bluuebunny/crossref_metadata_2025 huggingface dataset:
Hypothalamic paraventricular nucleus mediates sodium-induced changes in cardiovascular and renal function in conscious sheep
Authors: Frithiof Robert , Ramchandra Rohit , Hood Sally , May Clive , Rundgren Mats
Published: May 2009

The contribution of the paraventricular nucleus of the hypothalamus (PVN) in mediating cardiovascular, renal, hormonal, and sympathetic nerve responses to increased cerebrospinal fluid (CSF) [Na+] was investigated in conscious sheep. Intracerebroventricular hypertonic NaCl (0.5 mol/l, 20 μl/min for 60 min) increased arterial blood pressure [AP; +13.4 (sd 2.0) mmHg, P < 0.001] and central venous pressure [CVP; +2.8 (sd 1.3) mmHg, P < 0.001], but did not significantly change heart rate or cardiac output ( n = 6). Elevated CSF [Na+] also lowered plasma ANG II levels [−3.3 (sd 1.6) pmol/l, P = 0.004] and increased creatinine clearance [+31.5 (sd 32.7) ml/min, P = 0.03] and renal sodium excretion [+9.2 (sd 9.2) mmol/h, P = 0.003]. Lidocaine injection (1 μl, 2%) into the PVN prior to the ICV infusion had no apparent effect per se, but it abolished the AP, CVP, creatinine clearance, and ANG II responses to hypertonic NaCl, as well as reducing the increase in renal sodium excretion ( n = 6). Subsequent studies were performed in conscious sheep with chronically implanted electrodes for measurement of renal sympathetic nerve activity (RSNA). The effects of ICV hypertonic NaCl on AP and RSNA were measured before and after PVN-injection of glycine (250 nmol in 500 nl artificial CSF). ICV NaCl increased AP and decreased RSNA ( P < 0.001). These effects were significantly reduced by glycine ( P = 0.02–0.001, n = 5). Saline injected into the PVN ( n = 5) or lidocaine injected outside the PVN ( n = 6) had no effect on the response to ICV hypertonic NaCl. These results indicate that the PVN is an important mediator of cerebrally induced homeostatic responses to elevated sodium concentration/hyperosmolality.
VEGF kinase inhibitors: how do they cause hypertension?
Authors: Bhargava Pankaj
Published: May 2009

Neoangiogenesis is a critical phenomenon enabling the growth and metastasis of tumors, and inhibitors of neoangiogenesis have been recently added to the armamentarium of anticancer therapies available for clinical use. Dysregulated signaling through the vascular endothelial growth factor (VEGF) pathway has been implicated as a key mediator of neoangiogenesis in tumors. Agents that block signaling through the VEGF pathway demonstrated tumor shrinkage in preclinical models and were therefore developed as anticancer therapies for use in humans. VEGF kinase inhibitors are being used in the treatment of a wide variety of cancers, and recent studies have shown that patients will likely require long-term treatment with these agents. Hypertension has emerged as a frequent side effect associated with agents that block signaling through the VEGF pathway. A thorough understanding of the mechanisms underlying hypertension is crucial to developing appropriate therapeutic strategies for treating hypertension associated with VEGF kinase inhibitors. Several recent studies have advanced our understanding of the pathophysiology of hypertension associated with VEGF kinase inhibitors and will be the subject of this review.
NAADP receptors mediate calcium signaling stimulated by endothelin-1 and norepinephrine in renal afferent arterioles
Authors: Thai Tiffany L. , Churchill Grant C. , Arendshorst William J.
Published: May 2009

The enzyme ADP-ribosyl (ADPR) cyclase plays a significant role in mediating increases in renal afferent arteriolar cytosolic calcium concentration ([Ca2+]i) in vitro and renal vasoconstriction in vivo. ADPR cyclase produces cyclic ADP ribose, a second messenger that contributes importantly to ryanodine receptor-mediated Ca2+mobilization in renal vascular responses to several vasoconstrictors. Recent studies in nonrenal vascular smooth muscle cells (VSMC) have shown that nicotinic acid adenine dinucleotide phosphate (NAADP), another second messenger generated by ADPR cyclase, may contribute to Ca2+signaling. We tested the hypothesis that a Ca2+signaling pathway involving NAADP receptors participates in afferent arteriolar [Ca2+]iresponses to the G protein-coupled receptor agonists endothelin-1 (ET-1) and norepinephrine (NE). To test this, we isolated rat renal afferent arterioles and measured [Ca2+]Iusing fura-2 fluorescence. We compared peak [Ca2+]iincreases stimulated by ET-1 and NE in the presence and absence of inhibitors of acidic organelle-dependent Ca2+signaling and NAADP receptors. Vacuolar H+-ATPase inhibitors bafilomycin A1 and concanamycin A, disruptors of pH and Ca2+stores of lysosomes and other acidic organelles, individually antagonized [Ca2+]iresponses to ET-1 and NE by 40–50% ( P < 0.05). The recently discovered NAADP receptor inhibitor Ned-19 attenuated [Ca2+]iresponses to ET-1 or NE by 60–70% ( P < 0.05). We conclude that NAADP receptors contribute to both ET-1- and NE-induced [Ca2+]iresponses in afferent arterioles, an effect likely dependent on acidic vesicle, possibly involving lysosome, signaling in VSMC in the renal microcirculation.
β1-Integrin is required for kidney collecting duct morphogenesis and maintenance of renal function
Authors: Wu Wei , Kitamura Shinji , Truong David M. , Rieg Timo , Vallon Volker , Sakurai Hiroyuki , Bush Kevin T. , Vera David R. , Ross Robert S. , Nigam Sanjay K.
Published: May 2009

Deletion of integrin-β1 ( Itgb1) in the kidney collecting system led to progressive renal dysfunction and polyuria. The defect in the concentrating ability of the kidney was concomitant with decreased medullary collecting duct expression of aquaporin-2 and arginine vasopressin receptor 2, while histological examination revealed hypoplastic renal medullary collecting ducts characterized by increased apoptosis, ectasia and cyst formation. In addition, a range of defects from small kidneys with cysts and dilated tubules to bilateral renal agenesis was observed. This was likely due to altered growth and branching morphogenesis of the ureteric bud (the progenitor tissue of the renal collecting system), despite the apparent ability of the ureteric bud-derived cells to induce differentiation of the metanephric mesenchyme. These data not only support a role for Itgb1 in the development of the renal collecting system but also raise the possibility that Itgb1 links morphogenesis to terminal differentiation and ultimately collecting duct function and/or maintenance.
Forced expiratory flows and volumes in intubated and paralyzed infants and children: normative data up to 5 years of age
Authors: von Ungern-Sternberg Britta S. , Trachsel Daniel , Erb Thomas O. , Hammer Jürg
Published: May 2009

Reference equations that express indexes obtained from forced expiratory maneuvers in relation to height and/or other independent variables are lacking for infants and children with artificial airways. The present study was performed to establish normative data of forced expiration by forced deflation in healthy intubated and paralyzed infants and children and to develop prediction equations in relation to height and to ulna length to enable pulmonary assessments in children whose height is difficult to measure. Measurements of forced and passive expiratory maneuvers after inflation to +40 cmH2O inspiratory pressure were prospectively obtained in 100 healthy anesthetized children from 0 to 5 yr of age. Linear regressions of log-transformed forced vital capacity (FVC) and maximum expiratory flow at 25% and 10% FVC (MEF25 and MEF10, respectively) obtained by forced deflation (−40 cmH2O airway opening pressure) and of analogous indexes obtained by passive deflation were used to develop prediction equations from height or ulna length. FVC was significantly dependent on age and height or ulna length. Prediction equations for FVC using height or ulna length were as follows: ln(FVC in ml) = −5.6 + 2.8 × ln(height in cm) and ln(FVC in ml) = 0.46 + 2.5 × ln(ulna length in cm). Younger subjects had a significantly steeper slope for FVC vs. height than the older age group. Normal reference data for forced expiratory maneuvers in intubated infants and children up to 5 yr of age will enable improved assessment of pulmonary dysfunction in acutely or chronically ventilator-dependent children. Using ulna length instead of height should facilitate respiratory assessment in ventilated children with spinal or joint deformities.
Temporal Evolution of “Automatic Gain-Scaling”
Authors: Pruszynski J. Andrew , Kurtzer Isaac , Lillicrap Timothy P. , Scott Stephen H.
Published: May 2009

The earliest neural response to a mechanical perturbation, the short-latency stretch response (R1: 20–45 ms), is known to exhibit “automatic gain-scaling” whereby its magnitude is proportional to preperturbation muscle activity. Because gain-scaling likely reflects an intrinsic property of the motoneuron pool (via the size-recruitment principle), counteracting this property poses a fundamental challenge for the nervous system, which must ultimately counter the absolute change in load regardless of the initial muscle activity (i.e., show no gain-scaling). Here we explore the temporal evolution of gain-scaling in a simple behavioral task where subjects stabilize their arm against different background loads and randomly occurring torque perturbations. We quantified gain-scaling in four elbow muscles (brachioradialis, biceps long, triceps lateral, triceps long) over the entire sequence of muscle activity following perturbation onset—the short-latency response, long-latency response (R2: 50–75 ms; R3: 75–105 ms), early voluntary corrections (120–180 ms), and steady-state activity (750–1250 ms). In agreement with previous observations, we found that the short-latency response demonstrated substantial gain-scaling with a threefold increase in background load resulting in an approximately twofold increase in muscle activity for the same perturbation. Following the short-latency response, we found a rapid decrease in gain-scaling starting in the long-latency epoch (∼75-ms postperturbation) such that no significant gain-scaling was observed for the early voluntary corrections or steady-state activity. The rapid decrease in gain-scaling supports our recent suggestion that long-latency responses and voluntary control are inherently linked as part of an evolving sensorimotor control process through similar neural circuitry.
Inflammation-dependent expression of SPARC during development of chronic pancreatitis in WBN/Kob rats and a microarray gene expression analysis
Authors: Reding T. , Wagner U. , Silva A. B. , Sun L-K. , Bain M. , Kim S.-Y. , Bimmler D. , Graf R.
Published: May 2009

The pathophysiology of human chronic pancreatitis is not well understood and difficult to follow on a molecular basis. Therefore, we used a rat model [Wistar-Bonn/Kobori (WBN/Kob)] that exhibits spontaneous chronic inflammation and fibrosis in the pancreas. Using microarrays we compared gene expression patterns in the pancreas during development of inflammation and fibrosis of WBN/Kob rats with age-matched healthy Wistar rats. The extracellular matrix protein SPARC (secreted protein, acidic, and rich in cysteines) and other transcripts of inflammatory genes were quantified by real-time PCR, and some were localized by immunohistochemistry. When pancreatic inflammation becomes obvious at the age of 16 wk, several hundred genes are increased between 3- and 50-fold in WBN/Kob rats compared with healthy Wistar rats. Proteins produced by acinar cells and characteristic for inflammation, e.g., pancreatitis-associated protein, are highly upregulated. Other proteins, derived from infiltrating inflammatory cells and from activated stellate cells (fibrosis) such as collagens and fibronectins are also significantly upregulated. SPARC was localized to acinar cells where it increased in the vicinity of inflammatory foci. However, acinar expression of SPARC was lost during destruction of acinar cells. In human pancreatic specimens with chronic pancreatitis, SPARC exhibited a similar expression profile. During chronic inflammation and fibrosis in the WBN/Kob rat, inflammatory genes, growth factors, and structural genes exhibit a high increase of expression. A temporal profile including pre- and postinflammatory phases indicates a concurrent activation of inflammatory and fibrotic changes. Inflammation dependent expression of SPARC appears to be lost during acinar-to-duct metaplasia both in rat and human pancreas.
MicroRNA-127 modulates fetal lung development
Authors: Bhaskaran Manoj , Wang Yang , Zhang Honghao , Weng Tingting , Baviskar Pradyumna , Guo Yujie , Gou Deming , Liu Lin
Published: May 2009

MicroRNAs (miRNAs) are small endogenous RNAs and are widely regarded as one of the most important regulators of gene expression in both plants and animals. To define the roles of miRNAs in fetal lung development, we profiled the miRNA expression pattern during lung development with a miRNA microarray. We identified 21 miRNAs that showed significant changes in expression during lung development. These miRNAs were grouped into four distinct clusters based on their expression pattern. Cluster 1 contained miRNAs whose expression increased as development progressed, while clusters 2 and 3 showed the opposite trend of expression. miRNAs in cluster 4 including miRNA-127 (miR-127) had the highest expression at the late stage of fetal lung development. Quantitative real-time PCR validated the microarray results of six selected miRNAs. In situ hybridization demonstrated that miR-127 expression gradually shifted from mesenchymal cells to epithelial cells as development progressed. Overexpression of miR-127 in fetal lung organ culture significantly decreased the terminal bud count, increased terminal and internal bud sizes, and caused unevenness in bud sizes, indicating improper development. These findings suggest that miR-127 may have an important role in fetal lung development.
The Trifunctional Antibody Ertumaxomab Destroys Tumor Cells That Express Low Levels of Human Epidermal Growth Factor Receptor 2
Authors: Jäger Michael , Schoberth Alexandra , Ruf Peter , Hess Jürgen , Lindhofer Horst
Published: May 2009

Human epidermal growth factor receptor 2 (HER2/neu) is an important target for the treatment of the breast cancers in which it is overexpressed. However, no approved anti-HER2/neu therapy is available for the majority of breast cancer patients, who express HER2/neu at low levels (with scores of 1+ or 2+/fluorescence in situ hybridization–negative). The trifunctional antibody ertumaxomab targets HER2/neu, CD3, and activating Fcγ receptors. In presence of ertumaxomab, tri-cell complexes consisting of tumor cells, T cells, and accessory cells form to cause tumor cell lysis. In a phase I trial with metastatic breast cancer patients, ertumaxomab could be applied safely and resulted in radiographically confirmed clinical responses. In this study, we compare ertumaxomab- and trastuzumab-mediated killing of cancer cell lines that express HER2/neu at low and high levels. Under optimal conditions for trastuzumab-mediated destruction of HER2/neu-overexpressing cells, only ertumaxomab was able to mediate the elimination of tumor cell lines that express HER2/neu at low levels (1+). Ertumaxomab-mediated activity was accompanied by a Th1-based cytokine release, a unique mode of action of trifunctional antibodies. Competitive binding studies with trastuzumab and 520C9 mapped the binding site of ertumaxomab to the extracellular regions II and III of the HER2/neu ectodomain. This site is distinct from the binding site of trastuzumab, so that HER2/neu-expressing tumor cells can be eliminated by ertumaxomab in the presence of high amounts of trastuzumab. The ability of ertumaxomab to induce cytotoxicity against various tumor cell lines, including those with low HER2/neu antigen density, may provide a novel therapeutic option for breast cancer patients who are not eligible for trastuzumab treatment. [Cancer Res 2009;69(10):4270–6]
Host Genetic Variants in the Interleukin-6 Promoter Predict Poor Outcome in Patients with Estrogen Receptor-Positive, Node-Positive Breast Cancer
Authors: DeMichele Angela , Gray Robert , Horn Michelle , Chen Jinbo , Aplenc Richard , Vaughan William P. , Tallman Martin S.
Published: May 2009

Interleukin-6 modulates immune response, estrogen production, and growth pathways in breast cancer. We evaluated the effect of several common, functional interleukin-6 promoter variants in node-positive breast cancer patients enrolled on a multicenter, cooperative group, adjuvant chemotherapy trial to determine whether these variants were associated with clinical outcome overall and by estrogen receptor tumor phenotype. Genomic DNA and clinical data were collected from a clinical trial of adjuvant anthracycline-based chemotherapy followed by randomization to high-dose cyclophosphamide/thiotepa or observation (Intergroup Trial 0121). Genotyping for -174G>C (rs1800795), -597G>A (rs1800797), and -572G>C (rs1800796) was done by site-specific PCR and PyroSequencing, whereas the -373AnTn repeat was directly sequenced. Log-rank tests and Cox modeling were used to compare outcomes by genotype/haplotype and other factors. Three hundred forty-six patients (64% of trial) had corresponding genotype/clinical data available and did not differ from overall trial participants. After adjustment, patients with estrogen receptor-positive tumors and genotypes 597 GG or 174 GG had significantly worse disease-free survival [hazard ratio (HR), 1.6; P = 0.02 and HR, 1.71; P = 0.007, respectively], whereas the 373 8A12T repeat appeared to be protective (HR, 0.62; P = 0.02). The presence of at least one copy of the haplotype ([-597G, -572G, -373[10A/11T], -174G]) was associated with worse disease-free survival (HR, 1.46; P = 0.04). Kaplan-Meier plots show that all patients in this group relapsed by 24 months from diagnosis. This poor-risk haplotype was quite common overall (estimated frequency, 0.20) and twice as frequent among Blacks (estimated frequency, 0.41). [Cancer Res 2009;69(10):4184–91]
Intracellular Bacterial Vectors That Induce CD8+ T Cells with Similar Cytolytic Abilities but Disparate Memory Phenotypes Provide Contrasting Tumor Protection
Authors: Stark Felicity C. , Sad Subash , Krishnan Lakshmi
Published: May 2009

Induction of a functional CD8+ T-cell response is the important criterion for cancer vaccines, and it is unclear whether acute or chronic live vectors are better suited for cancer antigen delivery. We have evaluated the tumor protective ability of two recombinant vectors, Listeria monocytogenes (LM) and Salmonella typhimurium (ST), both expressing ovalbumin (OVA). Although both vectors induced a similar OVA-specific CD8+ T-cell response in the long term, LM-OVA induced mainly central-phenotype (TCM, CD44highCD62Lhigh), whereas ST-OVA induced mainly effector-phenotype (TEM, CD44highCD62Llow) cells. Both vectors induced functional OVA-specific CD8+ T cells that expressed IFN-γ and killed targets specifically in vivo. However, only LM-OVA–vaccinated mice were protected against B16-OVA tumors. This correlated to the ability of CD8+ T cells generated against LM-OVA, but not against ST-OVA, to produce interleukin 2 and exhibit profound homeostatic and antigen-induced proliferation in vivo. Furthermore, adoptive transfer of memory CD8+ T cells generated against LM-OVA (but not against ST-OVA) into recipient mice resulted in their trafficking to tumor-draining lymph nodes conferring protection. Although cytotoxicity and IFN-γ production are considered to be the principal functions of memory CD8+ T cells, the vaccine delivery strategy may also influence memory CD8+ T-cell quality, and ability to proliferate and traffic to tumors. Thus, for efficacy, cancer vaccines should be selected for their ability to induce self-renewing memory CD8+ T cells (CD44highIL-7RαhighCD62Lhigh) besides their effector functions. [Cancer Res 2009;69(10):4327–34]
Activation of Src by Protein Tyrosine Phosphatase 1B Is Required for ErbB2 Transformation of Human Breast Epithelial Cells
Authors: Arias-Romero Luis E. , Saha Sayanti , Villamar-Cruz Olga , Yip Shu-Chin , Ethier Stephen P. , Zhang Zhong-Yin , Chernoff Jonathan
Published: May 2009

Protein tyrosine phosphatase (PTP) 1B plays a major role in inhibiting signaling from the insulin and leptin receptors. Recently, PTP1B was found to have an unexpected positive role in ErbB2 signaling in a mouse model of breast cancer, but the mechanism underlying this effect has been unclear. Using human breast epithelial cells grown in a three-dimensional matrix, we found that PTP1B, but not the closely related enzyme T-cell PTP, is required for ErbB2 transformation in vitro. Activation of ErbB2, but not ErbB1, increases PTP1B expression, and increased expression of PTP1B activates Src and induces a Src-dependent transformed phenotype. These findings identify a molecular mechanism by which PTP1B links an important oncogenic receptor tyrosine kinase to signaling pathways that promote aberrant cell division and survival in human breast epithelial cells. [Cancer Res 2009;69(11):4582–8]
Cyclophosphamide Augments Antitumor Immunity: Studies in an Autochthonous Prostate Cancer Model
Authors: Wada Satoshi , Yoshimura Kiyoshi , Hipkiss Edward L. , Harris Tim J. , Yen Hung-Rong , Goldberg Monica V. , Grosso Joseph F. , Getnet Derese , Demarzo Angelo M. , Netto George J. , Anders Robert , Pardoll Drew M. , Drake Charles G.
Published: May 2009

To study the immune response to prostate cancer, we developed an autochthonous animal model based on the transgenic adenocarcinoma of the mouse prostate (TRAMP) mouse in which spontaneously developing tumors express influenza hemagglutinin as a unique, tumor-associated antigen. Our prior studies in these animals showed immunologic tolerance to hemagglutinin, mirroring the clinical situation in patients with cancer who are generally nonresponsive to their disease. We used this physiologically relevant animal model to assess the immunomodulatory effects of cyclophosphamide when administered in combination with an allogeneic, cell-based granulocyte-macrophage colony-stimulating factor–secreting cancer immunotherapy. Through adoptive transfer of prostate/prostate cancer–specific CD8 T cells as well as through studies of the endogenous T-cell repertoire, we found that cyclophosphamide induced a marked augmentation of the antitumor immune response. This effect was strongly dependent on both the dose and the timing of cyclophosphamide administration. Mechanistic studies showed that immune augmentation by cyclophosphamide was associated with a transient depletion of regulatory T cells in the tumor draining lymph nodes but not in the peripheral circulation. Interestingly, we also noted effects on dendritic cell phenotype; low-dose cyclophosphamide was associated with increased expression of dendritic cell maturation markers. Taken together, these data clarify the dose, timing, and mechanism of action by which immunomodulatory cyclophosphamide can be translated to a clinical setting in a combinatorial cancer treatment strategy. [Cancer Res 2009;69(10):4309–18]
KLF6-SV1 Is a Novel Antiapoptotic Protein That Targets the BH3-Only Protein NOXA for Degradation and Whose Inhibition Extends Survival in an Ovarian Cancer Model
Authors: DiFeo Analisa , Huang Fei , Sangodkar Jaya , Terzo Esteban A. , Leake Devin , Narla Goutham , Martignetti John A.
Published: May 2009

Defects in apoptosis are not only a hallmark of cancer initiation and progression but can also underlie the development of chemoresistance. How the tightly regulated cascade of protein-protein interactions between members of three competing protein families regulating the apoptotic cascade is subverted in tumor cells is incompletely understood. Here, we show that KLF6-SV1, whose overexpression is associated with poor survival in several different cancers and is an alternatively spliced isoform of the Krüppel-like tumor suppressor KLF6, is a critical prosurvival/antiapoptotic protein. KLF6-SV1 binds the proapoptotic BH3-only protein NOXA, which results in their mutual HDM2-dependent degradation. In turn, this increases the intracellular concentration of the prosurvival binding partner of NOXA, Mcl-1, and effectively blocks apoptosis. In an ovarian cancer model, systemically delivered small interfering RNA against KLF6-SV1 induces spontaneous apoptosis of tumor cells, decreases tumor burden, and restores cisplatin sensitivity in vivo. Moreover, i.p. delivery of siKLF6-SV1 RNA halts ovarian tumor progression and improves median and overall survival (progression-free for >15 months; P < 0.0002) in mice in a dose-dependent manner. Thus, KLF6-SV1 represents a novel regulator of protein interactions in the apoptotic cascade and a therapeutically targetable control point. [Cancer Res 2009;69(11):4733–41]
Lack of T-Cell Receptor–Induced Signaling Is Crucial for CD95 Ligand Up-regulation and Protects Cutaneous T-Cell Lymphoma Cells from Activation-Induced Cell Death
Authors: Klemke Claus-Detlev , Brenner Dirk , Weiβ Eva-Maria , Schmidt Marc , Leverkus Martin , Gülow Karsten , Krammer Peter H.
Published: May 2009

Restimulation of previously activated T cells via the T-cell receptor (TCR) leads to activation-induced cell death (AICD), which is, at least in part, dependent on the death receptor CD95 (APO-1, FAS) and its natural ligand (CD95L). Here, we characterize cutaneous T-cell lymphoma (CTCL) cells (CTCL tumor cell lines and primary CTCL tumor cells from CTCL patients) as AICD resistant. We show that CTCL cells have elevated levels of the CD95-inhibitory protein cFLIP. However, cFLIP is not responsible for CTCL AICD resistance. Instead, our data suggest that reduced TCR-proximal signaling in CTCL cells is responsible for the observed AICD resistance. CTCL cells exhibit no PLC-γ1 activity, resulting in an impaired Ca2+release and reduced generation of reactive oxygen species upon TCR stimulation. Ca2+ and ROS production are crucial for up-regulation of CD95L and reconstitution of both signals resulted in AICD sensitivity of CTCL cells. In accordance with these data, CTCL tumor cells from patients with Sézary syndrome do not up-regulate CD95L upon TCR-stimulation and are therefore resistant to AICD. These results show a novel mechanism of AICD resistance in CTCL that could have future therapeutic implications to overcome apoptosis resistance in CTCL patients. [Cancer Res 2009;69(10):4175–83]
Mesenchymal Stem Cell Delivery of TRAIL Can Eliminate Metastatic Cancer
Authors: Loebinger Michael R. , Eddaoudi Ayad , Davies Derek , Janes Sam M.
Published: May 2009

Cancer is a leading cause of mortality throughout the world and new treatments are urgently needed. Recent studies suggest that bone marrow–derived mesenchymal stem cells (MSC) home to and incorporate within tumor tissue. We hypothesized that MSCs engineered to produce and deliver tumor necrosis factor–related apoptosis-inducing ligand (TRAIL), a transmembrane protein that causes selective apoptosis of tumor cells, would home to and kill cancer cells in a lung metastatic cancer model. Human MSCs were transduced with TRAIL and the IRES-eGFP reporter gene under the control of a tetracycline promoter using a lentiviral vector. Transduced and activated MSCs caused lung (A549), breast (MDAMB231), squamous (H357), and cervical (Hela) cancer cell apoptosis and death in coculture experiments. Subcutaneous xenograft experiments confirmed that directly delivered TRAIL-expressing MSCs were able to significantly reduce tumor growth [0.12 cm3 (0.04-0.21) versus 0.66 cm3 (0.21-1.11); P < 0.001]. We then found, using a pulmonary metastasis model, systemically delivered MSCs localized to lung metastases and the controlled local delivery of TRAIL completely cleared the metastatic disease in 38% of mice compared with 0% of controls (P < 0.05). This is the first study to show a significant reduction in metastatic tumor burden with frequent eradication of metastases using inducible TRAIL-expressing MSCs. This has a wide potential therapeutic role, which includes the treatment of both primary tumors and their metastases, possibly as an adjuvant therapy in clearing micrometastatic disease following primary tumor resection. [Cancer Res 2009;69(10):4134–42]
The Mechanical Rigidity of the Extracellular Matrix Regulates the Structure, Motility, and Proliferation of Glioma Cells
Authors: Ulrich Theresa A. , de Juan Pardo Elena M. , Kumar Sanjay
Published: May 2009

Glioblastoma multiforme (GBM) is a malignant astrocytoma of the central nervous system associated with a median survival time of 15 months, even with aggressive therapy. This rapid progression is due in part to diffuse infiltration of single tumor cells into the brain parenchyma, which is thought to involve aberrant interactions between tumor cells and the extracellular matrix (ECM). Here, we test the hypothesis that mechanical cues from the ECM contribute to key tumor cell properties relevant to invasion. We cultured a series of glioma cell lines (U373-MG, U87-MG, U251-MG, SNB19, C6) on fibronectin-coated polymeric ECM substrates of defined mechanical rigidity and investigated the role of ECM rigidity in regulating tumor cell structure, migration, and proliferation. On highly rigid ECMs, tumor cells spread extensively, form prominent stress fibers and mature focal adhesions, and migrate rapidly. As ECM rigidity is lowered to values comparable with normal brain tissue, tumor cells appear rounded and fail to productively migrate. Remarkably, cell proliferation is also strongly regulated by ECM rigidity, with cells dividing much more rapidly on rigid than on compliant ECMs. Pharmacologic inhibition of nonmuscle myosin II–based contractility blunts this rigidity-sensitivity and rescues cell motility on highly compliant substrates. Collectively, our results provide support for a novel model in which ECM rigidity provides a transformative, microenvironmental cue that acts through actomyosin contractility to regulate the invasive properties of GBM tumor cells. [Cancer Res 2009;69(10):4167–74]
MicroRNA-21 modulates biological functions of pancreatic cancer cells including their proliferation, invasion, and chemoresistance
Authors: Moriyama Taiki , Ohuchida Kenoki , Mizumoto Kazuhiro , Yu Jun , Sato Norihiro , Nabae Toshinaga , Takahata Shunichi , Toma Hiroki , Nagai Eishi , Tanaka Masao
Published: May 2009

Due to the poor prognosis of pancreatic cancer, novel diagnostic modalities for early diagnosis and new therapeutic strategy are urgently needed. Recently, microRNA-21 (miR-21) was reported to be strongly overexpressed in pancreatic cancer as well as in other solid cancers. We investigated the functional roles of miR-21, which have not been fully elucidated in pancreatic cancer. miR-21 expression was assessed in pancreatic cancer cell lines (14 cancer cell lines, primary cultures of normal pancreatic epithelial cells and fibroblasts, and a human normal pancreatic ductal epithelial cell line) and pancreatic tissue samples (25 cancer tissues and 25 normal tissues) by quantitative real-time reverse transcription-PCR amplification. Moreover, we investigated the proliferation, invasion, and chemoresistance of pancreatic cancer cells transfected with miR-21 precursor or inhibitor. miR-21 was markedly overexpressed in pancreatic cancer cells compared with nonmalignant cells, and miR-21 in cancer tissues was much higher than in nonmalignant tissues. The cancer cells transfected with the miR-21 precursor showed significantly increased proliferation, Matrigel invasion, and chemoresistance for gemcitabine compared with the control cells. In contrast, inhibition of miR-21 decreased proliferation, Matrigel invasion, and chemoresistance for gemcitabine. Moreover, miR-21 positively correlated with the mRNA expression of invasion-related genes, matrix metalloproteinase-2 and -9, and vascular endothelial growth factor. These data suggest that miR-21 expression is increased in pancreatic cancer cells and that miR-21 contributes to the cell proliferation, invasion, and chemoresistance of pancreatic cancer.[Mol Cancer Ther 2009;8(5):1067–74]
The nonsteroidal anti-inflammatory drug tolfenamic acid inhibits BT474 and SKBR3 breast cancer cell and tumor growth by repressing erbB2 expression
Authors: Liu Xinyi , Abdelrahim Maen , Abudayyeh Ala , Lei Ping , Safe Stephen
Published: May 2009

Tolfenamic acid (TA) is a nonsteroidal anti-inflammatory drug that inhibits pancreatic cancer cell and tumor growth through decreasing expression of specificity protein (Sp) transcription factors. TA also inhibits growth of erbB2-overexpressing BT474 and SKBR3 breast cancer cells; however, in contrast to pancreatic cancer cells, TA induced down-regulation of erbB2 but not Sp proteins. TA-induced erbB2 down-regulation was accompanied by decreased erbB2-dependent kinase activities, induction of p27, and decreased expression of cyclin D1. TA also decreased erbB2 mRNA expression and promoter activity, and this was due to decreased mRNA stability in BT474 cells and, in both cell lines, TA decreased expression of the YY1 and AP-2 transcription factors required for basal erbB2 expression. In addition, TA also inhibited tumor growth in athymic nude mice in which BT474 cells were injected into the mammary fat pad. TA represents a novel and promising new anticancer drug that targets erbB2 by decreasing transcription of this oncogene. [Mol Cancer Ther 2009;8(5):OF1–11]
The Human Host Defense Peptide LL-37 Induces Apoptosis in a Calpain- and Apoptosis-Inducing Factor–Dependent Manner Involving Bax Activity
Authors: Mader Jamie S. , Mookherjee Neeloffer , Hancock Robert E.W. , Bleackley R. Chris
Published: May 2009

LL-37 is a human cationic host defense peptide (antimicrobial peptide) belonging to the cathelicidin family of peptides. In this study, LL-37 was shown to kill Jurkat T leukemia cells via apoptosis. A loss of mitochondrial membrane potential, DNA fragmentation, and phosphatidylserine externalization were detected following LL-37 exposure, whereas apoptosis was independent of caspase family members. The specific apoptotic pathway induced by LL-37 was defined through the utilization of Jurkat cells modified to express antiapoptotic proteins, as well as cells deficient in various proteins associated with apoptosis. Of interest, both Bcl-2–overexpressing cells and cells deficient in Bax and Bak proteins displayed a significant reduction in LL-37–induced apoptosis. In addition, Jurkat cells modified in the Fas receptor–associated pathway showed no reduction in apoptosis when exposed to LL-37. Analysis of the involvement of apoptosis-inducing factor (AIF) in LL-37–mediated apoptosis revealed that AIF transferred from the mitochondria to the nucleus of cells exposed to LL-37, where it may lead to large-scale DNA fragmentation and chromatin condensation. AIF knockdown analysis resulted in LL-37–resistant cells. This suggests that AIF is mandatory in LL-37–mediated killing. Lastly, chelation or inhibition of Ca2+ or calpains inhibited LL-37–mediated killing. Further analysis revealed that calpains were required for LL-37–mediated Bax translocation to mitochondria. Together, these data show that LL-37–induced apoptosis is mediated via the mitochondria-associated pathway in a caspase-independent and calpain- and AIF-dependent manner that involves Bax activation and translocation to mitochondria. (Mol Cancer Res 2009;7(5):689–702)
Host Deficiency in Vav2/3 Guanine Nucleotide Exchange Factors Impairs Tumor Growth, Survival, and Angiogenesis In vivo
Authors: Brantley-Sieders Dana M. , Zhuang Guanglei , Vaught David , Freeman Tanner , Hwang Yoonha , Hicks Donna , Chen Jin
Published: May 2009

Vav guanine nucleotide exchange factors modulate changes in cytoskeletal organization through activation of Rho, Rac, and Cdc42 small GTPases. Although Vav1 expression is restricted to the immune system, Vav2 and Vav3 are expressed in several tissues, including highly vascularized organs. Here, we provide the first evidence that Vav2 and Vav3 function within the tumor microenvironment to promote tumor growth, survival, and neovascularization. Host Vav2/3 deficiency reduced microvascular density, as well as tumor growth and/or survival, in transplanted B16 melanoma and Lewis lung carcinoma models in vivo. These defects were due in part to Vav2/3 deficiency in endothelial cells. Vav2/3-deficient endothelial cells displayed reduced migration in response to tumor cells in coculture migration assays, and failed to incorporate into tumor vessels and enhance tumor volume in tumor-endothelial cotransplantation experiments. These data suggest that Vav2/3 guanine nucleotide exchange factors play a critical role in host-mediated tumor progression and angiogenesis, particularly in tumor endothelium.(Mol Cancer Res 2009;7(5):615–23)
A Key Role for Early Growth Response-1 and Nuclear Factor-κB in Mediating and Maintaining GRO/CXCR2 Proliferative Signaling in Esophageal Cancer
Authors: Wang Bo , Khachigian Levon M. , Esau Luke , Birrer Michael J. , Zhao Xiaohang , Parker M. Iqbal , Hendricks Denver T.
Published: May 2009

Although early growth response-1 (EGR-1) has been shown as a key transcription factor in controlling cell growth, proliferation, differentiation, and angiogenesis, its role in the development of esophageal cancer is poorly understood despite the high frequency of this disease in many parts of the world. Here, immunohistochemistry showed that EGR-1 is overexpressed in 80% of esophageal tumor tissues examined. Furthermore, EGR-1 is constitutively expressed in all esophageal cancer cell lines analyzed. Esophageal squamous carcinoma WHCO1 cells stably transfected with EGR-1 short hairpin RNA displayed a 55% reduction in EGR-1 protein levels, 50% reduction in cell proliferation, a 50% reduction in cyclin-dependent kinase 4 levels, and a 2-fold induction in p27Kip1 levels associated with a G2-M cell cycle arrest. EGR-1 knockdown also caused a marked induction in IκBα expression, an effect also observed in GROβ RNA interference-expressing WHCO1 cells, because EGR-1 lies downstream of GRO/CXCR2 signaling. Furthermore, p65 mRNA levels were also reduced in cells treated with either short hairpin RNA EGR-1 or small interfering RNA EGR-1. Immunohistochemical analysis indicated that p65 is elevated in 78% (n = 61) of esophageal tumor sections analyzed. Moreover, nuclear factor-κB inhibition with either sodium salicylate or p65 RNA interference led to a significant reduction in GROα and GROβ expression. These results indicate that EGR-1 and nuclear factor-κB mediate GRO/CXCR2 proliferative signaling in esophageal cancer and may represent potential target molecules for therapeutic intervention.(Mol Cancer Res 2009;7(5):755–64)
Aurora-A Overexpression in Mouse Liver Causes p53-Dependent Premitotic Arrest during Liver Regeneration
Authors: Li Chao-Chin , Chu Hui-Yi , Yang Chu-Wen , Chou Chen-Kung , Tsai Ting-Fen
Published: May 2009

Aurora-A, a serine-threonine kinase, is frequently overexpressed in human cancers, including hepatocellular carcinoma. To study the phenotypic effects of Aurora-A overexpression on liver regeneration and tumorigenesis, we generated transgenic mice overexpressing human Aurora-A in the liver. The overexpression of Aurora-A after hepatectomy caused an earlier entry into S phase, a sustaining of DNA synthesis, and premitotic arrest in the regenerating liver. These regenerating transgenic livers show a relative increase in binuclear hepatocytes compared with regenerating wild-type livers; in addition, multipolar segregation and trinucleation could be observed only in the transgenic hepatocytes after hepatectomy. These results together suggest that defects accumulated after first round of the hepatocyte cell cycle and that there was a failure to some degree of cytokinesis. Interestingly, the p53-dependent checkpoint was activated by these abnormalities, indicating that p53 plays a crucial role during liver regeneration. Indeed, the premitotic arrest and abnormal cell death, mainly necrosis, caused by Aurora-A overexpression were genetically rescued by p53 knockout. However, trinucleation of hepatocytes remained in the regenerating livers of the transgenic mice with a p53 knockout background, indicating that the abnormal mitotic segregation and cytokinesis failure were p53 independent. Moreover, overexpression of Aurora-A in transgenic liver led to a low incidence (3.8%) of hepatic tumor formation after a long latency period. This transgenic mouse model provides a useful system that allows the study of the physiologic effects of Aurora-A on liver regeneration and the genetic pathways of Aurora-A–mediated tumorigenesis in liver.
Rationale and Design of the Prevention of Cerebrovascular and Cardiovascular Events of Ischemic Origin with Terutroban in Patients with a History of Ischemic Stroke or Transient Ischemic Attack (PERFORM) Study
Authors: Hennerici Michael G.
Published: May 2009

Background: One of the leading causes of mortality worldwide is ischemic stroke, which is a major contributor to neurological disability and dementia. Terutroban is a specific thromboxane A2 receptor antagonist with antithrombotic, antivasoconstrictive, and antiatherosclerotic properties, which make it a promising tool for secondary prevention of ischemic stroke. Methods and Results: The Prevention of Cerebrovascular and Cardiovascular Events of Ischemic Origin with Terutroban in Patients with a History of Ischemic Stroke or Transient Ischemic Attack (PERFORM) Study is an international, multicenter, randomized, double-blind, parallel-group study in patients aged ≥55 years who have suffered ischemic strokes (<3 months) or transient ischemic attacks (<8 days), and who are stable at inclusion with no intracranial hemorrhage or nonischemic neurological diseases. Patients are randomly allocated to terutroban (30 mg/day) or aspirin (100 mg/day). The primary efficacy end point is a composite of ischemic stroke (fatal or nonfatal), myocardial infarction (fatal or nonfatal), or other vascular death (excluding hemorrhagic death of any origin). Safety is evaluated by assessing hemorrhagic events. The first patient was randomized in February 2006 and more than 19,000 patients will be included. Conclusions: The PERFORM Study will explore the benefits of terutroban in secondary prevention of ischemic stroke. The study results are expected in 2011.
Interstitial Cells of Cajal in Abdominal Sepsis and Hypertension-Induced Ileus in Rats
Authors: Lou Zheng , Li Jie Shou
Published: May 2009

Purpose: To evaluate injury to the myenteric interstitial cells of Cajal (ICC-MY) and assess the role of ICC-MY in gastrointestinal motility in rat models of abdominal sepsis and intra-abdominal hypertension (IAH). Materials and Methods: Sprague-Dawley rats were divided into 4 groups; group 1: sham group; group 2: sepsis induced by cecal puncture and ligation; group 3: IAH created by placing a catheter into the abdominal cavity; group 4: sepsis and IAH induced simultaneously. Small intestinal segments were resected 24 h after surgery. Ileum sections stained with HE were assessed pathologically. The spontaneous mechanical activity was evaluated using the organ bath technique. The alterations in ICC-MY networks by immunohistochemical staining for c-Kit and the ultrastructural changes in ICC-MY by transmission electron microscopy were evaluated. Results: There were significant differences in the frequency and amplitude of the bowel segment contractions between groups 1, 2, 3 and 4. These changes were associated with lesions of ICC-MY networks and ultrastructure. Conclusions: Abdominal sepsis and IAH resulted in damage to ICC-MY networks, leading to disordered intestinal rhythmicity. The combination of sepsis and IAH causes far more serious injury than either sepsis or IAH alone.
Comparative Effects of Olmesartan and Azelnidipine on Atrial Structural Remodeling in Spontaneously Hypertensive Rats
Authors: Okamura Kazuki , Ito Masahiro , Tanaka Komei , Chinushi Masaomi , Adachi Takeshi , Mitsuma Wataru , Hirono Satoru , Nakazawa Mikio , Kodama Makoto , Aizawa Yoshifusa
Published: May 2009

The differential effects between olmesartan (OM), an angiotensin 2 type 1 receptor blocker (ARB), and azelnidipine (AZ), a calcium channel blocker (CCB), on atrial structural remodeling were studied in spontaneously hypertensive rats (SHR). Eight weeks after treatment, both OM and AZ decreased systolic blood pressure to similar levels. Histological analysis revealed that both OM and AZ had decreased the size of the atrial myocytes and interstitial fibrosis in the atrium, and that the effects of OM were greater than those of AZ. These beneficial effects of OM were associated with less atrial oxidative stress, as assessed by 3-nitrotyrosine staining, and less activation of Rac1, a regulatory component in NADPH oxidase. These results suggest that the ARB was more effective than the CCB in ameliorating atrial structural remodeling due to the suppression of oxidative stress.
Clinicopathological Characteristics and Outcome of Chinese Patients with Thrombotic Thrombocytopenic Purpura-Hemolytic Uremic Syndrome: A 9-Year Retrospective Study
Authors: Zhang Wen , Shi Hao , Ren Hong , Shen Ping-Yan , Pan Xiao-Xia , Li Xiao , Chen Yong-Xi , Xu Yao-Wen , Chen Xiao-Nong , Zhu Ping , Chen Nan
Published: May 2009

Background: The pathogenesis of thrombotic thrombocytopenic purpura-hemolytic uremic syndrome (TTP-HUS) is unclear and the prognosis is poor. Few studies have been published focusing on Chinese patients with TTP-HUS. We performed a retrospective study on the clinical characteristics and outcome of Chinese patients with TTP-HUS. Method: Patients with TTP-HUS, admitted to our hospital from 1998 to 2006, were retrospectively analyzed. Results: There were 26 females and 6 males in our study. Fifteen patients had systemic lupus erythematosus (SLE)-associated TTP-HUS; 2 had pregnancy-associated TTP-HUS; 1 had antiphospholipid syndrome-associated TTP-HUS; 2 had drug-associated TTP-HUS; 4 had malignant angionephrosclerosis- associated TTP-HUS; 3 had vasculitis-associated TTP-HUS, and the remaining 5 had idiopathic TTP-HUS. Twenty-six patients had acute kidney injury and 21 had nephrotic syndrome. Hypertension was found in 31 patients. For the treatment, 15 patients had plasmapheresis, 12 had continuous veno-venous hemodiafiltration and 14 had hemodialysis. Eighteen patients were treated with intravenous immunoglobulin. Corticosteroids were used in patients with idiopathic TTP-HUS. For the patients with SLE-associated TTP-HUS, corticosteroids and immunosuppressant were used. Outcome was poor: 6 patients died; 17 recovered from renal insufficiency; 5 progressed to chronic renal failure, and 4 were dependent on hemodialysis. Conclusions: Most of our patients had secondary TTP-HUS. SLE-associated TTP-HUS is the most common form of TTP-HUS. Early diagnosis and treatment can improve prognosis. An immunosuppressant together with corticosteroids could improve prognosis in some patients.