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Alterations of Epigenetics and MicroRNAs in Cancer and Cancer Stem Cell

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889193455 Year: Pages: 79 DOI: 10.3389/978-2-88919-345-5 Language: English
Publisher: Frontiers Media SA
Subject: Biology --- Genetics --- Science (General)
Added to DOAB on : 2016-03-10 08:14:32
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Studies have shown that alterations of epigenetics and microRNAs (miRNAs) play critical roles in the initiation and progression of human cancer. Epigenetic silencing of tumor suppressor genes in cancer cells is generally mediated by DNA hypermethylation of CpG island promoter and histone modification such as methylation of histone H3 lysine 9 (H3K9) and tri-methylation of H3K27. MiRNAs are small non-coding RNAs that regulate expression of various target genes. Specific miRNAs are aberrantly expressed and play roles as tumor suppressors or oncogenes during carcinogenesis. Important tumor suppressor miRNAs are silenced by epigenetic alterations, resulting in activation of target oncogenes in human malignancies. Stem cells have the ability to perpetuate themselves through self-renewal and to generate mature cells of various tissues through differentiation. Accumulating evidence suggests that a subpopulation of cancer cells with distinct stem-like properties is responsible for tumor initiation, invasive growth, and metastasis formation, which is defined as cancer stem cells. Cancer stem cells are considered to be resistant to conventional chemotherapy and radiation therapy, suggesting that these cells are important targets of cancer therapy. DNA methylation, histone modification and miRNAs may be deeply involved in stem-like properties in cancer cells. Restoring the expression of tumor suppressor genes and miRNAs by chromatin modifying drugs may be a promising therapeutic approach for cancer stem cells. In this Research Topic, we discuss about alterations of epigenetics and miRNAs in cancer and cancer stem cell and understand the molecular mechanism underlying the formation of cancer stem cell, which may provide a novel insight for treatment of refractory cancer.

Targeting PI3K/mTOR signaling in cancer

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889192441 Year: Pages: 93 DOI: 10.3389/978-2-88919-244-1 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Biology --- Medicine (General) --- Oncology
Added to DOAB on : 2015-11-16 15:44:59
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The phosphatidylinositol 3-kinase (PI3K)/mTOR pathway integrates signals from growth factors with nutrient signals and other conditions and controls multiple cell responses, including proliferation, survival and metabolism. Deregulation of the PI3K pathway has been extensively investigated in connection to cancer. Somatic or inherited mutations frequently occur in tumor suppressor genes (PTEN, TSC1/2, LKB1) and oncogenes (PIK3CA, PIK3R1, AKT) in the PI3K/mTOR pathway. The fact that the PI3K/mTOR pathway is deregulated in a large number of human malignancies, and its importance for different cellular responses, makes it an attractive drug target. Pharmacological PI3K inhibitors have played a very important role in studying cellular responses involving these enzymes. Currently, a wide range of selective PI3K inhibitors have been tested in preclinical studies and some have entered clinical trials in oncology. Rapamycin and its analogs targeting mTOR are effective in many preclinical cancer models. Although rapalogs are approved for the treatment of some cancers, their efficacy in clinical trials remains the subject of debate. Due to the complexity of the PI3K/mTOR signaling pathway, developing an effective anti-cancer therapy remains a challenge. The biggest challenge in curing cancer patients with various signaling pathway abnormalities is to target multiple components of different signal transduction pathways with mechanism-based combinatorial treatments.

The immunology of cellular stress proteins

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889193257 Year: Pages: 89 DOI: 10.3389/978-2-88919-325-7 Language: English
Publisher: Frontiers Media SA
Subject: Allergy and Immunology --- Medicine (General)
Added to DOAB on : 2016-03-10 08:14:32
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Stress proteins or heat-shock proteins (HSP) are evolutionary conserved proteins present in every prokaryotic and eukaryotic cell. Their main function is to protect cells and proteins from damage under stressful circumstances. The latter circumstances do include the cell and protein damaging effects of inflammation. The discovery of mycobacterial HSP60 being a critical antigen in the model of adjuvant arthritis, has led to studies that showed the immuno-dominance of microbial HSP60 and the potential of the microbial HSP induced repertoire of antibodies and T cells to cross-recognize the self-HSP homologues of stressed cells. Since then, the research in the immunology of stress proteins started to comprise a widening spectrum of topics with potential medical relevance. Interestingly, since stress proteins have their activities in both innate and adaptive immunity, they are key elements in the cross-roads between both arms of the immune system. Stress proteins or HSP can be considered as functional 'biomarkers' of inflammation. They are up-regulated locally during inflammation and interestingly, they seem to function as targets for anti-inflammatory regulatory T cells. In experimental models of autoimmunity, mainly arthritis, administration of HSP peptides have been shown to suppress disease. First clinical trials have shown the anti-inflammatory nature of T cell responses to Hsp. In type I diabetes and in rheumatoid arthritis, parenteral and oral administration of Hsp peptides were shown to induce a bias in pro-inflammatory T cells, switching them in the direction of regulatory cytokine production (IL4, IL5 and IL10). In addition a raised level of a marker of natural T regulatory cells, the transcription factor FoxP3, was noted in the RA trial. Other inflammatory diseases or diseases with inflammatory components which feature the immune imprint of the up-regulated Hsp are atherosclerosis, inflammatory bowel diseases, multiple sclerosis and atopic diseases such atopic dermatitis and allergic asthma.

Targeting thyroid cancer microenvironment and epigenetic signalling: new frontiers in cancer endocrinology basic and clinical research

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889192403 Year: Pages: 131 DOI: 10.3389/978-2-88919-240-3 Language: English
Publisher: Frontiers Media SA
Subject: Medicine (General) --- Internal medicine --- Oncology
Added to DOAB on : 2015-11-16 15:44:59
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This Research Topic is devoted to the understanding of molecular mechanisms of Human Thyroid Cancers. Original research describing functional studies of genetic mutations that shed novel insights into the aetiology and pathogenesis of these cancers, as well as angiogenesis and tumor microenvironment, mouse models studies that describe mechanisms or novel potential therapeutic targets and biomarkers for these endocrine cancers are presented. Scopes: The scope of this Research Topic was to cover the entire field of thyroid cancers: the main focus of this topic is translational, with an emphasis on bench to bedside research. Experimental, pre-clinical and clinical research addressing the following aspects is included in this Research Topic: 1) Investigation of specific molecular patterns of thyroid tumorigenesis, which could allow the development of new directions in the field of pharmacotherapy research; 2) Emphasis on animal studies (preclinical models of human anaplastic thyroid cancers) for the validation of biomarkers with the potential to lead to clinical trials, and studies of targetable mechanisms of oncogenesis, progression of these malignancies, tumor microenvironment and extracellular matrix, and metastatic disease; 3) Assessment of biomarkers to predict the potential response or resistance to drug treatment (targeted cancer therapies) or to guide the follow-up of treated patients; 4) Investigation of new laboratory molecular tests (e.g. molecular techniques and applications of thyroid fine-needle aspiration biopsy) to translate in the clinical practice; In summary, specific areas of interest include: thyroid cancer genetics; genome-wide analysis; clinical and translational research; orthotopic mouse models of metastatic thyroid carcinoma; tumor microenvironment; epigenetic; biological insights of personalized medicine; novel applications of bioinformatics; large scale molecular characterization of tumors; diagnostic or prognostic biomarkers; endocrine pathology studies; thyroid fine-needle aspiration.

Vitamin C and Human Health

ISBN: 9783906980614 9783906980621 Year: Pages: 236 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Added to DOAB on : 2015-01-12 11:52:06
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Ascorbic acid is a small, simple, water soluble molecule, synthesised by most plants and animals, with the exception of humans and some animal species due to mutations in the gene encoding the terminal enzyme in the biosynthetic pathway. For humans, it is thus a vitamin (vitamin C) that must be obtained from the diet, with complete deficiency resulting in the fatal disease scurvy. Many functions have been attributed to this fascinating molecule and, despite nearly 90 years of research since its discovery, new roles are still being uncovered, including recent discoveries that it acts as a regulator of epigenetic marks and transcription factors (1). In this volume we begin with a review by Michels and Frei on specific factors that need to be taken into consideration when carrying out vitamin C research. Translational research normally comprises a progression from in vitro/cell culture studies to animal models and finally to clinical trials. At each of these stages, there are requirements specific to vitamin C research that need to be integrated into study designs and this review describes these in detail. [...]

Tumor Cell/Dendritic Cell Interactions and the Influence of Tumors on Dendritic Cell-mediated Anti-Tumor Immune Responses and Dendritic Cell-Based Tumor Immunotherapies

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889192458 Year: Pages: 160 DOI: 10.3389/978-2-88919-245-8 Language: English
Publisher: Frontiers Media SA
Subject: Medicine (General) --- Allergy and Immunology --- Oncology
Added to DOAB on : 2015-11-16 15:44:59
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Significant efforts over the last two decades have been made to better understand the factors that control DC maturation and activation and the impact of these processes on overall host immunity. In addition to the well-characterized role of DC in the induction of immunity to pathogens, a role for these cells as critical regulators of anti-tumor immune responses has more recently become apparent. These findings have generated interest in understanding how tumor/DC interactions impact the quality of anti-tumor immune responses, and they have contributed to increased enthusiasm for a variety of DC-based cancer immunotherapies. Such strategies have included DNA- or peptide-based vaccines that involve uptake and processing of tumor antigens by endogenous DC in cancer patients or the administration of tumor antigen-loaded exogenous DC-based vaccines. Additionally, many adjuvant, cytokine, and monoclonal antibody therapies aim either to enhance the immunostimulatory capacity of endogenous DC or to supplement the activity of these cells by targeting costimulatory receptors on T cells. Despite the promise of such therapeutic approaches for cancer treatment, their success is often limited, and much remains to be understood about how tumors influence DC function and the quality of DC-mediated immune responses. Tumor/DC interactions have therefore become an increasingly active area of investigation, and many studies have described effects of tumors on DC phenotype and function that include an accumulation of immature DC within tumors, tumor-altered differentiation of DC precursors into myeloid-derived suppressor cells, and the generation of tumor-associated DC with immunoregulatory properties. As this field moves forward, it will be important to gain mechanistic insights into the basis for both tumor-mediated DC dysfunction as well as the induction of either suboptimal or immunosuppressive adaptive anti-tumor immune responses by tumor-associated DC. Progress in these areas of tumor immunology will greatly improve our understanding of the factors that contribute to effective DC-mediated anti-tumor immune control versus DC-associated anti-tumor immune dysfunction and subsequent tumor immune escape. Such information is vital for improving current and developing novel immunotherapeutic strategies for interfering with tumor-associated DC dysfunction and enhancing the functional quality of endogenous DC in cancer patients as well as the efficacy of exogenous DC-based anti-tumor vaccines. The articles contained within this special issue highlight these important topics and bring focus not only to our current understanding of tumor/DC interactions but also to major areas of investigation that remain ongoing in this field.

Cancer Immunotherapy & Immuno-monitoring: Mechanism, Treatment, Diagnosis, and Emerging Tools

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889193806 Year: Pages: 97 DOI: 10.3389/978-2-88919-380-6 Language: English
Publisher: Frontiers Media SA
Subject: Oncology --- Medicine (General)
Added to DOAB on : 2015-12-03 13:02:24
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In the past decade, significant progresses have taken place in the field of cancer immunotherapy. Tumor-targeting immunotherapies are being developed for most human cancers, including melanoma, prostate cancer, glioblastoma, sarcoma, lung carcinoma and hepatocellular carcinoma. The FDA has approved multiple molecular immunotherapeutics, such as Ipilimumab; cellular immunotherapies (e.g. adoptive cell transfer) are being tested in phase II/III clinical trials. Immunotherapetics has evolved into a sophisticated field: Multimodal therapeutic regimens are administrated to induce focused responses, curtail side- effects and improve therapeutic efficacy. The lack of effective clinical assessment tools remains a major challenge. Because of the intricacy of antitumor response, it is essential to scrutinize individual tumor-targeting immune cells and their functions at the finest details - molecules. In this regard, flow cytometry analysis modernized hematology and allows characterization of surface molecular signature on individual cells. More recently, microchip technologies and new variations of cytometry have enormously expanded the spectrum, throughout and multiplexity of single cell analysis. Nowadays, tens of millions of readouts can be generated through the course of a cancer immunotherapy to monitor the abundance, phenotype and a myriad of effector functions of single immune cells. At the same time, big data analytics and data mining methodologies have been adapted to achieve sensible diagnostic interpretations. Such a marriage of technology and analytics opens the door for informative point-of-care assessment of therapeutic efficacy and ensures timely therapeutic decisions. The new generation of personalized clinical diagnostics will revolutionize healthcare in the years to come.

Advances in Systems Immunology and Cancer

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889193134 Year: Pages: 108 DOI: 10.3389/978-2-88919-313-4 Language: English
Publisher: Frontiers Media SA
Subject: Genetics --- Biology --- Biotechnology --- General and Civil Engineering --- Psychiatry --- Medicine (General) --- Physiology --- Neurology --- Science (General)
Added to DOAB on : 2016-02-05 17:24:33
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Aims and Scope: The Research Topic is designed to feature the latest innovative and leading-edge research, reviews and opinions on the study of complex and dynamic processes related to the mammalian immune system and cancer. All papers were meticulously selected to present our readers the multidisciplinary approach to tackle the existing challenges faced in these important fields. From high throughput experimental methodologies to computational and theoretical approaches, the articles are intended to introduce physicists, chemists, computer scientists, biologists and immunologists the idea of systems biology approach to the understanding of mammalian immune system and cancer processes. Attention was given to works that developed more effective approaches to the treatment of proinflammatory disease and cancer. The strong interdisciplinary focus will discuss biological systems at the level from a few molecules to the entire organism. Specific focus domain includes: Innate and adaptive immunity, cancer and cancer stem cell, genomic, proteomic and metabolic analysis, imaging, biophysics of immune and cancer response, computational modeling, non-linear analysis, statistical analysis, translational and disease models Types of articles: Viewpoint, commentaries, research letters, research articles, review and methodologies

Ways to improve tumor uptake and penetration of drugs into solid tumors

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889193509 Year: Pages: 129 DOI: 10.3389/978-2-88919-350-9 Language: English
Publisher: Frontiers Media SA
Subject: Oncology --- Medicine (General) --- Therapeutics --- Science (General)
Added to DOAB on : 2016-03-10 08:14:32
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The main scope of this topic is to give an update on pharmacologic and non-pharmacologic approaches to enhance uptake and penetration of cancer drugs into tumors. Inadequate accumulation of drugs in tumors has emerged over the last decade as one of the main problems underlying therapeutic failure and drug resistance in the treatment of cancer. Insufficient drug uptake and penetration is causally related to the abnormal tumor architecture. Thus, poor vascularization, increased resistance to blood flow and impaired blood supply represent a first obstacle to the delivery of antitumor drugs to tumor tissue. Decreased or even inverted transvascular pressure gradients compromise convective delivery of drugs. Eventually, an abnormal extracellular matrix offers increased frictional resistance to tumor drug penetration. Abnormal tumor architecture also changes the biology of tumor cells, which contributes to drug resistance through several different mechanisms. The variability in vessel location and structure can make many areas of the tumor hypoxic, which causes the tumor cells to become quiescent and thereby resistant to many antitumor drugs. In addition, the abnormally long distance of part of the tumor cell population from blood vessels provides a challenge to delivering cancer drugs to these cells. We have recently proposed additional mechanisms of tumor drug resistance, which are also related to abnormal tumor architecture. First, increased interstitial fluid pressure can by itself induce drug resistance through the induction of resistance-promoting paracrine factors. Second, the interaction of drug molecules with vessel- proximal tumor cell layers may also induce the release of these factors, which can spread throughout the cancer, and induce drug resistance in tumor cells distant from blood vessels. As can be seen, abnormal tumor architecture, inadequate drug accumulation and tumor drug resistance are tightly linked phenomena, suggesting the need to normalize the tumor architecture, including blood vessels, and/or increase the accumulation of cancer drugs in tumors in order to increase therapeutic effects. Indeed, several classes of drugs (that we refer to as promoter drugs) have been described, that promote tumor uptake and penetration of antitumor drugs, including those that are vasoactive, modify the barrier function of tumor vessels, debulk tumor cells, and overcome intercellular and stromal barriers. In addition, also non-pharmacologic approaches have been described that enhance tumor accumulation of effector drugs (e.g. convection-enhanced delivery, hyperthermia, etc.). Some drugs that have already received regulatory approval (e.g. the anti-VEGF antibody bevacizumab) exert antitumor effects at least in part through normalization of the tumor vasculature and enhancement of the accumulation of effector drugs. Other drugs, acting through different mechanisms of action, are now in clinical development (e.g. NGR-TNF in phase II/III studies) and others are about to enter clinical investigation (e.g. JO-1).

Recent advances in Pancreatology

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889193332 Year: Pages: 69 DOI: 10.3389/978-2-88919-333-2 Language: English
Publisher: Frontiers Media SA
Subject: Nutrition and Food Sciences --- Medicine (General) --- Physiology --- Science (General)
Added to DOAB on : 2016-03-10 08:14:32
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Pancreatic diseases include intractable ones including acute and chronic pancreatitis, and pancreatic cancer. In recent years, great advances have been made in the field of pancreatology, including the pathogenesis, diagnostic modalities, and development of novel therapeutic interventions. It has been established that pancreatic stellate cells play a pivotal role in the development of pancreatic fibrosis in chronic pancreatitis as well as in pancreatic cancer known as desmoplastic reaction. Although it might be still controversial, accumulating evidence has shown that interaction between pancreatic stellate cells-cancer cells contribute to the progression of pancreatic cancer through the increased proliferation and migration, and production of cytokines and extracellular matrix components. In addition, pancreatic stellate cells lead to the resistance to chemotherapy and radiation therapy. Pancreatic stellate cells attract the researchers as a novel therapeutic target of pancreatic cancer. Genetic studies have shown that mutations in the trypsin-related genes such as cationic trypsinogen (PRSS1) gene and the serine protease inhibitor, Kazal type 1 (SPINK1) gene are associated with pancreatitis. In general, each of these factors appears to limit trypsin activation or enhance inactivation, and is believed to increase intrapancreatic trypsin activity and predispose to pancreatitis when the gene is mutated. These results have supported a concept that pancreatic protease/anti-protease plays pivotal roles in the pathogenesis of pancreatitis. In addition, genetic studies focusing on phenotypic variances would provide us with important information how genetic variants would affect the phenotypic variances. Autophagy is an intracellular bulk degradation system in which cytoplasmic components are directed to the lysosome/vacuole by a membrane-mediated process. Recent studies have highlighted a role of autophagy in acute pancreatitis. Using a conditional knockout mouse that lacks the autophagy-related (Atg) gene Atg5 in the pancreatic acinar cells, autophagy exerts a detrimental effect in pancreatic acinar cells by activation of trypsinogen to trypsin. A theory in which autophagy accelerates trypsinogen activation by lysosomal hydrolases under acidic conditions, thus triggering acute pancreatitis in its early stage. The epithelial-mesenchymal transition is a developmental process that allows a polarized epithelial cell to undergo multiple biochemical changes that enable it to assume a mesenchymal phenotype. The phenotype associated with epithelial-mesenchymal transition includes enhanced migratory capacity, invasiveness, elevated resistance to apoptosis, and greatly increased production of extracellular matrix components. In addition to its role in development, tissue regeneration, and fibrosis, epithelial-mesenchymal transition is now considered as a critical process in cancer progression. Induction of epithelial-mesenchymal transition in cancer cells results in the acquisition of invasive and metastatic properties. Epithelial-mesenchymal transition could be an important mechanism in the progression of pancreatic cancer and its poor prognosis. Autoimmune pancreatitis is a unique form of pancreatitis in which autoimmune mechanisms are suspected to be involved in the pathogenesis. There is accumulating study to deal with this new disease concept. In addition to these topics, we have selected several topics in pancreatology, focusing on recent studies increasingly deepening our knowledge in both basic and clinical researches.

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2014 (10)