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Sample records for carcinogenesis molecular concepts

  1. Melanoma: Stem cells, sun exposure and hallmarks for carcinogenesis, molecular concepts and future clinical implications

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    Kyrgidis Athanassios

    2010-01-01

    Full Text Available Background :The classification and prognostic assessment of melanoma is currently based on morphologic and histopathologic biomarkers. Availability of an increasing number of molecular biomarkers provides the potential for redefining diagnostic and prognostic categories and utilizing pharmacogenomics for the treatment of patients. The aim of the present review is to provide a basis that will allow the construction-or reconstruction-of future melanoma research. Methods: We critically review the common medical databases (PubMed, EMBASE, Scopus and Cochrane CENTRAL for studies reporting on molecular biomarkers for melanoma. Results are discussed along the hallmarks proposed for malignant transformation by Hanahan and Weinberg. We further discuss the genetic basis of melanoma with regard to the possible stem cell origin of melanoma cells and the role of sunlight in melanoma carcinogenesis. Results: Melanocyte precursors undergo several genome changes -UV-induced or not- which could be either mutations or epigenetic. These changes provide stem cells with abilities to self-invoke growth signals, to suppress anti-growth signals, to avoid apoptosis, to replicate without limit, to invade, proliferate and sustain angiogenesis. Melanocyte stem cells are able to progressively collect these changes in their genome. These new potential functions, drive melanocyte precursors to the epidermis were they proliferate and might cause benign nevi. In the epidermis, they are still capable of acquiring new traits via changes to their genome. With time, such changes could add up to transform a melanocyte precursor to a malignant melanoma stem cell. Conclusions : Melanoma cannot be considered a "black box" for researchers anymore. Current trends in the diagnosis and prognosis of melanoma are to individualize treatment based on molecular biomarkers. Pharmacogenomics constitute a promising field with regard to melanoma patients′ treatment. Finally, development of novel

  2. Diet, lifestyle, and molecular alterations that drive colorectal carcinogenesis

    NARCIS (Netherlands)

    Diergaarde, B.

    2004-01-01

    Environmental factors have been repeatedly implicated in the etiology of colorectal cancer, and much is known about the molecular events involved in colorectal carcinogenesis. The relationships between environmental risk factors and the molecular alterations that drive colorectal carcinogenesis are

  3. Modifier-concept of colorectal carcinogenesis: Lipidomics as a technical tool in pathway analysis

    Institute of Scientific and Technical Information of China (English)

    Nikolaus; Gassler; Christina; Klaus; Elke; Kaemmerer; Andrea; Reinartz

    2010-01-01

    In the modifier concept of intestinal carcinogenesis, lipids have been established as important variables and one focus is given to long-chain fatty acids. Increased consumption of long-chain fatty acids is in discussion to modify the development of colorectal carcinoma in humans. Saturated long-chain fatty acids, in particular, are assumed to promote carcinogenesis, whereas poly-unsaturated forms are likely to act in the opposite way. At present, the molecular mechanisms behind these effects are not well u...

  4. Molecular aspects of carcinogenesis in pancreatic cancer

    Institute of Scientific and Technical Information of China (English)

    Alexandros Koliopanos; Constantinos Avgerinos; Constantina Paraskeva; Zisis Touloumis; Dionisisa Kelgiorgi; Christos Dervenis

    2008-01-01

    BACKGROUND: Pancreatic cancer (PCa) is one of the most aggressive human solid tumors, with rapid growth and metastatic spread as well as resistance to chemotherapeutic drugs, leading rapidly to virtually incurable disease. Over the last 20 years, however, signiifcant advances have been made in our understanding of the molecular biology of PCa, with a focus on the cytogenetic abnormalities in PCa cell growth and differentiation. DATA SOURCES: A MEDLINE search and manual cross-referencing were utilized to identify published data for PCa molecular biology studies between 1986 and 2008, with emphasis on genetic alterations and developmental oncology. RESULTS: Activation of oncogenes, deregulation of tumor suppressor and genome maintenance genes, upregulation of growth factors/growth factor receptor signaling cascade systems, and alterations in cytokine expression, have been reported to play important roles in the process of pancreatic carcinogenesis. Alterations in the K-ras proto-oncogene and the p16INK4a, p53, FHIT, and DPC4 tumor suppressor genes occur in a high percentage of tumors. Furthermore, a variety of growth factors are expressed at increased levels. In addition, PCa often exhibits alterations in growth inhibitory pathways and evades apoptosis through p53 mutations and aberrant expression of apoptosis-regulating genes, such as members of the Bcl family. Additional pathways in the development of an aggressive phenotype, local inifltration and metastasis are still under ongoing genetic research. The present paper reviews recent studies on the pathogenesis of PCa, and includes a brief reference to alterations reported for other types of pancreatic tumor. CONCLUSIONS: Advances in molecular genetics and biology have improved our perception of the pathogenesis of PCa. However, further studies are needed to better understand the fundamental changes that occur in PCa, thus leading to better diagnostic and therapeutic management.

  5. Molecular oncology focus - Is carcinogenesis a 'mitochondriopathy'?

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    Ścińska Anna

    2010-04-01

    Full Text Available Abstract Mitochondria are sub-cellular organelles that produce adenosine triphosphate (ATP through oxidative phosphorylation (OXPHOS. As suggested over 70 years ago by Otto Warburg and recently confirmed with molecular techniques, alterations in respiratory activity and in mitochondrial DNA (mtDNA appear to be common features of malignant cells. Somatic mtDNA mutations have been reported in many types of cancer cells, and some reports document the prevalence of inherited mitochondrial DNA polymorphisms in cancer patients. Nevertheless, a careful reanalysis of methodological criteria and methodology applied in those reports has shown that numerous papers can't be used as relevant sources of data for systematic review, meta-analysis, or finally for establishment of clinically applicable markers. In this review technical and conceptual errors commonly occurring in the literature are summarized. In the first place we discuss, why many of the published papers cannot be used as a valid and clinically useful sources of evidence in the biomedical and healthcare contexts. The reasons for introduction of noise in data and in consequence - bias for the interpretation of the role of mitochondrial DNA in the complex process of tumorigenesis are listed. In the second part of the text practical aspects of mtDNA research and requirements necessary to fulfill in order to use mtDNA analysis in clinics are shown. Stringent methodological criteria of a case-controlled experiment in molecular medicine are indicated. In the third part we suggest, what lessons can be learned for the future and propose guidelines for mtDNA analysis in oncology. Finally we conclude that, although several conceptual and methodological difficulties hinder the research on mitochondrial patho-physiology in cancer cells, this area of molecular medicine should be considered of high importance for future clinical practice.

  6. A review of molecular events of cadmium-induced carcinogenesis.

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    Luevano, Joe; Damodaran, Chendil

    2014-01-01

    Cadmium (Cd) is a toxic, heavy industrial metal that poses serious environmental health hazards to both humans and wildlife. Recently, Cd and Cd-containing compounds have been classified as known human carcinogens, and epidemiological data show causal associations with prostate, breast, and lung cancer. The molecular mechanisms involved in Cd-induced carcinogenesis are poorly understood and are only now beginning to be elucidated. The effects of chronic exposure to Cd have recently attracted great interest due to the development of malignancies in Cd-induced tumorigenesis in animals models. Briefly, various in vitro studies demonstrate that Cd can act as a mitogen, can stimulate cell proliferation and inhibit apoptosis and DNA repair, and can induce carcinogenesis in several mammalian tissues and organs. Thus, the various mechanisms involved in chronic Cd exposure and malignant transformations warrant further investigation. In this review, we focus on recent evidence of various leading general and tissue-specific molecular mechanisms that follow chronic exposure to Cd in prostate-, breast-, and lung-transformed malignancies. In addition, in this review, we consider less defined mechanisms such as epigenetic modification and autophagy, which are thought to play a role in the development of Cd-induced malignant transformation.

  7. The molecular mechanisms of hazardous metals for carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    ChenJK; LeiYX

    2002-01-01

    The available experimental and epidemiological data have shown that nickel (Ni) and cadmium (Dd) and their compounds are carcinogenic to experimental animals and human.These two metals have been classified as human carcinogens bythe International Agency for Research on Cancer (IARC).However,Their underlying molecular mechanisms remain unknown.The objective of this research was to investigate the molecular mechanisms responsible for Ni and Cd carcinogenesis through epidemiological study in human exposure,transformation expreiments in human epithelial cells (16HBE) and BALB/c-3T3 cell lines in vitro,DNA damage detections (comet,DNA-protein crosslinks) as well as telomerase activity and apoptosis assay,and analysis of oncogens,tumor suppressor genes and their mutation (including genomic instability,k-ras,p15,p16,p53,FHIT) in transformed cell lines or tumor cells/tissue.Furthermore,we also detected and analyses the methylation,related novel genes and encoded protein in Cd transformed cells.The results and conclusion are as follows:(1)There is significant relationship between some hazardous metals and lung cancer (OR=8.76),especially for nickel(OR=11.25).(2)Ni and Cd and their compounds could induce malignant transformation in mammalian cell lines and human epithelial cells,and induce tumorigenesis in nude mice.(3)There is obvious DNA damage during cell transformation and tumorigenesis induced by Ni.(4) Significant genomic instability has been shown during cell transformation and tumorigenesis induced by Ni.(5)Detection of k-ras,p15,p16 genes in point mutation have demonstrated no changes during cell transformation and tumorigenesis induced by hazardous medals,suggesting that gene mutation is not the main way to metal carcinogenesis.(6)There are some aberrant DNA methylation in Cdtransformed cell lines.(7)We found two novel Cd-responsive proto-oncogenes and their encoded proteins in Cd-transformed cell lines.

  8. BRAFV600E: implications for carcinogenesis and molecular therapy.

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    Cantwell-Dorris, Emma R

    2012-02-01

    The mitogen-activated protein kinase (MAPK)\\/extracellular signal-regulated kinase (ERK) pathway is frequently mutated in human cancer. This pathway consists of a small GTP protein of the RAS family that is activated in response to extracellular signaling to recruit a member of the RAF kinase family to the cell membrane. Active RAF signals through MAP\\/ERK kinase to activate ERK and its downstream effectors to regulate a wide range of biological activities including cell differentiation, proliferation, senescence, and survival. Mutations in the v-raf murine sarcoma viral oncogenes homolog B1 (BRAF) isoform of the RAF kinase or KRAS isoform of the RAS protein are found as activating mutations in approximately 30% of all human cancers. The BRAF pathway has become a target of interest for molecular therapy, with promising results emerging from clinical trials. Here, the role of the most common BRAF mutation BRAF(V600E) in human carcinogenesis is investigated through a review of the literature, with specific focus on its role in melanoma, colorectal, and thyroid cancers and its potential as a therapeutic target.

  9. Molecular and cellular pathways associated with chromosome 1p deletions during colon carcinogenesis

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    Payne CM

    2011-05-01

    Full Text Available Claire M Payne, Cheray Crowley-Skillicorn, Carol Bernstein, Hana Holubec, Harris BernsteinDepartment of Cell Biology and Anatomy, College of Medicine, University of Arizona Tucson, AZ, USAAbstract: Chromosomal instability is a major pathway of sporadic colon carcinogenesis. Chromosome arm 1p appears to be one of the “hot spots” in the non-neoplastic mucosa that, when deleted, is associated with the initiation of carcinogenesis. Chromosome arm 1p contains genes associated with DNA repair, spindle checkpoint function, apoptosis, multiple microRNAs, the Wnt signaling pathway, tumor suppression, antioxidant activities, and defense against environmental toxins. Loss of 1p is dangerous since it would likely contribute to genomic instability leading to tumorigenesis. The 1p deletion-associated colon carcinogenesis pathways are reviewed at the molecular and cellular levels. Sporadic colon cancer is strongly linked to a high-fat/low-vegetable/low-micronutrient, Western-style diet. We also consider how selected dietary-related compounds (eg, excess hydrophobic bile acids, and low levels of folic acid, niacin, plant-derived antioxidants, and other modulatory compounds might affect processes leading to chromosomal deletions, and to the molecular and cellular pathways specifically altered by chromosome 1p loss.Keywords: chromosome 1p, colon carcinogenesis, molecular pathways, cellular pathways

  10. Recent advances in molecular biology of gastric carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    萧树东; 冉志华

    2003-01-01

    Gastric cancer is a major health care problem and the second most common fatal cancer worldwide. In the last decade, better insight has been gained into the molecular basis underlying the neoplasitc transformation of stomach. The dramatic variation in the incidence of gastric cancer in different geographical areas and from one generation to the next have led to the hypothesis that the incidence of gastric cancer is determined largely by environmental rather than genetic factors.

  11. Gastric Carcinogenesis and Underlying Molecular Mechanisms: Helicobacter pylori and Novel Targeted Therapy

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    Toshihiro Nishizawa

    2015-01-01

    Full Text Available The oxygen-derived free radicals that are released from activated neutrophils are one of the cytotoxic factors of Helicobacter pylori-induced gastric mucosal injury. Increased cytidine deaminase activity in H. pylori-infected gastric tissues promotes the accumulation of various mutations and might promote gastric carcinogenesis. Cytotoxin-associated gene A (CagA is delivered into gastric epithelial cells via bacterial type IV secretion system, and it causes inflammation and activation of oncogenic pathways. H. pylori infection induces epigenetic transformations, such as aberrant promoter methylation in tumor-suppressor genes. Aberrant expression of microRNAs is also reportedly linked to gastric tumorogenesis. Moreover, recent advances in molecular targeting therapies provided a new interesting weapon to treat advanced gastric cancer through anti-human epidermal growth factor receptor 2 (HER-2 therapies. This updated review article highlights possible mechanisms of gastric carcinogenesis including H. pylori-associated factors.

  12. Molecular Portrait of the Normal Human Breast Tissue and Its Influence on Breast Carcinogenesis.

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    Margan, Madalin Marius; Jitariu, Andreea Adriana; Cimpean, Anca Maria; Nica, Cristian; Raica, Marius

    2016-06-01

    Normal human breast tissue consists of epithelial and nonepithelial cells with different molecular profiles and differentiation grades. This molecular heterogeneity is known to yield abnormal clones that may contribute to the development of breast carcinomas. Stem cells that are found in developing and mature breast tissue are either positive or negative for cytokeratin 19 depending on their subtype. These cells are able to generate carcinogenesis along with mature cells. However, scientific data remains controversial regarding the monoclonal or polyclonal origin of breast carcinomas. The majority of breast carcinomas originate from epithelial cells that normally express BRCA1. The consecutive loss of the BRCA1 gene leads to various abnormalities in epithelial cells. Normal breast epithelial cells also express hypoxia inducible factor (HIF) 1α and HIF-2α that are associated with a high metastatic rate and a poor prognosis for malignant lesions. The nuclear expression of estrogen receptor (ER) and progesterone receptor (PR) in normal human breast tissue is maintained in malignant tissue as well. Several controversies regarding the ability of ER and PR status to predict breast cancer outcome remain. Both ER and PR act as modulators of cell activity in normal human breast tissue. Ki-67 positivity is strongly correlated with tumor grade although its specific role in applied therapy requires further studies. Human epidermal growth factor receptor 2 (HER2) oncoprotein is less expressed in normal human breast specimens but is highly expressed in certain malignant lesions of the breast. Unlike HER2, epidermal growth factor receptor expression is similar in both normal and malignant tissues. Molecular heterogeneity is not only found in breast carcinomas but also in normal breast tissue. Therefore, the molecular mapping of normal human breast tissue might represent a key research area to fully elucidate the mechanisms of breast carcinogenesis.

  13. Report of National Cancer Institute symposium: comparison of mechanisms of carcinogenesis by radiation and chemical agents. I. Common molecular mechanisms

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    Borg, D.C.

    1984-01-01

    Some aspects of molecular mechanisms common to radiation and chemical carcinogenesis are discussed, particularly the DNA damage done by these agents. Emphasis is placed on epidemiological considerations and on dose-response models used in risk assessment to extrapolate from experimental data obtained at high doses to the effects from long-term, low-level exposures. 3 references, 6 figures. (ACR)

  14. The role of B-vitamins - gene interactions in colorectal carcinogenesis: A molecular epidemiological approach

    NARCIS (Netherlands)

    Donk, van den M.

    2005-01-01

    Folate deficiency can affect DNA methylation and DNA synthesis. Both factors may be operative in colorectal carcinogenesis. Many enzymes, like methylenetetrahydrofolate reductase (MTHFR), thymidylate synthase (TS), methionine synthase (MTR), and serine hydroxymethyltransferase (SHMT), are needed for

  15. The molecular concept of law

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    Hendrik Gommer

    2011-04-01

    Full Text Available In his famous work The Concept of Law Hart asked himself the question 'what is law?' Hart makes a very strict distinction between rules and morals: morals are rooted in biology, rules source back to society. Hart's sociological truisms have proven to be untrue, because modern evolutionary biology is not about the survival of the individual (or even of a species but about the spreading of genes. This knowledge changes the fundamentals of Hart's theory and therefore his theory as a whole. In addition, my theory captures vital insights of Dworkin, legal realism, Posner and CLS, while at the same time forming a significant improvement upon them.In essence, the biological theory of law presented in this article is based on fractal patterns. Macroscale patterns recur in microscale patterns. The spreading of genes depends on important characteristics of genes: they are stable, they replicate, they need nutrients to replicate and they can cooperate. Superficially, genes, cells, organisms and groups may seem to act purposefully, but it is merely a pattern, with genes as generators, that brings structure to chaos. Human desires are in fact the needs of their genes. Thanks to language, morals can be put in words and become rules. To keep everyone working together, we need an ingenious device - like the law - to maintain that complex situations can continue to be judged on the basis of the simple principle of stability and reciprocity. To a degree, therefore, law itself can be derived from unconscious emotions and morals.

  16. Molecular Phylogenetics: Concepts for a Newcomer.

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    Ajawatanawong, Pravech

    2016-10-26

    Molecular phylogenetics is the study of evolutionary relationships among organisms using molecular sequence data. The aim of this review is to introduce the important terminology and general concepts of tree reconstruction to biologists who lack a strong background in the field of molecular evolution. Some modern phylogenetic programs are easy to use because of their user-friendly interfaces, but understanding the phylogenetic algorithms and substitution models, which are based on advanced statistics, is still important for the analysis and interpretation without a guide. Briefly, there are five general steps in carrying out a phylogenetic analysis: (1) sequence data preparation, (2) sequence alignment, (3) choosing a phylogenetic reconstruction method, (4) identification of the best tree, and (5) evaluating the tree. Concepts in this review enable biologists to grasp the basic ideas behind phylogenetic analysis and also help provide a sound basis for discussions with expert phylogeneticists.

  17. Non-steroidal anti-inflammatory drugs and molecular carcinogenesis of colorectal carcinomas

    NARCIS (Netherlands)

    Huls, G; Koornstra, JJ; Kleibeuker, JH

    2003-01-01

    Context Colorectal cancer is the second most common cause of cancer-related mortality in the west. The high incidence and mortality make effective prevention an important public-health and economic issue. Non-steroidal anti-inflammatory drugs (NSAIDs) can inhibit colorectal-carcinogenesis and are am

  18. Diet, lifestyle, heritable factors and colorectal carcinogenesis: associations with histopathological and molecular endpoints

    NARCIS (Netherlands)

    Wark, P.A.

    2007-01-01

    Background: Diet, lifestyle and heritable factors have been related to colorectal cancer risk; to date, their relevance to the overall scope of colorectal carcinogenesis, has not been clearly established.Aim and Methods: To evaluate whether distinguishing colorectal tissue by its histopathological a

  19. Histone acetyltransferases and deacetylases: molecular and clinical implications to gastrointestinal carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    Wei-Jian Sun; Xiang Zhou; Ji-Hang Zheng; Ming-Dong Lu; Jian-Yun Nie; Xiang-Jiao Yang; Zhi-Qiang Zheng

    2012-01-01

    Histone acetyltransferases and deacetylases are two groups of enzymes whose opposing activities govern the dynamic levels of reversible acetylation on specific lysine residues of histones and many other proteins.Gastrointestinal (GI) carcinogenesis is a major cause of morbidity and mortality worldwide.In addition to genetic and environmental factors,the role of epigenetic abnormalities such as aberrant histone acetylation has been recognized to be pivotal in regulating benign tumorigenesis and eventual malignant transformation.Here we provide an overview of histone acetylation,list the major groups of histone acetyltransferases and deacetylases,and cover in relatively more details the recent studies that suggest the links of these enzymes to GI carcinogenesis.As potential novel therapeutics for GI and other cancers,histone deacetylase inhibitors are also discussed.

  20. Molecular analysis of tumor-promoting CD8+ T cells in two-stage cutaneous chemical carcinogenesis.

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    Kwong, Bernice Y; Roberts, Scott J; Silberzahn, Tobias; Filler, Renata B; Neustadter, Jason H; Galan, Anjela; Reddy, Swapna; Lin, William M; Ellis, Peter D; Langford, Cordelia F; Hayday, Adrian C; Girardi, Michael

    2010-06-01

    T-pro are tumor-infiltrating TCRalphabeta(+)CD8(+) cells of reduced cytotoxic potential that promote experimental two-stage chemical cutaneous carcinogenesis. Toward understanding their mechanism of action, this study uses whole-genome expression analysis to compare T-pro with systemic CD8(+) T cells from multiple groups of tumor-bearing mice. T-pro show an overt T helper 17-like profile (high retinoic acid-related orphan receptor-(ROR)gammat, IL-17A, IL-17F; low T-bet and eomesodermin), regulatory potential (high FoxP3, IL-10, Tim-3), and transcripts encoding epithelial growth factors (amphiregulin, Gro-1, Gro-2). Tricolor flow cytometry subsequently confirmed the presence of TCRbeta(+) CD8(+) IL-17(+) T cells among tumor-infiltrating lymphocytes (TILs). Moreover, a time-course analysis of independent TIL isolates from papillomas versus carcinomas exposed a clear association of the "T-pro phenotype" with malignant progression. This molecular characterization of T-pro builds a foundation for elucidating the contributions of inflammation to cutaneous carcinogenesis, and may provide useful biomarkers for cancer immunotherapy in which the widely advocated use of tumor-specific CD8(+) cytolytic T cells should perhaps accommodate the cells' potential corruption toward the T-pro phenotype. The data are also likely germane to psoriasis, in which the epidermis may be infiltrated by CD8(+) IL-17-producing T cells.

  1. Molecular characterization of cancer reveals interactions between ionizing radiation and chemicals on rat mammary carcinogenesis.

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    Imaoka, Tatsuhiko; Nishimura, Mayumi; Doi, Kazutaka; Tani, Shusuke; Ishikawa, Ken-ichi; Yamashita, Satoshi; Ushijima, Toshikazu; Imai, Takashi; Shimada, Yoshiya

    2014-04-01

    Although various mechanisms have been inferred for combinatorial actions of multiple carcinogens, these mechanisms have not been well demonstrated in experimental carcinogenesis models. We evaluated mammary carcinogenesis initiated by combined exposure to various doses of radiation and chemical carcinogens. Female rats at 7 weeks of age were γ-irradiated (0.2-2 Gy) and/or exposed to 1-methyl-1-nitrosourea (MNU) (20 or 40 mg/kg, single intraperitoneal injection) or 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) (40 mg/kg/day by gavage for 10 days) and were observed until 50 weeks of age. The incidence of mammary carcinoma increased steadily as a function of radiation dose in the absence of chemicals; mathematical analysis supported an additive increase when radiation was combined with a chemical carcinogen, irrespective of the chemical species and its dose. Hras mutations were characteristic of carcinomas that developed after chemical carcinogen treatments and were overrepresented in carcinomas induced by the combination of radiation and MNU (but not PhIP), indicating an interaction of radiation and MNU at the level of initiation. The expression profiles of seven classifier genes, previously shown to distinguish two classes of rat mammary carcinomas, categorized almost all examined carcinomas that developed after individual or combined treatments with radiation (1 Gy) and chemicals as belonging to a single class; more comprehensive screening using microarrays and a separate test sample set failed to identify differences in gene expression profiles among these carcinomas. These results suggest that a complex, multilevel interaction underlies the combinatorial action of radiation and chemical carcinogens in the experimental model.

  2. Molecular pathways to therapeutics: Paradigms and challenges in oncology meeting report: Carcinogenesis 2015

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    Ujjwala M Warawdekar

    2015-01-01

    Full Text Available The search for the most effective therapy with minimum side effects has always been the goal of oncologists and efforts to develop such therapies through understanding disease mechanisms has been the focus of many basic scientists in cancer research, leading to a common interest of convergence. The 5 th International Conference organized by the Carcinogenesis Foundation, USA and Advanced Centre for Treatment, Research and Education in Cancer (ACTREC, Tata Memorial Centre, India, was held between February 11 th and 13 th 2015, at ACTREC. During these proceedings, the scientific community engaged in oncology research discussed novel ideas emerging from the laboratory and their translation into improved clinical outcomes. However, the lack of major success in the genesis of novel cancer therapeutics that is safe and provides long-term relief to patients is a challenge that needs to be overcome. The focus of this meeting was to highlight these challenges and to encourage collaborations between scientists and clinicians and clearly a message through exemplary scientific contribution was conveyed to all the dedicated scientists and clinician that even if two decades of tireless work on a single idea does not generate a reliable and safe therapy, the combat to rein cancer must not cease. In this report we have communicated some of the outstanding work done in the areas of cancer therapeutics, biomarkers and prevention and described the salient observations associated with cancer stem cells in disease progression and some of the pathways implicated in tumor progression.

  3. Monitoring pancreatic carcinogenesis by the molecular imaging of cathepsin E in vivo using confocal laser endomicroscopy.

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    Hui Li

    Full Text Available The monitoring of pancreatic ductal adenocarcinoma (PDAC in high-risk populations is essential. Cathepsin E (CTSE is specifically and highly expressed in PDAC and pancreatic intraepithelial neoplasias (PanINs, and its expression gradually increases along with disease progression. In this study, we first established an in situ 7,12-dimethyl-1,2-benzanthracene (DMBA-induced rat model for PanINs and PDAC and then confirmed that tumorigenesis properties in this model were consistent with those of human PDAC in that CTSE expression gradually increased with tumor development using histology and immunohistochemistry. Then, using in vivo imaging of heterotopically implanted tumors generated from CTSE- overexpressing cells (PANC-1-CTSE in nude mice and in vitro imaging of PanINs and PDAC in DMBA-induced rats, the specificity of the synthesized CTSE-activatable probe was verified. Quantitative determination identified that the fluorescence signal ratio of pancreatic tumor to normal pancreas gradually increased in association with progressive pathological grades, with the exception of no significant difference between PanIN-II and PanIN-III grades. Finally, we monitored pancreatic carcinogenesis in vivo using confocal laser endomicroscopy (CLE in combination with the CTSE-activatable probe. A prospective double-blind control study was performed to evaluate the accuracy of this method in diagnosing PDAC and PanINs of all grades (>82.7%. This allowed us to establish effective diagnostic criteria for CLE in PDAC and PanINs to facilitate the monitoring of PDAC in high-risk populations.

  4. The molecular concept of atheromatous plaques.

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    Thent, Zar Chi; Chakraborty, Chiranjib; Mahakkanukrauh, Pasuk; Kosai, Nik; Rajan, Reynu; Das, Srijit

    2016-05-02

    Recently, there are scientific attempts to devise new drugs in the biotechnology industry in order to treat various diseases including atherosclerosis. Atherosclerosis is considered to be a leading cause of death throughout the world. Atherosclerosis involves oxidative damage to the cells with production of reactive oxygen species (ROS). Development of atheromatous plaques in the arterial wall is a common feature. Specific inflammatory markers pertaining to the arterial wall in atherosclerosis may be useful for both diagnosis and treatment. These include macrophage inhibiting factor (MIF), leucocytes and P-selectin. Modern therapeutic paradigms involving endothelial progenitor cells therapy, angiotensin II type-2 (AT2R) and ATP-activated purinergic receptor therapy are notable to mention. Future drugs may be designed aiming three signalling mechanisms of AT2R which are (a) activation of protein phosphatases resulting in protein dephosphorylation (b) activation of bradykinin/nitric oxide/cyclic guanosine 3',5'-monophosphate pathway by vasodilation and (c) stimulation of phospholipase A(2) and release of arachidonic acid. Drugs may also be designed to act on ATP-activated purinergic receptor channel type P2X7 molecules which acts on cardiovascular system. In the present review, we discuss the molecular concept of the inflammatory process occurring inside the arterial wall. Better understanding of the vascular inflammatory processes and the cells involved in the formation of plaques, may prove to be beneficial for future diagnosis, clinical treatment and planning innovative novel anti-atherosclerotic drugs.

  5. Célula tronco tumoral: novo conceito em carcinogênese colorretal Câncer stem cells: a new concept in colorectal carcinogenesis

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    Mauro de Souza Leite Pinho

    2009-03-01

    Full Text Available Apesar dos grandes avanços obtidos pelos estudos utilizando técnicas de biologia molecular diversas controvérsias persistem a respeito do mecanismo de carcinogênese colorretal. Ao longo do último ano, entretanto, observamos na literatura o surgimento de um novo conceito referente à existência de um conjunto de células situadas nas bases das criptas intestinais, as quais apresentam características bastante distintas do restante das células epiteliais. Estas células, denominadas como células tronco intestinais, apresentam-se de forma indiferenciada e com um ciclo de vida com duração superior a um ano. Desta forma, justifica-se assim nestas células a possibilidade da ocorrência de um acúmulo de mutações, etapa considerada essencial para o desenvolvimento do processo neoplásico, e que seria improvável de ocorrer em um colonócito normal, cujo ciclo de vida dura em média cinco dias. Outra importante evidência da participação destas células tronco no mecanismo de carcinogênese foi demonstrada por estudos capazes de reproduzir a formação de tecidos neoplásicos com a mesma característica do tumor original, a partir do implante de um reduzido número destas células em modelos experimentais, o que não se obtém através do implante de um grande número de células tumorais normais. Sabendo-se que a presença de uma mutação do gene APC é uma etapa precoce no processo de carcinogênese colorretal, acredita-se que esta exerça este papel contribuindo para a ocorrência de uma superpopulação de células tronco intestinais, levando a um desequilíbrio proliferativo na mucosa intestinal.Despite the great number of studies using molecular biology tools several questions remain about the mechanisms of colorectal carcinogenesis. A recent concept has emerged from the literature regarding the existence of a specific group of indiferentiated cells situated at the bottom of intestinal crypts with a long life cycle that may last

  6. [New concepts in molecular biology applied to traslational research].

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    Mengual, Lourdes

    2013-06-01

    This chapter intends to introduce the new concepts that have been established in molecular biology over the last years and are being applied in translational research. The chapter is divided in four big blocks, which treat the molecular biology concepts and techniques in relation to DNA, RNA, proteins and metabolites, respectively. Moreover, we give examples of translational application of these new methodologies described.

  7. The molecular basis for carcinogenesis in metaplastic columnar-lined esophagus.

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    Souza, R F; Meltzer, S J

    1997-09-01

    A wide variety of biologic events and mechanisms appear to have roles in the development and progression of Barrett's esophagus-associated neoplastic lesions. Figure 5 is a schematic depiction of these events. This is known as an infernogram (named after Dante's Inferno) (S. Kern, unpublished presentations, 1996). Events at the bottom rings of the inferno are high-frequency mutations; nearer to the top of the inferno are the less common events. The next several years promise many further discoveries of not only high-frequency and low-frequency events, but also their application. Some of the molecular alterations already studied show promise as markers for early cancer detection or prognostication. Eventually, applications of these discoveries should yield new and more effective means of preventing and treating the deadly complications of this troublesome premalignant condition.

  8. [Correlation between histological and molecular mechanisms of carcinogenesis in stomach cancer].

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    Rüschoff, J; Mehringer, S; Beyser, K; Dietmaier, W; Langner, C; Bocker, T; Kullmann, F

    1999-01-01

    Since gastric cancer is an exceptional heterogeneous tumor conflicting results have been obtained about the relationship between genotype and phenotype. From the molecular point of view gastric carcinoma diffuse type forms a distinct entity which is microsatellite stable, has almost no p53 mutations and exhibits in at least half of the cases mutations in the E-cadherin gene. In contrast, all other gastric carcinomas comprise a heterogeneous group of which about one third exhibits microsatellite instability (MSI) but no p53 protein stabilization or gene mutations. These tumors are either of pure intestinal (glandular) type or show large solid (medullary) tumor cell clusters. Thereby, in sporadic gastric cancer MSI is caused by loss of hMLH1 expression due to hypermethylation of the promotor region rather than by mutation of the gene itself. Tumors that are microsatellite stable (MSS) and show p53 alterations are either intestinal (about 70%) or a mixed-type encompassing at least 5% glandular and poorly differentiated diffuse components (about 30%). Whereas pure diffuse type gastric cancer is unlikely to develop from intestinal type carcinoma, this may, however, be the case in some advanced mixed-type gastric cancers.

  9. Defining Molecular Sensors to Assess Long-Term Effects of Pesticides on Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Fanny L'Héritier

    2014-09-01

    Full Text Available The abundance of dioxins and dioxin-like pollutants has massively increased in the environment due to human activity. These chemicals are particularly persistent and accumulate in the food chain, which raises major concerns regarding long-term exposure to human health. Most dioxin-like pollutants activate the aryl hydrocarbon receptor (AhR transcription factor, which regulates xenobiotic metabolism enzymes that belong to the cytochrome P450 1A family (that includes CYP1A1 and CYP1B1. Importantly, a crosstalk exists between estrogen receptor α (ERα and AhR. More specifically, ERα represses the expression of the CYP1A1 gene, which encodes an enzyme that converts 17β-estradiol into 2-hydroxyestradiol. However, (ERα does not repress the CYP1B1 gene, which encodes an enzyme that converts 17β-estradiol into 4-hydroxyestradiol, one of the most genotoxic estrogen metabolites. In this review, we discuss how chronic exposure to xenobiotic chemicals, such as pesticides, might affect the expression of genes regulated by the AhR–ERα crosstalk. Here, we focus on recent advances in the understanding of molecular mechanisms that mediate this crosstalk repression, and particularly on how ERα represses the AhR target gene CYP1A1, and could subsequently promote breast cancer. Finally, we propose that genes implicated in this crosstalk could constitute important biomarkers to assess long-term effects of pesticides on human health.

  10. Molecular evolution of colorectal cancer: from multistep carcinogenesis to the big bang.

    Science.gov (United States)

    Amaro, Adriana; Chiara, Silvana; Pfeffer, Ulrich

    2016-03-01

    Colorectal cancer is characterized by exquisite genomic instability either in the form of microsatellite instability or chromosomal instability. Microsatellite instability is the result of mutation of mismatch repair genes or their silencing through promoter methylation as a consequence of the CpG island methylator phenotype. The molecular causes of chromosomal instability are less well characterized. Genomic instability and field cancerization lead to a high degree of intratumoral heterogeneity and determine the formation of cancer stem cells and epithelial-mesenchymal transition mediated by the TGF-β and APC pathways. Recent analyses using integrated genomics reveal different phases of colorectal cancer evolution. An initial phase of genomic instability that yields many clones with different mutations (big bang) is followed by an important, previously not detected phase of cancer evolution that consists in the stabilization of several clones and a relatively flat outgrowth. The big bang model can best explain the coexistence of several stable clones and is compatible with the fact that the analysis of the bulk of the primary tumor yields prognostic information.

  11. Theoretical Concepts in Molecular Photodissociation Dynamics

    DEFF Research Database (Denmark)

    Henriksen, Niels Engholm

    1995-01-01

    This chapter contains sections titled: Introduction Quantum Dynamics of Molecular Photofragmentation The Total Reaction Probability Final Product Distributions Time-Independent Approach, Stationary Scattering States Gaussian Wave Packet Dynamics Wigner Phase Space Representation The Diatomic Mole...

  12. The Molecular Biology Capstone Assessment: A Concept Assessment for Upper-Division Molecular Biology Students

    Science.gov (United States)

    Couch, Brian A.; Wood, William B.; Knight, Jennifer K.

    2015-01-01

    Measuring students' conceptual understandings has become increasingly important to biology faculty members involved in evaluating and improving departmental programs. We developed the Molecular Biology Capstone Assessment (MBCA) to gauge comprehension of fundamental concepts in molecular and cell biology and the ability to apply these concepts in…

  13. Chemical carcinogenesis

    Directory of Open Access Journals (Sweden)

    Paula A. Oliveira

    2007-12-01

    Full Text Available The use of chemical compounds benefits society in a number of ways. Pesticides, for instance, enable foodstuffs to be produced in sufficient quantities to satisfy the needs of millions of people, a condition that has led to an increase in levels of life expectancy. Yet, at times, these benefits are offset by certain disadvantages, notably the toxic side effects of the chemical compounds used. Exposure to these compounds can have varying effects, ranging from instant death to a gradual process of chemical carcinogenesis. There are three stages involved in chemical carcinogenesis. These are defined as initiation, promotion and progression. Each of these stages is characterised by morphological and biochemical modifications and result from genetic and/or epigenetic alterations. These genetic modifications include: mutations in genes that control cell proliferation, cell death and DNA repair - i.e. mutations in proto-oncogenes and tumour suppressing genes. The epigenetic factors, also considered as being non-genetic in character, can also contribute to carcinogenesis via epigenetic mechanisms which silence gene expression. The control of responses to carcinogenesis through the application of several chemical, biochemical and biological techniques facilitates the identification of those basic mechanisms involved in neoplasic development. Experimental assays with laboratory animals, epidemiological studies and quick tests enable the identification of carcinogenic compounds, the dissection of many aspects of carcinogenesis, and the establishment of effective strategies to prevent the cancer which results from exposure to chemicals.A sociedade obtém numerosos benefícios da utilização de compostos químicos. A aplicação dos pesticidas, por exemplo, permitiu obter alimento em quantidade suficiente para satisfazer as necessidades alimentares de milhões de pessoas, condição relacionada com o aumento da esperança de vida. Os benefícios estão, por

  14. Gastric carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    Ismail Gomceli; Baris Demiriz; Mesut Tez

    2012-01-01

    Gastric cancer is the second most common cancer worldwide and the second most common cause of cancer-related deaths.Despite complete resection of gastric cancer and lymph node dissection,as well as improvements in chemotherapy and radiotherapy,there are still 700 000 gastric cancer-related deaths per year worldwide and more than 80% of patients with advanced gastric cancer die of the disease or recurrent disease within 1 year after diagnosis.None of the treatment modalities we have been applying today can influence the overall survival rates:at present,the overall 5-year relative survival rate for gastric cancer is about 28%.Cellular metaplasia due to chronic inflammation,injury and repair are the most documented processes for neoplasia.It appears that chronic inflammation stimulates tumor development and plays a critical role in initiating,sustaining and advancing tumor growth.It is also evident that not all inflammation is tumorigenic.Additional mutations can be acquired,and this leads to the cancer cell gaining a further growth advantage and acquiring a more malignant phenotype.Intestinalization of gastric units,which is called "intestinal metaplasia";phenotypic antralization of fundic units,which is called "spasmolytic polypeptide-expressing metaplasia"; and the development directly from the stem/progenitor cell zone are three pathways that have been described for gastric carcinogenesis.Also,an important factor for the development of gastrointestinal cancers is peritumoral stroma.However,the initiating cellular event in gastric metaplasia is still controversial.Understanding gastric carcinogenesis and its precursor lesions has been under intense investigation,and our paper attempts to high-light recent progress in this field of cancer research.

  15. Cadmium carcinogenesis – some key points

    OpenAIRE

    2011-01-01

    The article presents briefly the main mechanisms of cadmium carcinogenesis and the most important sites of cancer (lung, breast, prostate, testes, kidney) induced by cadmium. In spite of some evidence showing carcinogenic potential of cadmium, further research is still required to elucidate the relative contributions of various molecular mechanisms involved in cadmium carcinogenesis

  16. Cadmium carcinogenesis – some key points

    Directory of Open Access Journals (Sweden)

    Loreta Strumylaite

    2011-09-01

    Full Text Available The article presents briefly the main mechanisms of cadmium carcinogenesis and the most important sites of cancer (lung, breast, prostate, testes, kidney induced by cadmium. In spite of some evidence showing carcinogenic potential of cadmium, further research is still required to elucidate the relative contributions of various molecular mechanisms involved in cadmium carcinogenesis

  17. Chemopreventive efficacy of hesperidin against chemically induced nephrotoxicity and renal carcinogenesis via amelioration of oxidative stress and modulation of multiple molecular pathways.

    Science.gov (United States)

    Siddiqi, Aisha; Hasan, Syed Kazim; Nafees, Sana; Rashid, Summya; Saidullah, Bano; Sultana, Sarwat

    2015-12-01

    In the present study, chemopreventive efficacy of hesperidin was evaluated against ferric nitrilotriacetate (Fe-NTA) induced renal oxidative stress and carcinogenesis in wistar rats. Nephrotoxicity was induced by single intraperitoneal injection of Fe-NTA (9 mg Fe/kg b.wt). Renal cancer was initiated by the administration of N-nitrosodiethylamine (DEN 200mg/kg b.wt ip) and promoted by Fe-NTA (9 mg Fe/kg b.wt ip) twice weekly for 16 weeks. Efficacy of hesperidin against Fe-NTA-induced nephrotoxicity was assessed in terms of biochemical estimation of antioxidant enzyme activities viz. reduced renal GSH, glutathione peroxidase, glutathione reductase, glutathione-S-transferase, catalase, superoxide dismutase and renal toxicity markers (BUN, Creatinine, KIM-1). Administration of Fe-NTA significantly depleted antioxidant renal armory, enhanced renal lipid peroxidation as well as the levels of BUN, creatinine and KIM-1. However, simultaneous pretreatment of hesperidin restored their levels in a dose dependent manner. Expression of apoptotic markers caspase-3, caspase-9, bax, bcl-2 and proliferative marker PCNA along with inflammatory markers (NFκB, iNOS, TNF-α) were also analysed to assess the chemopreventive potential of hesperidin in two-stage renal carcinogenesis model. Hesperidin was found to induce caspase-3, caspase-9, bax expression and downregulate bcl-2, NFκB, iNOS, TNF-α, PCNA expression. Histopathological findings further revealed hesperidin's chemopreventive efficacy by restoring the renal morphology. Our results provide a powerful evidence suggesting hesperidin to be a potent chemopreventive agent against renal carcinogenesis possibly by virtue of its antioxidant properties and by modulation of multiple molecular pathways.

  18. Evolution & Phylogenetic Analysis: Classroom Activities for Investigating Molecular & Morphological Concepts

    Science.gov (United States)

    Franklin, Wilfred A.

    2010-01-01

    In a flexible multisession laboratory, students investigate concepts of phylogenetic analysis at both the molecular and the morphological level. Students finish by conducting their own analysis on a collection of skeletons representing the major phyla of vertebrates, a collection of primate skulls, or a collection of hominid skulls.

  19. Gene Concepts in Higher Education Cell and Molecular Biology Textbooks

    Science.gov (United States)

    Albuquerque, Pitombo Maiana; de Almeida, Ana Maria Rocha; El-Hani, Nino Charbel

    2008-01-01

    Despite being a landmark of 20th century biology, the "classical molecular gene concept," according to which a gene is a stretch of DNA encoding a functional product, which may be a single polypeptide or RNA molecule, has been recently challenged by a series of findings (e.g., split genes, alternative splicing, overlapping and nested…

  20. Molecular-Scale Electronics: From Concept to Function.

    Science.gov (United States)

    Xiang, Dong; Wang, Xiaolong; Jia, Chuancheng; Lee, Takhee; Guo, Xuefeng

    2016-04-13

    Creating functional electrical circuits using individual or ensemble molecules, often termed as "molecular-scale electronics", not only meets the increasing technical demands of the miniaturization of traditional Si-based electronic devices, but also provides an ideal window of exploring the intrinsic properties of materials at the molecular level. This Review covers the major advances with the most general applicability and emphasizes new insights into the development of efficient platform methodologies for building reliable molecular electronic devices with desired functionalities through the combination of programmed bottom-up self-assembly and sophisticated top-down device fabrication. First, we summarize a number of different approaches of forming molecular-scale junctions and discuss various experimental techniques for examining these nanoscale circuits in details. We then give a full introduction of characterization techniques and theoretical simulations for molecular electronics. Third, we highlight the major contributions and new concepts of integrating molecular functionalities into electrical circuits. Finally, we provide a critical discussion of limitations and main challenges that still exist for the development of molecular electronics. These analyses should be valuable for deeply understanding charge transport through molecular junctions, the device fabrication process, and the roadmap for future practical molecular electronics.

  1. Poly(ADP-ribosyl)ation in carcinogenesis.

    Science.gov (United States)

    Masutani, Mitsuko; Fujimori, Hiroaki

    2013-12-01

    Cancer develops through diverse genetic, epigenetic and other changes, so-called 'multi-step carcinogenesis', and each cancer harbors different alterations and properties. Here in this article we review how poly(ADP-ribosyl)ation is involved in multi-step and diverse pathways of carcinogenesis. Involvement of poly- and mono-ADP-ribosylation in carcinogenesis has been studied at molecular and cellular levels, and further by animal models and human genetic approaches. PolyADP-ribosylation acts in DNA damage repair response and maintenance mechanisms of genomic stability. Several DNA repair pathways, including base-excision repair and double strand break repair pathways, involve PARP and PARG functions. These care-taker functions of poly(ADP-ribosyl)ation suggest that polyADP-ribosyation may mainly act in a tumor suppressive manner because genomic instability caused by defective DNA repair response could serve as a driving force for tumor progression, leading to invasion, metastasis and relapse of cancer. On the other hand, the new concept of 'synthetic lethality by PARP inhibition' suggests the significance of PARP activities for survival of cancer cells that harbor defects in DNA repair. Accumulating evidence has revealed that some PARP family molecules are involved in various signaling cascades other than DNA repair, including epigenetic and transcriptional regulations, inflammation/immune response and epithelial-mesenchymal transition, suggesting that poly(ADP-ribosyl)ation both promotes and suppresses carcinogenic processes depending on the conditions. Expanding understanding of poly(ADP-ribosyl)ation suggests that strategies to achieve cancer prevention targeting poly(ADP-ribosyl)ation for genome protection against life-long exposure to environmental carcinogens and endogenous carcinogenic stimuli.

  2. Molecular Tissue Engineering:Concepts,Status and Challenge

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Tissue engineering has confronted many difficulties mainly as follows:1)How to modulate the adherence,proliferation,and oriented differentiation of seed cells, especially that of stemcells. 2) Massive preparation and sustained controllable delivery of tissue inducing factors or plasmid DNA, such as growth factors, angiogenesis stimulators,and so on. 3) Development of "intelligent biomimetic materials" as extracellular matrix with a good superficial and structural compatibility as well as biological activity to stimulate predictable, controllable and desirable responses under defined conditions.Molecular biology is currently one of the most exciting fields of research across life sciences,and the advances in it also bring a bright future for tissue engineering to overcome these difficulties.In recent years,tissue engineering benefits a lot from molecular biology.Only a comprehensive understanding of the involved ingredients of tissue engineering (cells,tissue inducing factors,genes,biomaterials) and the subtle relationships between them at molecular level can lead to a successful manipulation of reparative processes and a better biological substitute.Molecular tissue engineering,the offspring of the tissue engineering and molecular biology,has gained an increasing importance in recent years.It offers the promise of not simply replacing tissue,but improving the restoration.The studies presented in this article put forward this new concept for the first time and provide an insight into the basic principles,status and challenges of this emerging technology.

  3. Molecular conservation of estrogen-response associated with cell cycle regulation, hormonal carcinogenesis and cancer in zebrafish and human cancer cell lines

    Directory of Open Access Journals (Sweden)

    Govindarajan Kunde R

    2011-05-01

    Full Text Available Abstract Background The zebrafish is recognized as a versatile cancer and drug screening model. However, it is not known whether the estrogen-responsive genes and signaling pathways that are involved in estrogen-dependent carcinogenesis and human cancer are operating in zebrafish. In order to determine the potential of zebrafish model for estrogen-related cancer research, we investigated the molecular conservation of estrogen responses operating in both zebrafish and human cancer cell lines. Methods Microarray experiment was performed on zebrafish exposed to estrogen (17β-estradiol; a classified carcinogen and an anti-estrogen (ICI 182,780. Zebrafish estrogen-responsive genes sensitive to both estrogen and anti-estrogen were identified and validated using real-time PCR. Human homolog mapping and knowledge-based data mining were performed on zebrafish estrogen responsive genes followed by estrogen receptor binding site analysis and comparative transcriptome analysis with estrogen-responsive human cancer cell lines (MCF7, T47D and Ishikawa. Results Our transcriptome analysis captured multiple estrogen-responsive genes and signaling pathways that increased cell proliferation, promoted DNA damage and genome instability, and decreased tumor suppressing effects, suggesting a common mechanism for estrogen-induced carcinogenesis. Comparative analysis revealed a core set of conserved estrogen-responsive genes that demonstrate enrichment of estrogen receptor binding sites and cell cycle signaling pathways. Knowledge-based and network analysis led us to propose that the mechanism involving estrogen-activated estrogen receptor mediated down-regulation of human homolog HES1 followed by up-regulation cell cycle-related genes (human homologs E2F4, CDK2, CCNA, CCNB, CCNE, is highly conserved, and this mechanism may involve novel crosstalk with basal AHR. We also identified mitotic roles of polo-like kinase as a conserved signaling pathway with multiple entry

  4. The molecular biology capstone assessment: a concept assessment for upper-division molecular biology students.

    Science.gov (United States)

    Couch, Brian A; Wood, William B; Knight, Jennifer K

    2015-03-02

    Measuring students' conceptual understandings has become increasingly important to biology faculty members involved in evaluating and improving departmental programs. We developed the Molecular Biology Capstone Assessment (MBCA) to gauge comprehension of fundamental concepts in molecular and cell biology and the ability to apply these concepts in novel scenarios. Targeted at graduating students, the MBCA consists of 18 multiple-true/false (T/F) questions. Each question consists of a narrative stem followed by four T/F statements, which allows a more detailed assessment of student understanding than the traditional multiple-choice format. Questions were iteratively developed with extensive faculty and student feedback, including validation through faculty reviews and response validation through student interviews. The final assessment was taken online by 504 students in upper-division courses at seven institutions. Data from this administration indicate that the MBCA has acceptable levels of internal reliability (α=0.80) and test-retest stability (r=0.93). Students achieved a wide range of scores with a 67% overall average. Performance results suggest that students have an incomplete understanding of many molecular biology concepts and continue to hold incorrect conceptions previously documented among introductory-level students. By pinpointing areas of conceptual difficulty, the MBCA can provide faculty members with guidance for improving undergraduate biology programs.

  5. Molecular Theory of the Living Cell Concepts, Molecular Mechanisms, and Biomedical Applications

    CERN Document Server

    Ji, Sungchul

    2012-01-01

    This book presents a comprehensive molecular theory of the living cell based on over thirty concepts, principles and laws imported from thermodynamics, statistical mechanics, quantum mechanics, chemical kinetics, informatics, computer science, linguistics, semiotics, and philosophy. The author formulates physically, chemically and enzymologically realistic molecular mechanisms to account for the basic living processes such as ligand-receptor interactions, protein folding, single-molecule enzymic catalysis, force-generating mechanisms in molecular motors, signal transduction, regulation of the genome-wide RNA metabolism, morphogenesis, the micro-macro coupling in coordination dynamics, the origin of life, and the mechanisms of biological evolution itself. Possible solutions to basic and practical problems facing contemporary biology and biomedical sciences have been suggested, including pharmacotheragnostics and personalized medicine.

  6. Fetal cell carcinogenesis of the thyroid: a modified theory based on recent evidence.

    Science.gov (United States)

    Takano, Toru

    2014-01-01

    Thyroid cancer cells were believed to be generated by multi-step carcinogenesis, in which cancer cells are derived from thyrocytes, via multiple incidences of damage to their genome, especially in oncogenes or anti-oncogenes that accelerate proliferation or foster malignant phenotypes, such as the ability to invade the surrounding tissue or metastasize to distant organs, until a new hypothesis, fetal cell carcinogenesis, was presented. In fetal cell carcinogenesis, thyroid tumor cells are assumed to be derived from three types of fetal thyroid cell which only exist in fetuses or young children, namely, thyroid stem cells (TSCs), thyroblasts and prothyrocytes, by proliferation without differentiation. Genomic alternations, such as RET/PTC and PAX8-PPARγ1 rearrangements and a mutation in the BRAF gene, play an oncogenic role by preventing thyroid fetal cells from differentiating. Fetal cell carcinogenesis effectively explains recent molecular and clinical evidence regarding thyroid cancer, including thyroid cancer initiating cells (TCICs), and it underscores the importance of identifying a stem cells and clarifying the molecular mechanism of organ development in cancer research. It introduces three important concepts, the reverse approach, stem cell crisis and mature and immature cancers. Further, it implies that analysis of a small population of cells in a cancer tissue will be a key technique in establishing future laboratory tests. In the contrary, mass analysis such as gene expression profiling, whole genomic scan, and proteomics analysis may have definite limitations since they can only provide information based on many cells.

  7. Recent Research Progress in Molecular Mechanisms of Cadmium Induced Carcinogenesis%镉致癌的分子机制研究进展

    Institute of Scientific and Technical Information of China (English)

    吴婧; 董欣敏; 郑燕芳; 张积仁

    2015-01-01

    Cadmium (Cd) is a ubiquitous environmental heavy metal pollutant which causes increasing worldwide concern. In the general population, exposure to cadmium occurs primarily through dietary sources, cigarette smok-ing, and drinking water. Cadmium has been classified as a human carcinogen by the international agency for re-search on cancer (IARC). In 1993, its carcinogenicity has been long established;most evidence is available for ele-vated risk for lung cancer, prostate cancer, breast cancer, gastroenteric cancer and so on. But the underlying mecha-nisms of cadmium carcinogenesis are still not clear. Many studies have been demonstrated that Cd induces cancer by multiple mechanisms:induction of oxidative stress, inhibition of DNA damage repair as well as apoptosis, aber-rant methylation and gene expression, resulting in cell cycle arrest, as a metalloestrogen, promotion of cancer stem cell growth and induction of cancer via chronic inflammation. This review summarizes the recent advances in the carcinogenic mechanism of cadmium on the molecular medicine level.%镉是一种无处不在的重金属环境污染物,广泛用于工业环境中。普通人主要通过摄食、吸烟及饮水等方式摄入镉。1993年国际肿瘤研究机构(IARC)就已将镉及其化合物列为第1类人致癌物,镉的致癌性被广泛研究,大量研究发现镉会提高肺癌、前列腺癌、乳腺癌、消化道肿瘤等肿瘤的患病风险。但至目前为止,镉的致癌分子机制尚不清楚。大量研究认为镉通过以下几方面致癌:氧化应激、抑制DNA损伤修复、DNA异常甲基化、抑制细胞凋亡、影响细胞周期调控、致多种基因异常表达、雌激素样效应、促进肿瘤干细胞生长、慢性炎症刺激。

  8. Radiogenic cell transformation and carcinogenesis

    Science.gov (United States)

    Yang, T. C.; Georgy, K. A.; Mei, M.; Durante, M.; Craise, L. M.

    1995-01-01

    Radiation carcinogenesis is one of the major biological effects considered important in the risk assessment for space travel. Various biological model systems, including both cultured cells and animals, have been found useful for studying the carcinogenic effects of space radiations, which consist of energetic electrons, protons and heavy ions. The development of techniques for studying neoplastic cell transformation in culture has made it possible to examine the cellular and molecular mechanisms of radiation carcinogenesis. Cultured cell systems are thus complementary to animal models. Many investigators have determined the oncogenic effects of ionizing and nonionizing radiation in cultured mammalian cells. One of the cell systems used most often for radiation transformation studies is mouse embryonic cells (C3H10T1/2), which are easy to culture and give good quantitative dose-response curves. Relative biological effectiveness (RBE) for heavy ions with various energies and linear energy transfer (LET) have been obtained with this cell system. Similar RBE and LET relationship was observed by investigators for other cell systems. In addition to RBE measurements, fundamental questions on repair of sub- and potential oncogenic lesions, direct and indirect effect, primary target and lesion, the importance of cell-cell interaction and the role of oncogenes and tumor suppressor genes in radiogenic carcinogenesis have been studied, and interesting results have been found. Recently several human epithelial cell systems have been developed, and ionizing radiation have been shown to transform these cells. Oncogenic transformation of these cells, however, requires a long expression time and/or multiple radiation exposures. Limited experimental data indicate high-LET heavy ions can be more effective than low-LET radiation in inducing cell transformation. Cytogenetic and molecular analyses can be performed with cloned transformants to provide insights into basic genetic

  9. A Systems Approach to Radiation Carcinogenesis

    Science.gov (United States)

    Hlatky, Lynn

    Understanding carcinogenesis risk is complicated by a number of factors, among these the lack of a common platform to integrate and analyze the available data, and the inherently systemsbiologic nature of the problem. We have investigated mechanistic approaches to radiogenic risk estimation that draw on unifying biological principles and incorporate data from multiscale sources. The resultant modeling takes into account that carcinogenesis is a multi-scale phenomenon, critically influenced by determinants not only at the molecular level, but at the cell and tissue-levels as well. To account for cell-level carcinogenesis progression as influenced by inter-tissue signaling, we have developed a dynamic carrying capacity construct that couples the growth of a tumor with the degree of induced vascularization. We have also characterized the molecular responses to radiation incorporating tissue-level angiogenesis implications, and have found striking radiation-quality-dependent responses. The molecular-level events of initiation and promotion are considered in our Two-Stage Logistic model, while incorporating in a rudimentary way the larger-scale growth-limiting role of cell-cell interactions. These and other recent studies undertaken to elaborate radiation-induced carcinogenesis are discussed, in pursuit of a more complete paradigm for understanding radiation induction of cancer and the consequent risk.

  10. Environmental and chemical carcinogenesis.

    Science.gov (United States)

    Wogan, Gerald N; Hecht, Stephen S; Felton, James S; Conney, Allan H; Loeb, Lawrence A

    2004-12-01

    People are continuously exposed exogenously to varying amounts of chemicals that have been shown to have carcinogenic or mutagenic properties in experimental systems. Exposure can occur exogenously when these agents are present in food, air or water, and also endogenously when they are products of metabolism or pathophysiologic states such as inflammation. It has been estimated that exposure to environmental chemical carcinogens may contribute significantly to the causation of a sizable fraction, perhaps a majority, of human cancers, when exposures are related to "life-style" factors such as diet, tobacco use, etc. This chapter summarizes several aspects of environmental chemical carcinogenesis that have been extensively studied and illustrates the power of mechanistic investigation combined with molecular epidemiologic approaches in establishing causative linkages between environmental exposures and increased cancer risks. A causative relationship between exposure to aflatoxin, a strongly carcinogenic mold-produced contaminant of dietary staples in Asia and Africa, and elevated risk for primary liver cancer has been demonstrated through the application of well-validated biomarkers in molecular epidemiology. These studies have also identified a striking synergistic interaction between aflatoxin and hepatitis B virus infection in elevating liver cancer risk. Use of tobacco products provides a clear example of cancer causation by a life-style factor involving carcinogen exposure. Tobacco carcinogens and their DNA adducts are central to cancer induction by tobacco products, and the contribution of specific tobacco carcinogens (e.g. PAH and NNK) to tobacco-induced lung cancer, can be evaluated by a weight of evidence approach. Factors considered include presence in tobacco products, carcinogenicity in laboratory animals, human uptake, metabolism and adduct formation, possible role in causing molecular changes in oncogenes or suppressor genes, and other relevant data

  11. Liver Development, Regeneration, and Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Janet W. C. Kung

    2010-01-01

    Full Text Available The identification of putative liver stem cells has brought closer the previously separate fields of liver development, regeneration, and carcinogenesis. Significant overlaps in the regulation of these processes are now being described. For example, studies in embryonic liver development have already provided the basis for directed differentiation of human embryonic stem cells and induced pluripotent stem cells into hepatocyte-like cells. As a result, the understanding of the cell biology of proliferation and differentiation in the liver has been improved. This knowledge can be used to improve the function of hepatocyte-like cells for drug testing, bioartificial livers, and transplantation. In parallel, the mechanisms regulating cancer cell biology are now clearer, providing fertile soil for novel therapeutic approaches. Recognition of the relationships between development, regeneration, and carcinogenesis, and the increasing evidence for the role of stem cells in all of these areas, has sparked fresh enthusiasm in understanding the underlying molecular mechanisms and has led to new targeted therapies for liver cirrhosis and primary liver cancers.

  12. Essential concepts and underlying theories from physics, chemistry, and mathematics for "biochemistry and molecular biology" majors.

    Science.gov (United States)

    Wright, Ann; Provost, Joseph; Roecklein-Canfield, Jennifer A; Bell, Ellis

    2013-01-01

    Over the past two years, through an NSF RCN UBE grant, the ASBMB has held regional workshops for faculty members from around the country. The workshops have focused on developing lists of Core Principles or Foundational Concepts in Biochemistry and Molecular Biology, a list of foundational skills, and foundational concepts from Physics, Chemistry, and Mathematics that all Biochemistry or Molecular Biology majors must understand to complete their major coursework. The allied fields working group created a survey to validate foundational concepts from Physics, Chemistry, and Mathematics identified from participant feedback at various workshops. One-hundred twenty participants responded to the survey and 68% of the respondents answered yes to the question: "We have identified the following as the core concepts and underlying theories from Physics, Chemistry, and Mathematics that Biochemistry majors or Molecular Biology majors need to understand after they complete their major courses: 1) mechanical concepts from Physics, 2) energy and thermodynamic concepts from Physics, 3) critical concepts of structure from chemistry, 4) critical concepts of reactions from Chemistry, and 5) essential Mathematics. In your opinion, is the above list complete?" Respondents also delineated subcategories they felt should be included in these broad categories. From the results of the survey and this analysis the allied fields working group constructed a consensus list of allied fields concepts, which will help inform Biochemistry and Molecular Biology educators when considering the ASBMB recommended curriculum for Biochemistry or Molecular Biology majors and in the development of appropriate assessment tools to gauge student understanding of how these concepts relate to biochemistry and molecular biology.

  13. Essential Concepts and Underlying Theories from Physics, Chemistry, and Mathematics for "Biochemistry and Molecular Biology" Majors

    Science.gov (United States)

    Wright, Ann; Provost, Joseph; Roecklein-Canfield, Jennifer A.; Bell, Ellis

    2013-01-01

    Over the past two years, through an NSF RCN UBE grant, the ASBMB has held regional workshops for faculty members from around the country. The workshops have focused on developing lists of Core Principles or Foundational Concepts in Biochemistry and Molecular Biology, a list of foundational skills, and foundational concepts from Physics, Chemistry,…

  14. Clusters of Concepts in Molecular Genetics: A Study of Swedish Upper Secondary Science Students' Understanding

    Science.gov (United States)

    Gericke, Niklas; Wahlberg, Sara

    2013-01-01

    To understand genetics, students need to be able to explain and draw connections between a large number of concepts. The purpose of the study reported herein was to explore the way upper secondary science students reason about concepts in molecular genetics in order to understand protein synthesis. Data were collected by group interviews. Concept…

  15. A general concept for molecular biology of cancer.

    Science.gov (United States)

    Busch, H

    1976-11-01

    The demonstrations that "fetal" isozymes and other fetal or "oncodevelopmental" antigens are present in tumor cells has led to the general concept that genes normally silent in adult tissues are activated during the neoplastic process. Recent evidence that some chromatin proteins of tumor cells are fetal antigens has suggested that some of the "switches" involved in gene activation for tumor growth may also be fetal or oncodevelopmental. These results have led to current theoretical concept that fetal gene derepressors interact with the genome to produce messenger RNA for the protein products involved for growth, invasiveness, and metastasis. These processes may not be controllable in adult cells because of the lack of inhibitors, which were present during embryonic development but are not produced in adult tissues.

  16. Tangible Models and Haptic Representations Aid Learning of Molecular Biology Concepts

    Science.gov (United States)

    Johannes, Kristen; Powers, Jacklyn; Couper, Lisa; Silberglitt, Matt; Davenport, Jodi

    2016-01-01

    Can novel 3D models help students develop a deeper understanding of core concepts in molecular biology? We adapted 3D molecular models, developed by scientists, for use in high school science classrooms. The models accurately represent the structural and functional properties of complex DNA and Virus molecules, and provide visual and haptic…

  17. Oxidative Stress and HPV Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Federico De Marco

    2013-02-01

    Full Text Available Extensive experimental work has conclusively demonstrated that infection with certain types of human papillomaviruses, the so-called high-risk human papillomavirus (HR-HPV, represent a most powerful human carcinogen. However, neoplastic growth is a rare and inappropriate outcome in the natural history of HPV, and a number of other events have to concur in order to induce the viral infection into the (very rare neoplastic transformation. From this perspective, a number of putative viral, host, and environmental co-factors have been proposed as potential candidates. Among them oxidative stress (OS is an interesting candidate, yet comparatively underexplored. OS is a constant threat to aerobic organisms being generated during mitochondrial oxidative phosphorylation, as well as during inflammation, infections, ionizing irradiation, UV exposure, mechanical and chemical stresses. Epithelial tissues, the elective target for HPV infection, are heavily exposed to all named sources of OS. Two different types of cooperative mechanisms are presumed to occur between OS and HPV: I The OS genotoxic activity and the HPV-induced genomic instability concur independently to the generation of the molecular damage necessary for the emergence of neoplastic clones. This first mode is merely a particular form of co-carcinogenesis; and II OS specifically interacts with one or more molecular stages of neoplastic initiation and/or progression induced by the HPV infection. This manuscript was designed to summarize available data on this latter hypothesis. Experimental data and indirect evidences on promoting the activity of OS in viral infection and viral integration will be reviewed. The anti-apoptotic and pro-angiogenetic role of NO (nitric oxide and iNOS (inducible nitric oxide synthase will be discussed together with the OS/HPV cooperation in inducing cancer metabolism adaptation. Unexplored/underexplored aspects of the OS interplay with the HPV-driven carcinogenesis

  18. Oxidative damage and carcinogenesis

    OpenAIRE

    2012-01-01

    Oxygen is an essential element to conduct life processes but some of the metabolic byproducts e.g. reactive oxygen species (ROS), are toxic for living organisms. Endogenous ROS are produced e.g. reduction of dioxygen; some exogenous sources of radicals also exist, including nicotine and ionizing radiation. Reactive oxygen species include superoxide anion, hydroxyl radical, singlet oxygen, hydrogen peroxide and hypochlorous acid. Carcinogenesis is a multistep process. The exact reasons for the...

  19. Sawmill chemicals and carcinogenesis.

    OpenAIRE

    Huff, J

    2001-01-01

    Workers in wood industries are exposed to variable medleys of chemicals, both natural and synthetic. Additional exposures include fungi, bacteria, bark and wood dusts, solvents, paints, and various other wood coatings. These individual and conglomerate exposures have been associated with diverse occupational illnesses and hazards, including cancers. In this commentary, I summarize both experimental and epidemiologic carcinogenesis results for several chemicals used in the wood industry, as we...

  20. Molecular complexity of primary open angle glaucoma: current concepts

    Indian Academy of Sciences (India)

    Kunal Ray; Suddhasil Mookherjee

    2009-12-01

    Glaucoma is a group of heterogeneous optic neuropathies with complex genetic basis. Among the three principle subtypes of glaucoma, primary open angle glaucoma (POAG) occurs most frequently. Till date, 25 loci have been found to be linked to POAG. However, only three underlying genes (Myocilin, Optineurin and WDR36) have been identified. In addition, at least 30 other genes have been reported to be associated with POAG. Despite strong genetic influence in POAG pathogenesis, only a small part of the disease can be explained in terms of genetic aberration. Current concepts of glaucoma pathogenesis suggest it to be a neurodegenerative disorder which is triggered by different factors including mechanical stress due to intra-ocular pressure, reduced blood flow to retina, reperfusion injury, oxidative stress, glutamate excitotoxicity, and aberrant immune response. Here we present a mechanistic overview of potential pathways and crosstalk between them operating in POAG pathogenesis.

  1. [Cyclooxygenase 2 and carcinogenesis].

    Science.gov (United States)

    Rodrigues, Sylvie; Bruyneel, Erik; Rodrigue, Christelle M; Shahin, Emami; Gespach, Christian

    2004-05-01

    The membrane glycoprotein Cox2 is regulated at transcriptional and post-transcriptional levels by pro-inflammatory agents, cytokines, growth factors, oncogenes, and tumor-promoters. Cox2 is expressed during early stages of colorectal carcinogenesis from the premalignant adenoma stage, and adenocarcinomas of stomach, colon, breast, lung and prostate. Its expression is detected in neoplastic, inflammatory, endothelial and stromal cells. Cox2 is involved in the conversion of arachidonic acid into prostaglandins and thromboxanes, as well as the synthesis of malonaldehyde (MDA, a mutagen) and the production of hydrogen peroxide, which promotes carcinogenesis. The Cox2 products act in turn on serpentine receptors coupled to heterotrimeric G-proteins (R-TXA2, R-PG) that are connected to signaling elements implicated in oncogenesis. Thus, Cox2 plays a key role in early stages of carcinogenesis by promoting the proliferation of tumoral cells and their resistance to apoptosis, as well as angiogenesis, tumor cell invasion and setting up of the metastatic process. These mechanisms establish the rationale behind the therapeutic targeting of Cox2 in human solid tumors.

  2. Genomic Instability and Colon Carcinogenesis: From the Perspective of Genes

    OpenAIRE

    RAO, CHINTHALAPALLY V.; Yamada, Hiroshi Y.

    2013-01-01

    Colon cancer is the second most lethal cancer; approximately 600,000 people die of it annually in the world. Colon carcinogenesis generally follows a slow and stepwise process of accumulation of mutations under the influence of environmental and epigenetic factors. To adopt a personalized (tailored) cancer therapy approach and to improve current strategies for prevention, diagnosis, prognosis, and therapy overall, advanced understanding of molecular events associated with colon carcinogenesis...

  3. Shaping mitotic chromosomes: From classical concepts to molecular mechanisms.

    Science.gov (United States)

    Kschonsak, Marc; Haering, Christian H

    2015-07-01

    How eukaryotic genomes are packaged into compact cylindrical chromosomes in preparation for cell divisions has remained one of the major unsolved questions of cell biology. Novel approaches to study the topology of DNA helices inside the nuclei of intact cells, paired with computational modeling and precise biomechanical measurements of isolated chromosomes, have advanced our understanding of mitotic chromosome architecture. In this Review Essay, we discuss - in light of these recent insights - the role of chromatin architecture and the functions and possible mechanisms of SMC protein complexes and other molecular machines in the formation of mitotic chromosomes. Based on the information available, we propose a stepwise model of mitotic chromosome condensation that envisions the sequential generation of intra-chromosomal linkages by condensin complexes in the context of cohesin-mediated inter-chromosomal linkages, assisted by topoisomerase II. The described scenario results in rod-shaped metaphase chromosomes ready for their segregation to the cell poles.

  4. Metaphorical concepts in molecular biology students’ texts – a way to improve subject-matter understanding

    Directory of Open Access Journals (Sweden)

    Alexandra Fredriksson

    2016-04-01

    Full Text Available Earlier research brings evidence that metaphors facilitate our understanding of the world. In this study we explore Bachelor students’ popular science articles on molecular biology with the aim to determine the frequency and nature of metaphorical concepts used in the articles. For this purpose, a comparative metaphor analysis of students’ texts was conducted. The results show that only few students (5 out of 47 use metaphorical concepts when writing about complex molecular biological mechanisms to non-specialist readers. We discuss that the use of metaphors not only reflect, but may also support, the writer’s subject understanding, especially when metaphorical concepts are created by the writer herself. We suggest that the invention of metaphorical concepts when explaining subject-matter to a layman could be a way for students to improve their subject understanding.

  5. Molecular concepts of water splitting. Nature's approach

    Energy Technology Data Exchange (ETDEWEB)

    Cox, Nicholas; Lubitz, Wolfgang [Max-Planck-Institut fuer Chemische Energiekonversion, Muelheim an der Ruhr (Germany)

    2013-07-01

    Based on studies of natural systems, much has also been learned concerning the design principles required for biomimetic catalysis of water splitting and hydrogen evolution. In summary, these include use of abundant and inexpensive metals, the effective protection of the active sites in functional environments, repair/replacement of active components in case of damage, and the optimization of reaction rates. Biomimetic chemistry aims to mimic all these features; many labs are working toward this goal by developing new approaches in the design and synthesis of such systems, encompassing not only the catalytic center, but also smart matrices and assembly via self-organization. More stable catalysts that do not require self-repair may be obtained from fully artificial (inorganic) catalytic systems that are totally different from the biological ones and only apply some basic principles learned from nature. Metals other than Mn/Ca, Fe, and Ni could be used (e.g. Co) in new ligand spheres and other matrices. For light harvesting, charge separation/stabilization, and the effective coupling of the oxidizing/reducing equivalents to the redox catalysts, different methods have been proposed - for example, covalently linked molecular donor-acceptor systems, photo-voltaic devices, semiconductor-based systems, and photoactive metal complexes. The aim of all these approaches is to develop catalytic systems that split water with sunlight into hydrogen and oxygen while displaying high efficiency and long-term stability. Such a system - either biological, biomimetic, or bioinspired - has the potential to be used on a large scale to produce 'solar fuels' (e.g. hydrogen or secondary products thereof). (orig.)

  6. The AOM/DSS murine model for the study of colon carcinogenesis: From pathways to diagnosis and therapy studies

    Science.gov (United States)

    Robertis, Mariangela De; Massi, Emanuela; Poeta, Maria Luana; Carotti, Simone; Morini, Sergio; Cecchetelli, Loredana; Signori, Emanuela; Fazio, Vito Michele

    2011-01-01

    Colorectal cancer (CRC) is a major health problem in industrialized countries. Although inflammation-linked carcinogenesis is a well accepted concept and is often observed within the gastrointestinal tract, the underlying mechanisms remain to be elucidated. Inflammation can indeed provide initiating and promoting stimuli and mediators, generating a tumour-prone microenvironment. Many murine models of sporadic and inflammation-related colon carcinogenesis have been developed in the last decade, including chemically induced CRC models, genetically engineered mouse models, and xenoplants. Among the chemically induced CRC models, the combination of a single hit of azoxymethane (AOM) with 1 week exposure to the inflammatory agent dextran sodium sulphate (DSS) in rodents has proven to dramatically shorten the latency time for induction of CRC and to rapidly recapitulate the aberrant crypt foci–adenoma–carcinoma sequence that occurs in human CRC. Because of its high reproducibility and potency, as well as the simple and affordable mode of application, the AOM/DSS has become an outstanding model for studying colon carcinogenesis and a powerful platform for chemopreventive intervention studies. In this article we highlight the histopathological and molecular features and describe the principal genetic and epigenetic alterations and inflammatory pathways involved in carcinogenesis in AOM/DSS–treated mice; we also present a general overview of recent experimental applications and preclinical testing of novel therapeutics in the AOM/DSS model. PMID:21483655

  7. Oxidants, antioxidants and carcinogenesis.

    Science.gov (United States)

    Ray, Gibanananda; Husain, Syed Akhtar

    2002-11-01

    Reactive oxygen metabolites (ROMs), such as superoxide anions (O2*-) hydrogen peroxide (H2O2), and hydroxyl radical (*OH), malondialdehyde (MDA) and nitric oxide (NO) are directly or indirectly involved in multistage process of carcinogenesis. They are mainly involved in DNA damage leading sometimes to mutations in tumour suppressor genes. They also act as initiator and/or promotor in carcinogenesis. Some of them are mutagenic in mammalian systems. O2*-, H2O2 and *OH are reported to be involved in higher frequencies of sister chromatid exchanges (SCEs) and chromosome breaks and gaps (CBGs). MDA, a bi-product of lipid peroxidation (LPO), is said to be involved in DNA adduct formations, which are believed to be responsible for carcinogenesis. NO, on the other hand, plays a duel role in cancer. At high concentration it kills tumour cells, but at low concentration it promotes tumour growth and metastasis. It causes DNA single and double strand breaks. The metabolites of NO such as peroxynitrite (OONO-) is a potent mutagen that can induce transversion mutations. NO can stimulate O2*-/H2O2/*OH-induced LPO. These deleterious actions of oxidants can be countered by antioxidant defence system in humans. There are first line defense antioxidants such as superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT). SOD converts O2*- to H2O2, which is further converted to H2O with the help of GPx and CAT. SOD inhibits *OH production. SOD also act as antipoliferative agent, anticarcinogens, and inhibitor at initiation and promotion/transformation stage in carcinogenesis. GPx is another antioxidative enzyme which catalyses to convert H2O2, to H2O. The most potent enzyme is CAT. GPx and CAT are important in the inactivation of many environmental mutagens. CAT is also found to reduce the SCE levels and chromosomal aberrations. Antioxidative vitamins such as vitamin A, E, and C have a number of biological activities such as immune stimulation, inhibition of

  8. Genetic and epigenetic alterations in pancreatic carcinogenesis.

    Science.gov (United States)

    Delpu, Yannick; Hanoun, Naïma; Lulka, Hubert; Sicard, Flavie; Selves, Janick; Buscail, Louis; Torrisani, Jérôme; Cordelier, Pierre

    2011-03-01

    Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers worldwide. Despite significant progresses in the last decades, the origin of this cancer remains unclear and no efficient therapy exists. PDAC does not arise de novo: three remarkable different types of pancreatic lesions can evolve towards pancreatic cancer. These precursor lesions include: Pancreatic intraepithelial neoplasia (PanIN) that are microscopic lesions of the pancreas, Intraductal Papillary Mucinous Neoplasms (IPMN) and Mucinous Cystic Neoplasms (MCN) that are both macroscopic lesions. However, the cellular origin of these lesions is still a matter of debate. Classically, neoplasm initiation or progression is driven by several genetic and epigenetic alterations. The aim of this review is to assemble the current information on genetic mutations and epigenetic disorders that affect genes during pancreatic carcinogenesis. We will further discuss the interest of the genetic and epigenetic alterations for the diagnosis and prognosis of PDAC. Large genetic alterations (chromosomal deletion/amplification) and single point mutations are well described for carcinogenesis inducers. Mutations classically occur within key regions of the genome. Consequences are various and include activation of mitogenic pathways or silencing of apoptotic processes. Alterations of K-RAS, P16 and DPC4 genes are frequently observed in PDAC samples and have been described to arise gradually during carcinogenesis. DNA methylation is an epigenetic process involved in imprinting and X chromosome inactivation. Alteration of DNA methylation patterns leads to deregulation of gene expression, in the absence of mutation. Both genetic and epigenetic events influence genes and non-coding RNA expression, with dramatic effects on proliferation, survival and invasion. Besides improvement in our fundamental understanding of PDAC development, highlighting the molecular alterations that occur in pancreatic carcinogenesis could

  9. Tensions and Opportunities in Convergence: Shifting Concepts of Disease in Emerging Molecular Medicine

    NARCIS (Netherlands)

    Boenink, Marianne

    2009-01-01

    The convergence of biomedical sciences with nanotechnology as well as ICT has created a new wave of biomedical technologies, resulting in visions of a ‘molecular medicine’. Since novel technologies tend to shift concepts of disease and health, this paper investigates how the emerging field of molecu

  10. Foundational Concepts and Underlying Theories for Majors in "Biochemistry and Molecular Biology"

    Science.gov (United States)

    Tansey, John T.; Baird, Teaster, Jr.; Cox, Michael M.; Fox, Kristin M.; Knight, Jennifer; Sears, Duane; Bell, Ellis

    2013-01-01

    Over the past two years, through an NSF RCN UBE grant, the ASBMB has held regional workshops for faculty members and science educators from around the country that focused on identifying: 1) core principles of biochemistry and molecular biology, 2) essential concepts and underlying theories from physics, chemistry, and mathematics, and 3)…

  11. Molecular Diagnostics for Complex Pest and Disease Resistance and Tuber Quality Traits: Concept, Achievements and Perspectives

    NARCIS (Netherlands)

    Gebhardt, C.; Urbany, C.; Li, L.; Stich, B.; Caldas Paulo, M.J.; Draffehn, A.; Ballvora, A.

    2011-01-01

    We summarize the concept of molecular diagnostic of complex traits related to pest and disease resistance and to tuber quality of potato, and describe recent achievements and perspectives. Many potato characteristics are controlled by multiple genetic and environmental factors. Knowing the genes and

  12. Oral Carcinogenesis and Oral Cancer Chemoprevention: A Review

    Directory of Open Access Journals (Sweden)

    Takuji Tanaka

    2011-01-01

    Full Text Available Oral cancer is one of the major global threats to public health. The development of oral cancer is a tobacco-related multistep and multifocal process involving field cancerization and carcinogenesis. The rationale for molecular-targeted prevention of oral cancer is promising. Biomarkers of genomic instability, including aneuploidy and allelic imbalance, are possible to measure the cancer risk of oral premalignancies. Understanding of the biology of oral carcinogenesis will yield important advances for detecting high-risk patients, monitoring preventive interventions, and assessing cancer risk and pharmacogenomics. In addition, novel chemopreventive agents based on molecular mechanisms and targets against oral cancers will be derived from studies using appropriate animal carcinogenesis models. New approaches, such as molecular-targeted agents and agent combinations in high-risk oral individuals, are undoubtedly needed to reduce the devastating worldwide consequences of oral malignancy.

  13. Methylation in esophageal carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    Da-Long Wu; Feng-Ying Sui; Xiao-Ming Jiang; Xiao-Hong Jiang

    2006-01-01

    Genetic abnormalities of proto-oncogenes and tumor suppressor genes have been demonstrated to be changes that are frequently involved in esophageal cancer pathogenesis. However, hypermethylation of CpG islands, an epigenetic event, is coming more and more into focus in carcinogenesis of the esophagus. Recent studies have proved that promoter hypermethylation of tumor suppressor genes is frequently observed in esophageal carcinomas and seems to play an important role in the pathogenesis of this tumor type. In this review, we will discuss current research on genes that are hypermethylated in human esophageal cancer and precancerous lesions of the esophagus. We will also discuss the potential use of hypermethylated genes as targets for detection, prognosis and treatment of esophageal cancer.

  14. [Iron function and carcinogenesis].

    Science.gov (United States)

    Akatsuka, Shinya; Toyokuni, Shinya

    2016-07-01

    Though iron is an essential micronutrient for humans, the excess state is acknowledged to be associated with oncogenesis. For example, iron overload in the liver of the patients with hereditary hemocromatosis highly increases the risk of hepatocellular carcinoma. Also, as to asbestos-related mesothelioma, such kinds of asbestos with a higher iron content are considered to be more carcinogenic. Iron is a useful element, which enables fundamental functions for life such as oxygen carrying and electron transport. However, in the situation where organisms are unable to have good control of it, iron turns into a dangerous element which catalyzes generation of reactive oxygen. In this review, I first outline the relationships between iron and cancer in general, then give an explanation about iron-related animal carcinogenesis models.

  15. Using a pharmacophore representation concept to elucidate molecular similarity of dopamine antagonists

    Science.gov (United States)

    Atlamazoglou, V.; Thireou, T.; Eliopoulos, E.

    2007-05-01

    The pharmacophoric concept plays an important role in ligand-based drug design methods to describe the similarity and diversity of molecules, and could also be exploited as a molecular representation scheme. A three-point pharmacophore method was used as a molecular representation perception. This procedure was implemented for dopamine antagonists of the D2 receptor subtype. The molecular structures of the antagonists included in this analysis were categorized into two structurally distinct classes. Using structural superposition with internal energy minimization, two pharmacophore models were deduced. Based on these two models other D2 antagonists that fulfil them were derived and studied. This procedure aided the identification of the common 3D patterns present in diverse molecules that act at the same biological target and the extraction of a common molecular framework for the two structural classes. The pharmacophoric information was found to be suitable for guiding superposition of structurally diverse molecules, using a more biologically meaningful selection of the targeting points.

  16. Materials learning from life: concepts for active, adaptive and autonomous molecular systems.

    Science.gov (United States)

    Merindol, Rémi; Walther, Andreas

    2017-01-30

    Bioinspired out-of-equilibrium systems will set the scene for the next generation of molecular materials with active, adaptive, autonomous, emergent and intelligent behavior. Indeed life provides the best demonstrations of complex and functional out-of-equilibrium systems: cells keep track of time, communicate, move, adapt, evolve and replicate continuously. Stirred by the understanding of biological principles, artificial out-of-equilibrium systems are emerging in many fields of soft matter science. Here we put in perspective the molecular mechanisms driving biological functions with the ones driving synthetic molecular systems. Focusing on principles that enable new levels of functionalities (temporal control, autonomous structures, motion and work generation, information processing) rather than on specific material classes, we outline key cross-disciplinary concepts that emerge in this challenging field. Ultimately, the goal is to inspire and support new generations of autonomous and adaptive molecular devices fueled by self-regulating chemistry.

  17. MYC and gastric adenocarcinoma carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    Danielle Queiroz Calcagno; Mariana Ferreira Leal; Paulo Pimentel Assumpcao; Marilia de Arruda Cardoso Smith; Rommel Rodriguez Burbano

    2008-01-01

    MYC is an oncogene involved in cell cycle regulation, cell growth arrest, cell adhesion, metabolism, ribosome biogenesis, protein synthesis, and mitochondrial function. It has been described as a key element of several carcinogenesis processes in humans. Many studies have shown an association between MYC deregulation and gastric cancer. MYC deregulation is also seen in gastric preneoplastic lesions and thus it may have a role in early gastric carcinogenesis. Several studies have suggested that amplification is the main mechanism of MYC deregulation in gastric cancer. In the present review, we focus on the deregulation of the MYC oncogene in gastric adenocarcinoma carcinogenesis, including its association with Helicobacter pylori (H pylori) and clinical applications.

  18. Tensions and Opportunities in Convergence: Shifting Concepts of Disease in Emerging Molecular Medicine.

    Science.gov (United States)

    Boenink, Marianne

    2009-12-01

    The convergence of biomedical sciences with nanotechnology as well as ICT has created a new wave of biomedical technologies, resulting in visions of a 'molecular medicine'. Since novel technologies tend to shift concepts of disease and health, this paper investigates how the emerging field of molecular medicine may shift the meaning of 'disease' as well as the boundary between health and disease. It gives a brief overview of the development towards and the often very speculative visions of molecular medicine. Subsequently three views of disease often used in the philosophy of medicine are briefly discussed: the ontological or neo-ontological, the physiological and the normative/holistic concepts of disease. Against this background two tendencies in the field of molecular medicine are highlighted: (1) the use of a cascade model of disease and (2) the notion of disease as a deviation from an individual pattern of functioning. It becomes clear that molecular medicine pulls conceptualizations of disease and health in several, partly opposed directions. However, the resulting tensions may also offer opportunities to steer the future of medicine in more desirable directions.

  19. Molecular motors: how to make models that can be used to convey the concept of molecular ratchets and thermal capture.

    Science.gov (United States)

    DoHarris, Lindsay; Giesler, Amanda; Humber, Brent; Sukumar, Aravin; Janssen, Luke J

    2011-06-01

    A wide variety of cellular processes use molecular motors, including processive motors that move along some form of track (e.g., myosin with actin, kinesin or dynein with tubulin) and polymerases that move along a template (e.g., DNA and RNA polymerases, ribosomes). In trying to understand how these molecular motors actually move, many apply their understanding of how man-made motors work: the latter use some form of energy to exert a force or torque on its load. However, quite a different mechanism has been proposed to possibly account for the movement of molecular motors. Rather than hydrolyzing ATP to push or pull their load, they might use their own thermal vibrational energy as well as that of their load and their environment to move the load, capturing those movements that occur along a desired vector or axis and resisting others; ATP hydrolysis is required to make backward movements impossible. This intriguing thermal capture or Brownian ratchet model is relatively more difficult to convey to students. In this report, we describe several teaching aids that are very easily constructed using widely available household materials to convey the concept of a molecular ratchet.

  20. Gene amplification in carcinogenesis

    Directory of Open Access Journals (Sweden)

    Lucimari Bizari

    2006-01-01

    Full Text Available Gene amplification increases the number of genes in a genome and can give rise to karyotype abnormalities called double minutes (DM and homogeneously staining regions (HSR, both of which have been widely observed in human tumors but are also known to play a major role during embryonic development due to the fact that they are responsible for the programmed increase of gene expression. The etiology of gene amplification during carcinogenesis is not yet completely understood but can be considered a result of genetic instability. Gene amplification leads to an increase in protein expression and provides a selective advantage during cell growth. Oncogenes such as CCND1, c-MET, c-MYC, ERBB2, EGFR and MDM2 are amplified in human tumors and can be associated with increased expression of their respective proteins or not. In general, gene amplification is associated with more aggressive tumors, metastases, resistance to chemotherapy and a decrease in the period during which the patient stays free of the disease. This review discusses the major role of gene amplification in the progression of carcinomas, formation of genetic markers and as possible therapeutic targets for the development of drugs for the treatment of some types of tumors.

  1. Studies of pancreatic carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    JI Yu-bin; PANG Lin-lin; YU Lei; YANG Hai-fan; LIU Guang-da; LI Hai-jiao

    2008-01-01

    Pancreatic carcinoma is the most common pancreatic neoplasm characterized by latentmorbidit, poor prognosis, high mortality rate and limited choice of treatment. Quite a lot studies focused on its pathogenesis, and showed molecular genetic alterations, which derived of genetic and environmental factors and played an important role in tumorigenesis. Recently, more and more findings laid particular emphasis on the changes of gene molecule and some were confirmed in vitro and in vivo. In this paper, we made a review and summarized the arked molecular changes and signalings of the four pathways to understand their functions in Pancreatic carcinoma. The most important changes concentrate on K-RAS, p16 INK4α, P53 and SMAD4 gene, secondly, the changes of pl4ARF, TGF-β, LKB1 /STK11, BRCA2 and growth factor Hedgehog and Notch path way and Telomere also play a important role in pancreatic carcinoma. The vast majority (83%) of pancreatic carcinomas had a distinctive genetic fingerprint, comprising activation of the K-ras oncogene and inactivation of the p 16 gene, generally also accompanied by alterations in the p53 gene (in 76 % of the tumors). The activation of K-ras appears nearly to be a prerequisite for the development of pancreatic carcinoma. Also, the binary alteration of K-ras and p16 is an extremely uncommon combination among other human tumor types. This particular genetic imprint of pancreatic carcinomas could have diagnostic utility in the evaluation of patients with metastatic adenocarcinoma of unknown primary origin. The evaluation of genetic alterations as they naturally occur in humantumors allows the formulation of hypotheses concerning the biological processes that involve human tumongenesis. A central tenet of tumori genesis, that positive selection is exerted upon those tumor cells that alterrate-limiting regulatory pathways, implies that mutation of one gene abrogates the need for inactivation of another gene in the same tumor suppressive pathway. It

  2. DNA methylation and carcinogenesis.

    Science.gov (United States)

    Lichtenstein, A V; Kisseljova, N P

    2001-03-01

    In the world of easy things truth is opposed to lie; in the world of complicated things one profound truth is opposed to another not less profound than the first. Neils Bohr The hypothesis of the exclusively genetic origin of cancer ("cancer is a disease of genes, a tumor without any damage to the genome does not exist") dominated in the oncology until recently. A considerable amount of data confirming this hypothesis was accumulated during the last quarter of the last century. It was demonstrated that the accumulation of damage of specific genes lies at the origin of a tumor and its following progression. The damage gives rise to structural changes in the respective proteins and, consequently, to inappropriate mitogenic stimulation of cells (activation of oncogenes) or to the inactivation of tumor suppressor genes that inhibit cell division, or to the combination of both (in most cases). According to an alternative (epigenetic) hypothesis that was extremely unpopular until recently, a tumor is caused not by a gene damage, but by an inappropriate function of genes ("cancer is a disease of gene regulation and differentiation"). However, recent studies led to the convergence of these hypotheses that initially seemed to be contradictory. It was established that both factors--genetic and epigenetic--lie at the origin of carcinogenesis. The relative contribution of each varies significantly in different human tumors. Suppressor genes and genes of repair are inactivated in tumors due to their damage or methylation of their promoters (in the latter case an "epimutation", an epigenetic equivalent of a mutation, occurs, producing the same functional consequences). It is becoming evident that not only the mutagens, but various factors influencing cell metabolism, notably methylation, should be considered as carcinogens.

  3. An Extended SNOMED CT Concept Model for Observations in Molecular Genetics

    Science.gov (United States)

    Campbell, James R.; Talmon, Geoffrey; Cushman-Vokoun, Allison; Karlsson, Daniel; Scott Campbell, W.

    2016-01-01

    Molecular genetics laboratory reports are multiplying and increasingly of clinical importance in diagnosis and treatment of cancer, infectious disease and managing of public health. Little of this data is structured or maintained in the EHR in format useful for decision support or research. Structured, computable reporting is limited by non-availability of a domain ontology for these data. The IHTSDO and Regenstrief Institute(RI) have been collaborating since 2008 to develop a unified concept model and ontology of observable entities – concepts which represent the results of laboratory and clinical observations. In this paper we report the progress we have made to apply that unified concept model to the structured recording of observations in clinical molecular genetic pathology including immunohistochemistry and sequence variant findings. The primary use case for deployment is the structured and coded reporting of Cancer checklist© and biomarker data as developed by the College of American Pathologists(CAP) with collaboration by the Royal College of Pathology(RCP). PMID:28269830

  4. Molecular detection, quantification, and isolation of Streptococcus gallolyticus bacteria colonizing colorectal tumors: inflammation-driven potential of carcinogenesis via IL-1, COX-2, and IL-8

    Directory of Open Access Journals (Sweden)

    Abdulamir Ahmed S

    2010-09-01

    Full Text Available Abstract Background Colorectal cancer (CRC has long been associated with bacteremia and/or endocarditis by Streptococcus gallolyticus member bacteria (SGMB but the direct colonization of SGMB along with its molecular carcinogenic role, if any, has not been investigated. We assessed the colonization of SGMB in CRC patients with history of bacteremia (CRC-w/bac and without history of bacteremia (CRC-wo/bac by isolating SGMB from feces, mucosal surfaces of colorectum, and colorectal tissues and detecting SGMB DNA, via PCR and in situ hybridization (ISH assays targeting SodA gene in colorectal tissues. Moreover, mRNA of IL1, IL-8, COX-2, IFN-γ, c-Myc, and Bcl-2 in colorectal tissues of studied groups was assessed via ISH and RT-PCR. Results SGMB were found to be remarkably isolated in tumorous (TU and non-tumorous (NTU tissues of CRC-w/bac, 20.5% and 17.3%, and CRC-wo/bac, 12.8% and 11.5%, respectively while only 2% of control tissues revealed SGMB (P 10 CN/g respectively, showed higher colonization in TU than in NTU and in CRC-w/bac than in CRC-wo/bac (P Conclusions The current study indicated that colorectal cancer is remarkably associated with SGMB; moreover, molecular detection of SGMB in CRC was superior to link SGMB with CRC tumors highlighting a possible direct and active role of SGMB in CRC development through most probably inflammation-based sequel of tumor development or propagation via, but not limited to, IL-1, COX-2, and IL-8.

  5. Effects of environmental stressors on histone modifications and their relevance to carcinogenesis: a systematic review.

    NARCIS (Netherlands)

    Dik, S.; Scheepers, P.T.J.; Godderis, L.

    2012-01-01

    Carcinogenesis is a complex process involving both genetic and epigenetic mechanisms. The cellular molecular epigenetic machinery, including histone modifications, is associated with changes in gene expression induced by exposure to environmental agents. In this paper, we systematically reviewed pub

  6. Helicobacter pylori in gastric carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    Hyo; Jun; Ahn; Dong; Soo; Lee

    2015-01-01

    Gastric cancer still is a major concern as the third most common cancer worldwide, despite declining rates of incidence in many Western countries. Helicobacter pylori(H. pylori) is the major cause of gastric carcinogenesis, and its infection insults gastric mucosa leading to theoccurrence of atrophic gastritis which progress to intestinal metaplasia, dysplasia, early gastric cancer, and advanced gastric cancer consequently. This review focuses on multiple factors including microbial virulence factors, host genetic factors, and environmental factors, which can heighten the chance of occurrence of gastric adenocarcinoma due to H. pylori infection. Bacterial virulence factors are key components in controlling the immune response associated with the induction of carcinogenesis, and cag A and vac A are the most well-known pathogenic factors. Host genetic polymorphisms contribute to regulating the inflammatory response to H. pylori and will become increasingly important with advancing techniques. Environmental factors such as high salt and smoking may also play a role in gastric carcinogenesis. It is important to understand the virulence factors, host genetic factors, and environmental factors interacting in the multistep process of gastric carcinogenesis. To conclude, prevention via H. pylori eradication and controlling environmental factors such as diet, smoking, and alcohol is an important strategy to avoid H. pylori-associated gastric carcinogenesis.

  7. Carcinogenesis mechanisms of Fusobacterium nucleatum.

    Science.gov (United States)

    Gholizadeh, Pourya; Eslami, Hosein; Kafil, Hossein Samadi

    2017-03-07

    Transformed cells of cancers may be related to stromal cells, immune cells, and some bacteria such as Fusobacterium nucleatum. This review aimed to evaluate carcinogenesis mechanisms of Fusobacterium spp. in the oral cavity, pancreatic and colorectal cancers. These cancers are the three of the ten most prevalence cancer in the worldwide. Recent findings demonstrated that F. nucleatum could be considered as the risk factor for these cancers. The most important carcinogenesis mechanisms of F. nucleatum are chronic infection, interaction of cell surface molecules of these bacteria with immune system and stromal cells, immune evasion and immune suppression. However, there are some uncertainty carcinogenesis mechanisms about these bacteria, but this review evaluates almost all the known mechanisms. Well-characterized virulence factors of F. nucleatum such as FadA, Fap2, LPS and cell wall extracts may act as effector molecules in the shift of normal epithelial cells to tumor cells. These molecules may provide new targets, drugs, and strategies for therapeutic intervention.

  8. Modeling Multiple Causes of Carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Jones, T D

    1999-01-24

    An array of epidemiological results and databases on test animal indicate that risk of cancer and atherosclerosis can be up- or down-regulated by diet through a range of 200%. Other factors contribute incrementally and include the natural terrestrial environment and various human activities that jointly produce complex exposures to endotoxin-producing microorganisms, ionizing radiations, and chemicals. Ordinary personal habits and simple physical irritants have been demonstrated to affect the immune response and risk of disease. There tends to be poor statistical correlation of long-term risk with single agent exposures incurred throughout working careers. However, Agency recommendations for control of hazardous exposures to humans has been substance-specific instead of contextually realistic even though there is consistent evidence for common mechanisms of toxicological and carcinogenic action. That behavior seems to be best explained by molecular stresses from cellular oxygen metabolism and phagocytosis of antigenic invasion as well as breakdown of normal metabolic compounds associated with homeostatic- and injury-related renewal of cells. There is continually mounting evidence that marrow stroma, comprised largely of monocyte-macrophages and fibroblasts, is important to phagocytic and cytokinetic response, but the complex action of the immune process is difficult to infer from first-principle logic or biomarkers of toxic injury. The many diverse database studies all seem to implicate two important processes, i.e., the univalent reduction of molecular oxygen and breakdown of aginuine, an amino acid, by hydrolysis or digestion of protein which is attendant to normal antigen-antibody action. This behavior indicates that protection guidelines and risk coefficients should be context dependent to include reference considerations of the composite action of parameters that mediate oxygen metabolism. A logic of this type permits the realistic common-scale modeling of

  9. Epigenetic alterations in gastric carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    In-Seon CHOI; Tsung-Teh WU

    2005-01-01

    Gastric cancer is believed to result in part from the accumulation of multiple genetic alterations leading to oncogene overexpression and tumor suppressor loss. Epigenetic alterations as a distinct and crucial mechanism to silence a variety of methylated tissue-specific and imprinted genes, have been extensively studied in gastric carcinoma and play important roles in gastric carcinogenesis. This review will briefly discuss the basic aspects of DNA methylation and CpG island methylation, in particular the epigenetic alterations of certain critical genes implicated in gastric carcinogenesis and its relevance of clinical implications.

  10. Aberrant DNA methylation in cervical carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    Hui-Juan Yang

    2013-01-01

    Persistent infection with high-risk types of human papillomavirus(HPV) is known to cause cervical cancer; however,additional genetic and epigenetic alterations are required for progression from precancerous disease to invasive cancer.DNA methylation is an early and frequent molecular alteration in cervical carcinogenesis.In this review,we summarize DNA methylation within the HPV genome and human genome and identify its clinical implications.Methylation of the HPV long control region (LCR) and L1 gene is common during cervical carcinogenesis and increases with the severity of the cervical neoplasm.The L1 gene of HPV16 and HPV18 is consistently hypermethylated in invasive cervical cancers and can potentially be used as a clinical marker of cancer progression.Moreover,promoters of tumor suppressor genes (TSGs) involved in many cellular pathways are methylated in cervical precursors and invasive cancers.Some are associated with squamous cell carcinomas,and others are associated with adenocarcinomas.Identification of methylated TSGs in Pap smear could be an adjuvant test in cervical cancer screening for triage of women with high-risk HPV,atypical squamous cells of undetermined significance,or low grade squamous intraepithelial lesion (LSIL).However,consistent panels must be validated for this approach to be translated to the clinic.Furthermore,reversion of methylated TSGs using demethylating drugs may be an alternative anticancer treatment,but demethylating drugs without toxic carcinogenic and mutagenic properties must be identified and validated.

  11. Plastics and carcinogenesis: The example of vinyl chloride

    Directory of Open Access Journals (Sweden)

    Paul Wesley Brandt-Rauf

    2012-01-01

    Full Text Available The manufacture, use and disposal of various plastics can pose numerous health risks, including the risk of cancer. A model example of carcinogenic risk from plastics is provided by polyvinyl chloride, since it is composed of the known human carcinogen vinyl chloride (VC. In recent years, much has been learned about the molecular biological pathways of VC carcinogenesis. This has led to molecular epidemiologic studies of VC carcinogenesis in exposed human populations which have identified useful biomarkers of exposure, effect and susceptibility for VC. These studies have in turn provided the basis for new molecular approaches for the prevention and treatment of VC cancers. This model could have much wider applicability for many other carcinogenic exposures and many other human cancers.

  12. Radiation carcinogenesis: radioprotectors and photosensitizers

    Energy Technology Data Exchange (ETDEWEB)

    Fry, R.J.M.

    1982-01-01

    This paper outlines 1) some of the salient features of radiation carcinogenesis that are pertinent to the questions of how the carcinogenic effects might be influenced, 2) the effects of radioprotectors on ionizing radiation-induced cancer, and 3) the effect of photosensitizers on UVR-induced skin cancer.

  13. Dose response problems in carcinogenesis.

    Science.gov (United States)

    Crump, K S

    1979-03-01

    The estimation of risks from exposure to carcinogens is an important problem from the viewpoint of protection of human health. It also poses some very difficult dose-response problems. Two dose-response models may fit experimental data about equally well and yet predict responses that differ by many orders of magnitude at low doses. Mechanisms of carcinogenesis are not sufficiently understood so that the shape of the dose-response curve at low doses can be satisfactorily predicted. Mathematical theories of carcinogenesis and statistical procedures can be of use with dose-reponse problems such as this and, in addition, can lead to a better understanding of the mechanisms of carcinogenesis. In this paper, mathematical dose-response models of carcinogenesis are considered as well as various proposed dose-response procedures for estimating carcinogenic risks at low doses. Areas are suggested in which further work may be useful. These areas include experimental design problems, statistical procedures for use with time-to-occurrence data, and mathematical models that incorporate such biological features as pharmacokinetics of carcinogens, synergistic effects, DNA repair, susceptible subpopulations, and immune reactions.

  14. DNA damage and carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Stelow, R B

    1980-01-01

    Although cancer may arise as a result of many different types of molecular changes, there is little reason to doubt that changes to DNA are one of the more important ones in cancer initiation. Although DNA repair mechanisms seem able to eliminate a very large fraction of deleterious changes to DNA, we not only have little insight into the molecular mechanisms involved in such repair, but have a negligible amount of information to permit us to estimate the shape of dose response relations at low doses. The case of skin cancer is a special one, in that the average population is exposed to sufficient solar uv so that the effects of small increments in uv dose may be estimated. An approximate 85% reduction in DNA repair increases skin cancer incidence 10/sup 4/ fold.

  15. Parasite Infection, Carcinogenesis and Human Malignancy

    Directory of Open Access Journals (Sweden)

    Hoang van Tong

    2017-02-01

    Full Text Available Cancer may be induced by many environmental and physiological conditions. Infections with viruses, bacteria and parasites have been recognized for years to be associated with human carcinogenicity. Here we review current concepts of carcinogenicity and its associations with parasitic infections. The helminth diseases schistosomiasis, opisthorchiasis, and clonorchiasis are highly carcinogenic while the protozoan Trypanosoma cruzi, the causing agent of Chagas disease, has a dual role in the development of cancer, including both carcinogenic and anticancer properties. Although malaria per se does not appear to be causative in carcinogenesis, it is strongly associated with the occurrence of endemic Burkitt lymphoma in areas holoendemic for malaria. The initiation of Plasmodium falciparum related endemic Burkitt lymphoma requires additional transforming events induced by the Epstein-Barr virus. Observations suggest that Strongyloides stercoralis may be a relevant co-factor in HTLV-1-related T cell lymphomas. This review provides an overview of the mechanisms of parasitic infection-induced carcinogenicity.

  16. Molecular piracy: the viral link to carcinogenesis.

    Science.gov (United States)

    Flaitz, C M; Hicks, M J

    1998-11-01

    The vast majority of the human experience with viral infections is associated with acute symptoms, such as malaise, fever, chills, rhinitis and diarrhea. With this acute or lytic phase, the immune system mounts a response and eliminates the viral agent while acquiring antibodies to that specific viral subtype. With latent or chronic infections, the viral agent becomes incorporated into the human genome. Viral agents capable of integration into the host's genetic material are particularly dangerous and may commandeer the host's ability to regulate normal cell growth and proliferation. The oncogenic viruses may immortalize the host cell, and facilitate malignant transformation. Cell growth and proliferation may be enhanced by viral interference with tumor suppressor gene function (p53 and pRb). Viruses may act as vectors for mutated proto-oncogenes (oncogenes). Overexpression of these oncogenes in viral-infected cells interferes with normal cell function and allows unregulated cell growth and proliferation, which may lead to malignant transformation and tumour formation. Development of oral neoplasms, both benign and malignant, has been linked to several viruses. Epstein-Barr virus is associated with oral hairy leukoplakia, lymphoproliferative disease, lymphoepithelial carcinoma, B-cell lymphomas, and nasopharyngeal carcinoma. Human herpesvirus-8 has been implicated in all forms of Kaposi's sarcoma, primary effusion lymphomas, multiple myeloma, angioimmunoblastic lymphadenopathy, and Castleman's disease. Human herpesvirus-6 has been detected in lymphoproliferative disease, lymphomas, Hodgkin's disease, and oral squamous cell carcinoma. The role of human papillomavirus in benign (squamous papilloma, focal epithelial hyperplasia, condyloma acuminatum, verruca vulgaris), premalignant (oral epithelial dysplasia), and malignant (squamous cell carcinoma) neoplasms within the oral cavity is well recognized. Herpes simplex virus may participate as a cofactor in oral squamous cell carcinoma development by enhancing activation, amplification, and overexpression of pre-existing oncogenes within neoplastic tissues. Because of the integral role of viruses in malignant transformation of host cells, innovative antiviral therapy may prevent tumour development, involute neoplastic proliferations, or arrest malignant progression.

  17. (Radiation carcinogenesis in the whole body system)

    Energy Technology Data Exchange (ETDEWEB)

    Fry, R.J.M.

    1990-12-14

    The objectives of the trip were: to take part in and to give the summary of a Symposium on Radiation Carcinogenesis at Tokyo, and to give a talk at the National Institute of Radiological Sciences at Chiba. The breadth of the aspects considered at the conference was about as broad as is possible, from effects at the molecular level to human epidemiology, from the effects of tritium to cancer induction by heavy ions. The events induced by cancer that lead to cancer and the events that are secondary are beginning to come into better focus but much is still not known. Interest in suppressor genes is increasing rapidly in the studies of human tumors and many would predict that the three or four suppressor genes associated with cancer are only the first sighting of a much larger number.

  18. Mathematical Modeling of Carcinogenesis Based on Chromosome Aberration Data

    Institute of Scientific and Technical Information of China (English)

    Xiao-bo Li

    2009-01-01

    Objective: The progression of human cancer is characterized by the accumulation of genetic instability. An increasing number of experimental genetic molecular techniques have been used to detect chromosome aberrations. Previous studies on chromosome abnormalities often focused on identifying the frequent loci of chromosome alterations, but rarely addressed the issue of interrelationship of chromosomal abnormalities. In the last few years, several mathematical models have been employed to construct models of carcinogenesis, in an attempt to identify the time order and cause-and-effect relationship of chromosome aberrations. The principles and applications of these models are reviewed and compared in this paper. Mathematical modeling of carcinogenesis can contribute to our understanding of the molecular genetics of tumor development, and identification of cancer related genes, thus leading to improved clinical practice of cancer.

  19. THE EVALUATION OF A TOOL FOR DISSEMINATION OF BIOTECHNOLOGY AND MOLECULAR BIOLOGY CONCEPTS IN FORMAL EDUCATION

    Directory of Open Access Journals (Sweden)

    F.M. Escanhoela

    2007-05-01

    Full Text Available Since 2003, the CBME Scientific Dissemination Coordination hasdeveloped a project related to the production and distribution of a scientificdissemination newspaper, called CBME InFORMAÇÃO, directed to high-schoolstudents and teachers. It is a quarterly publication and shows the concepts andadvances of studies in molecular biology and biotechnology. In order to evaluatethe newspaper, a research was accomplished in 2005. It involved 177 studentsfrom six high schools of São Carlos and region. In addition, opinions of fivescience teachers that worked with the newspaper in their classrooms, as well aseight Biology undergraduates were collected. The teachers received somequestionnaires that had to be answered by them and their students after a specifyactivity with the periodical – basically, the activities consisted of three stages:individual reading of the newspaper; formulation of questions by the teacher and,finally, group discussion on the chosen theme. The research confirmed theimportance of the use of the periodical as a tool in the formation of critical readersof facts related to the biotechnology and molecular biology, what should contributewith the citizenship development in the students. Moreover, it provided a possibilityto reorganize the periodical.

  20. A New Take on John Maynard Smith's Concept of Protein Space for Understanding Molecular Evolution.

    Science.gov (United States)

    Ogbunugafor, C Brandon; Hartl, Daniel L

    2016-10-01

    Much of the public lacks a proper understanding of Darwinian evolution, a problem that can be addressed with new learning and teaching approaches to be implemented both inside the classroom and in less formal settings. Few analogies have been as successful in communicating the basics of molecular evolution as John Maynard Smith's protein space analogy (1970), in which he compared protein evolution to the transition between the terms WORD and GENE, changing one letter at a time to yield a different, meaningful word (in his example, the preferred path was WORD → WORE → GORE → GONE → GENE). Using freely available computer science tools (Google Books Ngram Viewer), we offer an update to Maynard Smith's analogy and explain how it might be developed into an exploratory and pedagogical device for understanding the basics of molecular evolution and, more specifically, the adaptive landscape concept. We explain how the device works through several examples and provide resources that might facilitate its use in multiple settings, ranging from public engagement activities to formal instruction in evolution, population genetics, and computational biology.

  1. Preclinical Cancer Chemoprevention Studies Using Animal Model of Inflammation-Associated Colorectal Carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Takuji [Cytopatholgy Division, Tohkai Cytopathology Institute, Cancer Research and Prevention (TCI-CaRP), 5-1-2 Minami-uzura, Gifu 500-8285 (Japan); Department of Tumor Pathology, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194 (Japan)

    2012-07-16

    Inflammation is involved in all stages of carcinogenesis. Inflammatory bowel disease, such as ulcerative colitis and Crohn’s disease is a longstanding inflammatory disease of intestine with increased risk for colorectal cancer (CRC). Several molecular events involved in chronic inflammatory process are reported to contribute to multi-step carcinogenesis of CRC in the inflamed colon. They include over-production of free radicals, reactive oxygen and nitrogen species, up-regulation of inflammatory enzymes in arachidonic acid biosynthesis pathway, up-regulation of certain cytokines, and intestinal immune system dysfunction. In this article, firstly I briefly introduce our experimental animal models where colorectal neoplasms rapidly develop in the inflamed colorectum. Secondary, data on preclinical cancer chemoprevention studies of inflammation-associated colon carcinogenesis by morin, bezafibrate, and valproic acid, using this novel inflammation-related colorectal carcinogenesis model is described.

  2. Selenium in human mammary carcinogenesis

    DEFF Research Database (Denmark)

    Overvad, Kim; Grøn, P.; Langhoff, Otto;

    1991-01-01

    /l and TNM stage II 76 +/- 13 micrograms selenium/l), indicating disease-mediated changes. The evaluation of selenium as a risk indicator in human breast cancer was therefore restricted to TNM stage I patients (n = 36). Multiple logistic regression analyses including variables associated with selenium levels...... revealed no association between selenium levels and breast cancer risk.......In a case-referent study on the possible role of selenium in human mammary carcinogenesis, serum selenium was found to be 79 +/- 12 micrograms/l in 66 cases and 81 +/- 12 micrograms/l in 93 referents. An internal trend in serum selenium was observed among cases (TNM stage I 81 +/- 11 micrograms...

  3. Cyclooxygenase-2 and prostate carcinogenesis.

    Science.gov (United States)

    Hussain, Tajamul; Gupta, Sanjay; Mukhtar, Hasan

    2003-03-10

    In recent years a dramatic surge has occurred on studies defining to the role of cyclooxygenase (COX)-2 in causation and prevention of cancer. Prostaglandin (PG) endoperoxidase synthase also commonly referred to as COX is a key enzyme involved in the conversion of arachidonic acid to PGs and other eicosanoids. COX exists as two isoforms, namely COX-1 and COX-2 with distinct tissue distribution and physiological functions. COX-1 is constitutively expressed in many tissues and cell types and is involved in normal cellular physiological functions whereas COX-2 is pro-inflammatory in nature and is inducible by mitogens, cytokines, tumor promoters and growth factors. A large volume of data exists showing that COX-2 is overexpressed in a large number of human cancers and cancer cell lines. The possibility of COX-2 as a candidate player in cancer development and progression evolved from the epidemiological studies which suggest that regular use of aspirin or other non-steroidal anti-inflammatory drugs could significantly decrease the risk of developing cancers in experimental animals and in humans. In our recently published study (Prostate, 42 2000 73-78), we provided the first evidence that COX-2 is overexpressed in human prostate adenocarcinoma. Many other studies verified our initial observation and reported that compared to normal tissue, COX-2 is overexpressed in human prostate cancer. It should be noted that some recent work has suggested that COX-2 is only up-regulated in proliferative inflammatory atrophy of the prostate, but not in prostate carcinoma. In this scenario, COX-2 inhibitors could afford their effects against prostate carcinogenesis by modulating COX-2 activity in other cells in prostate. An exciting corollary to this ongoing work is that selective COX-2 inhibitors may exhibit chemopreventive and even chemotherapeutic effects against prostate carcinogenesis in humans.

  4. Midkine translocated to nucleoli and involved in carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    Li-Cheng Dai

    2009-01-01

    Midkine (MK) is a heparin-binding growth factor with its gene first identified in embryonal carcinoma cells at early stages of retinoic acid-induced differentiation.MK is frequently and highly expressed in a variety of human carcinomas. Furthermore, the blood MK level is frequently elevated with advance of human carcinomas, decreased after surgical removal of the tumors. Thus, it is expected to become a promising marker for evaluating the progress of carcinomas.There is mounting evidence that MK plays a significant role in carcinogenesis-related activities, such as proliferation, migration, anti-apoptosis, mitogenesis,transforming, and angiogenesis. In addition, siRNA and anti-sense oligonucleotides for MK have yielded great effects in anti-tumor activities. Therefore, MK appears to be a potential candidate molecular target of therapy for human carcinomas. In this paper, we review MK targeting at nucleoli in different tumor cells and its role in carcinogenesis to deepen our understanding of the mechanism of MK involved in carcinogenesis.

  5. Science literacy and meaningful learning: status of public high school students from Rio de Janeiro face to molecular biology concepts

    OpenAIRE

    Daniel Alves Escodino; Andréa Carla de Souza Góes

    2013-01-01

    In this work we aimed to determine the level of Molecular Biology (MB) science literacy of students from two Brazilian public schools which do not consider the rogerian theory for class planning and from another institution, Cap UERJ, which favours this theory. We applied semiclosed questionnaires specific to the different groups of science literacy levels. Besides, we have asked them to perform conceptual maps with MB concepts in order to observe if they have experienced meaningful learning....

  6. Emerging concepts in biomarker discovery; The US-Japan workshop on immunological molecular markers in oncology

    Directory of Open Access Journals (Sweden)

    Rivoltini Licia

    2009-06-01

    Full Text Available Abstract Supported by the Office of International Affairs, National Cancer Institute (NCI, the "US-Japan Workshop on Immunological Biomarkers in Oncology" was held in March 2009. The workshop was related to a task force launched by the International Society for the Biological Therapy of Cancer (iSBTc and the United States Food and Drug Administration (FDA to identify strategies for biomarker discovery and validation in the field of biotherapy. The effort will culminate on October 28th 2009 in the "iSBTc-FDA-NCI Workshop on Prognostic and Predictive Immunologic Biomarkers in Cancer", which will be held in Washington DC in association with the Annual Meeting. The purposes of the US-Japan workshop were a to discuss novel approaches to enhance the discovery of predictive and/or prognostic markers in cancer immunotherapy; b to define the state of the science in biomarker discovery and validation. The participation of Japanese and US scientists provided the opportunity to identify shared or discordant themes across the distinct immune genetic background and the diverse prevalence of disease between the two Nations. Converging concepts were identified: enhanced knowledge of interferon-related pathways was found to be central to the understanding of immune-mediated tissue-specific destruction (TSD of which tumor rejection is a representative facet. Although the expression of interferon-stimulated genes (ISGs likely mediates the inflammatory process leading to tumor rejection, it is insufficient by itself and the associated mechanisms need to be identified. It is likely that adaptive immune responses play a broader role in tumor rejection than those strictly related to their antigen-specificity; likely, their primary role is to trigger an acute and tissue-specific inflammatory response at the tumor site that leads to rejection upon recruitment of additional innate and adaptive immune mechanisms. Other candidate systemic and/or tissue-specific biomarkers

  7. Emerging concepts in biomarker discovery; the US-Japan Workshop on Immunological Molecular Markers in Oncology.

    Science.gov (United States)

    Tahara, Hideaki; Sato, Marimo; Thurin, Magdalena; Wang, Ena; Butterfield, Lisa H; Disis, Mary L; Fox, Bernard A; Lee, Peter P; Khleif, Samir N; Wigginton, Jon M; Ambs, Stefan; Akutsu, Yasunori; Chaussabel, Damien; Doki, Yuichiro; Eremin, Oleg; Fridman, Wolf Hervé; Hirohashi, Yoshihiko; Imai, Kohzoh; Jacobson, James; Jinushi, Masahisa; Kanamoto, Akira; Kashani-Sabet, Mohammed; Kato, Kazunori; Kawakami, Yutaka; Kirkwood, John M; Kleen, Thomas O; Lehmann, Paul V; Liotta, Lance; Lotze, Michael T; Maio, Michele; Malyguine, Anatoli; Masucci, Giuseppe; Matsubara, Hisahiro; Mayrand-Chung, Shawmarie; Nakamura, Kiminori; Nishikawa, Hiroyoshi; Palucka, A Karolina; Petricoin, Emanuel F; Pos, Zoltan; Ribas, Antoni; Rivoltini, Licia; Sato, Noriyuki; Shiku, Hiroshi; Slingluff, Craig L; Streicher, Howard; Stroncek, David F; Takeuchi, Hiroya; Toyota, Minoru; Wada, Hisashi; Wu, Xifeng; Wulfkuhle, Julia; Yaguchi, Tomonori; Zeskind, Benjamin; Zhao, Yingdong; Zocca, Mai-Britt; Marincola, Francesco M

    2009-06-17

    Supported by the Office of International Affairs, National Cancer Institute (NCI), the "US-Japan Workshop on Immunological Biomarkers in Oncology" was held in March 2009. The workshop was related to a task force launched by the International Society for the Biological Therapy of Cancer (iSBTc) and the United States Food and Drug Administration (FDA) to identify strategies for biomarker discovery and validation in the field of biotherapy. The effort will culminate on October 28th 2009 in the "iSBTc-FDA-NCI Workshop on Prognostic and Predictive Immunologic Biomarkers in Cancer", which will be held in Washington DC in association with the Annual Meeting. The purposes of the US-Japan workshop were a) to discuss novel approaches to enhance the discovery of predictive and/or prognostic markers in cancer immunotherapy; b) to define the state of the science in biomarker discovery and validation. The participation of Japanese and US scientists provided the opportunity to identify shared or discordant themes across the distinct immune genetic background and the diverse prevalence of disease between the two Nations. Converging concepts were identified: enhanced knowledge of interferon-related pathways was found to be central to the understanding of immune-mediated tissue-specific destruction (TSD) of which tumor rejection is a representative facet. Although the expression of interferon-stimulated genes (ISGs) likely mediates the inflammatory process leading to tumor rejection, it is insufficient by itself and the associated mechanisms need to be identified. It is likely that adaptive immune responses play a broader role in tumor rejection than those strictly related to their antigen-specificity; likely, their primary role is to trigger an acute and tissue-specific inflammatory response at the tumor site that leads to rejection upon recruitment of additional innate and adaptive immune mechanisms. Other candidate systemic and/or tissue-specific biomarkers were recognized that

  8. Receptor activator for nuclear factor-κB ligand signaling promotes progesterone-mediated estrogen-induced mammary carcinogenesis

    OpenAIRE

    Boopalan, Thiyagarajan; Arumugam, Arunkumar; Parada, Jacqueline; Saltzstein, Edward; Lakshmanaswamy, Rajkumar

    2015-01-01

    Breast cancer is a leading cause of cancer-related death in women. Prolonged exposure to the ovarian hormones estrogen and progesterone increases the risk of breast cancer. Although estrogen is known as a primary factor in mammary carcinogenesis, very few studies have investigated the role of progesterone. Receptor activator for nuclear factor-κB (NF-κB) ligand (RANKL) plays an important role in progesterone-induced mammary carcinogenesis. However, the molecular mechanism underlying RANKL-ind...

  9. Inhibition of carcinogenesis by tea.

    Science.gov (United States)

    Yang, Chung S; Maliakal, Pius; Meng, Xiaofeng

    2002-01-01

    Tea has received a great deal of attention because tea polyphenols are strong antioxidants, and tea preparations have inhibitory activity against tumorigenesis. The bioavailability and biotransformation of tea polyphenols, however, are key factors limiting these activities in vivo. The inhibition of tumorigenesis by green or black tea preparations has been demonstrated in animal models on different organ sites such as skin, lung, oral cavity, esophagus, forestomach, stomach, small intestine, colon, pancreas, and mammary gland. Epidemiological studies, however, have not yielded clear conclusions concerning the protective effects of tea consumption against cancer formation in humans. The discrepancy between the results from humans and animal models could be due to 1) the much higher doses of tea used in animals in comparison to human consumption, 2) the differences in causative factors between the cancers in humans and animals, and 3) confounding factors limiting the power of epidemiological studies to detect an effect. It is possible that tea may be only effective against specific types of cancer caused by certain etiological factors. Many mechanisms have been proposed for the inhibition of carcinogenesis by tea, including the modulation of signal transduction pathways that leads to the inhibition of cell proliferation and transformation, induction of apoptosis of preneoplastic and neoplastic cells, as well as inhibition of tumor invasion and angiogenesis. These mechanisms need to be evaluated and verified in animal models or humans in order to gain more understanding on the effect of tea consumption on human cancer.

  10. Instrumentation concepts and requirements for a space vacuum research facility. [molecular shield for spaceborne experiments

    Science.gov (United States)

    Norton, H. N.

    1979-01-01

    An earth-orbiting molecular shield that offers a unique opportunity for conducting physics, chemistry, and material processing experiments under a combination of environmental conditions that are not available in terrestrial laboratories is equipped with apparatus for forming a molecular beam from the freestream. Experiments are carried out using a moderate energy, high flux density, high purity atomic oxygen beam in the very low density environment within the molecular shield. As a minimum, the following instruments are required for the molecular shield: (1) a mass spectrometer; (2) a multifunction material analysis instrumentation system; and (3) optical spectrometry equipment. The design is given of a furlable molecular shield that allows deployment and retrieval of the system (including instrumentation and experiments) to be performed without contamination. Interfaces between the molecular shield system and the associated spacecraft are given. An in-flight deployment sequence is discussed that minimizes the spacecraft-induced contamination in the vicinity of the shield. Design approaches toward a precursor molecular shield system are shown.

  11. Clinical and molecular analyses of Beckwith-Wiedemann syndrome: Comparison between spontaneous conception and assisted reproduction techniques.

    Science.gov (United States)

    Tenorio, Jair; Romanelli, Valeria; Martin-Trujillo, Alex; Fernández, García-Moya; Segovia, Mabel; Perandones, Claudia; Pérez Jurado, Luis A; Esteller, Manel; Fraga, Mario; Arias, Pedro; Gordo, Gema; Dapía, Irene; Mena, Rocío; Palomares, María; Pérez de Nanclares, Guiomar; Nevado, Julián; García-Miñaur, Sixto; Santos-Simarro, Fernando; Martinez-Glez, Víctor; Vallespín, Elena; Monk, David; Lapunzina, Pablo

    2016-10-01

    Beckwith-Wiedemann syndrome (BWS) is an overgrowth syndrome characterized by an excessive prenatal and postnatal growth, macrosomia, macroglossia, and hemihyperplasia. The molecular basis of this syndrome is complex and heterogeneous, involving genes located at 11p15.5. BWS is correlated with assisted reproductive techniques. BWS in individuals born following assisted reproductive techniques has been found to occur four to nine times higher compared to children with to BWS born after spontaneous conception. Here, we report a series of 187 patients with to BWS born either after assisted reproductive techniques or conceived naturally. Eighty-eight percent of BWS patients born via assisted reproductive techniques had hypomethylation of KCNQ1OT1:TSS-DMR in comparison with 49% for patients with BWS conceived naturally. None of the patients with BWS born via assisted reproductive techniques had hypermethylation of H19/IGF2:IG-DMR, neither CDKN1 C mutations nor patUPD11. We did not find differences in the frequency of multi-locus imprinting disturbances between groups. Patients with BWS born via assisted reproductive techniques had an increased frequency of advanced bone age, congenital heart disease, and decreased frequency of earlobe anomalies but these differences may be explained by the different molecular background compared to those with BWS and spontaneous fertilization. We conclude there is a correlation of the molecular etiology of BWS with the type of conception. © 2016 Wiley Periodicals, Inc.

  12. Taxonomic identification of algae (morphological and molecular): species concepts, methodologies, and their implications for ecological bioassessment.

    Science.gov (United States)

    Manoylov, Kalina M

    2014-06-01

    Algal taxonomy is a key discipline in phycology and is critical for algal genetics, physiology, ecology, applied phycology, and particularly bioassessment. Taxonomic identification is the most common analysis and hypothesis-testing endeavor in science. Errors of identification are often related to the inherent problem of small organisms with morphologies that are difficult to distinguish without research-grade microscopes and taxonomic expertise in phycology. Proposed molecular approaches for taxonomic identification from environmental samples promise rapid, potentially inexpensive, and more thorough culture-independent identification of all algal species present in a sample of interest. Molecular identification has been used in biodiversity and conservation, but it also has great potential for applications in bioassessment. Comparisons of morphological and molecular identification of benthic algal communities are improved by the identification of more taxa; however, automated identification technology does not allow for the simultaneous analysis of thousands of samples. Currently, morphological identification is used to verify molecular taxonomic identities, but with the increased number of taxa verified in algal gene libraries, molecular identification will become a universal tool in biological studies. Thus, in this report, successful application of molecular techniques related to algal bioassessment is discussed.

  13. [Monoamines stimulations in experimental carcinogenesis].

    Science.gov (United States)

    Popov, I; Spuzić, I; Rakić, Lj

    1994-01-01

    Facts about the role of CNS monoamines in cancerogenesis have been accumulated for many years. The aim of the present study was to investigate the effect of interaction of psychoactive drug (Piracetam) and other treatments on survival time of tumour-bearing rats. 138 Wistar rats were used in the experiment. The animals were injected 1% 3--Methilcholantren suspension in 10% Tylose, s.c. under the dorsal skin of the neck in a dose of 3 mg/animal. Within 4-9 months after a single injection, the rats developed tumours at the site of injection. The surgical removal was performed when tumours reached the size of 1-3 cm. After surgical extirpation of tumours different groups of animals were treated by cyclophosphamide (s.c. one-time dose of 50 mg/kg for female and 100 mg/kg for male) or by psychoactive drug (Piracetam) administrated by GE tube 5 time/week, 100 mg/kg. Autopsy and histological examinations were carried out in all animals. Survival time (> 120 days) was the greatest in group B (Piracetam, after surgical removal of tumours) 81.2%, and group C (Cyclophosphamid, after surgical removal of tumours) 68.8% and in group A (only surgical removal of tumours) 50%. In group B the incidence of metastases was the smallest (87.1% of animals were without metastases), compared with group C (45.4% of animals were without metastases) and group A (27.3% of animals were without metastases). The diference is statistically significant. The mechanism of antineoplastic effect of Piracetam consisted of the interaction of influences both on metabolism of the Central nervous system and the tumour. Probably, it is the neurotransmitter modulation that had its effect on carcinogenesis not only by regulation/disregulation of brain homeostasis, but also via direct effect on intracellular processes during cell development and differentation.

  14. Molecular biology of mycoplasmas: from the minimum cell concept to the artificial cell

    Directory of Open Access Journals (Sweden)

    CAIO M.M. CORDOVA

    2016-01-01

    Full Text Available ABSTRACT Mycoplasmas are a large group of bacteria, sorted into different genera in the Mollicutes class, whose main characteristic in common, besides the small genome, is the absence of cell wall. They are considered cellular and molecular biology study models. We present an updated review of the molecular biology of these model microorganisms and the development of replicative vectors for the transformation of mycoplasmas. Synthetic biology studies inspired by these pioneering works became possible and won the attention of the mainstream media. For the first time, an artificial genome was synthesized (a minimal genome produced from consensus sequences obtained from mycoplasmas. For the first time, a functional artificial cell has been constructed by introducing a genome completely synthesized within a cell envelope of a mycoplasma obtained by transformation techniques. Therefore, this article offers an updated insight to the state of the art of these peculiar organisms' molecular biology.

  15. Molecular biology of mycoplasmas: from the minimum cell concept to the artificial cell.

    Science.gov (United States)

    Cordova, Caio M M; Hoeltgebaum, Daniela L; Machado, Laís D P N; Santos, Larissa Dos

    2016-01-01

    Mycoplasmas are a large group of bacteria, sorted into different genera in the Mollicutes class, whose main characteristic in common, besides the small genome, is the absence of cell wall. They are considered cellular and molecular biology study models. We present an updated review of the molecular biology of these model microorganisms and the development of replicative vectors for the transformation of mycoplasmas. Synthetic biology studies inspired by these pioneering works became possible and won the attention of the mainstream media. For the first time, an artificial genome was synthesized (a minimal genome produced from consensus sequences obtained from mycoplasmas). For the first time, a functional artificial cell has been constructed by introducing a genome completely synthesized within a cell envelope of a mycoplasma obtained by transformation techniques. Therefore, this article offers an updated insight to the state of the art of these peculiar organisms' molecular biology.

  16. What gastric cancer proteomic studies show about gastric carcinogenesis?

    Science.gov (United States)

    Leal, Mariana Ferreira; Wisnieski, Fernanda; de Oliveira Gigek, Carolina; do Santos, Leonardo Caires; Calcagno, Danielle Queiroz; Burbano, Rommel Rodriguez; Smith, Marilia Cardoso

    2016-08-01

    Gastric cancer is a complex, heterogeneous, and multistep disease. Over the past decades, several studies have aimed to determine the molecular factors that lead to gastric cancer development and progression. After completing the human genome sequencing, proteomic technologies have presented rapid progress. Differently from the relative static state of genome, the cell proteome is dynamic and changes in pathologic conditions. Proteomic approaches have been used to determine proteome profiles and identify differentially expressed proteins between groups of samples, such as neoplastic and nonneoplastic samples or between samples of different cancer subtypes or stages. Therefore, proteomic technologies are a useful tool toward improving the knowledge of gastric cancer molecular pathogenesis and the understanding of tumor heterogeneity. This review aimed to summarize the proteins or protein families that are frequently identified by using high-throughput screening methods and which thus may have a key role in gastric carcinogenesis. The increased knowledge of gastric carcinogenesis will clearly help in the development of new anticancer treatments. Although the studies are still in their infancy, the reviewed proteins may be useful for gastric cancer diagnosis, prognosis, and patient management.

  17. Improved Student Linkage of Mendelian and Molecular Genetic Concepts through a Yeast-Based Laboratory Module

    Science.gov (United States)

    Wolyniak, Michael J.

    2013-01-01

    A study of modern genetics requires students to successfully unite the principles of Mendelian genetics with the functions of DNA. Traditional means of teaching genetics are often successful in teaching Mendelian and molecular ideas but not in allowing students to see how the two subjects relate. The laboratory module presented here attempts to…

  18. 11β-羟基类固醇脱氢酶2基因表达作为葡萄籽提取物预防乳腺癌靶点的探讨%Expression of 11 beta-hydroxysteroid dehydrogenase type 2 genes as a molecular target endpoint for the prevention of breast cell carcinogenesis with grape seed extracts

    Institute of Scientific and Technical Information of China (English)

    宋筱瑜; 王华骞

    2011-01-01

    Objective To study the change of 11 β-HSD 2 gene expression in carcinogenesis and cancer prevention and to study the possibility of using 11 β-HSD 2 gene expression as a molecular target endpoint in the progression of breast cell carcinogenesis suppressed by Grape Seed Extract (GSE). Methods Cell carcinogenesis model for human breast epithelial MCF10A cell was induced by treating the cell with carcinogens NNK and B[ a] P repeatedly, and the cell model system for the prevention of carcinogenesis was developed by combining GSE with NNK and B[ a] P. Western blot analysis was used to detect the expression of 11 β-HSD 2 gene. The biological change of carcinogen treated cells was studied by transfecting small interference RNA ( siRNA ) to inhibit 11 β-HSD 2 gene expression of cells. Results The colony formation of carcinogen treated cells in low-mitogen medium was less after the expression of 11 β-HSD 2 gene was inhibited by specific siRNA, which was just like the colony formation of normal cells. The expression of 11 β-HSD 2 gene was high in carcinogen treated cells, and the gene expression was low or undetectable in normal breast epithelial cells and cells combined treated with GSE and carcinogen. Conclusion The biological display of carcinogen treated cells could be normalized after the expression of 11 β-HSD 2 gene was inhibited. The mechanism for GSE preventing carcinogenesis might be the result of GSE inhibiting the expression of 11β-HSD 2 gene. 11β-HSD 2 gene might be the molecular target endpoint for the suppression of breast cell carcinogenesis by GSE.%目的 研究11β-羟基类固醇脱氢酶2型基因(11β-HSD 2)表达在癌症发生及预防过程中的变化,探讨该基因作为葡萄籽提取物(GSE)抑制乳腺上皮细胞慢性癌变过程中靶点的可能性.方法 建立低浓度致癌物NNK和B[a]P刺激乳腺上皮细胞MCF 10A癌变及GSE抑制乳腺上皮细胞癌变过程的细胞模型,研究瞬时转染了靶向11β-HSD 2基因的

  19. Electron ionization LC-MS with supersonic molecular beams--the new concept, benefits and applications.

    Science.gov (United States)

    Seemann, Boaz; Alon, Tal; Tsizin, Svetlana; Fialkov, Alexander B; Amirav, Aviv

    2015-11-01

    A new type of electron ionization LC-MS with supersonic molecular beams (EI-LC-MS with SMB) is described. This system and its operational methods are based on pneumatic spray formation of the LC liquid flow in a heated spray vaporization chamber, full sample thermal vaporization and subsequent electron ionization of vibrationally cold molecules in supersonic molecular beams. The vaporized sample compounds are transferred into a supersonic nozzle via a flow restrictor capillary. Consequently, while the pneumatic spray is formed and vaporized at above atmospheric pressure the supersonic nozzle backing pressure is about 0.15 Bar for the formation of supersonic molecular beams with vibrationally cold sample molecules without cluster formation with the solvent vapor. The sample compounds are ionized in a fly-though EI ion source as vibrationally cold molecules in the SMB, resulting in 'Cold EI' (EI of vibrationally cold molecules) mass spectra that exhibit the standard EI fragments combined with enhanced molecular ions. We evaluated the EI-LC-MS with SMB system and demonstrated its effectiveness in NIST library sample identification which is complemented with the availability of enhanced molecular ions. The EI-LC-MS with SMB system is characterized by linear response of five orders of magnitude and uniform compound independent response including for non-polar compounds. This feature improves sample quantitation that can be approximated without compound specific calibration. Cold EI, like EI, is free from ion suppression and/or enhancement effects (that plague ESI and/or APCI) which facilitate faster LC separation because full separation is not essential. The absence of ion suppression effects enables the exploration of fast flow injection MS-MS as an alternative to lengthy LC-MS analysis. These features are demonstrated in a few examples, and the analysis of the main ingredients of Cannabis on a few Cannabis flower extracts is demonstrated. Finally, the advantages of

  20. Science literacy and meaningful learning: status of public high school students from Rio de Janeiro face to molecular biology concepts

    Directory of Open Access Journals (Sweden)

    Daniel Alves Escodino

    2013-12-01

    Full Text Available In this work we aimed to determine the level of Molecular Biology (MB science literacy of students from two Brazilian public schools which do not consider the rogerian theory for class planning and from another institution, Cap UERJ, which favours this theory. We applied semiclosed questionnaires specific to the different groups of science literacy levels. Besides, we have asked them to perform conceptual maps with MB concepts in order to observe if they have experienced meaningful learning. Finally, we prepared MB classes for students of the three schools, considering their conceptual maps and tried to evaluate, through a second map execution, if the use of alternative didactics material, which consider meaningful learning process, would have any effect over the appropriation of new concepts. We observed that most students are placed at Functional literacy level. Nonetheless, several students from CAp were also settled at the higher Conceptual and Procedural levels. We found that most students have not experienced meaningful learning and that the employment of didactic material and implementation of proposals which consider the cognitive structure of the students had a significant effect on the appropriation of several concepts.

  1. History, Classification, Molecular Structure and Properties of Dendrimers which are a New Concept in Textile

    Directory of Open Access Journals (Sweden)

    Osman NAMIRTI

    2011-02-01

    Full Text Available Over the last 20 years polymer chemistry has created a number of non-lineer structures and introduction of a large number of branches during the polymer synthesis leads to obtain molecules with many end groups. Two types of these polymers are regularly branched "dendrimers" and "hyperbranched polymers" where branching is formed randomly. In this article knowledge about history, classification, molecular structure and properties of dendrimers which have found various application areas also in textile due to their special structures is given.

  2. Tumour biology of obesity-related cancers: understanding the molecular concept for better diagnosis and treatment.

    Science.gov (United States)

    Teoh, Seong Lin; Das, Srijit

    2016-11-01

    Obesity continues to be a major global problem. Various cancers are related to obesity and proper understanding of their aetiology, especially their molecular tumour biology is important for early diagnosis and better treatment. Genes play an important role in the development of obesity. Few genes such as leptin, leptin receptor encoded by the db (diabetes), pro-opiomelanocortin, AgRP and NPY and melanocortin-4 receptors and insulin-induced gene 2 were linked to obesity. MicroRNAs control gene expression via mRNA degradation and protein translation inhibition and influence cell differentiation, cell growth and cell death. Overexpression of miR-143 inhibits tumour growth by suppressing B cell lymphoma 2, extracellular signal-regulated kinase-5 activities and KRAS oncogene. Cancers of the breast, uterus, renal, thyroid and liver are also related to obesity. Any disturbance in the production of sex hormones and insulin, leads to distortion in the balance between cell proliferation, differentiation and apoptosis. The possible mechanism linking obesity to cancer involves alteration in the level of adipokines and sex hormones. These mediators act as biomarkers for cancer progression and act as targets for cancer therapy and prevention. Interestingly, many anti-cancerous drugs are also beneficial in treating obesity and vice versa. We also reviewed the possible link in the mechanism of few drugs which act both on cancer and obesity. The present review may be important for molecular biologists, oncologists and clinicians treating cancers and also pave the way for better therapeutic options.

  3. Craniofacial development: current concepts in the molecular basis of Treacher Collins syndrome.

    Science.gov (United States)

    van Gijn, Daniel Richard; Tucker, Abigail S; Cobourne, Martyn T

    2013-07-01

    The human face and skull are an elegant example of the anatomical sophistication that results from the interplay between the molecular cascades and the tissue interactions that are necessary for the proper development of the craniofacial complex. When it fails to develop normally the consequences can have life-long implications for the biological, psychological, and aesthetic wellbeing of an affected person. Among the many syndromes that affect the region, understanding of the biology that underlies Treacher Collins syndrome has advanced in the last decade, particularly concerning the causative TCOF1 gene that encodes TREACLE protein, a serine/alanine-rich nucleolar phosphoprotein with an essential function during ribosome biogenesis in cranial neural crest cells. Abnormal growth and differentiation of these cells affect much of the craniofacial skeleton.

  4. Sirt3, Mitochondrial ROS, Ageing, and Carcinogenesis

    Directory of Open Access Journals (Sweden)

    David Gius

    2011-09-01

    Full Text Available One fundamental observation in cancer etiology is that the rate of malignancies in any mammalian population increases exponentially as a function of age, suggesting a mechanistic link between the cellular processes governing longevity and carcinogenesis. In addition, it is well established that aberrations in mitochondrial metabolism, as measured by increased reactive oxygen species (ROS, are observed in both aging and cancer. In this regard, genes that impact upon longevity have recently been characterized in S. cerevisiae and C. elegans, and the human homologs include the Sirtuin family of protein deacetylases. Interestingly, three of the seven sirtuin proteins are localized into the mitochondria suggesting a connection between the mitochondrial sirtuins, the free radical theory of aging, and carcinogenesis. Based on these results it has been hypothesized that Sirt3 functions as a mitochondrial fidelity protein whose function governs both aging and carcinogenesis by modulating ROS metabolism. Sirt3 has also now been identified as a genomically expressed, mitochondrial localized tumor suppressor and this review will outline potential relationships between mitochondrial ROS/superoxide levels, aging, and cell phenotypes permissive for estrogen and progesterone receptor positive breast carcinogenesis.

  5. Experimental radiation carcinogenesis: what have we learned

    Energy Technology Data Exchange (ETDEWEB)

    Fry, R.J.M.

    1980-01-01

    The author reviews the need for animal experiments in development of a biological model for radioinduced carcinogenesis. He concludes they are vital for: (1) study of mechanisms; (2) establishment of generalizations; (3) elucidation of dose-response and time-dose relationships; and (4) determination of dose-distributions and their results, particularly for radionuclides. (PSB)

  6. A Critical Analysis of Rejection in Vascularized Composite Allotransplantation: Clinical, cellular and molecular aspects, Current Challenges, and Novel Concepts

    Directory of Open Access Journals (Sweden)

    Karim A Sarhane

    2013-11-01

    Full Text Available Advances in microsurgical techniques and immunomodulatory protocols have contributed to the expansion of Vascularized Composite Allotransplantation (VCA with very encouraging immunological, functional, and cosmetic results. Rejection remains however a major hurdle that portends serious threats to recipients. Rejection features in VCA have been described in a number of studies, and an international consensus on the classification of rejection was established. Unfortunately, current available diagnostic methods carry many shortcomings that, in certain cases, pose a great diagnostic challenge to physicians especially in borderline rejection cases. In this review, we revisit the features of acute skin rejection in hand and face transplantation at the clinical, cellular and molecular levels. The multiple challenges in diagnosing rejection and in defining chronic and antibody-mediated rejection in VCA are then presented, and we finish by analyzing current research directions and novel concepts aiming at improving available diagnostic measures.

  7. The geometric phase in quantum systems foundations, mathematical concepts, and applications in molecular and condensed matter physics

    CERN Document Server

    Böhm, Arno; Koizumi, Hiroyasu; Niu, Qian; Zwanziger, Joseph

    2003-01-01

    Aimed at graduate physics and chemistry students, this is the first comprehensive monograph covering the concept of the geometric phase in quantum physics from its mathematical foundations to its physical applications and experimental manifestations It contains all the premises of the adiabatic Berry phase as well as the exact Anandan-Aharonov phase It discusses quantum systems in a classical time-independent environment (time dependent Hamiltonians) and quantum systems in a changing environment (gauge theory of molecular physics) The mathematical methods used are a combination of differential geometry and the theory of linear operators in Hilbert Space As a result, the monograph demonstrates how non-trivial gauge theories naturally arise and how the consequences can be experimentally observed Readers benefit by gaining a deep understanding of the long-ignored gauge theoretic effects of quantum mechanics and how to measure them

  8. New bioproduction systems: from molecular circuits to novel reactor concepts in cell-free biotechnology.

    Science.gov (United States)

    Rupp, Steffen

    2013-01-01

    : The last decades witnessed a strong growth in several areas of biotechnology, especially in fields related to health, as well as in industrial biotechnology. Advances in molecular engineering now enable biotechnologists to design more efficient pathways in order to convert a larger spectrum of renewable resources into industrially used biofuels and chemicals as well as into new pharmaceuticals and therapeutic proteins. In addition material sciences advanced significantly making it more and more possible to integrate biology and engineering. One of the key questions currently is how to develop new ways of engineering biological systems to cope with the complexity and limitations given by the cell. The options to integrate biology with classical engineering advanced cell free technologies in the recent years significantly. Cell free protein production using cellular extracts is now a well-established universal technology for production of proteins derived from many organisms even at the milligram scale. Among other applications it has the potential to supply the demand for a multitude of enzymes and enzyme variants facilitating in vitro metabolic engineering. This review will briefly address the recent achievements and limitations of cell free conversions. Especially, the requirements for reactor systems in cell free biotechnology, a currently underdeveloped field, are reviewed and some perspectives are given on how material sciences and biotechnology might be able to advance these new developments in the future.

  9. Concepts and Molecular Aspects in the Polypharmacology of PARP-1 Inhibitors.

    Science.gov (United States)

    Passeri, Daniela; Camaioni, Emidio; Liscio, Paride; Sabbatini, Paola; Ferri, Martina; Carotti, Andrea; Giacchè, Nicola; Pellicciari, Roberto; Gioiello, Antimo; Macchiarulo, Antonio

    2016-06-20

    Recent years have witnessed a renewed interest in PARP-1 inhibitors as promising anticancer agents with multifaceted functions. Particularly exciting developments include the approval of olaparib (Lynparza) for the treatment of refractory ovarian cancer in patients with BRCA1/2 mutations, and the increasing understanding of the polypharmacology of PARP-1 inhibitors. The aim of this review article is to provide the reader with a comprehensive overview of the distinct levels of the polypharmacology of PARP-1 inhibitors, including 1) inter-family polypharmacology, 2) intra-family polypharmacology, and 3) multi-signaling polypharmacology. Progress made in gaining insight into the molecular basis of these multiple target-independent and target-dependent activities of PARP-1 inhibitors are discussed, with an outlook on the potential impact that a better understanding of polypharmacology may have in aiding the explanation as to why some drug candidates work better than others in clinical settings, albeit acting on the same target with similar inhibitory potency.

  10. Collimator design for a dedicated molecular breast imaging-guided biopsy system: Proof-of-concept

    Energy Technology Data Exchange (ETDEWEB)

    Weinmann, Amanda L.; Hruska, Carrie B.; Conners, Amy L.; O' Connor, Michael K. [Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905 (United States)

    2013-01-15

    Purpose: Molecular breast imaging (MBI) is a dedicated nuclear medicine breast imaging modality that employs dual-head cadmium zinc telluride (CZT) gamma cameras to functionally detect breast cancer. MBI has been shown to detect breast cancers otherwise occult on mammography and ultrasound. Currently, a MBI-guided biopsy system does not exist to biopsy such lesions. Our objective was to consider the utility of a novel conical slant-hole (CSH) collimator for rapid (<1 min) and accurate monitoring of lesion position to serve as part of a MBI-guided biopsy system. Methods: An initial CSH collimator design was derived from the dimensions of a parallel-hole collimator optimized for MBI performed with dual-head CZT gamma cameras. The parameters of the CSH collimator included the collimator height, cone slant angle, thickness of septa and cones of the collimator, and the annular areas exposed at the base of the cones. These parameters were varied within the geometric constraints of the MBI system to create several potential CSH collimator designs. The CSH collimator designs were evaluated using Monte Carlo simulations. The model included a breast compressed to a thickness of 6 cm with a 1-cm diameter lesion located 3 cm from the collimator face. The number of particles simulated was chosen to represent the count density of a low-dose, screening MBI study acquired with the parallel-hole collimator for 10 min after a {approx}150 MBq (4 mCi) injection of Tc-99m sestamibi. The same number of particles was used for the CSH collimator simulations. In the resulting simulated images, the count sensitivity, spatial resolution, and accuracy of the lesion depth determined from the lesion profile width were evaluated. Results: The CSH collimator design with default parameters derived from the optimal parallel-hole collimator provided 1-min images with error in the lesion depth estimation of 1.1 {+-} 0.7 mm and over 21 times the lesion count sensitivity relative to 1-min images

  11. Pathogenesis and biomarkers of carcinogenesis in ulcerative colitis

    DEFF Research Database (Denmark)

    Thorsteinsdottir, Sigrun; Gudjonsson, Thorkell; Nielsen, Ole Haagen;

    2011-01-01

    One of the most serious complications of ulcerative colitis is the development of colorectal cancer. Screening patients with ulcerative colitis by standard histological examination of random intestinal biopsy samples might be inefficient as a method of cancer surveillance. This Review focuses......-driven mechanisms of DNA damage, including the generation and effects of reactive oxygen species, microsatellite instability, telomere shortening and chromosomal instability, are reviewed, as are the molecular responses to genomic stress. We also discuss how these mechanisms can be translated into usable biomarkers....... Although progress has been made in the understanding of inflammation-driven carcinogenesis, markers based on these findings possess insufficient sensitivity or specificity to be usable as reliable biomarkers for risk of colorectal cancer development in patients with ulcerative colitis. However, screening...

  12. [The role of sonic hedgehog pathway in skin carcinogenesis].

    Science.gov (United States)

    Lesiak, Aleksandra; Sysa-Jedrzejowska, Anna; Narbutt, Joanna

    2010-08-01

    Non melanoma skin cancers (NMSC) involving basal (BCC)--and squamosus cell carcinomas (SCC) and are the most frequent skin cancers in Caucasians. Ultraviolet radiation is the main environmental risk factor for NMSC development. The aim of this paper is to review the latest opinions concerning the role of sonic hedgehog pathway in non-melanoma skin cancers development. Experimental data indicate that sonic hedgehog pathway might be involved in skin carcinogenesis. Under physiological conditions sonic hedgehog pathway is responsible for normal embryogenesis, regeneration of damaged tissues and for regulation of cell proliferation. It was revealed that UVR caused inactivated mutation in PATCHED gene encoding Ptch1 protein. These events lead to deregulation of sonic hedgehog pathway trough activation of Smo protein and Gli transcriptional factors what stimulates cell proliferation and in consequence NMSC development. Literature data indicate that understanding of molecular background of skin cancers might be a reason for introduction of new therapeutic approaches including sonic hedgehog pathway inhibitors.

  13. Multi-step pancreatic carcinogenesis and its clinical implications.

    Science.gov (United States)

    Sakorafas, G H; Tsiotou, A G

    1999-12-01

    The poor prognosis of pancreatic cancer relates mainly to its delayed diagnosis. It has been repeatedly shown that earlier diagnosis of pancreatic cancer is associated with a better outcome. Molecular diagnostic methods (mainly detection of K-ras mutations in pure pancreatic or duodenal juice, on specimens obtained by percutaneous fine-needle aspirations or in stool specimens) can achieve earlier diagnosis in selected subgroups of patients, such as patients with chronic pancreatitis (especially hereditary), adults with recent onset of non-insulin-dependent diabetes mellitus and patients with some inherited disorders that predispose to the development of pancreatic cancer. There is increasing evidence that pancreatic carcinogenesis is a multi-step phenomenon. Screening procedures for precursor lesions in these selected subgroups of patients may reduce the incidence and mortality from pancreatic cancer.

  14. Mechanisms of carcinogenesis in human skin against the background of papillomavirus infection.

    Science.gov (United States)

    Reva, I V; Reva, G V; Yamamoto, T; Tolmachyov, V E

    2014-09-01

    The cells in the skin tumor developing under conditions of persisting papillomavirus infection are morphologically identical to blast cells in a blood smear from a leukemia patient. The cells filling the lesion focus are morphologically and immunohistochemically related to blood stem cells. A mechanism of epithelial layer modification under conditions of papillomavirus infection leading to carcinogenesis is proposed. The dynamics of structural changes in the skin is characterized by disturbed interactions between the epithelium and adjacent connective tissue, destruction of the basal membrane, disorders in the cambial keratinocyte differentiation, and absence of the spinous and granular layers. We conclude that detection of blast leukocytes in the human skin lesion can be explained by disorders in the cell-cell interactions in the epithelium-mesenchymal tissue system. High proliferative activity followed by death of cambial keratinocytes, migration of effector antigen-presenting CD68 cells to the adjacent connective tissue are the factors inducing migration of blast leukocytic forms to the focus. Not only keratinocyte restitution capacity, but also epithelium-dependent differentiation of young leukocytes disappeared. Undifferentiated cells are migrated from the blood to the epithelium alteration zone, but not in the reverse direction. The insufficiency or the absence of blood blast cell differentiation of the in the focus of epidermal injury and adjacent tissue triggers carcinogenesis. The authors suggest their model of carcinogenesis. The conclusions offer a new concept of cancer pathogenesis and suggest a new strategy in the search for methods for early diagnosis of carcinogenesis.

  15. Study of chemical and radiation induced carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Chmura, A.

    1995-11-01

    The study of chemical and radiation induced carcinogenesis has up to now based many of its results on the detection of genetic aberrations using the fluorescent in situ hybridization (FISH) technique. FISH is time consuming and this tends to hinder its use for looking at large numbers of samples. We are currently developing new technological advances which will increase the speed, clarity and functionality of the FISH technique. These advances include multi-labeled probes, amplification techniques, and separation techniques.

  16. Inhibition of carcinogenesis by retinoids. [Review

    Energy Technology Data Exchange (ETDEWEB)

    Nettesheim, P.

    1979-01-01

    Progress made in recent years in the search for retinoids with anticarcinogenic activity is reviewed. There are many studies to be found in the literature which show no substantial effect of retinoids on carcinogenesis or tumor growth. Some of these negative findings may be related to the carcinogen dose used, the type of retinoid used, the dose, dose schedule or mode of administration of the retinoid. Others may indicate that the particular type of tumor or tumor system is, indeed, refractory to retinoids in general or to those retinoids that were tested. A great gap still exists in our knowledge concerning the pharmake-kinetics of most retinoids their availability to various normal and cancerous tissues, and the role and existence of transport and binding proteins. There are studies which indicate that under certain conditions, particularly conditions of topical application, some retinoids may even enhance carcinogenesis. It seems, however, indisputable by now that some retinoids are effective inhibitors of carcinogenesis in some organ systems and can even inhibit the growth of some established tumors. While the mechanisms of these inhibitory effects are presently not understood, it does seem clear that they are not mediated via the cytotoxic mechanisms typical of chemotherapeutic agents. The hope that retinoids might become an effective tool to halt the progression of some neoplastic diseases, seems to be justified.

  17. Actin Immobilization on Chitin for Purifying Myosin II: A Laboratory Exercise That Integrates Concepts of Molecular Cell Biology and Protein Chemistry

    Science.gov (United States)

    de Souza, Marcelle Gomes; Grossi, Andre Luiz; Pereira, Elisangela Lima Bastos; da Cruz, Carolina Oliveira; Mendes, Fernanda Machado; Cameron, Luiz Claudio; Paiva, Carmen Lucia Antao

    2008-01-01

    This article presents our experience on teaching biochemical sciences through an innovative approach that integrates concepts of molecular cell biology and protein chemistry. This original laboratory exercise is based on the preparation of an affinity chromatography column containing F-actin molecules immobilized on chitin particles for purifying…

  18. Mechanisms of carcinogenesis prevention by flavonoids

    Directory of Open Access Journals (Sweden)

    G. A. Belitsky

    2014-01-01

    Full Text Available The mechanisms of anticancerogenic effects of flavanoids and isocyanates from the plants widely consumed in the midland belt of Russia were reviewed. Data of studies both in vitro and in vivo were analyzed. Special attention was paid to inhibition of targets responsible for carcinogen metabolic activation, carcinogenesis promotion and tumor progression as well as neoangiogenesis. Besides that the antioxidant properties of flavonoids and their effects on cell cycle regulation, apoptosis initiation and cell mobility were considered.

  19. Detouring the Undesired Route of Helicobacter pylori-Induced Gastric Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Ki Baik Hahm

    2011-07-01

    Full Text Available Epidemiological and experimental evidence has emerged that a dysregulated inflammation is associated with most of the tumors, and many studies have begun to unravel the molecular pathways linking inflammation and cancer. As a typical example linking these associations, Helicobacter pylori (H. pylori infection-associated atrophic gastritis has been recognized as precursor lesion of gastric cancer. The identification of transcription factors such as NF-κB and STAT3, and their gene products such as IL-8, COX-2, iNOS, cytokines, chemokines and their receptors, etc have laid the molecular foundation for our understanding of the decisive role of inflammation in carcinogenesis. In addition to the role as the initiator of cancer, inflammation contributes to survival and proliferation of malignant cells, tumor angiogenesis, and even metastasis. In this review, the fundamental mechanisms of H. pylori-induced carcinogenesis as well as the possibility of cancer prevention through suppressing H. pylori-induced inflammation are introduced. We infer that targeting inflammatory pathways have a potential role to detour the unpleasant journey to H. pylori-associated gastric carcinogenesis.

  20. Detouring the Undesired Route of Helicobacter pylori-Induced Gastric Carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun-Hee; Hong, Kyung-Sook; Hong, Hua [Lab of Translational Medicine, Lee Gil Ya Cancer and Diabetes Institute, Gachon University of Medicine and Science, 7-45 Songdo-dong, Yeonsu-gu, Incheon 406-840 (Korea, Republic of); Hahm, Ki Baik, E-mail: hahmkb@gachon.ac.kr [Lab of Translational Medicine, Lee Gil Ya Cancer and Diabetes Institute, Gachon University of Medicine and Science, 7-45 Songdo-dong, Yeonsu-gu, Incheon 406-840 (Korea, Republic of); Department of Gastroenterology, Gachon Graduate School of Medicine, Gil Hospital, Incheon 406-840 (Korea, Republic of)

    2011-07-25

    Epidemiological and experimental evidence has emerged that a dysregulated inflammation is associated with most of the tumors, and many studies have begun to unravel the molecular pathways linking inflammation and cancer. As a typical example linking these associations, Helicobacter pylori (H. pylori) infection-associated atrophic gastritis has been recognized as precursor lesion of gastric cancer. The identification of transcription factors such as NF-κB and STAT3, and their gene products such as IL-8, COX-2, iNOS, cytokines, chemokines and their receptors, etc have laid the molecular foundation for our understanding of the decisive role of inflammation in carcinogenesis. In addition to the role as the initiator of cancer, inflammation contributes to survival and proliferation of malignant cells, tumor angiogenesis, and even metastasis. In this review, the fundamental mechanisms of H. pylori-induced carcinogenesis as well as the possibility of cancer prevention through suppressing H. pylori-induced inflammation are introduced. We infer that targeting inflammatory pathways have a potential role to detour the unpleasant journey to H. pylori-associated gastric carcinogenesis.

  1. Defining the role of polyamines in colon carcinogenesis using mouse models

    Directory of Open Access Journals (Sweden)

    Natalia A Ignatenko

    2011-01-01

    Full Text Available Genetics and diet are both considered important risk determinants for colorectal cancer, a leading cause of death in the US and worldwide. Genetically engineered mouse (GEM models have made a significant contribution to the characterization of colorectal cancer risk factors. Reliable, reproducible, and clinically relevant animal models help in the identification of the molecular events associated with disease progression and in the development of effictive treatment strategies. This review is focused on the use of mouse models for studying the role of polyamines in colon carcinogenesis. We describe how the available mouse models of colon cancer such as the multiple intestinal neoplasia (Min mice and knockout genetic models facilitate understanding of the role of polyamines in colon carcinogenesis and help in the development of a rational strategy for colon cancer chemoprevention.

  2. Alert-QSAR. Implications for Electrophilic Theory of Chemical Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Vasile Ostafe

    2011-08-01

    Full Text Available Given the modeling and predictive abilities of quantitative structure activity relationships (QSARs for genotoxic carcinogens or mutagens that directly affect DNA, the present research investigates structural alert (SA intermediate-predicted correlations ASA of electrophilic molecular structures with observed carcinogenic potencies in rats (observed activity, A = Log[1/TD50], i.e., ASA=f(X1SA,X2SA,.... The present method includes calculation of the recently developed residual correlation of the structural alert models, i.e., ARASA=f(A-ASA,X1SA,X2SA,... . We propose a specific electrophilic ligand-receptor mechanism that combines electronegativity with chemical hardness-associated frontier principles, equality of ligand-reagent electronegativities and ligand maximum chemical hardness for highly diverse toxic molecules against specific receptors in rats. The observed carcinogenic activity is influenced by the induced SA-mutagenic intermediate effect, alongside Hansch indices such as hydrophobicity (LogP, polarizability (POL and total energy (Etot, which account for molecular membrane diffusion, ionic deformation, and stericity, respectively. A possible QSAR mechanistic interpretation of mutagenicity as the first step in genotoxic carcinogenesis development is discussed using the structural alert chemoinformation and in full accordance with the Organization for Economic Co-operation and Development QSAR guidance principles.

  3. Alert-QSAR. Implications for Electrophilic Theory of Chemical Carcinogenesis

    Science.gov (United States)

    Putz, Mihai V.; Ionaşcu, Cosmin; Putz, Ana-Maria; Ostafe, Vasile

    2011-01-01

    Given the modeling and predictive abilities of quantitative structure activity relationships (QSARs) for genotoxic carcinogens or mutagens that directly affect DNA, the present research investigates structural alert (SA) intermediate-predicted correlations ASA of electrophilic molecular structures with observed carcinogenic potencies in rats (observed activity, A = Log[1/TD50], i.e., ASA=f(X1SA,X2SA,…)). The present method includes calculation of the recently developed residual correlation of the structural alert models, i.e., ARASA=f(A−ASA,X1SA,X2SA,…). We propose a specific electrophilic ligand-receptor mechanism that combines electronegativity with chemical hardness-associated frontier principles, equality of ligand-reagent electronegativities and ligand maximum chemical hardness for highly diverse toxic molecules against specific receptors in rats. The observed carcinogenic activity is influenced by the induced SA-mutagenic intermediate effect, alongside Hansch indices such as hydrophobicity (LogP), polarizability (POL) and total energy (Etot), which account for molecular membrane diffusion, ionic deformation, and stericity, respectively. A possible QSAR mechanistic interpretation of mutagenicity as the first step in genotoxic carcinogenesis development is discussed using the structural alert chemoinformation and in full accordance with the Organization for Economic Co-operation and Development QSAR guidance principles. PMID:21954348

  4. Carcinogenesis--a new point of view.

    Science.gov (United States)

    Gevorkyan, L; Gambashidze, K

    2014-04-01

    Presented article suggests the novel hypothesis of carcinogenesis, where the key moment for all types (biological, physical, chemical) of carcinogenesis has been discussed. For confirmation of the hypothesis thorough theoretical analysis of the mechanisms of malignant transformation of cells after influence of any type of carcinogens and results of experiments have been presented. Hypothesis highlights are formulated as follows: 1) Covalent bond disorders between S+-methionine and Fe3+ atoms in cytochrome; 2) Electron transport chain blockade with certain ligand after its penetration in cytochrome pocket with further formation of 6th coordination bond between ligand and Fe atom (in one case increase in mitochondrial pH precede-, and in other, it follows electron transport chain blockade in cytochromes); 3) Fe3+ reduction up to Fe2+ leading to blockade of aerobic glycolysis; 4) Decrease in enzyme (Е1-TDP, oxidases etc.) activity due to mitochondrial pH alterations; 5) Production of S-adenosylmethionine owing to lipoic acid amide leading to accumulation of homocysteine in cytoplasm with further penetration in cell nucleus producing DNA mutations; 6) Fe2+ wash-out from cytochrome and its deposition in ferritin.

  5. Concept - or no concept

    DEFF Research Database (Denmark)

    Thorsteinsson, Uffe

    1999-01-01

    Discussion about concept in industrial companies. A method for mapping of managerial concept in specific area is shown......Discussion about concept in industrial companies. A method for mapping of managerial concept in specific area is shown...

  6. Investigating evolutionary perspective of carcinogenesis with single-cell transcriptome analysis

    Institute of Scientific and Technical Information of China (English)

    Xi Zhang; Cheng Zhang; Zhongjun Li; Jiangjian Zhong; Leslie P. Weiner; Jiang F. Zhong

    2013-01-01

    We developed phase-switch microfluidic devices for molecular profiling of a large number of single cells. Whole genome microarrays and RNA-sequencing are commonly used to determine the expression levels of genes in cell lysates (a physical mix of millions of cells) for inferring gene functions. However, cellular heterogeneity becomes an inherent noise in the measurement of gene expression. The unique molecular characteristics of individual cells, as well as the temporal and quantitative information of gene expression in cells, are lost when averaged among all cells in cell lysates. Our single-cell technology overcomes this limitation and enables us to obtain a large number of single-cell transcriptomes from a population of cells. A collection of single-cell molecular profiles allows us to study carcinogenesis from an evolutionary perspective by treating cancer as a diverse population of cells with abnormal molecular characteristics. Because a cancer cellpopulation contains cells at various stages of development toward drug resistance, clustering similar single-cell molecular profiles could reveal how drug-resistant sub-clones evolve during cancer treatment. Here, we discuss how single-celltranscriptome analysis technology could enable the study of carcinogenesis from an evolutionary perspective and the development of drug-resistance in leukemia. The single-cell transcriptome analysis reported here could have a direct and significant impact on current cancer treatments and future personalized cancer therapies.

  7. Molecular Action of a Potential Tumor Suppression in Mammary Carcinogenesis

    Science.gov (United States)

    2006-05-01

    Moreover, by depleting the physiological levels of Tid1 in breast cancer cells using the technique of RNA interference ( RNAi ), we discovered that the...colocalization of Tid1 and ErbB-2 further support the notion that Tid1 interacts with membrane-bound receptors not only in insect cells but also in mammalian...Rozakis-Adcok (McMaster University, Hamilton, Ontario, Canada). RNAi and transfection. RNAi -mediated gene knockdown was done with the 19-nucleotide

  8. Carcinogenesis of basal cell carcinomas: genetics and molecular mechanisms.

    Science.gov (United States)

    Lacour, J P

    2002-04-01

    Basal cell carcinoma (BCC) of the skin is the most common type of cancer in humans. Like squamous cell carcinomas, they are also believed to be ultraviolet (UV)-induced, but several data suggest that some differences might exist in the mechanisms of their UV induction. The originating cells may arise from interfollicular basal cells, hair follicles or sebaceous glands, thus from a deeper zone than the SCC ones, which probably means exposure to different doses or wavelengths of UV. The p53 gene and the patched gene (PTCH) are major targets of UV for BCC induction. Mutations in p53 are present in about 56% of human BCC, even small early lesions. The "UV signature" is observed in 65% of them. Mutations in the PTCH play also a major role in BCC development, being responsible for hereditary BCCs in Gorlin's syndrome, sporadic BCC, and BCCs isolated from xeroderma pigmentosum, although with a lower incidence of "UV signature". Smoothened-activating mutations and PTCH2 mutations are also involved in BCC formation. Transgenic mice overexpressing Smoothened or Sonic hedgehog in the skin spontaneously produce skin lesions resembling human BCCs, but contrary to findings in the hairless albino mouse and with SCC, no data on experimental UV induction of BCCs are available.

  9. Molecular genetics of pancreatic carcinogenesis and their clinical significance

    NARCIS (Netherlands)

    Ottenhof, N.A.

    2012-01-01

    Like all types of cancer, pancreatic ductal adenocarcinoma (PDAC), the most common pancreatic malignancy, is a disease of the genes and the genetic alterations that are involved in the development of PDAC have been under investigation for many years. The research described in this thesis focuses on

  10. Oxidative stress and inflammation in liver carcinogenesis

    Directory of Open Access Journals (Sweden)

    Natalia Olaya

    2007-02-01

    series of transcription factors. Moreover, in addition to direct production of ROS by these pathogens, liver infiltration by activated phagocytic cells provides an additional source of ROS production that promotes oxidative stress via interleukin or NO production that can damage proteins, lipids and DNA.

    Nuclear MSI was demonstrated first in familial hereditary colorectal cancer (HNPCC and then in sporadic cancers, primarily digestive tract cancers such as colorectal, gastric and pancreatic cancers.In HCC, although nuclear MSI has been shown in some studies (15,18, there is as yet no direct evidence of alteration of the MMR genes and the biological and the clinicopathological significance of the lowlevel MSI seen in HCC is unclear. MSI has also been shown to occur in inflammatory tissues such as chronic hepatitis and cirrhosis as well as in ulcerative colitis, chronic pancreatitis and in non digestive inflammatory diseases such as rheumatoid arthritis.

    Recently, the role of mitochondria in carcinogenesis has been under numerous investigation, in part because their prominent role in apoptosis, ROS production and other aspects of tumour biology. The mitochondrial genome is particularly susceptible to mutations because of the high level of ROS generation in this organelle, coupled with a relatively low level of DNA repair. Somatic mutations of mitochondrial DNA (mtDNA have been shown in HCC as was also observed MSI. These findings suggest a potential role for mitochondrial genome instability in the early steps of tumorigenesis.

    Ischemia-reperfusion injury can occur in several situations and is a major cause of cell damage during surgery. Cells and tissues subjected to hypoxia by prolonged ischemia become acidic

  11. Environmental Epigenetics and a Unified Theory of the Molecular Aspects of Evolution: A Neo-Lamarckian Concept that Facilitates Neo-Darwinian Evolution.

    Science.gov (United States)

    Skinner, Michael K

    2015-04-26

    Environment has a critical role in the natural selection process for Darwinian evolution. The primary molecular component currently considered for neo-Darwinian evolution involves genetic alterations and random mutations that generate the phenotypic variation required for natural selection to act. The vast majority of environmental factors cannot directly alter DNA sequence. Epigenetic mechanisms directly regulate genetic processes and can be dramatically altered by environmental factors. Therefore, environmental epigenetics provides a molecular mechanism to directly alter phenotypic variation generationally. Lamarck proposed in 1802 the concept that environment can directly alter phenotype in a heritable manner. Environmental epigenetics and epigenetic transgenerational inheritance provide molecular mechanisms for this process. Therefore, environment can on a molecular level influence the phenotypic variation directly. The ability of environmental epigenetics to alter phenotypic and genotypic variation directly can significantly impact natural selection. Neo-Lamarckian concept can facilitate neo-Darwinian evolution. A unified theory of evolution is presented to describe the integration of environmental epigenetic and genetic aspects of evolution.

  12. Role of retinoic receptors in lung carcinogenesis

    Directory of Open Access Journals (Sweden)

    Renyi-Vamos Ferenc

    2008-07-01

    Full Text Available Abstract Several in vitro and in vivo studies have examined the positive and negative effects of retinoids (vitamin A analogs in premalignant and malignant lesions. Retinoids have been used as chemopreventive and anticancer agents because of their pleiotropic regulator function in cell differentiation, growth, proliferation and apoptosis through interaction with two types of nuclear receptors: retinoic acid receptors and retinoid X receptors. Recent investigations have gradually elucidated the function of retinoids and their signaling pathways and may explain the failure of earlier chemopreventive studies. In this review we have compiled basic and recent knowledge regarding the role of retinoid receptors in lung carcinogenesis. Sensitive and appropriate biological tools are necessary for screening the risk population and monitoring the efficacy of chemoprevention. Investigation of retinoid receptors is important and may contribute to the establishment of new strategies in chemoprevention for high-risk patients and in the treatment of lung cancer.

  13. Epigenetic regulation of human DCLK-1 gene during colon-carcinogenesis: clinical and mechanistic implications

    Science.gov (United States)

    O’Connell, Malaney; Shubhashish, Sarkar

    2016-01-01

    Colorectal carcinogenesis is a multi-step process. While ~25% of colorectal cancers (CRCs) arise in patients with a family history (genetic predisposition), ~75% of CRCs are due to age-associated accumulation of epigenetic alterations which can result in the suppression of key tumor suppressor genes leading to mutations and activation of oncogenic pathways. Sporadic colon-carcinogenesis is facilitated by many molecular pathways of genomic instability which include chromosomal instability (CIN), micro-satellite instability (MSI) and CpG island methylator phenotype (CIMP), leading towards loss of homeostasis and onset of neoplastic transformation. The unopposed activation of Wnt/β-catenin pathways, either due to loss of APC function or up-regulation of related stimulatory pathways, results in unopposed hyperproliferation of colonic crypts, considered the single most important risk factor for colon carcinogenesis. Hypermethylation of CpG islands within the promoters of specific genes can potentially inactivate DNA repair genes and/or critical tumor suppressor genes. Recently, CpG methylation of the 5’ promoter of human (h) DCLK1 gene was reported in many human epithelial cancers, including colorectal cancers (CRCs), resulting in the loss of expression of the canonical long isoform of DCLK1 (DCLK1-L) in hCRCs. Instead, a shorter isoform of DCLK1 (DCLK1-S) was discovered to be expressed in hCRCs, from an alternate β promoter of DCLKL1-gene; the clinical and biological implications of these novel findings, in relation to recent publications is discussed. PMID:27777940

  14. Catalytic NH3 Synthesis using N2 /H2 at Molecular Transition Metal Complexes: Concepts for Lead Structure Determination using Computational Chemistry.

    Science.gov (United States)

    Hölscher, Markus; Leitner, Walter

    2017-01-09

    While industrial NH3 synthesis based on the Haber-Bosch-process was invented more than a century ago, there is still no molecular catalyst available which reduces N2 in the reaction system N2 /H2 to NH3 . As the many efforts of experimentally working research groups to develop a molecular catalyst for NH3 synthesis from N2 /H2 have led to a variety of stoichiometric reductions it seems justified to undertake the attempt of systematizing the various approaches of how the N2 molecule might be reduced to NH3 with H2 at a transition metal complex. In this contribution therefore a variety of intuition-based concepts are presented with the intention to show how the problem can be approached. While no claim for completeness is made, these concepts intend to generate a working plan for future research. Beyond this, it is suggested that these concepts should be evaluated with regard to experimental feasibility by checking barrier heights of single reaction steps and also by computation of whole catalytic cycles employing density functional theory (DFT) calculations. This serves as a tool which extends the empirically driven search process and expands it by computed insights which can be used to rationalize the various challenges which must be met.

  15. Epstein-Barr virus in hepatocellular carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    Wei Li; Bao-An Wu; Yong-Ming Zeng; Guang-Can Chen; Xin-Xin Li; Jun-Tian Chen; Yu-Wen Guo; Man-Hong Li; Yi Zeng

    2004-01-01

    AIM: In recent years, studies have suggested that EpsteinBart virus (EBV) is associated with HCC. The present study was to determine the prevalence of EBV in HCC patients,and whether EBV acted synergistically with hepatitis viruses in HCC carcinogenesis.METHODS: Liver tissue 115 HCC patients and 26 noncarcinoma patients were studied. Polymerase chain reaction (PCR) was performed to detect EBV BamHI W DNA, EBV LMP1 DNA, HBV X DNA, and HBV S DNA. Reverse transcription PCR (RT-PCR) was performed to detect HCV RNA and HDV RNA. Immunohistochemistry was performed to detect LMP1,HBsAg, HBcAg and HCV. The positive ratios were compared between HCC group and control group by χ2 test.RESULTS: Totally, 78 HCC samples whose β-globulin DNA was positively detected by amplified PCR were selected.PCR was performed in all cases for EBV DNA and HBV DNA.RT-PCR was performed in 18 cases for HCV RNA and HDV RNA. EBV BanHI W and EBV LMP1 were positive in 18 and 6 cases, respectively. HBV X gene and HBV S gene were positive in 42 and 27 cases respectively. HCV was positive in one of the 18 cases, and none was positive for HDV. The positive rates were 28.2% (22 of 78) for EBV DNA (BamHI W and/or LMP1) and 56.4% (44 of 78) for HBV DNA (X gene and/or S gene) respectively. In addition, 12 cases were positive for both EBV DNA and HBV DNA. Among the 26 cases in the control group, 2 cases were positive for EBV BamHI W, 4positive for HBV X gene and 3 positive for HBV S gene. The positive rates were 8.0% (2 of 26) and 23.1% (6 of 26),respectively, for EBV DNA and HBV DNA. The result of DNA sequencing of BamHI W was 100% homologous with the corresponding sequence of B95-8. There was significant difference in EBV infection rate between HCC patients and controls (χ2 = 4.622, P<0.05). The difference in HBV infection rate was also significant (χ2 = 8.681, P<0.05). However, there was no obvious correlation between HBV and EBV in HCC patients (χ2 = 0.835,P>0.05). LMP1, HBV (HBsAg, HBc

  16. Diet-related DNA adduct formation in relation to carcinogenesis.

    Science.gov (United States)

    Hemeryck, Lieselot Y; Vanhaecke, Lynn

    2016-08-01

    The human diet contributes significantly to the initiation and promotion of carcinogenesis. It has become clear that the human diet contains several groups of natural foodborne chemicals that are at least in part responsible for the genotoxic, mutagenic, and carcinogenic potential of certain foodstuffs. Electrophilic chemicals are prone to attack nucleophilic sites in DNA, resulting in the formation of altered nucleobases, also known as DNA adducts. Since DNA adduct formation is believed to signal the onset of chemically induced carcinogenesis, the DNA adduct-inducing potential of certain foodstuffs has been investigated to gain more insight into diet-related pathways of carcinogenesis. Many studies have investigated diet-related DNA adduct formation. This review summarizes work on known or suspected dietary carcinogens and the role of DNA adduct formation in hypothesized carcinogenesis pathways.

  17. Cell Selection as Driving Force in Lung and Colon Carcinogenesis

    OpenAIRE

    Schöllnberger, Helmut; Beerenwinkel, Niko; Hoogenveen, Rudolf; Vineis, Paolo

    2010-01-01

    Carcinogenesis is the result of mutations and subsequent clonal expansions of mutated, selectively advantageous cells. To investigate the relative contributions of mutation versus cell selection in tumorigenesis, we compared two mathematical models of carcinogenesis in two different cancer types: lung and colon. One approach is based on a population genetics model, the Wright-Fisher process, whereas the other approach is the two-stage clonal expansion model. We compared the dynamics of tumori...

  18. The Concept of Density Functional Theory Based Descriptors and its Relation with the Reactivity of Molecular Systems: A Semi-Quantitative Study

    Directory of Open Access Journals (Sweden)

    Sourav Pal

    2002-04-01

    Full Text Available Abstract: In this present paper, we have made an attempt to explain the theoretical basis for the empirical hardness/softness concepts to address the reactivity of molecular complexes in a semi-quantitative way within the framework of density functional theory. A model based on local hard-soft-acid-base principle has been proposed. The results obtained using some prototype charge transfer complexes, Lewis acid-base complexes and hydrogen-bonded complexes as examples, are in good agreement with the standard ab initio values. Although the model contains ad hoc parameters, it may form the basis of semi-quantitative description of inter-molecular interactions using hardness/softness parameters. The limitation, weakness and other critical issues of the present model are also discussed.

  19. Comfrey (Symphytum officinale. L. and Experimental Hepatic Carcinogenesis: A Short-Term Carcinogenesis Model Study

    Directory of Open Access Journals (Sweden)

    Maria Fernanda Pereira Lavieri Gomes

    2010-01-01

    Full Text Available Comfrey or Symphytum officinale (L. (Boraginaceae is a very popular plant used for therapeutic purposes. Since the 1980s, its effects have been studied in long-term carcinogenesis studies, in which Comfrey extract is administered at high doses during several months and the neoplastic hepatic lesions are evaluated. However, the literature on this topic is very poor considering the studies performed under short-term carcinogenesis protocols, such as the ‘resistant hepatocyte model’ (RHM. In these studies, it is possible to observe easily the phenomena related to the early phases of tumor development, since pre-neoplastic lesions (PNLs rise in about 1–2 months of chemical induction. Herein, the effects of chronic oral treatment of rats with 10% Comfrey ethanolic extract were evaluated in a RHM. Wistar rats were sequentially treated with N-nitrosodiethylamine (ip and 2-acetilaminofluorene (po, and submitted to hepatectomy to induce carcinogenesis promotion. Macroscopic/microscopic quantitative analysis of PNL was performed. Non-parametric statistical tests (Mann–Whitney and χ2 were used, and the level of significance was set at P ≤ 0.05. Comfrey treatment reduced the number of pre-neoplastic macroscopic lesions up to 1 mm (P ≤ 0.05, the percentage of oval cells (P = 0.0001 and mitotic figures (P = 0.007, as well as the number of Proliferating Cell Nuclear Antigen (PCNA positive cells (P = 0.0001 and acidophilic pre-neoplastic nodules (P = 0.05. On the other hand, the percentage of cells presenting megalocytosis (P = 0.0001 and vacuolar degeneration (P = 0.0001 was increased. Scores of fibrosis, glycogen stores and the number of nucleolus organizing regions were not altered. The study indicated that oral treatment of rats with 10% Comfrey alcoholic extract reduced cell proliferation in this model.

  20. Multistage chemical carcinogenesis in mouse skin

    Energy Technology Data Exchange (ETDEWEB)

    Slaga, T.J.; Fischer, S.M.; Weeks, C.E.; Klein-Szanto, A.J.P.

    1979-01-01

    Skin tumors in mice can be induced by the sequential application of a subthreshold dose of a carcinogen (initiation phase) followed by repetitive treatment with a noncarcinogenic tumor promoter. The initiation phase requires only a single application of either a direct acting carcinogen or a procarcinogen which has to be metabolized before being active and is essentially an irreversible step which probably involves a somatic cell mutation. There is a good correlation between the skin tumor initiating activites of several polycyclic aromatic hydrocarbons (PAH) and their ability to bind covalently to epidermal DNA. Laboratory results suggest that bay region diol-epoxides are the ultimate carcinogenic form of PAH carcinogens. Potent inhibitors and stimulators of PAH tumor initiation appear to affect the level of the PAH diol-epoxide reacting with specific DNA bases. Reecent data suggests that the tumor promotion stage involves at least three important steps: (1) the induction of embryonic looking cells (dark cells) in adult epidermis; (2) an increased production of epidermal prostaglandins and polyamines; (3) sustained proliferation of dark cells. Retinoic acid specifically inhibits step two whereas the anti-inflammatory steriod fluocinolone acetonide is a potent inhibitor of steps one and three. The mechanism and the importance of a specific sequence for each step in chemical carcinogenesis in mouse skin are detailed.

  1. Stress and radiation carcinogenesis in mice

    Energy Technology Data Exchange (ETDEWEB)

    Kalisnik, M.; Vraspir-Porenta, O.; Kham-Lindtner, T.; Logonder-Mlinsek, M.; Skrk, J.; Pajntar, M. (Ljubljana Univ. (Yugoslavia). Medicinski Fakultet)

    1981-01-01

    In the present experiment irritation consisting of the combination of an optic signal followed by a mild electric shock administered at regular intervals was started in 2 groups of animals at the age of 3 months. At 4 months of age, one of the irritated and one of the non-irritated groups were exposed to whole-body gamma irradiation with 20 daily doses of 0.5 Gy (50 rad), 1.4 Gy/min (140 rad/min), while the other 2 groups were sham-irradiated. The animals were autopsied and the specimens were microscopically studied for the presence of malignant tumors. Malignant tumors particularly involving the testes and lungs, and leukosis were found in 29% of males, whereas in females the tumor incidence with mammary, pulmonary and ovarian involvement and leukosis was 39%. The irradiation decreased the minimum latency time in the irritated males and both female groups. In males, the irritation lowered the cumulative prevalence of malignant tumors, a significant decrease being noted at the age of 15 months. In females, it was increased, with a significant rise observed to occur at the end of the experiment. The opposite effects of irritation on the radiation carcinogenesis in males and females can be attributed to the radiation-induced specific alterations of the gonads in females and, in part, to a longer survival time observed in the irradiated females.

  2. Hypoxia and Angiogenesis in Endometrioid Endometrial Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Nicole Horrée

    2007-01-01

    Full Text Available Background: Hypoxia-inducible factor 1α (HIF-1α plays an essential role in the adaptive response of cells to hypoxia, triggering biologic events associated with aggressive tumor behavior. Methods: Expression of HIF-1α and proteins in the HIF-1α pathway (Glut-1, CAIX, VEGF in paraffin-embedded specimens of normal (n = 17, premalignant (n = 17 and endometrioid endometrial carcinoma (n = 39 was explored by immunohistochemistry, in relation to microvessel density (MVD. Results: HIF-1α overexpression was absent in inactive endometrium but present in hyperplasia (61% and carcinoma (87%, with increasing expression in a perinecrotic fashion pointing to underlying hypoxia. No membranous expression of Glut-1 and CAIX was noticed in inactive endometrium, in contrast with expression in hyperplasia (Glut-1 0%, CAIX 61%, only focal and diffuse and carcinoma (Glut-1 94.6%, CAIX 92%, both mostly perinecrotically. Diffuse HIF-1α was accompanied by activation of downstream targets. VEGF was significantly higher expressed in hyperplasias and carcinomas compared to inactive endometrium. MVD was higher in hyperplasias and carcinomas than in normal endometrium (p < 0.001. Conclusion: HIF-1α and its downstream genes are increasingly expressed from normal through premalignant to endometrioid adenocarcinoma of the endometrium, paralleled by activation of its downstream genes and increased angiogenesis. This underlines the potential importance of hypoxia and its key regulator HIF-1α in endometrial carcinogenesis.

  3. Wnt signaling and colon carcinogenesis: Beyond APC

    Directory of Open Access Journals (Sweden)

    Rani Najdi

    2011-01-01

    Full Text Available Activation of the Wnt signaling pathway via mutation of the adenomatous polyposis coli gene (APC is a critical event in the development of colon cancer. For colon carcinogenesis, however, constitutive signaling through the canonical Wnt pathway is not a singular event. Here we review how canonical Wnt signaling is modulated by intracellular LEF/TCF composition and location, the action of different Wnt ligands, and the secretion of Wnt inhibitory molecules. We also review the contributions of non-canonical Wnt signaling and other distinct pathways in the tumor micro environment that cross-talk to the canonical Wnt pathway and thereby influence colon cancer progression. These ′non-APC′ aspects of Wnt signaling are considered in relation to the development of potential agents for the treatment of patients with colon cancer. Regulatory pathways that influence Wnt signaling highlight how it might be possible to design therapies that target a network of signals beyond that of APC and β-catenin.

  4. Mouse endogenous retroviral long terminal repeat (LTR) elements and environmental carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Yang, W.K.; Ch' ang, L-Y; Myer, F.E.; Yang, M.D.; Koh, C.K.

    1988-01-01

    For the past several years, the working hypothesis of this laboratory has been that chromosomal retrovirus-related gene elements play important roles in gene-rearrangement and gene-activation events of carcinogenesis and mutagenesis induced by environmental agents. This working hypothesis is based on the concept of transposable genes as well as the recent understanding of retroviruses (RNA tumor viruses) in relation to the carcinogenesis problem. Activation of transposable gene elements has been discussed from the viewpoint of unprogrammed genomic changes in response to unanticipated genomic shocks. This view was used in considering the possibility of transposable gene elements involved in genetic changes of cancer formation in the animal. In this regard, this concept is similar to the perspectives of RNA tumor viruses, the oncogene-virogene hypothesis, and the provirus hypothesis because retroviruses replicate through DNA forms that carry long terminal repeat (LTR) sequences resembling the insertion sequences (or the IS elements) of prokaryotic transposons. The finding of oncogene myc activation in avian leukosis virus-induced leukemogenesis and proviral insertion in the mouse dilute locus mutation have also pointed to the functional similarity between retroviruses and transposable genes.

  5. Magnesium: its role in nutrition and carcinogenesis.

    Science.gov (United States)

    Blaszczyk, Urszula; Duda-Chodak, Aleksandra

    2013-01-01

    Magnesium (Mg2+) plays a key role in many essential cellular processes such as intermediary metabolism, DNA replication and repair, transporting potassium and calcium ions, cell proliferation together with signalling transduction. Dietary sources rich in magnesium are whole and unrefined grains, seeds, cocoa, nuts, almonds and green leafy vegetables. Hard water is also considered to be an important source of magnesium beneficial to human health. The daily dietary intake of magnesium is however frequently found to be below that recommended in Western countries. Indeed, it is recognised that magnesium deficiency may lead to many disorders of the human body, where for instance magnesium depletion is believed to play an important role in the aetiology of the following; cardiovascular disease (including thrombosis, atherosclerosis, ishaemic heart disease, myocardial infarction, hypertension, arrhythmias and congestive heart failure in human), as well as diabetes mellitus, gastrointestinal (GI) tract disease, liver cirrhosis and diseases of the thyroid and parathyroid glands. Insufficient dietary intake of magnesium may also significantly affect the development and exacerbation ofADHD (Attention Deficit- Hyperactivity Disorder) symptoms in children. The known links between magnesium and carcinogenesis still remain unclear and complex, with conflicting results being reported from many experimental, epidemiological and clinical studies; further knowledge is thus required. Mg2+ ions are enzyme cofactors involved in DNA repair mechanisms that maintain genomic stability and fidelity. Any magnesium deficiencies could thereby cause a dysfunction of these systems to occur leading to DNA mutations. Magnesium deficiency may also be associated with inflammation and increased levels of free radicals where both inflammatory mediators and free radicals so arising could cause oxidative DNA damage and therefore tumour formation. The presented review article now provides a summary

  6. Expression Patterns of Cancer Stem Cell Markers During Specific Celecoxib Therapy in Multistep Rat Colon Carcinogenesis Bioassays.

    Science.gov (United States)

    Salim, Elsayed I; Hegazi, Mona M; Kang, Jin Seok; Helmy, Hager M

    2016-01-01

    The purpose of this study was to investigate the role of colon cancer stem cells (CSCs) during chemicallyinduced rat multi-step colon carcinogenesis with or without the treatment with a specific cyclooxygenase-2 inhibitor drug (celecoxib). Two experiments were performed, the first, a short term 12 week colon carcinogenesis bioassay in which only surrogate markers for colon cancer, aberrant crypt foci (ACF) lesions, were formed. The other experiment was a medium term colon cancer rat assay in which tumors had developed after 32 weeks. Treatment with celecoxib lowered the numbers of ACF, as well as the tumor volumes and multiplicities after 32 weeks. Immunohistochemical proliferating cell nuclear antigen (PCNA) labeling indexes LI (%) were downregulated after treatment by celecoxib. Also different cell surface antigens known to associate with CSCs such as the epithelial cell adhesion molecule (EpCAM), CD44 and CD133 were compared between the two experiments and showed differential expression patterns depending on the stage of carcinogenesis and treatment with celecoxib. Flow cytometric analysis demonstrated that the numbers of CD133 cells were increased in the colonic epithelium after 12 weeks while those of CD44 but not CD133 cells were increased after 32 weeks. Moreover, aldehyde dehydrogenase-1 activity levels in the colonic epithelium (a known CSC marker) detected by ELISA assay were found down-regulated after 12 weeks, but were up-regulated after 32 weeks. The data have also shown that the protective effect of celecoxib on these specific markers and populations of CSCs and on other molecular processes such as apoptosis targeted by this drug may vary depending on the genetic and phenotypic stages of carcinogenesis. Therefore, uncovering these distinction roles of CSCs during different phases of carcinogenesis and during specific treatment could be useful for targeted therapy.

  7. Linking DNA adduct formation and human cancer risk in chemical carcinogenesis.

    Science.gov (United States)

    Poirier, Miriam C

    2016-08-01

    Over two centuries ago, Sir Percival Pott, a London surgeon, published a pioneering treatise showing that soot exposure was the cause of high incidences of scrotal cancers occurring in young men who worked as chimney sweeps. Practicing at a time when cellular pathology was not yet recognized, Sir Percival nonetheless observed that the high incidence and short latency of the chimney sweep cancers, was fundamentally different from the rare scrotal cancers typically found in elderly men. Furthermore, his diagnosis that the etiology of these cancers was related to chimney soot exposure, was absolutely accurate, conceptually novel, and initiated the field of "occupational cancer epidemiology." After many intervening years of research focused on mechanisms of chemical carcinogenesis, briefly described here, it is clear that DNA damage, or DNA adduct formation, is "necessary but not sufficient" for tumor induction, and that many additional factors contribute to carcinogenesis. This review includes a synopsis of carcinogen-induced DNA adduct formation in experimental models and in the human population, with particular attention paid to molecular dosimetry and molecular cancer epidemiology. Environ. Mol. Mutagen. 57:499-507, 2016. © 2016 Wiley Periodicals, Inc.

  8. Deficiency of CCAAT/enhancer binding protein family DNA binding prevents malignant conversion of adenoma to carcinoma in NNK-induced lung carcinogenesis in the mouse

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    Kimura Shioko

    2012-12-01

    Full Text Available Abstract Background The CCAAT/enhancer binding proteins (C/EBPs play important roles in carcinogenesis of many tumors including the lung. Since multiple C/EBPs are expressed in lung, the combinatorial expression of these C/EBPs on lung carcinogenesis is not known. Methods A transgenic mouse line expressing a dominant negative A-C/EBP under the promoter of lung epithelial Clara cell secretory protein (CCSP gene in doxycycline dependent fashion was subjected to 4-(methylnitrosamino-1-(3-pyridyl-1-butanone (NNK-induced lung carcinogenesis bioassay in the presence and absence of doxycycline, and the effect of abolition of DNA binding activities of C/EBPs on lung carcinogenesis was examined. Results A-C/EBP expression was found not to interfere with tumor development; however, it suppressed the malignant conversion of adenoma to carcinoma during NNK-induced lung carcinogenesis. The results suggested that Ki67 may be used as a marker for lung carcinomas in mouse. Conclusions The DNA binding of C/EBP family members can be used as a potential molecular target for lung cancer therapy.

  9. Carcinogenesis of the Oral Cavity: Environmental Causes and Potential Prevention by Black Raspberry.

    Science.gov (United States)

    El-Bayoumy, Karam; Chen, Kun-Ming; Zhang, Shang-Min; Sun, Yuan-Wan; Amin, Shantu; Stoner, Gary; Guttenplan, Joseph B

    2017-01-17

    Worldwide, cancers of the oral cavity and pharynx comprise the sixth most common malignancies. Histologically, more than 90% of oral cancers are squamous cell carcinoma (SCC). Epidemiologic data strongly support the role of exogenous factors such as tobacco, alcohol, and human papilloma virus infection as major causative agents. Avoidance of risk factors has only been partially successful, and survival rates have not improved despite advances in therapeutic approaches. Therefore, new or improved approaches to prevention and/or early detection are critical. Better understanding of the mechanisms of oral carcinogenesis can assist in the development of novel biomarkers for early detection and strategies for disease prevention. Toward this goal, several animal models for carcinogenesis in the oral cavity have been developed. Among these are xenograft, and transgenic animal models, and others employing the synthetic carcinogens such as 7,12-dimethylbenz[a]anthracene in hamster cheek pouch and 4-nitroquinoline-N-oxide in rats and mice. Additional animal models employing environmental carcinogens such as benzo[a]pyrene and N'-nitrosonornicotine have been reported. Each model has certain advantages and disadvantages. Models that (1) utilize environmental carcinogens, (2) reflect tumor heterogeneity, and (3) accurately represent the cellular and molecular changes involved in the initiation and progression of oral cancer in humans could provide a realistic platform. To achieve this goal, we introduced a novel nonsurgical mouse model to study oral carcinogenesis induced by dibenzo[a,l]pyrene (DB[a,l]P), an environmental pollutant and tobacco smoke constituent, and its diol epoxide metabolite (±)-anti-11,12-dihydroxy-13,14-epoxy-11,12,13,14-tetrahydrodibenzo[a,l]pyrene [(±)-anti-DB[a,l]PDE]. On the basis of a detailed comparison of oral cancer induced by DB[a,l]P with that induced by the other above-mentioned oral carcinogens with respect to dose, duration, species and

  10. Current concepts in the diagnosis of blood stream infections. Are novel molecular methods useful in clinical practice?

    Science.gov (United States)

    Huttunen, Reetta; Syrjänen, Jaana; Vuento, Risto; Aittoniemi, Janne

    2013-11-01

    The decision on the right empirical treatment in bacteremia places particular demands on the clinician. As long as no microbiological diagnosis can be immediately drawn, the clinical diagnosis together with knowledge of local antimicrobial resistance must determine the antimicrobial choice. The use of several amplification, hybridization, and mass spectrometry methods has been studied in patient cohorts in comparison with blood culture-based conventional techniques. However, no clinical outcome trials have been conducted in which the use of these novel methods would guide antimicrobial therapy. Local differences in bacterial antimicrobial resistance cause differences in the regional need for molecular methods for the early detection of resistance mechanisms. The implementation of novel methods in clinical use requires active discussion between laboratory experts and clinicians. Providing rapid susceptibility results using conventional methods can lead to timely changes to appropriate antimicrobial therapy and the costs are lower than with the molecular methods. Gram-stain information in combination with clinical data is an underestimated, underused, rapid, and economical means of assessing the etiology of blood stream infection.

  11. Downstream carcinogenesis signaling pathways by green tea polyphenols: a translational perspective of chemoprevention and treatment for cancers.

    Science.gov (United States)

    Hu, Guohua; Zhang, Lei; Rong, Yefei; Ni, Xiaoling; Sun, Yihong

    2014-01-01

    Green tea is one of the most popular beverages around the world. For several decades, numerous epidemiological, preclinical and clinical studies have demonstrated that green tea polyphenols (GTPs), especially epigallocatechin-3-gallate (EGCG) have cancer-preventing effects on various cancers. In this review, we present inhibition of carcinogenesis in different animal models by GTPs or EGCG, including prostate cancer, bladder cancer, breast cancer, intestinal cancer, colon cancer, gastric cancer, lung cancer, oral cancer and skin cancer. In vitro studies showed that GTPs/EGCG potently induces apoptosis, cell cycle arrest and suppresses metastasis in tumor cells but not in their normal cell counterparts. The molecular mechanisms of these activities are discussed in detail to elucidate GTPs/EGCG downstream carcinogenesis signaling pathways and their values of perspective of chemoprevention and treatment for cancers.

  12. Mouse Models for Efficacy Testing of Agents against Radiation Carcinogenesis — A Literature Review

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    Leena Rivina

    2012-12-01

    Full Text Available As the number of cancer survivors treated with radiation as a part of their therapy regimen is constantly increasing, so is concern about radiation-induced cancers. This increases the need for therapeutic and mitigating agents against secondary neoplasias. Development and efficacy testing of these agents requires not only extensive in vitro assessment, but also a set of reliable animal models of radiation-induced carcinogenesis. The laboratory mouse (Mus musculus remains one of the best animal model systems for cancer research due to its molecular and physiological similarities to man, small size, ease of breeding in captivity and a fully sequenced genome. This work reviews relevant M. musculus inbred and F1 hybrid animal models and methodologies of induction of radiation-induced leukemia, thymic lymphoma, breast, and lung cancer in these models. Where available, the associated molecular pathologies are also included.

  13. Concept and approach of human signal-molecular-profiling database: a pilot study on depression using Lab-on-chips.

    Science.gov (United States)

    Dong, Tao; Zhao, Xinyan; Yang, Zhaochu

    2013-01-01

    Signal molecular profiling (SMP) in serum can reveal abundant medical information about the human body. The construction of a human signal-molecular-profiling database (HSMPD) will greatly prompt the research of medical science. However, some challenges hinder the construction of HSMPD. A promising strategy is proposed to provide a convenient way for the establishment of HSMPD. Firstly, a low-cost and high-throughput tool for measuring SMP should be developed and standardized. When the SMP-oriented tools were accepted by most hospitals worldwide, SMP information will be decoded by a cloud-based system and stored into the online database naturally. In the pilot study, an ultrasensitive Lab-on-chips (LOC) device was developed as a specific tool for SMP. Clinical serum samples from 10 women within 4 weeks of giving birth, including 2 patients with postpartum depression were studied by the LOC devices, since accumulating evidence has indicated that hormones and cytokines in patients with mood disorders are abnormal. HSMPD may be applied to diagnose depression in the future. Here, five kinds of signal molecules were quantified on the devices, namely, tumor necrosis factor-alpha (TNF-α), thyroid-stimulating hormone (TSH), interleukin (IL)-2, IL-6 and IL-8. The preliminary results showed that the concentrations of IL-2 and IL-8 in the depression group may be higher than those in the control group, whereas the other kinds of signal molecules did not change significantly. Although the correlations are not enough to induct any diagnostic criterion, the SMP-oriented tool was verified. The results also indicated that the strategy to establish HSMPD is conceivable.

  14. New concepts in molecular imaging: non-invasive MRI spotting of proteolysis using an Overhauser effect switch.

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    Philippe Mellet

    Full Text Available BACKGROUND: Proteolysis, involved in many processes in living organisms, is tightly regulated in space and time under physiological conditions. However deregulation can occur with local persistent proteolytic activities, e.g. in inflammation, cystic fibrosis, tumors, or pancreatitis. Furthermore, little is known about the role of many proteases, hence there is a need of new imaging methods to visualize specifically normal or disease-related proteolysis in intact bodies. METHODOLOGY/PRINCIPAL FINDINGS: In this paper, a new concept for non invasive proteolysis imaging is proposed. Overhauser-enhanced Magnetic Resonance Imaging (OMRI at 0.2 Tesla was used to monitor the enzymatic hydrolysis of a nitroxide-labeled protein. In vitro, image intensity switched from 1 to 25 upon proteolysis due to the associated decrease in the motional correlation time of the substrate. The OMRI experimental device used in this study is consistent with protease imaging in mice at 0.2 T without significant heating. Simulations show that this enzymatic-driven OMRI signal switch can be obtained at lower frequencies suitable for larger animals or humans. CONCLUSIONS/SIGNIFICANCE: The method is highly sensitive and makes possible proteolysis imaging in three dimensions with a good spatial resolution. Any protease could be targeted specifically through the use of taylor-made cleavable macromolecules. At short term OMRI of proteolysis may be applied to basic research as well as to evaluate therapeutic treatments in small animal models of experimental diseases.

  15. The Dual Role of Inflammation in Colon Carcinogenesis

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    Carmine Stolfi

    2012-09-01

    Full Text Available Chronic inflammation characterizing patients with inflammatory bowel disease (IBD represents a major risk factor for the development of colorectal cancer. Mechanisms underlying this neoplastic transformation are not fully understood though studies in experimental models of colon carcinogenesis suggest that inflammatory cell-derived cytokines either directly or indirectly stimulate the uncontrolled growth of cancer cells. Nevertheless, under specific inflammatory conditions, immune cells can boost an anti-tumor immune response with the down-stream effect of eliminating dysplastic and cancerous cells. This review outlines the beneficial and detrimental role of inflammation in colon carcinogenesis.

  16. Are the somatic mutation and tissue organization field theories of carcinogenesis incompatible?

    Science.gov (United States)

    Rosenfeld, Simon

    2013-01-01

    Two drastically different approaches to understanding the forces driving carcinogenesis have crystallized through years of research. These are the somatic mutation theory (SMT) and the tissue organization field theory (TOFT). The essence of SMT is that cancer is derived from a single somatic cell that has successively accumulated multiple DNA mutations, and that those mutations occur on genes which control cell proliferation and cell cycle. Thus, according to SMT, neoplastic lesions are the results of DNA-level events. Conversely, according to TOFT, carcinogenesis is primarily a problem of tissue organization: carcinogenic agents destroy the normal tissue architecture thus disrupting cell-to-cell signaling and compromising genomic integrity. Hence, in TOFT the DNA mutations are the effect, and not the cause, of the tissue-level events. Cardinal importance of successful resolution of the TOFT versus SMT controversy dwells in the fact that, according to SMT, cancer is a unidirectional and mostly irreversible disease; whereas, according to TOFT, it is curable and reversible. In this paper, our goal is to outline a plausible scenario in which TOFT and SMT can be reconciled using the framework and concepts of the self-organized criticality (SOC), the principle proven to be extremely fruitful in a wide range of disciplines pertaining to natural phenomena, to biological communities, to large-scale social developments, to technological networks, and to many other subjects of research.

  17. Novel Concepts for Drug Hypersensitivity Based on the Use of Long-Time Scale Molecular Dynamic Simulation

    Science.gov (United States)

    Murai, Takahiro; Kawashita, Norihito

    2016-01-01

    The discovery that several drug hypersensitivity reactions (DHRs) are associated with specific human leukocyte antigen (HLA) alleles has attracted increasing research interest. However, the underlying mechanisms of these HLA-induced DHRs remain unclear, especially for drug-induced immediate activation of T-cell clones (TCCs). Recently, a novel hypothesis involving partial detachment between self-peptide(s) and the HLA molecule (altered peptide-HLA (pHLA) model) has been proposed to explain these phenomena. In order to clarify this hypothesis, we performed long-timescale molecular dynamics (MD) simulations. We focused on HLA-B⁎57:01-restricted abacavir hypersensitivity reactions (AHRs), one of the most famous DHRs. One of the simulation results showed that this altered-pHLA model might be driven by an increase in the distance not only between HLA and self-peptides but also between the α1 and α2 helices of HLA. Our findings provide novel insights into abacavir-induced immediate activation of TCCs and these findings might also be applied to other DHRs, such as HLA-B⁎58:01-restricted allopurinol hypersensitivity reactions. PMID:27999707

  18. Novel Concepts for Drug Hypersensitivity Based on the Use of Long-Time Scale Molecular Dynamic Simulation

    Directory of Open Access Journals (Sweden)

    Takahiro Murai

    2016-01-01

    Full Text Available The discovery that several drug hypersensitivity reactions (DHRs are associated with specific human leukocyte antigen (HLA alleles has attracted increasing research interest. However, the underlying mechanisms of these HLA-induced DHRs remain unclear, especially for drug-induced immediate activation of T-cell clones (TCCs. Recently, a novel hypothesis involving partial detachment between self-peptide(s and the HLA molecule (altered peptide-HLA (pHLA model has been proposed to explain these phenomena. In order to clarify this hypothesis, we performed long-timescale molecular dynamics (MD simulations. We focused on HLA-B⁎57:01-restricted abacavir hypersensitivity reactions (AHRs, one of the most famous DHRs. One of the simulation results showed that this altered-pHLA model might be driven by an increase in the distance not only between HLA and self-peptides but also between the α1 and α2 helices of HLA. Our findings provide novel insights into abacavir-induced immediate activation of TCCs and these findings might also be applied to other DHRs, such as HLA-B⁎58:01-restricted allopurinol hypersensitivity reactions.

  19. Femtosecond Laser Spectroscopy of the Rhodopsin Photochromic Reaction: A Concept for Ultrafast Optical Molecular Switch Creation (Ultrafast Reversible Photoreaction of Rhodopsin

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    Olga Smitienko

    2014-11-01

    Full Text Available Ultrafast reverse photoreaction of visual pigment rhodopsin in the femtosecond time range at room temperature is demonstrated. Femtosecond two-pump probe experiments with a time resolution of 25 fs have been performed. The first рump pulse at 500 nm initiated cis-trans photoisomerization of rhodopsin chromophore, 11-cis retinal, which resulted in the formation of the primary ground-state photoproduct within a mere 200 fs. The second pump pulse at 620 nm with a varying delay of 200 to 3750 fs relative to the first рump pulse, initiated the reverse phototransition of the primary photoproduct to rhodopsin. The results of this photoconversion have been observed on the differential spectra obtained after the action of two pump pulses at a time delay of 100 ps. It was found that optical density decreased at 560 nm in the spectral region of bathorhodopsin absorption and increased at 480 nm, where rhodopsin absorbs. Rhodopsin photoswitching efficiency shows oscillations as a function of the time delay between two рump pulses. The quantum yield of reverse photoreaction initiated by the second pump pulse falls within the range 15% ± 1%. The molecular mechanism of the ultrafast reversible photoreaction of visual pigment rhodopsin may be used as a concept for the development of an ultrafast optical molecular switch.

  20. Insights into the field carcinogenesis of ovarian cancer based on the nanocytology of endocervical and endometrial epithelial cells

    Science.gov (United States)

    Damania, Dhwanil; Roy, Hemant K.; Kunte, Dhananja; Hurteau, Jean A.; Subramanian, Hariharan; Cherkezyan, Lusik; Krosnjar, Nela; Shah, Maitri; Backman, Vadim

    2013-01-01

    Ovarian cancer ranks fifth in cancer fatalities among American women. Although curable at early stages with surgery, most women are diagnosed with symptoms of late-stage metastatic disease. Moreover, none of the current diagnostic techniques are clinically recommended for at-risk women as they preferentially target low-grade tumors (which do not affect longevity) and fail to capture early signatures of more lethal serous tumors which originate in the fimbrae region of the fallopian tubes. Hence, the early detection of ovarian cancer is challenging given the current strategy. Recently, our group has developed a novel optical imaging technique, partial wave spectroscopic (PWS) microscopy, that can quantify the nanoscale macromolecular density fluctuations within biological cells via a biomarker, disorder strength (Ld). Using the concept of field carcinogenesis, we propose a method of detecting ovarian cancer by PWS assessment of endometrial and endocervical columnar cells. The study includes 26 patients (controls = 15, cancer = 11) for endometrium and 23 (controls = 13, cancer = 10) for endocervix. Our results highlight a significant increase in Ld (% fold-increase > 50%, P-value < 0.05) for columnar epithelial cells obtained from cancer patients compared to controls for both endocervix and endometrium. Overall, the quantification of field carcinogenic events in the endometrium and the novel observation of its extension to the cervix are unique findings in the understanding of ovarian field carcinogenesis. We further show independent validation of the presence of cervical field carcinogenesis with mico-RNA expression data. PMID:23436651

  1. Widespread hypomethylation occurs early and synergizes with gene amplification during esophageal carcinogenesis.

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    Hector Alvarez

    2011-03-01

    Full Text Available Although a combination of genomic and epigenetic alterations are implicated in the multistep transformation of normal squamous esophageal epithelium to Barrett esophagus, dysplasia, and adenocarcinoma, the combinatorial effect of these changes is unknown. By integrating genome-wide DNA methylation, copy number, and transcriptomic datasets obtained from endoscopic biopsies of neoplastic progression within the same individual, we are uniquely able to define the molecular events associated progression of Barrett esophagus. We find that the previously reported global hypomethylation phenomenon in cancer has its origins at the earliest stages of epithelial carcinogenesis. Promoter hypomethylation synergizes with gene amplification and leads to significant upregulation of a chr4q21 chemokine cluster and other transcripts during Barrett neoplasia. In contrast, gene-specific hypermethylation is observed at a restricted number of loci and, in combination with hemi-allelic deletions, leads to downregulatation of selected transcripts during multistep progression. We also observe that epigenetic regulation during epithelial carcinogenesis is not restricted to traditionally defined "CpG islands," but may also occur through a mechanism of differential methylation outside of these regions. Finally, validation of novel upregulated targets (CXCL1 and 3, GATA6, and DMBT1 in a larger independent panel of samples confirms the utility of integrative analysis in cancer biomarker discovery.

  2. Downregulation of keratin 76 expression during oral carcinogenesis of human, hamster and mouse.

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    Srikant Ambatipudi

    Full Text Available BACKGROUND: Keratins are structural marker proteins with tissue specific expression; however, recent reports indicate their involvement in cancer progression. Previous study from our lab revealed deregulation of many genes related to structural molecular integrity including KRT76. Here we evaluate the role of KRT76 downregulation in oral precancer and cancer development. METHODS: We evaluated KRT76 expression by qRT-PCR in normal and tumor tissues of the oral cavity. We also analyzed K76 expression by immunohistochemistry in normal, oral precancerous lesion (OPL, oral squamous cell carcinoma (OSCC and in hamster model of oral carcinogenesis. Further, functional implication of KRT76 loss was confirmed using KRT76-knockout (KO mice. RESULTS: We observed a strong association of reduced K76 expression with increased risk of OPL and OSCC development. The buccal epithelium of DMBA treated hamsters showed a similar trend. Oral cavity of KRT76-KO mice showed preneoplastic changes in the gingivobuccal epithelium while no pathological changes were observed in KRT76 negative tissues such as tongue. CONCLUSION: The present study demonstrates loss of KRT76 in oral carcinogenesis. The KRT76-KO mice data underlines the potential of KRT76 being an early event although this loss is not sufficient to drive the development of oral cancers. Thus, future studies to investigate the contributing role of KRT76 in light of other tumor driving events are warranted.

  3. Multifaceted role of TREX2 in the skin defense against UV-induced skin carcinogenesis.

    Science.gov (United States)

    Manils, Joan; Gómez, Diana; Salla-Martret, Mercè; Fischer, Heinz; Fye, Jason M; Marzo, Elena; Marruecos, Laura; Serrano, Inma; Salgado, Rocío; Rodrigo, Juan P; Garcia-Pedrero, Juana M; Serafin, Anna M; Cañas, Xavier; Benito, Carmen; Toll, Agustí; Forcales, Sònia-Vanina; Perrino, Fred W; Eckhart, Leopold; Soler, Concepció

    2015-09-08

    TREX2 is a 3'-DNA exonuclease specifically expressed in keratinocytes. Here, we investigated the relevance and mechanisms of TREX2 in ultraviolet (UV)-induced skin carcinogenesis. TREX2 expression was up-regulated by chronic UV exposure whereas it was de-regulated or lost in human squamous cell carcinomas (SCCs). Moreover, we identified SNPs in the TREX2 gene that were more frequent in patients with head and neck SCCs than in healthy individuals. In mice, TREX2 deficiency led to enhanced susceptibility to UVB-induced skin carcinogenesis which was preceded by aberrant DNA damage removal and degradation as well as reduced inflammation. Specifically, TREX2 loss diminished the up-regulation of IL12 and IFNγ, key cytokines related to DNA repair and antitumor immunity. In UV-treated keratinocytes, TREX2 promoted DNA repair and passage to late apoptotic stages. Notably, TREX2 was recruited to low-density nuclear chromatin and micronuclei, where it interacted with phosphorylated H2AX histone, which is a critical player in both DNA repair and cell death. Altogether, our data provide new insights in the molecular mechanisms of TREX2 activity and establish cell autonomous and non-cell autonomous functions of TREX2 in the UVB-induced skin response.

  4. Can systems toxicology identify common biomarkers of non-genotoxic carcinogenesis?

    Science.gov (United States)

    Plant, Nick

    2008-12-30

    For the rapid development of safe, efficacious chemicals it is important that any potential liabilities are identified as early as possible in the discovery/development pipeline. Once identified it is then possible to make rational decisions on whether to progress a chemical and/or series further; one such liability is chemical carcinogenesis, a highly undesirable characteristic in a novel chemical entity. Chemical carcinogens may be roughly divided into two classes, those that elicit their actions through direct damage to DNA (genotoxic carcinogens) and those that cause carcinogenesis through mechanisms that involve direct damage of the DNA by the agent (non-genotoxic carcinogens). Whereas the former group can be identified by in vitro screens to a good degree of accuracy, the latter group are far more problematic due to their diverse modes of action. This review will focus on the latter class of chemical carcinogens, examining how modern '-omic' technologies have begun to identify signatures that may represent sensitive, early markers for these processes. In addition to their use in signature generation the role of -omic level approaches to delineating molecular mechanisms of action will also be discussed.

  5. Biomolecular and epidemiological aspects of human papillomavirus induced cervical carcinogenesis

    NARCIS (Netherlands)

    Vermeulen, Christine Frederike Wilhelmine

    2007-01-01

    Cervical cancer remains one of the leading causes of death from cancer among women worldwide. Organised screening programmes aim to trace precursor lesions in order to reduce cervical cancer incidence. Human papillomavirus (HPV) is a necessary cause for cervical carcinogenesis. Most HPV infections a

  6. Carcinogenesis explained within the context of a theory of organisms.

    Science.gov (United States)

    Sonnenschein, Carlos; Soto, Ana M

    2016-10-01

    For a century, the somatic mutation theory (SMT) has been the prevalent theory to explain carcinogenesis. According to the SMT, cancer is a cellular problem, and thus, the level of organization where it should be studied is the cellular level. Additionally, the SMT proposes that cancer is a problem of the control of cell proliferation and assumes that proliferative quiescence is the default state of cells in metazoa. In 1999, a competing theory, the tissue organization field theory (TOFT), was proposed. In contraposition to the SMT, the TOFT posits that cancer is a tissue-based disease whereby carcinogens (directly) and mutations in the germ-line (indirectly) alter the normal interactions between the diverse components of an organ, such as the stroma and its adjacent epithelium. The TOFT explicitly acknowledges that the default state of all cells is proliferation with variation and motility. When taking into consideration the principle of organization, we posit that carcinogenesis can be explained as a relational problem whereby release of the constraints created by cell interactions and the physical forces generated by cellular agency lead cells within a tissue to regain their default state of proliferation with variation and motility. Within this perspective, what matters both in morphogenesis and carcinogenesis is not only molecules, but also biophysical forces generated by cells and tissues. Herein, we describe how the principles for a theory of organisms apply to the TOFT and thus to the study of carcinogenesis.

  7. Hypoxia and cell cycle deregulation in endometrial carcinogenesis

    NARCIS (Netherlands)

    Horrée, N.

    2007-01-01

    Because uterine endometrial carcinoma is the most common malignancy of the female genital tract and 1 of every 5 patients dies of this disease, understanding the mechanisms of carcinogenesis and progression of endometrial carcinoma is important. In general, this thesis can be summarized as a study o

  8. Carcinogenesis related to intense pulsed light and UV exposure

    DEFF Research Database (Denmark)

    Hedelund, L; Lerche, C; Wulf, H C;

    2006-01-01

    This study examines whether intense pulsed light (IPL) treatment has a carcinogenic potential itself or may influence ultraviolet (UV)-induced carcinogenesis. Secondly, it evaluates whether UV exposure may influence IPL-induced side effects. Hairless, lightly pigmented mice (n=144) received three...

  9. Death receptors and ligands in cervical carcinogenesis : an immunohistochemical study

    NARCIS (Netherlands)

    Reesink-Peters, N; Hougardy, B M T; van den Heuvel, F A J; Ten Hoor, K A; Hollema, H; Boezen, H M; de Vries, E G E; de Jong, S; van der Zee, A G J

    2005-01-01

    OBJECTIVE: Increasing imbalance between proliferation and apoptosis is important in cervical carcinogenesis. The death ligands FasL and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induce apoptosis by binding to their cognate cell-surface death receptors Fas or death receptor (DR)

  10. Role of colonic microbiota in colorectal carcinogenesis: a systematic review

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    Marta Borges-Canha

    2015-11-01

    Full Text Available Background and aim: The human colonic mucosa is populated by a wide range of microorganisms, usually in a symbiotic relation with the host. Sometimes this balance is lost and a state of dysbiosis arises, exposing the colon to different metabolic and inflammatory stimuli (according to the microbiota's changing profile. Recent findings lead to hypothesize that this unbalance may create a subclinical pro-inflammatory state that increases DNA mutations and, therefore, colorectal carcinogenesis. In this article we aim to systematically review the scientific evidence regarding colonic microbiota and its role in colorectal carcinogenesis. Methods: Systematic review of PubMed searching results for original articles studying microbiota and colorectal cancer until November 2014. Results: Thirty-one original articles studied the role of colon microbiota in colorectal carcinoma including both human and animal studies. Different and heterogeneous methods were used and different bacteria were considered. Nevertheless, some bacteria are consistently augmented (such as Fusobacteria, Alistipes, Porphyromonadaceae, Coriobacteridae, Staphylococcaceae, Akkermansia spp. and Methanobacteriales, while other are constantly diminished in colorectal cancer (such as Bifidobacterium, Lactobacillus, Ruminococcus, Faecalibacterium spp., Roseburia, and Treponema. Moreover, bacteria metabolites amino acids are increased and butyrate is decreased throughout colonic carcinogenesis. Conclusion: Conclusive evidence shows that colorectal carcinogenesis is associated with microbial dysbiosis. This information may be used to create new prophylactic, diagnostic and therapeutic strategies for colorectal cancer.

  11. The glutathione biotransformation system and colon carcinogenesis in human

    NARCIS (Netherlands)

    Grubben, M.J.A.L.; Nagengast, F.M.; Katan, M.B.; Peters, W.H.M.

    2001-01-01

    Evidence for a protective role of the glutathione biotransformation system in carcinogenesis is growing. However, most data on this system in relation to colorectal cancer originate from animal studies. Here we review the human data. In humans, a significant association was found between glutathione

  12. Distinct response of the hepatic transcriptome to Aflatoxin B1 induced hepatocellular carcinogenesis and resistance in rats

    Science.gov (United States)

    Shi, Jiejun; He, Jiangtu; Lin, Jing; Sun, Xin; Sun, Fenyong; Ou, Chao; Jiang, Cizhong

    2016-01-01

    Aflatoxin is a natural potent carcinogen and a major cause of liver cancer. However, the molecular mechanisms of hepatocellular carcinogenesis remain largely unexplored. In this study, we profiled global gene expression in liver tissues of rats that developed hepatocellular carcinoma (HCC) from aflatoxin B1 (AFB1) administration and those that were AFB1-resistant, as well as rats without AFB1 exposure as a control. AFB1 exposure resulted in extensive perturbation in gene expression with different functions in HCC and AFB1 resistance (AR) samples. The differentially expressed genes (DEGs) in HCC sample were enriched for cell proliferation, cell adhesion and vasculature development that largely contribute to carcinogenesis. Anti-apoptosis genes were up-regulated in HCC sample whereas apoptosis-induction genes were up-regulated in AR sample. AFB1 exposure also caused extensive alteration in expression level of lncRNAs. Among all the 4511 annotated lncRNAs, half of them were highly expressed only in HCC sample and up-regulated a group of protein-coding genes with cancer-related functions: apoptosis regulation, DNA repair, and cell cycle. Intriguingly, these genes were down-regulated by lncRNAs highly expressed in AR sample. Collectively, apoptosis is the critical biological process for carcinogenesis in response to AFB1 exposure through changes in expression level of both protein-coding and lncRNA genes. PMID:27545718

  13. Widespread hypomethylation occurs early and synergizes with gene amplification during esophageal carcinogenesis

    DEFF Research Database (Denmark)

    Alvarez, Hector; Opalinska, Joanna; Zhou, Li

    2011-01-01

    Although a combination of genomic and epigenetic alterations are implicated in the multistep transformation of normal squamous esophageal epithelium to Barrett esophagus, dysplasia, and adenocarcinoma, the combinatorial effect of these changes is unknown. By integrating genome-wide DNA methylation......, copy number, and transcriptomic datasets obtained from endoscopic biopsies of neoplastic progression within the same individual, we are uniquely able to define the molecular events associated progression of Barrett esophagus. We find that the previously reported global hypomethylation phenomenon...... in cancer has its origins at the earliest stages of epithelial carcinogenesis. Promoter hypomethylation synergizes with gene amplification and leads to significant upregulation of a chr4q21 chemokine cluster and other transcripts during Barrett neoplasia. In contrast, gene-specific hypermethylation...

  14. Oxidative stress and cyclooxygenase activity in prostate carcinogenesis: targets for chemopreventive strategies.

    Science.gov (United States)

    Pathak, S K; Sharma, R A; Steward, W P; Mellon, J K; Griffiths, T R L; Gescher, A J

    2005-01-01

    Over the last decade, epidemiological, experimental and clinical studies have implicated oxidative stress in the development and progression of prostate cancer. Oxidative stress may be linked to the effects of androgens, anti-oxidant systems and the pre-malignant condition, high-grade prostatic intraepithelial neoplasia. Cyclooxygenase-2 activity has been linked with prostate carcinogenesis. Evidence suggests that oxidative stress and cyclo-oxygenase-2 activity may be mechanistically linked. Agents such as anti-oxidants and cyclo-oxgenase-2 inhibitors may be of value in the chemoprevention of prostate cancer. The feasibility of intervention with such agents will depend on the development and validation of biomarkers for clinical trials, particularly markers of oxidative damage caused by reactive oxygen species (ROS). A greater understanding of the molecular events associated with oxidative stress will enhance the development of such biomarkers and should result in better strategies for the chemoprevention of prostate cancer.

  15. Colorectal carcinogenesis-update and perspectives

    DEFF Research Database (Denmark)

    Raskov, Hans; Pommergaard, Hans-Christian; Burcharth, Jakob;

    2014-01-01

    . The major genetic pathways of CRC are the Chromosome Instability Pathway representing the pathway of sporadic CRC through the K-ras, APC, and P53 mutations, and the Microsatellite Instability Pathway representing the pathway of hereditary non-polyposis colon cancer through mutations in mismatch repair genes......Colorectal cancer (CRC) is a very common malignancy in the Western World and despite advances in surgery, chemotherapy and screening, it is still the second leading cause of cancer deaths in this part of the world. Numerous factors are found important in the development of CRC including colonocyte....... To identify early cancers, screening programs have been initiated, and the leading strategy has been the use of faecal occult blood testing followed by colonoscopy in positive cases. Regarding the treatment of colorectal cancer, significant advances have been made in the recent decade. The molecular targets...

  16. Role of microsatellites instability in carcinogenesis of postcricoid carcinoma on top of plummer-vinson syndrome.

    Science.gov (United States)

    Badawy, Badawy Shahat; Ahmad, Mohamed Abdel-Kader; Sayed, Ramadan Hashem; Habib, Tito Naeem

    2010-10-01

    To develop a molecular pattern that might help in understanding carcinogenesis of postcricoid carcinoma (PCC) on top of Plummer-Vinson syndrome (PVS) in a prospective controlled study. Twenty-four patients with PVS were diagnosed and followed up over a 4 year period, during which eight of them showed malignant change to PCC. Twenty volunteers free of neoplastic diseases were included as a control group. In the two groups, DNA extraction from mononuclear peripheral blood cells, and analysis of loss of heterozygosity (LOH) and microsatellite instability (MSI) using six paired simple tandem repeats (STRs) primers were done. The molecular weight of each STRs locus was scored and statistical correlations were performed. LOH occurred in 55.6 and 72.9% of PVS and PCC cases compared to 25% of control group. At loci D17S695, D9S753 and D9S171, LOH occurred in 54.2, 66.7, and 70.8% of PVS cases; and in 62.5% of PCC cases for each locus compared to 15, 25 and 45% of control cases. D3S1286 and CFS1-R displayed the highest frequency of LOH in PCC (100% for each) while recorded in 58.3 and 33.3% in PVS compared to 30 and 0% in control cases. Certain genetic events tend to occur as early and late events in malignant change of PVS to PCC. Detection of these events may help in understanding carcinogenesis and in early detection of malignancy. CFS1-R is the most informative marker of tumor progression.

  17. Modelling carcinogenesis after radiotherapy using Poisson statistics: implications for IMRT, protons and ions.

    Science.gov (United States)

    Jones, Bleddyn

    2009-06-01

    Current technical radiotherapy advances aim to (a) better conform the dose contours to cancers and (b) reduce the integral dose exposure and thereby minimise unnecessary dose exposure to normal tissues unaffected by the cancer. Various types of conformal and intensity modulated radiotherapy (IMRT) using x-rays can achieve (a) while charged particle therapy (CPT)-using proton and ion beams-can achieve both (a) and (b), but at greater financial cost. Not only is the long term risk of radiation related normal tissue complications important, but so is the risk of carcinogenesis. Physical dose distribution plans can be generated to show the differences between the above techniques. IMRT is associated with a dose bath of low to medium dose due to fluence transfer: dose is effectively transferred from designated organs at risk to other areas; thus dose and risk are transferred. Many clinicians are concerned that there may be additional carcinogenesis many years after IMRT. CPT reduces the total energy deposition in the body and offers many potential advantages in terms of the prospects for better quality of life along with cancer cure. With C ions there is a tail of dose beyond the Bragg peaks, due to nuclear fragmentation; this is not found with protons. CPT generally uses higher linear energy transfer (which varies with particle and energy), which carries a higher relative risk of malignant induction, but also of cell death quantified by the relative biological effect concept, so at higher dose levels the frank development of malignancy should be reduced. Standard linear radioprotection models have been used to show a reduction in carcinogenesis risk of between two- and 15-fold depending on the CPT location. But the standard risk models make no allowance for fractionation and some have a dose limit at 4 Gy. Alternatively, tentative application of the linear quadratic model and Poissonian statistics to chromosome breakage and cell kill simultaneously allows estimation of

  18. Epigenetic targets of arsenic: emphasis on epigenetic modifications during carcinogenesis.

    Science.gov (United States)

    Roy, Ram Vinod; Son, Young-Ok; Pratheeshkumar, Poyil; Wang, Lei; Hitron, John Andrew; Divya, Sasidharan Padmaja; D, Rakesh; Kim, Donghern; Yin, Yuanqin; Zhang, Zhuo; Shi, Xianglin

    2015-01-01

    DNA methylation and histone modification promote opening and closure of chromatin structure, which affects gene expression without altering the DNA sequence. Epigenetic markers regulate the dynamic nature of chromatin structure at different levels: DNA, histone, noncoding RNAs, as well as the higher-order chromatin structure. Accumulating evidence strongly suggests that arsenic-induced carcinogenesis involves frequent changes in the epigenetic marker. However, progress in identifying arsenic-induced epigenetic changes has already been made using genome-wide approaches; the biological significance of these epigenetic changes remains unknown. Moreover, arsenic-induced changes in the chromatin state alter gene expression through the epigenetic mechanism. The current review provides a summary of recent literature regarding epigenetic changes caused by arsenic in carcinogenesis. We highlight the transgenerational studies needed to explicate the biological significance and toxicity of arsenic over a broad spectrum.

  19. Cervical Carcinogenesis and Immune Response Gene Polymorphisms: A Review

    Science.gov (United States)

    Mooij, Merel

    2017-01-01

    The local immune response is considered a key determinant in cervical carcinogenesis after persistent infection with oncogenic, high-risk human papillomavirus (HPV) infections. Genetic variation in various immune response genes has been shown to influence risk of developing cervical cancer, as well as progression and survival among cervical cancer patients. We reviewed the literature on associations of immunogenetic single nucleotide polymorphism, allele, genotype, and haplotype distributions with risk and progression of cervical cancer. Studies on HLA and KIR gene polymorphisms were excluded due to the abundance on literature on that subject. We show that multiple genes and loci are associated with variation in risk of cervical cancer. Rather than one single gene being responsible for cervical carcinogenesis, we postulate that variations in the different immune response genes lead to subtle differences in the effectiveness of the antiviral and antitumour immune responses, ultimately leading to differences in risk of developing cervical cancer and progressive disease after HPV infection. PMID:28280748

  20. Cervical Carcinogenesis and Immune Response Gene Polymorphisms: A Review

    Directory of Open Access Journals (Sweden)

    Akash M. Mehta

    2017-01-01

    Full Text Available The local immune response is considered a key determinant in cervical carcinogenesis after persistent infection with oncogenic, high-risk human papillomavirus (HPV infections. Genetic variation in various immune response genes has been shown to influence risk of developing cervical cancer, as well as progression and survival among cervical cancer patients. We reviewed the literature on associations of immunogenetic single nucleotide polymorphism, allele, genotype, and haplotype distributions with risk and progression of cervical cancer. Studies on HLA and KIR gene polymorphisms were excluded due to the abundance on literature on that subject. We show that multiple genes and loci are associated with variation in risk of cervical cancer. Rather than one single gene being responsible for cervical carcinogenesis, we postulate that variations in the different immune response genes lead to subtle differences in the effectiveness of the antiviral and antitumour immune responses, ultimately leading to differences in risk of developing cervical cancer and progressive disease after HPV infection.

  1. The Thymus in Experimental Mammary Carcinogenesis and Polychemotherapy.

    Science.gov (United States)

    Kazakov, O V; Kabakov, A V; Ishchenko, I Yu; Poveshchenko, A F; Raiter, T V; Strunkin, D N; Michurina, S V; Konenkov, V I

    2017-02-01

    Histological study of structural transformations in the thymus of Wistar females in induced carcinogenesis (N-methyl-N-nitrosourea injection in the right 2-nd mamma) and polychemotherapy (6 months after tumor growth initiation; cyclophosphamide, methotrexate, and 5-fluorouracyl) was carried out. The area of the cortical matter in the thymus decreased 6 months after carcinogenesis induction, the percentage of connective tissue elements and glandular tissue and the counts of immunoblasts and cells with pyknotic nuclei increased, this indicating the development of accidental involution of the thymus. Animals of the experimental tumor+chemotherapy group exhibited morphological signs of lymphocyte migration from the thymus and suppressed activities of the lymphoid and epithelial components (lesser area of connective tissue elements and glandular tissue, lesser density of parenchymatous cell elements, lesser counts of immunoblasts and small lymphocytes, and larger area of the medulla) in comparison with animals without chemotherapy.

  2. The Role of Ubiquitine Proteasome Pathway in Carcinogenesis

    Directory of Open Access Journals (Sweden)

    N.Ceren Sumer Turanligil

    2010-02-01

    Full Text Available Ubiquitin works as a marker protein which targets misfolded or injured proteins to cellular degradation. It brings the abnormal proteins to a subcellular organelle named proteasome and it maintains the degradation of proteins in limited lenghts of peptides by leaving the process withuout being changed. Mistakes in ubiquitin-dependent proteolysis in various steps of carcinogenesis is known. In this review, we dealed with the effects of ubiquitin-proteasome pathway (UPP on carcinogenesis via intercellular signaling molecules like Ras, transcription factors like NF-kB, cytokines like TNF-alfa Tumor necrosis factor, protooncogenes like p53 and MDM2(murine double minute 2, components of cell cycle and DNA repair proteins like BRCA1. We also focused on the relationship of UPP on antigen presentation which is active in immune response and its place in the aetiology of colon cancer to provide a specific example. [Archives Medical Review Journal 2010; 19(1.000: 36-55

  3. Inhibitory effects of acetylsalicylic acid on exocrine pancreatic carcinogenesis.

    Science.gov (United States)

    Yıldız, H; Oztas, H; Yıldız, D; Koc, A; Kalipci, E

    2013-05-01

    We investigated short (6 months) and long (12 months) term inhibitory effects of low (200 ppm) and high (400 ppm) dosages of acetylsalicylic acid (aspirin) on exocrine pancreatic carcinogenesis. It is known that exocrine pancreatic carcinogenesis can be detected by the presence of atypical acinar cell foci (AACF) in pancreas. We investigated possible inhibitory effects of acetylsalicylic acid in an azaserine-treated rat model. AACF were produced in rats by injection with azaserine according to previous studies. Our findings showed that the number, volume and diameter of pancreatic AACF were reduced after acetylsalicylic acid application. These observations suggest that acetylsalicylic acid may exert a protective effect against neoplastic development of pancreatic acinar cells in azaserine injected rats. Our findings corroborate reports in the literature concerning the effects of aspirin in reducing neoplastic development.

  4. Dose-response relationship in multistage carcinogenesis: promoters.

    OpenAIRE

    Kitchin, K T; Brown, J. L.; Setzer, R.W.

    1994-01-01

    Published dose-response curves of promoters of multistage carcinogenesis were selected that met the combined criteria of long study times, multiple doses, and low doses. In rat liver, 12 dose-response studies of 7 different promoters (phenobarbital, 2,3,7,8-tetrachlorodibenzo-p-dioxin [TCDD], clophen A-50 (a polychlorinated biphenyl), alpha-, beta-, and gamma-hexachlorocyclohexane [HCH], and chloroform) were selected. These promoters were studied for 7-86 weeks and either altered hepatic foci...

  5. Experimental gastric carcinogenesis in Cebus apella nonhuman primates.

    Directory of Open Access Journals (Sweden)

    Joana de Fátima Ferreira Borges da Costa

    Full Text Available The evolution of gastric carcinogenesis remains largely unknown. We established two gastric carcinogenesis models in New-World nonhuman primates. In the first model, ACP03 gastric cancer cell line was inoculated in 18 animals. In the second model, we treated 6 animals with N-methyl-nitrosourea (MNU. Animals with gastric cancer were also treated with Canova immunomodulator. Clinical, hematologic, and biochemical, including C-reactive protein, folic acid, and homocysteine, analyses were performed in this study. MYC expression and copy number was also evaluated. We observed that all animals inoculated with ACP03 developed gastric cancer on the 9(th day though on the 14(th day presented total tumor remission. In the second model, all animals developed pre-neoplastic lesions and five died of drug intoxication before the development of cancer. The last surviving MNU-treated animal developed intestinal-type gastric adenocarcinoma observed by endoscopy on the 940(th day. The level of C-reactive protein level and homocysteine concentration increased while the level of folic acid decreased with the presence of tumors in ACP03-inoculated animals and MNU treatment. ACP03 inoculation also led to anemia and leukocytosis. The hematologic and biochemical results corroborate those observed in patients with gastric cancer, supporting that our in vivo models are potentially useful to study this neoplasia. In cell line inoculated animals, we detected MYC immunoreactivity, mRNA overexpression, and amplification, as previously observed in vitro. In MNU-treated animals, mRNA expression and MYC copy number increased during the sequential steps of intestinal-type gastric carcinogenesis and immunoreactivity was only observed in intestinal metaplasia and gastric cancer. Thus, MYC deregulation supports the gastric carcinogenesis process. Canova immunomodulator restored several hematologic measurements and therefore, can be applied during/after chemotherapy to increase the

  6. Experimental Gastric Carcinogenesis in Cebus apella Nonhuman Primates

    Science.gov (United States)

    Silva, Tanielly Cristina Raiol; Andrade Junior, Edilson Ferreira; Rezende, Alexandre Pingarilho; Carneiro Muniz, José Augusto Pereira; Lacreta Junior, Antonio Carlos Cunha; Assumpção, Paulo Pimentel; Calcagno, Danielle Queiroz; Demachki, Samia; Rabenhorst, Silvia Helena Barem; Smith, Marília de Arruda Cardoso; Burbano, Rommel Rodriguez

    2011-01-01

    The evolution of gastric carcinogenesis remains largely unknown. We established two gastric carcinogenesis models in New-World nonhuman primates. In the first model, ACP03 gastric cancer cell line was inoculated in 18 animals. In the second model, we treated 6 animals with N-methyl-nitrosourea (MNU). Animals with gastric cancer were also treated with Canova immunomodulator. Clinical, hematologic, and biochemical, including C-reactive protein, folic acid, and homocysteine, analyses were performed in this study. MYC expression and copy number was also evaluated. We observed that all animals inoculated with ACP03 developed gastric cancer on the 9th day though on the 14th day presented total tumor remission. In the second model, all animals developed pre-neoplastic lesions and five died of drug intoxication before the development of cancer. The last surviving MNU-treated animal developed intestinal-type gastric adenocarcinoma observed by endoscopy on the 940th day. The level of C-reactive protein level and homocysteine concentration increased while the level of folic acid decreased with the presence of tumors in ACP03-inoculated animals and MNU treatment. ACP03 inoculation also led to anemia and leukocytosis. The hematologic and biochemical results corroborate those observed in patients with gastric cancer, supporting that our in vivo models are potentially useful to study this neoplasia. In cell line inoculated animals, we detected MYC immunoreactivity, mRNA overexpression, and amplification, as previously observed in vitro. In MNU-treated animals, mRNA expression and MYC copy number increased during the sequential steps of intestinal-type gastric carcinogenesis and immunoreactivity was only observed in intestinal metaplasia and gastric cancer. Thus, MYC deregulation supports the gastric carcinogenesis process. Canova immunomodulator restored several hematologic measurements and therefore, can be applied during/after chemotherapy to increase the tolerability and

  7. Role of oxidative stress in cadmium toxicity and carcinogenesis

    OpenAIRE

    2009-01-01

    Cadmium (Cd) is a toxic metal, targeting the lung, liver, kidney, and testes following acute intoxication, and causing nephrotoxicity, immunotoxicity, osteotoxicity and tumors after prolonged exposures. Reactive oxygen species (ROS) are often implicated in Cd toxicology. This minireview focused on direct evidence for the generation of free radicals in intact animals following acute Cd overload and discussed the association of ROS in chronic Cd toxicity and carcinogenesis. Cd-generated superox...

  8. Transcriptional regulation of cadherins during development and carcinogenesis

    OpenAIRE

    2004-01-01

    The cadherin superfamily of Ca2+-dependent homophilic adhesion molecules plays a critical role in regulating cell-to-cell interactions. During development, the expression of different cadherins is highly dynamic, since they are associated with the morphogenesis, establishment and/or maintenance of different tissues. Alterations in cadherin expression or function occur frequently during carcinogenesis, such as the loss of the epithelial cadherin (E-cadherin) and/or the aberrant expression of o...

  9. Modulation of carcinogenesis in the urinary bladder by retinoids.

    Science.gov (United States)

    Hicks, R M; Turton, J A; Chowaniec, J; Tomlinson, C N; Gwynne, J; Nandra, K; Chrysostomou, E; Pedrick, M

    1985-01-01

    Bladder cancer has a 70% recurrence rate within five years and a high associated mortality. It commonly occurs in one or both of two predominant growth/behaviour patterns: either well-differentiated, relatively benign exophytic papillary lesions, or flat, poorly differentiated invasive carcinoma usually arising from carcinoma-in-situ. We have used the F344 rat treated with N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) as a model for the papillary disease, and the BBN-treated B6D2F1 mouse for flat, invasive bladder carcinoma. In the rat, carcinogenesis is a multistage process and several retinoids will delay or even halt the development of bladder cancer. Inhibition of carcinogenesis is not complete, but there is a consistent reduction in the time-related incidence of papillomas and carcinomas and a concomitant improvement in the overall differentiation of the urothelium. In the BBN/mouse model, retinoids also have anticarcinogenic activity but interpretation of the results is more complicated. Unlike the F344 rat, the B6D2F1 mouse has a non-uniform response to BBN; not all mice develop bladder cancer even after treatment with very high doses of BBN and in those that do, more than one mechanism of carcinogenesis may be involved. Individual retinoids differ markedly in their ability to modulate bladder carcinogenesis in rodents; the behaviour of one analogue cannot be predicted automatically from data obtained with another. Combined data from rodent trials in this and other laboratories have identified N-(4-hydroxyphenyl)retinamide (HPR) as the most anticarcinogenic retinoid tested so far for the rodent bladder. It is also less toxic in rodents and better tolerated in humans than either 13-cis-retinoic acid or etretinate, two retinoids currently used in dermatological practice. A prophylactic chemopreventive trial of HPR in bladder cancer patients starting in 1985 will be centered on the Middlesex Hospital, London.

  10. Animal Models of Colitis-Associated Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Manasa Kanneganti

    2011-01-01

    Full Text Available Inflammatory bowel disease (IBD is a group of chronic inflammatory disorders that affect individuals throughout life. Although the etiology and pathogenesis of IBD are largely unknown, studies with animal models of colitis indicate that dysregulation of host/microbial interactions are requisite for the development of IBD. Patients with long-standing IBD have an increased risk for developing colitis-associated cancer (CAC, especially 10 years after the initial diagnosis of colitis, although the absolute number of CAC cases is relatively small. The cancer risk seems to be not directly related to disease activity, but is related to disease duration/extent, complication of primary sclerosing cholangitis, and family history of colon cancer. In particular, high levels and continuous production of inflammatory mediators, including cytokines and chemokines, by colonic epithelial cells (CECs and immune cells in lamina propria may be strongly associated with the pathogenesis of CAC. In this article, we have summarized animal models of CAC and have reviewed the cellular and molecular mechanisms underlining the development of carcinogenic changes in CECs secondary to the chronic inflammatory conditions in the intestine. It may provide us some clues in developing a new class of therapeutic agents for the treatment of IBD and CAC in the near future.

  11. Shikonin Suppresses Skin Carcinogenesis via Inhibiting Cell Proliferation.

    Science.gov (United States)

    Li, Wenjuan; Zhang, Chunjing; Ren, Amy; Li, Teena; Jin, Rong; Li, Guohong; Gu, Xin; Shi, Runhua; Zhao, Yunfeng

    2015-01-01

    The M2 isoform of pyruvate kinase M2 (PKM2) has been shown to be up-regulated in human skin cancers. To test whether PKM2 may be a target for chemoprevention, shikonin, a natural product from the root of Lithospermum erythrorhizon and a specific inhibitor of PKM2, was used in a chemically-induced mouse skin carcinogenesis study. The results revealed that shikonin treatment suppressed skin tumor formation. Morphological examinations and immunohistochemical staining of the skin epidermal tissues suggested that shikonin inhibited cell proliferation without inducing apoptosis. Although shikonin alone suppressed PKM2 activity, it did not suppress tumor promoter-induced PKM2 activation in the skin epidermal tissues at the end of the skin carcinogenesis study. To reveal the potential chemopreventive mechanism of shikonin, an antibody microarray analysis was performed, and the results showed that the transcription factor ATF2 and its downstream target Cdk4 were up-regulated by chemical carcinogen treatment; whereas these up-regulations were suppressed by shikonin. In a promotable skin cell model, the nuclear levels of ATF2 were increased during tumor promotion, whereas this increase was inhibited by shikonin. Furthermore, knockdown of ATF2 decreased the expression levels of Cdk4 and Fra-1 (a key subunit of the activator protein 1. In summary, these results suggest that shikonin, rather than inhibiting PKM2 in vivo, suppresses the ATF2 pathway in skin carcinogenesis.

  12. Concept Maps

    OpenAIRE

    Schwendimann, Beat Adrian

    2014-01-01

    A concept map is a node-link diagram showing the semantic relationships among concepts. The technique for constructing concept maps is called "concept mapping". A concept map consists of nodes, arrows as linking lines, and linking phrases that describe the relationship between nodes. Two nodes connected with a labeled arrow are called a proposition. Concept maps are versatile graphic organizers that can represent many different forms of relationships between concepts. The relationship between...

  13. Acyclic retinoid in chemoprevention of hepatocellular carcinoma: Targeting phosphorylated retinoid X receptor-α for prevention of liver carcinogenesis

    Directory of Open Access Journals (Sweden)

    Masahito Shimizu

    2012-01-01

    Full Text Available One of the key features of hepatocellular carcinoma (HCC is the high rate of intrahepatic recurrence that correlates with poor prognosis. Therefore, in order to improve the clinical outcome for patients with HCC, development of a chemopreventive agent that can decrease or delay the incidence of recurrence is a critical issue for urgent investigation. Acyclic retinoid (ACR, a synthetic retinoid, successfully improves HCC patient survival by preventing recurrence and the formation of secondary tumors. A malfunction of the retinoid X receptor-α (RXRα due to phosphorylation by the Ras-MAPK signaling pathway plays a critical role in liver carcinogenesis, and ACR exerts chemopreventive effects on HCC development by inhibiting RXRα phosphorylation. Here, we review the relationship between retinoid signaling abnormalities and liver disease, the mechanisms of how RXRα phosphorylation contributes to liver carcinogenesis, and the detailed effects of ACR on preventing HCC development, especially based on the results of our basic and clinical research. We also outline the concept of "clonal deletion and inhibition" therapy, which is defined as the removal and inhibition of latent malignant clones from the liver before they expand into clinically detectable HCC, because ACR prevents the development of HCC by implementing this concept. Looking toward the future, we discuss "combination chemoprevention" using ACR as a key drug since it can generate a synergistic effect, and may thus be an effective new strategy for the prevention of HCC.

  14. Cyr61/CCN1 signaling is critical for epithelial-mesenchymal transition and stemness and promotes pancreatic carcinogenesis

    Directory of Open Access Journals (Sweden)

    Van Veldhuizen Peter J

    2011-01-01

    Full Text Available Abstract Background Despite recent advances in outlining the mechanisms involved in pancreatic carcinogenesis, precise molecular pathways and cellular lineage specification remains incompletely understood. Results We show here that Cyr61/CCN1 play a critical role in pancreatic carcinogenesis through the induction of EMT and stemness. Cyr61 mRNA and protein were detected in the early precursor lesions and their expression intensified with disease progression. Cyr61/CCN1 expression was also detected in different pancreatic cancer cell lines. The aggressive cell lines, in which the expressions of mesenchymal/stem cell molecular markers are predominant; exhibit more Cyr61/CCN1 expression. Cyr61 expression is exorbitantly higher in cancer stem/tumor initiating Panc-1-side-population (SP cells. Upon Cyr61/CCN1 silencing, the aggressive behaviors are reduced by obliterating interlinking pathobiological events such as reversing the EMT, blocking the expression of stem-cell-like traits and inhibiting migration. In contrast, addition of Cyr61 protein in culture medium augments EMT and stemness features in relatively less aggressive BxPC3 pancreatic cancer cells. Using a xenograft model we demonstrated that cyr61/CCN1 silencing in Panc-1-SP cells reverses the stemness features and tumor initiating potency of these cells. Moreover, our results imply a miRNA-based mechanism for the regulation of aggressive behaviors of pancreatic cancer cells by Cyr61/CCN1. Conclusions In conclusion, the discovery of the involvement of Cyr61/CCN1 in pancreatic carcinogenesis may represent an important marker for PDAC and suggests Cyr61/CCN1 can be a potential cancer therapeutic target.

  15. Carcinogenesis switched on by DNA cross-link between complementary bases aroused by aflatoxin and N-nitroso compounds

    Institute of Scientific and Technical Information of China (English)

    DAI Qianhuan; LU Ping; PENG Shaohua; ZHANG Qingrong

    2003-01-01

    The di-region theory put forward by Dai Qianhuan, a molecular mechanism of chemical carcinogenesis, concluded that the carcinogenesis induced by most of the environmental carcinogens is switched on by the cross-linking between DNA complementary bases aroused by the bifunctional alkylation of their metabolic intermediates. It was evidenced in this paper with DNA filter elution method that one carcinogenic mycotoxin, aflatoxin G1, four carcinogenic N-nitroso compounds, N-nitrosodiethyl-amine, N-nitrosodibutyl-amine, N-nitrosomorpholine and N-nitrosopyrrolidine, one carcinogenic diazo color, 4-dimethylaminodiazobenzene and one carcinogenic nitrogen-containing heterocyclic compound, quinoline, all induced DNA interstrands cross-linking with dosage correlation after metabolic activation. However, the non-carcinogens in corresponding series for control, aflatoxin B2, N-nitroso-diphenylamine, 4′-bromo-4-dimethylaminodiazobenzene and isoquinoline, cannot induce DNA interstrands cross-linking at all in the same condition. A method for the determination of cross-linking ratio between DNA complementary bases in total DNA interstrands cross-linking, which has no monitoring measure as yet, has been established for the first time based upon a 24 hour repairing experiment. The DNA complementary pair cross-linking ratio induced by a metabolized carcinogen is correlated with its carcinogenic potential. It may be concluded that the mutations including point and frameshift mutagenesis induced by aflatoxin and other carcinogens are switched on by their corresponding cross-linking base pair between complementary bases. Therefore, the di-region theory is a reasonable molecular mechanism for chemical, endogenous and physical carcinogenesis.

  16. Identification of novel genes involved in gastric carcinogenesis by suppression subtractive hybridization.

    Science.gov (United States)

    Mottaghi-Dastjerdi, N; Soltany-Rezaee-Rad, M; Sepehrizadeh, Z; Roshandel, G; Ebrahimifard, F; Setayesh, N

    2015-01-01

    Gastric cancer (GC) is one of the most common and life-threatening types of malignancies. Identification of the differentially expressed genes in GC is one of the best approaches for establishing new diagnostic and therapeutic targets. Furthermore, these investigations could advance our knowledge about molecular biology and the carcinogenesis of this cancer. To screen for the overexpressed genes in gastric adenocarcinoma, we performed suppression subtractive hybridization (SSH) on gastric adenocarcinoma tissue and the corresponding normal gastric tissue, and eight genes were found to be overexpressed in the tumor compared with those of the normal tissue. The genes were ribosomal protein L18A, RNase H2 subunit B, SEC13, eukaryotic translation initiation factor 4A1, tetraspanin 8, cytochrome c oxidase subunit 2, NADH dehydrogenase subunit 4, and mitochondrially encoded ATP synthase 6. The common functions among the identified genes include involvement in protein synthesis, involvement in genomic stability maintenance, metastasis, metabolic improvement, cell signaling pathways, and chemoresistance. Our results provide new insights into the molecular biology of GC and drug discovery: each of the identified genes could be further investigated as targets for prognosis evaluation, diagnosis, treatment, evaluation of the response to new anticancer drugs, and determination of the molecular pathogenesis of GC.

  17. Expression of some tumor associated factors in human carcinogenesis and development of gastric carcinoma

    Institute of Scientific and Technical Information of China (English)

    Ming-Dong Zhao; Xue-Mei Hu; Dian-Jing Sun; Qun Zhang; Yu-Hao Zhang; Wei Meng

    2005-01-01

    AIM: To study the effect of IGF-1/IGF-1R and gastrin/ CCK-BR on carcinogenesis and development of human gastric carcinoma and to explore its mechanism and provide a credible theoretical foundation for early diagnosis and molecular therapy of gastric carcinoma. METHODS: mRNA expression levels of IGF-1/IGF-1R and gastrin/CCK-BR were assessed by RT-PCR method in gastric cancer tissues, adjacent mucosa, and tumor-free tissues from 56 patients with gastric carcinoma and normal gastric mucosae from 56 healthy controls. Tissue specimens were obtained by biopsy and confirmed by histological evaluation.RESULTS: The mRNA levels of IGF-1/IGF-1R were increased in gastric cancer tissues compared with normal tissues from healthy controls and successively increased in tumor-free tissues, adjacent mucosa, and gastric cancer tissues. The mRNA levels of gastrin/CCK-BR were increased in gastric cancer tissues compared with normal tissues from healthy controls. There was a significant difference between gastric cancer tissues and adjacent mucosa and tumor-free tissues, but the mRNA levels of gastrin were not significantly increased in adjacent mucosa and gastric cancer tissues compared with tumorfree tissues. The mRNA levels of CCK-BR were increased in gastric cancer tissues and adjacent mucosa compared with tumor-free tissues, but not significantly increased in adjacent mucosa and gastric cancer tissues compared with gastric cancer tissues. CONCLUSION: Overexpression of IGF-1/IGF-1R and gastrin/CCK-BR promotes the disorderly proliferation of gastric mucosa epithelia and it is of great significance in the carcinogenesis and development of gastric carcinoma.

  18. A central role for heme iron in colon carcinogenesis associated with red meat intake.

    Science.gov (United States)

    Bastide, Nadia M; Chenni, Fatima; Audebert, Marc; Santarelli, Raphaelle L; Taché, Sylviane; Naud, Nathalie; Baradat, Maryse; Jouanin, Isabelle; Surya, Reggie; Hobbs, Ditte A; Kuhnle, Gunter G; Raymond-Letron, Isabelle; Gueraud, Françoise; Corpet, Denis E; Pierre, Fabrice H F

    2015-03-01

    Epidemiology shows that red and processed meat intake is associated with an increased risk of colorectal cancer. Heme iron, heterocyclic amines, and endogenous N-nitroso compounds (NOC) are proposed to explain this effect, but their relative contribution is unknown. Our study aimed at determining, at nutritional doses, which is the main factor involved and proposing a mechanism of cancer promotion by red meat. The relative part of heme iron (1% in diet), heterocyclic amines (PhIP + MeIQx, 50 + 25 μg/kg in diet), and NOC (induced by NaNO₂+ NaNO₂; 0.17 + 0.23 g/L of drinking water) was determined by a factorial design and preneoplastic endpoints in chemically induced rats and validated on tumors in Min mice. The molecular mechanisms (genotoxicity, cytotoxicity) were analyzed in vitro in normal and Apc-deficient cell lines and confirmed on colon mucosa. Heme iron increased the number of preneoplastic lesions, but dietary heterocyclic amines and NOC had no effect on carcinogenesis in rats. Dietary hemoglobin increased tumor load in Min mice (control diet: 67 ± 39 mm²; 2.5% hemoglobin diet: 114 ± 47 mm², P = 0.004). In vitro, fecal water from rats given hemoglobin was rich in aldehydes and was cytotoxic to normal cells, but not to premalignant cells. The aldehydes 4-hydroxynonenal and 4-hydroxyhexenal were more toxic to normal versus mutated cells and were only genotoxic to normal cells. Genotoxicity was also observed in colon mucosa of mice given hemoglobin. These results highlight the role of heme iron in the promotion of colon cancer by red meat and suggest that heme iron could initiate carcinogenesis through lipid peroxidation. .

  19. Identification of mammary epithelial cells subject to chronic oxidative stress in mammary epithelium of young women and teenagers living in USA: implication for breast carcinogenesis.

    Science.gov (United States)

    Weisz, Judith; Shearer, Debra A; Murata, Erin; Patrick, Susan D; Han, Bing; Berg, Arthur; Clawson, Gary A

    2012-01-15

    Current knowledge of changes in the mammary epithelium relevant to breast carcinogenesis is limited to when histological changes are already present because of a lack of biomarkers needed to identify where such molecular changes might be ongoing at earlier during the of decades-long latent stages of breast carcinogenesis. Breast reduction tissues from young women and teenagers, representative of USA's high breast cancer incidence population, were studies using immunocytochemistry and targeted PCR arrays in order to learn whether a marker of chronic oxidative-stress [protein adducts of 4-hydroxy-2-nonenal (4HNE)] can identify where molecular changes relevant to carcinogenesis might be taking place prior to any histological changes. 4HNE-immunopositive (4HNE+) mammary epithelial cell-clusters were identified in breast tissue sections from most women and from many teenagers (ages 14-30 y) and, in tissues from women ages 17-27 y with many vs. few 4HNE+ cells, the expression of 30 of 84 oxidative-stress associated genes was decreased and only one was increased > 2-fold. This is in contrast to increased expression of many of these genes known to be elicited by acute oxidative-stress. The findings validate using 4HNE-adducts to identify where molecular changes of potential relevance to carcinogenesis are taking place in histologically normal mammary epithelium and highlight differences between responses to acute vs. chronic oxidative-stress. We posit that the altered gene expression in 4HNE+ tissues reflect adaptive responses to chronic oxidative-stress that enable some cells to evade mechanisms that have evolved to prevent propagation of cells with oxidatively-damaged DNA and to accrue heritable changes needed to establish a cancer.

  20. EXPRESSION OF GST-π GENE IN HUMAN ESOPHAGEAL CARCINOGENESIS

    Institute of Scientific and Technical Information of China (English)

    FU Baojin; ZHANG Yunhan; WANG Yaohe; GAO Dongling; FU Shuli; WEN Xiaogang; ZHANG Sanshen; WANG Jiang

    1999-01-01

    Objective: To investigate the possible role of GSTπ in esophageal carcinogenesis. Methods: GST-πexpression at mRNA level was studied by in situ hybridization (ISH) and at protein level by immunohistochemistry (IHC). GST-π expression in normal epithelial cells (NC) of the esophagus,hyperplastic cells (HC), dysplastic cells (DC) from grade Ⅰ to Ⅲ, carcinoma in situ (CIS) and all the cells in squamous cell carcinomas (SCC) were examined in the same esophageal cancer specimens (n=48) which provided a model reflecting the process of esophageal carcinogenesis. Results: The positive rate of IHC staining was 87. 5% for NC, 95.3% for HC, 55.9% for DC (grade Ⅰ: 73.9%, grade Ⅱ: 47.4%, grade Ⅲ: 41.2%),36.4% for CIS and 45.8% for SCC. The positive rate of GST-π mRNA expression was 81.2% for NC, 94.4% for HC, 61.9% for DC (grade Ⅰ: 76.5%, grade Ⅱ: 61.5%,grade Ⅲ: 41.7%), 44.4% for CIS and 83.3% for grade ⅠSCC, 30.0% for grade Ⅱ SCC and 0% for grade ⅢSCC. There was no statistically significant difference in GST-π expression at the mRNA and the protein level.Conclusion: There is a decreasing tendency of GST-πexpression from dysplasia to CIS and SCC. The decrease in GST-π expression is an early event in esophageal carcinogenesis.

  1. Iron:An emerging factor in colorectal carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    Anita; CG; Chua; Borut; Klopcic; Ian; C; Lawrance; John; K; Olynyk; Debbie; Trinder

    2010-01-01

    The carcinogenic potential of iron in colorectal cancer(CRC) is not fully understood.Iron is able to undergo reduction and oxidation,making it important in many physiological processes.This inherent redox property of iron,however,also renders it toxic when it is present in excess.Iron-mediated generation of reactive oxygen species via the Fenton reaction,if uncontrolled,may lead to cell damage as a result of lipid peroxidation and oxidative DNA and protein damage.This may promote carcinogenesis through incr...

  2. Carcinogenesis related to intense pulsed light and UV exposure

    DEFF Research Database (Denmark)

    Hedelund, L; Lerche, C; Wulf, H C;

    2006-01-01

    This study examines whether intense pulsed light (IPL) treatment has a carcinogenic potential itself or may influence ultraviolet (UV)-induced carcinogenesis. Secondly, it evaluates whether UV exposure may influence IPL-induced side effects. Hairless, lightly pigmented mice (n=144) received three...... observation period. Side effects were evaluated clinically. No tumors appeared in untreated control mice or in just IPL-treated mice. Skin tumors developed in UV-exposed mice independently of IPL treatments. The time it took for 50% of the mice to first develop skin tumor ranged from 47 to 49 weeks...

  3. Contribution of bone marrow derived cells to pancreatic carcinogenesis

    Directory of Open Access Journals (Sweden)

    Christopher J Scarlett

    2013-03-01

    Full Text Available Pancreatic cancer is a complex, aggressive and heterogeneous malignancy driven by the multifaceted interactions within the tumor microenvironment. While it is known that the tumor microenvironment accommodates many cell types, each playing a key role in tumorigenesis, the major source of these stromal cells is not well understood. This review examines the contribution of bone marrow-derived cells (BMDC to pancreatic carcinogenesis, with respect to their role in constituting the tumor microenvironment. In particular, their role in supporting fibrosis, immunosuppression and neovascularisation will be discussed.

  4. Insights into the field carcinogenesis of ovarian cancer based on the nanocytology of endocervical and endometrial epithelial cells.

    Science.gov (United States)

    Damania, Dhwanil; Roy, Hemant K; Kunte, Dhananja; Hurteau, Jean A; Subramanian, Hariharan; Cherkezyan, Lusik; Krosnjar, Nela; Shah, Maitri; Backman, Vadim

    2013-09-01

    Ovarian cancer ranks fifth in cancer fatalities among American women. Although curable at early stages with surgery, most women are diagnosed with symptoms of late-stage metastatic disease. Moreover, none of the current diagnostic techniques are clinically recommended for at-risk women as they preferentially target low-grade tumors (which do not affect longevity) and fail to capture early signatures of more lethal serous tumors which originate in the fimbrae region of the fallopian tubes. Hence, the early detection of ovarian cancer is challenging given the current strategy. Recently, our group has developed a novel optical imaging technique, partial wave spectroscopic (PWS) microscopy, that can quantify the nanoscale macromolecular density fluctuations within biological cells via a biomarker, disorder strength (Ld ). Using the concept of field carcinogenesis, we propose a method of detecting ovarian cancer by PWS assessment of endometrial and endocervical columnar cells. The study includes 26 patients (controls = 15, cancer = 11) for endometrium and 23 (controls = 13, cancer = 10) for endocervix. Our results highlight a significant increase in Ld (% fold-increase > 50%, p-value < 0.05) for columnar epithelial cells obtained from cancer patients compared to controls for both endocervix and endometrium. Overall, the quantification of field carcinogenic events in the endometrium and the novel observation of its extension to the cervix are unique findings in the understanding of ovarian field carcinogenesis. We further show independent validation of the presence of cervical field carcinogenesis with micro-RNA expression data.

  5. Immobilization and characterization of a crude preparation of Escherichia coli trehalase: A laboratory exercise that integrates concepts of enzymology and molecular biology

    Directory of Open Access Journals (Sweden)

    A. S. Martins

    2009-05-01

    Full Text Available This paper  presents  a laboratory exercise for teaching  enzyme technology through  an  approach that integrates concepts of enzymology and molecular biology.  This  Laboratory Exercise  is based on the  extraction  of trehalase (EC 3.21.28 from a Escherichia coli  strain Mph2 (carrying the plasmid pTRE11 that harbors the gene TreA+ and immobilization of the enzyme on chitin. Therefore, the students  participate in bacterium cultivation, protein extraction from  E.coli  periplasmic space, preparation of chitin particles and enzyme immobilization.  Trehalase  was chosen because it  can be easily released by osmotic shock and it is not necessary to purify  it  from the osmotic shock fluid (OSF because  it is free of any other glycosidase. This lab exercise also teaches how to determine the kinetic parameters (Michaelis constant- Km and maximum velocity- Vm for free and immobilized enzymes.  It is obvious that the determination of kinetic parameters using the Michaelis-Menten model is not a novelty.  Nevertheless, an experimental class that includes the comparison of these parameters for free and immobilized enzymes, using the students´ own experimental data, would be extremely useful for teaching the subject. The students can identify and compare these parameters, as well  as discuss the differences and similarities among them. This discussion points towards issues such as  enzyme  conformation and structural rigidity related to changes in kinetic parameters mainly Km.  This Laboratory Exercise  was designed for graduate students that have a good background in Biochemistry and have joined courses involving either Enzymology or Enzyme Technology.

  6. Gene and genon concept: coding versus regulation. A conceptual and information-theoretic analysis of genetic storage and expression in the light of modern molecular biology.

    Science.gov (United States)

    Scherrer, Klaus; Jost, Jürgen

    2007-10-01

    We analyse here the definition of the gene in order to distinguish, on the basis of modern insight in molecular biology, what the gene is coding for, namely a specific polypeptide, and how its expression is realized and controlled. Before the coding role of the DNA was discovered, a gene was identified with a specific phenotypic trait, from Mendel through Morgan up to Benzer. Subsequently, however, molecular biologists ventured to define a gene at the level of the DNA sequence in terms of coding. As is becoming ever more evident, the relations between information stored at DNA level and functional products are very intricate, and the regulatory aspects are as important and essential as the information coding for products. This approach led, thus, to a conceptual hybrid that confused coding, regulation and functional aspects. In this essay, we develop a definition of the gene that once again starts from the functional aspect. A cellular function can be represented by a polypeptide or an RNA. In the case of the polypeptide, its biochemical identity is determined by the mRNA prior to translation, and that is where we locate the gene. The steps from specific, but possibly separated sequence fragments at DNA level to that final mRNA then can be analysed in terms of regulation. For that purpose, we coin the new term "genon". In that manner, we can clearly separate product and regulative information while keeping the fundamental relation between coding and function without the need to introduce a conceptual hybrid. In mRNA, the program regulating the expression of a gene is superimposed onto and added to the coding sequence in cis - we call it the genon. The complementary external control of a given mRNA by trans-acting factors is incorporated in its transgenon. A consequence of this definition is that, in eukaryotes, the gene is, in most cases, not yet present at DNA level. Rather, it is assembled by RNA processing, including differential splicing, from various pieces

  7. Effect of the electronic and physicochemical parameters on the carcinogenesis activity of some sulfa drugs using QSAR analysis based on genetic-MLR and genetic-PLS.

    Science.gov (United States)

    Deeb, Omar; Hemmateenejad, Bahram; Jaber, Amal; Garduno-Juarez, R; Miri, Ramin

    2007-05-01

    A quantitative structure activity relationship study has been applied to a data set of 18 sulfa drugs with carcinogenesis activity. Semi-empirical quantum chemical calculation (AM1 method) was used to find the optimum 3D geometry of the studied molecules. Two types of molecular descriptors including chemical and electronic was used to derive a quantitative relation between the carcinogenesis activity and structural properties. Two multi-parametric equations with good statistical qualities were obtained using genetic algorithms multiple linear regression (GA-MLR) methods. In addition, genetic algorithm-partial least squares (GA-PLS) regression was used to model the structure-activity relationships, more accurately. The results confirmed the superiority of the results obtained by GA-PLS relative to GA-MLR. The significant effect of the HOMO energy on the carcinogenic activity was explained in the context of the shape of this orbital.

  8. Thrombospondin-1 in a Murine Model of Colorectal Carcinogenesis.

    Directory of Open Access Journals (Sweden)

    Zenaida P Lopez-Dee

    Full Text Available Colorectal Cancer (CRC is one of the late complications observed in patients suffering from inflammatory bowel diseases (IBD. Carcinogenesis is promoted by persistent chronic inflammation occurring in IBD. Understanding the mechanisms involved is essential in order to ameliorate inflammation and prevent CRC. Thrombospondin 1 (TSP-1 is a multidomain glycoprotein with important roles in angiogenesis. The effects of TSP-1 in colonic tumor formation and growth were analyzed in a model of inflammation-induced carcinogenesis. WT and TSP-1 deficient mice (TSP-1-/- of the C57BL/6 strain received a single injection of azoxymethane (AOM and multiple cycles of dextran sodium sulfate (DSS to induce chronic inflammation-related cancers. Proliferation and angiogenesis were histologically analyzed in tumors. The intestinal transcriptome was also analyzed using a gene microarray approach. When the area containing tumors was compared with the entire colonic area of each mouse, the tumor burden was decreased in AOM/DSS-treated TSP-1-/- versus wild type (WT mice. However, these lesions displayed more angiogenesis and proliferation rates when compared with the WT tumors. AOM-DSS treatment of TSP-1-/- mice resulted in significant deregulation of genes involved in transcription, canonical Wnt signaling, transport, defense response, regulation of epithelial cell proliferation and metabolism. Microarray analyses of these tumors showed down-regulation of 18 microRNAs in TSP-1-/- tumors. These results contribute new insights on the controversial role of TSP-1 in cancer and offer a better understanding of the genetics and pathogenesis of CRC.

  9. Viral Carcinogenesis: Factors Inducing DNA Damage and Virus Integration

    Directory of Open Access Journals (Sweden)

    Yan Chen

    2014-10-01

    Full Text Available Viruses are the causative agents of 10%–15% of human cancers worldwide. The most common outcome for virus-induced reprogramming is genomic instability, including accumulation of mutations, aberrations and DNA damage. Although each virus has its own specific mechanism for promoting carcinogenesis, the majority of DNA oncogenic viruses encode oncogenes that transform infected cells, frequently by targeting p53 and pRB. In addition, integration of viral DNA into the human genome can also play an important role in promoting tumor development for several viruses, including HBV and HPV. Because viral integration requires the breakage of both the viral and the host DNA, the integration rate is believed to be linked to the levels of DNA damage. DNA damage can be caused by both endogenous and exogenous factors, including inflammation induced by either the virus itself or by co-infections with other agents, environmental agents and other factors. Typically, cancer develops years to decades following the initial infection. A better understanding of virus-mediated carcinogenesis, the networking of pathways involved in transformation and the relevant risk factors, particularly in those cases where tumorigenesis proceeds by way of virus integration, will help to suggest prophylactic and therapeutic strategies to reduce the risk of virus-mediated cancer.

  10. [THE ROLE OF ESTROGENS IN THE CARCINOGENESIS OF LUNG CANCER].

    Science.gov (United States)

    Uchikova, E; Uchikov, A; Dimitrakova, E; Uchikov, P

    2016-01-01

    Morbidity and mortality from lung cancer has dramatically increased in women as compared to men over the past few years. Historically, smoking has been considered the major risk factor for lung cancer regardless of gender. Several recent lines of evidence implicate gender differences in the observed differences in prevalence and histologic type which cannot be explained based on the carcinogenic action of nicotine. Several recent studies underscore the importance of reproductive and hormonal factors in the carcinogenesis of lung cancer Lung cancer morbidity and mortality in Bulgaria was 16.2/100000 women and 14.6/ 100000 women, resp. Lung cancer morbidity in Europe was 39/100000 women. Lung cancer is extremely sensitive to estrogens. The latter act directly or as effect modifiers for the relationship between smoking and lung cancer. Further research examining the relationship between serum estrogen levels and the estrogen receptor expression in normal and tumor lung tissue samples can help elucidate the importance of reproductive and hormonal (exogenous and endogenous) factors in the carcinogenesis of lung cancer.

  11. Langerhans Cells Facilitate UVB-induced Epidermal Carcinogenesis

    Science.gov (United States)

    Lewis, Julia M.; Bürgler, Christina D.; Freudzon, Marianna; Golubets, Kseniya; Gibson, Juliet F.; Filler, Renata B.; Girardi, Michael

    2015-01-01

    Ultraviolet B (UVB) light is considered the major environmental inducer of human keratinocyte DNA mutations, including within the tumor-suppressor gene p53, and chronic exposure is associated with cutaneous squamous cell carcinoma (SCC) formation. Langerhans cells (LC) comprise a dendritic network within the suprabasilar epidermis, yet the role of LC in UVB-induced carcinogenesis is largely unknown. Herein, we show that LC-intact epidermis develops UVB-induced tumors more readily than LC-deficient epidermis. While levels of epidermal cyclopyrimidine dimers (CPD) following acute UVB exposure are equivalent in the presence or absence of LC, chronic UVB-induced p53 mutant clonal islands expand more readily in association with LC which remain largely intact and are preferentially found in proximity to the expanding mutant keratinocyte populations. The observed LC facilitation of mutant p53 clonal expansion is completely αβ and γδ T-cell independent, and is associated with increased intraepidermal expression of interleukin (IL)-22 and the presence of group 3 innate lymphoid cells (ILC3). These data demonstrate that LC play a key role in UVB-induced cutaneous carcinogenesis, and suggest that LC locally stimulate keratinocyte proliferation and innate immune cells that provoke tumor outgrowth. PMID:26053049

  12. Transcriptional regulation of cadherins during development and carcinogenesis.

    Science.gov (United States)

    Peinado, Héctor; Portillo, Francisco; Cano, Amparo

    2004-01-01

    The cadherin superfamily of Ca(2+)-dependent homophilic adhesion molecules plays a critical role in regulating cell-to-cell interactions. During development, the expression of different cadherins is highly dynamic, since they are associated with the morphogenesis, establishment and/or maintenance of different tissues. Alterations in cadherin expression or function occur frequently during carcinogenesis, such as the loss of the epithelial cadherin (E-cadherin) and/or the aberrant expression of other cadherins. Indeed, the aberrant expression of cadherins has been detected during carcinoma invasion, a process which is reminiscent of the epithelial-mesenchymal transition (EMT) so important in many critical developmental processes. The functional regulation of cadherins can occur at many different levels, from transcriptional regulation to the control of the strength of the cadherin-mediated cell-cell interaction. In this review, we will focus on the transcriptional control of cadherin expression, both in development and carcinogenesis, paying particular attention to the regulation of E-cadherin given its proposed role as a suppressor of invasion. We will discuss the main genetic and epigenetic mechanisms involved in down-regulating E-cadherin expression, and we will analyse the mechanisms involved in regulating EMT, in an attempt to elucidate which elements are common to this process in both physiological and pathological situations.

  13. Field cancerization in mammary carcinogenesis - Implications for prevention and treatment of breast cancer.

    Science.gov (United States)

    Rivenbark, Ashley G; Coleman, William B

    2012-12-01

    The natural history of breast cancer unfolds with the development of ductal carcinoma in situ (DCIS) in normal breast tissue, and evolution of this pre-invasive neoplasm into invasive cancer. The mechanisms that drive these processes are poorly understood, but evidence from the literature suggests that mammary carcinogenesis may occur through the process of field cancerization. Clinical observations are consistent with the idea that (i) DCIS may arise in a field of altered breast epithelium, (ii) narrow surgical margins do not remove the entire altered field (contributing to recurrence and/or disease progression), and (iii) whole-breast radiation therapy is effective in elimination of the residual field of altered cells adjacent to the resected DCIS. Molecular studies suggest that the field of altered breast epithelial cells may carry cancer-promoting genetic mutations (or other molecular alterations) or cancer promoting epimutations (oncogenic alterations in the epigenome). In fact, most breast cancers develop through a succession of molecular events involving both genetic mutations and epimutations. Hence, in hereditary forms of breast cancer, the altered field reflects the entire breast tissue which is composed of cells with a predisposing molecular lesion (such as a BRCA1 mutation). In the example of a BRCA1-mutant patient, it is evident that local resection of a DCIS lesion or localized but invasive cancer will not result in elimination of the altered field. In sporadic breast cancer patients, the mechanistic basis for the altered field may not be so easily recognized. Nonetheless, identification of the nature of field cancerization in a given patient may guide clinical intervention. Thus, patients with DCIS that develops in response to an epigenetic lesion (such as a hypermethylation defect affecting the expression of tumor suppressor genes) might be treated with epigenetic therapy to normalize the altered field and reduce the risk of secondary occurrence of

  14. Effect of luteolin on glycoproteins metabolism in 1, 2-dimethylhydrazine induced experimental colon carcinogenesis

    Directory of Open Access Journals (Sweden)

    Manju Vaiyapuri

    2008-12-01

    carcinogenesis. Thus, the present study indicates that luteolin has protected the cell surface and maintained the structural integrity of the cell membranes during DMH induced colon carcinogenesis. Keywords: Colon cancer, 1, 2-dimethylhydrazine, luteolin, glycoproteins Received: 23 January 2009 / Received in revised form: 17 February 2009, Accepted: 28 February 2009, Published online: 3 March 2009

  15. Molecular Biology and Prevention of Endometrial Cancer

    Science.gov (United States)

    2009-07-01

    of the oral contraceptive pill (OCP). Project 1: Objectives completed and data previously submitted with 2004 report. Data published this past year...molecular aberrations associated with endometrial carcinogenesis and the biologic mechanisms underlying the protective effect of oral contraceptive (OC...not been altered appreciably. Despite the known protective effect of oral contraceptives , little has been learned regarding the underlying mechanism

  16. Low-molecular compounds of erythrocytes

    Directory of Open Access Journals (Sweden)

    O. O. Sorochan

    2006-01-01

    Full Text Available Glucose and free amino acids levels in rats’ blood plasma and erythrocytes hemolysate under carcinoma Geuren Т8 development as well as after introduction of Rhenium (III and сys-Platinum compounds were studied. The complex Rhenium (III compounds with organic ligands act as antioxidant and normalize the concentration of low-molecular compounds in erythrocytes under the carcinogenesis.

  17. The CK1 family: contribution to cellular stress response and its role in carcinogenesis

    Directory of Open Access Journals (Sweden)

    Uwe eKnippschild

    2014-05-01

    Full Text Available Members of the highly conserved and ubiquitously expressed pleiotropic CK1 family play major regulatory roles in many cellular processes including DNA-processing and repair, proliferation, cytoskeleton dynamics, vesicular trafficking, apoptosis, and cell differentiation. As a consequence of cellular stress conditions, interaction of CK1 with the mitotic spindle is manifold increased pointing to regulatory functions at the mitotic checkpoint. Furthermore, CK1 is able to alter the activity of key regulatory proteins and signal integration molecules and is tightly connected to the regulation of β-catenin, p53- and MDM2-specific functions and degradation. Considering the importance of CK1 for accurate cell division and regulation of tumor suppressor functions it is not surprising that mutations and alterations in the expression and/or activity of CK1 isoforms are often detected in various tumor entities including cancer of the kidney, choriocarcinomas, breast carcinomas, oral cancer, adenocarcinomas of the pancreas, and ovarian cancer. Therefore, effort has enormously increased (i to understand the regulation of CK1 and its involvement in tumorigenesis- and tumor progression-related signal transduction pathways and (ii to develop CK1-specific inhibitors for the use in personalized therapy concepts. In this review we summarize the current knowledge regarding the regulation, functions, and interactions of CK1 family members with cellular proteins playing central roles in cellular stress-responses and carcinogenesis.

  18. DNA interstrand cross-link induced by estrogens as well as their complete and synergic carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The estrogens show negative activity in Ames test, but estrodiol and diethylstilbestrol in estrogens both are carcinogens based upon animal experiments and epidemiological investigation. It is concluded from the di-region theory, a mechanism conception put forward by one of the present authors, that the carcinogenesis of estrogens is switched on by the covalent cross-link between complementary DNA bases induced by them. We verified for the first time by the DNA alkaline elution method that both estrodiol and diethylstilbestrol cause covalent cross-link between DNA-protein and DNA interstrands after metabolic activation with dosage correlation, but neither the non-carcinogens cholesterol nor pyrene can lead to these sorts of cross-link in the same condition. It has been known that there is a synergetic effect between estrogen and pollution of polycyclic aromatic hydrocarbons. Although non-carcinogenic pyrene alone cannot induce cross-link, its addition with equal molar quantity to estrodiol culture causes synergically the total and DNA interstrand cross-link ratios to be respectively four and three times more than the ones in the cultivation with estrodiol only. It is shown that not only the estrodiol set off the formation of pyrene bi-radicals, but also the pyrene radicals arouse conversely the production of estrodiol bi-radicals.

  19. HSP-molecular chaperones in cancer biogenesis and tumor therapy: an overview.

    Science.gov (United States)

    Rappa, Francesca; Farina, Felicia; Zummo, Giovanni; David, Sabrina; Campanella, Claudia; Carini, Francesco; Tomasello, Giovanni; Damiani, Provvidenza; Cappello, Francesco; DE Macario, Everly Conway; Macario, Alberto J L

    2012-12-01

    Molecular chaperones, many of which are heat-shock proteins (HSPs), are an important class of molecules with various functions. Pathological conditions in which chaperones become etiological and/or pathogenic factors are called chaperonopathies, and are classified into by defect, by excess, and by 'mistake'. In the latter case, the chaperone is structurally and functionally normal but participates in pathways that favor disease, although in some cases the chaperone may have post-translational modifications that may lead it to change its location and function and, thus, to become pathogenic. For example, HSP-chaperones are involved in carcinogenesis in various ways, so that some forms of cancer may be considered 'chaperonopathies by mistake'. This concept suggests new strategies for anticancer therapy (chaperonotherapy), in which the primary targets or therapeutic agents are chaperones. Chaperonotherapy consists of the utilization of HSP-chaperones for treating chaperonopathies, including cancer. Negative chaperonotherapy is aimed at eliminating or blocking the action of chaperones that favor carcinogenesis or other diseases, whereas positive chaperonotherapy uses chaperones, genes or proteins, to fight against diseases, such as cancer, by stimulating the immune system or the cellular defenses against stress.

  20. Growth-related alterations during liver carcinogenesis: Effect of promoters

    Energy Technology Data Exchange (ETDEWEB)

    Seglen, P.O.; Gerlyng, P. (Norwegian Radium Hospital, Oslo (Norway))

    1990-08-01

    Bromodeoxyuridine labeling of DNA, binuclearity counting, and flow cytometric analysis of isolated hepatocytes and hepatocyte nuclei has been used to assess heptocellular growth patterns related to liver carcinogenesis. Three growth patterns can be distinguished. Mononucleating growth is observed during liver regeneration and after treatment with the tumor promoter 2-acetylaminofluorene (2-AAF) and its analogue 4-AAF. In this growth mode binucleation does not occur, resulting in a decrease in the fraction of binucleated cells. Binucleating growth is observed during normal liver development and after treatment with compounds such as phenobarbital, characterized by progressive polyploidization and maintenance of a binucleated cell fraction. Diploid growth is the growth pattern of neoplastic liver hepatocytes. Most of the cells in neoplastic lesions (foci, nodules, and carcinomas) are diploid, in contrast to the normal liver. Diploid tumor cells have a much higher proliferative activity than tetraploid tumor cells, suggesting that the latter may posses a limited growth potential that makes abrogation of binucleation proliferatively advantageous.

  1. Recent advances in the study of HPV-associated carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    Liyan; Jin; Zhi-Xiang; Xu

    2015-01-01

    Human papillomaviruses(HPVs) cause virtually all cervical cancers, the second leading cause of death by cancer among women, as well as other anogenital cancers and a subset of head and neck cancers. Approximately half of women, who develop cervical cancer die from it. Despite the optimism that has accompanied the introduction of prophylactic vaccines to prevent some HPV infections, the relatively modest uptake of the vaccine, especially in the developing world, and the very high fraction of men and women who are already infected, means that HPV-associated disease will remain as a significant public health problem for decades. In this review, we summarize some recent findings on HPV-associated carcinogenesis, such as mi RNAs in HPV-associated cancers, implication of stem cells in the biology and therapy of HPV-positive cancers, HPV vaccines, targeted therapy of cervical cancer, and drug treatment for HPV-induced intraepithelial neoplasias.

  2. Translesion Synthesis Polymerases in the Prevention and Promotion of Carcinogenesis

    Directory of Open Access Journals (Sweden)

    L. Jay Stallons

    2010-01-01

    Full Text Available A critical step in the transformation of cells to the malignant state of cancer is the induction of mutations in the DNA of cells damaged by genotoxic agents. Translesion DNA synthesis (TLS is the process by which cells copy DNA containing unrepaired damage that blocks progression of the replication fork. The DNA polymerases that catalyze TLS in mammals have been the topic of intense investigation over the last decade. DNA polymerase η (Pol η is best understood and is active in error-free bypass of UV-induced DNA damage. The other TLS polymerases (Pol ι, Pol κ, REV1, and Pol ζ have been studied extensively in vitro, but their in vivo role is only now being investigated using knockout mouse models of carcinogenesis. This paper will focus on the studies of mice and humans with altered expression of TLS polymerases and the effects on cancer induced by environmental agents.

  3. Thymus in experimental carcinogenesis of the prostate gland.

    Science.gov (United States)

    Borodin, Yu I; Lomshakov, A A; Astashov, V V; Kazakov, O V; Mayorov, A P; Larionov, P M

    2014-10-01

    We studied structural changes in the prostate gland, thymus, and lymph nodes in CBA mice after transplantation of Ehrlich ascites tumor cells into the prostate gland. On experimental day 5, the number of blood and lymph vessels decreased in the gland; the percentage of connective tissue elements and glandular tissue and the number of immunoblasts in the thymus increased. On day 18, the number of blood vessels in the tumor decreased; the width of the cortex and glandular tissue increased in the thymus, while the number of immunoblasts was reduced. On day 28, tumor infiltration and increased number of lymphatic vessels in its stroma were observed; parenchyma was reduced, and the area of the connective tissue increased in the thymus. These structural changes indicated the development of accidental involution of the thymus during carcinogenesis of the prostate.

  4. Pathogenesis and biomarkers of carcinogenesis in ulcerative colitis

    DEFF Research Database (Denmark)

    Thorsteinsdottir, Sigrun; Gudjonsson, Thorkell; Nielsen, Ole Haagen

    2011-01-01

    One of the most serious complications of ulcerative colitis is the development of colorectal cancer. Screening patients with ulcerative colitis by standard histological examination of random intestinal biopsy samples might be inefficient as a method of cancer surveillance. This Review focuses...... on the current understanding of the pathogenesis of ulcerative colitis-associated colorectal cancer and how this knowledge can be transferred into patient management to assist clinicians and pathologists in identifying patients with ulcerative colitis who have an increased risk of colorectal cancer. Inflammation....... Although progress has been made in the understanding of inflammation-driven carcinogenesis, markers based on these findings possess insufficient sensitivity or specificity to be usable as reliable biomarkers for risk of colorectal cancer development in patients with ulcerative colitis. However, screening...

  5. Mushroom Ganoderma lucidum prevents colitis-associated carcinogenesis in mice.

    Directory of Open Access Journals (Sweden)

    Daniel Sliva

    Full Text Available BACKGROUND: Epidemiological studies suggest that mushroom intake is inversely correlated with gastric, gastrointestinal and breast cancers. We have recently demonstrated anticancer and anti-inflammatory activity of triterpene extract isolated from mushroom Ganoderma lucidum (GLT. The aim of the present study was to evaluate whether GLT prevents colitis-associated carcinogenesis in mice. METHODS/PRINCIPAL FINDINGS: Colon carcinogenesis was induced by the food-borne carcinogen (2-Amino-1-methyl-6-phenylimidazol[4,5-b]pyridine [PhIP] and inflammation (dextran sodium sulfate [DSS] in mice. Mice were treated with 0, 100, 300 and 500 mg GLT/kg of body weight 3 times per week for 4 months. Cell proliferation, expression of cyclin D1 and COX-2 and macrophage infiltration was assessed by immunohistochemistry. The effect of GLT on XRE/AhR, PXR and rPXR was evaluated by the reporter gene assays. Expression of metabolizing enzymes CYP1A2, CYP3A1 and CYP3A4 in colon tissue was determined by immunohistochemistry. GLT treatment significantly suppressed focal hyperplasia, aberrant crypt foci (ACF formation and tumor formation in mice exposed to PhIP/DSS. The anti-proliferative effects of GLT were further confirmed by the decreased staining with Ki-67 in colon tissues. PhIP/DSS-induced colon inflammation was demonstrated by the significant shortening of the large intestine and macrophage infiltrations, whereas GLT treatment prevented the shortening of colon lengths, and reduced infiltration of macrophages in colon tissue. GLT treatment also significantly down-regulated PhIP/DSS-dependent expression of cyclin D1, COX-2, CYP1A2 and CYP3A4 in colon tissue. CONCLUSIONS: Our data suggest that GLT could be considered as an alternative dietary approach for the prevention of colitis-associated cancer.

  6. Differential network analysis reveals dysfunctional regulatory networks in gastric carcinogenesis.

    Science.gov (United States)

    Cao, Mu-Shui; Liu, Bing-Ya; Dai, Wen-Tao; Zhou, Wei-Xin; Li, Yi-Xue; Li, Yuan-Yuan

    2015-01-01

    Gastric Carcinoma is one of the most common cancers in the world. A large number of differentially expressed genes have been identified as being associated with gastric cancer progression, however, little is known about the underlying regulatory mechanisms. To address this problem, we developed a differential networking approach that is characterized by including a nascent methodology, differential coexpression analysis (DCEA), and two novel quantitative methods for differential regulation analysis. We first applied DCEA to a gene expression dataset of gastric normal mucosa, adenoma and carcinoma samples to identify gene interconnection changes during cancer progression, based on which we inferred normal, adenoma, and carcinoma-specific gene regulation networks by using linear regression model. It was observed that cancer genes and drug targets were enriched in each network. To investigate the dynamic changes of gene regulation during carcinogenesis, we then designed two quantitative methods to prioritize differentially regulated genes (DRGs) and gene pairs or links (DRLs) between adjacent stages. It was found that known cancer genes and drug targets are significantly higher ranked. The top 4% normal vs. adenoma DRGs (36 genes) and top 6% adenoma vs. carcinoma DRGs (56 genes) proved to be worthy of further investigation to explore their association with gastric cancer. Out of the 16 DRGs involved in two top-10 DRG lists of normal vs. adenoma and adenoma vs. carcinoma comparisons, 15 have been reported to be gastric cancer or cancer related. Based on our inferred differential networking information and known signaling pathways, we generated testable hypotheses on the roles of GATA6, ESRRG and their signaling pathways in gastric carcinogenesis. Compared with established approaches which build genome-scale GRNs, or sub-networks around differentially expressed genes, the present one proved to be better at enriching cancer genes and drug targets, and prioritizing

  7. Protein expression analysis of inflammation-related colon carcinogenesis

    Directory of Open Access Journals (Sweden)

    Yasui Yumiko

    2009-01-01

    Full Text Available Background: Chronic inflammation is a risk factor for colorectal cancer (CRC development. The aim of this study was to determine the differences in protein expression between CRC and the surrounding nontumorous colonic tissues in the mice that received azoxymethane (AOM and dextran sodium sulfate (DSS using a proteomic analysis. Materials and Methods: Male ICR mice were given a single intraperitoneal injection of AOM (10 mg/kg body weight, followed by 2% (w/v DSS in their drinking water for seven days, starting one week after the AOM injection. Colonic adenocarcinoma developed after 20 weeks and a proteomics analysis based on two-dimensional gel electrophoresis and ultraflex TOF/TOF mass spectrometry was conducted in the cancerous and nontumorous tissue specimens. Results: The proteomic analysis revealed 21 differentially expressed proteins in the cancerous tissues in comparison to the nontumorous tissues. There were five markedly increased proteins (beta-tropomyosin, tropomyosin 1 alpha isoform b, S100 calcium binding protein A9, and an unknown protein and 16 markedly decreased proteins (Car1 proteins, selenium-binding protein 1, HMG-CoA synthase, thioredoxin 1, 1 Cys peroxiredoxin protein 2, Fcgbp protein, Cytochrome c oxidase, subunit Va, ETHE1 protein, and 7 unknown proteins. Conclusions: There were 21 differentially expressed proteins in the cancerous tissues of the mice that received AOM and DSS. Their functions include metabolism, the antioxidant system, oxidative stress, mucin production, and inflammation. These findings may provide new insights into the mechanisms of inflammation-related colon carcinogenesis and the establishment of novel therapies and preventative strategies to treat carcinogenesis in the inflamed colon.

  8. The Role of Macrophage Migration Inhibitory Factor (MIF) in Ultraviolet Radiation-Induced Carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Tadamichi [Department of Dermatology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Sugitani, 930-0194, Toyama (Japan)

    2010-08-09

    Ultraviolet (UV) radiation is the most common cause of physical injury to the skin due to environmental damage, and UV exposure substantially increases the risk of actinic damage to the skin. The inflammatory changes induced by acute UV exposure include erythema (sunburn) of the skin, while chronic exposure to solar UV radiation causes photo-aging, immunosuppression, and ultimately, carcinogenesis of the skin. After skin damage by UV radiation, the cells are known to secrete many cytokines, including interleukin (IL)-1, IL-6, tumor necrosis factor (TNF)-α. and macrophage migration inhibitory factor (MIF). MIF was originally identified as a lymphokine that concentrates macrophages at inflammatory loci, and is known to be a potent activator of macrophages in vivo. MIF is considered to play an important role in cell-mediated immunity. Since the molecular cloning of MIF cDNA, MIF has been re-evaluated as a proinflammatory cytokine and pituitary-derived hormone that potentiates endotoxemia. MIF is ubiquitously expressed in various tissues, including the skin. Recent studies have suggested a potentially broader role for MIF in growth regulation because of its ability to antagonize p53-mediated gene activation and apoptosis. This article reviews the latest findings on the roles of MIF with regard to UV-induced skin cancer.

  9. Doxycycline Promotes Carcinogenesis & Metastasis via Chronic Inflammatory Pathway: An In Vivo Approach.

    Directory of Open Access Journals (Sweden)

    Neha Nanda

    Full Text Available Doxycycline (DOX exhibits anti-inflammatory, anti-tumor, and pro-apoptotic activity and is being tested in clinical trials as a chemotherapeutic agent for several cancers, including colon cancer.In the current study, the chemotherapeutic activity of doxycycline was tested in a rat model of colon carcinogenesis, induced by colon specific cancer promoter, 1,2, dimethylhydrazine (DMH as well as study the effect of DOX-alone on a separate group of rats.Doxycycline administration in DMH-treated rats (DMH-DOX unexpectedly increased tumor multiplicity, stimulated progression of colonic tumor growth from adenomas to carcinomas and revealed metastasis in small intestine as determined by macroscopic and histopathological analysis. DOX-alone treatment showed markedly enhanced chronic inflammation and reactive hyperplasia, which was dependent upon the dose of doxycycline administered. Moreover, immunohistochemical analysis revealed evidence of inflammation and anti-apoptotic action of DOX by deregulation of various biomarkers.These results suggest that doxycycline caused chronic inflammation in colon, small intestine injury, enhanced the efficacy of DMH in tumor progression and provided a mechanistic link between doxycycline-induced chronic inflammation and tumorigenesis. Ongoing studies thus may need to focus on the molecular mechanisms of doxycycline action, which lead to its inflammatory and tumorigenic effects.

  10. Role of Free Radicals, Oxidative Stress and Xenobiotics in Carcinogenesis by Environmental Pollutants

    Directory of Open Access Journals (Sweden)

    Dibyajyoti Saha

    2014-09-01

    Full Text Available Carcinogenesis by many small molecular weight chemicals involves either a direct action of the chemical on cellular DNA or metabolism of the parent chemical to an active or ultimate form, which can than react with cellular DNA to produce a permanent chemical change in a DNA structure. A free radical is an atom or molecule that has one or more unpaired electron(s. These are highly reactive species capable of wide spread, indiscriminate oxidation and per oxidation of proteins, lipids and DNA which can lead to significant cellular damage and even tissue and/or organ failure. . Oxidative stress is a leading cause to damage cells by oxidation. The rate at which oxidative damage is induced (input and the rate at which it is efficiently repaired and removed (output. Xenobiotics are a compound that is foreign to the body. Xenobiotics can produce a variety of biological effects, including pharmacologic responses, toxicity, genes, immunologic reactions and cancer. Oxidative stress is a leading cause to damage cells by oxidation. The rate at which oxidative damage is induced (input and the rate at which it is efficiently repaired and removed (output. This communication highlights the role of carcinogens as environmental pollutants with the possible mechanism of free radicals, oxidative stress and xenobiotics.

  11. Identification of a nuclear protein, LRRC42, involved in lung carcinogenesis.

    Science.gov (United States)

    Fujitomo, Takashi; Daigo, Yataro; Matsuda, Koichi; Ueda, Koji; Nakamura, Yusuke

    2014-07-01

    On the basis of the gene expression profiles of 120 lung cancer cases using a cDNA microarray containing 27,648 genes or expressed sequence tags (ESTs), we identified LRRC42 (Leucine-rich repeat containing 42) to be significantly upregulated in the majority of lung cancers. Northern blot analysis demonstrated that LRRC42 was expressed only in testis among normal tissues examined. Knockdown of LRRC42 expression by siRNA against LRRC42 significantly suppressed the growth of lung cancer cells. On the other hand, stable induction of LRRC42 expression significantly promoted cell growth. LRRC42, which was found to localize in the nucleus of mammalian cells, is likely to interact with and stabilize GATAD2B (GATA zinc finger domain-containing 2B) and MBD3 (Methyl-CpG-binding domain protein 3) proteins that could contribute to lung cancer cell proliferation partly through the regulation of p21Waf1/Cip1. Our findings suggest that LRRC42 overexpression as well as its interaction with LRRC42-GATAD2B might play essential roles in lung carcinogenesis, and be a promising molecular target for lung cancer therapy.

  12. Punica granatum and its therapeutic implications on breast carcinogenesis: A review.

    Science.gov (United States)

    Vini, Ravindran; Sreeja, Sreeharshan

    2015-01-01

    Punica granatum has a recorded history of pharmacological properties which can be attributed to its rich reservoir of phytochemicals. Investigations in recent years have established its tremendous potential as an antitumorogenic agent against various cancers including breast cancer, which is the second leading cause of cancer-related deaths in women. The plausible role of Punica as a therapeutic agent, as an adjuvant in chemotherapy, and its dietary implications as chemopreventive agent in breast cancer have been explored. Mechanistic studies have revealed that Punica extracts and its components, individually or in combination, can modulate and target key proteins and genes involved in breast cancer. Our earlier finding also demonstrated the role of methanolic extract of pomegranate pericarp in reducing proliferation in breast cancer by binding to estrogen receptor at the same time not affecting uterine weight unlike estradiol or tamoxifen. This review analyses other plausible mechanisms of Punica in preventing the progression of breast cancer and how it can possibly be a therapeutic agent by acting at various steps of carcinogenesis including proliferation, invasion, migration, metastasis, angiogenesis, and inflammation via various molecular mechanisms.

  13. Boolean Network Model for Cancer Pathways: Predicting Carcinogenesis and Targeted Therapy Outcomes

    Science.gov (United States)

    Fumiã, Herman F.; Martins, Marcelo L.

    2013-01-01

    A Boolean dynamical system integrating the main signaling pathways involved in cancer is constructed based on the currently known protein-protein interaction network. This system exhibits stationary protein activation patterns – attractors – dependent on the cell's microenvironment. These dynamical attractors were determined through simulations and their stabilities against mutations were tested. In a higher hierarchical level, it was possible to group the network attractors into distinct cell phenotypes and determine driver mutations that promote phenotypic transitions. We find that driver nodes are not necessarily central in the network topology, but at least they are direct regulators of central components towards which converge or through which crosstalk distinct cancer signaling pathways. The predicted drivers are in agreement with those pointed out by diverse census of cancer genes recently performed for several human cancers. Furthermore, our results demonstrate that cell phenotypes can evolve towards full malignancy through distinct sequences of accumulated mutations. In particular, the network model supports routes of carcinogenesis known for some tumor types. Finally, the Boolean network model is employed to evaluate the outcome of molecularly targeted cancer therapies. The major find is that monotherapies were additive in their effects and that the association of targeted drugs is necessary for cancer eradication. PMID:23922675

  14. [Colorectal cancer (CCR): genetic and molecular alterations].

    Science.gov (United States)

    Juárez-Vázquez, Clara Ibet; Rosales-Reynoso, Mónica Alejandra

    2014-01-01

    The aim of this review is to present a genetic and molecular overview of colorectal carcinogenesis (sporadic and hereditary origin) as a multistage process, where there are a number of molecular mechanisms associated with the development of colorectal cancer and genomic instability that allows the accumulation of mutations in proto-oncogenes and tumor suppressor genes, chromosomal instability, and methylation and microsatellite instability, and the involvement of altered expression of microRNAs' prognosis factors.

  15. Rationale and design of the Japan molecular epidemiology for lung cancer study.

    Science.gov (United States)

    Kawaguchi, Tomoya; Ando, Masahiko; Ito, Norimasa; Isa, Shun-Ichi; Tamiya, Akihiro; Shimizu, Shigeki; Saka, Hideo; Kubo, Akihito; Koh, Yasuhiro; Matsumura, Akihide

    2013-09-01

    We present the rationale for the Japan Molecular Epidemiology for Lung Cancer study designed to elucidate molecular mechanisms of carcinogenesis in smokers and never-smokers with non-small-cell lung cancer. This prospective, ongoing, multicenter study is being conducted nationwide in Japan. Although there is no doubt that active smoking is the major cause of lung cancer, the contribution of other possible factors, including environmental tobacco or wood smoke, human papilloma virus, radon, occupational exposures, and genetic susceptibility, is highly likely, based on studies of never-smokers with non-small-cell lung cancer. Because of the predominance of women in the never-smoker subgroup, the role of female hormones in lung cancer development has also been considered. We hypothesize that driver mutations, which are critical for the development of lung cancer, are triggered by the environmental factors with or without the influence of the hormone. The SWOG-led intergroup molecular epidemiology study S0424 was conducted to focus on these issues by using a detailed questionnaire and specimen collection in statistically significant cohorts of smokers and never-smokers from both sexes. The Japan Molecular Epidemiology for Lung Cancer study follows and extends the S0424 molecular epidemiology concept in principle by using a similar approach that will facilitate future comparisons between the studies but with a greater focus on more recently defined driver mutations and broad genomic sequencing.

  16. The association between methylated CDKN2A and cervical carcinogenesis, and its diagnostic value in cervical cancer: a meta-analysis

    Directory of Open Access Journals (Sweden)

    Li J

    2016-08-01

    Full Text Available Jinyun Li,1,2,* Chongchang Zhou,1,* Haojie Zhou,3,* Tianlian Bao,1 Tengjiao Gao,1 Xiangling Jiang,1 Meng Ye1,2 1Department of Biochemistry and Molecular Biology, School of Medicine, Ningbo University, 2Department of Medical Oncology, Affiliated Hospital, Ningbo University, 3Department of Molecular Diagnosis, Ningbo Diagnostic Pathology Center, Ningbo, Zhejiang, People’s Republic of China *These authors are co-first authors of this work Background: Cervical cancer is the second deadliest gynecologic malignancy, characterized by apparently precancerous lesions and cervical intraepithelial neoplasia (CIN, and having a long course from the development of CIN to cervical cancer. Cyclin-dependent kinase inhibitor 2A (CDKN2A is a well-documented tumor suppressor gene and is commonly methylated in cervical cancer. However, the relationship between methylated CDKN2A and carcinogenesis in cervical cancer is inconsistent, and the diagnostic accuracy of methylated CDKN2A is underinvestigated. In this study, we attempted to quantify the association between CDKN2A methylation and the carcinogenesis of cervical cancer, and its diagnostic power.Methods: We systematically reviewed four electronic databases and identified 26 studies involving 1,490 cervical cancers, 1,291 CINs, and 964 controls. A pooled odds ratio (OR with corresponding 95% confidence intervals (95% CI was calculated to evaluate the association between methylated CDKN2A and the carcinogenesis of cervical cancer. Specificity, sensitivity, the area under the receiver operating characteristic curve, and the diagnostic odds ratio were computed to assess the effect of methylated CDKN2A in the diagnosis of cervical cancer.Results: Our results indicated an upward trend in the methylation frequency of CDKN2A in the carcinogenesis of cervical cancer (cancer vs control: OR =23.67, 95% CI =15.54–36.06; cancer vs CIN: OR =2.53, 95% CI =1.79–3.5; CIN vs control: OR =9.68, 95% CI =5.82–16.02. The

  17. ING Genes Work as Tumor Suppressor Genes in the Carcinogenesis of Head and Neck Squamous Cell Carcinoma.

    Science.gov (United States)

    Li, Xiaohan; Kikuchi, Keiji; Takano, Yasuo

    2011-01-01

    Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer in the world. The evolution and progression of HNSCC are considered to result from multiple stepwise alterations of cellular and molecular pathways in squamous epithelium. Recently, inhibitor of growth gene (ING) family consisting of five genes, ING1 to ING5, was identified as a new tumor suppressor gene family that was implicated in the downregulation of cell cycle and chromatin remodeling. In contrast, it has been shown that ING1 and ING2 play an oncogenic role in some cancers, this situation being similar to TGF-β. In HNSCC, the ING family has been reported to be downregulated, and ING translocation from the nucleus to the cytoplasm may be a critical event for carcinogenesis. In this paper, we describe our recent results and briefly summarize current knowledge regarding the biologic functions of ING in HNSCC.

  18. Alterations of C-MYC, NKX3.1, and E-cadherin expression in canine prostate carcinogenesis

    DEFF Research Database (Denmark)

    Fonseca-Alves, Carlos E; Rodrigues, Marcela M P; de Moura, Veridiana M B D;

    2013-01-01

    therapies. In humans, the PCa frequently exhibits mutations in the C-MYC and a reduced expression of the E-cadherin and NKX3.1 proteins. This study's objective was to evaluate the NKX3.1, C-MYC, and E-cadherin expression in the canine normal prostate, benign prostatic hyperplasia (BPH), proliferative......The dog (canis lupus familiaris) is the only other species besides humans that develop spontaneous prostatic carcinomas (PCa) at a high frequency. The canine model is primarily utilized for the study of the PCa molecular mechanisms and provides a natural animal model for the study of potential...... inflammatory atrophy (PIA) and PCa and to verify differences in expression and subcellular localization of these proteins in the prostatic carcinogenesis. A tissue microarray (TMA) slide was constructed, and immunohistochemistry with antibodies raised against C-MYC, NKX3.1, E-cadherin and p63 was performed...

  19. Concept theory

    DEFF Research Database (Denmark)

    Hjørland, Birger

    2009-01-01

      Concept theory is an extremely broad, interdisciplinary and complex field of research related to many deep fields with very long historical traditions without much consensus. However, information science and knowledge organization cannot avoid relating to theories of concepts. Knowledge...... organizing systems (e.g. classification systems, thesauri and ontologies) should be understood as systems basically organizing concepts and their semantic relations. The same is the case with information retrieval systems. Different theories of concepts have different implications for how to construe......, evaluate and use such systems. Based on "a post-Kuhnian view" of paradigms this paper put forward arguments that the best understanding and classification of theories of concepts is to view and classify them in accordance with epistemological theories (empiricism, rationalism, historicism and pragmatism...

  20. Relationship between Helicobacter pylori infection and gastric carcinogenesis in elderly patients

    Institute of Scientific and Technical Information of China (English)

    李文新

    2013-01-01

    Objective To explore the relationship between Helicobacter pylori (HP) infection and gastric carcinogenesis,and to investigate its mechanism.Methods Totally 333elderly patients with different degrees of gastric mucosal lesions in our hospital were selected.Patients were

  1. Senescence and apoptosis in carcinogenesis of cervical squamous carcinoma.

    Science.gov (United States)

    Feng, Wei; Xiao, Jianguo; Zhang, Zhihong; Rosen, Daniel G; Brown, Robert E; Liu, Jinsong; Duan, Xiuzhen

    2007-09-01

    Senescence and apoptosis are two key mechanisms that protect against cancer development. Many cell cycle regulators, such as p14(ARF), p15(INK4b) and p16(INK4a), are important in G1 cell cycle arrest and oncogene-induced senescence. The bcl-2 protein is one of the key components that control apoptosis, while the p53 protein plays key roles in both mechanisms. The genes of these key regulator proteins are often mutated or deleted in various malignancies. It is unknown how senescence and apoptosis are regulated in one of the most common tumors of the female genital tract, cervical squamous cell carcinoma (SCC). In this study the, expression of senescence, apoptosis and proliferation markers in normal cervical epithelium, cervical intraepithelial neoplasia (CIN) and SCC are characterized via immunohistochemical staining for p14(ARF), p15(INK4b), p16(INK4a), bcl-2, p53 and Ki-67 in tissue microarray blocks containing 20 samples each of normal cervix, moderate-to-severe cervical dysplasia (CIN II-III) and invasive SCC. Samples are derived from 60 total cases of cervical biopsies and cervical conizations. Results showed that the proliferation marker, Ki-67, is markedly increased, and the senescence markers, p15(INK4b), p16(INK4a) and p14(ARF) are overexpressed in both dysplasia and carcinoma. P53 immunostain is negative in all normal cervical tissue, and positive in dysplasia and carcinoma. Although the expression of bcl-2 is increased in dysplasia, this marker is negative in approximately half of SCC cases. These results suggest that some senescence pathways are activated and are still maintained in cervical dysplasia and carcinoma. However proliferation is increased and carcinogenesis is not thwarted, leading to eventual development of cervical cancer. Other mechanisms, such as those that account for the apparent overexpression of p53 and paradoxical loss of bcl-2 expression in some SCC cases, as well as additional senescence and apoptotic pathways, may play key roles

  2. Apoptotic cell death and its relationship to gastric carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    Ferda Bir; Nese Calli-Demirkan; A Cevik Tufan; Metin Akbulut; N Lale Satiroglu-Tufan

    2007-01-01

    AIM: To investigate the apoptotic process of cells within the intestinal metaplasia areas co-localizing with chronic gastritis and gastric carcinomas and to analyze the involvement of proteins regulating apoptosis in the process of intestinal metaplasia related gastric carcinogenesis.METHODS: Forty-two gastric carcinoma and seventeen chronic gastritis cases were included in this study. All cases were examined for the existence of intestinal metaplasia. Ten cases randomly selected from each group were processed for TUNEL assay. TUNEL positive cells within the intestinal metaplasia areas, colocalizing either to gastric carcinoma or chronic gastritis,were counted and converted to apoptotic indices.In addition, p53, bcl-2 and bax expression patterns within these tissues were analyzed on the basis of immunohistochemistry.RESULTS: Twenty-eight of the cases were intestinal and 14 of the cases were diffuse type adenocarcinomas.64% (27/42) of the gastric carcinoma cases had intestinal metaplasia. Intestinal metaplasia co-localized more with intestinal type carcinomas compared with diffuse type carcinomas [75% (21/28) vs 42% (6/14),respectively; P≤0.05]. The mean apoptotic index in tumor cells was 0.70±0.08. The mean apoptotic index in intestinal metaplasias co-localizing to tumors was significantly higher than that of intestinal metaplasias co-localizing to chronic gastritis (0.70±0.03 vs 0.09±0.01, respectively; P≤0.05). P53 positivity was not observed in areas of intestinal metaplasia adjacent to tumors or chronic gastritis. Intestinal metaplasia areas adjacent to tumors showed lower cytoplasmic bcl-2 positivity compared to intestinal metaplasia areas adjacent to chronic gastritis [55.5% (15/27) vs 70.5%(12/17), respectively]. On the other hand, intestinal metaplasia areas adjacent to tumors showed significantly higher cytoplasmic bax positivity compared to intestinal metaplasia areas adjacent to chronic gastritis [44.4%(12/27) vs 11.7% (2/17), respectively; P≤0

  3. Role of MicroRNAs in carcinogenesis that potential for biomarker of endometrial cancer

    OpenAIRE

    Widodo1); Djati, Muhammad Sasmito; Rifa'i, Muhaimin

    2016-01-01

    The non-invasive diagnostic tool for early detection of endometrial cancer still limited. The etiology of this disease is believed to be associated with disharmony hormone production. One predominant factor that regulate hormone production is microRNA (miRNAs). Some studies reported that miRNAs play a significant role in the process carcinogenesis. We have identified 12 of miRNAs that potentially have a role in controlling endometrial carcinogenesis pathways. Further analysis suggested that t...

  4. The diffuse endocrine system: from embryogenesis to carcinogenesis.

    Science.gov (United States)

    Montuenga, Luis M; Guembe, Laura; Burrell, M Angela; Bodegas, M Elena; Calvo, Alfonso; Sola, Jesús J; Sesma, Pilar; Villaro, Ana C

    2003-01-01

    In the present review we will summarise the current knowledge about the cells comprising the Diffuse Endocrine System (DES) in mammalian organs. We will describe the morphological, histochemical and functional traits of these cells in three major systems gastrointestinal, respiratory and prostatic. We will also focus on some aspects of their ontogeny and differentiation, as well as to their relevance in carcinogenesis, especially in neuroendocrine tumors. The first chapter describes the characteristics of DES cells and some of their specific biological and biochemical traits. The second chapter deals with DES in the gastrointestinal organs, with special reference to the new data on the differentiation mechanisms that leads to the appearance of endocrine cells from an undifferentiated stem cell. The third chapter is devoted to DES of the respiratory system and some aspects of its biological role, both, during development and adulthood. Neuroendocrine hyperplasia and neuroendocrine lung tumors are also addressed. Finally, the last chapter deals with the prostatic DES, discussing its probable functional role and its relevance in hormone-resistant prostatic carcinomas.

  5. Influence of caloric intake on experimental carcinogenesis: a review.

    Science.gov (United States)

    Kritchevsky, D; Klurfeld, D M

    1986-01-01

    The effect of caloric intake on tumor growth has been recognized for over 70 years. Inhibition of tumor growth depends primarily on the extent of caloric restriction, but tumor type, animal strain, and dietary composition all exert some influence. Caloric restriction is most effective when maintained during both initiation and promotion, but if limited to one of these phases, restriction during promotion appears to be the more effective modality. The types of tumor that have been studied include spontaneous mammary and lung tumors as well as tumors induced by organ-specific carcinogens or irradiation with ultraviolet light. Numerous investigators have studied the effects of fat, and a diet low in calories but high in fat is generally significantly more effective in inhibiting carcinogenesis than is a diet high in calories but low in fat. Mice fed high fat, low calorie diets exhibited 48% fewer chemically induced skin tumors and 61% fewer tumors induced by ultraviolet irradiation than did mice fed low fat, high calorie diets. Mice fed a diet containing 2% fat exhibited a 66% incidence of skin tumors, whereas mice fed an isocaloric diet containing 61% fat showed a 78% incidence. Rats whose diet was restricted in calories by 40% exhibited no mammary tumors (coconut oil as primary dietary fat) or 75% fewer tumors (corn oil as dietary fat) compared to ad libitum-fed controls; they also exhibited 47% fewer colonic tumors. The mechanism by which caloric restriction exerts its tumor-inhibiting effects remains to be elucidated.

  6. Cocarcinogenic and tumor-promoting agents in tobacco carcinogenesis.

    Science.gov (United States)

    Van Duuren, B L; Goldschmidt, B M

    1976-06-01

    A series of 21 tobacco smoke components and related compounds werere applied to mouse skin (50 female ICR/Ha Swiss mice/group) three times weekly with a low dose (5 mug/application) of benzo[a]pyrene (B[a]P). The test compounds were of five classes: aliphatic hydrocarbons, aromatic hydrocarbons, phenols, and long-chain acids and alcohols. The following compounds enhanced remarkably the carcinogenicity of B[a]P: catechol, pyrogallol, decane, undecane, pyrene, benzo[e]pyrene, and fluoranthene. The following compounds inhibited B[a]P carcinogenicity completely: esculin, quercetin, squalene, and oleic acid. Phenol, eugenol, resorcinol, hydroquinone, hexadecane, and limonene partially inhibited B[a]P carcinogenicity. Six of the 21 compounds were also tested as tumor promoters im two-stage carcinogenesis. No direct correlation existed between tumor-promoting activity and cocarcinogenic activity. The cocarcinogens pyrogallol and catechol did not show tumor-promoting activity. Decane, tetradecane, anthralin, and phorbol myristate acetate showed both types of activity. Structure-activity relationships and possible modes of action were described.

  7. Travelling Concepts

    DEFF Research Database (Denmark)

    Simonsen, Karen-Margrethe

    2013-01-01

    Review of "Travelling Concepts, Metaphors, and Narratives: Literary and Cultural Studies in an Age of Interdisciplinary Research" ed. by Sibylle Baumgarten, Beatrice Michaelis and Ansagar Nünning, Trier; Wissenschaftlicher Verlag Trier, 2012......Review of "Travelling Concepts, Metaphors, and Narratives: Literary and Cultural Studies in an Age of Interdisciplinary Research" ed. by Sibylle Baumgarten, Beatrice Michaelis and Ansagar Nünning, Trier; Wissenschaftlicher Verlag Trier, 2012...

  8. Beef meat promotion of dimethylhydrazine-induced colorectal carcinogenesis biomarkers is suppressed by dietary calcium.

    Science.gov (United States)

    Pierre, Fabrice; Santarelli, Raphaëlle; Taché, Sylviane; Guéraud, Françoise; Corpet, Denis E

    2008-05-01

    Red meat consumption is associated with increased risk of colorectal cancer. We have previously shown that haemin, Hb and red meat promote carcinogen-induced preneoplastic lesions: aberrant crypt foci (ACF) and mucin-depleted foci (MDF) in rats. We have also shown that dietary Ca, antioxidant mix and olive oil inhibit haemin-induced ACF promotion, and normalize faecal lipoperoxides and cytotoxicity. Here we tested if these strategies are effective also against red meat promotion in dimethylhydrazine-induced rats. Three diets with 60 % beef meat were supplemented with calcium phosphate (31 g/kg), antioxidant agents (rutin and butylated hydroxyanisole, 0.05 % each) and olive oil (5 %). ACF, MDF, faecal water cytotoxicity, thiobarbituric acid reactive substances (TBARS) and urinary 1,4-dihydroxynonane mercapturic acid (DHN-MA) were measured. Beef meat diet increased the number of ACF (+30 %) and MDF (+100 %) (P Promotion was associated with increased faecal water TBARs ( x 4) and cytotoxicity ( x 2), and urinary DHN-MA excretion ( x 15). Ca fully inhibited beef meat-induced ACF and MDF promotion, and normalized faecal TBARS and cytotoxicity, but did not reduce urinary DHN-MA. Unexpectedly, high-calcium control diet-fed rats had more MDF and ACF in the colon than low-Ca control diet-fed rats. Antioxidant mix and olive oil did not normalize beef meat promotion nor biochemical factors. The results confirm that haem causes promotion of colon carcinogenesis by red meat. They suggest that Ca can reduce colorectal cancer risk in meat-eaters. The results support the concept that toxicity associated with the excess of a useful nutrient may be prevented by another nutrient.

  9. Impaired CK1 delta activity attenuates SV40-induced cellular transformation in vitro and mouse mammary carcinogenesis in vivo.

    Directory of Open Access Journals (Sweden)

    Heidrun Hirner

    Full Text Available Simian virus 40 (SV40 is a powerful tool to study cellular transformation in vitro, as well as tumor development and progression in vivo. Various cellular kinases, among them members of the CK1 family, play an important role in modulating the transforming activity of SV40, including the transforming activity of T-Ag, the major transforming protein of SV40, itself. Here we characterized the effects of mutant CK1δ variants with impaired kinase activity on SV40-induced cell transformation in vitro, and on SV40-induced mammary carcinogenesis in vivo in a transgenic/bi-transgenic mouse model. CK1δ mutants exhibited a reduced kinase activity compared to wtCK1δ in in vitro kinase assays. Molecular modeling studies suggested that mutation N172D, located within the substrate binding region, is mainly responsible for impaired mutCK1δ activity. When stably over-expressed in maximal transformed SV-52 cells, CK1δ mutants induced reversion to a minimal transformed phenotype by dominant-negative interference with endogenous wtCK1δ. To characterize the effects of CK1δ on SV40-induced mammary carcinogenesis, we generated transgenic mice expressing mutant CK1δ under the control of the whey acidic protein (WAP gene promoter, and crossed them with SV40 transgenic WAP-T-antigen (WAP-T mice. Both WAP-T mice as well as WAP-mutCK1δ/WAP-T bi-transgenic mice developed breast cancer. However, tumor incidence was lower and life span was significantly longer in WAP-mutCK1δ/WAP-T bi-transgenic animals. The reduced CK1δ activity did not affect early lesion formation during tumorigenesis, suggesting that impaired CK1δ activity reduces the probability for outgrowth of in situ carcinomas to invasive carcinomas. The different tumorigenic potential of SV40 in WAP-T and WAP-mutCK1δ/WAP-T tumors was also reflected by a significantly different expression of various genes known to be involved in tumor progression, specifically of those involved in wnt-signaling and DNA

  10. Role of gastrin-peptides in Barrett's and colorectal carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    Eduardo Chueca; Angel Lanas; Elena Piazuelo

    2012-01-01

    Gastrin is the main hormone responsible for the stimulation of gastric acid secretion; in addition,gastrin and its derivatives exert proliferative and antiapoptotic effects on several cell types.Gastrin synthesis and secretion are increased in certain situations,for example,when proton pump inhibitors are used.The impact of sustained hypergastrinemia is currently being investigated.In vitro experiments and animal models have shown that prolonged hypergastrinemia may be related with higher cancer rates; although,this relationship is less clear in human beings.Higher gastrin levels have been shown to cause hyperplasia of several cell types; yet,the risk for developing cancer seems to be the same in normo-and hypergastrinemic patients.Some tumors also produce their own gastrin,which can act in an autocrine manner promoting tumor growth.Certain cancers are extremely dependent on gastrin to proliferate.Initial research focused only on the effects of amidated gastrins,but there has been an interest in intermediates of gastrin in the last few decades.These intermediates aren't biologically inactive;in fact,they may exert greater effects on proliferation and apoptosis than the completely processed forms.In certain gastrin overproduction states,they are the most abundant gastrin peptides secreted.The purpose of this review is to examine the gastrin biosynthesis process and to summarize the results from different studies evaluating the production,levels,and effects of the main forms of gastrin in different overexpression states and their possible relationship with Barrett's and colorectal carcinogenesis.

  11. Thymoquinone Attenuates Diethylnitrosamine Induction of Hepatic Carcinogenesis Through Antioxidant Signaling

    Directory of Open Access Journals (Sweden)

    Mohamed M. Sayed-Ahmed

    2010-01-01

    Full Text Available Hepatocellular carcinoma accounts for about 80–90% of all liver cancer and is the fourth most common cause of cancer mortality. Although there are many strategies for the treatment of liver cancer, chemoprevention seems to be the best strategy for lowering the incidence of this disease. Therefore, this study has been initiated to investigate whether thymoquinone (TQ, Nigella sativa derived-compound with strong antioxidant properties, supplementation could prevent initiation of hepatocarcinogenesis-induced by diethylnitrosamine (DENA, a potent initiator and hepatocarcinogen, in rats. Male Wistar albino rats were divided into four groups. Rats of Group 1 received a single intraperitoneal (I.P. injection of normal saline. Animals in Group 2 were given TQ (4 mg/kg/day in drinking water for 7 consecutive days. Rats of Group 3 were injected with a single dose of DENA (200 mg/kg, I.P.. Animals in Group 4 were received TQ and DENA. DENA significantly increased alanine transaminase (ALT, alkaline phosphatase (ALP, total bilirubin, thiobarbituric acid reactive substances (TBARS and total nitrate/nitrite (NOx and decreased reduced glutathione (GSH, glutathione peroxidase (GSHPx, glutathione-s-transferase (GST and catalase (CAT activity in liver tissues. Moreover, DENA decreased gene expression of GSHPx, GST and CAT and caused severe histopathological lesions in liver tissue. Interestingly, TQ supplementation completely reversed the biochemical and histopathological changes induced by DENA to the control values. In conclusion, data from this study suggest that: (1 decreased mRNA expression of GSHPx, CAT and GST during DENA-induced initiation of hepatic carcinogenesis, (2 TQ supplementation prevents the development of DENA-induced initiation of liver cancer by decreasing oxidative stress and preserving both the activity and mRNA expression of antioxidant enzymes.

  12. Colorectal carcinogenesis: Review of human and experimental animal studies

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    Tanaka Takuji

    2009-01-01

    Full Text Available This review gives a comprehensive overview of cancer development and links it to the current understanding of tumorigenesis and malignant progression in colorectal cancer. The focus is on human and murine colorectal carcinogenesis and the histogenesis of this malignant disorder. A summary of a model of colitis-associated colon tumorigenesis (an AOM/DSS model will also be presented. The earliest phases of colorectal oncogenesis occur in the normal mucosa, with a disorder of cell replication. The large majority of colorectal malignancies develop from an adenomatous polyp (adenoma. These can be defined as well-demarcated masses of epithelial dysplasia, with uncontrolled crypt cell proliferation. When neoplastic cells pass through the muscularis mucosa and infiltrate the submucosa, they are malignant. Carcinomas usually originate from pre-existing adenomas, but this does not imply that all polyps undergo malignant changes and does not exclude de novo oncogenesis. Besides adenomas, there are other types of pre-neoplasia, which include hyperplastic polyps, serrated adenomas, flat adenomas and dysplasia that occurs in the inflamed colon in associated with inflammatory bowel disease. Colorectal neoplasms cover a wide range of pre-malignant and malignant lesions, many of which can easily be removed during endoscopy if they are small. Colorectal neoplasms and/or pre-neoplasms can be prevented by interfering with the various steps of oncogenesis, which begins with uncontrolled epithelial cell replication, continues with the formation of adenomas and eventually evolves into malignancy. The knowledge described herein will help to reduce and prevent this malignancy, which is one of the most frequent neoplasms in some Western and developed countries.

  13. Possible Involvement of Pancreatic Fatty Infiltration in Pancreatic Carcinogenesis

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    Mika Hori

    2016-03-01

    Full Text Available Pancreatic cancer is difficult to diagnose in its early stage and is one of the most lethal human cancers. Thus, it is important to clarify its major risk factors, predictive factors and etiology. Here, we focus on fatty infiltration of the pancreas and suggest that it could be a risk factor for pancreatic cancer. Fatty infiltration of the pancreas is observed as ectopic adipocytes infiltrating the pancreatic tissue and is positively correlated with obesity and the prevalence of diabetes mellitus, which are risk factors for pancreatic cancer. However, whether fatty infiltration is a major risk factor for pancreatic cancer has not been established. Recent clinical studies show there is a positive correlation between fatty infiltration of the pancreas and pancreatic precancerous lesions or ductal adenocarcinomas. Animal experimental studies also show an association between fatty infiltration of the pancreas and pancreatic precancerous lesions or ductal adenocarcinomas development. Syrian golden hamsters, which are sensitive to chemical carcinogens in the pancreas, develop fatty infiltration of the pancreas with age. The combination of a high-fat diet and a chemical carcinogen that induces a K-ras mutation increases the severity of fatty infiltration of the pancreas. Thus, fatty infiltration of the pancreas is suggested to promote pancreatic carcinogenesis via a K-ras activating mutation. It is assumed that increased expression of adipokines and of inflammatory and proliferation-associated factors elicited by fatty infiltration of the pancreas may contribute to pancreatic precancerous lesions or ductal adenocarcinomas development. Accumulating evidence suggests that in addition to suppression of Ras activation, methods to modulate fatty infiltration in the pancreas can be considered as a strategy for preventing pancreatic cancer.

  14. Carcinogenesis ofnasopharyngeal carcinoma:an alternate hypothetical mechanism

    Institute of Scientific and Technical Information of China (English)

    Sharon Shuxian Poh; Melvin Lee Kiang Chua; Joseph TS Wee

    2016-01-01

    Current proposed mechanisms implicate both early and latent Epstein–Barr virus (EBV) infection in the carcinogenic cascade, whereas epidemiological studies have always associated nasopharyngeal carcinoma (NPC) with early child-hood EBV infection and with chronic ear, nose, and sinus conditions. Moreover, most patients with NPC present with IgA antibody titers to EBV capsid antigen (VCA-IgA), which can precede actual tumor presentation by several years. If early childhood EBV infection indeed constitutes a key event in NPC carcinogenesis, one would have to explain the inability to detect the virus in normal nasopharyngeal epithelium of patients at a high risk for EBV infection. It is perhaps possible that EBV resides within the salivary glands, instead of the epithelium, during latency. This claim is indirectly supported by observations that the East Asian phenotype shares the characteristics of an increased sus-ceptibility to NPC and immature salivary gland morphogenesis, the latter of which is inlfuenced by the association of salivary gland morphogenesis with an evolutionary variant of the human ectodysplasin receptor gene (EDAR), EDARV370A. Whether the immature salivary gland represents a more favorable nidus for EBV is uncertain, but in patients with infectious mononucleosis, EBV has been isolated in this anatomical organ. The presence of EBV-induced lymphoepitheliomas in the salivary glands and lungs further addresses the possibility of submucosal spread of the virus. Adding to the fact that the fossa of Rosen Müller contains a transformative zone active only in the ifrst decade of life, one might be tempted to speculate the possibility of an alternative carcinogenic cascade for NPC that is perhaps not dissimilar to the model of human papillomavirus and cervical cancer.

  15. Lateral Concepts

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    Christopher Gad

    2016-06-01

    Full Text Available This essay discusses the complex relation between the knowledges and practices of the researcher and his/her informants in terms of lateral concepts. The starting point is that it is not the prerogative of the (STS scholar to conceptualize the world; all our “informants” do it too. This creates the possibility of enriching our own conceptual repertoires by letting them be inflected by the concepts of those we study. In a broad sense, the lateral means that there is a many-to-many relation between domains of knowledge and practice. However, each specific case of the lateral is necessarily immanent to a particular empirical setting and form of inquiry. In this sense lateral concepts are radically empirical since it locates concepts within the field. To clarify the meaning and stakes of lateral concepts, we first make a contrast between lateral anthropology and Latour’s notion of infra-reflexivity. We end with a brief illustration and discussion of how lateral conceptualization can re-orient STS modes of inquiry, and why this matters.

  16. Genetic ablation of caspase-7 promotes solar-simulated light-induced mouse skin carcinogenesis: the involvement of keratin-17.

    Science.gov (United States)

    Lee, Mee-Hyun; Lim, Do Young; Kim, Myoung Ok; Lee, Sung-Young; Shin, Seung Ho; Kim, Jae Young; Kim, Sung-Hyun; Kim, Dong Joon; Jung, Sung Keun; Yao, Ke; Kundu, Joydeb Kumar; Lee, Hye Suk; Lee, Cheol-Jung; Dickinson, Sally E; Alberts, David; Bowden, G Timothy; Stratton, Steven; Curiel, Clara; Einspahr, Janine; Bode, Ann M; Surh, Young-Joon; Cho, Yong-Yeon; Dong, Zigang

    2015-11-01

    Solar ultraviolet irradiation is an environmental carcinogen that causes skin cancer. Caspase-7 is reportedly expressed at reduced levels in many cancers. The present study was designed to examine the role of caspase-7 in solar-simulated light (SSL)-induced skin cancer and to elucidate its underlying molecular mechanisms. Our study revealed that mice with genetic deficiency of caspase-7 are highly susceptible to SSL-induced skin carcinogenesis. Epidermal hyperplasia, tumor volume and the average number of tumors were significantly increased in caspase-7 knockout (KO) mice compared with SKH1 wild-type mice irradiated with SSL. The expression of cell proliferation markers, such as survivin and Ki-67, was elevated in SSL-irradiated skin of caspase-7 KO mice compared with those observed in SSL-exposed wild-type SKH1 mouse skin. Moreover, SSL-induced apoptosis was abolished in skin from caspase-7 KO mice. Two-dimensional gel electrophoresis, followed by matrix-assisted laser desorption/ionization-time-of-flight analysis of skin tissue lysates from SSL-irradiated SKH1 wild-type and caspase-7 KO mice revealed an aberrant induction of keratin-17 in caspase-7 KO mice. Immunohistochemical analysis of skin tumors also showed an increase of keratin-17 expression in caspase-7 KO mice compared with SKH1 wild-type mice. The expression of keratin-17 was also elevated in SSL-irradiated caspase-7 KO keratinocytes as well as in human basal cell carcinomas. The in vitro caspase activity assay showed keratin-17 as a substrate of caspase-7, but not caspase-3. Overall, our study demonstrates that genetic loss of caspase-7 promotes SSL-induced skin carcinogenesis by blocking caspase-7-mediated cleavage of keratin-17.

  17. Transcriptomic responses provide a new mechanistic basis for the chemopreventive effects of folic acid and tributyrin in rat liver carcinogenesis

    Science.gov (United States)

    Guariento, Aline H.; Furtado, Kelly S.; de Conti, Aline; Campos, Adriana; Purgatto, Eduardo; Carrilho, Jéssica; Shinohara, Elvira Maria Guerra; Tryndyak, Volodymyr; Han, Tao; Fuscoe, James C.; Ross, Sharon A.; Beland, Frederick A.; Pogribny, Igor P.; Moreno, Fernando S.

    2014-01-01

    The steady increase in the incidence and mortality of hepatocellular carcinoma (HCC) signifies a crucial need to understand better its pathogenesis to improve clinical management and prevention of the disease. The aim of this study was to investigate molecular mechanisms for the chemopreventive effects of folic acid and tributyrin alone or in combination on rat hepatocarcinogenesis. Male Wistar rats were subjected to a classic “resistant hepatocyte” model of liver carcinogenesis and treated with folic acid and tributyrin alone or in combination for 5 weeks during promotion stage. Treatment with folic acid and tributyrin alone or in combination strongly inhibited the development of glutathione-S-transferase placental form (GSTP)-positive foci. Microarray analysis showed significant changes in gene expression. A total of 501, 655, and 940 of differentially expressed genes, involved in cell cycle, p53-signaling, angiogenesis, and Wnt pathways, was identified in the livers of rats treated with folic acid, tributyrin or folic acid and tributyrin. A detailed analysis of these differentially expressed genes revealed that treatments inhibited angiogenesis in the preneoplastic livers. This was evidenced by the fact that 30 out of 77 differentially expressed genes common to all three treatments are involved in the regulation of the angiogenesis pathway. The inhibition of angiogenesis was confirmed by reduced levels of CD34 protein. In conclusion, the tumor-suppressing activity of folic acid and tributyrin is associated with inhibition of angiogenesis at early stages of rat liver carcinogenesis. Importantly, the combination of folic acid and tributyrin has stronger chemopreventive effect than each of the compounds alone. PMID:24302446

  18. Comparative evaluation of antiproliferative, antiangiogenic and apoptosis inducing potential of black tea polyphenols in the hamster buccal pouch carcinogenesis model

    Directory of Open Access Journals (Sweden)

    Prathiba Duvuru

    2007-01-01

    Full Text Available Abstract Background To evaluate the relative chemopreventive efficacy of two black tea polyphenols, Polyphenon-B [P-B] and BTF-35 on 7,12-dimethylbenz [a]anthracene (DMBA-induced hamster buccal pouch (HBP carcinogenesis. Methods Hamsters were divided into 6 groups. The right buccal pouches of animals in groups 1–3 were painted with 0.5% of DMBA three times a week for 14 weeks. While hamsters in group 1 received no further treatment, animals in groups 2 and 3 received diet containing 0.05% P-B and BTF-35 respectively, four weeks before DMBA painting that was continued until the end of the experiments. Animals in groups 4 and 5 were given P-B and BTF-35 alone respectively as in groups 2 and 3. Group 6 animals served as the untreated control. All the animals were sacrificed after 18 weeks. The expression of p21, cyclin D1, glutathione S-transferase pi (GST-P, nuclear factor kappa B (NF-κB, Bcl-2, Bax, cytochrome C, caspase-3, caspase-9, poly(ADP-ribose polymerase (PARP, cytokeratins and vascular endothelial growth factor (VEGF was analysed by RT-PCR, immunohistochemical and Western blot analyses. Results DMBA treated animals developed buccal pouch carcinomas that displayed increased expression of p21, cyclin D1, GST-P, NF-κB, cytokeratins, VEGF and Bcl-2 with decreased expression of Bax, cytochrome C, caspase-3, caspase-9, and PARP. Dietary administration of both P-B and BTF-35 reduced the incidence of DMBA-induced HBP carcinomas by modulating markers of cell proliferation, cell survival, tumour infiltration, angiogenesis, and apoptosis. Conclusion The results of the present study provide a mechanistic basis for the chemopreventive potential of black tea polyphenols. The greater efficacy of BTF-35 in inhibiting HBP carcinogenesis and modulating multiple molecular targets may have a potential role in the prevention of oral cancer.

  19. Influences of Dietary and Other Factors on Xenobiotic Metabolism and Carcinogenesis-A Review Article in Memory of Dr. Allan H. Conney (1930-2013).

    Science.gov (United States)

    Yang, Chung S

    2015-01-01

    This article reviews our current understanding on how xenobiotic metabolism and carcinogenesis are influenced by dietary and other factors. A major contributor to this research area was Dr. Allan Conney, and his contributions are highlighted. His studies on the induction of microsomal xenobiotic-metabolizing enzymes led to the characterization of the cytochrome P450 enzymes, which catalyze the metabolism of drugs, endogenous substrates, carcinogens and many other xenobiotics. These processes are influenced by drugs, diet, and other environmental factors. These studies provided the molecular basis for drug-drug, diet-drug, and herb-drug interactions. The elucidation of the metabolic activation of chemicals to their ultimate carcinogenic forms enables us to understand the molecular basis of chemical carcinogenesis. These studies led to many subsequent investigations on dietary approaches for cancer chemoprevention, including blocking of carcinogen activation, enhancing carcinogen detoxification, and influencing oncogenic pathways, which were carried out by Dr. Conney and others. The strengths and potential for practical application of these approaches are assessed herein.

  20. Pro-apoptotic and anti-inflammatory potential of andrographolide during 7,12-dimethylbenz[a]anthracene induced hamster buccal pouch carcinogenesis

    Directory of Open Access Journals (Sweden)

    Karthikeyan Sekar

    2012-08-01

    Full Text Available Objective: Aim of the present study was to investigate the modulating effect of andrographolide on apoptotic and inflammatory markers during 7,12-dimethyl-benz[a]anthracene (DMBA induced hamster buccal pouch carcinogenesis. Methods: Oral tumors were developed in the buccal pouch of golden Syrian hamsters by painting with 0.5% DMBA in liquid paraffin three times a week for 14 weeks. The expression pattern of molecular markers were assayed using immunohistochemistry (p53, Bcl-2 and Bax, ELISA (COX-2 and real-time PCR (NFκB. Results: We noticed 100% tumor formation accompanied by deregulation in the apoptotic and inflammatory markers in the buccal mucosa of hamsters treated with DMBA alone. Oral administration of andrographolide at a dose of 50 mg/kg b.w to hamsters treated with DMBA, not only completely prevented the tumor formation but also modulated the status of above mentioned molecular markers in favor of inhibiting cell proliferation as evidenced by no tumor formation. Conclusion: The present study suggests that the anti-tumor effect of andrographolide could partly be attributed to its apoptotic and anti-inflammatory potential during DMBA-induced hamster buccal pouch carcinogenesis. [J Exp Integr Med 2012; 2(4: 313-319

  1. Combination of computational methods, adsorption isotherms and selectivity tests for the conception of a mixed non-covalent-semi-covalent molecularly imprinted polymer of vanillin.

    Science.gov (United States)

    Puzio, Kinga; Delépée, Raphaël; Vidal, Richard; Agrofoglio, Luigi A

    2013-08-06

    A novel molecularly imprinted polymer (MIP) for vanillin was prepared by photo initiated polymerization in dichloromethane using a mixed semi-covalent and non-covalent imprinting strategy. Taking polymerisable syringaldehyde as "dummy" template, acrylamide was chosen as functional monomer on B3LYP/6-31+G(d,p) density functional theory computational method basis with counterpoise. The binding parameters for the recognition of vanillin on imprinted polymers were studied with three different isotherm models (Langmuir, bi-Langmuir and Langmuir-Freundlich) and compared. The results indicate an heterogeneity of binding sites. It was found and proved by DFT calculations that the specific binding of vanillin in the cavities is due to non-covalent interactions of the template with the hydroxyphenyl- and the amide-moieties. The binding geometry of vanillin in the MIP cavity was also modelled. The obtained MIP is highly specific for vanillin (with an imprinting factor of 7.4) and was successfully applied to the extraction of vanillin from vanilla pods, red wine spike with vanillin, natural and artificial vanilla sugar with a recovery of 80%.

  2. Chemical and Molecular Biological Aspects of Alkylhydrazine-Induced Carcinogenesis in Human Cells in Vitro. Revised

    Science.gov (United States)

    1984-04-01

    DMH) and the metabolite methylazoxymethanol acetate ( MAMA ) have been shown to induce cancer in vivo in several species of rodents producing a variety of...The Pharmaceutical and Toxicological Research Institute (PTRI) I Co-Director, Developmental Chemotherapeutics, OSU Comprehensive Cancer Center...NNL[Methyl-l 4 C] I -dimethylhydrazine) of high specific activity Chapter III - Synthesis of (14 C] -labeled methylazoxymethanol 13 acetate ( MAMA ) of

  3. Molecular analysis of the HPJ-JT syndrome and sporadic parathyroid carcinogenesis

    NARCIS (Netherlands)

    Haven, Carola José

    2008-01-01

    HPT-JT syndrome is a rare disease characterized by parathyroid tumours (with a high percentage of carcinomas), jaw and kidney tumours. In this thesis, the clinical and genetic features of the HPT-JT syndrome and the relationship between the HRPT2 gene and parathyroid tumours were investigated. We

  4. Differential expression in normal-adenoma-carcinoma sequence suggests complex molecular carcinogenesis in colon.

    Science.gov (United States)

    Lee, Seungkoo; Bang, Seunghyun; Song, Kyuyoung; Lee, Inchul

    2006-10-01

    The majority of colon cancers develop from pre-existing adenomas. We analyzed the expression profiles in the sequence of normal colon crypts, adenomas and early-stage carcinomas using microdissected cells from tubular adenomas with foci of malignant transformation. Differentially expressed genes were detected between normal-adenoma and adenoma-carcinoma, and were grouped according to the patterns of expression changes in the sequence. Down-regulated genes in the sequence included PLA2G2A, TSPAN1, PDCD4, FCGBP, AATK, EPLIN, FABP1, AGR2, MTUS1, TSC1, galectin 4 and MT1F. PLA2G2A has been shown to suppress colon tumorigenesis in mice, but the pathobiological role in humans has been controversial. Our data showed continuous down-regulation of PLA2G2A in the sequence supporting an implication in human colon cancer. Tumor suppressor and/ or proapoptotic activities have also been reported in other genes. Up-regulated genes included ribosomal proteins, IER3 and TPR. TGF-beta2 and matrix metalloproteinase 23B were up-regulated in carcinoma but not in adenoma, supporting the pathobiological roles in malignant transformation. Differentially expressed genes partly coincided with those in the adenoma-carcinoma sequence of the stomach, which was published previously, suggesting a partial overlap between the adenoma-carcinoma sequences of the colon and stomach.

  5. A review of dietary factors and its influence on DNA methylation in colorectal carcinogenesis.

    Science.gov (United States)

    Arasaradnam, R P; Commane, D M; Bradburn, D; Mathers, J C

    2008-01-01

    Colorectal cancer (CRC) is the most common cancer in non-smokers posing a significant health burden in the UK. Observational studies lend support to the impact of environmental factors especially diet on colorectal carcinogenesis. Significant advances have been made in understanding the biology of CRC carcinogenesis in particular epigenetic modifications such as DNA methylation. DNA methylation is thought to occur at least as commonly as inactivation of tumor suppressor genes. In fact compared with other human cancers, promoter gene methylation occurs most commonly within the gastrointestinal tract. Emerging data suggest the direct influence of certain micronutrients for example folic acid, selenium as well as interaction with toxins such as alcohol on DNA methylation. Such interactions are likely to have a mechanistic impact on CRC carcinogenesis through the methylation pathway but also, may offer possible therapeutic potential as nutraceuticals.

  6. Chronic Inflammation-Related HPV: A Driving Force Speeds Oropharyngeal Carcinogenesis.

    Science.gov (United States)

    Liu, Xin; Ma, Xiangrui; Lei, Zhengge; Feng, Hao; Wang, Shasha; Cen, Xiao; Gao, Shiyu; Jiang, Yaping; Jiang, Jian; Chen, Qianming; Tang, Yajie; Tang, Yaling; Liang, Xinhua

    2015-01-01

    Oropharyngeal squamous cell carcinoma (OPSCC) has been known to be a highly aggressive disease associated with human papilloma virus (HPV) infection. To investigate the relationship between HPV and chronic inflammation in oropharyngeal carcinogenesis, we collected 140 oral mucous fresh specimens including 50 OPSCC patients, 50 cancer in situ, 30 precancerous lesions, and 10 normal oral mucous. Our data demonstrated that there was a significantly higher proportion of severe chronic inflammation in dysplastic epithelia in comparison with that in normal tissues (Pchronic inflammation degrees from mild to severe inflammation (Pinflammation response and immune suppression in HPV-positive OPSCC. These indicated that persistent chronic inflammation-related HPV infection might drive oropharyngeal carcinogenesis and MDSCs might pay an important role during this process. Thus, a combination of HPV infection and inflammation expression might become a helpful biomedical marker to predict oropharyngeal carcinogenesis.

  7. Green tea catechin extract in intervention of chronic breast cell carcinogenesis induced by environmental carcinogens.

    Science.gov (United States)

    Rathore, Kusum; Wang, Hwa-Chain Robert

    2012-03-01

    Sporadic breast cancers are mainly attributable to long-term exposure to environmental factors, via a multi-year, multi-step, and multi-path process of tumorigenesis involving cumulative genetic and epigenetic alterations in the chronic carcinogenesis of breast cells from a non-cancerous stage to precancerous and cancerous stages. Epidemiologic and experimental studies have suggested that green tea components may be used as preventive agents for breast cancer control. In our research, we have developed a cellular model that mimics breast cell carcinogenesis chronically induced by cumulative exposures to low doses of environmental carcinogens. In this study, we used our chronic carcinogenesis model as a target system to investigate the activity of green tea catechin extract (GTC) at non-cytotoxic levels in intervention of cellular carcinogenesis induced by cumulative exposures to pico-molar 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and benzo[a]pyrene (B[a]P). We identified that GTC, at a non-cytotoxic, physiologically achievable concentration of 2.5 µg/mL, was effective in suppressing NNK- and B[a]P-induced cellular carcinogenesis, as measured by reduction of the acquired cancer-associated properties of reduced dependence on growth factors, anchorage-independent growth, increased cell mobility, and acinar-conformational disruption. We also detected that intervention of carcinogen-induced elevation of reactive oxygen species (ROS), increase of cell proliferation, activation of the ERK pathway, DNA damage, and changes in gene expression may account for the mechanisms of GTC's preventive activity. Thus, GTC may be used in dietary and chemoprevention of breast cell carcinogenesis associated with long-term exposure to low doses of environmental carcinogens.

  8. The Combination of Three Natural Compounds Effectively Prevented Lung Carcinogenesis by Optimal Wound Healing.

    Directory of Open Access Journals (Sweden)

    Linxin Liu

    Full Text Available The tumor stroma has been described as "normal wound healing gone awry". We explored whether the restoration of a wound healing-like microenvironment may facilitate tumor healing. Firstly, we screened three natural compounds (shikonin, notoginsenoside R1 and aconitine from wound healing agents and evaluated the efficacies of wound healing microenvironment for limiting single agent-elicited carcinogenesis and two-stage carcinogenesis. The results showed that three compounds used alone could promote wound healing but had unfavorable efficacy to exert wound healing, and that the combination of three compounds made up treatment disadvantage of a single compound in wound healing and led to optimal wound healing. Although individual treatment with these agents may prevent cancer, they were not effective for the treatment of established tumors. However, combination treatment with these three compounds almost completely prevented urethane-induced lung carcinogenesis and reduced tumor burden. Different from previous studies, we found that urethane-induced lung carcinogenesis was associated with lung injury independent of pulmonary inflammation. LPS-induced pulmonary inflammation did not increase lung carcinogenesis, whereas decreased pulmonary inflammation by macrophage depletion promoted lung carcinogenesis. In addition, urethane damaged wound healing in skin excision wound model, reversed lung carcinogenic efficacy by the combination of three compounds was consistent with skin wound healing. Further, the combination of these three agents reduced the number of lung cancer stem cells (CSCs by inducing cell differentiation, restoration of gap junction intercellular communication (GJIC and blockade of the epithelial-to-mesenchymal transition (EMT. Our results suggest that restoration of a wound healing microenvironment represents an effective strategy for cancer prevention.

  9. Astrophysical Concepts

    CERN Document Server

    Harwit, Martin

    2006-01-01

    This classic text, aimed at senior undergraduates and beginning graduate students in physics and astronomy, presents a wide range of astrophysical concepts in sufficient depth to give the reader a quantitative understanding of the subject. Emphasizing physical concepts, the book outlines cosmic events but does not portray them in detail: it provides a series of astrophysical sketches. For this fourth edition, nearly every part of the text has been reconsidered and rewritten, new sections have been added to cover recent developments, and others have been extensively revised and brought up to date. The book begins with an outline of the scope of modern astrophysics and enumerates some of the outstanding problems faced in the field today. The basic physics needed to tackle these questions are developed in the next few chapters using specific astronomical processes as examples. The second half of the book enlarges on these topics and shows how we can obtain quantitative insight into the structure and evolution of...

  10. Overexpression of LSD1 contributes to human carcinogenesis through chromatin regulation in various cancers.

    Science.gov (United States)

    Hayami, Shinya; Kelly, John D; Cho, Hyun-Soo; Yoshimatsu, Masanori; Unoki, Motoko; Tsunoda, Tatsuhiko; Field, Helen I; Neal, David E; Yamaue, Hiroki; Ponder, Bruce A J; Nakamura, Yusuke; Hamamoto, Ryuji

    2011-02-01

    A number of histone demethylases have been identified and biochemically characterized, but the pathological roles of their dysfunction in human disease like cancer have not been well understood. Here, we demonstrate important roles of lysine-specific demethylase 1 (LSD1) in human carcinogenesis. Expression levels of LSD1 are significantly elevated in human bladder carcinomas compared with nonneoplastic bladder tissues (p human embryonic kidney fibroblast cells. Expression profile analysis showed that LSD1 could affect the expression of genes involved in various chromatin-modifying pathways such as chromatin remodeling at centromere, centromeric heterochromatin formation and chromatin assembly, indicating its essential roles in carcinogenesis through chromatin modification.

  11. Lung carcinogenesis from chronic obstructive pulmonary disease: characteristics of lung cancer from COPD and contribution of signal transducers and lung stem cells in the inflammatory microenvironment.

    Science.gov (United States)

    Sekine, Yasuo; Hata, Atsushi; Koh, Eitetsu; Hiroshima, Kenzo

    2014-07-01

    Chronic obstructive pulmonary disease (COPD) and lung cancer are closely related. The annual incidence of lung cancer arising from COPD has been reported to be 0.8-1.7 %. Treatment of lung cancer from COPD is very difficult due to low cardiopulmonary function, rapid tumor growth, and resistance to molecularly targeted therapies. Chronic inflammation caused by toxic gases can induce COPD and lung cancer. Carcinogenesis in the inflammatory microenvironment occurs during cycles of tissue injury and repair. Cellular damage can induce induction of necrotic cell death and loss of tissue integrity. Quiescent normal stem cells or differentiated progenitor cells are introduced to repair injured tissues. However, inflammatory mediators may promote the growth of bronchioalveolar stem cells, and activation of NF-κB and signal transducer and activator of transcription 3 (STAT3) play crucial roles in the development of lung cancer from COPD. Many of the protumorgenic effects of NF-κB and STAT3 activation in immune cells are mediated through paracrine signaling. NF-κB and STAT3 also contribute to epithelial-mesenchymal transition. To improve lung cancer treatment outcomes, lung cancer from COPD must be overcome. In this article, we review the characteristics of lung cancer from COPD and the mechanisms of carcinogenesis in the inflammatory microenvironment. We also propose the necessity of identifying the mechanisms underlying progression of COPD to lung cancer, and comment on the clinical implications with respect to lung cancer prevention, screening, and therapy.

  12. In Vivo SILAC-Based Proteomics Reveals Phosphoproteome Changes during Mouse Skin Carcinogenesis

    DEFF Research Database (Denmark)

    Zanivan, Sara; Meves, Alexander; Behrendt, Kristina;

    2013-01-01

    SILAC technology in combination with high-resolution mass spectrometry (MS) can be successfully used to measure phosphoproteomes in vivo. Here, Zanivan, Mann, and colleagues have applied SILAC-based MS to investigate phosphoproteomic changes during skin carcinogenesis, using the DMBA/TPA two...

  13. Effects of dietary fat on virus-induced pancreatic carcinogenesis in guinea fowl

    NARCIS (Netherlands)

    Kirev, T.; Woutersen, R.A.; Kril, A.

    2002-01-01

    The present study was performed to assess the effects of diets supplemented with low (5%) and high (20%) corn oil on a Pts 56 retrovirus-induced model of pancreatic carcinogenesis in guinea fowl. The early microscopic lesions appear after 3 mo after virus treatment and progress over time. Eight to 1

  14. Molecular basis of colorectal cancer: Towards an individualized management?

    Directory of Open Access Journals (Sweden)

    J. Perea

    Full Text Available Colorectal cancer (CRC has become a highly relevant condition nowadays. In this respect, advances in the understanding of its molecular basis are key for an adequate management. From the time when the adenoma-carcinoma sequence was formulated as a carcinogenesis model to this day, when, among other things, three major carcinogenic pathways have been identified, the CRC concept has evolved from that of a single disease to the notion that each CRC is a differentiated condition in itself. The suppressor or chromosome instability pathway, the mutator or microsatellite instability pathway, and the methylator or CpG island methylation pathway allow various phenotypes to be identified within CRC. Similarly, the presence of different changes in certain genes confers several behaviors on CRC from both the prognostic and responsive standpoints to specific therapies. However, this apparent complexity does help develop the clinical management of this disease through the identification of novel, more specific therapy targets, and also markers for various behaviors within the condition, which will most likely lead us to an individualized management for these patients.

  15. Molecular basis of colorrectal cancer: towards an individualized management?

    Science.gov (United States)

    Perea, J; Lomas, M; Hidalgo, M

    2011-01-01

    Colorectal cancer (CRC) has become a highly relevant condition nowadays. In this respect, advances in the understanding of its molecular basis are key for an adequate management. From the time when the adenoma-carcinoma sequence was formulated as a carcinogenesis model to this day, when -among other things- three major carcinogenic pathways have been identified, the CRC concept has evolved from that of a single disease to the notion that each CRC is a differentiated condition in itself. The suppressor or chromosome instability pathway, the mutator or microsatellite instability pathway, and the methylator or CpG island methylation pathway allow various phenotypes to be identified within CRC. Similarly, the presence of different changes in certain genes confers several behaviors on CRC from both the prognostic and responsive standpoints to specific therapies. However, this apparent complexity does help develop the clinical management of this disease through the identification of novel, more specific therapy targets, and also markers for various behaviors within the condition, which will most likely lead us to an individualized management for these patients.

  16. Toxicogenomic outcomes predictive of forestomach carcinogenesis following exposure to benzo(a)pyrene: Relevance to human cancer risk

    Energy Technology Data Exchange (ETDEWEB)

    Labib, Sarah, E-mail: Sarah.Labib@hc-sc.gc.ca; Guo, Charles H., E-mail: Charles.Guo@hc-sc.gc.ca; Williams, Andrew, E-mail: Andrew.Williams@hc-sc.gc.ca; Yauk, Carole L., E-mail: Carole.Yauk@hc-sc.gc.ca; White, Paul A., E-mail: Paul.White@hc-sc.gc.ca; Halappanavar, Sabina, E-mail: Sabina.Halappanavar@hc-sc.gc.ca

    2013-12-01

    Forestomach tumors are observed in mice exposed to environmental carcinogens. However, the relevance of this data to humans is controversial because humans lack a forestomach. We hypothesize that an understanding of early molecular changes after exposure to a carcinogen in the forestomach will provide mode-of-action information to evaluate the applicability of forestomach cancers to human cancer risk assessment. In the present study we exposed mice to benzo(a)pyrene (BaP), an environmental carcinogen commonly associated with tumors of the rodent forestomach. Toxicogenomic tools were used to profile gene expression response in the forestomach. Adult Muta™Mouse males were orally exposed to 25, 50, and 75 mg BaP/kg-body-weight/day for 28 consecutive days. The forestomach was collected three days post-exposure. DNA microarrays, real-time RT-qPCR arrays, and protein analyses were employed to characterize responses in the forestomach. Microarray results showed altered expression of 414 genes across all treatment groups (± 1.5 fold; false discovery rate adjusted P ≤ 0.05). Significant downregulation of genes associated with phase II xenobiotic metabolism and increased expression of genes implicated in antigen processing and presentation, immune response, chemotaxis, and keratinocyte differentiation were observed in treated groups in a dose-dependent manner. A systematic comparison of the differentially expressed genes in the forestomach from the present study to differentially expressed genes identified in human diseases including human gastrointestinal tract cancers using the NextBio Human Disease Atlas showed significant commonalities between the two models. Our results provide molecular evidence supporting the use of the mouse forestomach model to evaluate chemically-induced gastrointestinal carcinogenesis in humans. - Highlights: • Benzo(a)pyrene-mediated transcriptomic response in the forestomach was examined. • The immunoproteosome subunits and MHC class I

  17. Deficient expression of aldehyde dehydrogenase 1A1 is consistent with increased sensitivity of Gorlin syndrome patients to radiation carcinogenesis.

    Science.gov (United States)

    Wright, Aaron T; Magnaldo, Thierry; Sontag, Ryan L; Anderson, Lindsey N; Sadler, Natalie C; Piehowski, Paul D; Gache, Yannick; Weber, Thomas J

    2015-06-01

    Human phenotypes that are highly susceptible to radiation carcinogenesis have been identified. Sensitive phenotypes often display robust regulation of molecular features that modify biological response, which can facilitate identification of the pathways/networks that contribute to pathophysiological outcomes. Here we interrogate primary dermal fibroblasts isolated from Gorlin syndrome patients (GDFs), who display a pronounced inducible tumorigenic response to radiation, in comparison to normal human dermal fibroblasts (NHDFs). Our approach exploits newly developed thiol reactive probes to define changes in protein thiol profiles in live cell studies, which minimizes artifacts associated with cell lysis. Redox probes revealed deficient expression of an apparent 55 kDa protein thiol in GDFs from independent Gorlin syndrome patients, compared with NHDFs. Proteomics tentatively identified this protein as aldehyde dehydrogenase 1A1 (ALDH1A1), a key enzyme regulating retinoic acid synthesis, and ALDH1A1 protein deficiency in GDFs was confirmed by Western blot. A number of additional protein thiol differences in GDFs were identified, including radiation responsive annexin family members and lamin A/C. Collectively, candidates identified in our study have plausible implications for radiation health effects and cancer susceptibility.

  18. Dietary chlorophyllin abrogates TGFβ signaling to modulate the hallmark capabilities of cancer in an animal model of forestomach carcinogenesis.

    Science.gov (United States)

    Thiyagarajan, Paranthaman; Kavitha, Krishnamurthy; Thautam, Avaneesh; Dixit, Madhulika; Nagini, Siddavaram

    2014-07-01

    Transforming growth factor (TGF) β signaling pathway plays a central role in the regulation of a wide range of cellular processes involved in the acquisition of the malignant phenotype. The objective of the present study was to examine the effect of chlorophyllin, a semisynthetic derivative of chlorophyll on N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)--induced rat forestomach carcinogenesis based on the modulation of TGFβ signaling and the downstream target genes associated with cell proliferation, apoptosis evasion, angiogenesis, invasion, and metastasis. We determined the effect of dietary chlorophyllin on TGFβ signaling and the downstream events-cell proliferation, apoptosis evasion, angiogenesis, invasion, and metastasis by semiquantitative and quantitative reverse transcription (RT)-PCR, Western blot, and immunohistochemical analyses. We further validated the inhibition of TGFβ signaling by chlorophyllin by performing molecular docking studies. We found that dietary supplementation of chlorophyllin at 4-mg/kg bw inhibits the development of MNNG-induced forestomach carcinomas by downregulating the expression of TGFβ RI, TGFβ RII, and Smad 2 and 4 and upregulating Smad 7, thereby abrogating canonical TGFβ signaling. Docking interactions also confirmed the inhibition of TGFβ signaling by chlorophyllin via inactivating TGFβ RI. Furthermore, attenuation of TGFβ signaling by chlorophyllin also blocked cell proliferation, angiogenesis, invasion, and metastasis, and induced mitochondria-mediated cell death. Dietary chlorophyllin that simultaneously abrogates TGFβ signaling pathway and the key hallmark events of cancer appear to be an ideal candidate for cancer chemoprevention.

  19. Mathematical concepts

    CERN Document Server

    Jost, Jürgen

    2015-01-01

    The main intention of this book is to describe and develop the conceptual, structural and abstract thinking of mathematics. Specific mathematical structures are used to illustrate the conceptual approach; providing a deeper insight into mutual relationships and abstract common features. These ideas are carefully motivated, explained and illustrated by examples so that many of the more technical proofs can be omitted. The book can therefore be used: ·         simply as an overview of the panorama of mathematical structures and the relations between them, to be supplemented by more detailed texts whenever you want to acquire a working knowledge of some structure ·         by itself as a first introduction to abstract mathematics ·         together with existing textbooks, to put their results into a more general perspective ·         to gain a new and hopefully deeper perspective after having studied such textbooks Mathematical Concepts has a broader scope and is less detaile...

  20. Chemoprevention of Rat Mammary Carcinogenesis by Apiaceae Spices

    Science.gov (United States)

    Aqil, Farrukh; Jeyabalan, Jeyaprakash; Munagala, Radha; Ravoori, Srivani; Vadhanam, Manicka V.; Schultz, David J.; Gupta, Ramesh C.

    2017-01-01

    Scientific evidence suggests that many herbs and spices have medicinal properties that alleviate symptoms or prevent disease. In this study, we examined the chemopreventive effects of the Apiaceae spices, anise, caraway, and celery seeds against 17β-estrogen (E2)-mediated mammary tumorigenesis in an ACI (August-Copenhagen Irish) rat model. Female ACI rats were given either control diet (AIN 93M) or diet supplemented with 7.5% (w/w) of anise, caraway, or celery seed powder. Two weeks later, one half of the animals in each group received subcutaneous silastic implants of E2. Diet intake and body weight were recorded weekly, and animals were euthanized after 3 and 12 weeks. E2-treatment showed significantly (2.1- and 3.4-fold) enhanced growth of pituitary gland at 3 and 12 weeks, respectively. All test spices significantly offset the pituitary growth by 12 weeks, except celery which was effective as early as three weeks. Immunohistochemical analysis for proliferative cell nuclear antigen (PCNA) in mammary tissues showed significant reduction in E2-mediated mammary cell proliferation. Test spices reduced the circulating levels of both E2 and prolactin at three weeks. This protection was more pronounced at 12 weeks, with celery eliciting the highest effect. RT-PCR and western blot analysis were performed to determine the potential molecular targets of the spices. Anise and caraway diets significantly offset estrogen-mediated overexpression of both cyclin D1 and estrogen receptor α (ERα). The effect of anise was modest. Likewise, expression of CYP1B1 and CYP1A1 was inhibited by all test spices. Based on short-term molecular markers, caraway was selected over other spices based on its enhanced effect on estrogen-associated pathway. Therefore, a tumor-end point study in ACI rats was conducted with dietary caraway. Tumor palpation from 12 weeks onwards revealed tumor latency of 29 days in caraway-treated animals compared with first tumor appearance at 92 days in control

  1. Chemoprevention of Rat Mammary Carcinogenesis by Apiaceae Spices

    Directory of Open Access Journals (Sweden)

    Farrukh Aqil

    2017-02-01

    Full Text Available Scientific evidence suggests that many herbs and spices have medicinal properties that alleviate symptoms or prevent disease. In this study, we examined the chemopreventive effects of the Apiaceae spices, anise, caraway, and celery seeds against 17β-estrogen (E2-mediated mammary tumorigenesis in an ACI (August-Copenhagen Irish rat model. Female ACI rats were given either control diet (AIN 93M or diet supplemented with 7.5% (w/w of anise, caraway, or celery seed powder. Two weeks later, one half of the animals in each group received subcutaneous silastic implants of E2. Diet intake and body weight were recorded weekly, and animals were euthanized after 3 and 12 weeks. E2-treatment showed significantly (2.1- and 3.4-fold enhanced growth of pituitary gland at 3 and 12 weeks, respectively. All test spices significantly offset the pituitary growth by 12 weeks, except celery which was effective as early as three weeks. Immunohistochemical analysis for proliferative cell nuclear antigen (PCNA in mammary tissues showed significant reduction in E2-mediated mammary cell proliferation. Test spices reduced the circulating levels of both E2 and prolactin at three weeks. This protection was more pronounced at 12 weeks, with celery eliciting the highest effect. RT-PCR and western blot analysis were performed to determine the potential molecular targets of the spices. Anise and caraway diets significantly offset estrogen-mediated overexpression of both cyclin D1 and estrogen receptor α (ERα. The effect of anise was modest. Likewise, expression of CYP1B1 and CYP1A1 was inhibited by all test spices. Based on short-term molecular markers, caraway was selected over other spices based on its enhanced effect on estrogen-associated pathway. Therefore, a tumor-end point study in ACI rats was conducted with dietary caraway. Tumor palpation from 12 weeks onwards revealed tumor latency of 29 days in caraway-treated animals compared with first tumor appearance at 92

  2. RAGE, carboxylated glycans and S100A8/A9 play essential roles in colitis-associated carcinogenesis.

    Science.gov (United States)

    Turovskaya, Olga; Foell, Dirk; Sinha, Pratima; Vogl, Thomas; Newlin, Robbin; Nayak, Jonamani; Nguyen, Mien; Olsson, Anna; Nawroth, Peter P; Bierhaus, Angelika; Varki, Nissi; Kronenberg, Mitchell; Freeze, Hudson H; Srikrishna, Geetha

    2008-10-01

    Patients with inflammatory bowel diseases are at increased risk for colorectal cancer, but the molecular mechanisms linking inflammation and cancer are not well defined. We earlier showed that carboxylated N-glycans expressed on receptor for advanced glycation end products (RAGE) and other glycoproteins mediate colitis through activation of nuclear factor kappa B (NF-kappaB). Because NF-kappaB signaling plays a critical role in the molecular pathogenesis of colitis-associated cancer (CAC), we reasoned that carboxylated glycans, RAGE and its ligands might promote CAC. Carboxylated glycans are expressed on a subpopulation of RAGE on colon cancer cells and mediate S100A8/A9 binding to RAGE. Colon tumor cells express binding sites for S100A8/A9 and binding leads to activation of NF-kappaB and tumor cell proliferation. Binding, downstream signaling and tumor cell proliferation are blocked by mAbGB3.1, an anti-carboxylate glycan antibody, and by anti-RAGE. In human colon tumor tissues and in a mouse model of CAC, we found that myeloid progenitors expressing S100A8 and S100A9 infiltrate regions of dysplasia and adenoma. mAbGB3.1 administration markedly reduces chronic inflammation and tumorigenesis in the mouse model of CAC and RAGE-deficient mice are resistant to the onset of CAC. These findings show that RAGE, carboxylated glycans and S100A8/A9 play essential roles in tumor-stromal interactions, leading to inflammation-associated colon carcinogenesis.

  3. Toxicogenomic outcomes predictive of forestomach carcinogenesis following exposure to benzo(a)pyrene: relevance to human cancer risk.

    Science.gov (United States)

    Labib, Sarah; Guo, Charles H; Williams, Andrew; Yauk, Carole L; White, Paul A; Halappanavar, Sabina

    2013-12-01

    Forestomach tumors are observed in mice exposed to environmental carcinogens. However, the relevance of this data to humans is controversial because humans lack a forestomach. We hypothesize that an understanding of early molecular changes after exposure to a carcinogen in the forestomach will provide mode-of-action information to evaluate the applicability of forestomach cancers to human cancer risk assessment. In the present study we exposed mice to benzo(a)pyrene (BaP), an environmental carcinogen commonly associated with tumors of the rodent forestomach. Toxicogenomic tools were used to profile gene expression response in the forestomach. Adult Muta™Mouse males were orally exposed to 25, 50, and 75 mgBaP/kg-body-weight/day for 28 consecutive days. The forestomach was collected three days post-exposure. DNA microarrays, real-time RT-qPCR arrays, and protein analyses were employed to characterize responses in the forestomach. Microarray results showed altered expression of 414 genes across all treatment groups (± 1.5 fold; false discovery rate adjusted P ≤ 0.05). Significant downregulation of genes associated with phase II xenobiotic metabolism and increased expression of genes implicated in antigen processing and presentation, immune response, chemotaxis, and keratinocyte differentiation were observed in treated groups in a dose-dependent manner. A systematic comparison of the differentially expressed genes in the forestomach from the present study to differentially expressed genes identified in human diseases including human gastrointestinal tract cancers using the NextBio Human Disease Atlas showed significant commonalities between the two models. Our results provide molecular evidence supporting the use of the mouse forestomach model to evaluate chemically-induced gastrointestinal carcinogenesis in humans.

  4. Chemomodulatory Potential of Flaxseed Oil Against DMBA/Croton Oil-Induced Skin Carcinogenesis in Mice.

    Science.gov (United States)

    Sharma, Jyoti; Singh, Ritu; Goyal, P K

    2016-09-01

    The present study was conducted to evaluate the potential of flaxseed oil to prevent chemically induced skin cancer in mice. Cancer was induced on 2-stage skin carcinogenesis model by single topical application of 7,12 dimethylbenz [a]anthracene (DMBA), as, initiator, and two weeks later it was promoted by croton oil treatment thrice a week on the dorsal surface of mice for 16 weeks. Flaxseed oil (FSO; 100µL/animal/d) was orally administered 1 week before and 1 week after DMBA application (Peri-initiation stage). The animals of the FSO-administered group showed a significant reduction in tumor incidence (76.67%), cumulative number of tumors (37), tumor yield (3.7), and tumor burden (4.81) when compared with the carcinogen-treated control animals. Biochemical parameters in skin and liver tissue such as LPO and phase I enzymes were significantly (P croton oil-induced skin carcinogenesis in mice.

  5. The pleiotropic roles of transforming growth factor beta inhomeostasis and carcinogenesis of endocrine organs.

    Energy Technology Data Exchange (ETDEWEB)

    Fleisch, Markus C.; Maxwell, Christopher A.; Barcellos-Hoff,Mary-Helen

    2006-01-13

    Transforming growth factor beta (TGF-beta) is a ubiquitous cytokine that plays a critical role in numerous pathways regulating cellular and tissue homeostasis. TGF-beta is regulated by hormones and is a primary mediator of hormone response in uterus, prostate and mammary gland. This review will address the role of TGF-beta in regulating hormone dependent proliferation and morphogenesis. The subversion of TGF-beta regulation during the processes of carcinogenesis, with particular emphasis on its effects on genetic stability and epithelial to mesenchymal transition (EMT), will also be examined. An understanding of the multiple and complex mechanisms of TGF-beta regulation of epithelial function, and the ultimate loss of TGF-beta function during carcinogenesis, will be critical in the design of novel therapeutic interventions for endocrine-related cancers.

  6. Chronic exposure to combined carcinogens enhances breast cell carcinogenesis with mesenchymal and stem-like cell properties.

    Directory of Open Access Journals (Sweden)

    Lenora Ann Pluchino

    Full Text Available Breast cancer is the most common type of cancer affecting women in North America and Europe. More than 85% of breast cancers are sporadic and attributable to long-term exposure to small quantities of multiple carcinogens. To understand how multiple carcinogens act together to induce cellular carcinogenesis, we studied the activity of environmental carcinogens 4-(methylnitrosamino-1-(3-pyridyl-1-butanone (NNK and benzo[a]pyrene (B[a]P, and dietary carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP using our breast cell carcinogenesis model. Our study revealed, for the first time, that combined NNK and B[a]P enhanced breast cell carcinogenesis chronically induced by PhIP in both non-cancerous and cancerous breast cells. Co-exposure was more potent than sequential exposure to combined NNK and B[a]P followed by PhIP in inducing carcinogenesis. Initiation of carcinogenesis was measured by transient endpoints induced in a single exposure, while progression of carcinogenesis was measured by acquisition of constitutive endpoints in cumulative exposures. Transient endpoints included DNA damage, Ras-Erk-Nox pathway activation, reactive oxygen species elevation, and increased cellular proliferation. Constitutive endpoints included various cancer-associated properties and signaling modulators, as well as enrichment of cancer stem-like cell population and activation of the epithelial-to-mesenchymal transition program. Using transient and constitutive endpoints as targets, we detected that a combination of the green tea catechins ECG and EGCG, at non-cytotoxic levels, was more effective than individual agents in intervention of cellular carcinogenesis induced by combined NNK, B[a]P, and PhIP. Thus, use of combined ECG and EGCG should be seriously considered for early intervention of breast cell carcinogenesis associated with long-term exposure to environmental and dietary carcinogens.

  7. Gastric microbiota and carcinogenesis: the role of non-Helicobacter pylori bacteria: a systematic review

    Directory of Open Access Journals (Sweden)

    Emanuel Dias-Jácome

    Full Text Available Background and aim: Helicobacter pylori is the strongest risk factor for gastric cancer. However, recent advances in DNA sequencing technology have revealed a complex microbial community in the stomach that could also contribute to the development of gastric cancer. The aim of this study was to present recent scientific evidence regarding the role of non-Helicobacter pylori bacteria in gastric carcinogenesis. Methods: A systematic review of original articles published in PubMed in the last ten years related to gastric microbiota and gastric cancer in humans was performed. Results: Thirteen original articles were included. The constitution of gastric microbiota appears to be significantly affected by gastric cancer and premalignant lesions. In fact, differences in gastric microbiota have been documented, depending on Helicobacter pylori status and gastric conditions, such as non-atrophic gastritis, intestinal metaplasia and cancer. Gastric carcinogenesis can be associated with an increase in many bacteria (such as Lactobacillus coleohominis, Klebsiella pneumoniae or Acinetobacter baumannii as well as decrease in others (such as Porphyromonas spp, Neisseria spp, Prevotella pallens or Streptococcus sinensis. However, there is no conclusive data that confirms if these changes in microbiota are a cause or consequence of the process of carcinogenesis. Conclusions: Even though there is limited evidence in humans, microbiota differences between normal individuals, pre-malignant lesions and gastric cancer could suggest a progressive shift in the constitution of gastric microbiota in carcinogenesis, possibly resulting from a complex cross-talk between gastric microbiota and Helicobacter pylori. However, further studies are needed to elucidate the specific role (if any of different microorganisms.

  8. Targeted expression of ornithine decarboxylase antizyme prevents upper aerodigestive tract carcinogenesis in p53-deficient mice

    OpenAIRE

    Feith, David J.; Pegg, Anthony E.; Fong, Louise Y. Y.

    2012-01-01

    Upper aerodigestive tract (UADT) cancers of the oral cavity and esophagus are a significant global health burden, and there is an urgent need to develop relevant animal models to identify chemopreventive and therapeutic strategies to combat these diseases. Antizyme (AZ) is a multifunctional negative regulator of cellular polyamine levels, and here, we evaluate the susceptibility of keratin 5 (K5)-AZ transgenic mice to tumor models that combine chemical carcinogenesis with dietary and genetic ...

  9. Effects of Porcine Pancreatic Enzymes on the Pancreas of Hamsters. Part 2: Carcinogenesis Studies

    OpenAIRE

    2012-01-01

    Context Our previous study suggested that porcine pancreatic extract in hamsters with peripheral insulin resistance, normalizes insulin output, islet size and pancreatic DNA synthetic rate. It also inhibited the growth of human pancreatic cancer cells in nude mice. Objective To examine the potential value of the porcine pancreatic extract in controlling pancreatic carcinogenesis in this model, the present experiment was performed. Design Hamsters were fed a high fat diet and four wee...

  10. In Vivo Testing of Chemopreventive Agents Using the Dog Model of Spontaneous Prostate Carcinogenesis

    Science.gov (United States)

    2005-03-01

    squamous cell or basal cell carcinoma , ing for smoking exposure, non-tumorous lung tissue melanoma); oropharyngeal; hepatocellular carcinoma ; of women...supplementation on cancer incidence in a randomized clinical squamous cell carcinoma of the skin in relation to plasma trial: a summary report of the...invasive carcinoma . In vivo screening of promising chemopreventive agents using the dog model of spontaneous prostate carcinogenesis represents a novel

  11. Epidemiological studies on radiation carcinogenesis in human populations following acute exposure: nuclear explosions and medical radiation

    Energy Technology Data Exchange (ETDEWEB)

    Fabrikant, J.I.

    1981-05-01

    The current knowledge of the carcinogenic effect of radiation in man is considered. The discussion is restricted to dose-incidence data in humans, particularly to certain of those epidemiological studies of human populations that are used most frequently for risk estimation for low-dose radiation carcinogenesis in man. Emphasis is placed solely on those surveys concerned with nuclear explosions and medical exposures. (ACR)

  12. JAK-STAT pathway in carcinogenesis: Is it relevant to cholangiocarcinoma progression?

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The features of JAK-STAT signaling in liver cells are discussed in the current review. The role of this signaling cascade in carcinogenesis is accentuated. The possible involvement of this pathway and alteration of its elements are compared for normal cholangiocytes,cholangiocarcinoma predisposition and development.Prolactin and interleukin-6 are described in detail as the best studied examples. In addition, the non-classical nuclear translocation of cytokine receptors is discussed in terms of its possible implication to cholangiocarcinoma development.

  13. Risks of carcinogenesis from electromagnetic radiation of mobile telephony devices.

    Science.gov (United States)

    Yakymenko, I; Sidorik, E

    2010-07-01

    Intensive implementation of mobile telephony technology in everyday human life during last two decades has given a possibility for epidemiological estimation of long-term effects of chronic exposure of human organism to low-intensive microwave (MW) radiation. Latest epidemiological data reveal a significant increase in risk of development of some types of tumors in chronic (over 10 years) users of mobile phone. It was detected a significant increase in incidence of brain tumors (glioma, acoustic neuroma, meningioma), parotid gland tumor, seminoma in long-term users of mobile phone, especially in cases of ipsilateral use (case-control odds ratios from 1.3 up to 6.1). Two epidemiological studies have indicated a significant increase of cancer incidence in people living close to the mobile telephony base station as compared with the population from distant area. These data raise a question of adequacy of modern safety limits of electromagnetic radiation (EMR) exposure for humans. For today the limits were based solely on the conception of thermal mechanism of biological effects of RF/MW radiation. Meantime the latest experimental data indicate the significant metabolic changes in living cell under the low-intensive (non-thermal) EMR exposure. Among reproducible biological effects of low-intensive MWs are reactive oxygen species overproduction, heat shock proteins expression, DNA damages, apoptosis. The lack of generally accepted mechanism of biological effects of low-intensive non-ionizing radiation doesn't permit to disregard the obvious epidemiological and experimental data of its biological activity. Practical steps must be done for reasonable limitation of excessive EMR exposure, along with the implementation of new safety limits of mobile telephony devices radiation, and new technological decisions, which would take out the source of radiation from human brain.

  14. Type 2 Diabetes Mellitus and Its Association with the Risk of Pancreatic Carcinogenesis: A Review.

    Science.gov (United States)

    Biadgo, Belete; Abebe, Molla

    2016-04-25

    The prevalence of diabetes mellitus (DM) and associated diseases such as cancers are substantially increasing worldwide. About 80% of the patients with pancreatic cancer have glucose metabolism alterations. This suggests an association between type 2 DM and pancreatic cancer risk and progression. There are hypotheses that show metabolic links between the diseases, due to insulin resistance, hyperglycemia, hyperinsulinemia, low grade chronic inflammation, and alteration in the insulin-insulin-like growth factor axis. The use of diabetes medications can influence the extent of carcinogenesis of the pancreas. This study briefly reviews recent literature on investigation of metabolic link of type 2 DM, risk of carcinogenesis of the pancreas and their association, as well as the current understanding of metabolic pathways implicated in metabolism and cellular growth. The main finding of this review, although there are discrepancies, is that according to most research long-term DM does not raise the risk of pancreatic cancer. The longest duration of DM may reflect hypoinsulinemia due to treatment for hyperglycemia, but recent onset diabetes was associated with increased risk for pancreatic cancer due to hyperinsulinemia and hyperglycemia. In conclusion, the review demonstrates that type 2 DM and the duration of diabetes pose a risk for pancreatic carcinogenesis, and that there is biological link between the diseases.

  15. DNA Damage in Inflammation-Related Carcinogenesis and Cancer Stem Cells

    Directory of Open Access Journals (Sweden)

    Shiho Ohnishi

    2013-01-01

    Full Text Available Infection and chronic inflammation have been recognized as important factors for carcinogenesis. Under inflammatory conditions, reactive oxygen species (ROS and reactive nitrogen species (RNS are generated from inflammatory and epithelial cells and result in oxidative and nitrative DNA damage, such as 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG and 8-nitroguanine. The DNA damage can cause mutations and has been implicated in the initiation and/or promotion of inflammation-mediated carcinogenesis. It has been estimated that various infectious agents are carcinogenic to humans (IARC group 1, including parasites (Schistosoma haematobium (SH and Opisthorchis viverrini (OV, viruses (hepatitis C virus (HCV, human papillomavirus (HPV, and Epstein-Barr virus (EBV, and bacterium Helicobacter pylori (HP. SH, OV, HCV, HPV, EBV, and HP are important risk factors for bladder cancer, cholangiocarcinoma, hepatocellular carcinoma, cervical cancer, nasopharyngeal carcinoma, and gastric cancer, respectively. We demonstrated that 8-nitroguanine was strongly formed via inducible nitric oxide synthase (iNOS expression at these cancer sites of patients. Moreover, 8-nitroguanine was formed in Oct3/4-positive stem cells in SH-associated bladder cancer tissues and in Oct3/4- and CD133-positive stem cells in OV-associated cholangiocarcinoma tissues. Therefore, it is considered that oxidative and nitrative DNA damage in stem cells may play a key role in inflammation-related carcinogenesis.

  16. Adiponectin deficiency enhances colorectal carcinogenesis and liver tumor formation induced by azoxymethane in mice

    Institute of Scientific and Technical Information of China (English)

    Tamao Nishihara; Shinji Tamura; Norio Hayashi; Hiroyasu Iishi; Iichiro Shimornura; Miyako Baba; Morihiro Matsuda; Masahiro Inoue; Yasuko Nishizawa; Atsunori Fukuhara; Hiroshi Arald; Shinji Kihara; Tohru Funahashi

    2008-01-01

    AIM: To investigate the causal relationship between hypoadiponectinemia and colorectal carcinogenesis in in vivo experimental model, and to determine the con-tribution of adiponectin deficiency to colorectal cancer development and proliferation. METHODS: We examined the influence of adiponectin deficiency on colorectal carcinogenesis induced by the administration of azoxymethane (AOM) (7.5 mg/kg, in-traperitoneal injection once a week for 8 wk), by using adiponectin-knockout (KO) mice. RESULTS: At 53 wk after the first AOM treatment, KOmice developed larger and histologically more progres-sive colorectal tumors with greater frequency com-pared with wild-type (WT) mice, although the tumor incidence was not different between WT and KO mice. KO mice showed increased cell proliferation of colorec-tal tumor cells, which correlated with the expression levels of cyclooxygenase-2 (COX-2) in the colorectal tumors. In addition, KO mice showed higher incidence and frequency of liver tumors after AOI treatment. Thirteen percent of WT mice developed liver tumors, and these WT mice had only a single tumor. In contrast, 50% of K.O mice developed liver tumors, and 58% of these KO mice had multiple tumors. CONCLUSION: Adiponectin deficiency enhances colorectal carcinogenesis and liver tumor formation induced by AOM in mice. This study strongly suggests that hypoadiponectinemia could be involved in the pathogenesis for colorectal cancer and liver tumor in human subjects.

  17. Evidence for a role of E-cadherin in suppressing liver carcinogenesis in mice and men.

    Science.gov (United States)

    Schneider, Marlon R; Hiltwein, Felix; Grill, Jessica; Blum, Helmut; Krebs, Stefan; Klanner, Andrea; Bauersachs, Stefan; Bruns, Christiane; Longerich, Thomas; Horst, David; Brandl, Lydia; de Toni, Enrico; Herbst, Andreas; Kolligs, Frank T

    2014-08-01

    The cell adhesion molecule E-cadherin has critical functions in development and carcinogenesis. Impaired expression of E-cadherin has been associated with disrupted tissue homeostasis, progression of cancer and a worse patient prognosis. So far, the role of E-cadherin in homeostasis and carcinogenesis of the liver is not well understood. By use of a mouse model with liver-specific deletion of E-cadherin and administration of the carcinogen diethylnitrosamine, we demonstrate that loss of E-cadherin expression in hepatocytes results in acceleration of the growth of hepatocellular carcinoma (HCC). In contrast, liver regeneration is not disturbed in mice lacking E-cadherin expression in hepatocytes. In human HCC, we observed four different expression patterns of E-cadherin. Notably, atypical cytosolic expression of E-cadherin was positively correlated with a poorer patient prognosis. The median overall survival of patients with HCC expressing E-cadherin on the membrane only was 221 weeks (95% confidence interval: 51-391) compared with 131 weeks in patients with cytosolic expression (95% confidence interval: 71-191 weeks; P < 0.05). In conclusion, we demonstrate that impaired expression of E-cadherin promotes hepatocellular carcinogenesis and is associated with a worse prognosis in humans.

  18. Effect of Cu supplementation on genomic instability in chemically-induced mammary carcinogenesis in the rat

    Directory of Open Access Journals (Sweden)

    Bobrowska Barbara

    2011-12-01

    Full Text Available Abstract Backround The aim of the present study was to assess the effect of dietary supplementation (copper or copper and resveratrol on the intensity of carcinogenesis and the frequency of microsatellite instability in a widely used model of mammary carcinogenesis induced in the rat by treatment with 7,12-dimethylbenz[a]anthracene (DMBA. Methods DNA was extracted from rat mammary cancers and normal tisues, amplified by PCR, using different polymorphic DNA markers and the reaction products were analyzed for microsatellite instability. Results It was found that irrespectively of the applied diet there was no inhibition of mammary carcinogenesis in the rats due to DMBA. Besides, in the groups supplemented with Cu (II or Cu (II and resveratrol the tumor formation was clearly accelerated. Unlike the animals that were fed with standard diet, the supplemented rats were characterized by the loss of heterozygosity of microsatellite D3Mgh9 in cancer tumors (by respectively 50 and 40%. When the animals received Cu (II and resveratrol supplemented diet the occurrence of genomic instability was additionally found in their livers in the case of microsatellite D1Mgh6 (which was stable in the animals without dietary supplementation. Conclusions Identification of the underlying mechanisms by which dietary factors affect genomic stability might prove useful in the treatment of mammary cancer as well as in the incorporation of dietary factors into mammary cancer prevention strategies.

  19. Exploration of Multigene, Mulfistep and Multipathway Models of Nasopharyngeal and Colorectal Carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    ZhihuoYin

    2004-01-01

    OBJECTIVE To construct tree models for nasopharyngeal carcinoma (NPC) and colorectal carcinoma (CC) and explore the oncogeneic process of NPC and CC .METHODS Based on the software that Desper et al. developed, tree models were constructed for CC from the comparative genomic hybridization (CGH) data of 118 CC patients and for NPC from the CGH data of 140 southern Chinese patients, respectively. RESULTS Tree models for CC suggested that loss of 18q and gain of 20q were important early events in colorectal carcinogenesis. As changes in -18q occurred prior to those in -17p, a cause-effect relationship might exist between them. Tree models for NPC suggested that loss of 3p was an important early event in nasopharyngeal carcinogenesis, and deletion of 11q, 14q, 16q and 9p were also nonrandom genetic events in carcinogenesis, suggesting that there might be tumor-associated genes existing on these chromosome arms. The tree model also indicated the existence of oncogenes on the short arm of chromosome 12.CONCLUSION Constructing tree models based on the CGH data to demonstrate the initiation and progression of NPC might help elucidate its multigene, multistep and multipathway development. It may provide valuable clues to explore the mechanism of tumorigenesis.

  20. Peroxisome proliferator-activated receptor γ ligands suppress liver carcinogenesis induced by diethylnitrosamine in rats

    Institute of Scientific and Technical Information of China (English)

    Yan-Tong Guo; Xi-Sheng Leng; Tao Li; Jing-Ming Zhao; Xi-Hou Lin

    2004-01-01

    AIM: Peroxisome proliferator-activated receptor γ (PPARγ)is known to regulate growth arrest and terminal differentiation of adipocytes and is used clinically as a new class of antidiabetic drugs. Recently, several studies have reported that treatment of cancer cells with PPARγ ligands could induce cell differentiation and apoptosis, suggesting a potential application as chemopreventive agents against carcinogenesis. In the present study, 3 different kinds of PPARγ ligands were subjected to the experiments to confirm their suppressive effects on liver carcinogenesis.METHODS: Three PPARγ ligands, pioglitazone (Pio) (200 ppm),rosiglitazone (Rosi) (200 ppm), and troglitazone (Tro)(1 000 ppm) were investigated on the induction of the placental form of rat glutathione S-transferase (rGST P)positive foci, a precancerous lesion of the liver, and liver cancer formation using a diethylnitrosamine-induced liver cancer model in Wistar rats, and dose dependency of a PPARγ ligand was also examined.RESULTS: PPARγ ligands reduced the formation of rGST P-positive foci by diethylnitrosamine and induction of liver cancers was also markedly suppressed by a continuous feeding of Pio at 200 ppm.CONCLUSION: PPARγ ligands are potential chemopreventive agents for liver carcinogenesis.

  1. The level of claudin-7 is reduced as an early event in colorectal carcinogenesis

    Directory of Open Access Journals (Sweden)

    Tveit Kjell M

    2011-02-01

    Full Text Available Abstract Background Compromised epithelial barriers are found in dysplastic tissue of the gastrointestinal tract. Claudins are transmembrane proteins important for tight junctions. Claudins regulate the paracellular transport and are crucial for maintaining a functional epithelial barrier. Down-regulation of the oncogenic serine protease, matriptase, induces leakiness in epithelial barriers both in vivo and in vitro. We found in an in-silico search tight co-regulation between matriptase and claudin-7 expression. We have previously shown that the matriptase expression level decreases during colorectal carcinogenesis. In the present study we investigated whether claudin-7 expression is likewise decreased during colorectal carcinogenesis, thereby causing or contributing to the compromised epithelial leakiness of dysplastic tissue. Methods The mRNA level of claudin-7 (CLDN7 was determined in samples from 18 healthy individuals, 100 individuals with dysplasia and 121 colorectal cancer patients using quantitative real time RT-PCR. In addition, immunohistochemical stainings were performed on colorectal adenomas and carcinomas, to confirm the mRNA findings. Results A 2.7-fold reduction in the claudin-7 mRNA level was found when comparing the biopsies from healthy individuals with the biopsies of carcinomas (p claudin-7 mRNA levels were also detected in mild/moderate dysplasia (p Conclusions Our results show that the claudin-7 mRNA level is decreased already as an early event in colorectal carcinogenesis, probably contributing to the compromised epithelial barrier in adenomas.

  2. Dual preventive benefits of iron elimination by desferal in asbestos-induced mesothelial carcinogenesis.

    Science.gov (United States)

    Jiang, Li; Chew, Shan-Hwu; Nakamura, Kosuke; Ohara, Yuuki; Akatsuka, Shinya; Toyokuni, Shinya

    2016-07-01

    Asbestos-induced mesothelial carcinogenesis is currently a profound social issue due to its extremely long incubation period and high mortality rate. Therefore, procedures to prevent malignant mesothelioma in people already exposed to asbestos are important. In previous experiments, we established an asbestos-induced rat peritoneal mesothelioma model, which revealed that local iron overload is a major cause of pathogenesis and that the induced genetic alterations are similar to human counterparts. Furthermore, we showed that oral administration of deferasirox modified the histology from sarcomatoid to the more favorable epithelioid subtype. Here, we used i.p. administration of desferal to evaluate its effects on asbestos-induced peritoneal inflammation and iron deposition, as well as oxidative stress. Nitrilotriacetate was used to promote an iron-catalyzed Fenton reaction as a positive control. Desferal significantly decreased peritoneal fibrosis, iron deposition, and nuclear 8-hydroxy-2'-deoxyguanosine levels in mesothelial cells, whereas nitrilotriacetate significantly increased all of them. Desferal was more effective in rat peritoneal mesothelial cells to counteract asbestos-induced cytotoxicity than in murine macrophages (RAW264.7). Furthermore, rat sarcomatoid mesothelioma cells were more dependent on iron for proliferation than rat peritoneal mesothelial cells. Because inflammogenicity of a fiber is proportionally associated with subsequent mesothelial carcinogenesis, iron elimination from the mesothelial environment can confer dual merits for preventing asbestos-induced mesothelial carcinogenesis by suppressing inflammation and mesothelial proliferation simultaneously.

  3. Causal role of Helicobacter pylori infection and eradication therapy in gastric carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    Masanori Ito; Shinji Tanaka; Tomoari Kamada; Ken Haruma; Kazuaki Chayama

    2006-01-01

    Many epidemiological reports indicate that Helicobacter pylori(H pylori) infection plays an important role in gastric carcinogenesis. Several genetic and epigenetic alterations contribute to the initiation, promotion, and progression of the cancer cells in a multi-step manner.H pyloriis known to induce chronic inflammation in the gastric mucosa. Its products, including superoxides,participate in the DNA damage followed by initiation, and the inflammation-derived cytokines and growth factors contribute to the promotion of gastric carcinogenesis.By eradicating H pylori, gastric inflammation can be cured; the therapy diminishes the levels not only of inflammatory cell infiltration, but also atrophyl intestinal metaplasia in part. A randomized controlled trial revealed that the eradication therapy diminished the gastric cancer prevalence in cases without precancerous conditions. In addition, recent epidemiological studies from Japanese groups demonstrated that the development of gastric cancer, especially of the intestinal type, was decreased by successful eradication therapy, although these were designed in a nonrandomized manner. However, it should be mentioned that endoscopic detection is the only way to evaluate the degree of gastric carcinogenesis. We have reported that the endoscopic and histological morphologies could be modified by eradication therapy and it might contribute to the prevalence of gastric cancer development.Considering the biological nature of cancer cell proliferation, it is considered that a sufficiently long-term follow-up would be essential to discuss the anticancer effect of eradication therapy.

  4. Role of tumor suppressor genes in transplacental lung carcinogenesis.

    Science.gov (United States)

    Rollins, L A; Leone-Kabler, S; O'Sullivan, M G; Miller, M S

    1998-03-01

    Most human cancers involve multiple genetic changes, including activation of oncogenes such as Ki-ras-2 (Kras2) and inactivation of any one of a number of tumor suppressor genes such as p53 and members of the retinoblastoma (Rb) regulatory axis. As part of an ongoing project to determine how in utero exposure to chemical carcinogens affects the molecular pathogenesis of murine lung tumors, the p53 and p16Cdkn2a genes were analyzed by using paraffin-embedded lung tissues from mice treated transplacentally with 3-methylcholanthrene. Single-strand conformation polymorphism analysis of exons 5-8 of the p53 gene, as well as their flanking introns, demonstrated an absence of mutations at this gene locus. However, a genetic polymorphism was identified at nt 708 in intron 4 of the DBA/2 strain of mice 5 bp downstream of a 3' branching-point splice signal. Analysis of exons 1 and 2 of the Cdkn2a gene by single-strand conformation polymorphism and sequence analyses revealed mutations in exon 2 in 7% of the tumors examined. Tumor 23-1 exhibited a CAC-->TAC transition at nt 301 (His74-->Tyr74), and tumor 36-1 exhibited a GGG-->GAG transition at nucleotide 350 (Gly90-->Glu90). Northern blot analysis of 14 of the larger tumors showed a marked decrease in the levels of Rb RNA expression. Immunohistochemical analysis revealed a spectrum of pRb expression, with the smaller adenomas showing moderate numbers of nuclei with heterogeneous staining for pRb in contrast with a highly reduced or near-complete absence of expression in the nuclei of larger tumors with features of adenocarcinomas. The low incidence of mutations at tumor suppressor loci suggested that inactivation of tumor suppressor genes was a late event in murine lung tumor pathogenesis. The identification of both mutations at the Cdkn2a gene locus and reduced levels of Rb expression combined with previous studies demonstrating a high incidence of mutated Kras2 alleles in these tumors implies that alterations of the Rb

  5. Molecular spintronics.

    Science.gov (United States)

    Sanvito, Stefano

    2011-06-01

    The electron spin made its debut in the device world only two decades ago but today our ability of detecting the spin state of a moving electron underpins the entire magnetic data storage industry. This technological revolution has been driven by a constant improvement in our understanding on how spins can be injected, manipulated and detected in the solid state, a field which is collectively named Spintronics. Recently a number of pioneering experiments and theoretical works suggest that organic materials can offer similar and perhaps superior performances in making spin-devices than the more conventional inorganic metals and semiconductors. Furthermore they can pave the way for radically new device concepts. This is Molecular Spintronics, a blossoming research area aimed at exploring how the unique properties of the organic world can marry the requirements of spin-devices. Importantly, after a first phase, where most of the research was focussed on exporting the concepts of inorganic spintronics to organic materials, the field has moved to a more mature age, where the exploitation of the unique properties of molecules has begun to emerge. Molecular spintronics now collects a diverse and interdisciplinary community ranging from device physicists to synthetic chemists to surface scientists. In this critical review, I will survey this fascinating, rapidly evolving, field with a particular eye on new directions and opportunities. The main differences and challenges with respect to standard spintronics will be discussed and so will be the potential cross-fertilization with other fields (177 references).

  6. A Molecular Epidemiologic Case-Case Study of Prostate Cancer

    Science.gov (United States)

    2002-03-01

    Receptor Polymorphism and Prostate Cancer Risk 1 Sara S. Strom 2, Qiang Zhang, Yun Gu, Margaret R. Spitz, Peter T. Scardino 3, Christopher J. Logothetis...Taylor, J. A. Vitamin D receptor polymorphisms and prostate cancer. Molecular Carcinogenesis, 27: 18-23, 2000. 6. Ma, J., Stampfer , M. J., Gann, P. H...Margaret R. Spitz, Richard J. Babaian, Christopher Logothetis, Sara S. Strom, University of Texas M.D. Anderson Cancer Center, Houston, TX; The University

  7. Intranasal Administration of Type V Collagen Reduces Lung Carcinogenesis through Increasing Endothelial and Epithelial Apoptosis in a Urethane-Induced Lung Tumor Model.

    Science.gov (United States)

    Parra, Edwin Roger; Alveno, Renata Antunes; Faustino, Carolina Brito; Corrêa, Paula Yume Sato Serzedello; Vargas, Camilla Mutai; de Morais, Jymenez; Rangel, Maristela Peres; Velosa, Ana Paula Pereira; Fabro, Alexandre Todorovic; Teodoro, Walcy Rosolia; Capelozzi, Vera Luiza

    2016-08-01

    Type V collagen (Col V) is a "minor" component of normal lung extracellular matrix, which is subjected to decreased and abnormal synthesis in human lung infiltrating adenocarcinoma. We previously reported that a direct link between low amounts of Col V and decreased cell apoptosis may favor cancer cell growth in the mouse lung after chemical carcinogenesis. Moreover, this collagen species was able to trigger DNA fragmentation and impair survival of neoplastic cells. In this study, we have extended our investigation with the aim to obtain further evidence that the death induced by Col V-treatment is of the caspase-9 apoptotic type. We used (1) optical and electron microscopy, (2) quantitation of TUNEL-labeled cells and (3) analysis of the expression levels of Col V and selected genes coding for apoptosis-linked factors, by conventional RT-PCR. BALB/c mice were injected intraperitoneally with 1.5 g/kg body weight of urethane. After urethane injection, the animals received intranasal administration of 20 µg/20 µl of Col V every day during 2 months. We report here that Col V treatment was able to determine significant increase in Col V protein and gene expression and in the percentage of TUNEL-positive cells, to up-regulate caspase-9, resulting in low growth of tumor cells. Our data validate chemical carcinogenesis as a suitable "in vivo" model for further and more detailed studies on the molecular mechanisms of the death response induced by Col V in lung infiltrating adenocarcinoma opening new strategies for treatment.

  8. The Matricellular Protein CCN1/Cyr61 Is a Critical Regulator of Sonic Hedgehog in Pancreatic Carcinogenesis*

    Science.gov (United States)

    Haque, Inamul; De, Archana; Majumder, Monami; Mehta, Smita; McGregor, Douglas; Banerjee, Sushanta K.; Van Veldhuizen, Peter; Banerjee, Snigdha

    2012-01-01

    CCN1 is a matricellular protein and a member of the CCN family of growth factors. CCN1 is associated with the development of various cancers including pancreatic ductal adenocarcinoma (PDAC). Our recent studies found that CCN1 plays a critical role in pancreatic carcinogenesis through the induction of EMT and stemness. CCN1 mRNA and protein were detected in the early precursor lesions, and their expression intensified with disease progression. However, biochemical activity and the molecular targets of CCN1 in pancreatic cancer cells are unknown. Here we show that CCN1 regulates the Sonic Hedgehog (SHh) signaling pathway, which is associated with the PDAC progression and poor prognosis. SHh regulation by CCN1 in pancreatic cancer cells is mediated through the active Notch-1. Notably, active Notch-1is recruited by CCN1 in these cells via the inhibition of proteasomal degradation results in stabilization of the receptor. We find that CCN1-induced activation of SHh signaling might be necessary for CCN1-dependent in vitro pancreatic cancer cell migration and tumorigenicity of the side population of pancreatic cancer cells (cancer stem cells) in a xenograft in nude mice. Moreover, the functional role of CCN1 could be mediated through the interaction with the αvβ3 integrin receptor. These extensive studies propose that targeting CCN1 can provide a new treatment option for patients with pancreatic cancer since blocking CCN1 simultaneously blocks two critical pathways (i.e. SHh and Notch1) associated with the development of the disease as well as drug resistance. PMID:23027863

  9. Eugenol precludes cutaneous chemical carcinogenesis in mouse by preventing oxidative stress and inflammation and by inducing apoptosis.

    Science.gov (United States)

    Kaur, Gurpreet; Athar, Mohammad; Alam, M Sarwar

    2010-03-01

    The present study was designed to investigate the protective efficacy of eugenol against skin cancer and probe into the mechanistic aspects. Skin tumors were initiated by applying 160 nmol DMBA and promoted by twice weekly applications of 8.5 nmol TPA for 28 wk. All mice developed tumors by 13 wk of promotion. However, in mice pretreated with 30 microL eugenol, no tumors were detected until 8 wk (following anti-initiation protocol) and until 14 wk (following antipromotion protocol) of tumor promotion. PCNA and TUNEL immunohistochemistry of tumors revealed eugenol to ameliorate cell proliferation and elevate apoptosis respectively. The effect of eugenol was assessed on specific stages of carcinogenesis. Initiation with DMBA led to a significant upregulation of p53 expression with a concomitant increase in p21(WAF1) levels in epidermal cells indicating induction of damage to the DNA. However, pretreatment with eugenol led to overexpression of these genes, which probably helped stimulate apoptosis of the initiated cells. To ascertain the molecular mechanisms implicated in the antitumor promoting activity of eugenol, its effect was investigated on markers of tumor promotion and inflammation: ODC activity and iNOS and COX-2 expression, and on levels of proinflammatory cytokines (IL-6, TNF-alpha, and PGE(2)). Eugenol markedly inhibited all. Eugenol also inhibited the upstream signaling molecule: NF-kappaB, which regulates the expression of these genes. TPA-induced depletion of cutaneous GSH and antioxidant enzymes armory was also precluded by eugenol. From these results, it could be concluded that eugenol markedly protects against chemically induced skin cancer and acts possibly by virtue of its antiproliferative, anti-inflammatory, and antioxidant activities.

  10. SKHIN/Sprd, a new genetically defined inbred hairless mouse strain for UV-induced skin carcinogenesis studies.

    Science.gov (United States)

    Perez, Carlos; Parker-Thornburg, Jan; Mikulec, Carol; Kusewitt, Donna F; Fischer, Susan M; Digiovanni, John; Conti, Claudio J; Benavides, Fernando

    2012-03-01

    Strains of mice vary in their susceptibility to ultra-violet (UV) radiation-induced skin tumors. Some strains of hairless mice (homozygous for the spontaneous Hr(hr) mutation) are particularly susceptible to these tumors. The skin tumors that develop in hairless mice resemble, both at the morphologic and molecular levels, UV-induced squamous cell carcinomas (SCC) and their precursors in human. The most commonly employed hairless mice belong to the SKH1 stock. However, these mice are outbred and their genetic background is not characterized, which makes them a poor model for genetic studies. We have developed a new inbred strain from outbred SKH1 mice that we named SKHIN/Sprd (now at generation F31). In order to characterize the genetic background of this new strain, we genotyped a cohort of mice at F30 with 92 microsatellites and 140 single nucleotide polymorphisms (SNP) evenly distributed throughout the mouse genome. We also exposed SKHIN/Sprd mice to chronic UV irradiation and showed that they are as susceptible to UV-induced skin carcinogenesis as outbred SKH1 mice. In addition, we proved that, albeit with low efficiency, inbred SKHIN/Sprd mice are suitable for transgenic production by classical pronuclear microinjection. This new inbred strain will be useful for the development of transgenic and congenic strains on a hairless inbred background as well as the establishment of syngeneic tumor cell lines. These new tools can potentially help elucidate a number of features of the cutaneous response to UV irradiation in humans, including the effect of genetic background and modifier genes.

  11. Chemopreventive effect of Korean Angelica root extract on TRAMP carcinogenesis and integrative "omic" profiling of affected neuroendocrine carcinomas.

    Science.gov (United States)

    Zhang, Jinhui; Wang, Lei; Zhang, Yong; Li, Li; Tang, Suni; Xing, Chengguo; Kim, Sung-Hoon; Jiang, Cheng; Lü, Junxuan

    2015-12-01

    Angelica gigas Nakai (AGN) root ethanol extract exerts anti-cancer activity in several allograft and xenograft models. Here we examined its chemopreventive efficacy through gavage administration against primary carcinogenesis in the transgenic adenocarcinoma of mouse prostate (TRAMP) model. Male C57BL/6 TRAMP mice and wild type littermates were given a daily gavage (5 mg/mouse, Monday-Friday) of AGN or vehicle, beginning at 8 wk of age (WOA). All mice were terminated at 24 WOA, unless earlier euthanasia was necessitated by large tumors. Whereas AGN-treated TRAMP mice decreased dorsolateral prostate lesion growth by 30% (P = 0.009), they developed fewer and smaller neuroendocrine-carcinomas (NE-Ca) (0.12 g/mouse) than vehicle-treated counterparts (0.81 g/mouse, P = 0.037). We analyzed the proteome and transcriptome of banked NE-Ca to gain molecular insights. Angiogenesis-antibody array detected a substantial reduction in AGN-treated NE-Ca of basic fibroblast growth factor (FGF2), an angiogenesis stimulator. iTRAQ proteomics plus data mining suggested changes of genes upstream and downstream of FGF2 functionally consistent with AGN inhibiting FGF2/FGFR1 signaling at different levels of the transduction cascade. Moreover, AGN upregulated mRNA of genes related to immune responses, restored expression of many tumor suppressor genes, and prostate function and muscle differentiation genes. On the other hand, AGN down-regulated mRNA of genes related to neuron signaling, oncofetal antigens, inflammation, and mast cells, Wnt signaling, embryonic morphogenesis, biosynthesis, cell adhesion, motility, invasion, and angiogenesis. These changes suggest not only multiple cancer cell targeting actions of AGN but also impact on the tumor microenvironments such as angiogenesis, inflammation, and immune surveillance.

  12. Analysis of Inactivation of hMLH1 by Promoter Hypermethylation and Microsatellite Instability in Gastric Carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    Dong Wang; Yao Xu; Xin Geng; Weiming Zhang

    2006-01-01

    BJECTIVE To study the microsatellite instability (MSI) and methylation state of the hMLH1 gene promoter and their mechanisms underlying the development of gastric cancer.METHODS Forty-one gastric cancer samples were obtained from patients undergoing surgery and 46 chronic atrophic gastritis tissues with dysplasia or intestinal metaplasia (IM) were obtained from patients undergoing gastro-endoscopy. Fourteen normal gastric mucosal samples were used as controls. Genomic DNA was extracted from the samples and 5 microsatellite markers were used to measure MSI. Methylationspecific PCR (MSP) was used to screen the methylation state of the samples. DNA sequencing and immunohistochemistry were performed to verify the results.RESULTS MSI was identified in 22 out of the 41 (53.7%) gastric cancers,of which 8 cases showed high-level MSI (2 or more loci altered) and 14showed low-level MSI (1 locus altered). MSI was also detected in 12 out of 46 (26.1%) pre-cancerous lesions of the stomach, whereas it was not seen in the normal tissue. Moreover, hMLH1 hypermethylation was detected in 17 out of the 41 (41.5%) gastric cancers, 9 out of the 46 (19.6%)pre-cancerous lesions and O out of the 14 normal tissue. Significant differences in frequency of MSI and hMLH1 promoter methylation were observed among gastric cancers, precancerous lesions and normal gastric tissue. Gastric samples with MSI had a tendency to be hypermethylated in the hMLH1 promoter. DNA sequencing and immunohistochemistry results also confirmed that hMLH1 promoter methylation could lead to loss of the hMLH1 protein and gene silence which sequentely resulted in gene mismatch and MSI.CONCLUSION Accumulation of MSI and hMLH1 promoter methylation may be important early molecular events during gastric carcinogenesis and may contribute to the acquisition of a transformed cell phenotype and the development of gastric cancer.

  13. Molecular Biology of Esophageal Cancer

    Institute of Scientific and Technical Information of China (English)

    HuanXi; JanBrabender; RalfMetzger; PaulM.Schneider

    2004-01-01

    There have been many new developments in our understanding of esophageal carcinoma biology over the past several years. Information regarding both of the major forms of this disease, adenocarcinoma and squamous cell carcinoma, has accumulated in conjunction with data on precursor conditions such as Barrett's esophagus. Interesting and promising findings have included overexpression of proto-oncogenes,loss of heterozygosity at multiple chromosomal loci, tumor suppressor gene inactivation, epigenetic silencing by DNA methylation, and mutations and deletions involving the tumor suppressor gene p53. Important cancer pathways, the cyclin kinase inhibitor cascade and the DNA mismatch repair process, implicated in the genesis of multiple tumor types have also been inculpated in esophageal carcinogenesis. Alterations in the p16 and p15 cyclin kinase inhibitors including point mutations and homozygous deletions have been reported in primary esophageal tumors. Further developments in the field of molecular carcinogenesis of esophageal malignancies promise to yield improvements in prevention, early detection, prognostic categorization, and perhaps gene-based therapy of this deadly disease.

  14. Metallomics: the concept and methodology.

    Science.gov (United States)

    Mounicou, Sandra; Szpunar, Joanna; Lobinski, Ryszard

    2009-04-01

    The emerging field of metallomics refers to the entirety of research activities aimed at the understanding of the molecular mechanisms of metal-dependent life processes. This critical review discusses the concept of metallomics with a focus on analytical techniques and methods for the probing of interactions between metal ions and the organism's genome and the derived -omes: proteome and metabolome. Particular attention is paid to the in vivo screening for the native metal-protein and metal-metabolite complexes by hyphenated techniques that combine a high-resolution separation technique (gel electrophoresis, chromatography or capillary electrophoresis) with sensitive elemental (inductively coupled plasma, ICP) or molecular (electrospray or MALDI) mass spectrometric detection. The contribution of bioinformatics to the prediction of metal-binding sequences in proteins and the role of molecular biology approaches for the detection of metal-dependent genes, proteins and metabolites are highlighted (115 references).

  15. Explanation of the mechanism of carcinogenesis and syntheses of anticancer agents with high selectivity

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In 1979, the mechanism of chemical carcinogenesis, a challenging and difficult scientific problem pending for a number of years, was explained by Dai Qianhuan. The mechanism named di-region theory predicted that a carcinogen always metabolizes to form a special bi-functional alkylating agent. This agent induces cross-linkages between the complementary base pairs in DNA and switches on initial mutageneses in genomes including point and frameshift mutations. This, in turn, induces further deep mutageneses including the production of various chimeric chromosomes, deletions and other aberrations found in genomes. In the end this initiates carcinogenesis of the whole cell through the reverse transcription mechanism after a lengthy incubation period. Recently, this laboratory has verified that physical carcinogenesis, including the oncogenesis induced by radiation and asbestos as well as the carcinogenesis induced by endogenous factors such as estrogen or diethylstilbestrol switch on carcinogenesis by inducing the formation of cross-linkages between the complementary base pairs in DNA. Di-region theory has now been supported by many experimental observations such as mutational spectra of various carcinogens. The potential for carcinogenesis, teratogenesis, sterility and mutagenesis lumped together as genetic toxicity appears to originate almost uniformly from the cross-linking between complementary bases, i.e. malignant cross-linking, which is in accordance with di-region theory. Other forms of cross-linking between non-complementary bases, benign cross-linkings, show bi-functional alkylation anticancer activity but lack genetic toxicity. The predictable design and synthesis of a high selectivity anticancer agent with high efficacy and low genetic toxicity, a goal long pursued in cancer chemotherapy, have been realized for the first time in this laboratory by inhibiting malignant and heightening benign cross-linking using the principles of di-region theory. A series of

  16. Histological and ultrastructural changes induced by selenium in early experimental gastric carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    Yan-Ping Su; Jun-Min Tang; Yan Tang; Hui-Ying Gao

    2005-01-01

    AIM: To investigate the effect and significance of selenium in early experimental gastric carcinogenesis.METHODS: Weaning male Wistar rats were divided randomly into normal control group, experiment control group, low selenium (2 mg/L) group and high selenium (4 mg/L) group. Wistar rat gastric carcinogenesis was induced by N-methyl-N-nitro-N-nitroso guanidine (MNNG) (20 mg/kg) gavage daily for 10 d. Na2SeO3 was given by piped drinking 1 wk prior to MNNG gavage. The rats were killed at the 43rd wk. The surface characteristics of gastric mucosa were observed with naked eyes. Histopathologic changes of rat gastric mucosa were observed by HE staining and AB-PAS methods. The changes of cellular ultrastructure were observed under transmission electron microscope. Statistical analysis was carried out by SPSS.RESULTS: The incidence rate of gastric mucosa erosion,hemorrhage and intestinal metaplasia was 0, 45.5%,66.7%, and 92.9%, respectively (92.9% vs45.5%, P<0.05)in the normal control group, experiment control group,low selenium group, and high selenium group. Leiomyoma formed in the process of inducement of rat gastric carcinoma. Dietary Na2SeO3 (2 and 4 mg/L) slightly increased the incidence rate of leiomyoma (0, 23%, 46.6%, and 46.6%). gastric mucosa did not change in the course of rat gastric carcinogenesis. Dietary Na2SeO3 by pipe drinking could expand the intracellular secretory canaliculus of parietal cells and increase the number of endocrine cells and lysosomes.CONCLUSION: Dietary Na2SeO3 by pipe drinking aggravates gastric erosion, hemorrhage and promotes intestinal metaplasia of gastric mucosa. The mechanism may be related with the function of parietal cells.

  17. Long non-coding RNA HOTAIR promotes carcinogenesis and invasion of gastric adenocarcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Na Keum; Lee, Jung Hwa; Park, Chan Hyuk; Yu, Dayeon; Lee, Yong Chan [Division of Gastroenterology, Department of Internal Medicine, Yonsei Institute of Gastroenterology, Yonsei University College of Medicine, Seoul (Korea, Republic of); Cheong, Jae-Ho; Noh, Sung Hoon [Department of Surgery, Yonsei University College of Medicine (Korea, Republic of); Lee, Sang Kil, E-mail: sklee@yuhs.ac [Division of Gastroenterology, Department of Internal Medicine, Yonsei Institute of Gastroenterology, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2014-08-22

    Highlights: • HOTAIR expression was tested in fifty patients with gastric cancer. • Cell proliferation was measured after HOTAIR silencing in gastric cancer cell line. • siRNA–HOTAIR suppresses cell invasiveness and capacity of migration. • Knock down of HOTAR leads to decreased expression of EMT markers. • Inhibition of HOTAIR induces apoptosis and cell cycle arrest. - Abstract: Gastric cancer is one of the major causes of cancer death worldwide; however, the mechanism of carcinogenesis is complex and poorly understood. Long non-coding RNA HOTAIR (HOX transcript antisense RNA) recently emerged as a promoter of metastasis in various cancers including gastric cancer. Here we investigated the impact of HOTAIR on apoptosis, cell proliferation and cell cycle to dissect the carcinogenesis of gastric cancer. We examined the mechanism of invasion and metastasis and analyzed the clinical significance of HOTAIR. Downregulation of HOTAIR was confirmed by two different siRNAs. The expression of HOTAIR was significantly elevated in various gastric cancer cell lines and tissues compared to normal control. si-HOTAIR significantly reduced viability in MKN 28, MKN 74, and KATO III cells but not in AGS cells. si-HOTAIR induced apoptosis in KATO III cells. Lymphovascular invasion and lymph node metastasis were more common in the high level of HOTAIR group. si-HOTAIR significantly decreased invasiveness and migration. si-HOTAIR led to differential expression of epithelial to mesenchymal transition markers. We found that HOTAIR was involved in inhibition of apoptosis and promoted invasiveness, supporting a role for HOTAIR in carcinogenesis and progression of gastric cancer.

  18. Differences in proximal (cardia) versus distal (antral) gastric carcinogenesis via retinoblastoma pathway

    Institute of Scientific and Technical Information of China (English)

    Christian Gulmann; Helen Hegarty; Antoinette Grace; Mary Leader; Stephen Patchett; Elaine Kay

    2004-01-01

    AIM: Disruption of cell cycle regulation is a critical event in carcinogenesis, and alteration of the retinoblastoma (pRb)tumour suppressor pathway is frequent. The aim of this study was to compare alterations in this pathway in proximal and distal gastric carcinogenesis in an effort to explain the observed striking epidemiological differences.METHODS: Immunohistochemistry was performed to investigate expression of p16 and pRb in the following groups of both proximal (cardia) and distal (antral) tissue samples: (a) biopsies showing normal mucosa, (b) biopsies showing intestinal metaplasia and, (c) gastric cancer resection specimens including uninvolved mucosa and tumour.RESULTS: In the antrum there were highly significant trends for increased p16 expression with concomitant (and in the group of carcinomas inversely proportional)decreased pRb expression from normal mucosa to intestinal metaplasia to uninvolved mucosa (from cancer resections)to carcinoma. In the cardia, there were no differences in p16 expression between the various types of tissue samples whereas pRb expression was higher in normal mucosa compared with intestinal metaplasia and tissue from cancer resections.CONCLUSION: Alterations in the pRb pathway appear to play a more significant role in distal gastric carcinogenesis.Tt may be an early event in the former location since the trend towards p16 overexpression with concomitant pRb underexpression was seen as early as between normal mucosa and intestinal metaplasia. Importantly, the marked differences in expression of pRb and p16 between the cardia and antrum strongly support the hypothesis that tumours of the two locations are genetically different which may account for some of the observed epidemiological differences.

  19. The Impact of Neural Stem Cell Biology on CNS Carcinogenesis and Tumor Types

    Directory of Open Access Journals (Sweden)

    K. M. Kurian

    2011-01-01

    Full Text Available The incidence of gliomas is on the increase, according to epidemiological data. This increase is a conundrum because the brain is in a privileged protected site behind the blood-brain barrier, and therefore partially buffered from environmental factors. In addition the brain also has a very low proliferative potential compared with other parts of the body. Recent advances in neural stem cell biology have impacted on our understanding of CNS carcinogenesis and tumor types. This article considers the cancer stem cell theory with regard to CNS cancers, whether CNS tumors arise from human neural stem cells and whether glioma stem cells can be reprogrammed.

  20. Myenteric denervation in gastric carcinogenesis: differential modulation of nitric oxide and annexin-A1

    OpenAIRE

    2012-01-01

    This study evaluated the properties of endogenous nitric oxide synthases (NOS) and annexin-A1 (ANXA1) and determined how they can be exploited in the N-methyl-N-nitro-N-nitrosoguanidine (MNNG)-induced gastric carcinogenesis and myenteric denervation model. Male Wistar rats were treated with MNNG and/or aminoguanidine (AG) for 20 weeks. In another set of experiments, rats with nondenervated and denervated stomachs were treated with MNNG or water for 28 weeks. Fragments of the pyloric region we...

  1. Environmental pollution and DNA methylation: carcinogenesis, clinical significance, and practical applications.

    Science.gov (United States)

    Cao, Yi

    2015-09-01

    Environmental pollution is one of the main causes of human cancer. Exposures to environmental carcinogens result in genetic and epigenetic alterations which induce cell transformation. Epigenetic changes caused by environmental pollution play important roles in the development and progression of environmental pollution-related cancers. Studies on DNA methylation are among the earliest and most conducted epigenetic research linked to cancer. In this review, the roles of DNA methylation in carcinogenesis and their significance in clinical medicine were summarized, and the effects of environmental pollutants, particularly air pollutants, on DNA methylation were introduced. Furthermore, prospective applications of DNA methylation to environmental pollution detection and cancer prevention were discussed.

  2. High Dietary Salt Intake Exacerbates Helicobacter pylori-Induced Gastric Carcinogenesis

    OpenAIRE

    Gaddy, Jennifer A.; Radin, Jana N.; Loh, John T.; Zhang, Feng; Washington, M. Kay; Peek, Richard M.; Algood, Holly M. Scott; Cover, Timothy L.

    2013-01-01

    Persistent colonization of the human stomach with Helicobacter pylori is a risk factor for gastric adenocarcinoma, and H. pylori-induced carcinogenesis is dependent on the actions of a bacterial oncoprotein known as CagA. Epidemiological studies have shown that high dietary salt intake is also a risk factor for gastric cancer. To investigate the effects of a high-salt diet, we infected Mongolian gerbils with a wild-type (WT) cagA+ H. pylori strain or an isogenic cagA mutant strain and main...

  3. Progression of diethylnitrosamine-induced hepatic carcinogenesis in carnitine-depleted rats

    Institute of Scientific and Technical Information of China (English)

    Salim S Al-Rejaie; Abdulaziz M Aleisa; Abdulaziz A Al-Yahya; Saleh A Bakheet; Abdulmalik Alsheikh; Amal G Fatani; Othman A Al-Shabanah; Mohamed M Sayed-Ahmed

    2009-01-01

    AIM: To investigate whether carnitine deficiency is a risk factor during the development of diethylnitrosamine (DENA)-induced hepatic carcinogenesis.METHODS: A total of 60 male Wistar albino rats were divided into six groups with 10 animals in each group. Rats in group 1 (control group) received a single intraperitoneal (i.p.) injection of normal saline.Animals in group 2 (carnitine-supplemented group) were given L-carnitine (200 mg/kg per day) in drinking water for 8 wk. Animals in group 3 (carnitine-depleted group) were given D-carnitine (200 mg/kg per day) and mildronate (200 mg/kg per day) in drinking water for 8 wk. Rats in group 4 (DENA group) were injected with a single dose of DENA (200 mg/kg, i.p.) and 2 wk later received a single dose of carbon tetrachloride (2 mL/kg) by gavage as 1:1 dilution in corn oil. Animals in group 5 (DENA-carnitine depleted group) received the same treatment as group 3 and group 4. Rats in group 6 (DENA-carnitine supplemented group) received the same treatment as group 2 and group 4.RESULTS: Administration of DENA resulted in a significant increase in alanine transaminase (ALT),gamma-glutamyl t ransferase (G-GT) , alkal ine phosphatase (ALP), total bilirubin, thiobarbituric acid reactive substances (TBARS) and total nitrate/nitrite (NOx) and a significant decrease in reduced glutathione (GSH), glutathione peroxidase (GSHPx),catalase (CAT) and total carnitine content in liver tissues. In the carnitine-depleted rat model, DENA induced a dramatic increase in serum ALT, G-GT, ALP and total bilirubin, as well as a progressive reduction in total carnitine content in liver tissues. Interestingly,L-carnitine supplementation resulted in a complete reversal of the increase in liver enzymes, TBARS and NOx, and a decrease in total carnitine, GSH, GSHPx,and CAT induced by DENA, compared with the control values. Histopathological examination of liver tissues confirmed the biochemical data, where L-carnitine prevented DENA-induced hepatic

  4. A mathematical model of radiation carcinogenesis with induction of genomic instability and cell death.

    Science.gov (United States)

    Ohtaki, M; Niwa, O

    2001-11-01

    We developed a mathematical model of carcinogenesis that incorporates genomic instability, a feature characterized by long-term destabilization of the genome in irradiated cells that leads to an increase in cancer risk in the exposed individuals at the cancer-prone age. This model also considers the induction of cell death, another important effect of radiation on cells. It is assumed that cell killing by radiation may occur at all stages of the carcinogenic process. The resulting model can explain not only the paradoxical relationship between low mutation rates and high cancer incidence but also the low-order dose-response relationship of cancer risk.

  5. Identification problem for stochastic models with application to carcinogenesis, cancer detection and radiation biology

    Directory of Open Access Journals (Sweden)

    L. G. Hanin

    2002-01-01

    Full Text Available A general framework for solving identification problem for a broad class of deterministic and stochastic models is discussed. This methodology allows for a unified approach to studying identifiability of various stochastic models arising in biology and medicine including models of spontaneous and induced Carcinogenesis, tumor progression and detection, and randomized hit and target models of irradiated cell survival. A variety of known results on parameter identification for stochastic models is reviewed and several new results are presented with an emphasis on rigorous mathematical development.

  6. Serial concept maps: tools for concept analysis.

    Science.gov (United States)

    All, Anita C; Huycke, LaRae I

    2007-05-01

    Nursing theory challenges students to think abstractly and is often a difficult introduction to graduate study. Traditionally, concept analysis is useful in facilitating this abstract thinking. Concept maps are a way to visualize an individual's knowledge about a specific topic. Serial concept maps express the sequential evolution of a student's perceptions of a selected concept. Maps reveal individual differences in learning and perceptions, as well as progress in understanding the concept. Relationships are assessed and suggestions are made during serial mapping, which actively engages the students and faculty in dialogue that leads to increased understanding of the link between nursing theory and practice. Serial concept mapping lends itself well to both online and traditional classroom environments.

  7. Hyaluronic Acid--an "Old" Molecule with "New" Functions: Biosynthesis and Depolymerization of Hyaluronic Acid in Bacteria and Vertebrate Tissues Including during Carcinogenesis.

    Science.gov (United States)

    Tsepilov, R N; Beloded, A V

    2015-09-01

    Hyaluronic acid is an evolutionarily ancient molecule commonly found in vertebrate tissues and capsules of some bacteria. Here we review modern data regarding structure, properties, and biological functions of hyaluronic acid in mammals and Streptococcus spp. bacteria. Various aspects of biogenesis and degradation of hyaluronic acid are discussed, biosynthesis and degradation metabolic pathways for glycosaminoglycan together with involved enzymes are described, and vertebrate and bacterial hyaluronan synthase genes are characterized. Special attention is given to the mechanisms underlying the biological action of hyaluronic acid as well as the interaction between polysaccharide and various proteins. In addition, all known signaling pathways involving hyaluronic acid are outlined. Impaired hyaluronic acid metabolism, changes in biopolymer molecular weight, hyaluronidase activity, and enzyme isoforms often accompany carcinogenesis. The interaction between cells and hyaluronic acid from extracellular matrix that may be important during malignant change is discussed. An expected role for high molecular weight hyaluronic acid in resistance of naked mole rat to oncologic diseases and the protective role of hyaluronic acid in bacteria are discussed.

  8. A importância do gene p53 na carcinogênese humana The importance of the p53 gene in human carcinogenesis

    Directory of Open Access Journals (Sweden)

    Agnes C. Fett-Conte

    2002-04-01

    Full Text Available Existem várias razões que justificam o título de "guardião do genoma" do gene P53. Seu envolvimento, direto ou indireto, tem sido observado na etiopatogenia de praticamente todas as neoplasias humanas, incluindo as leucemias e linfomas. Conhecer seus mecanismos de ação é fundamental para compreender os aspectos moleculares da carcinogênese. O presente trabalho apresenta uma revisão sobre as características deste gene e sua importância no diagnóstico, prognóstico e terapêutica, o que faz dele um alvo em potencial das estratégias de terapia gênica.There are several reasons which justify the name of 'guardian of the genome' given to the P53 gene. Its involvement either directly or indirectly has been observed in the pathology of practically all human neoplasias, including leukemia and lymphomas. Knowledge of its mechanisms of action is fundamental to understand molecular aspects of carcinogenesis. This work presents a revision of the characteristics of this gene and its importance in the diagnosis, prognosis and treatment and why this makes it a potential target for gene therapy strategies.

  9. Radiation carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Fry, R.J.M.

    1976-01-01

    The risk of iatrogenic tumors with radiation therapy is so outweighed by the benefit of cure that estimates of risk have not been considered necessary. However, with the introduction of chemotherapy, combined therapy, and particle radiation therapy, the comparative risks should be examined. In the case of radiation, total dose, fractionation, dose rate, dose distribution, and radiation quality should be considered in the estimation of risk. The biological factors that must be considered include incidence of tumors, latent period, degree of malignancy, and multiplicity of tumors. The risk of radiation induction of tumors is influenced by the genotype, sex, and age of the patient, the tissues that will be exposed, and previous therapy. With chemotherapy the number of cells at risk is usually markedly higher than with radiation therapy. Clearly the problem of the estimation of comparative risks is complex. This paper presents the current views on the comparative risks and the importance of the various factors that influence the estimation of risk.

  10. Transforming growth factor-β1 in carcinogenesis, progression, and therapy in cervical cancer.

    Science.gov (United States)

    Zhu, Haiyan; Luo, Hui; Shen, Zhaojun; Hu, Xiaoli; Sun, Luzhe; Zhu, Xueqiong

    2016-06-01

    Transforming growth factor β1 (TGF-β1) is a multifunctional cytokine that plays important roles in cervical tumor formation, invasion, progression, and metastasis. TGF-β1 functions as a tumor inhibitor in precancerous lesions and early stage cancers of cervix whereas as a tumor promoter in later stage. This switch from a tumor inhibitor to a tumor promoter might be due to various alterations in TGF-β signaling pathway, such as mutations or loss of expression of TGF-β receptors and SMAD proteins. Additionally, the oncoproteins of human papillomaviruses have been shown to stimulate TGF-β1 expression, which in turn suppresses host immune surveillance. Thus, in addition to driving tumor cell migration and metastasis, TGF-β1 is believed to play a key role in promoting human papillomavirus infection by weakening host immune defense. In this article, we will discuss the role of TGF-β1 in the expression, carcinogenesis, progression, and therapy in cervical cancers. A better understanding of this cytokine in cervical carcinogenesis is essential for critical evaluation of this cytokine as a potential prognostic marker and therapeutic target.

  11. Cell Cycle Phase Abnormalities Do Not Account for Disordered Proliferation in Barrett's Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Pierre Lao-Sirieix

    2004-11-01

    Full Text Available Barrett's esophagus (BE epithelium is the precursor lesion for esophageal adenocarcinoma. Cell cycle proteins have been advocated as biomarkers to predict the malignant potential in BE. However, whether disruption of the cell cycle plays a causal role in Barrett's carcinogenesis is not clear. Specimens from the Barrett's dysplasia—carcinoma sequence were immunostained for cell cycle phase markers (cyclin D1 for G1; cyclin A for S, G2, and M; cytoplasmic cyclin B1 for G2; and phosphorylated histone 3 for M phase and expressed as a proportion of proliferating cells. Flow cytometric analysis of the cell cycle phase of prospective biopsies was also performed. The proliferation status of nondysplastic BE was similar to gastric antrum and D2, but the proliferative compartment extended to the luminal surface. In dysplastic samples, the number of proliferating cells correlated with the degree of dysplasia (P < .001. The overall levels of cyclins A and B1 correlated with the degree of dysplasia (P < .001. However, the cell cycle phase distribution measured with both immunostaining and flow cytometry was conserved during all stages of BE, dysplasia, and cancer. Hence, the increased proliferation seen in Barrett's carcinogenesis is due to abnormal cell cycle entry or exit, rather than a primary abnormality within the cell cycle.

  12. [In vitro and in vivo effects of mango pulp (Mangifera indica cv. Azucar) in colon carcinogenesis].

    Science.gov (United States)

    Corrales-Bernal, Andrea; Amparo Urango, Luz; Rojano, Benjamín; Maldonado, Maria Elena

    2014-03-01

    Mango pulp contains ascorbic acid, carotenoids, polyphenols, terpenoids and fiber which are healthy and could protect against colon cancer. The aim of this study was to evaluate the antiproliferative and preventive capacity of an aqueous extract of Mangifera indica cv. Azúcar on a human colon adenocarcinoma cell line (SW480) and in a rodent model of colorectal cancer, respectively. The content of total phenolics, flavonoids and carotenoids were also analyzed in the extract. SW480 cell growth was inhibited in a dose and time dependent manner by 22.3% after a 72h exposure to the extract (200 µg/ mL). Colon carcinogenesis was initiated in Balb/c mice by two intra-peritoneal injections of azoxymethane (AOM) at the third and fourth week of giving mango in drinking water (0.3%, 0.6%, 1.25%). After 10 weeks of treatment, in the colon of mice receiving 0.3% mango, aberrant crypt foci formation was inhibited more than 60% (p=0,05) and the inhibition was dose-dependent when compared with controls receiving water. These results show that mango pulp, a natural food, non toxic, part of human being diet, contains bioactive compounds able to reduce growth of tumor cells and to prevent the appearance of precancerous lesions in colon during carcinogenesis initiation.

  13. Preventive Effects of Fermented Brown Rice and Rice Bran against Prostate Carcinogenesis in TRAP Rats

    Directory of Open Access Journals (Sweden)

    Toshiya Kuno

    2016-07-01

    Full Text Available Fermented brown rice and rice bran with Aspergillus oryzae (FBRA is considered to have the potential to prevent chemically-induced carcinogenesis in multiple organs of rodents. In the present study, we evaluated the possible chemopreventive effects of FBRA against prostate tumorigenesis. Six-week-old male rats of the transgenic rat for adenocarcinoma of prostate (TRAP strain were fed diets containing 5% or 10% FBRA for 15 weeks. Animals were sacrificed at 21 weeks of age, and the ventral and lateral prostate were removed for histopathological evaluation and immunoblot analyses. FBRA decreased the incidence of adenocarcinoma in the lateral prostate and suppressed the progression of prostate carcinogenesis. Treatment with FBRA induced apoptosis and inhibited cell proliferation in histologically high-grade prostatic intraepithelial neoplasias. Phospho-AMP-activated kinase α (Thr172 was up-regulated in the prostate of rats fed the diet supplemented with FBRA. These results indicate that FBRA controls tumor growth by activating pathways responsive to energy deprivation and suggest that FBRA has translational potential for the prevention of human prostate cancer.

  14. Alterations of global histone H4K20 methylation during prostate carcinogenesis

    Directory of Open Access Journals (Sweden)

    Behbahani Turang E

    2012-03-01

    Full Text Available Abstract Background Global histone modifications have been implicated in the progression of various tumour entities. Our study was designed to assess global methylation levels of histone 4 lysine 20 (H4K20me1-3 at different stages of prostate cancer (PCA carcinogenesis. Methods Global H4K20 methylation levels were evaluated using a tissue microarray in patients with clinically localized PCA (n = 113, non-malignant prostate disease (n = 27, metastatic hormone-naive PCA (mPCA, n = 30 and castration-resistant PCA (CRPC, n = 34. Immunohistochemistry was performed to assess global levels of H4K20 methylation levels. Results Similar proportions of the normal, PCA, and mPCA prostate tissues showed strong H4K20me3 staining. CRPC tissue analysis showed the weakest immunostaining levels of H4K20me1 and H4K20me2, compared to other prostate tissues. H4K20me2 methylation levels indicated significant differences in examined tissues except for normal prostate versus PCA tissue. H4K20me1 differentiates CRPC from other prostate tissues. H4K20me1 was significantly correlated with lymph node metastases, and H4K20me2 showed a significant correlation with the Gleason score. However, H4K20 methylation levels failed to predict PSA recurrence after radical prostatectomy. Conclusions H4K20 methylation levels constitute valuable markers for the dynamic process of prostate cancer carcinogenesis.

  15. ICRP Publication 131: Stem cell biology with respect to carcinogenesis aspects of radiological protection.

    Science.gov (United States)

    Hendry, J H; Niwa, O; Barcellos-Hoff, M H; Globus, R K; Harrison, J D; Martin, M T; Seed, T M; Shay, J W; Story, M D; Suzuki, K; Yamashita, S

    2016-06-01

    Current knowledge of stem cell characteristics, maintenance and renewal, evolution with age, location in 'niches', and radiosensitivity to acute and protracted exposures is reviewed regarding haematopoietic tissue, mammary gland, thyroid, digestive tract, lung, skin, and bone. The identity of the target cells for carcinogenesis continues to point to the more primitive and mostly quiescent stem cell population (able to accumulate the protracted sequence of mutations necessary to result in malignancy), and, in a few tissues, to daughter progenitor cells. Several biological processes could contribute to the protection of stem cells from mutation accumulation: (1) accurate DNA repair; (2) rapid induced death of injured stem cells; (3) retention of the intact parental strand during divisions in some tissues so that mutations are passed to the daughter differentiating cells; and (4) stem cell competition, whereby undamaged stem cells outcompete damaged stem cells for residence in the vital niche. DNA repair mainly operates within a few days of irradiation, while stem cell replications and competition require weeks or many months depending on the tissue type. This foundation is used to provide a biological insight to protection issues including the linear-non-threshold and relative risk models, differences in cancer risk between tissues, dose-rate effects, and changes in the risk of radiation carcinogenesis by age at exposure and attained age.

  16. A20 restricts wnt signaling in intestinal epithelial cells and suppresses colon carcinogenesis.

    Directory of Open Access Journals (Sweden)

    Ling Shao

    Full Text Available Colon carcinogenesis consists of a multistep process during which a series of genetic and epigenetic adaptations occur that lead to malignant transformation. Here, we have studied the role of A20 (also known as TNFAIP3, a ubiquitin-editing enzyme that restricts NFκB and cell death signaling, in intestinal homeostasis and tumorigenesis. We have found that A20 expression is consistently reduced in human colonic adenomas than in normal colonic tissues. To further investigate A20's potential roles in regulating colon carcinogenesis, we have generated mice lacking A20 specifically in intestinal epithelial cells and interbred these with mice harboring a mutation in the adenomatous polyposis coli gene (APC(min. While A20(FL/FL villin-Cre mice exhibit uninflamed intestines without polyps, A20(FL/FL villin-Cre APC(min/+ mice contain far greater numbers and larger colonic polyps than control APC(min mice. We find that A20 binds to the β-catenin destruction complex and restricts canonical wnt signaling by supporting ubiquitination and degradation of β-catenin in intestinal epithelial cells. Moreover, acute deletion of A20 from intestinal epithelial cells in vivo leads to enhanced expression of the β-catenin dependent genes cyclinD1 and c-myc, known promoters of colon cancer. Taken together, these findings demonstrate new roles for A20 in restricting β-catenin signaling and preventing colon tumorigenesis.

  17. Possible contribution of rubiadin, a metabolite of madder color, to renal carcinogenesis in rats.

    Science.gov (United States)

    Inoue, Kaoru; Yoshida, Midori; Takahashi, Miwa; Fujimoto, Hitoshi; Ohnishi, Kuniyoshi; Nakashima, Koichi; Shibutani, Makoto; Hirose, Masao; Nishikawa, Akiyoshi

    2009-04-01

    Madder color (MC) has been shown to exert carcinogenic potential in the rat kidney in association with degeneration, karyomegaly, increased cell proliferation of renal tubule cells and increased renal 8-OHdG levels. To clarify the causal relationship of components and metabolites of MC to renal carcinogenesis, male F344 rats were fed lucidin-3-O-primeveroside (LuP) or alizarin (Alz), and the genotoxic LuP metabolites lucidin (Luc) or rubiadin (Rub) for up to 26 weeks. After one week and four weeks, Luc did not induce any renal changes. In contrast, after one week, cortical tubule degeneration was apparent in the Alz and LuP groups, and cytoplasmic swelling with basophilic change and karyomegaly in the outer medulla was observed only in the Rub group. LuP and Rub increased the proliferative activity of tubule cells in the outer medulla, and Alz and LuP increased renal 8-OHdG levels. After 26 weeks, Rub but not Alz induced atypical tubules, a putative preneoplastic lesion, and karyomegaly in the outer medulla. These results indicate that Rub may be a potent carcinogenic metabolite of MC, targeting proximal tubule cells in the outer medulla, although oxidative stress increased by Alz or LuP might also be involved in renal carcinogenesis by MC.

  18. Implication of human telomerase reverse transcriptase in cervical carcinogenesis and cancer recurrence.

    Science.gov (United States)

    Wang, P-H; Ko, J-L

    2006-01-01

    The objective of this study was to evaluate the implication of human telomerase reverse transcriptase (hTERT) in cervical carcinogenesis and cancer recurrence. One hundred three cases of uterine cervix, including 20 normal, 13 low-grade squamous intraepithelial lesion (LSIL), 30 high-grade squamous intraepithelial lesion (HSIL), and 40 squamous cell carcinoma (SCC) tissues, were evaluated for hTERT immunoreactivity. The expressions of hTERT in normal, LSIL, HSIL, and SCC tissues were compared by Fisher exact or Chi-square test. The relationships between hTERT and clinicopathologic variables of SCC were also assessed. Furthermore, SCC patients were subdivided into negative and positive hTERT expression subgroups, and Kaplan-Meier curves were used to plot the cumulative recurrence hazard for 5 years. There was a significant difference for hTERT expression between LSIL and HSIL subgroups (P recurrence hazard for 5 years was about 29% in positive hTERT expression subgroup compared to 0% in negative hTERT subgroup (P = 0.2866). In conclusion, a point stage of HSIL exists in the progression of cervical carcinogenesis when the hTERT expression increases significantly. Moreover, SCC patients with positive hTERT expression may have higher cumulative recurrence hazard.

  19. St. John's Wort Attenuates Colorectal Carcinogenesis in Mice through Suppression of Inflammatory Signaling.

    Science.gov (United States)

    Manna, Soumen K; Golla, Srujana; Golla, Jaya Prakash; Tanaka, Naoki; Cai, Yan; Takahashi, Shogo; Krausz, Kristopher W; Matsubara, Tsutomu; Korboukh, Ilia; Gonzalez, Frank J

    2015-09-01

    Despite widespread use as well as epidemiologic indications, there have been no investigations into the effect of St. John's wort (SJW) extract on colorectal carcinogenesis in vivo. This study reports a systematic evaluation of the impact of dietary supplementation of SJW extract on azoxymethane-induced colorectal carcinogenesis in mice. Mice were fed with either AIN-93G (control) diet or SJW extract-supplemented diet (SJW diet) prior to azoxymethane treatment. SJW diet was found to significantly improve the overall survival of azoxymethane-treated mice. Pretreatment with the SJW diet significantly reduced body weight loss as well as decrease of serum albumin and cholesterol levels associated with azoxymethane-induced colorectal tumorigenesis. SJW diet-fed mice showed a significant decrease in tumor multiplicity along with a decrease in incidence of large tumors and a trend toward decreased total tumor volume in a dose-dependent manner. A short-term study, which examined the effect of SJW prior to rectal bleeding, also showed decrease in colorectal polyps in SJW diet-fed mice. Nuclear factor kappa B (NF-κB) and extracellular signal-regulated kinase (ERK1/2) pathways were attenuated by SJW administration. SJW extract resulted in early and continuous attenuation of these pathways in the colon epithelium of SJW diet-fed mice under both short-term and long-term treatment regimens. In conclusion, this study demonstrated the chemopreventive potential of SJW extract against colorectal cancer through attenuation of proinflammatory processes.

  20. In Vivo Antineoplastic Effects of the NSAID Sulindac in an Oral Carcinogenesis Model.

    Science.gov (United States)

    Katoumas, Konstantinos; Nikitakis, Nikolaos; Perrea, Despina; Dontas, Ismene; Sklavounou, Alexandra

    2015-07-01

    The antineoplastic properties of the NSAID sulindac have long been studied. The purpose of this study was to explore sulindac's in vivo effects on oral squamous cell carcinoma (SCC) oncogenesis using the hamster cheek pouch oral carcinogenesis model (HOCM). Thirty Syrian golden hamsters were divided into three experimental and two control groups (n = 6 each). The animals' right buccal pouches were treated with carcinogen for 9 weeks in one experimental and one control group and for 14 weeks in all other three groups. The animals of two experimental groups received sulindac from the 1st week and those of the third experimental group from the 10th week. After the end of carcinogenesis, treated buccal pouches were removed and examined. In animals treated with carcinogen for 14 weeks, development of oral SCC and tumor volume were significantly lower in animals that received sulindac from the first week of the experiment. Oral SCC developing in animals that received sulindac were more frequently well differentiated compared with the control group. In animals treated with carcinogen for 9 weeks, the animals that received sulindac developed lower grade of epithelial dysplasia. Proliferation index Ki-67 and positivity for the antiapoptotic molecule survivin were lower in the animals that received sulindac. Treatment with sulindac appears to delays the progression of oral premalignant lesions to oral SCC in the HOCM, also resulting in smaller and better differentiated tumors. These in vivo antineoplastic effects may be related to sulindac's ability to decrease cell proliferation and to prevent survivin expression.

  1. Inhibition of N-nitrosodiethylamine carcinogenesis in mice by naturally occurring organosulfur compounds and monoterpenes.

    Science.gov (United States)

    Wattenberg, L W; Sparnins, V L; Barany, G

    1989-05-15

    Naturally occurring compounds belonging to two chemical groups were studied for their capacities to inhibit N-nitrosodiethylamine (NDEA)-induced carcinogenesis in female A/J mice. One group consists of organosulfur compounds found in Allium species, including garlic, onions, leeks, and shallots, and the other, two monoterpenes, i.e., D-limonene and D-carvone. In an initial experiment, in which organosulfur compounds were investigated, diallyl disulfide, allyl mercaptan, and allyl methyl disulfide were found to produce a marked inhibition of NDEA-induced neoplasia of the forestomach when the test compounds were administered p.o. 96 and 48 h prior to NDEA. The most potent was diallyl disulfide which reduced forestomach tumor formation by more than 90%. Pulmonary adenoma formation also was inhibited but to a considerably lesser extent, i.e., about 30%. In three additional experiments, test compounds were given p.o. either 15 min or 1 h prior to NDEA. Under these conditions diallyl disulfide and allyl mercaptan again inhibited forestomach tumor formation substantially, i.e., greater than 75%, and pulmonary adenoma formation marginally, i.e., less than 20%. In these experiments D-limonene and D-carvone were tested and reduced forestomach tumor formation by slightly over 60% and pulmonary adenoma formation by about 35%. The results of these studies provide evidence of an increasing diversity of naturally occurring compounds having the capacity to inhibit nitrosamine carcinogenesis.

  2. Possible mechanisms by which pro- and prebiotics influence colon carcinogenesis and tumor growth.

    Science.gov (United States)

    Reddy, B S

    1999-07-01

    Oligofructose and inulin, selective fermentable chicory fructans, have been shown to stimulate the growth of bifidobacteria, which are regarded as beneficial strains in the colon. Studies were designed to evaluate inulin (Raftiline) and oligofructose (Raftilose) for their potential inhibitory properties against the development of colonic aberrant crypt foci (ACF) in rats. ACF are putative preneoplastic lesions from which adenomas and carcinomas may develop in the colon. The results of this study indicate that dietary administration of oligofructose and inulin inhibits the development of ACF in the colon, suggesting the potential colon tumor inhibitory properties of chicory fructans. The degree of ACF inhibition was more pronounced in animals given inulin than in those fed oligofructose. Because these prebiotics selectively stimulate the growth of bifidobacteria, ornithine decarboxylase (ODC) activities, ras-p21 ontoprotein expressions and tumor inhibitory activity of lyophilized cultures of Bifidobacterium longum against chemically induced colon and mammary carcinogenesis and against colonic tumor cell proliferation were examined. Dietary administration of lyophilized cultures of B. longum strongly suppressed colon and mammary tumor development and tumor burden. Inhibition of colon carcinogenesis was associated with a decrease in colonic mucosal cell proliferation and activities of colonic mucosal and tumor ornithine decarboxylase and ras-p21. Human clinical trials are likely to broaden our insight into the importance of the pre- and probiotics in health and disease.

  3. Latest insights into the effects of Helicobacter pylori infection on gastric carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    Kazunari Murakami; Masaaki Kodama; Toshio Fujioka

    2006-01-01

    There appears to be the strong association between Helicobacter pylori (H pylori) and gastric cancer. We reviewed the latest evidences about the effects of H pylori infection on gastric carcinogenesis, classified into epidemiology, dynamics of gastric mucosal changes,DNA damages, virulence factors, host factors, and source of gastric malignancy. Through the considerable progress made in research into virulence factors resulting from differences between H pylori strains, such as cagA positivity, as well as into host factors, such as gene polymorphisms, a diverse spectrum of H pyloriassociated diseases, including gastric cancer, is beginning to lend itself to elucidation. The impact of the novel hypothesis advanced by Houghton et al proposing bonemarrow derived stem cells (BMDC) as a potential source of gastric malignancy on evolving research remains to be seen with interest. Further progress in research into H pylori eradication as a viable prophylaxis of gastric cancer, as well as into the mechanisms of gastric carcinogenesis, is to be eagerly awaited for the current year and beyond.

  4. A preliminary operational classification system for nonmutagenic modes of action for carcinogenesis.

    Science.gov (United States)

    Hattis, D; Chu, M; Rahmioglu, N; Goble, R; Verma, P; Hartman, K; Kozlak, M

    2009-01-01

    This article proposes a system of categories for nonmutagenic modes of action for carcinogenesis. The classification is of modes of action rather than individual carcinogens, because the same compound can affect carcinogenesis in more than one way. Basically, we categorize modes of action as: (1) co-initiation (facilitating the original mutagenic changes in stem and progenitor cells that start the cancer process) (e.g. induction of activating enzymes for other carcinogens); (2) promotion (enhancing the relative growth vs differentiation/death of initiated clones (e.g. inhibition of growth-suppressing cell-cell communication); (3) progression (enhancing the growth, malignancy, or spread of already developed tumors) (e.g. suppression of immune surveillance, hormonally mediated growth stimulation for tumors with appropriate receptors by estrogens); and (4) multiphase (e.g., "epigenetic" silencing of tumor suppressor genes). A priori, agents that act at relatively early stages in the process are expected to manifest greater relative susceptibility in early life, whereas agents that act via later stage modes will tend to show greater susceptibility for exposures later in life.

  5. Experimental Animal Models of Pancreatic Carcinogenesis for Prevention Studies and Their Relevance to Human Disease

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Mami, E-mail: mtakahas@ncc.go.jp; Hori, Mika; Mutoh, Michihiro [Division of Cancer Development System, Carcinogenesis Research Group, National Cancer Center Research Institute, 1-1, Tsukiji 5-chome, Chuo-ku, Tokyo 104-0045 (Japan); Wakabayashi, Keiji [Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, Yada 52-1, Suruga-ku, Shizuoka 422-8526 (Japan); Nakagama, Hitoshi [Division of Cancer Development System, Carcinogenesis Research Group, National Cancer Center Research Institute, 1-1, Tsukiji 5-chome, Chuo-ku, Tokyo 104-0045 (Japan)

    2011-02-09

    Pancreatic cancer is difficult to cure, so its prevention is very important. For this purpose, animal model studies are necessary to develop effective methods. Injection of N-nitrosobis(2-oxopropyl)amine (BOP) into Syrian golden hamsters is known to induce pancreatic ductal adenocarcinomas, the histology of which is similar to human tumors. Moreover, K-ras activation by point mutations and p16 inactivation by aberrant methylation of 5′ CpG islands or by homozygous deletions have been frequently observed in common in both the hamster and humans. Thus, this chemical carcinogenesis model has an advantage of histopathological and genetic similarity to human pancreatic cancer, and it is useful to study promotive and suppressive factors. Syrian golden hamsters are in a hyperlipidemic state even under normal dietary conditions, and a ligand of peroxizome proliferator-activated receptor gamma was found to improve the hyperlipidemia and suppress pancreatic carcinogenesis. Chronic inflammation is a known important risk factor, and selective inhibitors of inducible nitric oxide synthase and cyclooxygenase-2 also have protective effects against pancreatic cancer development. Anti-inflammatory and anti-hyperlipidemic agents can thus be considered candidate chemopreventive agents deserving more attention.

  6. Luteolin supplementation adjacent to aspirin treatment reduced dimethylhydrazine-induced experimental colon carcinogenesis in rats.

    Science.gov (United States)

    Osman, Neamt H A; Said, Usama Z; El-Waseef, Ahmed M; Ahmed, Esraa S A

    2015-02-01

    Previous studies have shown that aspirin is used in colon cancer treatment. However, long-term of Aspirin usage is limited to gastric and renal toxicity. Luteolin (LUT) has cancer prevention and anti-inflammatory effects. The present study was designed to investigate the effect of LUT supplementation and Aspirin treatment in dimethylhydrazine (DMH)-induced carcinogenesis in rats. DMH (20 mg/kg BW/week) treated rats received gavages with Aspirin (50 mg/kg BW/week) and LUT (0.2 mg/kg BW/day) for 15 weeks. DMH injections induce colon polyps and renal bleeding, significantly increasing carcinoembryonic antigen (CEA), cyclooxygenase-2 (COX-2), oxidative stress, and kidney function tests and reducing antioxidant markers. Either Aspirin or LUT gavages alone or combined produce a significant decrease in colon polyp number and size, significantly decreasing CEA, COX-2, and oxidative stress and increasing antioxidant markers. In conclusion, the supplementations of LUT adjacent to Aspirin in the treatment of DMH-induced carcinogenesis in rats reflect a better effect than the use of Aspirin alone.

  7. Experimental Animal Models of Pancreatic Carcinogenesis for Prevention Studies and Their Relevance to Human Disease

    Directory of Open Access Journals (Sweden)

    Hitoshi Nakagama

    2011-02-01

    Full Text Available Pancreatic cancer is difficult to cure, so its prevention is very important. For this purpose, animal model studies are necessary to develop effective methods. Injection of N-nitrosobis(2-oxopropylamine (BOP into Syrian golden hamsters is known to induce pancreatic ductal adenocarcinomas, the histology of which is similar to human tumors. Moreover, K-ras activation by point mutations and p16 inactivation by aberrant methylation of 5’ CpG islands or by homozygous deletions have been frequently observed in common in both the hamster and humans. Thus, this chemical carcinogenesis model has an advantage of histopathological and genetic similarity to human pancreatic cancer, and it is useful to study promotive and suppressive factors. Syrian golden hamsters are in a hyperlipidemic state even under normal dietary conditions, and a ligand of peroxizome proliferator-activated receptor gamma was found to improve the hyperlipidemia and suppress pancreatic carcinogenesis. Chronic inflammation is a known important risk factor, and selective inhibitors of inducible nitric oxide synthase and cyclooxygenase-2 also have protective effects against pancreatic cancer development. Anti-inflammatory and anti-hyperlipidemic agents can thus be considered candidate chemopreventive agents deserving more attention.

  8. Helicobacter pylori-infected animal models are extremely suitable for the investigation of gastric carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    Masaaki Kodama; Kazunari Murakami; Ryugo Sato; Tadayoshi Okimoto; Akira Nishizono; Toshio Fujioka

    2005-01-01

    Although various animal models have been developed to clarify gastric carcinogenesis, apparent mechanism of gastric cancer was not clarified in recent years. Since the recognition of the pathogenicity of Helicobacter pylori (Hpylori), several animal models with Hpylori infection have been developed to confirm the association between Hpylori and gastric cancer. Nonhuman primate and rodent models were suitable for this study. Japanese monkey model revealed atrophic gastritis and p53mutation after long-term infection of Hpylori. Mongolian gerbil model showed the development of gastric carcinoma with H pylori infection alone, as well as with combination of chemical carcinogens, such as N-methylN-nitrosourea and N-methyl-N-nitro-N'-nitrosoguanidine.The histopathological changes of these animal models after Hpylori inoculation are closely similar to those in human beings with Hpylori infection. Eradication therapy attenuated the development of gastric cancer in Hpyloriinfected Mongolian gerbil. Although several features of animal models differ from those seen in human beings,these experimental models provide a starting point for further studies to clarify the mechanism of gastric carcinogenesis as a result of Hpylori infection and assist the planning of eradication therapy to prevent gastric carcinoma.

  9. Nutraceutical Approach for Preventing Obesity-Related Colorectal and Liver Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Hisataka Moriwaki

    2012-01-01

    Full Text Available Obesity and its related metabolic abnormalities, including insulin resistance, alterations in the insulin-like growth factor-1 (IGF-1/IGF-1 receptor (IGF-1R axis, and the state of chronic inflammation, increase the risk of colorectal cancer (CRC and hepatocellular carcinoma (HCC. However, these findings also indicate that the metabolic disorders caused by obesity might be effective targets to prevent the development of CRC and HCC in obese individuals. Green tea catechins (GTCs possess anticancer and chemopreventive properties against cancer in various organs, including the colorectum and liver. GTCs have also been known to exert anti-obesity, antidiabetic, and anti-inflammatory effects, indicating that GTCs might be useful for the prevention of obesity-associated colorectal and liver carcinogenesis. Further, branched-chain amino acids (BCAA, which improve protein malnutrition and prevent progressive hepatic failure in patients with chronic liver diseases, might be also effective for the suppression of obesity-related carcinogenesis because oral supplementation with BCAA reduces the risk of HCC in obese cirrhotic patients. BCAA shows these beneficial effects because they can improve insulin resistance. Here, we review the detailed relationship between metabolic abnormalities and the development of CRC and HCC. We also review evidence, especially that based on our basic and clinical research using GTCs and BCAA, which indicates that targeting metabolic abnormalities by either pharmaceutical or nutritional intervention may be an effective strategy to prevent the development of CRC and HCC in obese individuals.

  10. CtBP1 associates metabolic syndrome and breast carcinogenesis targeting multiple miRNAs

    Science.gov (United States)

    De Luca, Paola; Dalton, Guillermo N.; Scalise, Georgina D.; Moiola, Cristian P.; Porretti, Juliana; Massillo, Cintia; Kordon, Edith; Gardner, Kevin; Zalazar, Florencia; Flumian, Carolina; Todaro, Laura; Vazquez, Elba S.; Meiss, Roberto; De Siervi, Adriana

    2016-01-01

    Metabolic syndrome (MeS) has been identified as a risk factor for breast cancer. C-terminal binding protein 1 (CtBP1) is a co-repressor of tumor suppressor genes that is activated by low NAD+/NADH ratio. High fat diet (HFD) increases intracellular NADH. We investigated the effect of CtBP1 hyperactivation by HFD intake on mouse breast carcinogenesis. We generated a MeS-like disease in female mice by chronically feeding animals with HFD. MeS increased postnatal mammary gland development and generated prominent duct patterns with markedly increased CtBP1 and Cyclin D1 expression. CtBP1 induced breast cancer cells proliferation. Serum from animals with MeS enriched the stem-like/progenitor cell population from breast cancer cells. CtBP1 increased breast tumor growth in MeS mice modulating multiple genes and miRNA expression implicated in cell proliferation, progenitor cells phenotype, epithelial to mesenchymal transition, mammary development and cell communication in the xenografts. These results define a novel function for CtBP1 in breast carcinogenesis. PMID:26933806

  11. Andrographolide inhibits oral squamous cell carcinogenesis through NF-κB inactivation.

    Science.gov (United States)

    Wang, L-J; Zhou, X; Wang, W; Tang, F; Qi, C-L; Yang, X; Wu, S; Lin, Y-Q; Wang, J-T; Geng, J-G

    2011-10-01

    The NF-κB family of transcription factors is essential for promoting cell proliferation and preventing cell apoptosis. We have previously shown that Andrographolide (Andro) isolated from an herbal plant, Andrographis paniculata, covalently modifies reduced cysteine(62) in the oligonucleotide binding pocket of p50 for inhibition of NF-κB activation. Here we report that Andro, but not its inactive structural analog 4H-Andro, potently suppressed squamous cell carcinogenesis induced by 7,12-dimethyl-1,2-benzanthracene (DMBA) in the hamster model of cheek buccal pouch. Compared with 4H-Andro, Andro reduced phosphorylation of p65 (Ser536) and IκBα (Ser32/36) for inhibiting aberrant NF-κB activation, suppressed c-Myc and cyclin D1 expression and attenuated neoplastic cell proliferation, promoted cancerous cell apoptosis, and mitigated tumor-induced angiogenesis. Consistently, Andro retarded growth, decreased proliferation, and promoted apoptosis of Tb cells, a human tongue squamous cell carcinoma cell line, in time- and dose-dependent manners, with concomitant reduction of the expression of NF-κB targeting molecules in vitro. Our results thus demonstrate that NF-κB activation plays important roles in the pathogenesis of chemically induced squamous cell carcinoma. By inhibition of aberrant NF-κB activation, Andro treats chemically induced oral squamous cell carcinogenesis.

  12. Epigenetic regulation of DNA repair machinery in Helicobacter pylori-induced gastric carcinogenesis.

    Science.gov (United States)

    Santos, Juliana Carvalho; Ribeiro, Marcelo Lima

    2015-08-14

    Although thousands of DNA damaging events occur in each cell every day, efficient DNA repair pathways have evolved to counteract them. The DNA repair machinery plays a key role in maintaining genomic stability by avoiding the maintenance of mutations. The DNA repair enzymes continuously monitor the chromosomes to correct any damage that is caused by exogenous and endogenous mutagens. If DNA damage in proliferating cells is not repaired because of an inadequate expression of DNA repair genes, it might increase the risk of cancer. In addition to mutations, which can be either inherited or somatically acquired, epigenetic silencing of DNA repair genes has been associated with carcinogenesis. Gastric cancer represents the second highest cause of cancer mortality worldwide. The disease develops from the accumulation of several genetic and epigenetic changes during the lifetime. Among the risk factors, Helicobacter pylori (H. pylori) infection is considered the main driving factor to gastric cancer development. Thus, in this review, we summarize the current knowledge of the role of H. pylori infection on the epigenetic regulation of DNA repair machinery in gastric carcinogenesis.

  13. Study of the mechanism of carcinogenesis by carcinogens which are negative in the Ames test. Progress report, April 1-September 1, 1979

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-01-01

    Carcinogens ethionine, thioacetamide, and actinomycin D, all of which are negative in the Ames test and all of which raise the progesterone level in the chicken, were tested to determine their physiological role in carcinogenesis. The optimization of the carcinogenesis model also included evaluation of the chicken as the biological indicator of physiological changes relative to the above compounds. (PCS)

  14. The molecular biology of cancer.

    Science.gov (United States)

    Bertram, J S

    2000-12-01

    identifies key genes directly involved in carcinogenesis and demonstrates how mutations in these genes allow cells to circumvent cellular controls. This detailed understanding of the process of carcinogenesis at the molecular level has only been possible because of the advent of modern molecular biology. This new discipline, by precisely identifying the molecular basis of the differences between normal and malignant cells, has created novel opportunities and provided the means to specifically target these modified genes. Whenever possible this review highlights these opportunities and the attempts being made to generate novel, molecular based therapies against cancer. Successful use of these new therapies will rely upon a detailed knowledge of the genetic defects in individual tumors. The review concludes with a discussion of how the use of high throughput molecular arrays will allow the molecular pathologist/therapist to identify these defects and direct specific therapies to specific mutations.

  15. Serrated polyposis syndrome: Molecular, pathological and clinical aspects

    Institute of Scientific and Technical Information of China (English)

    Carla Guarinos; Cristina Sánchez-Fortún; María Rodríguez-Soler; Cristina Alenda; Artemio Payá; Rodrigo Jover

    2012-01-01

    Hyperplastic polyps have traditionally been considered not to have malignant potential.New pathological classification of serrated polyps and recent discoveries about the serrated pathway of carcinogenesis have revolutionized the concepts and revitalized the research in this area.Until recently,it has been thought that most colorectal cancers arise from conventional adenomas via the traditional tumor suppressor pathway initiated by a mutation of the APC gene,but it has been found that this pathway accounts for only approximately 70%-80%of colorectal cancer (CRC) cases.The majority of the remaining colorectal cancer cases follow an alternative pathway leading to CpG island methylator phenotype carcinoma with BRAF mutation and with or without microsatellite instability.The mechanism of carcinomas arising from this alternative pathway seems to begin with an activating mutation of the BRAF oncogene.Serrated polyposis syndrome is a relatively rare condition characterized by multiple and/or large serrated polyps of the colon.Clinical characteristics,etiology and relationship of serrated polyposis syndrome to CRC have not been clarified yet.Patients with this syndrome show a high risk of CRC and both sporadic and hereditary cases have been described.Clinical criteria have been used for diagnosis and frequent colonoscopy surveillance should be performed in order to prevent colorectal cancer.In this review,we try to gather new insights into the molecular pathogenesis of serrated polyps in order to understand their possible clinical implications and to make an approach to the management of this syndrome.

  16. The Extended Enterprise concept

    DEFF Research Database (Denmark)

    Larsen, Lars Bjørn; Vesterager, Johan; Gobbi, Chiara

    1999-01-01

    This paper provides an overview of the work that has been done regarding the Extended Enterprise concept in the Common Concept team of Globeman 21 including references to results deliverables concerning the development of the Extended Enterprise concept. The first section presents the basic concept...... picture from Globeman21, which illustrates the Globeman21 way of realising the Extended Enterprise concept. The second section presents the Globeman21 EE concept in a life cycle perspective, which to a large extent is based on the thoughts and ideas behind GERAM (ISO/DIS 15704)....

  17. Nanotechnology Review: Molecular Electronics to Molecular Motors

    Science.gov (United States)

    Srivastava, Deepak; Saini, Subhash (Technical Monitor)

    1998-01-01

    Reviewing the status of current approaches and future projections, as already published in scientific journals and books, the talk will summarize the direction in which computational and experimental nanotechnologies are progressing. Examples of nanotechnological approaches to the concepts of design and simulation of carbon nanotube based molecular electronic and mechanical devices will be presented. The concepts of nanotube based gears and motors will be discussed. The above is a non-technical review talk which covers long term precompetitive basic research in already published material that has been presented before many US scientific meeting audiences.

  18. Helicobacter pylori eradication to prevent gastric cancer:underlying molecular and cellular mechanisms

    Institute of Scientific and Technical Information of China (English)

    Shingo Tsuji; Norio Hayashi; Masahiko Tsujii; Hiroaki Murata; Tsutomu Nishida; Masato Komori; Masakazu Yasumaru; Shuji Ishii; Yoshiaki Sasayama; Sunao Kawano

    2006-01-01

    Numerous cellular and molecular events have been described in development of gastric cancer. In this article,we overviewed roles of Helicobacter pylori(H pylori) infection on some of the important events in gastric carcinogenesis and discussed whether these cellular and molecular events are reversible after cure of the infection. There are several bacterial components affecting gastric epithelial kinetics and promotion of gastric carcinogenesis. The bacterium also increases risks of genetic instability and mutations due to NO and other reactive oxygen species. Epigenetic silencing of tumor suppressor genes such as RUNX3 may alter the frequency of phenotype change of gastric glands to those with intestinal metaplasia. Host factors such as increased expression of growth factors, cytokines and COX-2 have been also reported in non-cancerous tissue in H pylori-positive subjects. It is noteworthy that most of the above phenomena are reversed after the cure of the infection. However,some of them including overexpression of COX-2 continue to exist and may increase risks for carcinogenesis in metaplastic or dysplastic mucosa even after successful H pylori eradication. Thus, H pylori eradication may not completely abolish the risk for gastric carcinogenesis. Efficiency of the cure of the infection in suppressing gastric cancer depends on the timing and the target population,and warrant further investigation.

  19. Age-dependent change in biological characteristics of stem cells in radiation-induced mammary carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Shimada, Yoshiya; Nishimura, Mayumi; Kakinuma, Shizuko; Imaoka, Tatsuhiko [National Institute of Radiological Sciences, Anagawa, Chiba (Japan); Yasukawa-Barnes, Jane; Gould, Michael N.; Clifton, Kelly H. [Univ. of Wisconsin, Department of Human Oncology, Madison, WI (United States)

    2003-07-01

    If you ask what types of cells are the targets for carcinogenesis, a popular answer would be that cancer arises from stem cells. Stem cells are cells that are capable of both self-renewal and generation of differentiated progenies. If the hypothesis of 'cancer as stem cell disease' is correct, the risk of carcinogenesis should be a function of the number of stem cells and their responsiveness of carcinogen-induced damage. In the present study, we addressed the feasibility of this hypothesis using the rat mammary carcinogenesis model. One of the important conclusions emerging from studies on atomic bomb survivors concerns age-related changes in the susceptibility to breast cancer. The relative risk of breast cancer is very high among women exposed to ionizing radiation before or during puberty, and it decreases thereafter. Little information is available, however, on age-related changes in the radiobiological nature of mammary stem cells. We examined age-associated changes in the number of mammary stem-like cells (clonogens) and their susceptibility to radiation in terms of cell death and carcinogenic initiation frequency. The results were as follows. (1) During the prepubertal period, the total number of mammary clonogens per rat increased exponentially with a population doubling time of {approx}4 days. After puberty, the doubling time lengthened to {approx}30 days. The total number of clonogens in abdominal and inguinal mammary glands was {approx}200 in 2-week-old rats, while it was {approx}5600 in 8-week-old rats. (2) The survival curves of clonogenic cells after irradiation indicated that radiation sensitivity of the cells before and during puberty was much higher than after puberty. (3) The initiation frequency of the clonogens from prepubertal rats after 5 Gy irradiation was four times higher than that of the clonogens from post-pubertal rats. These results suggest that changes in the number of stem cells and their radiobiological characteristics

  20. Key concepts in energy

    CERN Document Server

    Madureira, Nuno Luis

    2014-01-01

    Highlights how key energy concepts surfaced, tracing their evolution throughout history to encompasses four economic concepts and four technological-engineering concepts developed through their history to conclude with current economic and environmental sciences Considers the process of energy-substitutions through complementary usages, hybridization and technological mixes Combines a conceptual approach with key theoretical concepts from engineering, geological and economic sciences providing cross disciplinary overview of energy fundamentals in a short and focused reading

  1. Biologia molecular do câncer colorretal: uma revolução silenciosa em andamento Molecular biology of colorectal cancer: a silent revolution

    Directory of Open Access Journals (Sweden)

    Mauro de Souza Leite Pinho

    2008-09-01

    Full Text Available Embora os estudos sobre biologia molecular permaneçam como a principal expectativa para o surgimento de novos conceitos e recursos para o tratamento do câncer colorretal, a ausência de resultados de real impacto do ponto de vista clínico ao longo dos últimos anos podem representar uma frustração para quem não esteja acompanhando de perto a evolução das pesquisas nesta área. Assim sendo, nosso objetivo no presente texto é apresentar uma breve revisão do caminho percorrido até o momento desde os trabalhos pioneiros sobre carcinogênese colorretal até as pesquisas mais recentes sobre proteômica, demonstrando assim o constante fluxo de grandes avanços os quais possibilitam uma previsão realista a curto ou médio prazo da disponibilização de recursos de amplo impacto, com potencial para alterar de forma relevante os resultados do tratamento desta importante doença.Despite remaining as the main hope for emerging new concepts and strategies for treatment of colorectal cancer, the lack of results with clinical impact over the last years may contribute to frustrate those not entirely aware about current research data. So, the aim of this paper is to present a brief review since the first molecular biology studies in colorectal carcinogenesis until recent advances in proteomics, in order to demonstrate the consistent production of new data supporting a realistic expectancy for a near future availability of high impact resources that may change dramatically the results of treatment of colorectal cancer.

  2. Conceptions of Ability.

    Science.gov (United States)

    Jagacinski, Carolyn M.; Nicholls, John G.

    Two different conceptions of ability are proposed. The first conception of ability is more differentiated and generally employed by adults and older children. Here ability level is defined with reference to the performance of others assuming that optimum effort was employed. High ability means higher than others. The second conception of ability…

  3. Concept Image Revisited

    Science.gov (United States)

    Bingolbali, Erhan; Monaghan, John

    2008-01-01

    Concept image and concept definition is an important construct in mathematics education. Its use, however, has been limited to cognitive studies. This article revisits concept image in the context of research on undergraduate students' understanding of the derivative which regards the context of learning as paramount. The literature, mainly on…

  4. Threshold Concepts in Biochemistry

    Science.gov (United States)

    Loertscher, Jennifer

    2011-01-01

    Threshold concepts can be identified for any discipline and provide a framework for linking student learning to curricular design. Threshold concepts represent a transformed understanding of a discipline, without which the learner cannot progress and are therefore pivotal in learning in a discipline. Although threshold concepts have been…

  5. Lupeol, a bioactive triterpene, prevents tumor formation during 7,12-dimethylbenz(a)anthracene induced oral carcinogenesis.

    Science.gov (United States)

    Palanimuthu, D; Baskaran, N; Silvan, S; Rajasekaran, D; Manoharan, S

    2012-10-01

    The oral cancer chemopreventive efficacy of lupeol, a bioactive triterpene, was assessed by monitoring the tumor incidence and using the status of phase I and II xenobiotic metabolizing enzymes, lipid peroxidation and antioxidants as biochemical end points during 7,12-dimethylbenz(a)anthracene (DMBA) induced hamster buccal pouch carcinogenesis. Oral tumors were developed in the buccal pouch of golden Syrian hamsters by painting with 0.5 % DMBA three times a week for 14 weeks. Well differentiated oral squamous cell carcinoma with marked abnormalities in the status of biochemical markers were noticed in hamsters treated with DMBA alone. Oral administration of lupeol at a dose of 50 mg/kg bw completely inhibited the formation of oral tumors and restored the status of biochemical markers during DMBA induced oral carcinogenesis. The present study thus demonstrates the chemopreventive potential of lupeol in DMBA induced oral carcinogenesis. The chemopreventive potential of lupeol is probably due to its antioxidant or free radical scavenging property and modulating effect on phase I and II xenobiotic metabolizing enzymes in favour of the excretion of carcinogenic metabolites during DMBA induced hamster buccal pouch carcinogenesis.

  6. Effects of long term feeding of raw soya bean flour on virus- induced pancreatic carcinogenesis in guinea fowl

    NARCIS (Netherlands)

    Kirev, T.; Woutersen, R.A.; Kiril, A.

    1999-01-01

    The effects of a diet enriched with 25% raw soya bean flour (RSF) on the pancreas and on the avian retrovirus Pts 56-induced pancreatic carcinogenesis in guinea fowl were studied. It has been shown that prolonged RSF feeding of new-hatched virus-infected and uninfected guinea fowl-poults induced enl

  7. Epstein-Barr virus in gastric carcinomas and gastric stump carcinomas: a late event in gastric carcinogenesis.

    NARCIS (Netherlands)

    Hausen, A zur; Rees, van B.P.; Beek, van J.; Craanen, M.E.; Bloemena, E.; Offerhaus, GJ; Meijer, C.J.L.M.; Brule, van den AJ

    2004-01-01

    BACKGROUND: To determine at what stage during gastric carcinogenesis Epstein-Barr virus (EBV) enters the gastric epithelial cells, the presence of EBV was investigated in two pathogenetically related but distinct forms of adenocarcinoma of the stomach-gastric carcinoma of the intact stomach (GCIS) a

  8. Theoretical Molecular Biophysics

    CERN Document Server

    Scherer, Philipp

    2010-01-01

    "Theoretical Molecular Biophysics" is an advanced study book for students, shortly before or after completing undergraduate studies, in physics, chemistry or biology. It provides the tools for an understanding of elementary processes in biology, such as photosynthesis on a molecular level. A basic knowledge in mechanics, electrostatics, quantum theory and statistical physics is desirable. The reader will be exposed to basic concepts in modern biophysics such as entropic forces, phase separation, potentials of mean force, proton and electron transfer, heterogeneous reactions coherent and incoherent energy transfer as well as molecular motors. Basic concepts such as phase transitions of biopolymers, electrostatics, protonation equilibria, ion transport, radiationless transitions as well as energy- and electron transfer are discussed within the frame of simple models.

  9. Synergistic effect of radiation on colon carcinogenesis induced by methylazoxymethanol acetate in ACI/N rats

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Takuji; Morishita, Yukio; Kawamori, Toshihiko; Suzui, Masumi; Kojima, Toshihiro; Sugie, Shigeyuki; Mori, Hideki (Gifu Univ. (Japan). Faculty of Medicine)

    1993-10-01

    The effect on colon and liver carcinogenicity in rats of a single X-irradiation exposure given either before or after methylazoxymethanol (MAM) acetate was studied in ACI/N rats of both sexes. A single dose of X-irradiation (3 Gy) was administered either 3 months before or after three weekly s.c. injection of MAM acetate (25 mg/kg body weight). At 365 days after the start, the incidence and multiplicity of MAM acetate-induced intestinal tumors were enhanced by X-irradiation either prior to or after the MAM acetate treatment. In addition, X-irradiation before MAM acetate increased the incidence of hepatocellular foci in either sex. In females, X-irradiation either before or after MAM acetate exposure decreased intestinal tumorigenesis. These findings suggest an apparent synergism of these agents in intestinal carcinogenesis of male rats. (author).

  10. Acquisition of Genetic Aberrations by Activation-Induced Cytidine Deaminase (AID) during Inflammation-Associated Carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Takai, Atsushi; Marusawa, Hiroyuki, E-mail: maru@kuhp.kyoto-u.ac.jp; Chiba, Tsutomu [Department of Gastroenterology and Hepatology, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto 606-8507 (Japan)

    2011-06-22

    Genetic abnormalities such as nucleotide alterations and chromosomal disorders that accumulate in various tumor-related genes have an important role in cancer development. The precise mechanism of the acquisition of genetic aberrations, however, remains unclear. Activation-induced cytidine deaminase (AID), a nucleotide editing enzyme, is essential for the diversification of antibody production. AID is expressed only in activated B lymphocytes under physiologic conditions and induces somatic hypermutation and class switch recombination in immunoglobulin genes. Inflammation leads to aberrant AID expression in various gastrointestinal organs and increased AID expression contributes to cancer development by inducing genetic alterations in epithelial cells. Studies of how AID induces genetic disorders are expected to elucidate the mechanism of inflammation-associated carcinogenesis.

  11. Acquisition of Genetic Aberrations by Activation-Induced Cytidine Deaminase (AID during Inflammation-Associated Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Tsutomu Chiba

    2011-06-01

    Full Text Available Genetic abnormalities such as nucleotide alterations and chromosomal disorders that accumulate in various tumor-related genes have an important role in cancer development. The precise mechanism of the acquisition of genetic aberrations, however, remains unclear. Activation-induced cytidine deaminase (AID, a nucleotide editing enzyme, is essential for the diversification of antibody production. AID is expressed only in activated B lymphocytes under physiologic conditions and induces somatic hypermutation and class switch recombination in immunoglobulin genes. Inflammation leads to aberrant AID expression in various gastrointestinal organs and increased AID expression contributes to cancer development by inducing genetic alterations in epithelial cells. Studies of how AID induces genetic disorders are expected to elucidate the mechanism of inflammation-associated carcinogenesis.

  12. Potential role of septins in oral carcinogenesis: An update and avenues for future research

    Directory of Open Access Journals (Sweden)

    Rooban Thavarajah

    2012-01-01

    Full Text Available Septins belong to the GTPase superclass of conserved proteins and have been identified to play a role in diverse aspects of cell biology, from cytokinesis to the maintenance of cellular morphology. At least 14 septins have been identified in humans. With their complex patterns in gene expressions and interaction, it has been reported that alterations in septin expression are observed in human diseases. Although much is not known about the role of human septins in oral carcinogenesis, circumstantial evidence does indicate that it may play a major role. This review intends to summarize the basis of septin biology, with the focus being on the evidence for septin involvement in human oral cancer.

  13. Chronic inflammation-related DNA damage response: a driving force of gastric cardia carcinogenesis.

    Science.gov (United States)

    Lin, Runhua; Xiao, Dejun; Guo, Yi; Tian, Dongping; Yun, Hailong; Chen, Donglin; Su, Min

    2015-02-20

    Gastric cardia cancer (GCC) is a highly aggressive disease associated with chronic inflammation. To investigate the relationship between DNA damage response (DDR) and chronic inflammation, we collected 100 non-tumor gastric cardia specimens of Chaoshan littoral, a high-risk region for esophageal and gastric cardia cancer. A significantly higher proportion of severe chronic inflammation was found in dysplastic epithelia (80.9%) in comparison with that in non-dysplastic tissues (40.7%) (Pchronic inflammation degrees from normal to severe inflammation (Pchronic inflammation-related DNA damage response may be a driving force of gastric cardia carcinogenesis. Based on these findings, DNA damage response in non-malignant tissues may become a promising biomedical marker for predicting malignant transformation in the gastric cardia.

  14. Caryocar brasiliense camb protects against genomic and oxidative damage in urethane-induced lung carcinogenesis

    Directory of Open Access Journals (Sweden)

    N.B.R. Colombo

    2015-01-01

    Full Text Available The antioxidant effects of Caryocar brasiliense Camb, commonly known as the pequi fruit, have not been evaluated to determine their protective effects against oxidative damage in lung carcinogenesis. In the present study, we evaluated the role of pequi fruit against urethane-induced DNA damage and oxidative stress in forty 8-12 week old male BALB/C mice. An in vivo comet assay was performed to assess DNA damage in lung tissues and changes in lipid peroxidation and redox cycle antioxidants were monitored for oxidative stress. Prior supplementation with pequi oil or its extract (15 µL, 60 days significantly reduced urethane-induced oxidative stress. A protective effect against DNA damage was associated with the modulation of lipid peroxidation and low protein and gene expression of nitric oxide synthase. These findings suggest that the intake of pequi fruit might protect against in vivo genotoxicity and oxidative stress.

  15. Suppressive effects of dietary genistin and daidzin on rat prostate carcinogenesis.

    Science.gov (United States)

    Kato, K; Takahashi, S; Cui, L; Toda, T; Suzuki, S; Futakuchi, M; Sugiura, S; Shirai, T

    2000-08-01

    High intake of phytoestrogens through soybeans and their products is thought to be associated with low incidences of prostate and / or breast cancer in Asian countries. Possible chemopreventive effects of genistin or daidzin on rat prostate carcinogenesis were therefore investigated. Male F344 rats were given 10 biweekly subcutaneous injections of 3,2'-dimethyl-4-aminobiphenyl (DMAB) and then either genistin or daidzin in the diet at a concentration of 0.1% for 40 weeks. Other groups of rats given DMAB were treated with genistin or daidzin together with a high dose of testosterone propionate (TP). Both genistin and daidzin reduced the numbers of ventral prostate carcinomas (P daidzin possess anti-cancer effects at relatively early stages of prostate cancer development, providing experimental support for epidemiological findings.

  16. γ-glutamyl tranferase in a model of carcinogenesis in rats

    Directory of Open Access Journals (Sweden)

    S. O. Babij

    2010-07-01

    compounds of rhenium (III with organic ligands and cisplatin (rhenium-platinum system was studied. The increased activity of the membrane bound enzyme and decrease of its cytosolic activity in the red blood cells during development of Guerin’s carcinoma T8 was found. Also the positive impact of the rheniumplatinum system on the enzymatic activity in the erythrocytes was shown, namely: the reduction of membrane bound and increase of cytosolic activity. As a result, the ratio between activity of the membrane bound enzyme and cytosolic one verged towards the correct level. The conclusion was made that the use of membrane bound and soluble γ-glutamyl transferase in the erythrocytes as a diagnostic enzyme of carcinogenesis is reasonable.

  17. The Expression of miR-375 Is Associated with Carcinogenesis in Three Subtypes of Lung Cancer.

    Directory of Open Access Journals (Sweden)

    Yi Jin

    Full Text Available Many studies demonstrated unique microRNA profiles in lung cancer. Nonetheless, the role and related signal pathways of miR-375 in lung cancer are largely unknown. Our study investigated relationships between carcinogenesis and miR-375 in adenocarcinoma, squamous cell carcinoma and small cell lung carcinoma to identify new molecular targets for treatment. We evaluated 723 microRNAs in microdissected cancerous cells and adjacent normal cells from 126 snap-frozen lung specimens using microarrays. We validated the expression profiles of miR-375 and its 22 putative target mRNAs in an independent cohort of 78 snap-frozen lung cancer tissues using quantitative reverse-transcriptase PCR. Moreover, we performed dual luciferase reporter assay and Western blot on 6 targeted genes (FZD8, ITGA10, ITPKB, LRP5, PIAS1 andRUNX1 in small cell lung carcinoma cell line NCI-H82. We also detected the effect of miR-375 on cell proliferation in NCI-H82. We found that miR-375 expression was significantly up-regulated in adenocarcinoma and small cell lung carcinoma but down-regulated in squamous cell carcinoma. Among the 22 putative target genes, 11 showed significantly different expression levels in at least 2 of 3 pair-wise comparisons (adenocarcinoma vs. normal, squamous cell carcinoma vs. normal or small cell lung carcinoma vs. normal. Six targeted genes had strong negative correlation with the expression level of miR-375 in small cell lung carcinoma. Further investigation revealed that miR-375 directly targeted the 3'UTR of ITPKB mRNA and over-expression of miR-375 led to significantly decreased ITPKB protein level and promoted cell growth. Thus, our study demonstrates the differential expression profiles of miR-375 in 3 subtypes of lung carcinomas and finds thatmiR-375 directly targets ITPKB and promoted cell growth in SCLC cell line.

  18. Copper and resveratrol attenuates serum catalase, glutathione peroxidase, and element values in rats with DMBA-induced mammary carcinogenesis.

    Science.gov (United States)

    Skrajnowska, Dorota; Bobrowska-Korczak, Barbara; Tokarz, Andrzej; Bialek, Slawomir; Jezierska, Ewelina; Makowska, Justyna

    2013-12-01

    In this paper, a hypothesis was assessed whether or not the intoxication with copper and supplementation with copper plus resveratrol would result in changes in the activities of catalase and glutathione peroxidase and moreover if the characteristic changes would appear in concentrations of copper, iron, calcium, magnesium, and zinc in the serum of rats with chemically induced carcinogenesis. Female Sprague-Dawley rats were divided into study groups which, apart from the standard diet, were treated with copper (42.6 mg Cu/kg food as CuSO4·5H2O) or copper plus resveratrol (0.2 mg/kg body) via gavage for a period from 40 days until 20 weeks of age. In cancer groups, the rats were treated with a dose of 80 mg/body weight of 7,12-dimethyl-1,2-benz[a]anthracene (DMBA) given in rapeseed oil at 50 and 80 days of age to induce mammary carcinogenesis. The control groups included the rats kept in the same conditions and fed with the same diet as the animals from the study groups, but not DMBA-treated. The activity of catalase significantly decreased in groups of rats with mammary carcinogenesis that were supplemented with copper (p copper plus resveratrol (p cancer groups of nonsupplemented rats, the increase of glutathione peroxidase activity was observed. The process of carcinogenesis and the applied supplementation significantly altered the concentrations of trace elements in serum, in particular as concerns iron and copper. The mean serum iron levels in rats with breast cancer were significantly lower than those in the control groups (p copper levels significantly decreased in the groups of rats with mammary carcinogenesis that were supplemented with copper or copper plus resveratrol in comparison with the control groups that received the same diets (p copper and zinc/iron ratios in blood may be used as one of the prognostic factors in breast cancer research.

  19. Promoter hypermethylation of KLF4 inactivates its tumor suppressor function in cervical carcinogenesis.

    Directory of Open Access Journals (Sweden)

    Wen-Ting Yang

    Full Text Available OBJECTIVE: The KLF4 gene has been shown to be inactivated in cervical carcinogenesis as a tumor suppressor. However, the mechanism of KLF4 silencing in cervical carcinomas has not yet been identified. DNA methylation plays a key role in stable suppression of gene expression. METHODS: The methylation status of the KLF4 promoter CpG islands was analyzed by bisulfite sequencing (BSQ in tissues of normal cervix and cervical cancer. KLF4 gene expression was detected by RT-PCR, immunohistochemistry and western blot. KLF4 promoter methylation in cervical cancer cell line was determined by BSQ and methylation-specific polymerase chain reaction (MS-PCR. Cell proliferation ability was detected by cell growth curve and MTT assay. RESULTS: The methylated allele was found in 41.90% of 24 cervical cancer tissues but only in 11.11% of 11 normal cervix tissues (P<0.005. KLF4 mRNA levels were significantly reduced in cervical cancer tissues compared with normal cervix tissues (P<0.01 and KLF4 mRNA expression showed a significant negative correlation with the promoter hypermethylation (r = -0.486, P = 0.003. Cervical cancer cell lines also showed a significant negative correlation between KLF4 expression and hypermethylation. After treatment with the demethylating agent 5-Azacytidine (5-Aza, the expression of KLF4 in the cervical cancer cell lines at both mRNA and protein levels was drastically increased, the cell proliferation ability was inhibited and the chemosensitivity for cisplatin was significantly increased. CONCLUSION: KLF4 gene is inactivated by methylation-induced silencing mechanisms in a large subset of cervical carcinomas and KLF4 promoter hypermethylation inactivates the gene's function as a tumor suppressor in cervical carcinogenesis.

  20. Raman spectroscopy detects biomolecular changes associated with nanoencapsulated hesperetin treatment in experimental oral carcinogenesis

    Science.gov (United States)

    Gurushankar, K.; Gohulkumar, M.; Kumar, Piyush; Krishna, C. Murali; Krishnakumar, N.

    2016-03-01

    Recently it has been shown that Raman spectroscopy possesses great potential in the investigation of biomolecular changes of tumor tissues with therapeutic drug response in a non-invasive and label-free manner. The present study is designed to investigate the antitumor effect of hespertin-loaded nanoparticles (HETNPs) relative to the efficacy of native hesperetin (HET) in modifying the biomolecular changes during 7,12-dimethyl benz(a)anthracene (DMBA)-induced oral carcinogenesis using a Raman spectroscopic technique. Significant differences in the intensity and shape of the Raman spectra between the control and the experimental tissues at 1800-500 cm-1 were observed. Tumor tissues are characterized by an increase in the relative amount of proteins, nucleic acids, tryptophan and phenylalanine and a decrease in the percentage of lipids when compared to the control tissues. Further, oral administration of HET and its nanoparticulates restored the status of the lipids and significantly decreased the levels of protein and nucleic acid content. Treatment with HETNPs showed a more potent antitumor effect than treatment with native HET, which resulted in an overall reduction in the intensity of several biochemical Raman bands in DMBA-induced oral carcinogenesis being observed. Principal component and linear discriminant analysis (PC-LDA), together with leave-one-out cross validation (LOOCV) on Raman spectra yielded diagnostic sensitivities of 100%, 80%, 91.6% and 65% and specificities of 100%, 65%, 60% and 55% for classification of control versus DMBA, DMBA versus DMBA  +  HET, DMBA versus DMBA  +  HETNPs and DMBA  +  HET versus DMBA  +  HETNPs treated tissue groups, respectively. These results further demonstrate that Raman spectroscopy associated with multivariate statistical algorithms could be a valuable tool for developing a comprehensive understanding of the process of biomolecular changes, and could reveal the signatures of the

  1. Anticarcinogenesis effect of Gynura procumbens (Lour Merr on tongue carcinogenesis in 4NQO-induced rat

    Directory of Open Access Journals (Sweden)

    D. Agustina

    2006-09-01

    Full Text Available In Indonesia Gynura procumbens (Lour Merr leaves have been long used as various cancers medication. Many in vitro and in vivo studies have demonstrated anticarcinogenesis of ethanol extract of Gynura procumbens leaves. The aim of this study was to investigate the anticarcinogenesis of the ethanol extract of Gynura procumbens leaves on 4 nitroquinoline 1-oxide (4NQO-induced rat tongue carcinogenesis. Fifty six 4 week old male Sprague Dawley rats were used in this study and divided into 7 groups. Group 1, 2 and 3 were lingually induced by 4NQO for 8 weeks. In groups 2 and 3 the extract was given simultaneously with or after 4NQO induction finished, each for 10 weeks and 26 weeks, respectively. Groups 4, 5 and 6 were induced by 4NQO for 16 weeks. However, in groups 5 and 6 the extract was given as well simultaneously with or after the 4NQO induction, each for 18 weeks, respectively. Group 7 served as the as untreated control group. The results from microscopical assessment showed that tongue squamous cell carcinomas (SCC developed in 100% (3/3 of group 1. However, only 33.3% (2/6 and 25% (2/8 of rats in groups 2 and 3, respectively demonstrated tongue SCC. Among groups 4, 5 and 6, no significant difference of tongue SCC incidence was observed. From these results it is apparent that the ethanol extract of Gynura procumbens leaves could inhibit the progression of 4NQOinduced rat tongue carcinogenesis in the initiation phase.

  2. Significance of CpG methylation for solar UV-induced mutagenesis and carcinogenesis in skin.

    Science.gov (United States)

    Ikehata, Hironobu; Ono, Tetsuya

    2007-01-01

    Mutations detected in the p53 gene in human nonmelanoma skin cancers show a highly UV-specific mutation pattern, a dominance of C --> T base substitutions at dipyrimidine sites plus frequent CC --> TT tandem substitutions, indicating a major involvement of solar UV in the skin carcinogenesis. These mutations also have another important characteristic of frequent occurrences at CpG dinucleotide sites, some of which actually show prominent hotspots in the p53 gene. Although mammalian solar UV-induced mutation spectra were studied intensively in the aprt gene using rodent cultured cells and the UV-specific mutation pattern was confirmed, the second characteristic of the p53 mutations in human skin cancers had not been reproduced. However, studies with transgenic mouse systems developed thereafter for mutation research, which harbor methyl CpG-abundant transgenes as mutation markers, yielded complete reproductions of the situation of the human skin cancer mutations in terms of both the UV-specific pattern and the frequent occurrence at CpG sites. In this review, we evaluate the significance of the CpG methylation for solar UV mutagenesis in the mammalian genome, which would lead to skin carcinogenesis. We propose that the UV-specific mutations at methylated CpG sites, C --> T transitions at methyl CpG-associated dipyrimidine sites, are a solar UV-specific mutation signature, and have estimated the wavelength range effective for the solar-UV-specific mutation as 310-340 nm. We also recommend the use of methyl CpG-enriched sequences as mutational targets for studies on solar-UV genotoxicity for human, rather than conventional mammalian mutational marker genes such as the aprt and hprt genes.

  3. The Role of Oxidative Stress in Carcinogenesis Induced by Metals and Xenobiotics

    Directory of Open Access Journals (Sweden)

    Frank Henkler

    2010-04-01

    Full Text Available In addition to a wide range of adverse effects on human health, toxic metals such as cadmium, arsenic and nickel can also promote carcinogenesis. The toxicological properties of these metals are partly related to generation of reactive oxygen species (ROS that can induce DNA damage and trigger redox-dependent transcription factors. The precise mechanisms that induce oxidative stress are not fully understood. Further, it is not yet known whether chronic exposures to low doses of arsenic, cadmium or other metals are sufficient to induce mutations in vivo, leading to DNA repair responses and/or tumorigenesis. Oxidative stress can also be induced by environmental xenobiotics, when certain metabolites are generated that lead to the continuous release of superoxide, as long as the capacity to reduce the resulting dions (quinones into hydroquinones is maintained. However, the specific significance of superoxide-dependent pathways to carcinogenesis is often difficult to address, because formation of DNA adducts by mutagenic metabolites can occur in parallel. Here, we will review both mechanisms and toxicological consequences of oxidative stress triggered by metals and dietary or environmental pollutants in general. Besides causing DNA damage, ROS may further induce multiple intracellular signaling pathways, notably NF-kB, JNK/SAPK/p38, as well as Erk/MAPK. These signaling routes can lead to transcriptional induction of target genes that could promote proliferation or confer apoptosis resistance to exposed cells. The significance of these additional modes depends on tissue, cell-type and is often masked by alternate oncogenic mechanisms being activated in parallel.

  4. Histopathological and in vivo evidence of regucalcin as a protective molecule in mammary gland carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Ricardo; Vaz, Cátia V.; Maia, Cláudio J. [CICS-UBI, Health Sciences Research Centre, University of Beira Interior, Covilhã (Portugal); Gomes, Madalena [IPATIMUP, Institute of Molecular Pathology and Immunology, University of Porto, Porto (Portugal); Gama, Adelina [Department of Veterinary Sciences, Animal and Veterinary Science Research Center (CECAV), University of Trás-os-Montes and Alto Douro (UTAD) (Portugal); Alves, Gilberto; Santos, Cecília R. [CICS-UBI, Health Sciences Research Centre, University of Beira Interior, Covilhã (Portugal); Schmitt, Fernando [IPATIMUP, Institute of Molecular Pathology and Immunology, University of Porto, Porto (Portugal); Medical Faculty, University of Porto, Porto (Portugal); Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto (Canada); Department of Pathology, University Health Network, Toronto (Canada); Socorro, Sílvia, E-mail: ssocorro@fcsaude.ubi.pt [CICS-UBI, Health Sciences Research Centre, University of Beira Interior, Covilhã (Portugal)

    2015-01-15

    Regucalcin (RGN) is a calcium-binding protein, which has been shown to be underexpressed in cancer cases. This study aimed to determine the association of RGN expression with clinicopathological parameters of human breast cancer. In addition, the role of RGN in malignancy of mammary gland using transgenic rats overexpressing the protein (Tg-RGN) was investigated. Wild-type (Wt) and Tg-RGN rats were treated with 7,12-dimethylbenz[α]anthracene (DMBA). Carcinogen-induced tumors were histologically classified and the Ki67 proliferation index was estimated. Immunohistochemistry analysis showed that RGN immunoreactivity was negatively correlated with the histological grade of breast infiltrating ductal carcinoma suggesting that progression of breast cancer is associated with loss of RGN. Tg-RGN rats displayed lower incidence of carcinogen-induced mammary gland tumors, as well as lower incidence of invasive forms. Moreover, higher proliferation was observed in non-invasive tumors of Wt animals comparatively with Tg-RGN. Overexpression of RGN was associated with diminished expression of cell-cycle inhibitors and increased expression of apoptosis inducers. Augmented activity of apoptosis effector caspase-3 was found in the mammary gland of Tg-RGN. RGN overexpression protected from carcinogen-induced mammary gland tumor development and was linked with reduced proliferation and increased apoptosis. These findings indicated the protective role of RGN in the carcinogenesis of mammary gland. - Highlights: • RGN immunoreactivity was negatively correlated with breast cancer differentiation. • Transgenic overexpression of RGN diminished incidence of carcinogen-induced tumors. • Transgenic overexpression of RGN restricted proliferation and fostered apoptosis. • RGN has a protective role in the carcinogenesis of mammary gland.

  5. Beclin 1 Expression is Closely Linked to Colorectal Carcinogenesis and Distant Metastasis of Colorectal Carcinoma

    Directory of Open Access Journals (Sweden)

    Mei-Ying Zhang

    2014-08-01

    Full Text Available Beclin 1 participates in development, autophagy, differentiation, anti- apoptosis, neurodegeneration, tumorigenesis and cancer progression. The roles of Beclin 1 in colorectal carcinogenesis and its subsequent progression are still unclear. Here, the mRNA and protein expression of Beclin 1 were determined in colorectal carcinoma and matched mucosa by Reverse transcriptase-polymerase chain reaction and Western blot. Immunohistochemistry and in situ hybridization (ISH were performed on tissue microarryer with colorectal carcinoma, adenoma and mucosa. The expression of Beclin 1 mRNA and protein was found to be higher in colorectal carcinoma than matched mucosa by real-time PCR and Western blot (p < 0.05. According to the ISH data, Beclin 1 expression was lower in colorectal non-neoplastic mucosa (NNM than adenoma and carcinoma (p < 0.05. Immunohistochemically, primary carcinoma showed stronger Beclin 1 expression than NNM and metastatic carcinoma in the liver (p < 0.05. Beclin 1 protein expression was negatively related to liver and distant metastasis (p < 0.05, but not correlated with age, sex, depth of invasion, lymphatic or venous invasion, lymph node metastasis, tumor-node-metastasis (TNM staging, differentiation or serum carcinoembryonic antigen (CEA concentration (p > 0.05. Survival analysis indicated that Beclin 1 expression was not linked to favorable prognosis of the patients with colorectal carcinoma (p > 0.05. Cox’s model indicated that depth of invasion and distant metastasis were independent prognostic factors for colorectal carcinomas (p < 0.05. It was suggested that Beclin 1 expression is closely linked to colorectal carcinogenesis and distant metastasis of colorectal carcinoma.

  6. Age-Related Differences in Susceptibility to Carcinogenesis: A Quantitative Analysis of Empirical Animal Bioassay Data

    Science.gov (United States)

    Hattis, Dale; Goble, Robert; Russ, Abel; Chu, Margaret; Ericson, Jen

    2004-01-01

    In revising cancer risk assessment guidelines, the U.S. Environmental Protection Agency (EPA) analyzed animal cancer bioassay data over different periods of life. In this article, we report an improved analysis of these data (supplemented with some chemical carcinogenesis observations not included in the U.S. EPA’s original analysis) and animal bioassay studies of ionizing radiation. We use likelihood methods to avoid excluding cases where no tumors were observed in specific groups. We express dosage for animals of different weights on a metabolically consistent basis (concentration in air or food, or per unit body weight to the three-quarters power). Finally, we use a system of dummy variables to represent exposures during fetal, preweaning, and weaning–60-day postnatal periods, yielding separate estimates of relative sensitivity per day of dosing in these intervals. Central estimate results indicate a 5- to 60-fold increased carcinogenic sensitivity in the birth–weaning period per dose ÷ (body weight0.75-day) for mutagenic carcinogens and a somewhat smaller increase—centered about 5-fold—for radiation carcinogenesis per gray. Effects were greater in males than in females. We found a similar increased sensitivity in the fetal period for direct-acting nitrosoureas, but no such increased fetal sensitivity was detected for carcinogens requiring metabolic activation. For the birth–weaning period, we found an increased sensitivity for direct administration to the pups similar to that found for indirect exposure via lactation. Radiation experiments indicated that carcinogenic sensitivity is not constant through the “adult” period, but the dosage delivered in 12- to 21-month-old animals appears a few-fold less effective than the comparable dosage delivered in young adults (90–105 days of age). PMID:15289159

  7. Deferasirox induces mesenchymal-epithelial transition in crocidolite-induced mesothelial carcinogenesis in rats.

    Science.gov (United States)

    Nagai, Hirotaka; Okazaki, Yasumasa; Chew, Shan Hwu; Misawa, Nobuaki; Yasui, Hiroyuki; Toyokuni, Shinya

    2013-11-01

    Asbestos was used worldwide in huge quantities in the past century. However, because of the unexpected carcinogenicity to mesothelial cells with an extremely long incubation period, many countries face this long-lasting social problem. Mesothelioma is often diagnosed in an advanced stage, for which no effective therapeutic protocols are yet established. We previously reported on the basis of animal experiments that the major pathology in asbestos-induced mesothelial carcinogenesis is local iron overload. Here, we undertook to find an effective strategy to prevent, delay, or lower the malignant potential of mesothelioma during asbestos-induced carcinogenesis. We used intraperitoneal injections of crocidolite to rats. We carried out a 16-week study to seek the maximal-tolerated intervention for iron reduction via oral deferasirox administration or intensive phlebotomy. Splenic iron deposition was significantly decreased with either method, and we found that Perls' iron staining in spleen is a good indicator for iron reduction. We injected a total of 10 mg crocidolite at the age of six weeks, and the preventive measures were via repeated oral administration of 25 to 50 mg/kg/d deferasirox or weekly to bimonthly phlebotomy of 4 to 10 mL/kg/d. The animals were observed until 110 weeks. Deferasirox administration significantly increased the fraction of less malignant epithelioid subtype. Although we found a slightly prolonged survival in deferasirox-treated female rats, larger sample size and refinement of the current protocol are necessary to deduce the cancer-preventive effects of deferasirox. Still, our results suggest deferasirox serves as a potential preventive strategy in people already exposed to asbestos via iron reduction.

  8. Epithelial nuclear factor-κB signaling promotes lung carcinogenesis via recruitment of regulatory T lymphocytes.

    Science.gov (United States)

    Zaynagetdinov, R; Stathopoulos, G T; Sherrill, T P; Cheng, D-S; McLoed, A G; Ausborn, J A; Polosukhin, V V; Connelly, L; Zhou, W; Fingleton, B; Peebles, R S; Prince, L S; Yull, F E; Blackwell, T S

    2012-06-28

    The mechanisms by which chronic inflammatory lung diseases, particularly chronic obstructive pulmonary disease, confer enhanced risk for lung cancer are not well-defined. To investigate whether nuclear factor (NF)-κB, a key mediator of immune and inflammatory responses, provides an interface between persistent lung inflammation and carcinogenesis, we utilized tetracycline-inducible transgenic mice expressing constitutively active IκB kinase β in airway epithelium (IKTA (IKKβ trans-activated) mice). Intraperitoneal injection of ethyl carbamate (urethane), or 3-methylcholanthrene (MCA) and butylated hydroxytoluene (BHT) was used to induce lung tumorigenesis. Doxycycline-treated IKTA mice developed chronic airway inflammation and markedly increased numbers of lung tumors in response to urethane, even when transgene expression (and therefore epithelial NF-κB activation) was begun after exposure to carcinogen. Studies using a separate tumor initiator/promoter model (MCA+BHT) indicated that NF-κB functions as an independent tumor promoter. Enhanced tumor formation in IKTA mice was preceded by increased proliferation and reduced apoptosis of alveolar epithelium, resulting in increased formation of premalignant lesions. Investigation of inflammatory cells in lungs of IKTA mice revealed a substantial increase in macrophages and lymphocytes, including functional CD4+/CD25+/FoxP3+ regulatory T lymphocytes (Tregs). Importantly, Treg depletion using repetitive injections of anti-CD25 antibodies limited excessive tumor formation in IKTA mice. At 6 weeks following urethane injection, antibody-mediated Treg depletion in IKTA mice reduced the number of premalignant lesions in the lungs in association with an increase in CD8 lymphocytes. Thus, persistent NF-κB signaling in airway epithelium facilitates carcinogenesis by sculpting the immune/inflammatory environment in the lungs.

  9. Methylation-mediated transcriptional repression of microRNAs during cervical carcinogenesis

    Science.gov (United States)

    Wilting, Saskia M.; Verlaat, Wina; Jaspers, Annelieke; Makazaji, Nour A.; Agami, Reuven; Meijer, Chris J.L.M.; Snijders, Peter J.F.

    2013-01-01

    Deregulated expression of microRNAs (miRNAs) is common and biologically relevant in cervical carcinogenesis and appears only partly related to chromosomal changes. We recently identified 32 miRNAs showing decreased expression in high-grade cervical intraepithelial neoplasia (CIN) and carcinomas not associated with a chromosomal loss, 6 of which were located within a CpG island. This study aimed to investigate to what extent these miRNAs are subject to DNA methylation-mediated transcriptional repression in cervical carcinogenesis.   Methylation-specific PCR (MSP) analysis on a cell line panel representing different stages of human papillomavirus (HPV) induced transformation revealed an increase in methylation of hsa-miR-149, -203 and -375 with progression to malignancy, whereas expression of these miRNAs was restored upon treatment with a demethylating agent. All three miRNAs showed significantly increased levels of methylation in cervical carcinomas, whereas methylation levels of hsa-miR-203 and -375 were also significantly increased in high-grade CIN. A pilot analysis showed that increased hsa-miR-203 methylation was also detectable in HPV-positive cervical scrapes of women with high-grade CIN compared with controls. Similar to recent findings on hsa-miR-375, ectopic expression of hsa-miR-203 in cervical cancer cells decreased both the proliferation rate and anchorage independent growth. We found evidence for methylation-mediated transcriptional repression of hsa-miR-149, -203 and -375 in cervical cancer. Methylation of the latter two was already apparent in precancerous lesions and represent functionally relevant events in HPV-mediated transformation. Increased hsa-miR-203 methylation was detectable in scrapes of women with high-grade CIN, indicating that methylated miRNAs may provide putative markers to assess the presence of (pre)cancerous lesions. PMID:23324622

  10. KALIMER design concept report

    Energy Technology Data Exchange (ETDEWEB)

    Park, Chang Kyu; Kim, Young Cheol; Kim, Young In; Kim, Young Gyun; Kim, Eui Kwang; Song, Hoon; Chung, Hyun Tai; Hwang, Woan; Nam, Cheol; Sim Yoon Sub; Kim, Yeon Sik; Wim Myung Whan; Min, Byung Tae; Yoo, Bong; Lee, Jae Han; Lee, Hyeong Yeon; Kim, Jong Bum; Koo, Gyeong Hoi; Ham, Chang Shik; Kwon, Kee Choon; Kim, Jung Taek; Park, Jae Chang; Lee, Jung Woon; Lee, Yong Hee; Kim, Chang Hwoi; Sim, Bong Shick; Hahn, Do Hee; Choi, Jong Hyeun; Kwon, Sang Woon

    1997-07-01

    KAERI is working for the development of KALIMER and work is being done for methodology development, experimental facility set up and design concept development. The development target of KALIMER has been set as to make KALIMER safer, more economic, more resistant to nuclear proliferation, and yield less impact on the environment. To achieve the target, study has been made for setting up the design concept of KALIMER including the assessment of various possible design alternatives. This report is the results of the study for the KALIMER concept study and describes the design concept of KALIMER. The developed design concept study and describes the design concept of KALIMER. The developed design concept is to be used as the starting point of the next development phase of conceptual design and the concept will be refined and modified in the conceptual design phase. The scope of the work has been set as the NSSS and essential BOP systems. For systems, NSSS and functionally related major BOP are covered. Sizing and specifying conceptual structure are covered for major equipment. Equipment and piping are arranged for the parts where the arrangement is critical in fulfilling the foresaid intention of setting up the KALIMER design concept. This report consists of 10 chapters. Chapter 2 is for the top level design requirements of KALIMER and it serves as the basis of KALIMER design concept development. Chapter 3 summarizes the KALIMER concept and describes the general design features. The remaining chapters are for specific systems. (author). 29 tabs., 37 figs.

  11. Molecular thermodynamics of nonideal fluids

    CERN Document Server

    Lee, Lloyd L

    2013-01-01

    Molecular Thermodynamics of Nonideal Fluids serves as an introductory presentation for engineers to the concepts and principles behind and the advances in molecular thermodynamics of nonideal fluids. The book covers related topics such as the laws of thermodynamics; entropy; its ensembles; the different properties of the ideal gas; and the structure of liquids. Also covered in the book are topics such as integral equation theories; theories for polar fluids; solution thermodynamics; and molecular dynamics. The text is recommended for engineers who would like to be familiarized with the concept

  12. Molecular physics

    CERN Document Server

    Williams, Dudley

    2013-01-01

    Methods of Experimental Physics, Volume 3: Molecular Physics focuses on molecular theory, spectroscopy, resonance, molecular beams, and electric and thermodynamic properties. The manuscript first considers the origins of molecular theory, molecular physics, and molecular spectroscopy, as well as microwave spectroscopy, electronic spectra, and Raman effect. The text then ponders on diffraction methods of molecular structure determination and resonance studies. Topics include techniques of electron, neutron, and x-ray diffraction and nuclear magnetic, nuclear quadropole, and electron spin reson

  13. Novel concepts in male infertility

    Directory of Open Access Journals (Sweden)

    Sandro C. Esteves

    2011-02-01

    Full Text Available Extraordinary advances have been achieved in the field of male infertility in the last decades. There are new concepts in sperm physiology and several modern tools for the assessment of spermatogenesis kinetics in vivo. New tests using molecular biology and DNA damage assays allow the clinician to correctly diagnose men so far classified as having idiopathic male infertility. In the field of treatment, microsurgery has increased success rates either for reconstruction of the reproductive tract or the retrieval of spermatozoa for assisted conception. Emerging evidence suggests that life-style and environmental conditions are of utmost importance in male fertility and subfertility. This review discusses several concepts that have changed over the last years, such as the duration of the spermatogenic cycle in humans, Y-chromosome infertility, the reproductive potential of non-mosaic Klinefelter syndrome men, the impact of paternal age and sperm DNA in male infertility, the role of antioxidants in the treatment of infertile men, the predictive factors and techniques for sperm retrieval in non-obstructive azoospermia, and the microsurgical treatment of clinical varicoceles. Whenever possible, levels of evidence are provided as suggested by the Oxford Center of Evidence-based Medicine.

  14. The concept of cluster

    DEFF Research Database (Denmark)

    Laursen, Lea Louise Holst; Møller, Jørgen

    2013-01-01

    villages in order to secure their future. This paper will address the concept of cluster-villages as a possible approach to strengthen the conditions of contemporary Danish villages. Cluster-villages is a concept that gather a number of villages in a network-structure where the villages both work together...... to forskellige positioner ser vi en ny mulighed for landsbyudvikling, som vi kalder Clustervillages. In order to investigate the potentials and possibilities of the cluster-village concept the paper will seek to unfold the concept strategically; looking into the benefits of such concept. Further, the paper seeks...... to inscribe the concept into the existing debate regarding villages in the rural districts....

  15. Resilience - A Concept

    Science.gov (United States)

    2016-04-05

    same construct. If resil- iency of a system equates to the health of a person , then maybe there should be resiliency indices similar to health ... Image designed by Diane Fleischer Resilience—A CONCEPT Col Dennis J. Rensel, USAF (Ret.) Resilience takes on many definitions and ideas depending...as biomedical indices provide an indication, a concept of a person’s health . This process or concept of assessing one’s health can be equated to

  16. Fundamental concepts of geometry

    CERN Document Server

    Meserve, Bruce E

    1983-01-01

    Demonstrates relationships between different types of geometry. Provides excellent overview of the foundations and historical evolution of geometrical concepts. Exercises (no solutions). Includes 98 illustrations.

  17. Condutância molecular e biomolecular

    Directory of Open Access Journals (Sweden)

    Gama A. Arnóbio S. da

    2000-01-01

    Full Text Available The concept of molecular conductance is discussed in terms of the propagation of an electronic interaction, between electron donor and acceptor groups, through the bonds of a molecular structure where these groups are embedded. The electronic interaction propagation is described by a Green's function matrix element, in a donor-bridge-acceptor molecular system reduced to a two-level representation.

  18. ICRP Publication 131: Stem Cell Biology with Respect to Carcinogenesis Aspects of Radiological Protection.

    Science.gov (United States)

    Niwa, O; Barcellos-Hoff, M H; Globus, R K; Harrison, J D; Hendry, J H; Jacob, P; Martin, M T; Seed, T M; Shay, J W; Story, M D; Suzuki, K; Yamashita, S

    2015-12-01

    This report provides a review of stem cells/progenitor cells and their responses to ionising radiation in relation to issues relevant to stochastic effects of radiation that form a major part of the International Commission on Radiological Protection's system of radiological protection. Current information on stem cell characteristics, maintenance and renewal, evolution with age, location in stem cell 'niches', and radiosensitivity to acute and protracted exposures is presented in a series of substantial reviews as annexes concerning haematopoietic tissue, mammary gland, thyroid, digestive tract, lung, skin, and bone. This foundation of knowledge of stem cells is used in the main text of the report to provide a biological insight into issues such as the linear-no-threshold (LNT) model, cancer risk among tissues, dose-rate effects, and changes in the risk of radiation carcinogenesis by age at exposure and attained age. Knowledge of the biology and associated radiation biology of stem cells and progenitor cells is more developed in tissues that renew fairly rapidly, such as haematopoietic tissue, intestinal mucosa, and epidermis, although all the tissues considered here possess stem cell populations. Important features of stem cell maintenance, renewal, and response are the microenvironmental signals operating in the niche residence, for which a well-defined spatial location has been identified in some tissues. The identity of the target cell for carcinogenesis continues to point to the more primitive stem cell population that is mostly quiescent, and hence able to accumulate the protracted sequence of mutations necessary to result in malignancy. In addition, there is some potential for daughter progenitor cells to be target cells in particular cases, such as in haematopoietic tissue and in skin. Several biological processes could contribute to protecting stem cells from mutation accumulation: (a) accurate DNA repair; (b) rapidly induced death of injured stem cells

  19. Role of inflammation in the carcinogenesis of colorectal cancer%炎症在结直肠癌发生中的作用机制

    Institute of Scientific and Technical Information of China (English)

    徐春晓; 张艳; 朱益民

    2013-01-01

    结直肠癌是最常见的恶性肿瘤之一.流行病学和分子生物学研究表明炎症和结直肠癌发病之间存在着密切联系.目前关于炎症和结直肠癌发病有关的分子机制研究已有不少报道,但是尚不能完全阐释.若能发现结直肠癌发病的重要炎症基础,则可能为结直肠癌的预防和治疗提供新靶点.本文系统地对结直肠癌发病相关的炎症机制进行综述,以期为以后的进一步研究提供线索.%Colorectal cancer is one of the most common malignant tumors.Previous epidemiological and molecular biological studies have suggested that inflammation plays a pivotal role in the pathogenesis of colorectal cancer.Moreover,many studies have been focused on molecular pathways of inflammation in colorectal cancer.However,the explicit mechanisms involved remain to be fully elucidated.The identification of the key inflammatory mechanisms may provide new targets for intervention and treatment of colorectal cancer.Here we reviewed the inflammatory mechanisms relevant to the carcinogenesis of colorectal cancer,hoping to cast new lights on future research.

  20. Hedging structured concepts

    NARCIS (Netherlands)

    Koolen, W.M.; Warmuth, M.K.; Kivinen, J.; Kalai, A.T.; Mohri, M.

    2010-01-01

    We develop an online algorithm called Component Hedge for learning structured concept classes when the loss of a structured concept sums over its components. Example classes include paths through a graph (composed of edges) and partial permutations (composed of assignments). The algorithm maintains

  1. Modeling concept drift

    DEFF Research Database (Denmark)

    Borchani, Hanen; Martinez, Ana Maria; Masegosa, Andrés R.

    2015-01-01

    An often used approach for detecting and adapting to concept drift when doing classification is to treat the data as i.i.d. and use changes in classification accuracy as an indication of concept drift. In this paper, we take a different perspective and propose a framework, based on probabilistic ...

  2. Kierkegaard's concepts: Hypocrisy

    DEFF Research Database (Denmark)

    Fauth Hansen, Thomas Martin

    2014-01-01

    Kierkegaard’s Concepts is a comprehensive, multi-volume survey of the key concepts and categories that inform Kierkegaard’s writings. Each article is a substantial, original piece of scholarship, which discusses the etymology and lexical meaning of the relevant Danish term, traces the development...

  3. Tools and Concepts.

    Science.gov (United States)

    Artis, Margaret, Ed.; And Others

    This guide provides enrichment for students to develop tools and concepts used in various areas of mathematics. The first part presents arithmetic progressions, geometric progressions, and harmonic progression. In the second section, the concept of mathematic induction is developed from intuitive induction, using concrete activities, to the…

  4. Threshold Concepts in Economics

    Science.gov (United States)

    Shanahan, Martin

    2016-01-01

    Purpose: The purpose of this paper is to examine threshold concepts in the context of teaching and learning first-year university economics. It outlines some of the arguments for using threshold concepts and provides examples using opportunity cost as an exemplar in economics. Design/ Methodology/Approach: The paper provides an overview of the…

  5. The LDC detector concept

    Indian Academy of Sciences (India)

    Ties Behnke; LDC Concept Group

    2007-11-01

    In preparation of the experimental program at the international linear collider (ILC), the large detector concept (LDC) is being developed. The main points of the LDC are a large volume gaseous tracking system, combined with high precision vertex detector and an extremely granular calorimeter. The main design force behind the LDC is the particle flow concept.

  6. Inhibitory effects of Zengshengping fractions on DMBA-induced buccal pouch carcinogenesis in hamsters

    Institute of Scientific and Technical Information of China (English)

    GUAN Xiao-bing; SUN Zheng; CHEN Xiao-xin; WU Hong-ru; ZHANG Xin-yan

    2012-01-01

    Background Zengshengping (ZSP) tablets had inhibitory effects on oral precancerous lesions by reducing the incidence of oral cancer.However,the severe liver toxicity caused by systemic administration of ZSP limits the long-term use of this anti-cancer drug.The purpose of this study was to evaluate the tumor inhibitory effects due to the topical application of extracts from ZSP,a Chinese herbal drug,on 7,12-dimethlbenz(a)anthracene (DMBA) induced oral tumors in hamsters.The study also investigated the anti-cancer mechanisms of the ZSP extracts on oral carcinogenesis.Methods DMBA (0.5%) was applied topically to the buccal pouches of Syrian golden hamsters (6-8 weeks old) three times per week for six weeks in order to induce the development of oral tumors.Different fractions of ZSP were either applied topically to the oral tumor lesions or fed orally at varying dosages to animals with oral tumors for 18 weeks.Tumor volume was measured by histopathological examination.Tumor cell proliferation was evaluated by counting BrdU labeled cells and by Western blotting for mitogen-activated protein kinase (MAPK) protein levels.The protein levels of apoptosis marker Caspase-3 and regulator Bcl-2 protein were also measured by Western blotting.Results Topical application of DMBA to the left pouch of hamsters induced oral tumor formation.Animals treated with DMBA showed a loss in body weight while animals treated with ZSP maintained normal body weights.Both the ZSP n-butanol fraction and water fraction significantly reduced tumor volume by 32.6% (P <0.01) and 22.9% (P <0.01)respectively.Topical application of ZSP also markedly decreased the BrdU-positive cell numbers in oral tumor lesions and reduced the expression level of MAPK.In addition,ZSP promoted tumor cell apoptosis by increasing Caspase-3 expression but decreasing Bcl-2 protein production.Conclusion The n-butanol and water fractions of ZSP are effective at inhibiting tumor cell proliferation and stimulating

  7. Potential effect of hepatitis C Virus non-structural protein 4B on liver carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    Xia Chen; Changping Li; Zhongqiong Wang; Guanghong DU

    2006-01-01

    Objective: To investigate the effect of hepatitis C virus non-structural protein 4B(HCV NS4B) on c-Myc, P53,ras gene expression' and apoptosis in hepatic cells and study the possible role that NS4B played in the carcinogenesis of hepatoma. Methods: The recombinant plasmid(PCXN2-NS4B, PCXN2-P53) and the empty vector were transfected or co-transfected into Chang liver cells with liposome. Screening was performed with G418. Plasmid mRNA was detected by RT-PCR. The pro tein expressions of c-Myc and ras genes were analyzed by immunocytochemistry. The expressions of wild-type P53 (wtp53) gene were detected by in situ hybridization. TUNEL(flow cytometry) was used for assessing the rate of apoptosis. Results :No expression of c-Myc gene was found in PCXN2 group. The expression of c-Myc gene in NS4B group was 21.3% ± 1.2%. The ex pression of ras gene in PCXN2 group was lower than that in NS4B group. Compared with PCXN2 group, the expression of P53mRNA was not promoted or inhibited in NS4B group. But the expression of P53 mRNA in NS4B-P53 group was lower than that in P53 group. In PCXN2, NS4B, P53 and NS4B-P53 group, the rates of apoptosis were 17.02% ± 1.24%, 11.94% ± 2.24%,25.84% ± 3.49% and 18.34% ± 1.55% respectively. Conclusion:HCV NS4B induces the expression of c-Myc and ras gene. HCV NS4B may play a role in the inhibition of cell death through P53-dependent manner. Results from this study suggested that HCV NS4B might conuibute to the viral carcinogenesis.

  8. Role of EZH2 protein expression in gastric carcinogenesis among Asians: a meta-analysis.

    Science.gov (United States)

    Guo, Lin; Yang, Teng-Fei; Liang, Shi-Chao; Guo, Ji-Xiang; Wang, Qiang

    2014-07-01

    The present meta-analysis aggregated the results of relevant studies to identify the role of zeste homolog 2 (EZH2) expression in gastric carcinogenesis among Asians. Related articles were found by searching the following electronic databases without language restrictions: PubMed, SpringerLink, Karger Medical and Scientific Publishers, Chinese Biomedical Database (CBM), Chinese National Knowledge Infrastructure (CNKI), and Google Scholar. Meta-analysis was performed using STATA statistical software. Crude odds ratios (ORs) or hazard ratios (HRs) with their corresponding 95 % confidence interval (95 % CI) were calculated. Ten relevant studies, which enrolled a total of 872 gastric cancer patients, were selected for statistical analysis. The most important findings of our meta-analysis was that cancer tissues exhibited higher expression levels of EZH2 protein than normal, adjacent and benign tissues (cancer tissues vs normal tissues: OR = 32.15, 95 % CI 22.58 ~ 45.79, P < 0.001; cancer tissues vs adjacent tissues: OR = 16.10, 95 % CI 11.35 ~ 22.84, P < 0.001; cancer tissues vs benign tissues: OR = 2.66, 95 % CI 1.89 ~ 3.75, P < 0.001; respectively). Furthermore, we observed positive correlations between EZH2 expression and the TNM stage (OR = 2.86, 95 % CI 1.72 ~ 4.75, P < 0.001) as well as lymph node metastasis (OR = 3.02, 95 % CI 2.01 ~ 4.53, P < 0.001) of patients with gastric carcinoma. The correlation between EZH2 expression and gastric cancer prognosis was also evaluated in the meta-analysis. Statistical analysis demonstrated that the overall survival (OS) of EZH2-negative patients was shorter than that of patients with positive expressions of EZH2 (HR = 0.54, 95 % CI = 0.05 ~ 1.03, P = 0.032). Our meta-analysis confirmed the view that EZH2 expression might participate in the development of gastric carcinogenesis. Thus, EZH2 protein may be a valuable biomarker for the diagnosis and prognosis of gastric cancer.

  9. Human colon carcinogenesis is associated with increased interleukin-17-driven inflammatory responses

    Directory of Open Access Journals (Sweden)

    Xie Z

    2015-03-01

    Full Text Available Zhaohui Xie,1 Yine Qu,2 Yanli Leng,2 Wenxiu Sun,2 Siqi Ma,2 Jingbo Wei,2 Jiangong Hu,3 Xiaolan Zhang1 1Department of Gastroenterology, Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, People’s Republic of China; 2Department of Histology and Embryology, Hebei United University School of Basic Medicine, Tangshan, Hebei, People’s Republic of China; 3Department of Pathology, the Second Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, People’s Republic of China Abstract: Inflammation is known to contribute to carcinogenesis in human colorectal cancer. Proinflammatory cytokine interleukin-17 (IL-17 or IL-17A has been shown to play a critical role in colon carcinogenesis in mouse models. However, few studies have investigated IL-17A in human colon tissues. In the present study, we assessed IL-17-driven inflammatory responses in 17 cases of human colon adenocarcinomas, 16 cases of human normal colon tissues adjacent to the resected colon adenocarcinomas, ten cases of human ulcerative colitis tissues from biopsies, and eight cases of human colon polyps diagnosed as benign adenomas. We found that human colon adenocarcinomas contained the highest levels of IL-17A cytokine, which was significantly higher than the IL-17A levels in the adenomas, ulcerative colitis, and normal colon tissues (P<0.01. The levels of IL-17 receptor A (IL-17RA were also the highest in human colon adenocarcinomas, followed by adenomas and ulcerative colitis. The increased levels of IL-17A and IL-17RA were accompanied with increased IL-17-driven inflammatory responses, including activation of extracellular signal-regulated kinase (ERK1/2 and c-Jun N-terminal kinase (JNK pathways, increase in expression of matrix metalloproteinase (MMP9, MMP7, MMP2, B-cell lymphoma (Bcl-2, and cyclin D1, decrease in Bcl-2-associated X protein (BAX expression, and increase in vascular endothelial growth factor (VEGF and VEGF receptor (VEGFR expression that

  10. Multistage Carcinogenesis Modelling of Low and Protracted Radiation Exposure for Risk Assessment

    Science.gov (United States)

    Brugmans, M. J. P.; Bijwaard, H.

    Exposure to cosmic radiation in space poses an increased risk for radiation-induced cancer later in life. Modelling is essential to quantify these excess risks from low and protracted exposures to a mixture of radiation types, since they cannot be determined directly in epidemiological studies. Multistage carcinogenesis models provide a mechanistic basis for the extrapolation of epidemiological data to the regime that is relevant for radiation protection. In recent years, we have exploited the well-known two-mutation carcinogenesis model to bridge the gap between radiobiology and epidemiology. We have fitted this model to a number of animal and epidemiological data sets, using dose-response relationships for the mutational steps that are well established in cellular radiobiology. The methodology and implications for radiation risks are illustrated with analyses of two radiation-induced tumours: bone cancer from internal (high-LET and low-LET) emitters and lung cancer after radon exposure. For the risks of bone-seeking radionuclides (Ra-226, Sr-90, Pu-239), model fits to beagle data show that the dose-effect relationship for bone cancer at low intakes is linear-quadratic. This is due to a combination of equally strong linear dose-effects in the two subsequent mutational steps in the model. This supra-linear dose-effect relationship is also found in a model analysis of bone cancer in radium dial painters. This implies that at low intakes the risks from bone seekers are significantly lower than estimated from a linear extrapolation from high doses. Model analyses of radon-exposed rats and uranium miners show that lung-cancer induction is dominated by a linear radiation effect in the first mutational step. For two miner cohorts with significantly different lung cancer baselines a uniform description of the effect of radon is obtained in a joint analysis. This demonstrates the possibility to model risk transfer across populations. In addition to biologically based risk

  11. Low ABCB1 gene expression is an early event in colorectal carcinogenesis.

    Directory of Open Access Journals (Sweden)

    Vibeke Andersen

    Full Text Available The ABCB1/MDR1 gene product ABCB1/P-glycoprotein is implicated in the development of colorectal cancer (CRC. NFKB1 encodes transcription factors regulating expression of a number of genes including ABCB1. We have previously found association between the ABCB1 C-rs3789243-T polymorphism and CRC risk and interactions between the ABCB1 C-rs3789243-T and C3435T polymorphisms and meat intake in relation to CRC risk (Andersen, BMC Cancer, 2009, 9, 407. ABCB1 and NFKB1 mRNA levels were assessed in intestinal tissue from 122 CRC cases, 101 adenoma cases (12 with severe dysplasia, 89 with mild-moderate dysplasia and from 18 healthy individuals, together with gene polymorphisms in ABCB1 and NFKB1. ABCB1 mRNA levels were highest in the healthy individuals and significantly lower in mild/moderate and severe dysplasia tissue (P<0.05 for both, morphologically normal tissues close to the tumour (P<0.05, morphologically normal tissue at a distance from the tumour (P<0.05 and CRC tissue (P<0.001. Furthermore, ABCB1 mRNA levels were lower in adenomas and carcinomas compared to morphologically normal tissue from the same individuals (P<0.01. The ABCB1 C-rs3789243-T and NFKB1 -94ins/del homozygous variant genotypes were associated with low ABCB1 mRNA levels in morphologically normal sigmoid tissue from adenoma cases (P<0.05 for both. NFKB1 mRNA levels were lower in both tumour and normal tissue from cancer patients (P<0.001 as compared to healthy individuals but we were unable to show association between NFKB1 -94ins/del genotype and NFKB1 mRNA levels. This study suggests that low ABCB1 mRNA levels are an early event in CRC development and that the two polymorphisms affect ABCB1 mRNA levels whereas low NFKB1 mRNA levels occur later in carcinogenesis. Low ABCB1 protein levels may promote colorectal carcinogenesis through increasing intracellular exposure to carcinogenic ABCB1 substrates.

  12. Role of infectious agents in the carcinogenesis of brain and head and neck cancers

    Directory of Open Access Journals (Sweden)

    Alibek Kenneth

    2013-02-01

    Full Text Available Abstract This review concentrates on tumours that are anatomically localised in head and neck regions. Brain cancers and head and neck cancers together account for more than 873,000 cases annually worldwide, with an increasing incidence each year. With poor survival rates at late stages, brain and head and neck cancers represent serious conditions. Carcinogenesis is a multi-step process and the role of infectious agents in this progression has not been fully identified. A major problem with such research is that the role of many infectious agents may be underestimated due to the lack of or inconsistency in experimental data obtained globally. In the case of brain cancer, no infection has been accepted as directly oncogenic, although a number of viruses and parasites are associated with the malignancy. Our analysis of the literature showed the presence of human cytomegalovirus (HCMV in distinct types of brain tumour, namely glioblastoma multiforme (GBM and medulloblastoma. In particular, there are reports of viral protein in up to 100% of GBM specimens. Several epidemiological studies reported associations of brain cancer and toxoplasmosis seropositivity. In head and neck cancers, there is a distinct correlation between Epstein-Barr virus (EBV and nasopharyngeal carcinoma (NPC. Considering that almost every undifferentiated NPC is EBV-positive, virus titer levels can be measured to screen high-risk populations. In addition there is an apparent association between human papilloma virus (HPV and head and neck squamous cell carcinoma (HNSCC; specifically, 26% of HNSCCs are positive for HPV. HPV type 16 was the most common type detected in HNSCCs (90% and its dominance is even greater than that reported in cervical carcinoma. Although there are many studies showing an association of infectious agents with cancer, with various levels of involvement and either a direct or indirect causative effect, there is a scarcity of articles covering the role of

  13. Adenovirus-expressed preS2 antibody inhibits hepatitis B virus infection and hepatic carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    Qian Zhang; Zhi-Qing Li; Hu Liu; Jia-He Yang

    2012-01-01

    AIM: To investigate the inhibitory effect of hepatitis B virus (HBV) preS2 antibody (preS2Ab) against HBV infection and HBV-associated hepatic carcinogenesis. METHODS: An adenoviral vector carrying the fulllength light and heavy chains of the HBV preS2Ab gene, Ad315-preS2Ab, was constructed. Enzyme linked immunosorbent assay (ELISA) and Western blotting analyses were used to determine the preS2Ab expression levels in vitro . Immunofluorescent techniques were used to examine the binding affinity between the expressed HBV preS2Ab and HBV-positive liver cells. ELISAs were also used to determine hepatitis B surface antigen (HBsAg) levels to assess the inhibitory effect of the preS2Ab against HBV infection in L02 cells. The inhibitory effect of preS2Ab against hepatic carcinogenesiswas studied with diethylnitrosamine (DEN)-induced hepatocellular carcinomas (HCCs) in HBV transgenic mice. RESULTS: The expression of HBV preS2Ab increased with increases in the multiplicity of infection (MOI) of Ad315-preS2Ab in L02 cells, with 350.87 ± 17.37 μg/L of preS2Ab when the MOI was 100 plaque forming units (pfu)/cell. The expressed preS2Abs could recognize liver cells from HBV transgenic mice. ELISA results showed that L02 cells expressing preS2Ab produced less HBsAg after treatment with the serum of HBV patients than parental L02 cells expressing no preS2Ab. HBV transgenic mice treated with Ad315-preS2Ab had fewer and smaller cancerous nodes after induction with DEN than mice treated with a blank Ad315 vector or untreated mice. Additionally, the administration of Ad315-preS2Ab could alleviate hepatic cirrhosis and decrease the serum levels of alanine transaminase and aspartate transaminase. CONCLUSION: Adenovirus-mediated HBV preS2Ab expression could inhibit HBV infection in L02 cells, and then inhibit DEN-induced hepatocellular carcinogenesis and protect hepatic function in HBV transgenic mice.

  14. Endoplasmic Reticulum-Associated Degradation Factor ERLIN2: Oncogenic Roles and Molecular Targeting of Breast Cancer

    Science.gov (United States)

    2013-06-01

    inflammation. In these interactive signal transduction processes, the functions of the ER and mitochondria are closely linked. These two organelles build...molecular mechanisms by which ERLIN2 coordinates ER pathways in breast carcinogenesis remain unclear. The ER is a cellular organelle primarily...growth-arrested acinar structures with hollow lumens similar to the glandular architecture in vivo, MCF10A- ERLIN2 cells formed abnormal acini at a high

  15. Radiation carcinogenesis and acute radiation mortality in the rat as produced by 2.2 GeV protons

    Science.gov (United States)

    Shellabarger, C. J.; Straub, R. F.; Jesseph, J. E.; Montour, J. L.

    1972-01-01

    Biological studies, proton carcinogenesis, the interaction of protons and gamma-rays on carcinogenesis, proton-induced acute mortality, and chemical protection against proton-induced acute mortality were studied in the rat and these proton-produced responses were compared to similar responses produced by gamma-rays or X-rays. Litter-mate mice were assigned to each experimental and control group so that approximately equal numbers of litter mates were placed in each group. Animals to be studied for mammary neoplasia were handled for 365 days post-exposure when all animals alive were killed. All animals were examined frequently for mammary tumors and as these were found, they were removed, sectioned and given a pathologic classification.

  16. In Situ Nuclear Morphology Measurements Using Light Scattering as Biomarkers of Neoplastic Change in Animal Models of Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Adam Wax

    2008-01-01

    Full Text Available Light scattering spectroscopy measurements can be used to determine the structure of tissue samples. Through refined data acquisition and signal processing techniques, quantitative nuclear morphology measurements may be obtained from light scattering data. These data have been used primarily as a biomarker of neoplastic change in a wide range of settings. Here, we review the application of light scattering to assessing the health status of tissues drawn from animal models of carcinogenesis, in particular, the rat esophagus and the golden Syrian hamster trachea carcinogenesis models. In addition, we present results from ex vivo human tissues to demonstrate the relevance of the use of animal models which are excellent surrogates for several human cancers. These models provide the opportunity to develop biomarkers and test chemopreventive and therapy strategies before application in humans.

  17. Concept Modeling with Superwords

    CERN Document Server

    El-Arini, Khalid; Guestrin, Carlos

    2012-01-01

    In information retrieval, a fundamental goal is to transform a document into concepts that are representative of its content. The term "representative" is in itself challenging to define, and various tasks require different granularities of concepts. In this paper, we aim to model concepts that are sparse over the vocabulary, and that flexibly adapt their content based on other relevant semantic information such as textual structure or associated image features. We explore a Bayesian nonparametric model based on nested beta processes that allows for inferring an unknown number of strictly sparse concepts. The resulting model provides an inherently different representation of concepts than a standard LDA (or HDP) based topic model, and allows for direct incorporation of semantic features. We demonstrate the utility of this representation on multilingual blog data and the Congressional Record.

  18. Bases moleculares de la cancerización de cavidad oral Molecular basis on oral cavity cancerization

    Directory of Open Access Journals (Sweden)

    M.A. González-Moles

    2008-02-01

    Full Text Available Se presenta una revisión bibliográfica breve sobre los principales aspectos moleculares de interés en la cancerización de cavidad oral. Se hace referencia a los conocimientos más recientes sobre las aberraciones cromosómicas más comunes y las alteraciones de los oncogenes y genes supresores tumorales que están implicados en la carcinogénesis oral. Así mismo, se resume la teoría molecular actual que explica el proceso de cancerización de campo.A review about the main molecular aspects on oral cavity cancerization is presented, with special reference to the common chromosomal aberration, oncogenes and tumour suppressor genes implied in oral carcinogenesis. A summary about molecular theory explaining the field cancerization process is also presented.

  19. 52. INHIBITORY EFFECTS OF VITAMIN E SUCCINATE ON BENZO(A) PYRENE-INDUCED FORESTOMACH CARCINOGENESIS IN FEMALE MICE

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@This study is a part of an effort to develop effective chemoprevention for carcinogenesis of the forestomach. Vitamin E succinate(VES) administered by oral gavage and by intraperitioneal (IP) injections was used for the studies. Experimental design involved treating mice with Benzo(a) pyrene and VES(1.25 g/kg and 2.5 g/kg for gavage; 20 mg/kg for IP injections) for 4 weeks in order to study the

  20. Apc-Mutant Kyoto Apc Delta (KAD) Rats Are Susceptible to 4-NQO-Induced Tongue Carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Takuji, E-mail: tmntt08@gmail.com [Department of Diagnostic Pathology (DDP) & Research Center of Diagnostic Pathology (RC-DiP), Gifu Municipal Hospital, 7-1 Kashima-Cho, Gifu 500-8513 (Japan); Department of Tumor Pathology, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194 (Japan); Shimizu, Masahito; Kochi, Takahiro; Shirakami, Yohei [Department of Internal Medicine/Gastroenterology, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194 (Japan); Mori, Takayuki [Department of Pharmacy, Ogaki Municipal Hospital, 4-86 Minaminokawa-cho, Ogaki 503-8502 (Japan); Watanabe, Naoki [Department of Diagnostic Pathology (DDP) & Research Center of Diagnostic Pathology (RC-DiP), Gifu Municipal Hospital, 7-1 Kashima-Cho, Gifu 500-8513 (Japan); Naiki, Takafumi [Department of Clinical Laboratory, Gifu Municipal Hospital, 7-1 Kashima-cho, Gifu 500-8513 (Japan); Moriwaki, Hisataka [Department of Internal Medicine/Gastroenterology, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194 (Japan); Yoshimi, Kazuto; Serikawa, Tadao; Kuramoto, Takashi [The Institute of Laboratory Animals, Graduate School of Medicine, Kyoto University, Yoshidakonoe-cho, Sakyo-ku, Kyoto 606-8501 (Japan)

    2014-07-21

    Despite widening interest in the possible association between infection/inflammation and cancer development, knowledge of this issue in relation to oral cancer remains inadequate. This study aimed to determine the susceptibility of Apc-mutant Kyoto Apc Delta (KAD) rats, which are vulnerable to developing inflammation-associated colorectal carcinogenesis, to 4-nitroquinoline 1-oxide (4-NQO)-induced tongue carcinogenesis in order to clarify the role of inflammation in oral cancer. KAD (20 males and 22 females) and F344/NS1c (22 males and 23 females) rats received drinking water with or without 4-NQO (20 ppm) for eight weeks. Histopathological and immunohistochemical analyses of the tongue were performed at week 20. Additionally, the mRNA expression of inflammatory cytokines in the tongue mucosa was determined at week 8. Tongue squamous cell carcinoma (SCC) developed in the KAD and F344/NS1c rats that received 4-NQO. Regardless of gender, the incidence and multiplicity of tongue SCC were greater in the KAD rats than in the F344/NS1c rats. In addition, the multiplicity of tongue SCC in the female KAD rats was significantly greater than that observed in the male KAD (p < 0.01) and female F344/NS1c rats (p < 0.05). The levels of inflammation and the mRNA expression of inflammatory cytokines in the tongue in the 4-NQO-treated female KAD rats were the highest among the rats given 4-NQO. These results show that KAD rats, particularly females, are susceptible to 4-NQO-induced tongue carcinogenesis, suggesting the utility of models employing KAD rats for investigating the pathobiology of oral (tongue) carcinogenesis associated with inflammation.

  1. Apc-Mutant Kyoto Apc Delta (KAD Rats Are Susceptible to 4-NQO-Induced Tongue Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Takuji Tanaka

    2014-07-01

    Full Text Available Despite widening interest in the possible association between infection/ inflammation and cancer development, knowledge of this issue in relation to oral cancer remains inadequate. This study aimed to determine the susceptibility of Apc-mutant Kyoto Apc Delta (KAD rats, which are vulnerable to developing inflammation-associated colorectal carcinogenesis, to 4-nitroquinoline 1-oxide (4-NQO-induced tongue carcinogenesis in order to clarify the role of inflammation in oral cancer. KAD (20 males and 22 females and F344/NS1c (22 males and 23 females rats received drinking water with or without 4-NQO (20 ppm for eight weeks. Histopathological and immunohistochemical analyses of the tongue were performed at week 20. Additionally, the mRNA expression of inflammatory cytokines in the tongue mucosa was determined at week 8. Tongue squamous cell carcinoma (SCC developed in the KAD and F344/NS1c rats that received 4-NQO. Regardless of gender, the incidence and multiplicity of tongue SCC were greater in the KAD rats than in the F344/NS1c rats. In addition, the multiplicity of tongue SCC in the female KAD rats was significantly greater than that observed in the male KAD (p < 0.01 and female F344/NS1c rats (p < 0.05. The levels of inflammation and the mRNA expression of inflammatory cytokines in the tongue in the 4-NQO-treated female KAD rats were the highest among the rats given 4-NQO. These results show that KAD rats, particularly females, are susceptible to 4-NQO-induced tongue carcinogenesis, suggesting the utility of models employing KAD rats for investigating the pathobiology of oral (tongue carcinogenesis associated with inflammation.

  2. Pueraria mirifica Exerts Estrogenic Effects in the Mammary Gland and Uterus and Promotes Mammary Carcinogenesis in Donryu Rats

    OpenAIRE

    Anna Kakehashi; Midori Yoshida; Yoshiyuki Tago; Naomi Ishii; Takahiro Okuno; Min Gi; Hideki Wanibuchi

    2016-01-01

    Pueraria mirifica (PM), a plant whose dried and powdered tuberous roots are now widely used in rejuvenating preparations to promote youthfulness in both men and women, may have major estrogenic influence. In this study, we investigated modifying effects of PM at various doses on mammary and endometrial carcinogenesis in female Donryu rats. Firstly, PM administered to ovariectomized animals at doses of 0.03%, 0.3%, and 3% in a phytoestrogen-low diet for 2 weeks caused significant increase in u...

  3. Strawberry phytochemicals inhibit azoxymethane/dextran sodium sulfate-induced colorectal carcinogenesis in Crj: CD-1 mice.

    Science.gov (United States)

    Shi, Ni; Clinton, Steven K; Liu, Zhihua; Wang, Yongquan; Riedl, Kenneth M; Schwartz, Steven J; Zhang, Xiaoli; Pan, Zui; Chen, Tong

    2015-03-10

    Human and experimental colon carcinogenesis are enhanced by a pro-inflammatory microenvironment. Pharmacologically driven chemopreventive agents and dietary variables are hypothesized to have future roles in the prevention of colon cancer by targeting these processes. The current study was designed to determine the ability of dietary lyophilized strawberries to inhibit inflammation-promoted colon carcinogenesis in a preclinical animal model. Mice were given a single i.p. injection of azoxymethane (10 mg kg-1 body weight). One week after injection, mice were administered 2% (w/v) dextran sodium sulfate in drinking water for seven days and then an experimental diet containing chemically characterized lyophilized strawberries for the duration of the bioassay. Mice fed control diet, or experimental diet containing 2.5%, 5.0% or 10.0% strawberries displayed tumor incidence of 100%, 64%, 75% and 44%, respectively (p < 0.05). The mechanistic studies demonstrate that strawberries reduced expression of proinflammatory mediators, suppressed nitrosative stress and decreased phosphorylation of phosphatidylinositol 3-kinase, Akt, extracellular signal-regulated kinase and nuclear factor kappa B. In conclusion, strawberries target proinflammatory mediators and oncogenic signaling for the preventive efficacies against colon carcinogenesis in mice. This works supports future development of fully characterized and precisely controlled functional foods for testing in human clinical trials for this disease.

  4. Enhanced levels of glutathione and protein glutathiolation in rat tongue epithelium during 4-NQO-induced carcinogenesis.

    Science.gov (United States)

    Huang, Zhishan; Komninou, Despina; Kleinman, Wayne; Pinto, John T; Gilhooly, Elaine M; Calcagnotto, Ana; Richie, John P

    2007-04-01

    High glutathione (GSH) levels are commonly found in oral tumors and are thought to play an important role in tumorigenesis. While posttranslational binding of GSH to cellular proteins (protein glutathiolation) has recently been recognized as an important redox-sensitive regulatory mechanism, no data currently exist on this process during carcinogenesis. Our goal was to determine the effects of 4-nitroquinoline-N-oxide (4-NQO)-induced carcinogenesis on tongue levels of protein-bound and free GSH and related thiols in the rat. Male F-344 rats (6 weeks of age) were administered either 4-NQO (20 ppm) in drinking water or tap water alone (controls) for 8 weeks. Twenty-four weeks after cessation of 4-NQO, squamous cell carcinomas of the tongue were observed in all rats. The levels of both free and bound GSH in tumors, as well as in adjacent tissues, were 2- to 3-fold greater than in tongue epithelium from control rats (p tongue tissues from control rats (ptongue tissues from 4-NQO treated vs. control rats (p<0.05). Altogether, these results suggest that protein glutathiolation, together with GSH and GSSG levels, are induced during oral carcinogenesis in the rat possibly as a result of enhanced levels of oxidative stress.

  5. Mouse Genetic Models Reveal Surprising Functions of IκB Kinase Alpha in Skin Development and Skin Carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Xiaojun [The Methodist Hospital Research Institute, Houston, TX 77030 (United States); Park, Eunmi [Department of Radiation Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115 (United States); Fischer, Susan M. [Department of Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Smithville, TX 78967 (United States); Hu, Yinling, E-mail: huy2@mail.nih.gov [Cancer and Inflammation Program, Center for Cancer Research, Frederick National Laboratory for Cancer Research, Frederick, MD 21701 (United States)

    2013-02-15

    Gene knockout studies unexpectedly reveal a pivotal role for IκB kinase alpha (IKKα) in mouse embryonic skin development. Skin carcinogenesis experiments show that Ikkα heterozygous mice are highly susceptible to chemical carcinogen or ultraviolet B light (UVB) induced benign and malignant skin tumors in comparison to wild-type mice. IKKα deletion mediated by keratin 5 (K5).Cre or K15.Cre in keratinocytes induces epidermal hyperplasia and spontaneous skin squamous cell carcinomas (SCCs) in Ikkα floxed mice. On the other hand, transgenic mice overexpressing IKKα in the epidermis, under the control of a truncated loricrin promoter or K5 promoter, develop normal skin and show no defects in the formation of the epidermis and other epithelial organs, and the transgenic IKKα represses chemical carcinogen or UVB induced skin carcinogenesis. Moreover, IKKα deletion mediated by a mutation, which generates a stop codon in the Ikkα gene, has been reported in a human autosomal recessive lethal syndrome. Downregulated IKKα and Ikkα mutations and deletions are found in human skin SCCs. The collective evidence not only highlights the importance of IKKα in skin development, maintaining skin homeostasis, and preventing skin carcinogenesis, but also demonstrates that mouse models are extremely valuable tools for revealing the mechanisms underlying these biological events, leading our studies from bench side to bedside.

  6. Inhibitory effects of polysaccharides isolated from Phellinus gilvus on benzo(a)pyrene-induced forestomach carcinogenesis in mice

    Institute of Scientific and Technical Information of China (English)

    Jae-Sung Bae; Kwang-Ho Jang; Hyunee Yim; Seung-Chun Park; Hee-Kyung Jin

    2005-01-01

    AIM: Although polysaccharides from Phellinus mushrooms are a well-known material with anti-tumor properties, there is no information about the effect of polysaccharides from Phellinus gilvus (PG) on tumor. The modulating effect of polysaccharides isolated from PG on the benzo(a)pyrene (BaP)-induced forestomach carcinogenesis in ICR female mice was investigated in this study.METHODS: A forestomach carcinogenesis model was established in 40 ICR female mice receiving oral administration of BaP for 4 wk. The mice were randomly assigned to 4 groups (10 each). The mice in each group were treated with sterile water or PG for 4 and 8 wk (SW4,PGW4, SW8, and PGW8 groups). Eight or 12 wk after the first dose of BaP, forestomachs were removed for histopathological and RT-PCR analysis.RESULTS: In histopathological changes and RT-PCR analysis, sterile water-treated mice showed significant hyperplasia of the gastric mucosa with a significantly increased expression of mutant p53 mRNA compared to mice treated with PG for 8 wk.CONCLUSION: Polysaccharides isolated from PG may inhibit BaP-induced forestomach carcinogenesis in mice bydown-regulating mutant p53 expression.

  7. Strawberry Phytochemicals Inhibit Azoxymethane/Dextran Sodium Sulfate-Induced Colorectal Carcinogenesis in Crj: CD-1 Mice

    Directory of Open Access Journals (Sweden)

    Ni Shi

    2015-03-01

    Full Text Available Human and experimental colon carcinogenesis are enhanced by a pro-inflammatory microenvironment. Pharmacologically driven chemopreventive agents and dietary variables are hypothesized to have future roles in the prevention of colon cancer by targeting these processes. The current study was designed to determine the ability of dietary lyophilized strawberries to inhibit inflammation-promoted colon carcinogenesis in a preclinical animal model. Mice were given a single i.p. injection of azoxymethane (10 mg kg−1 body weight. One week after injection, mice were administered 2% (w/v dextran sodium sulfate in drinking water for seven days and then an experimental diet containing chemically characterized lyophilized strawberries for the duration of the bioassay. Mice fed control diet, or experimental diet containing 2.5%, 5.0% or 10.0% strawberries displayed tumor incidence of 100%, 64%, 75% and 44%, respectively (p < 0.05. The mechanistic studies demonstrate that strawberries reduced expression of proinflammatory mediators, suppressed nitrosative stress and decreased phosphorylation of phosphatidylinositol 3-kinase, Akt, extracellular signal-regulated kinase and nuclear factor kappa B. In conclusion, strawberries target proinflammatory mediators and oncogenic signaling for the preventive efficacies against colon carcinogenesis in mice. This works supports future development of fully characterized and precisely controlled functional foods for testing in human clinical trials for this disease.

  8. Molecular Population Genetics

    Science.gov (United States)

    Casillas, Sònia; Barbadilla, Antonio

    2017-01-01

    Molecular population genetics aims to explain genetic variation and molecular evolution from population genetics principles. The field was born 50 years ago with the first measures of genetic variation in allozyme loci, continued with the nucleotide sequencing era, and is currently in the era of population genomics. During this period, molecular population genetics has been revolutionized by progress in data acquisition and theoretical developments. The conceptual elegance of the neutral theory of molecular evolution or the footprint carved by natural selection on the patterns of genetic variation are two examples of the vast number of inspiring findings of population genetics research. Since the inception of the field, Drosophila has been the prominent model species: molecular variation in populations was first described in Drosophila and most of the population genetics hypotheses were tested in Drosophila species. In this review, we describe the main concepts, methods, and landmarks of molecular population genetics, using the Drosophila model as a reference. We describe the different genetic data sets made available by advances in molecular technologies, and the theoretical developments fostered by these data. Finally, we review the results and new insights provided by the population genomics approach, and conclude by enumerating challenges and new lines of inquiry posed by increasingly large population scale sequence data. PMID:28270526

  9. Role of nitric oxide in the pathogenesis ofBarrett's-associated carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    Barrett's esophagus (BE), a premalignant condition toBarrett's adenocarcinoma (BAC), is closely associatedwith chronic inflammation due to gastro-esophagealreflux. Caudal type homeobox 2 (CDX2), a representativemarker of BE, is increased during the metaplasticand neoplastic transformation of BE. Nitric oxide (NO)has been proposed to be a crucial mediator of Barrett'scarcinogenesis. We previously demonstrated that CDX2 might be induced directly under stimulation oflarge amounts of NO generated around the gastroesophagealjunction (GEJ) by activating epithelial growthfactor receptor in a ligand-independent manner. Thus,we reviewed recent developments on the role of NOin Barrett's carcinogenesis. Notably, recent studieshave reported that microbial communities in the distalesophagus are significantly different among groupswith a normal esophagus, reflux esophagitis, BE orBAC, despite there being no difference in the bacterialquantity. Considering that microorganism componentscan be one of the major sources of large amounts ofNO, these studies suggest that the bacterial compositionin the distal esophagus might play an important rolein regulating NO production during the carcinogenicprocess. Controlling an inflammatory reaction due togastro-esophageal reflux or bacterial composition aroundthe GEJ might help prevent the progression of Barrett'scarcinogenesis by inhibiting NO production.

  10. Introduction and overview. Perinatal carcinogenesis: growing a node for epidemiology, risk management, and animal studies.

    Science.gov (United States)

    Anderson, Lucy M

    2004-09-01

    Perinatal carcinogenesis as a cross-disciplinary concern is the subject of this special issue of Toxicology and Applied Pharmacology, which consists of a total of eight reviews or commentaries in the areas of epidemiology, risk assessment, and animal models. Some of the conclusions from these articles, and the Questions and Answers section that follows most of them, are summarized here. There is adequate reason to suspect that perinatal exposures contribute to human cancer risk, both childhood cancers, and those appearing later in life. The latter type of risk may actually be quantitatively the more important, and involve a wide range of types of effects, but has received only limited attention. With regard to childhood cancers, fetal irradiation and diethylstilbestrol exposure are known etiological agents, and it is likely, but not yet certain, there are additional external causes of a portion of these. Some current focal points of interest here include nitroso compounds, DNA topoisomerase inhibitors, viruses, anti-AIDS drugs, and endocrine disruptors. Regulatory agencies must rely heavily on animal data for estimation of human risk due to perinatal exposures to chemicals, and the quantity and quality of these data presently available for this purpose are greatly limiting. Correctly designed conventional animal studies with suspect chemicals are still needed. Furthermore, genetically engineered mouse models for childhood cancers, especially medulloblastoma, have become available, and could be used for screening of candidate causative agents for this cancer type, and for better understanding of gene-environment interactions.

  11. Atomic Bomb Survivors Life-Span Study: Insufficient Statistical Power to Select Radiation Carcinogenesis Model.

    Science.gov (United States)

    Socol, Yehoshua; Dobrzyński, Ludwik

    2015-01-01

    The atomic bomb survivors life-span study (LSS) is often claimed to support the linear no-threshold hypothesis (LNTH) of radiation carcinogenesis. This paper shows that this claim is baseless. The LSS data are equally or better described by an s-shaped dependence on radiation exposure with a threshold of about 0.3 Sievert (Sv) and saturation level at about 1.5 Sv. A Monte-Carlo simulation of possible LSS outcomes demonstrates that, given the weak statistical power, LSS cannot provide support for LNTH. Even if the LNTH is used at low dose and dose rates, its estimation of excess cancer mortality should be communicated as 2.5% per Sv, i.e., an increase of cancer mortality from about 20% spontaneous mortality to about 22.5% per Sv, which is about half of the usually cited value. The impact of the "neutron discrepancy problem" - the apparent difference between the calculated and measured values of neutron flux in Hiroshima - was studied and found to be marginal. Major revision of the radiation risk assessment paradigm is required.

  12. The Potential Protective Effects of Polyphenols in Asbestos-Mediated Inflammation and Carcinogenesis of Mesothelium

    Directory of Open Access Journals (Sweden)

    Monica Benvenuto

    2016-05-01

    Full Text Available Malignant Mesothelioma (MM is a tumor of the serous membranes linked to exposure to asbestos. A chronic inflammatory response orchestrated by mesothelial cells contributes to the development and progression of MM. The evidence that: (a multiple signaling pathways are aberrantly activated in MM cells; (b asbestos mediated-chronic inflammation has a key role in MM carcinogenesis; (c the deregulation of the immune system might favor the development of MM; and (d a drug might have a better efficacy when injected into a serous cavity thus bypassing biotransformation and reaching an effective dose has prompted investigations to evaluate the effects of polyphenols for the therapy and prevention of MM. Dietary polyphenols are able to inhibit cancer cell growth by targeting multiple signaling pathways, reducing inflammation, and modulating immune response. The ability of polyphenols to modulate the production of pro-inflammatory molecules by targeting signaling pathways or ROS might represent a key mechanism to prevent and/or to contrast the development of MM. In this review, we will report the current knowledge on the ability of polyphenols to modulate the immune system and production of mediators of inflammation, thus revealing an important tool in preventing and/or counteracting the growth of MM.

  13. The Potential Protective Effects of Polyphenols in Asbestos-Mediated Inflammation and Carcinogenesis of Mesothelium.

    Science.gov (United States)

    Benvenuto, Monica; Mattera, Rosanna; Taffera, Gloria; Giganti, Maria Gabriella; Lido, Paolo; Masuelli, Laura; Modesti, Andrea; Bei, Roberto

    2016-05-09

    Malignant Mesothelioma (MM) is a tumor of the serous membranes linked to exposure to asbestos. A chronic inflammatory response orchestrated by mesothelial cells contributes to the development and progression of MM. The evidence that: (a) multiple signaling pathways are aberrantly activated in MM cells; (b) asbestos mediated-chronic inflammation has a key role in MM carcinogenesis; (c) the deregulation of the immune system might favor the development of MM; and (d) a drug might have a better efficacy when injected into a serous cavity thus bypassing biotransformation and reaching an effective dose has prompted investigations to evaluate the effects of polyphenols for the therapy and prevention of MM. Dietary polyphenols are able to inhibit cancer cell growth by targeting multiple signaling pathways, reducing inflammation, and modulating immune response. The ability of polyphenols to modulate the production of pro-inflammatory molecules by targeting signaling pathways or ROS might represent a key mechanism to prevent and/or to contrast the development of MM. In this review, we will report the current knowledge on the ability of polyphenols to modulate the immune system and production of mediators of inflammation, thus revealing an important tool in preventing and/or counteracting the growth of MM.

  14. Differential protective effects of red wine polyphenol extracts (RWEs) on colon carcinogenesis.

    Science.gov (United States)

    Mazué, Frédéric; Delmas, Dominique; Murillo, Genoveva; Saleiro, Diana; Limagne, Emeric; Latruffe, Norbert

    2014-04-01

    Various epidemiological studies have shown that a regular and moderate consumption of red wine is correlated with a decreased relative risk of developing coronary heart disease and cancer. These health benefits are commonly attributed to high contents of polyphenols, particularly resveratrol, representing important sources of antioxidants. However, resveratrol does not seem to be the only bioactive compound present in the wine which contains numerous other polyphenols. The present study investigates the efficiency of red wine extracts (RWEs), containing different polyphenols, on colon cancer cell proliferation in vitro and on colonic aberrant crypt foci (ACF) in vivo. Proliferation, cell cycle analysis and incidence of ACF were monitored to examine the effects of RWEs. RWEs derived from a long vinification process exhibit superior anti-proliferative activity in colon cancer cells and prevent the appearance of ACF in mice. Interestingly, quercetin and resveratrol, representing two major bio-active polyphenols, exhibit synergistic anti-proliferative effects. These data suggest that the efficacy of RWEs on colon carcinogenesis may depend on the polyphenolic content, synergistic interaction of bio-active polyphenols and modulation of cellular uptake of polyphenols.

  15. Role of environmental chemicals, processed food derivatives, and nutrients in the induction of carcinogenesis.

    Science.gov (United States)

    Persano, Luca; Zagoura, Dimitra; Louisse, Jochem; Pistollato, Francesca

    2015-10-15

    In recent years it has been hypothesized that cancer stem cells (CSCs) are the actual driving force of tumor formation, highlighting the need to specifically target CSCs to successfully eradicate cancer growth and recurrence. Particularly, the deregulation of physiological signaling pathways controlling stem cell proliferation, self-renewal, differentiation, and metabolism is currently considered as one of the leading determinants of cancer formation. Given their peculiar, slow-dividing phenotype and their ability to respond to multiple microenvironmental stimuli, stem cells appear to be more susceptible to genetic and epigenetic carcinogens, possibly undergoing mutations resulting in tumor formation. In particular, some animal-derived bioactive nutrients and metabolites known to affect the hormonal milieu, and also chemicals derived from food processing and cooking, have been described as possible carcinogenic factors. Here, we review most recent literature in this field, highlighting how some environmental toxicants, some specific nutrients and their secondary products can induce carcinogenesis, possibly impacting stem cells and their niches, thus causing tumor growth.

  16. Correlation of neomycin, faecal neutral and acid sterols with colon carcinogenesis in rats.

    Science.gov (United States)

    Panda, S K; Chattoraj, S C; Broitman, S A

    1999-06-01

    High fat diets have been implicated in incidence of colon cancer both in epidemiological and animal studies. Present investigation deals with the incidence, location and numbers of large and small bowel tumours induced by 1,2-dimethyl hydrazine (DMH) in rats fed high fat diets and neomycin. Neomycin was used to modify the faecal sterol metabolism and the relationship of the high fat diet and faecal neutral and acid sterols to the large bowel tumorigenesis was evaluated. DMH administered rats were fed with (a) 20% safflower oil; (b) 20% safflower oil and neomycin; (c) 20% safflower oil, cholesterol and cholic acid; and (d) 20% safflower oil, cholesterol, cholic acid and neomycin. Neomycin was found to be associated with both increase and decrease of tumour numbers. The faecal sterols lithocholic and deoxycholic acids were found to have no participation, while cholesterol and cholic acid were found to decrease with increase in tumour numbers. However, faecal coprostanol has been found to have a significant positive correlation with tumorigenesis in all dietary groups. Therefore coprostanol might possibly be associated with colon carcinogenesis in DMH-fed rats and cholesterol metabolism in gut appears to be related to the development of tumours.

  17. Pioglitazone, a Peroxisome Proliferator-Activated Receptor γ Agonist, Suppresses Rat Prostate Carcinogenesis

    Science.gov (United States)

    Suzuki, Shugo; Mori, Yukiko; Nagano, Aya; Naiki-Ito, Aya; Kato, Hiroyuki; Nagayasu, Yuko; Kobayashi, Mizuho; Kuno, Toshiya; Takahashi, Satoru

    2016-01-01

    Pioglitazone (PGZ), a peroxisome proliferator-activated receptor γ agonist, which is known as a type 2 diabetes drug, inhibits cell proliferation in various cancer cell lines, including prostate carcinomas. This study focused on the effect of PGZ on prostate carcinogenesis using a transgenic rat for an adenocarcinoma of prostate (TRAP) model. Adenocarcinoma lesions as a percentage of overall lesions in the ventral prostate were significantly reduced by PGZ treatment in a dose-dependent manner. The number of adenocarcinomas per given area in the ventral prostate was also significantly reduced by PGZ treatment. The Ki67 labeling index in the ventral prostate was also significantly reduced by PGZ. Decreased cyclin D1 expression in addition to the inactivation of both p38 mitogen-activated protein kinase (MAPK) and nuclear factor (NF)κB were detected in PGZ-treated TRAP rat groups. In LNCaP, a human androgen-dependent prostate cancer cell line, PGZ also inhibited cyclin D1 expression and the activation of both p38 MAPK and NFκB. The suppression of cultured cell growth was mainly regulated by the NFκB pathway as detected using specific inhibitors in both LNCaP and PC3, a human androgen-independent prostate cancer cell line. These data suggest that PGZ possesses a chemopreventive potential for prostate cancer. PMID:27973395

  18. Myenteric denervation in gastric carcinogenesis: differential modulation of nitric oxide and annexin-A1.

    Science.gov (United States)

    Polli-Lopes, Ana Cláudia; Estofolete, Cássia F; Oliani, Sonia M; Zucoloto, Sérgio; Cunha, Fernando Q; Gil, Cristiane D

    2013-01-01

    This study evaluated the properties of endogenous nitric oxide synthases (NOS) and annexin-A1 (ANXA1) and determined how they can be exploited in the N-methyl-N-nitro-N-nitrosoguanidine (MNNG)-induced gastric carcinogenesis and myenteric denervation model. Male Wistar rats were treated with MNNG and/or aminoguanidine (AG) for 20 weeks. In another set of experiments, rats with nondenervated and denervated stomachs were treated with MNNG or water for 28 weeks. Fragments of the pyloric region were processed for histopathology, NOS activity, and immunohistochemistry to explore the activity and expression of constitutive (cNOS) and inducible (iNOS) NO synthase and their relationship with annexin-A1 (ANXA1) expression. NO inhibition by AG increased the percentage of animals with adenocarcinomas (~29%) compared with the untreated MNNG group (~4%). Myenteric denervation did not alter NOS activity. cNOS activity was significantly greater in nondernervated and denervated stomachs with or without lesions (Pactivity (Pactivity in normal stomachs and outside the lesion area was considerably higher than inside it (Pmyenteric denervation. In conclusion, NO protects against the development of gastric adenocarcinomas. The pattern of ANXA1 expression was not associated with NOS activity or expression, suggesting that NO and ANXA1 act in gastric tumors in disparate pathways.

  19. Role of copper accumulation in spontaneous renal carcinogenesis in Long-Evans Cinnamon rats.

    Science.gov (United States)

    Kitaura, K; Chone, Y; Satake, N; Akagi, A; Ohnishi, T; Suzuki, Y; Izumi, K

    1999-04-01

    Spontaneous renal cell tumors in totals of 223 male and female Long-Evans Cinnamon (LEC) rats of 51-120 weeks old, 157 male F344 rats of 51-120 weeks old, and 14 male Long-Evans Agouti (LEA) rats of 51-70 weeks old were examined histologically. The incidences of renal cell tumors increased with age in male and female LEC rats, but no tumors developed in F344 or LEA rats. Dilated atypical tubules of the kidneys were observed at high incidence in aged LEC rats. Copper staining of LEC rat kidneys showed a positive reaction in proximal tubules of the cortex and the outer stripe of the medulla. The renal copper concentration of LEC rats reached a peak in the period of necrotizing hepatitis with renal tubular necrosis, and was higher than that in F344 rats for up to 106 weeks. In contrast, the renal iron concentration of LEC rats was lower than that in F344 rats except in the period of necrotizing hepatitis. Long-term treatment of LEC rats with D-penicillamine, a copper-chelating agent, inhibited accumulation of copper, but not iron, in the kidneys, and inhibited the development of karyomegaly of proximal tubules and dilated atypical tubules. These results suggest that persistent copper accumulation after toxic necrosis of tubules is the major cause of spontaneous renal carcinogenesis in LEC rats.

  20. Utility of MicroRNAs and siRNAs in Cervical Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Sacnite del Mar Díaz-González

    2015-01-01

    Full Text Available MicroRNAs and siRNAs belong to a family of small noncoding RNAs which bind through partial sequence complementarity to 3′-UTR regions of mRNA from target genes, resulting in the regulation of gene expression. MicroRNAs have become an attractive target for genetic and pharmacological modulation due to the critical function of their target proteins in several signaling pathways, and their expression profiles have been found to be altered in various cancers. A promising technology platform for selective silencing of cell and/or viral gene expression using siRNAs is currently in development. Cervical cancer is the most common cancer in women in the developing world and sexually transmitted infection with HPV is the cause of this malignancy. Therefore, a cascade of abnormal events is induced during cervical carcinogenesis, including the induction of genomic instability, reprogramming of cellular metabolic pathways, deregulation of cell proliferation, inhibition of apoptotic mechanisms, disruption of cell cycle control mechanisms, and alteration of gene expression. Thus, in the present review article, we highlight new research on microRNA expression profiles which may be utilized as biomarkers for cervical cancer. Furthermore, we discuss selective silencing of HPV E6 and E7 with siRNAs which represents a potential gene therapy strategy against cervical cancer.

  1. Critical pathogenic steps to high risk Helicobacter pylori gastritis and gastric carcinogenesis.

    Science.gov (United States)

    Lee, Inchul

    2014-06-07

    Helicobacter pylori (H. pylori) gastritis may progress to high risk gastropathy and cancer. However, the pathological progression has not been characterized in detail. H. pylori induce persistent inflammatory infiltration. Neutrophils are unique in that they directly infiltrate into foveolar epithelium aiming the proliferative zone specifically. Neutrophilic proliferative zone foveolitis is a critical pathogenic step in H. pylori gastritis inducing intensive epithelial damage. Epithelial cells carrying accumulated genomic damage and mutations show the Malgun (clear) cell change, characterized by large clear nucleus and prominent nucleolus. Malgun cells further undergo atypical changes, showing nuclear folding, coarse chromatin, and multiple nucleoli. The atypical Malgun cell (AMC) change is a novel premalignant condition in high risk gastropathy, which may progress and undergo malignant transformation directly. The pathobiological significance of AMC in gastric carcinogenesis is reviewed. A new diagnosis system of gastritis is proposed based on the critical pathologic steps classifying low and high risk gastritis for separate treatment modality. It is suggested that the regulation of H. pylori-induced neutrophilic foveolitis might be a future therapeutic goal replacing bactericidal antibiotics approach.

  2. Genetic characteristics of mitochondrial DNA was associated with colorectal carcinogenesis and its prognosis.

    Directory of Open Access Journals (Sweden)

    Jae-Ho Lee

    Full Text Available Clinical value of mitochondrial DNA has been described in colorectal cancer (CRC. To clarify its role in colorectal carcinogenesis, mitochondrial microsatellite instability (mtMSI and other markers were investigated in CRCs and their precancerous lesions, as a multitier genetic study. DNA was isolated from paired normal and tumoral tissues in 78 tubular adenomas (TAs, 34 serrated polyps (SPs, and 100 CRCs. mtMSI, nucleus microsatellite instability (nMSI, KRAS mutation, and BRAF mutation were investigated in these tumors and their statistical analysis was performed. mtMSI was found in 30% of CRCs and 21.4% of precancerous lesions. Mitochondrial copy number was higher in SPs than TAs and it was associated with mtMSI in low grade TAs. KRAS and BRAF mutations were mutually exclusive in TAs and SPs. CRCs with mtMSI showed shorter overall survival times than the patients without mtMSI. In CRCs without nMSI or BRAF mutation, mtMSI was a more accurate marker for predicting prognosis. The genetic change of mitochondrial DNA is an early and independent event in colorectal precancerous lesions and mtMSI and mitochondrial contents are associated with the tubular adenoma-carcinoma sequence, resulting in poor prognosis. This result suggested that the genetic change in mitochondrial DNA appears to be a possible prognosis marker in CRC.

  3. Folate levels in mucosal tissue but not methylenetetrahydrofolate reductase polymorphisms are associated with gastric carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    Yu-Rong Weng; Dan-Feng Sun; Jing-Yuan Fang; Wei-Qi Gu; Hong-Yin Zhu

    2006-01-01

    AIM: To evaluate whether folate levels in mucosal tissue and some common methylenetetrahydrofolate reductase (MTHFR) variants are associated with the risk of gastric cancer through DNA methylation.METHODS: Real-time PCR was used to study the expression of tumor related genes in 76 mucosal tissue samples from 38 patients with gastric cancer. Samples from the gastroscopic biopsy tissues of 34 patients with chronic superficial gastritis (CSG) were used as controls.Folate concentrations in these tissues were detected by the FOL ACS: 180 automated chemiluminescence system.MTHFR polymorphisms were analyzed by PCR-RFLP, and the promoter methylation of tumor-related genes was determined by methylation-specific PCR (MSP).RESULTS: Folate concentrations were significantly higher in CSG than in cancerous tissues. Decreased expression and methylation of c-myc accompanied higher folate concentrations. Promoter hypermethylation and loss of p16INK4A in samples with MTHFR 677CC were more frequent than in samples with the 677TT or 677CT genotype. And the promoter hypermethylation and loss of p21WAF1 in samples with MTHFR 677CT were more frequent than when 677CC or 677TT was present. The 677CT genotype showed a non-significant higher risk for gastric cancer as compared with the 677CC genotype.CONCLUSION: Lower folate levels in gastric mucosal tissue may confer a higher risk of gastric carcinogenesis through hypomethylation and overexpression of c-myc.

  4. Utility of MicroRNAs and siRNAs in Cervical Carcinogenesis

    Science.gov (United States)

    Díaz-González, Sacnite del Mar; Benítez-Boijseauneau, Odelia; Gómez-Cerón, Claudia; Bermúdez-Morales, Victor Hugo; Rodríguez-Dorantes, Mauricio; Pérez-Plasencia, Carlos; Peralta-Zaragoza, Oscar

    2015-01-01

    MicroRNAs and siRNAs belong to a family of small noncoding RNAs which bind through partial sequence complementarity to 3′-UTR regions of mRNA from target genes, resulting in the regulation of gene expression. MicroRNAs have become an attractive target for genetic and pharmacological modulation due to the critical function of their target proteins in several signaling pathways, and their expression profiles have been found to be altered in various cancers. A promising technology platform for selective silencing of cell and/or viral gene expression using siRNAs is currently in development. Cervical cancer is the most common cancer in women in the developing world and sexually transmitted infection with HPV is the cause of this malignancy. Therefore, a cascade of abnormal events is induced during cervical carcinogenesis, including the induction of genomic instability, reprogramming of cellular metabolic pathways, deregulation of cell proliferation, inhibition of apoptotic mechanisms, disruption of cell cycle control mechanisms, and alteration of gene expression. Thus, in the present review article, we highlight new research on microRNA expression profiles which may be utilized as biomarkers for cervical cancer. Furthermore, we discuss selective silencing of HPV E6 and E7 with siRNAs which represents a potential gene therapy strategy against cervical cancer. PMID:25874209

  5. Alterations in Gastric Microbiota After H. Pylori Eradication and in Different Histological Stages of Gastric Carcinogenesis

    Science.gov (United States)

    Li, Tung Hiu; Qin, Youwen; Sham, Pak Chung; Lau, K.S.; Chu, Kent-Man; Leung, Wai K.

    2017-01-01

    The role of bacteria other than Helicobacter pylori (HP) in the stomach remains elusive. We characterized the gastric microbiota in individuals with different histological stages of gastric carcinogenesis and after receiving HP eradication therapy. Endoscopic gastric biopsies were obtained from subjects with HP gastritis, gastric intestinal metaplasia (IM), gastric cancer (GC) and HP negative controls. Gastric microbiota was characterized by Illumina MiSeq platform targeting the 16 S rDNA. Apart from dominant H. pylori, we observed other Proteobacteria including Haemophilus, Serratia, Neisseria and Stenotrophomonas as the major components of the human gastric microbiota. Although samples were largely converged according to the relative abundance of HP, a clear separation of GC and other samples was recovered. Whilst there was a strong inverse association between HP relative abundance and bacterial diversity, this association was weak in GC samples which tended to have lower bacterial diversity compared with other samples with similar HP levels. Eradication of HP resulted in an increase in bacterial diversity and restoration of the relative abundance of other bacteria to levels similar to individuals without HP. In conclusion, HP colonization results in alterations of gastric microbiota and reduction in bacterial diversity, which could be restored by antibiotic treatment. PMID:28322295

  6. Carcinogenesis, prevention and early detection of gastric cancer: where we are and where we should go.

    Science.gov (United States)

    González, Carlos A; Agudo, Antonio

    2012-02-15

    Helicobacter pylori is the most common cause of gastric cancer (GC), though smoking, alcohol, diet, genetics and epigenetic factors may also have a role in the occurrence of the disease. Why H. pylori cause GC in only a minority of those infected remains unknown. Although mechanisms of H. pylori-induced carcinogenesis are not yet well understood, several genotypes of H. pylori have been associated with strain virulence and disease risk. Primary prevention of GC should be addressed by avoiding exposure to factors that increase the risk and to promote factors associated with decrease risk. Vaccines against H. pylori are an ongoing promise and not yet available. Chemoprevention through vitamin supplementation has shown no benefit. Screening and eradication of H. pylori in the general population is not advised. Given that GC is a multiple-steps process, the identification of patients with preneoplastic lesions with high risk of progression, and periodic endoscopic surveillance of them represents the most effective way for early diagnosis of GC. However, clinical guidelines for surveillance are lacking and there are no clear criteria to classify patients into high or low risk of progressing to GC. No study has shown the potential usefulness of combining the information on the type of preneoplastic lesions, genetic and epigenetic, lifestyle and virulence bacterial factors in order to identify high risk patients who need more intensive surveillance. The integration of all this information, in a prediction model requires further research and could be the most important contribution for reducing the burden of GC.

  7. The significance of azo-reduction in the mutagenesis and carcinogenesis of azo dyes.

    Science.gov (United States)

    Chung, K T

    1983-04-01

    Azo dyes are widely used in textile, printing, cosmetic, drug and food-processing industries. They are also used extensively in laboratories as either biological stains or pH indicators. The extent of such use is related to the degree of industrialization. Since intestinal cancer is more common in highly industrialized countries, a possible connection may exist between the increase in the number of cancer cases and the use of azo dyes. Azo dyes can be reduced to aromatic amines by the intestinal microflora. The mutagenicity of a number of azo dyes is reviewed in this paper. They include Trypan Blue, Ponceau 3R, Pinceau 2R, Methyl Red, Methyl Yellow, Methyl Orange, Lithol Red, Orange I, Orange II, 4-Phenylazo-Naphthylamine, Sudan I, Sudan IV, Acid Alizarin Violet N, Fast Garnet GBC, Allura Red, Ponceau SX, Sunset Yellow, Tartrazine, Citrus Red No. 2, Orange B, Yellow AB, Carmoisine, Mercury Orange, Ponceau S, Versatint Blue, Phenylazophenol, Evan's Blue and their degraded aromatic amines. The significance of azo reduction in the mutagenesis and carcinogenesis of azo dyes is discussed.

  8. Evolution of Tumor Metabolism might Reflect Carcinogenesis as a Reverse Evolution process (Dismantling of Multicellularity

    Directory of Open Access Journals (Sweden)

    Adil H.H. Bashir

    2011-07-01

    Full Text Available Carcinogenesis occurs through a series of steps from normal into benign and finally malignant phenotype. This cancer evolutionary trajectory has been accompanied by similar metabolic transformation from normal metabolism into Pasteur and/or Crabtree-Effects into Warburg-Effect and finally Cannibalism and/or Lactate-Symbiosis. Due to lactate production as an end-product of glycolysis, tumor colonies acquire new phenotypes that rely on lactate as energetic fuel. Presence of Warburg-Effect indicates that some tumor cells undergo partial (if not complete de-endosymbiosis and so cancer cells have been become unicellular microorganism (anti-Dollo’s Law specially when they evolve to develop cannibalism as way of metabolism while oxidative types of cells that rely on lactate, as their energetic fuel, might represent extra-endosymbiosis. Thus, at the end, the cancer colony could be considered as integrated metabolic ecosystem. Proper understanding of tumor metabolism will contribute to discover potential anticancer agents besides conventional chemotherapy.

  9. Evolution of Tumor Metabolism might Reflect Carcinogenesis as a Reverse Evolution process (Dismantling of Multicellularity)

    Energy Technology Data Exchange (ETDEWEB)

    Alfarouk, Khalid O., E-mail: Alfarouk@Hala-alfarouk.org [Department of Evolution of Tumor Metabolism and Pharmacology, Hala Alfarouk Cancer Center, Khartoum 11123 (Sudan); Shayoub, Mohammed E.A. [Department of Pharmaceutics, Faculty of Pharmacy, University of Khartoum, Khartoum 11111 (Sudan); Muddathir, Abdel Khalig [Department of Pharmacognosy, Faculty of Pharmacy, University of Khartoum, Khartoum 11111 (Sudan); Elhassan, Gamal O. [General Directorate of Pharmacy, Federal Ministry of Health, Khartoum 11111 (Sudan); Bashir, Adil H.H. [Department of Evolution of Tumor Metabolism and Pharmacology, Hala Alfarouk Cancer Center, Khartoum 11123 (Sudan); Al Jawda Medical Hospital, Khartoum 11111 (Sudan)

    2011-07-22

    Carcinogenesis occurs through a series of steps from normal into benign and finally malignant phenotype. This cancer evolutionary trajectory has been accompanied by similar metabolic transformation from normal metabolism into Pasteur and/or Crabtree-Effects into Warburg-Effect and finally Cannibalism and/or Lactate-Symbiosis. Due to lactate production as an end-product of glycolysis, tumor colonies acquire new phenotypes that rely on lactate as energetic fuel. Presence of Warburg-Effect indicates that some tumor cells undergo partial (if not complete) de-endosymbiosis and so cancer cells have been become unicellular microorganism (anti-Dollo's Law) specially when they evolve to develop cannibalism as way of metabolism while oxidative types of cells that rely on lactate, as their energetic fuel, might represent extra-endosymbiosis. Thus, at the end, the cancer colony could be considered as integrated metabolic ecosystem. Proper understanding of tumor metabolism will contribute to discover potential anticancer agents besides conventional chemotherapy.

  10. Immunological and Biochemical Markers in Oral Carcinogenesis: The Public Health Perspective

    Directory of Open Access Journals (Sweden)

    Sunali Khanna

    2008-12-01

    Full Text Available Oral health is an integral component of general health and well being and a basic human right. Dental public health is probably the most challenging specialty of dentistry. Because of the lack of adequate resources among other factors, many people are likely to suffer from dental diseases. Despite great improvements in the oral health status of populations across the world, the burden and impact of dental diseases are still high. This is particularly true among underprivileged groups in both developed and developing communities. Oral diseases and conditions, including oral cancer, oral manifestations of HIV/AIDS, dental trauma, craniofacial anomalies, and noma, all have broad impacts on health and well-being. Oral cancer, the sixth most common cancer worldwide continues to be most prevalent cancer related to the consumption of tobacco, alcohol and other carcinogenic products. Nevertheless, significant reduction in mortality can be achieved by advances in early diagnosis and implementation of multidisciplinary treatment programs leading to improvement of survivorship and better quality of life. The present study was designed to evaluate the immunologic and biochemical markers in oral carcinogenesis using circulating immune complexes (CIC, copper, iron, and selenium concentrations as assessment endpoints. Study results indicated an increase in CIC and copper levels, and a decrease in iron and selenium concentrations in oral cancer patients compared to controls. The implications of these findings for public health are discussed.

  11. Metabolism of phenylhydroquinone by prostaglandin (H) synthase: possible implications in o-phenylphenol carcinogenesis.

    Science.gov (United States)

    Kolachana, P; Subrahmanyam, V V; Eastmond, D A; Smith, M T

    1991-01-01

    o-Phenylphenol (OPP) and its sodium salt sodium ortho-phenylphenate (NaOPP) are broad spectrum fungicides and antibacterial agents. Both are urinary bladder and renal carcinogens in the Fischer 344 rat. OPP is converted by mixed-function oxidases in the liver to phenylhydroquinone (PHQ). Since appreciable amounts of prostaglandin (H) synthase (PGS) are found in rat bladder and kidney-medullary papilla, the target sites of OPP- and NaOPP-induced tumors, we hypothesized that a secondary PGS-mediated activation of PHQ to phenylbenzoquinone (PBQ) may occur in the bladder and kidney. We have studied the metabolism of PHQ by PGS in the presence of arachidonic acid and hydrogen peroxide as co-factors. These studies showed that PHQ is indeed metabolized to a product having identical spectral and electrochemical properties to PBQ. The disappearance of PHQ with time was stoichiometric to the formation of PBQ. Less than 10% of PHQ was converted to PBQ in the absence of enzyme, indicating that auto-oxidation may play only a minor role in the conversion of PHQ to PBQ. Similar results were obtained when PGS was replaced with either myeloperoxidase or horseradish peroxidase and hydrogen peroxide as co-factor. These studies suggest that the peroxidative metabolism of PHQ by PGS to the reactive PBQ could play an important role in OPP-induced urinary bladder and kidney carcinogenesis in rats.

  12. The effect of childbirth on carcinogenesis of DMBA-induced breast cancer in female SD rats.

    Science.gov (United States)

    Zhao, Ji-An; Chen, Jin-Jun; Ju, Ying-Chao; Wu, Jian-Hua; Geng, Cui-Zhi; Yang, Hui-Chai

    2011-11-01

    Many epidemiologic and clinical studies have indicated that the frequency of breast cancer was lower in parous women than in nulliparous women. Moreover, the incidence of breast cancer has been reported to be lower in women with early childbirth than in women with late childbirth. To verify the effect of childbirth and the age at first childbirth on carcinogenesis and progression of breast cancer, we induced breast cancer by 7,12-dimethylbenanthracene (DMBA) in 120 female Sprague-Dawley (SD) rats, and divided them into control or experimental (DMBA-treated) nulliparous, early childbirth, and late childbirth groups to observe the incidence, latency, and size of breast cancer. Argyrophilic nucleolar organizer regions (AgNOR) count and the expression of C-erbB-2, proliferating cell nuclear antigen (PCNA), Ki-67, and minichromosome maintenance protein 2 (MCM2) in breast cancer tissues were detected by immunohistochemistry. The breast cancer incidences were 95.0%, 16.7%, and 58.8% in the experimental nulliparous, early childbirth, and late childbirth groups, respectively (all P induced breast cancer.

  13. Reducing the weight of cancer: mechanistic targets for breaking the obesity-carcinogenesis link.

    Science.gov (United States)

    Hursting, Stephen D; Lashinger, Laura M; Wheatley, Karrie W; Rogers, Connie J; Colbert, Lisa H; Nunez, Nomeli P; Perkins, Susan N

    2008-08-01

    The prevalence of obesity, an established epidemiologic risk factor for many cancers, has risen steadily for the past several decades in the US. The increasing rates of obesity among children are especially alarming and suggest continuing increases in the rates of obesity-related cancers for many years to come. Unfortunately, the mechanisms underlying the association between obesity and cancer are not well understood. In particular, the effects on the carcinogenesis process and mechanistic targets of interventions that modulate energy balance, such as reduced-calorie diets and physical activity, have not been well characterized. The purpose of this review is to provide a strong foundation for the translation of mechanism-based research in this area by describing key animal and human studies of energy balance modulations involving diet or physical activity and by focusing on the interrelated pathways affected by alterations in energy balance. Particular attention is placed on signaling through the insulin and insulin-like growth factor-1 receptors, including components of the Akt and mammalian target of rapamycin (mTOR) signaling pathways downstream of these growth factor receptors. These pathways have emerged as potential targets for disrupting the obesity-cancer link. The ultimate goal of this work is to provide the missing mechanistic information necessary to identify targets for the prevention and control of cancers related to or caused by excess body weight.

  14. Rat Urinary Bladder Carcinogenesis by Dual-Acting PPARα+γ Agonists

    Directory of Open Access Journals (Sweden)

    Martin B. Oleksiewicz

    2008-01-01

    Full Text Available Despite clinical promise, dual-acting activators of PPARα and γ (here termed PPARα+γ agonists have experienced high attrition rates in preclinical and early clinical development, due to toxicity. In some cases, discontinuation was due to carcinogenic effect in the rat urothelium, the epithelial layer lining the urinary bladder, ureters, and kidney pelvis. Chronic pharmacological activation of PPARα is invariably associated with cancer in rats and mice. Chronic pharmacological activation of PPARγ can in some cases also cause cancer in rats and mice. Urothelial cells coexpress PPARα as well as PPARγ, making it plausible that the urothelial carcinogenicity of PPARα+γ agonists may be caused by receptor-mediated effects (exaggerated pharmacology. Based on previously published mode of action data for the PPARα+γ agonist ragaglitazar, and the available literature about the role of PPARα and γ in rodent carcinogenesis, we propose a mode of action hypothesis for the carcinogenic effect of PPARα+γ agonists in the rat urothelium, which combines receptor-mediated and off-target cytotoxic effects. The proposed mode of action hypothesis is being explored in our laboratories, towards understanding the human relevance of the rat cancer findings, and developing rapid in vitro or short-term in vivo screening approaches to faciliate development of new dual-acting PPAR agonist compounds.

  15. Radionuclides in cigarettes may lead to carcinogenesis via p16{sup INK4a} inactivation

    Energy Technology Data Exchange (ETDEWEB)

    Prueitt, Robyn L.; Goodman, Julie E. [Gradient Corporation, 20 University Road, Cambridge, MA 02138 (United States); Valberg, Peter A. [Gradient Corporation, 20 University Road, Cambridge, MA 02138 (United States)], E-mail: pvalberg@gradientcorp.com

    2009-02-15

    It is widely accepted that tobacco smoke is responsible for the vast majority of lung cancers worldwide. There are many known and suspected carcinogens present in cigarette smoke, including {alpha}-emitting radioisotopes. Epidemiologic studies have shown that increased lung cancer risk is associated with exposure to ionizing radiation, and it is estimated that the majority of smoking-induced lung cancers may be at least partly attributable to the inhaled and deposited radiation dose from radioisotopes in the cigarette smoke itself. Recent research shows that silencing of the tumor suppressor gene p16{sup INK4a} (p16) by promoter methylation plays a role in smoking-related lung cancer. Inactivation of p16 has also been associated with lung cancer incidence in radiation-exposed workers, suggesting that radionuclides in cigarette smoke may be acting with other compounds to cause smoking-induced lung cancer. We evaluated the mechanism of ionizing radiation as an accepted cause of lung cancer in terms of its dose from tobacco smoke and silencing of p16. Because both radiation and cigarette smoking are associated with inactivation of p16, and p16 inactivation has been shown to play a major role in carcinogenesis, ionizing radiation from cigarette smoke likely plays a role in lung cancer risk. How large a role it plays, relative to chemical carcinogens and other modes of action, remains to be elucidated.

  16. Fifty years of tobacco carcinogenesis research: from mechanisms to early detection and prevention of lung cancer.

    Science.gov (United States)

    Hecht, Stephen S; Szabo, Eva

    2014-01-01

    The recognition of the link between cigarette smoking and lung cancer in the 1964 Surgeon General's Report initiated definitive and comprehensive research on the identification of carcinogens in tobacco products and the relevant mechanisms of carcinogenesis. The resultant comprehensive data clearly illustrate established pathways of cancer induction involving carcinogen exposure, metabolic activation, DNA adduct formation, and consequent mutation of critical genes along with the exacerbating influences of inflammation, cocarcinogenesis, and tumor promotion. This mechanistic understanding has provided a framework for the regulation of tobacco products and for the development of relevant tobacco carcinogen and toxicant biomarkers that can be applied in cancer prevention. Simultaneously, the recognition of the link between smoking and lung cancer paved the way for two additional critical approaches to cancer prevention that are discussed here: detection of lung cancer at an early, curable stage, and chemoprevention of lung cancer. Recent successes in more precisely identifying at-risk populations and in decreasing lung cancer mortality with helical computed tomography screening are notable, and progress in chemoprevention continues, although challenges with respect to bringing these approaches to the general population exist. Collectively, research performed since the 1964 Report demonstrates unequivocally that the majority of deaths from lung cancer are preventable.

  17. Potent chemopreventive effect of mangiferin on lung carcinogenesis in experimental Swiss albino mice

    Directory of Open Access Journals (Sweden)

    Peramaiyan Rajendran

    2014-01-01

    Full Text Available Aim of the Study: In the present study the effects of mangiferin were tested against lung cancer-bearing mice in both the pre-initiation and post-initiation periods. Materials and Methods: Healthy male Swiss albino mice (6-8 weeks old were used throughout the study. The animals were treated with mangiferin (100 mg/kg body weight dissolved in corn oil two weeks before (pre-initiation and the twelfth week after (post-initiation the establishment of B (a P (50 mg/kg body weight-induced lung carcinoma. Results: The body weight decreased and the lung weight and levels of xenobiotic and liver marker enzymes markedly increased in the carcinogen-administered animals; and mangiferin treatment brought the values of these parameters back to the near-normal ones. The activities of lysosomal enzymes in the animals with B (a P-induced experimental lung carcinogenesis were also assessed. In these animals there was an increase in the activities of lysosomal enzymes such as acidphosphatase, β-glucuronidase, N-acetyl glucosaminidase, and β-galactosidase. Conclusion: Supplementation with mangiferin attenuated all these alterations, thus indicating its anticancer effect. Overall, the above data showed that the anticancer effect of mangiferin as a chemopreventive agent was pronounced.

  18. Smoking-promoted oxidative DNA damage response is highly correlated to lung carcinogenesis.

    Science.gov (United States)

    Cao, Chao; Lai, Tianwen; Li, Miao; Zhou, Hongbin; Lv, Dan; Deng, Zaichun; Ying, Songmin; Chen, Zhihua; Li, Wen; Shen, Huahao

    2016-04-05

    Oxidative stress induced by tobacco smoking is one of the main causes of DNA damage and is known to be involved in various cancers. Smoking is the leading cause of lung cancer, while the role of cigarette smoke-induced oxidative DNA damage response during lung carcinogenesis is largely unknown. In this study, we investigated oxidative DNA damage response levels in smoking and nonsmoking patients with lung cancer, and evaluated the potential diagnostic value of 8-OHdG for lung cancer. We observed a higher level of 8-OHdG expression and secretion in airways of lung cancer patients than that of noncancer controls. 8-OHdG expression was associated with the TNM stages. Additionally, cigarette smoke-induced oxidative DNA damage response was observed in bronchial epithelial cells in vitro and in vivo. A statistical significance correlation was found between the levels of 8-OHdG and smoking index. With a cut-off value of 2.86 ng/ml, 8-OHdG showed a sensitivity and specificity of 70.0% and 73.7%, respectively, to identify a patient with lung cancer. These findings not only underscore the importance of smoking in oxidative DNA damage response of lung cancer patients, but also suggest 8-OHdG as a potential diagnostic biomarker for lung cancer.

  19. Imbalance between apoptosis and cell proliferation during early stages of mammary gland carcinogenesis in ACI rats

    Energy Technology Data Exchange (ETDEWEB)

    Kutanzi, Kristy R.; Koturbash, Igor [Department of Biological Sciences, University of Lethbridge, Lethbridge, AB, T1K3M4 (Canada); Bronson, Roderick T. [Department of Pathology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115 (United States); Pogribny, Igor P., E-mail: igor.pogribny@fda.hhs.gov [Division of Biochemical Toxicology, National Center for Toxicological Research, Jefferson, AR 72079 (United States); Kovalchuk, Olga, E-mail: olga.kovalchuk@uleth.ca [Department of Biological Sciences, University of Lethbridge, Lethbridge, AB, T1K3M4 (Canada)

    2010-12-10

    Estrogen and ionizing radiation are well-documented human breast carcinogens, yet the exact mechanisms of their deleterious effects on mammary gland remain to be discerned. Here we analyze the balance between cellular proliferation and apoptosis in the mammary glands of rats exposed to estrogen and X-ray radiation and the combined action of these carcinogenic agents. For the first time, we show that combined exposure to estrogen and radiation has a synergistic effect on cell proliferation in the mammary glands of ACI rats, as evidenced by a substantially greater magnitude of cell proliferation, especially after 12 and 18 weeks of treatment, when compared to mammary glands of rats exposed to estrogen or radiation alone. We also demonstrate that an imbalance between cell proliferation and apoptosis, rather than enhanced cell proliferation or apoptosis suppression alone, may be a driving force for carcinogenesis. Our studies further suggest that compromised functional activity of p53 may be one of the mechanisms responsible for the proliferation/apoptosis imbalance. In sum, the results of our study indicate that evaluation of the extent of cell proliferation and apoptosis before the onset of preneoplastic lesions may be a potential biomarker of breast cancer risk after exposure to breast carcinogens.

  20. Modeling Lung Carcinogenesis in Radon-Exposed Miner Cohorts: Accounting for Missing Information on Smoking.

    Science.gov (United States)

    van Dillen, Teun; Dekkers, Fieke; Bijwaard, Harmen; Brüske, Irene; Wichmann, H-Erich; Kreuzer, Michaela; Grosche, Bernd

    2016-05-01

    Epidemiological miner cohort data used to estimate lung cancer risks related to occupational radon exposure often lack cohort-wide information on exposure to tobacco smoke, a potential confounder and important effect modifier. We have developed a method to project data on smoking habits from a case-control study onto an entire cohort by means of a Monte Carlo resampling technique. As a proof of principle, this method is tested on a subcohort of 35,084 former uranium miners employed at the WISMUT company (Germany), with 461 lung cancer deaths in the follow-up period 1955-1998. After applying the proposed imputation technique, a biologically-based carcinogenesis model is employed to analyze the cohort's lung cancer mortality data. A sensitivity analysis based on a set of 200 independent projections with subsequent model analyses yields narrow distributions of the free model parameters, indicating that parameter values are relatively stable and independent of individual projections. This technique thus offers a possibility to account for unknown smoking habits, enabling us to unravel risks related to radon, to smoking, and to the combination of both.

  1. HMGA1 drives metabolic reprogramming of intestinal epithelium during hyperproliferation, polyposis, and colorectal carcinogenesis.

    Science.gov (United States)

    Williams, Michael D; Zhang, Xing; Belton, Amy S; Xian, Lingling; Huso, Tait; Park, Jeong-Jin; Siems, William F; Gang, David R; Resar, Linda M S; Reeves, Raymond; Hill, Herbert H

    2015-03-01

    Although significant progress has been made in the diagnosis and treatment of colorectal cancer (CRC), it remains a leading cause of cancer death worldwide. Early identification and removal of polyps that may progress to overt CRC is the cornerstone of CRC prevention. Expression of the High Mobility Group A1 (HMGA1) gene is significantly elevated in CRCs as compared with adjacent, nonmalignant tissues. We investigated metabolic aberrations induced by HMGA1 overexpression in small intestinal and colonic epithelium using traveling wave ion mobility mass spectrometry (TWIMMS) in a transgenic model in which murine Hmga1 was misexpressed in colonic epithelium. To determine if these Hmga1-induced metabolic alterations in mice were relevant to human colorectal carcinogenesis, we also investigated tumors from patients with CRC and matched, adjacent, nonmalignant tissues. Multivariate statistical methods and manual comparisons were used to identify metabolites specific to Hmga1 and CRC. Statistical modeling of data revealed distinct metabolic patterns in Hmga1 transgenics and human CRC samples as compared with the control tissues. We discovered that 13 metabolites were specific for Hmga1 in murine intestinal epithelium and also found in human CRC. Several of these metabolites function in fatty acid metabolism and membrane composition. Although further validation is needed, our results suggest that high levels of HMGA1 protein drive metabolic alterations that contribute to CRC pathogenesis through fatty acid synthesis. These metabolites could serve as potential biomarkers or therapeutic targets.

  2. Morphological and quantitative analysis of BCL6 expression in human colorectal carcinogenesis.

    Science.gov (United States)

    Sena, Paola; Mariani, Francesco; Benincasa, Marta; De Leon, Maurizio Ponz; Di Gregorio, Carmela; Mancini, Stefano; Cavani, Francesco; Smargiassi, Alberto; Palumbo, Carla; Roncucci, Luca

    2014-01-01

    The aim of the present study was to determine whether BCL6 is expressed during malignant transformation of the large bowel and to assess whether, and to what extent, immunoreactivity is related to the different stages of neoplastic progression. Samples of normal colorectal mucosa (n=22), microadenomas (n=22) and colorectal cancer (n=22), were analyzed by immunohistochemistry, immunofluorescence coupled with confocal microscopy and western blotting. Our results clearly outlined the marked increase occurring in both intensity and density of BCL6 protein expression in the normal mucosa-microadenoma-carcinoma sequence. Immunohistochemistry and immunofluorescence analyses showed that BCL6 is expressed at low levels in normal mucosa and increases in microadenoma and in cancer with statistical significance. These results were confirmed by western blotting data. The increasing expression of BCL6 in human colorectal cancer development suggests the involvement of BCL6 in tumor progression, from the earliest stages of carcinogenesis with significant increase in cancer. The enhanced understanding of the biological role of BCL6, previously shown to exert a key role in lymphomagenesis, may lead to a re-evaluation of this protein and may highlight the importance of performing further studies in order to identify novel therapeutic targets for colorectal cancer.

  3. GSTM1, GSTT1, and NQO1 polymorphisms in cervical carcinogenesis.

    Science.gov (United States)

    Nunobiki, Osamu; Ueda, Masatsugu; Akise, Hikari; Izuma, Shinji; Torii, Kiyo; Okamoto, Yoshiaki; Tanaka, Ichiro; Noda, Sadamu; Akashi, Kyoko; Higashida, Taro

    2015-07-01

    The aim of the study is to investigate the clinical significance of glutathione-S-transferase GSTM1, GSTT1, and NQO1 c.609C>T (rs1800566) genetic polymorphisms in cervical carcinogenesis. GSTM1, GSTT1, and NQO1 polymorphisms together with human papillomavirus (HPV) types were examined in a total of 192 cervical smear in exfoliated cervical cell samples using polymerase chain reaction (PCR) system and real-time polymerase chain reaction (PCR) system. The 19 patients with high-grade squamous intraepithelial lesion had statistically higher frequency of null GSTT1 genotype than 9 with low-grade squamous intraepithelial lesion (LSIL) among the 67 patients with high-risk HPV (P = 0.024). The 24 patients with HSIL had also statistically higher frequency of NQO1 (CT+TT) genotype than 14 with LSIL among the 67 patients with high-risk HPV (P = 0.024). GSTT1 null and NQO1 genotype in cervical cell samples may be associated with more severe precancerous lesions of the cervix in a Japanese population.

  4. EXPRESSION OF P16 AND CYCLIN D1 IN THE COURSE OF CARCINOGENESIS OF THE STOMACH

    Institute of Scientific and Technical Information of China (English)

    CHEN Yu-long; XU Feng; LI Yan-jie

    1999-01-01

    Objective: To determine p16 and cyclin D1 expression in the specimen of gastric carcinoma, atypic hyperplasia, atrophic gastritis, superficial gastritis and normal gastric mucosa. Methods: Using immunohistochemical method (ABC), the samples of 58 adenocarcinomas, 22 atypic hyperplasias, 28 atrophic gastritis,27 superficial gastritis and 15 gastric epitheliums were analyzed. Results: Positive immunostaining rate for p16 protein was the highest in normal gastric mucosa and decreased with the lesions progressing from superficial gastritis to atrophic gastritis to atypital hyperplasia and to adenocarcinoma (85%, 78.6%, 31.8%,48.3% respectively); Positive immunostaining of cyclin D1 can observed in atrophic gastritis. With the lesions progressing from atrophic gastritis to atypical hyperplasia to adenocarcinoma, its expression rate increased (17.9%, 36.4%, 53.4% respectively), and there was a significant difference between adenocarcinoma and atrophic gastritis group (P<0.05). An interesting observation was that inverse expression between p16and cyclin D1, was shown in most of gastric cancer detected. Conclusion: It is indicated that p16 and cyclin D1 play an important role in the gastric carcinogenesis, the inverse expression between p16 and cyclin D1 suggested that there is a suppression trend in them.

  5. Fundamental concepts of mathematics

    CERN Document Server

    Goodstein, R L

    Fundamental Concepts of Mathematics, 2nd Edition provides an account of some basic concepts in modern mathematics. The book is primarily intended for mathematics teachers and lay people who wants to improve their skills in mathematics. Among the concepts and problems presented in the book include the determination of which integral polynomials have integral solutions; sentence logic and informal set theory; and why four colors is enough to color a map. Unlike in the first edition, the second edition provides detailed solutions to exercises contained in the text. Mathematics teachers and people

  6. Combining pharmacophore search, automated docking, and molecular dynamics simulations as a novel strategy for flexible docking. Proof of concept: docking of arginine-glycine-aspartic acid-like compounds into the alphavbeta3 binding site.

    Science.gov (United States)

    Moitessier, Nicolas; Henry, Christophe; Maigret, Bernard; Chapleur, Yves

    2004-08-12

    A novel and highly efficient flexible docking approach is presented where the conformations (internal degrees of freedom) and orientations (external degrees of freedom) of the ligands are successively considered. This hybrid method takes advantage of the synergistic effects of structure-based and ligand-based drug design techniques. Preliminary antagonist-derived pharmacophore determination provides the postulated bioactive conformation. Subsequent docking of this pharmacophore to the receptor crystal structure results in a postulated pharmacophore/receptor binding mode. Pharmacophore-oriented docking of antagonists is subsequently achieved by matching ligand interacting groups with pharmacophore points. Molecular dynamics in water refines the proposed complexes. To validate the method, arginine-glycine-aspartic acid (RGD) containing peptides, pseudopeptides, and RGD-like antagonists were docked to the crystal structure of alphavbeta3 holoprotein and apoprotein. The proposed directed docking was found to be more accurate, faster, and less biased with respect to the protein structure (holo and apoprotein) than DOCK, Autodock, and FlexX docking methods. The successful docking of an antagonist recently cocrystallized with the receptor to both apo and holoprotein is particularly appealing. The results summarized in this report illustrated the efficiency of our light CoMFA/rigid body docking hybrid method.

  7. Terahertz molecular resonance of cancer DNA

    Science.gov (United States)

    Cheon, Hwayeong; Yang, Hee-Jin; Lee, Sang-Hun; Kim, Young A.; Son, Joo-Hiuk

    2016-11-01

    Carcinogenesis involves the chemical and structural alteration of biomolecules in cells. Aberrant methylation of DNA is a well-known carcinogenic mechanism and a common chemical modification of DNA. Terahertz waves can directly observe changes in DNA because the characteristic energies lie in the same frequency region. In addition, terahertz energy levels are not high enough to damage DNA by ionization. Here, we present terahertz molecular resonance fingerprints of DNA methylation in cancer DNA. Methylated cytidine, a nucleoside, has terahertz characteristic energies that give rise to the molecular resonance of methylation in DNA. Molecular resonance is monitored in aqueous solutions of genomic DNA from cancer cell lines using a terahertz time-domain spectroscopic technique. Resonance signals can be quantified to identify the types of cancer cells with a certain degree of DNA methylation. These measurements reveal the existence of molecular resonance fingerprints of cancer DNAs in the terahertz region, which can be utilized for the early diagnosis of cancer cells at the molecular level.

  8. Molecular vibrational generalized inverse theory and its software

    Institute of Scientific and Technical Information of China (English)

    郑重德

    1995-01-01

    The general concept of flexibility and activity are presented,the generalized inverse theory of molecular vibrations is set up,and the computation software of molecular flexibilities and normal coordinates(MFNC)is elaborately programed.

  9. Intellect and Concept

    Directory of Open Access Journals (Sweden)

    Gurpreet Rattan

    2010-11-01

    Full Text Available The connections between theories of concepts and issues of knowledge and epistemic normativity are complex and controversial. According to the general, broadly Fregean, view that stands in the background of this paper, these connections are taken not only to exist, but also to be fundamental to issues about the individuation of concepts. This kind of view fleshed out should clarify the nature and role of epistemic norms, and of different kinds of epistemic norms, in concept individuation. This paper takes up an aspect of this general task and tries to make explicit the nature and role of intellectual norms, and to argue that extant paradigms for theorizing concepts fail because they fail to recognize the nature and individuative relevance of intellectual norms.

  10. Common tester platform concept.

    Energy Technology Data Exchange (ETDEWEB)

    Hurst, Michael James

    2008-05-01

    This report summarizes the results of a case study on the doctrine of a common tester platform, a concept of a standardized platform that can be applicable across the broad spectrum of testing requirements throughout the various stages of a weapons program, as well as across the various weapons programs. The common tester concept strives to define an affordable, next-generation design that will meet testing requirements with the flexibility to grow and expand; supporting the initial development stages of a weapons program through to the final production and surveillance stages. This report discusses a concept investing key leveraging technologies and operational concepts combined with prototype tester-development experiences and practical lessons learned gleaned from past weapons programs.

  11. Decoding Astronomical Concepts

    Science.gov (United States)

    Durisen, Richard H.; Pilachowski, Catherine A.

    2004-01-01

    Two astronomy professors, using the Decoding the Disciplines process, help their students use abstract theories to analyze light and to visualize the enormous scale of astronomical concepts. (Contains 5 figures.)

  12. The Concept of Alexithymia

    Directory of Open Access Journals (Sweden)

    Miray Sasioglu

    2013-08-01

    Full Text Available The concept of alexithymia, which means “no words for emotions”, emerged in order to explain the symptoms of psychosomatic patients and gained a quick recognition among psychiatrists. However, current studies indicate that alexithymia may be a personality trait seen both in different pathological groups and even in healthy population. At this point, many researches have been made in order to distinguish alexithymia from existing constructs and diagnosis, and to remove the questions on reliability and validity of the con-cept and its measurement. Ongoing discussions on alexithymia will be re-viewed in this study. The controversial concept of alexithymia will be exam-ined in terms of characteristics, theoretical background, relationship with the other disorders, measurement and the critique of the measurement and the concept.

  13. Concepts in Change

    Science.gov (United States)

    Rusanen, Anna-Mari; Pöyhönen, Samuli

    2013-06-01

    In this article we focus on the concept of concept in conceptual change. We argue that (1) theories of higher learning must often employ two different notions of concept that should not be conflated: psychological and scientific concepts. The usages for these two notions are partly distinct and thus straightforward identification between them is unwarranted. Hence, the strong analogy between scientific theory change and individual learning should be approached with caution. In addition, we argue that (2) research in psychology and cognitive science provides a promising theoretical basis for developing explanatory mechanistic models of conceptual change. Moreover, we argue that (3) arguments against deeper integration between the fields of psychology and conceptual change are not convincing, and that recent theoretical developments in the cognitive sciences might prove indispensable in filling in the details in mechanisms of conceptual change.

  14. Magnetismo Molecular (Molecular Magentism)

    Energy Technology Data Exchange (ETDEWEB)

    Reis, Mario S [Universidade Federal Fluminense, Brasil; Moreira Dos Santos, Antonio F [ORNL

    2010-07-01

    The new synthesis processes in chemistry open a new world of research, new and surprising materials never before found in nature can now be synthesized and, as a wonderful result, observed a series of physical phenomena never before imagined. Among these are many new materials the molecular magnets, the subject of this book and magnetic properties that are often reflections of the quantum behavior of these materials. Aside from the wonderful experience of exploring something new, the theoretical models that describe the behavior these magnetic materials are, in most cases, soluble analytically, which allows us to know in detail the physical mechanisms governing these materials. Still, the academic interest in parallel this subject, these materials have a number of properties that are promising to be used in technological devices, such as in computers quantum magnetic recording, magnetocaloric effect, spintronics and many other devices. This volume will journey through the world of molecular magnets, from the structural description of these materials to state of the art research.

  15. Concepts of classical optics

    CERN Document Server

    Strong, John

    2004-01-01

    An intermediate course in optics, this volume explores both experimental and theoretical concepts, offering practical knowledge of geometrical optics that will enhance students' comprehension of any relevant applied science. Its exposition of the concepts of classical optics is presented with a minimum of mathematical detail but presumes some knowledge of calculus, vectors, and complex numbers.Subjects include light as wave motion; superposition of wave motions; electromagnetic waves; interaction of light and matter; velocities and scattering of light; polarized light and dielectric boundarie

  16. The AERA Concept.

    Science.gov (United States)

    1981-03-24

    electrgnic tabular displays ( ETABS ). - , This concept document was prepared by a team of ATC experts to review prior work, the on-going AERA program, and to...Address Beacon System (DABS), trajectory modeling and planning algorithms, and electronic tabular displays ( ETABS ). This concept document was...capability, and a Flight Management System. The development of AERA requires major efforts in system design and software and man-machine interface

  17. Concept medium programme

    DEFF Research Database (Denmark)

    Bjerrum, Peter

    2005-01-01

    The present essay is an attempt to determine the architectural project of the 21st century in relation to a modern conception of space as the medium of architecture, and of sociality as its program......The present essay is an attempt to determine the architectural project of the 21st century in relation to a modern conception of space as the medium of architecture, and of sociality as its program...

  18. Concept medium program

    DEFF Research Database (Denmark)

    Bjerrum, Peter

    2003-01-01

    The present essays is an attempt to dertermine the architecural project of the 21st century in realation to a modern conception of space as the medium of architecture, and of society as its program. This attempt adopts the internal point of view of an architect in describing a modern architectural...... project within the framework: concept - program, these notions being concieved as spatial representations primarily and immediately "given" to architecture....

  19. [Mindfulness: A Concept Analysis].

    Science.gov (United States)

    Chen, Tsai-Ling; Chou, Fan-Hao; Wang, Hsiu-Hung

    2016-04-01

    "Mindfulness" is an emerging concept in the field of healthcare. Ranging from stress relief to psychotherapy, mindfulness has been confirmed to be an effective tool to help individuals manage depression, anxiety, obsessive-compulsive disorder, and other health problems in clinical settings. Scholars currently use various definitions for mindfulness. While some of these definitions overlap, significant differences remain and a general scholarly consensus has yet to be reached. Several domestic and international studies have explored mindfulness-related interventions and their effectiveness. However, the majority of these studies have focused on the fields of clinical medicine, consultation, and education. Mindfulness has rarely been applied in clinical nursing practice and no related systematic concept analysis has been conducted. This paper conducts a concept analysis of mindfulness using the concept analysis method proposed by Walker and Avant (2011). We describe the defining characteristics of mindfulness, clarify the concept, and confirm the predisposing factors and effects of mindfulness using examples of typical cases, borderline cases, related cases, and contrary case. Findings may provide nursing staff with an understanding of the concept of mindfulness for use in clinical practice in order to help patients achieve a comfortable state of body and mind healing.

  20. Idiopathic scoliosis: etiological concepts and hypotheses

    OpenAIRE

    2013-01-01

    Scoliosis is diagnosed as idiopathic in 70 % of structural deformities affecting the spine in children and adolescents, probably reflecting our current misunderstanding of this disease. By definition, a structural scoliosis should be the result of some primary disorder. The goal of this article is to give a comprehensive overview of the currently proposed etiological concepts in idiopathic scoliosis regarding genetics, molecular biology, biomechanics, and neurology, with particular emphasis o...