional tissue. In general, no statistically significant difference was found between in vivo and ex vivo depth and width measurements.ConclusionsThe Fraxel® SR laser system delivers pulses across a wide range of density and energy levels. We determined that increases in pulse energy led to increases in MTZ depth and width without compromising the structure or viability of interlesional tissue. Lasers Surg. Med. 39:157–163, 2007. © 2007 Wiley‐Liss, Inc.
Detection of sentinel nodes by a novel red‐fluorescent dye, ATX‐S10Na (II), in an orthotopic xenograft rat model of human gastric carcinoma
Authors: Koyama Tomoki , Tsubota Akihito , Nariai Koichi , Yoshikawa Tetsuya , Mitsunaga Makoto , Sumi Makoto , Nimura Hiroshi , Yanaga Katsuhiko , Yumoto Yoko , Mabashi Yasuo , Takahashi Hiroshi 
Published: November 2006

AbstractBackground and ObjectiveWe developed a new imaging system to detect sentinel nodes (SNs) using a novel fluorescent tracer, ATX‐S10Na(II), and investigated its usefulness in an animal model.Study Design/Materials and MethodsHuman gastric carcinoma cells were implanted orthotopically into nude rats. ATX‐S10Na(II) was injected subserosally into the primary tumor lesion, and visualized by a fluorescence spectro‐laparoscope. Presence of tumor cells in lymph nodes (LNs) was determined by RT‐PCR specific for human β‐actin.ResultsInjection of ATX‐S10Na(II) was successful in 27 tumor‐bearing rats. A red fluorescence was incorporated into the left gastric and hepatic LNs in 25 and 2 rats, respectively. Of note, human β‐actin was detected in most of these LNs. Fluorescence was not detected in LNs that did not contain cancer.ConclusionATX‐S10Na(II) is useful for the detection of cancer‐containing SNs in an animal model of gastric carcinoma, and may serve as a novel tracer in SN navigation surgery. Lasers Surg. Med. © 2006 Wiley‐Liss, Inc.
Biaxial Orientation in Triple Centrifuged Natural Rubber
Authors: Alam Mohammad Mahay , Asano Tsutomu 
Published: November 2006

AbstractNatural rubber (NR) latex was purified through triple centrifugation process and film samples were prepared. The strain‐induced crystallization was studied during the uniaxial elongation of the NR samples at room temperature. Crystalline orientation was detected by wide angle x‐ray diffraction (WAXD) measuring the intensity of 200 and 120 reflections. The WAXD patterns were compared with the aspect ratio (width/length) of the original NR films. The results indicate that the induced crystals have a biaxial orientation (BO), where the c‐axis is parallel to the draw direction and the a‐axis is parallel to the film surface. Using the WAXD through patterns, we distinguish the highly oriented BO region in the samples. In order to analyze the structure and properties of the NR, the effect of BO is an essential factor.