bluuebunny/crossref_metadata_2025 huggingface dataset:
Long-term ventilatory adaptation and ventilatory response to hypoxia in plateau pika (Ochotona curzoniae): role of nNOS and dopamine
Authors: Pichon Aurélien , Zhenzhong Bai , Favret Fabrice , Jin Guoen , Shufeng Han , Marchant Dominique , Richalet Jean-Paul , Ge Ri-Li
Published: July 2009

We assessed ventilatory patterns and ventilatory responses to hypoxia (HVR) in high-altitude (HA) plateau pikas, repetitively exposed to hypoxic burrows, and control rats. We evaluated the role of neuronal nitric oxide synthase (nNOS) and dopamine by using S-methyl-l-thiocitrulline (SMTC) inhibitor and haloperidol antagonist, respectively. Ventilation (V̇i) was measured using a whole body plethysmograph in conscious pikas ( n = 9) and low-altitude (LA) rats ( n = 7) at different PiO2(56, 80, 111, 150, and 186 mmHg) and in HA acclimatized rats ( n = 9, 8 days at 4,600 m) at two different PiO2(56 and 80 mmHg). The effects of NaCl, SMTC, and haloperidol on ventilatory patterns were assessed in pikas at PiO2= 56 and 80 mmHg. We observed a main species effect with larger V̇i, tidal volume (VT), inspiratory time/total time (Ti/Ttot), and a lower expiratory time in pikas than in LA rats. Pikas had also a larger VT and lower respiratory frequency compared with HA rats in hypoxia. HVR of pikas and rats were not statistically different. In pikas, SMTC induced a significant increase in V̇i and VT for a PiO2of 56 mmHg, but had no effect for a PiO2of 80 mmHg, i.e., the living altitude of pikas. In pikas, haloperidol injection had no effect on any ventilatory parameter. Long-term ventilatory adaptation in pikas is mainly due to an improvement in respiratory pattern (VT and Ti/Ttot) with no significant improvement in HVR. The sensitivity to severe acute hypoxia in pikas seems to be regulated by a peripheral nNOS mechanism.
Evidence that SLC26 anion transporters mediate branchial chloride uptake in adult zebrafish (Danio rerio)
Authors: Perry S. F. , Vulesevic B. , Grosell M. , Bayaa M.
Published: July 2009

Experiments were performed to test the hypothesis that three members of the SLC26 anion transporter gene family (SLC26a3, A4, and A6; hereafter termed za3, za4, and za6) mediate branchial Cl−/HCO3−exchange in adult zebrafish ( Danio rerio). Real-time RT-PCR demonstrated that the gill expressed relatively high levels of za6 mRNA; za3 and za4 mRNA, while present, were less abundant. Also, za4 and za6 were expressed at relatively high levels in the kidney. The results of in situ hybridization or immunocytochemistry (za3 only) experiments performed on gill sections revealed that the SLC26 transporters were predominantly expressed on the filament epithelium (especially within the interlamellar regions) and to a lesser extent on the lamellar epithelium at the base of lamellae. This distribution pattern suggests that the SLC26 anion transporters are localized to mitochondrion-rich cells (ionocytes). Transferring fish to water containing low [Cl−] (0.02 mmol/l) resulted in significant increases in branchial SLC26 mRNA expression after 5–10 days of exposure relative to fish raised in normal water [Cl−] (0.4 mmol/l); transferring fish to Cl−-enriched water (2.0 mmol/l) was without effect on mRNA levels. Transferring fish to water containing elevated levels of NaHCO3(10–12.5 mmol/l) caused marked increases in branchial SLC26 mRNA expression between 3 and 10 days of transfer that was associated with a significant 40% increase in Cl−uptake (as measured upon return to normal water after 7 days). A decrease in whole body net acid excretion (equivalent to an increase in net base excretion) in fish previously maintained in high [NaHCO3] water, concurrent with increases in Cl−uptake and SLC26 mRNA levels, suggests a role for these anion transporters in Cl−uptake and acid-base regulation owing to their Cl−/HCO3−exchange activities.
VRQ397 (CRAVKY): a novel noncompetitive V2 receptor antagonist
Authors: Rihakova L. , Quiniou C. , Hamdan F. F. , Kaul R. , Brault S. , Hou X. , Lahaie I. , Sapieha P. , Hamel D. , Shao Z. , Gobeil F. , Hardy P. , Joyal J-S. , Nedev H. , Duhamel F. , Beauregard K. , Heveker N. , Saragovi H. U. , Guillon G. , Bouvier M. , Lubell W. D. , Chemtob S.
Published: July 2009

Vasopressin type 2 receptor (V2R) exhibits mostly important properties for hydroosmotic equilibrium and, to a lesser extent, on vasomotricity. Drugs currently acting on this receptor are analogs of the natural neuropeptide, arginine vasopressin (AVP), and hence are competitive ligands. Peptides that reproduce specific sequences of a given receptor have lately been reported to interfere with its action, and if such molecules arise from regions remote from the binding site they would be anticipated to exhibit noncompetitive antagonism, but this has yet to be shown for V2R. Six peptides reproducing juxtamembranous regions of V2R were designed and screened; the most effective peptide, cravky (labeled VRQ397), was characterized. VRQ397 was potent (IC50= 0.69 ± 0.25 nM) and fully effective in inhibiting V2R-dependent physiological function, specifically desmopressin-l-desamino-8-arginine-vasopressin (DDAVP)-induced cremasteric vasorelaxation; this physiological functional assay was utilized to avoid overlooking interference of specific signaling events. A dose-response profile revealed a noncompetitive property of VRQ397; correspondingly, VRQ397 bound specifically to V2R-expressing cells could not displace its natural ligand, AVP, but modulated AVP binding kinetics (dissociation rate). Specificity of VRQ397 was further confirmed by its inability to bind to homologous V1 and oxytocin receptors and its inefficacy to alter responses to stimulation of these receptors. VRQ397 exhibited pharmacological permissiveness on V2R-induced signals, as it inhibited DDAVP-induced PGI2generation but not that of cAMP or recruitment of β-arrestin2. Consistent with in vitro and ex vivo effects as a V2R antagonist, VRQ397 displayed anticipated in vivo aquaretic efficacy. We hereby describe the discovery of a first potent noncompetitive antagonist of V2R, which exhibits functional selectivity, in line with properties of a negative allosteric modulator.
Prostacyclin-induced peroxisome proliferator-activated receptor-α translocation attenuates NF-κB and TNF-α activation after renal ischemia-reperfusion injury
Authors: Chen Hsi-Hsien , Chen Tzen-Wen , Lin Heng
Published: July 2009

Prostacyclin and peroxisome proliferator-activated receptors (PPAR) protect against ischemia-reperfusion (I/R) injury by the induction of an anti-inflammatory pathway. In this study, we examined the prostacyclin-enhanced protective effect of PPARα in I/R-induced kidney injury. PPAR-α reduced the NF-κB-induced overexpression of TNF-α and apoptosis in cultured kidney cells. In a murine model, pretreating wild-type (WT) mice with a PPAR-α activator, docosahexaenoic acid (DHA), significantly reduced I/R-induced renal dysfunction (lowered serum creatinine and urea nitrogen levels), apoptotic responses (decreased apoptotic cell number and caspase-3, -8 activation), and NF-κB activation. By comparison, I/R-induced injury was exacerbated in PPAR-α knockout mice. This indicated that PPAR-α attenuated renal I/R injury via NF-κB-induced TNF-α overexpression. Overexpression of prostacyclin using an adenovirus could also induce PPAR-α translocation from the cytosol into the nucleus to inhibit caspase-3 activation. This prostacyclin/PPAR-α pathway attenuated TNF-α promoter activity by binding to NF-κB. Using a cAMP inhibitor (CAY10441) and a prostacyclin receptor antibody, we also found that there was another prostacyclin/IP receptor/cAMP pathway that could inhibit TNF-α production. Taken together, our results demonstrate for the first time that prostacyclin induces the translocation of PPAR-α from the cytosol into the nucleus and attenuates NF-κB-induced TNF-α activation following renal I/R injury. Treatments that can augment prostacyclin, PPAR-α, or the associated signaling pathways may ameliorate conditions associated with renal I/R injury.
The role of calcium in the regulation of renin secretion
Authors: Beierwaltes William H.
Published: July 2009

Renin is the enzyme which is the rate-limiting step in the formation of the hormone angiotensin II. Therefore, the regulation of renin secretion is critical in understanding the control of the renin-angiotensin-aldosterone system and its many biological and pathological actions. Renin is synthesized, stored in, and released from the juxtaglomerular (JG) cells of the kidney. While renin secretion is positively regulated by the “second messenger” cAMP, unlike most secretory cells, renin secretion from the JG cell is inversely related to the extracellular and intracellular calcium concentrations. This novel relationship is referred to as the “calcium paradox.” This review will address observations made over the past 30 years regarding calcium and the regulation of renin secretion, and focus on recent observations which address this scientific conundrum. These include 1) receptor-mediated pathways for changing intracellular calcium; 2) the discovery of a calcium-inhibitable isoform of adenylyl cyclase associated with renin in the JG cells; 3) calcium-sensing receptors in the JG cells; 4) calcium-calmodulin-mediated signals; 5) the role of phosphodiesterases; and 6) connexins, gap junctions, calcium waves, and the cortical extracellular calcium environment. While cAMP is the dominant second messenger for renin secretion, calcium appears to modulate the integrated activities of the enzymes, which balance cAMP synthesis and degradation. Thus this review concludes that calcium modifies the amplitude of cAMP-mediated renin-signaling pathways. While calcium does not directly control renin secretion, increased calcium inhibits and decreased calcium amplifies cAMP-stimulated renin secretion.
Decreased abundance of urinary exosomal aquaporin-1 in renal ischemia-reperfusion injury
Authors: Sonoda Hiroko , Yokota-Ikeda Naoko , Oshikawa Sayaka , Kanno Yosuke , Yoshinaga Kazuya , Uchida Kazuyuki , Ueda Yuuji , Kimiya Kouichi , Uezono Shigehiro , Ueda Akira , Ito Katsuaki , Ikeda Masahiro
Published: July 2009

Urinary exosomes, secreted into urine from renal epithelial cells, are known to contain many types of renal functional membrane proteins. Here, we studied whether renal ischemia-reperfusion (I/R) affects urinary exosomal aquaporin-1 (AQP1) excretion in rats subjected to renal I/R and patients who underwent renal transplantation. Immunoblotting studies demonstrated reduction of the urinary exosomal AQP1 level even at 6 h after renal I/R, and the level continued to be low over 96 h after I/R. Renal AQP1 mRNA and protein analyses revealed that the decreased excretion of urinary exosomal AQP1 is associated with renal AQP1 protein retention in the early phase and with a decreased expression level of renal AQP1 in the later phase of renal I/R injury. Decreased abundance of urinary exosomal AQP1 in a recipient patient was also observed at 48 h after renal allograft transplantation. No significant decrease in urinary exosomal AQP1 was observed in a rat model of nephropathy or in patients with proteinuria. Our studies suggest that the renal AQP1 expression level is possibly controlled by its urinary exosomal excretion and indicate that urinary exosomal AQP1 is a novel urinary biomarker for renal I/R injury.
Inhibition of histone deacetylase activity attenuates renal fibroblast activation and interstitial fibrosis in obstructive nephropathy
Authors: Pang Maoyin , Kothapally Jagan , Mao Haiping , Tolbert Evelyn , Ponnusamy Murugavel , Chin Y. Eugene , Zhuang Shougang
Published: July 2009

Activation of renal interstitial fibroblasts is critically involved in the development of tubulointerstitial fibrosis in chronic kidney diseases. In this study, we investigated the effect of trichostatin A (TSA), a specific histone deacetylase (HDAC) inhibitor, on the activation of renal interstitial fibroblasts in a rat renal interstitial fibroblast line (NRK-49F) and the development of renal fibrosis in a murine model of unilateral ureteral obstruction (UUO) . α-Smooth muscle actin (α-SMA) and fibronectin, two hallmarks of fibroblast activation, were highly expressed in cultured NRK-49F cells, and their expression was inhibited in the presence of TSA. Similarly, administration of TSA suppressed the expression of α-SMA and fibronectin and attenuated the accumulation of renal interstitial fibroblasts in the kidney after the obstructive injury. Activation of renal interstitial fibroblasts was accompanied by phosphorylation of signal transducer and activator of transcription 3 (STAT3), and TSA treatment also abolished these responses. Furthermore, inhibition of the STAT3 pathway with AG490 inhibited expression of α-SMA and fibronectin in NRK-49F cells. Finally, TSA treatment inhibited tubular cell apoptosis and caspase-3 activation in the obstructive kidney. Collectively, we suggest that pharmacological HDAC inhibition may induce antifibrotic activity by inactivation of renal interstitial fibroblasts and inhibition of renal tubular cell death. STAT3 may mediate those actions of HDACs.
The renal H+-K+-ATPases: physiology, regulation, and structure
Authors: Gumz Michelle L. , Lynch I. Jeanette , Greenlee Megan M. , Cain Brian D. , Wingo Charles S.
Published: July 2009

The H+-K+-ATPases are ion pumps that use the energy of ATP hydrolysis to transport protons (H+) in exchange for potassium ions (K+). These enzymes consist of a catalytic α-subunit and a regulatory β-subunit. There are two catalytic subunits present in the kidney, the gastric or HKα1isoform and the colonic or HKα2isoform. In this review we discuss new information on the physiological function, regulation, and structure of the renal H+-K+-ATPases. Evaluation of enzymatic functions along the nephron and collecting duct and studies in HKα1and HKα2knockout mice suggest that the H+-K+-ATPases may function to transport ions other than protons and potassium. These reports and recent studies in mice lacking both HKα1and HKα2suggest important roles for the renal H+-K+-ATPases in acid/base balance as well as potassium and sodium homeostasis. Molecular modeling studies based on the crystal structure of a related enzyme have made it possible to evaluate the structures of HKα1and HKα2and provide a means to study the specific cation transport properties of H+-K+-ATPases. Studies to characterize the cation specificity of these enzymes under different physiological conditions are necessary to fully understand the role of the H+-K+ATPases in renal physiology.
Increased hypoxia and reduced renal tubular response to furosemide detected by BOLD magnetic resonance imaging in swine renovascular hypertension
Authors: Gomez Sabas I. , Warner Lizette , Haas John A. , Bolterman Rodney J. , Textor Stephen C. , Lerman Lilach O. , Romero Juan Carlos
Published: July 2009

Oxygen consumption beyond the proximal tubule is mainly determined by active solute reabsorption, especially in the thick ascending limb of the Loop of Henle. Furosemide-induced suppression of oxygen consumption (FSOC) involves inhibition of sodium transport in this segment, which is normally accompanied by a marked decrease in the intrarenal deoxyhemoglobin detectable by blood oxygen level-dependent (BOLD)-magnetic resonance imaging (MRI). This study tested the hypothesis that the magnitude of BOLD-MRI signal change after furosemide is related to impaired renal function in renovascular hypertension. In 16 pigs with unilateral renal artery stenosis, renal hemodynamics, function, and tubular function (FSOC and fluid concentration capacity) were evaluated in both kidneys using MR and multidetector computerized tomography (MDCT) imaging. Animals with adequate FSOC (23.6 ± 2.2%, P > 0.05 vs. baseline) exhibited a mean arterial pressure (MAP) of 113 ± 7 mmHg, and relatively preserved glomerular filtration rate (GFR) of 60 ± 4.5 ml/min, comparable to their contralateral kidney (66 ± 4 ml/min, P > 0.05). In contrast, animals with low FSOC (3.1 ± 2.1%, P = NS vs. baseline) had MAP of 124 ± 9 mmHg and GFR (22 ± 6 ml/min) significantly lower than the contralateral kidneys (66 ± 4 ml/min, P < 0.05). The group with preserved GFR and FSOC showed an increase in intratubular fluid concentration as assessed by MDCT that was greater than that observed in the low GFR group, suggesting better preservation of tubular function in the former group. These results suggest that changes in BOLD-MRI after furosemide can differentiate between underperfused kidneys with preserved tubular function and those with tubular dysfunction. This approach may allow more detailed physiologic evaluation of poststenotic kidneys in renovascular hypertension than previously possible.
Minimal Nielsen Root Classes and Roots of Liftings
Authors: Fenille Marcio Colombo , Neto Oziride Manzoli
Published: July 2009

Given a continuous map "Equation missing" from a 2-dimensional CW complex into a closed surface, the Nielsen root number "Equation missing" and the minimal number of roots "Equation missing" of "Equation missing" satisfy "Equation missing". But, there is a number "Equation missing" associated to each Nielsen root class of "Equation missing" and an important problem is to know when "Equation missing". In addition to investigate this problem, we determine a relationship between "Equation missing" and "Equation missing", when "Equation missing" is a lifting of "Equation missing" through a covering space, and we find a connection between this problems, with which we answer several questions related to them when the range of the maps is the projective plane.
Relaxed Composite Implicit Iteration Process for Common Fixed Points of a Finite Family of Strictly Pseudocontractive Mappings
Authors: Ceng L. C. , Shyu David S. , Yao J. C.
Published: July 2009

We propose a relaxed composite implicit iteration process for finding approximate common fixed points of a finite family of strictly pseudocontractive mappings in Banach spaces. Several convergence results for this process are established.
Antioxidant and Anticancer Activities of Wampee (Clausena lansium (Lour.) Skeels) Peel
Authors: Prasad K. Nagendra , Hao Jing , Yi Chun , Zhang Dandan , Qiu Shengxiang , Jiang Yueming , Zhang Mingwei , Chen Feng
Published: July 2009

Antioxidant activities of wampee peel extracts using five different solvents (ethanol, hexane, ethyl acetate, butanol and water) were determined by using in‐vitro antioxidant models including total antioxidant capability, 1,1‐diphenyl‐2‐picryl hydrazyl (DPPH) radical scavenging activity, reducing power, and superoxide scavenging activity. Ethyl acetate fraction (EAF) exhibited the highest antioxidant activity compared to other fractions, even higher than synthetic antioxidant butylated hydroxyl toluene (BHT). In addition, the EAF exhibited strong anticancer activities against human gastric carcinoma (SGC‐7901), human hepatocellular liver carcinoma (HepG‐2) and human lung adenocarcinoma (A‐549) cancer cell lines, higher than cisplatin, a conventional anticancer drug. The total phenolic content of wampee fraction was positively correlated with the antioxidant activity. This is the first report on the antioxidant and anticancer activities of the wampee peel extract. Thus, wampee peel can be used potentially as a readily accessible source of natural antioxidants and a possible pharmaceutical supplement.
Pleural FDG Uptake More Than a Decade after Talc Pleurodesis
Authors: Peek Hilke , van der Bruggen Wouter , Limonard Gijs
Published: July 2009

Talc pleurodesis induces a strong local inflammatory reaction which can be detected by PET scan for years after the procedure. When patients undergo PET scanning in the workup of a suspected malignancy later in life, pleural FDG uptake may unnecessarily lead to an additional invasive diagnostic workup. We present two cases of positive pleural PET findings more than 10 years after talc pleurodesis, where we adopted a watchful waiting approach. Positive pleural PET findings as a result of prior talc pleurodesis should always be included in the differential diagnosis of pleural abnormalities.
Nanoparticle-Delivered Suicide Gene Therapy Effectively Reduces Ovarian Tumor Burden in Mice
Authors: Huang Yu-Hung , Zugates Gregory T. , Peng Weidan , Holtz David , Dunton Charles , Green Jordan J. , Hossain Naushad , Chernick Michael R. , Padera Robert F. , Langer Robert , Anderson Daniel G. , Sawicki Janet A.
Published: July 2009

There is currently no effective therapy for patients with advanced ovarian cancer. To address the need for a more effective treatment for this deadly disease, we conducted preclinical tests in ovarian tumor–bearing mice to evaluate the therapeutic efficacy of using a cationic biodegradable poly(β-amino ester) polymer as a vector for nanoparticulate delivery of DNA encoding a diphtheria toxin suicide protein (DT-A). The promoter sequences of two genes that are highly active in ovarian tumor cells, MSLN and HE4, were used to target DT-A expression to tumor cells. Administration of DT-A nanoparticles directly to s.c. xenograft tumors and to the peritoneal cavity of mice bearing primary and metastatic ovarian tumors resulted in a significant reduction in tumor mass and a prolonged life span compared to control mice. Minimal nonspecific tissue and blood chemistry toxicity was observed following extended treatment with nanoparticles. DT-A nanoparticle therapy suppressed tumor growth more effectively than treatment with clinically relevant doses of cisplatin and paclitaxel. Our findings suggest that i.p. administration of polymeric nanoparticles to deliver DT-A encoding DNA, combined with transcriptional regulation to target gene expression to ovarian tumor cells, holds promise as an effective therapy for advanced-stage ovarian cancer. [Cancer Res 2009;69(15):6184–91]
The Development of a Selective Cyclin-Dependent Kinase Inhibitor That Shows Antitumor Activity
Authors: Ali Simak , Heathcote Dean A. , Kroll Sebastian H.B. , Jogalekar Ashutosh S. , Scheiper Bodo , Patel Hetal , Brackow Jan , Siwicka Alekasandra , Fuchter Matthew J. , Periyasamy Manikandan , Tolhurst Robert S. , Kanneganti Seshu K. , Snyder James P. , Liotta Dennis C. , Aboagye Eric O. , Barrett Anthony G.M. , Coombes R. Charles
Published: July 2009

Normal progression through the cell cycle requires the sequential action of cyclin-dependent kinases CDK1, CDK2, CDK4, and CDK6. Direct or indirect deregulation of CDK activity is a feature of almost all cancers and has led to the development of CDK inhibitors as anticancer agents. The CDK-activating kinase (CAK) plays a critical role in regulating cell cycle by mediating the activating phosphorylation of CDK1, CDK2, CDK4, and CDK6. As such, CDK7, which also regulates transcription as part of the TFIIH basal transcription factor, is an attractive target for the development of anticancer drugs. Computer modeling of the CDK7 structure was used to design potential potent CDK7 inhibitors. Here, we show that a pyrazolo[1,5-a]pyrimidine–derived compound, BS-181, inhibited CAK activity with an IC50 of 21 nmol/L. Testing of other CDKs as well as another 69 kinases showed that BS-181 only inhibited CDK2 at concentrations lower than 1 μmol/L, with CDK2 being inhibited 35-fold less potently (IC50 880 nmol/L) than CDK7. In MCF-7 cells, BS-181 inhibited the phosphorylation of CDK7 substrates, promoted cell cycle arrest and apoptosis to inhibit the growth of cancer cell lines, and showed antitumor effects in vivo. The drug was stable in vivo with a plasma elimination half-life in mice of 405 minutes after i.p. administration of 10 mg/kg. The same dose of drug inhibited the growth of MCF-7 human xenografts in nude mice. BS-181 therefore provides the first example of a potent and selective CDK7 inhibitor with potential as an anticancer agent. [Cancer Res 2009;69(15):6208–15]
Vascular Endothelial Growth Factor-C Protects Prostate Cancer Cells from Oxidative Stress by the Activation of Mammalian Target of Rapamycin Complex-2 and AKT-1
Authors: Muders Michael H. , Zhang Heyu , Wang Enfeng , Tindall Donald J. , Datta Kaustubh
Published: July 2009

Recurrence and subsequent metastatic transformation of cancer develops from a subset of malignant cells, which show the ability to resist stress and to adopt to a changing microenvironment. These tumor cells have distinctly different growth factor pathways and antiapoptotic responses compared with the vast majority of cancer cells. Long-term therapeutic success can only be achieved by identifying and targeting factors and signaling cascades that help these cells survive during stress. Both microarray and immunohistochemical analysis on human prostate cancer tissue samples have shown an increased expression of vascular endothelial growth factor-C (VEGF-C) in metastatic prostate cancer. We have discovered that VEGF-C acts directly on prostate cancer cells to protect them against oxidative stress. VEGF-C increased the survival of prostate cancer cells during hydrogen peroxide stress by the activation of AKT-1/protein kinase Bα. This activation was mediated by mammalian target of rapamycin complex-2 and was not observed in the absence of oxidative stress. Finally, the transmembrane nontyrosine kinase receptor neuropilin-2 was found to be essential for the VEGF-C–mediated AKT-1 activation. Indeed, our findings suggest a novel and distinct function of VEGF-C in protecting cancer cells from stress-induced cell death, thereby facilitating cancer recurrence and metastasis. This is distinctly different from the known function of VEGF-C in inducing lymphangiogenesis. [Cancer Res 2009;69(15):6042–8]
Prolonged Cell Cycle Response of HeLa Cells to Low-Level Alkylation Exposure
Authors: Schroering Allen G. , Kothandapani Anbarasi , Patrick Steve M. , Kaliyaperumal Saravanan , Sharma Vishal P. , Williams Kandace J.
Published: July 2009

Alkylation chemotherapy has been a long-standing treatment protocol for human neoplasia. N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) is a direct-acting monofunctional alkylator. Temozolomide is a clinical chemotherapeutic equivalent requiring metabolic breakdown to the alkylating agent. Both chemicals have similar mechanistic efficacy against DNA mismatch repair–proficient tumor cells that lack expression of methylguanine methyltransferase. Clinically relevant concentrations of both agents affect replicating cells only after the first cell cycle. This phenomenon has been attributed to replication fork arrest at unrepaired O6-methyldeoxyguanine lesions mispaired with thymine during the first replication cycle. Here, we show, by several different approaches, that MNNG-treated tumor cells do not arrest within the second cell cycle. Instead, the population slowly traverses through mitosis without cytokinesis into a third cell cycle. The peak of both ssDNA and dsDNA breaks occurs at the height of the long mitotic phase. The majority of the population emerges from mitosis as multinucleated cells that subsequently undergo cell death. However, a very small proportion of cells, <1:45,000, survive to form new colonies. Taken together, these results indicate that multinucleation within the third cell cycle, rather than replication fork arrest within the second cell cycle, is the primary trigger for cell death. Importantly, multinucleation and cell death are consistently avoided by a small percentage of the population that continues to divide. This information should prove clinically relevant for the future design of enhanced cancer chemotherapeutics. [Cancer Res 2009;69(15):6307–14]
Suppressor of Cytokine Signaling 3 Sensitizes Anaplastic Thyroid Cancer to Standard Chemotherapy
Authors: Francipane Maria Giovanna , Eterno Vincenzo , Spina Valentina , Bini Miriam , Scerrino Gregorio , Buscemi Giuseppe , Gulotta Gaspare , Todaro Matilde , Dieli Francesco , De Maria Ruggero , Stassi Giorgio
Published: July 2009

We previously showed that cancer cells from papillary, follicular, and anaplastic thyroid carcinomas produce interleukin-4 and interleukin-10, which counteract the cytotoxic activity of conventional chemotherapy through the up-regulation of antiapoptotic molecules. Here, we identify Janus kinase/signal transducers and activators of transcription (STAT) and phosphatidyl inositol 3-kinase (PI3K)/AKT as the down-stream pathways through which these cytokines confer resistance to cell death in thyroid cancer. We found that the absence of suppressors of cytokine signaling (SOCS) molecules allows the propagation of the survival signaling. Exogenous expression of SOCS1, SOCS3, and SOCS5 in the highly aggressive anaplastic thyroid cancer cells reduces or abolishes STAT3 and 6 phosphorylation and PI3K/Akt pathway activation resulting in alteration in the balance of proapoptotic and antiapoptotic molecules and sensitization to chemotherapeutic drugs in vitro. Likewise, exogenous expression of SOCS3 significantly reduces tumor growth and potently enhances the efficacy of chemotherapy in vivo. Our results indicate that SOCS3 regulation of cytokines-prosurvival programs might represent a new strategy to overcome the resistance to chemotherapy-induced cell death of thyroid cancer. [Cancer Res 2009;69(15):6141–8]
Differentiation of Lung Adenocarcinoma, Pleural Mesothelioma, and Nonmalignant Pulmonary Tissues Using DNA Methylation Profiles
Authors: Christensen Brock C. , Marsit Carmen J. , Houseman E. Andres , Godleski John J. , Longacker Jennifer L. , Zheng Shichun , Yeh Ru-Fang , Wrensch Margaret R. , Wiemels Joseph L. , Karagas Margaret R. , Bueno Raphael , Sugarbaker David J. , Nelson Heather H. , Wiencke John K. , Kelsey Karl T.
Published: July 2009

Pathologic differentiation of tissue of origin in tumors found in the lung can be challenging, with differentiation of mesothelioma and lung adenocarcinoma emblematic of this problem. Indeed, proper classification is essential for determination of treatment regimen for these diseases, making accurate and early diagnosis critical. Here, we investigate the potential of epigenetic profiles of lung adenocarcinoma, mesothelioma, and nonmalignant pulmonary tissues (n = 285) as differentiation markers in an analysis of DNA methylation at 1413 autosomal CpG loci associated with 773 cancer-related genes. Using an unsupervised recursively partitioned mixture modeling technique for all samples, the derived methylation profile classes were significantly associated with sample type (P < 0.0001). In a similar analysis restricted to tumors, methylation profile classes significantly predicted tumor type (P < 0.0001). Random forests classification of CpG methylation of tumors—which splits the data into training and test sets—accurately differentiated mesothelioma from lung adenocarcinoma over 99% of the time (P < 0.0001). In a locus-by-locus comparison of CpG methylation between tumor types, 1266 CpG loci had significantly different methylation between tumors following correction for multiple comparisons (Q < 0.05); 61% had higher methylation in adenocarcinoma. Using the CpG loci with significant differential methylation in a pathway analysis revealed significant enrichment of methylated gene-loci in Cell Cycle Regulation, DNA Damage Response, PTEN Signaling, and Apoptosis Signaling pathways in lung adenocarcinoma when compared with mesothelioma. Methylation profile–based differentiation of lung adenocarcinoma and mesothelioma is highly accurate, informs on the distinct etiologies of these diseases, and holds promise for clinical application. [Cancer Res 2009;69(15):6315–21]
Intravesical Immunotherapy of Superficial Bladder Cancer with Chitosan/Interleukin-12
Authors: Zaharoff David A. , Hoffman Benjamin S. , Hooper H. Brooks , Benjamin Compton J. , Khurana Kiranpreet K. , Hance Kenneth W. , Rogers Connie J. , Pinto Peter A. , Schlom Jeffrey , Greiner John W.
Published: July 2009

Intravesical BCG has been used successfully to treat superficial bladder cancer for three decades. However, 20% to 30% of patients will fail initial BCG therapy and 30% to 50% of patients will develop recurrent tumors within 5 years. Alternative or complementary strategies for the management of superficial bladder cancer are needed. Interleukin-12 (IL-12) is a potent TH1 cytokine with robust antitumor activity and the ability to potentiate immunologic memory. Unfortunately, intravesical IL-12 did not show antitumor efficacy in a recent clinical study of patients with recurrent superficial bladder cancer. We hypothesized that coformulation of IL-12 with chitosan, a biocompatible, mucoadhesive polysaccharide, could improve intravesical IL-12 delivery and provide an effective and durable alternative for the treatment of superficial bladder cancer. In antitumor studies, 88% to 100% of mice bearing orthotopic bladder tumors were cured after four intravesical treatments with chitosan/IL-12. In contrast, only 38% to 60% of mice treated with IL-12 alone and 0% treated with BCG were cured. Antitumor responses following chitosan/IL-12 treatments were durable and provided complete protection from intravesical tumor rechallenge. Urinary cytokine analysis showed that chitosan/IL-12 induced multiple TH1 cytokines at levels significantly higher than either IL-12 alone or BCG. Immunohistochemistry revealed moderate to intense tumor infiltration by T cells and macrophages following chitosan/IL-12 treatments. Bladder submucosa from cured mice contained residual populations of immune cells that returned to baseline levels after several months. Intravesical chitosan/IL-12 is a well-tolerated, effective immunotherapy that deserves further consideration for testing in humans for the management of superficial bladder cancer. [Cancer Res 2009;69(15):6192–9]
Inhibition of Superoxide Generation upon T-Cell Receptor Engagement Rescues Mart-127-35–Reactive T Cells from Activation-Induced Cell Death
Authors: Norell Håkan , Martins da Palma Telma , Lesher Aaron , Kaur Navtej , Mehrotra Meenal , Naga Osama S. , Spivey Natalie , Olafimihan Seye , Chakraborty Nitya G. , Voelkel-Johnson Christina , Nishimura Michael I. , Mukherji Bijay , Mehrotra Shikhar
Published: July 2009

Cytotoxic T lymphocytes (CTL) may undergo massive expansion upon appropriate antigenic stimulation. Homeostasis is maintained by a subsequent “contraction” of these cells. Activation-induced cell death (AICD) and programmed cell death prevent the untoward side effects, arising from excessive numbers and prolonged persistence of activated CTL, that occur upon uncontrolled and/or continued expansion. However, effector cell persistence has been identified as a hallmark of successful T-cell–mediated adoptive immunotherapy. Thus, prevention of AICD may be critical to achieve more successful clinical results. We have previously shown that treatment with the c-Jun NH2-terminal kinase (JNK) inhibitor SP600125 protects human melanoma epitope Mart-127-35–reactive CTL from apoptotic death upon their reencounter with cognate antigen. However, inhibition of JNK also interferes with the functional ability of the CTL to secrete IFN-γ. Here, we show that reactive oxygen species (ROS) inhibitors, such as the superoxide dismutase mimetic Mn (III) tetrakis (5, 10, 15, 20-benzoic acid) porphyrin (MnTBAP), efficiently protected Mart-127-35–reactive primary CTL from AICD without impairing their functional capability. MnTBAP prevented the increase in intracellular ROS, mitochondrial membrane collapse, and DNA fragmentation observed in control-treated cells upon cognate antigen encounter. Furthermore, the mechanism of AICD prevention in primary CTL included blockade of JNK activation. Finally, tumor-reactive in vitro expanded tumor infiltrating lymphocytes, which are used clinically in cancer immunotherapy, also benefit from MnTBAP-mediated antioxidant treatment. Thus, modulation of the redox pathway might improve CTL persistence and lead to better clinical results for T cell–based immunotherapies. [Cancer Res 2009;69(15):6282–9]
Prognostic Value of Biomarkers in Heart Failure
Authors: Dunlay Shannon M. , Gerber Yariv , Weston Susan A. , Killian Jill M. , Redfield Margaret M. , Roger Véronique L.
Published: July 2009

Background—

Mortality among patients with heart failure is high. Though individual biomarkers have been investigated to determine their value in mortality risk prediction, the role of a multimarker strategy requires further evaluation.

Methods and Results—

Olmsted County residents presenting with heart failure from July 2004 to September 2007 were recruited to undergo biomarker measurement. We investigated whether addition of C-reactive protein, B-type natriuretic peptide, and troponin T to a model including established risk indicators improved 1-year mortality risk prediction using the
c
statistic, integrated discrimination improvement, and net reclassification improvement. Among 593 participants, the mean age was 76.4 years, and 48% were men. After 1 year of follow-up, 122 (20.6%) participants had died. Patients with C-reactive protein (<11.8 mg/L), B-type natriuretic peptide (<350 pg/mL), and troponin T (≤0.01 ng/mL) less than the median had low 1-year mortality (3.3%), whereas those with 2 or 3 biomarkers greater than the median had markedly increased mortality (30.8% and 35.5%, respectively). The addition of 2 or more biomarkers to the model offered greater improvement in 1-year mortality risk prediction than use of a single biomarker. The combination of C-reactive protein and B-type natriuretic peptide resulted in an increase in the
c
statistic from 0.757 to 0.810 (
P
<0.001), an integrated discrimination improvement gain of 7.1% (
P
<0.001), and a net reclassification improvement of 22.1% (
P
<0.001). Use of all 3 biomarkers offered no incremental gain (integrated discrimination improvement gain 0.7% versus C-reactive protein+B-type natriuretic peptide,
P
=0.065).

Conclusions—

Biomarkers improved 1-year mortality risk prediction beyond established indicators. The use of a 2-biomarker combination was superior to a single biomarker in risk prediction, though addition of a third biomarker conferred no added benefit.
A Pilot Trial to Assess Potential Effects of Selective Intracoronary Bone Marrow–Derived Progenitor Cell Infusion in Patients With Nonischemic Dilated Cardiomyopathy
Authors: Fischer-Rasokat Ulrich , Assmus Birgit , Seeger Florian H. , Honold Jörg , Leistner David , Fichtlscherer Stephan , Schächinger Volker , Tonn Torsten , Martin Hans , Dimmeler Stefanie , Zeiher Andreas M.
Published: July 2009

Background—

Intracoronary administration of bone marrow–derived progenitor cells (BMC) was shown to improve coronary microvascular function in ischemic heart disease. Because coronary microvascular dysfunction is implicated in the pathogenesis and prognosis of nonischemic dilated cardiomyopathy (DCM), we investigated the effects of intracoronary BMC administration in patients with DCM.

Methods and Results—

Intracoronary infusion of BMC was performed in 33 patients with DCM by using an over-the-wire balloon catheter. Left ventricular contractility at baseline and after 3 months was assessed by analysis of left ventricular angiograms. Coronary hemodynamics were determined by intracoronary Doppler wire measurements. After 3 months, regional wall motion of the target area (contractility from −1.08�0.39 to −0.97�0.47 SD/chord,
P
=0.029) and global left ventricular ejection fraction (from 30.2�10.9 to 33.4�11.5%,
P
<0.001) were improved. Increase of regional contractile function was directly related to the functionality of the infused cells as measured by their colony-forming capacity. Minimal vascular resistance index was significantly reduced in the BMC-treated vessel after 3 months (from 1.53�0.63 to 1.32�0.61 mm Hg � s/cm;
P
=0.002, n=24), whereas no changes were observed in the reference vessel (from 1.60�0.45 to 1.49�0.45 mm Hg � s/cm;
P
=0.133, n=13). Twelve months after BMC infusion, N-terminal prohormone brain natriuretic peptide (NT-proBNP) serum levels were decreased, suggesting a beneficial effect on left ventricular remodeling processes (from 1610�993 to 1473�1147 pg/mL;
P
=0.038 for logNT-proBNP, n=26).

Conclusions—

Intracoronary administration of BMC seems to be associated with improvements in cardiac contractile and microvascular function in patients with DCM. Thus, randomized blinded studies are warranted to evaluate potential clinical benefits of intracoronary BMC administration in patients with DCM.
Catheter-Based Delivery of Fluid Paclitaxel for Prevention of Restenosis in Native Coronary Artery Lesions After Stent Implantation
Authors: Herdeg Christian , Göhring-Frischholz Katrin , Haase Karl K. , Geisler Tobias , Zürn Christine , Hartmann Ulrike , Wöhrle Jochen , Nusser Thorsten , Dippon Jürgen , May Andreas E. , Gawaz Meinrad
Published: July 2009

Background—

Stents eluting antiproliferative drugs reduce the incidence of restenosis but delay healing of the vascular wall. We assessed the safety and efficacy of catheter-based local delivery of fluid paclitaxel in patients with coronary de novo stenoses after implantation of a bare metal stent.

Methods and Results—

We conducted a prospective, randomized trial comparing the local delivery of fluid paclitaxel after bare metal stent implantation (group I) with the implantation of a bare metal stent (group II) and the implantation of a paclitaxel-eluting stent (group III) in 204 patients. The primary end point was in-stent late lumen loss. Secondary end points included binary restenosis rate >50%, minimal lumen diameter, diameter stenosis, and a composite clinical end point (major adverse cardiac events and revascularization of the target lesion) 6 months after intervention. At 6 months, angiography showed an in-stent late lumen loss of 0.61±0.44 mm in group I versus 0.99±0.72 mm in group II (I versus II,
P
=0.0006) and 0.44±0.48 mm in group III (noninferiority of I versus III,
P
=0.023). The 1-sided 95% CI for the true difference of the means of in-stent late lumen loss in groups I and III was −∞ to 0.3174188. The cumulative overall rate of major cardiac events was 13.4% in group I, 26.8% in group II, and 14.9% in group III. Target lesion revascularization rate was 13.4% (group I), 22.1% (group II), and 13.4% (group III).

Conclusions—

Additional antiproliferative treatment of de novo lesions in native coronary arteries with catheter-based delivery of fluid paclitaxel after bare metal stenting was safe and significantly reduced neointimal proliferation, restenosis, and clinical events compared with bare metal stent implantation alone.
Two-Year Clinical, Angiographic, and Intravascular Ultrasound Follow-Up of the XIENCE V Everolimus-Eluting Stent in the Treatment of Patients With De Novo Native Coronary Artery Lesions
Authors: Claessen Bimmer E. , Beijk Marcel A. , Legrand Victor , Ruzyllo Witold , Manari Antonio , Varenne Olivier , Suttorp Maarten J. , Tijssen Jan G.P. , Miquel-Hebert Karine , Veldhof Susan , Henriques Jose P.S. , Serruys Patrick W. , Piek Jan J.
Published: July 2009

Background—

This article reports the 2-year clinical, angiographic, and intravascular ultrasound outcomes of the everolimus-eluting stent (EES) compared with the paclitaxel-eluting stent (PES) in the randomized SPIRIT II trial.

Methods and Results—

This was a prospective, single-blind clinical trial in which a total of 300 patients with de novo native coronary artery lesions were randomized to either EES or PES in a 3:1 fashion. Clinical follow-up was planned at 2 years in all patients. A subset of 152 patients underwent serial angiographic and intravascular ultrasound analyses at 6 months and 2 years. After 2 years, target lesion failure (cardiac death, myocardial infarction, and ischemia-driven target lesion revascularization) rates were 6.6% and 11% in EES and PES, respectively (
P
=0.31). At 6 months, a significant reduction in angiographic in-stent late loss and percentage volume obstruction measured by intravascular ultrasound was observed in the EES group. However, at 2-year follow-up, a late increased intimal hyperplasia growth after implantation of an EES was observed. There were no significant differences between EES and PES for in-stent late loss (EES, 0.33�0.37 mm versus PES, 0.34�0.34 mm;
P
=0.84) and percentage volume obstruction (EES, 5.18�6.22% versus PES, 5.80�6.31%;
P
=0.65) at 2 years. The incidence of stent thrombosis was low and comparable in both groups (EES, 0.9%; PES, 1.4%).

Conclusions—

Although the previously reported angiographic and clinical superiority of the EES has vanished over time, this report confirms and extends the previously demonstrated noninferiority in terms of in-stent late loss of the EES when compared with the PES up to 2-year follow-up. There were no significant differences between EES and PES in clinical, angiographic and intravascular ultrasound outcomes at 2 years.
Frequency of Allergic or Hematologic Adverse Reactions to Ticlopidine Among Patients With Allergic or Hematologic Adverse Reactions to Clopidogrel
Authors: Lokhandwala Juzar O. , Best Patricia J.M. , Butterfield Joseph H. , Skelding Kimberly A. , Scott Thomas , Blankenship James C. , Buckley Jeremy W. , Berger Peter B.
Published: July 2009

Background—

Clopidogrel and ticlopidine are structurally very similar. In patients with an allergic or hematologic adverse reaction to either one of these drugs, the likelihood that an allergic or hematologic adverse effect will develop to the other is unknown. It is also unknown whether a reaction to the second thienopyridine is likely to be life threatening.

Methods and Results—

Medical records from 2 academic institutions were reviewed to identify patients who had an allergic or hematologic adverse reaction to either of the 2 currently commercially available thienopyridines and who were subsequently prescribed the other thienopyridine. Patient demographics, details of the adverse reactions, and subsequent clinical course were reviewed. A total of 76 patients were identified with an allergic or hematologic adverse reaction to clopidogrel or ticlopidine who had also received the other thienopyridine. Fourteen (27%; 95% CI, 16 to 41) patients who had an allergic or hematologic adverse reactions to clopidogrel had a similar reaction to ticlopidine; none developed a life-threatening reaction. The most common reaction was a rash (93%).

Conclusions—

In patients with an allergic or hematologic adverse reaction to one thienopyridine, there seems to be an increased frequency of such reactions to the other thienopyridine. However, no patient had a life-threatening reaction after exposure to the alternative thienopyridine.
Mechanisms of Transendothelial Migration of Leukocytes
Authors: Muller William A.
Published: July 2009

A great deal of progress has been made recently in understanding the molecules and mechanisms that regulate transendothelial migration of leukocytes, or diapedesis, a critical step in the inflammatory response. This review focuses mainly on the active role of the endothelial cell in this process as it occurs at endothelial cell borders. It discusses some of the many molecules that have been reported to play a role in transendothelial migration and asks why so many molecules seem to be involved. The concept is emerging that diapedesis itself can be dissected into sequential steps controlled by specific molecule(s) at the endothelial cell border. Several mechanisms have been shown to play a critical role in transendothelial migration including signals derived from clustering of apically disposed intercellular adhesion molecule-1 and vascular cell adhesion molecule-1, disruption or loosening of adherens junctions, and targeted recycling of platelet/endothelial cell adhesion molecule and other molecules from the recently described lateral border recycling compartment. A hypothesis that integrates the various known mechanisms is proposed.