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New Molecular Targets (new + molecular_target)
Selected AbstractsMammalian target of rapamycin is activated in human gastric cancer and serves as a target for therapy in an experimental modelINTERNATIONAL JOURNAL OF CANCER, Issue 8 2007Sven A. Lang Abstract The mammalian target of rapamycin (mTOR) has become an interesting target for cancer therapy through its influence on oncogenic signals, which involve phosphatidylinositol-3-kinase and hypoxia-inducible factor-1, (HIF-1,). Since mTOR is an upstream regulator of HIF-1,, a key mediator of gastric cancer growth and angiogenesis, we investigated mTOR activation in human gastric adenocarcinoma specimens and determined whether rapamycin could inhibit gastric cancer growth in mice. Expression of phospho-mTOR was assessed by immunohistochemical analyses of human tissues. For in vitro studies, human gastric cancer cell lines were used to determine S6K1, 4E-BP-1 and HIF-1, activation and cancer cell motility upon rapamycin treatment. Effects of rapamycin on tumor growth and angiogenesis in vivo were assessed in both a subcutaneous tumor model and in an experimental model with orthotopically grown tumors. Mice received either rapamycin (0.5 mg/kg/day or 1.5 mg/kg/day) or diluent per intra-peritoneal injections. In addition, antiangiogenic effects were monitored in vivo using a dorsal-skin-fold chamber model. Immunohistochemical analyses showed strong expression of phospho-mTOR in 60% of intestinal- and 64% of diffuse-type human gastric adenocarcinomas. In vitro, rapamycin-treatment effectively blocked S6K1, 4E-BP-1 and HIF-1, activation, and significantly impaired tumor cell migration. In vivo, rapamycin-treatment led to significant inhibition of subcutaneous tumor growth, decreased CD31-positive vessel area and reduced tumor cell proliferation. Similar significant results were obtained in an orthotopic model of gastric cancer. In the dorsal-skin-fold chamber model, rapamycin-treatment significantly inhibited tumor vascularization in vivo. In conclusion, mTOR is frequently activated in human gastric cancer and represents a promising new molecular target for therapy. © 2007 Wiley-Liss, Inc. [source] Antiangiogenic and Chemopreventive Activities of Celecoxib in Oral Carcinoma Cell,,THE LARYNGOSCOPE, Issue 5 2002Zhi Wang MD Abstract Objectives Chemoprevention is a promising strategy to inhibit carcinoma before invasive tumors develop, but a new molecular target is desirable. Celecoxib is a newly developed cyclo-oxygenase (COX)-2 inhibitor with significantly less toxicity. The study was conducted to determine whether celecoxib is effective and safe in prevention of oral cancer. The antiangiogenic activity of celecoxib was studied to explore the potential mechanism involved. Study Design Randomized animal study. Methods The study consisted of two phases. In the phase 1, 10 mice were used to determine the efficacy and safety of celecoxib with intradermal inoculation with oral carcinoma cells. The 10 mice were equally divided into two groups 5 mice (30 inoculated sites) in each group to receive 1,500 parts per million (ppm) celecoxib mixed in with the diet or to eat a normal diet, respectively, for 21 days. In phase 2, 10 more mice were inoculated to determine the effect of celecoxib on angiogenesis. Five mice received 3,000 ppm celecoxib in the diet, with the other five mice as control animals. The antiangiogenic activity was evaluated by comparing the density of newly growing microvessels after the inoculation. Results The results indicated that celecoxib significantly delayed cell growth and reduced tumor volume. There was statistical significance in the quantity of new vasculature in the tumor sites between the two groups. No toxic effect was found by means of measurement of body weight loss and microscopic dissection of organs. Conclusions The study provided the first evidence to show the chemopreventive efficacy of celecoxib on oral cancer in a nude mouse model. Clinical trials are warranted to determine the efficacy in humans. [source] Early genomics of learning and memory: a reviewGENES, BRAIN AND BEHAVIOR, Issue 3 2006S. Paratore The characterization of the molecular mechanisms whereby our brain codes, stores and retrieves memories remains a fundamental puzzle in neuroscience. Despite the knowledge that memory storage involves gene induction, the identification and characterization of the effector genes has remained elusive. The completion of the Human Genome Project and a variety of new technologies are revolutionizing the way these mechanisms can be explored. This review will examine how a genomic approach can be used to dissect and analyze the complex dynamic interactions involved in gene regulation during learning and memory. This innovative approach is providing information on a new class of genes associated with learning and memory in health and disease and is elucidating new molecular targets and pathways whose pharmacological modulation may allow new therapeutic approaches for improving cognition. [source] Mouse models for human head and neck squamous cell carcinomasHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 10 2006Shi-Long Lu MD Abstract Mouse models of human cancer play an important role in understanding the mechanisms of carcinogenesis and have accelerated the search for finding new molecular targets for cancer therapy. However, genetically engineered mouse models for head and neck squamous cell carcinoma (HNSCC) have only recently overcome major technical obstacles and begun to be explored. Here we review the current progress in the development of mouse models for human HNSCC, with emphasis on conditional transgenic and knockout mouse models. These new models faithfully recapitulate human HNSCC at both the pathologic and molecular levels. These animal models will not only be useful to define the roles of specific genes in HNSCC development and progression but will also provide a unique tool for developing and testing new therapeutic approaches. © 2006 Wiley Periodicals, Inc. Head Neck, 2006 [source] A new era for small molecule screening: from new targets, such as JAK2 V617F, to complex cellular screensJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 2 2009Stefan N. ConstantinescuArticle first published online: 21 JAN 200 Traditionally reserved to research and development in pharmaceutical companies, screening of small molecule libraries is rapidly becoming an approach undertaken by academic laboratories. Novel cellular assays, sensitive systems to probe function, emerging new molecular targets are just some of the reasons explaining this shift. Targets of small molecules identified in cellular screens begin to be amenable to identification by elegant genetic approaches, such as probing toxicity of candidate small molecules on libraries of genetically modified yeast strains. Several new targets, such as JAK2 V617F, an activated JAK2 (Janus Kinase 2) mutant genetically associated with the majority of human myeloproliferative neoplasms, are being actively pursued. In this Review Series, we will learn how libraries of small molecules are harnessed to identify novel molecules, that alone or in combination, have the ability to alter cell fate, cell signalling, gene expression or response to extracellular cues. [source] Insight Into the Relationship Between Impulsivity and Substance Abuse From Studies Using Animal ModelsALCOHOLISM, Issue 8 2010Catharine A. Winstanley Drug use disorders are often accompanied by deficits in the capacity to efficiently process reward-related information and to monitor, suppress, or override reward-controlled behavior when goals are in conflict with aversive or immediate outcomes. This emerging deficit in behavioral flexibility and impulse control may be a central component of the progression to addiction, as behavior becomes increasingly driven by drugs and drug-associated cues at the expense of more advantageous activities. Understanding how neural mechanisms implicated in impulse control are affected by addictive drugs may therefore prove a useful strategy in the search for new treatment options. Animal models of impulsivity and addiction could make a significant contribution to this endeavor. Here, some of the more common behavioral paradigms used to measure different aspects of impulsivity across species are outlined, and the importance of the response to reward-paired cues in such paradigms is discussed. Naturally occurring differences in forms of impulsivity have been found to be predictive of future drug self-administration, but drug exposure can also increase impulsive responding. Such data are in keeping with the suggestion that impulsivity may contribute to multiple stages within the spiral of addiction. From a neurobiological perspective, converging evidence from rat, monkey, and human studies suggest that compromised functioning within the orbitofrontal cortex may critically contribute to the cognitive sequelae of drug abuse. Changes in gene transcription and protein expression within this region may provide insight into the mechanism underlying drug-induced cortical hypofunction, reflecting new molecular targets for the treatment of uncontrolled drug-seeking and drug-taking behavior. [source] Modern strategies to identify new molecular targets for the treatment of liver diseases: The promising role of Proteomics and Redox Proteomics investigationsPROTEOMICS - CLINICAL APPLICATIONS, Issue 2 2009Andrea Scaloni Dr. Abstract Oxidative stress, due to an imbalance between the generation of ROS and the antioxidant defense capacity of the cell, is a major pathogenetic event occurring in several liver diseases, ranging from metabolic to proliferative. Main sources of ROS are represented by mitochondria and cytochrome P450 enzymes in the hepatocytes, Küppfer cells, and neutrophils. Oxidative stress affects major cellular components including lipids, DNA, and proteins. Through modulation of protein structure/function, ROS can influence gene expression profile by affecting intracellular signal transduction pathways. While several enzymatic and nonenzymatic markers of chronic oxidative stress are well known in liver, early protein targets of oxidative injury are yet poorly defined. Identification of these biomarkers will enable early detection of liver diseases and will allow monitoring the degree of liver damage, the response to pharmacological therapies, and the development of new therapeutic approaches. In the era of molecular medicine, new proteomic methodologies promise to establish a relationship between pathological hallmarks of the disease and protein structural/functional modifications, thus allowing a better understanding and a more rational therapy on liver disorders. Purpose of this review is to critically analyze the application of proteomic and redox proteomic approaches to the study of oxidative stress-linked liver diseases. [source] Bicalutamide inhibits androgen-mediated adhesion of prostate cancer cells exposed to ionizing radiationTHE PROSTATE, Issue 16 2008Tao Wang Abstract Background Cell adhesion plays an important role in proliferation, metastasis, and tumor growth and may represent a potential vulnerability in treatment of prostate cancer patients. Bicalutamide (Casodex) has been used as an anti-androgen agent for prostate cancer patients during hormone ablation therapy. This study focuses on the effect of Bicalutamide on cell adhesion to fibronectin (FN) in prostate cancer cells. Methods Androgen,dependent LNCaP prostate cancer cells were stimulated with androgen before being irradiated with doses of 0, 5, 10, or 15 Gy. Cell adhesion to fibronectin was then measured to ascertain androgen's role in integrin mediated prostate cancer cell adhesion. Flow cytometry was used to analyze surface expression of integrin subtypes in LNCaP cells. Results LNCaP cell adhesion to FN was significantly increased by stimulation with androgen when treated with 10 or 15 Gy ionizing radiations but not at 0 or 5 Gy. This increase was inhibited by treatment with Bicalutamide. LNCaP cells exposed to high dose radiation showed an increased expression of ,V and ,1 integrins in response to androgen treatment while Bicalutamide abolished this effect. Conclusions Our data show that Bicalutamide inhibits the effect of androgen on cell adhesion to FN through changes of integrin subtypes in cells given high dose radiation. This suggests new molecular targets and possible treatment strategies for prostate cancer patients to improve the outcome during hormone ablation therapy and radiation therapy. Prostate © 2008 Wiley-Liss, Inc. [source] Therapeutic effects of interleukin-6 blockade in a murine model of polymyositis that does not require interleukin-17AARTHRITIS & RHEUMATISM, Issue 8 2009Naoko Okiyama Objective To explore new molecular targets in the treatment of polymyositis (PM) by examining a recently established murine model of PM, C protein,induced myositis (CIM), for involvement of an interleukin-6 (IL-6)/IL-17A pathway. Methods CIM was induced by immunizing wild-type mice as well as IL-6,null and IL-17A,null C57BL/6 mice with recombinant mouse skeletal C protein fragments. Some mice were treated with anti,IL-6 receptor (anti,IL-6R) monoclonal antibodies or control antibodies. Muscle tissue samples were examined histologically and immunohistochemically. Results The syngeneic C protein fragments successfully induced inflammation in the skeletal muscles of wild-type mice. IL-6 was expressed by mononuclear cells, especially in macrophages, infiltrating in the muscles. IL-6,null mice developed myositis with significantly lower incidence and milder severity than wild-type mice. In contrast, IL-17A,null mice were as susceptible to CIM as wild-type mice. Intraperitoneal administration of anti,IL-6R monoclonal antibodies, but not of control monoclonal antibodies, ameliorated CIM both preventively and therapeutically. Conclusion Our findings indicate that IL-6 is critically involved in the development of CIM. Although many other autoimmune models require IL-6 for differentiation of pathogenic T cells producing IL-17A, IL-17A was dispensable in CIM. Nevertheless, treatment with anti,IL-6R antibodies was effective. IL-6 blockade is potentially a new approach to the treatment of autoimmune myositis, via processes distinct from interference in the IL-6/IL-17A pathway. [source] Modulation of synaptic plasticity by stress and antidepressantsBIPOLAR DISORDERS, Issue 3 2002Maurizio Popoli Recent preclinical and clinical studies have shown that mechanisms underlying neuronal plasticity and survival are involved in both the outcome of stressful experiences and the action of antidepressants. Whereas most antidepressants predominantly affect the brain levels of monoamine neurotransmitters, it is increasingly appreciated that they also modulate neurotransmission at synapses using the neurotransmitter glutamate (the most abundant in the brain). In the hippocampus, a main area of the limbic system involved in cognitive functions as well as attention and affect, specific molecules enriched at glutamatergic synapses mediate major changes in synaptic plasticity induced by stress paradigms or antidepressant treatments. We analyze here the modifications induced by stress or antidepressants in the strength of synaptic transmission in hippocampus, and the molecular modifications induced by antidepressants in two main mediators of synaptic plasticity: the N -methyl- D -aspartate (NMDA) receptor complex for glutamate and the Ca2+/calmodulin-dependent protein kinase II (CaM kinase II). Both stress and antidepressants induce alterations in long-term potentiation of hippocampal glutamatergic synapses, which may be partly accounted for by the influence of environmental or drug-induced stimulation of monoaminergic pathways projecting to the hippocampus. In the course of antidepressant treatments significant changes have been described in both the NMDA receptor and CaM kinase II, which may account for the physiological changes observed. A central role in these synaptic changes is exerted by brain-derived neurotrophic factor (BDNF), which modulates both synaptic plasticity and its molecular mediators, as well as inducing morphological synaptic changes. The role of these molecular effectors in synaptic plasticity is discussed in relation to the action of antidepressants and the search for new molecular targets of drug action in the therapy of mood disorders. [source] | |||||||||||||